J
£-
Norfh Carolina State Library
Raleigh
NORTH CAROLINA GEOLOGICAL SURVEY
J. A. HOLMES, STATE GEOLOGIST.
l- =
BULLETIN No. 9
MONAZITE, AND MONAZITE DEPOSITS
IN NORTH CAROLINA.
BY
HENRY B. C. NITZE,
Assistant Geologist.
WINSTON :
M. I. & J. C. Stewart, Public Printers.
1895.
I
A
r
TABLE OF CONTENTS.
PAGE
Letter of Transmittal 5
Brief Description of the Mineral 6
Historical Sketch and Nomenclature 6
Crystallography 10
Morphological 10
Physical 12
Optical 13
Chemical Composition '. 14
Composition and analyses 14
Method of analysis 21
Chemical and blowpipe reactions 22
Micro-chemical reactions 23
Spectroscopic tests 23
Chemical molecular constitution 24
Artificial production 25
Geological and Geographical Occurrence. 25
Accessory minerals , 30
Economical Use 30
Methods of Extraction and Concentration 31
Output and Value of Monazite in the United States 35
Bibliography 38
Index 44
ILLUSTRATIONS.
Plate I. Prospecting for and mining monazite sand Frontispiece
" II. Map, showing workable monazite area in the Carolinas... 28
" III. Washing stream gravel for monazite, Lattimore mine,
Cleveland county, N. C 30
" IV. Mining and washing gravel beds for monazite, Lattimore
mine, Cleveland county, N. C 33
V. Mining and washing hillside soil for monazite, Pheifer
mine, Cleveland county, N. C 34
L
LETTER OF TRANSMITTAL.
Raleigh, N. C, June 1st, 1895.
To His Excellency, Hon. Elias Carr,
Governor of Worth Carolina.
Sir : — I have the honor to submit for publication as Bulletin 9
of the Geological Survey, a preliminary report on Monazite and
Monazite Deposits in North Carolina, by Mr. Henry B. C. Nitze.
The publication of this bulletin will serve as an answer to the
many enquiries received by the Survey for information on this
subject.
Yours obediently,
J. A. Holmes,
State Geologist.
MONAZITE
By H. B. C. JSIitze.
BRIEF DESCRIPTION OF THE MINERAL.
Monazite is essentially an anhydrous phosphate of the rare
earths cerium, lanthanum, and didymium ( Ce, La, Di ), P04. It
also contains, almost invariably, small percentages of thoria (Th02)
and silicic acid ( Si02), which may be present in combination as
thorite or orangite ( ThSiOJ, or the thoria may exist as the phos-
phate, either in combination with the cerium, etc., or as an isomor-
phous mixture. Other occasional accessory constituents are the
yttrium and erbium earths, zirconia, alumina, magnesia, lime, iron
oxides ( Fe203 and FeO ), manganous oxide, tin and lead oxides,
fluorine, titanic acid, and water, usually in fractional percentages.
It is a subtranslucent to subtransparent mineral, light yellow,
reddish yellow, brownish, or greenish in color, and has a resinous
luster. It is brittle with conchoidal to uneven fracture. Its hard-
ness is from 5 to 5.5, and its specific gravity from 4.9 to 5.3. It
crystallizes in the monoclinic system.
HISTORICAL SKETCH AND NOMENCLATURE.
The following names have been applied to the mineral by inde-
pendent discoverers and workers : Turnerite, monazite, mengite,
edwardsite, eremite, cryptolite, monazitoid, phosphocerite, urdite,
and kararfveite. It was not long, however, before the identity of
these newly described mineral species was recognized, and at the
present time the general name in use is monazite.
The name "turnerite " was given in 1823 by A. Levy1 in honor
of the English chemist, E. II. Turner, in whose collection the first
specimens were found. The locality of these was Dauphiny. They
had been classed as sphene, on account of their color, accompani-
!The Annals of Philosophy, London, 1823, vol. 5, p. 841.
b MONAZITE, AND MONAZITE DEPOSITS
ment ( adularia and lamellary crichtonite ), and the locality ; but
Levy found their hardness to be less than that of sphene, and a
good cleavage in one direction. He gives as the primary crystal-
lographic form an oblique rhombic prism with differment dimen-
sions from that of sphene. G. vom Rath1 has also called attention
to the fact that titanite ( sphene ) may be confounded with tunerite
from general resemblance. In the fifth edition of his Mineralogy
(American edition, Boston, 1844) Phillips says that monazite is
occasionally known among mineralogists under the name of " pic-
tite," which is one of the early names for titanite, with which it
was doubtless confounded.
The date 1823, then, may be taken as that of the earliest recog-
nition of a new mineral species which was later shown to be iden-
tical with monazite. Thus, in 1866, J. D. Dana2 demonstrated
the identity between turnerite and monazite by similarity of crys-
tal form and physical properties. No chemical examination of
turnerite had yet been made at that time. In 1870 this was sub-
stantiated by G. vom Rath,3 and although he recognized the priority
of Levy's name, turnerite, he did not feel justified in abandoning
the name monazite, inasmuch as the latter belonged to a chemi-
cally as well as a crystallographically known mineral, while the
composition of turnerite was not yet so well known. In 1873 Des
Cloizeaux,4 by the orientation of the optical axes, and Pisani,4 by
the chemical determination of P205 and Ce203, concluded that
monazite and turnerite were the same species. In 1876 Trechmann5
showed that the optical properties of turnerite and monazite were
the same. In 1826 Menge discovered some crystals in the Ilmen
mountains, near Miask, Siberia, which he held for a variety of
zircon. Fiedler6 gives the more exact locality of these specimens
as being not in the Ilmen mountains proper, but in their southern
extension, in the so-called Tscheremtchanka. The first scientific
description of these was given by Breithaupt7 in 1829. He gave it
the name, "monazite" ( monazit, monacite), from the Greek?
iPoggendorff, Annalen, 1864, vol. 122, p. 407.
2Am. Jour. Sci. vol. 42, 1866, p. 420.
spoggendorff, Annalen, Erg.- Ed. 5, 1871: p. 413; Sitzungsber. Bayer. Akad. Wiss., 1S70,
vol. 2, p. 271.
^Zeitscher. Deutscher. geol. Gesell., Berlin, vol. 25, 1873, p. 568.
5Xeues Jahrbuch, 1876, p. 593.
epoggendorff, Annalen, 1832, vol. 25, p. 332.
7Schweigger-Seidel, Journal der Chenrie u. Physik, 1829, vol. 55, part 3, p. 301
IN NORTH CAROLINA. 9
meaning " to be solitary." In 1831 H. J. Brooke1, in describing
specimens from Menge's locality in the Urals, gave the name men-
gite, in honor of the discoverer.
Prof. C. U. Shepard2 in 1837 gave a description of " edwardsite,"
a new mineral from Norwich, Connecticut, which he named in
honor of the governor of the State. Later in the year3 he
described another new mineral from Watertown, Connecticut,
under the name of " eremite," after the Greek, meaning " soli-
tude," but he did not then recognize its identity with edwardsite.
Prof. J. D. Dana published in 1838 his crystallographic measure-
ments of eremite, which agree with those of monazite.4 In 1840
Gustav Rose5 proved the identity, crystallographically and physi-
cally, of edwardsite and monazite. And in the second edition of
his Mineralogy (1814) Shepard places both edwardsite and eremite
under the head of monazite.
In 1842 Rose6 gave a detailed description of the Russian mona-
zite.
Woehler,7 in 1846, discovered some small needle-like crystals
invisibly included in the apatite of Arendal, Norway. They were
of a pale-yellow color, specific gravity approximately 4.6, and, accord-
ing to analysis, were composed of phosphate of cerium, but contained
no thoria, and in this he distinguished the mineral from monazite,
calling it "cryptolite," from the Greek, meaning "concealed."
Although the forms of these crystals are different in appearance
from that of ordinary monazite, Mallard,8 in 1887, by careful gonio-
metric measurements, established the identity of the two minerals.
Hermann,9 in 1847, applied the name "monazitoid" to certain
brown colored bent and broken crystals, of the specific gravity 5.28,
from Lake Ilmen, near Miask, which contain less phosphoric acid
(only 18.7) than monazite, besides some tantalic acid (3.75 to 6.27
per cent). Kokscharow10 believed that monazitoid was simply impure
iPoggendorff, Annalen, 1831, vol. 23, p. 362; Philos. Mag. and Annals, vol. 10, p. 187.
2Am. Jour. Sci. (1), 1837, vol. 32, p. 162; Poggendorfl, Annalen, 1838, vol. 43, p. 148.
3Am. Jour. Sci. (1), 1837, vol. 32, p. 341.
4 Am. Jour. Sci. (1), vol. 33, 1838. p. 70.
5Poggendorff, Annalen, 1840, vol. 49, p. 223.
6Reise nach dem Ural und Altai, voJ. 2, p. 87 and 482, Berlin, 1812.
^Poggendorff, Annalen, 1846, vol. 67, p. 424.
8Bull. Soc. Min., 1887, vol. 10, p. 236.
9Jour. prakt. Chemie, vol. 40, 1847, p. 21; Annuaire de Chemie, 1848, pp. 14'i.
10Materialien zur Mineralogie Russlands, vol. 4, 1862, pp. 7-34.
2
10 MONAZITE, AND MONAZITE DEPOSITS
monazite, the tantalic acid haying been derived from columbite and
samarskite, with which the crystals are intergrown.
Blomstrand1 analyzed specimens from probably the same locality
as Hermann's monazitoid, but found no tantalic acid.
In 1850 Watts2 described a new mineral occurring in the cobalt
ore of Johannisberg, Sweden, which he showed to be a phosphate
of cerium (including lanthanum and didymium). He proposed the
name "phospho-cerite." Its physical and chemical characters iden-
tify it beyond doubt with monazite.
Forbes and Dahll,3 in 1855, described a mineral occurring in the
granite of Urda, near Notero, Norway, under the name of "urdite,"
which E. Zschau4 determined to be monazite.
F. Radominski,5 in 1874, found a mineral inclosed in albite at
Kararfvet, near Falun, Sweden, which resembled monazite, but on
analysis was found to contain a notable quantity of fluorine (4.35
per cent), and for that reason he proposed to class it as a separate
species under the name "kararfveite." Blomstrand6 made an analy-
sis of specimens from the same locality, and found only 0.33 per
cent, fluorine. He concluded that it was but an impure form of
monazite.
CRYSTALLOGRAPHY.
MORPHOLOGICAL.
The primary form of monazite and its equivalents, turnerite,
edwardsite, and mengite, was early stated to be the oblique rhom-
bic prism of the monoclinic system. The crystallographic studies
of the mineral by Koksharow, Des Cloizeaux, Websky, Dana, Tom
Rath, and others have shown the occurrence of the following forms:
^eitschr. fur Kryst., vol. 20, 1892, p. 367, Lunds Universitets Arskrift, 1888 (24).
2Quart. Jour. Chem. Soc. London, 1850, vol. 2, p. 131.
Xyt Mag. Naturvidenskaberne, vol. 8, 1855, p. 227; Am. Jour. Sci., vol. 22, 1856, p. 262
4Allg. deutsche naturh. Zeitung, Dresden, 1857, p. 208; Am. Jour. Sci„ II, vol. 25, 1858 p 410
5Compt. Rend., 1874, vol. 78, p. 764.
,;Zeitsch. fur Kryst. vol. 19, 1891, p. 109; Geol. Foreningens Forhandl. Stockholm, 1889. vol
2, p. 174.
IN NORTH CAROLINA.
11
Observed forms of monazite.
Pinacoids.
Prisms.
Hemi-
domes.
Hemi-pyra-
mids.
oP
ocP
+ Poo
+ P
<*P^
00P2
_ Po^
— P
OoPod
00P3
— 7Pco
-HP
00P2
-|Poo
—IP
P^O
+ Pa
SPcX,
+2P§
iPob
+3Ps
+2P3
— 2P3
Of these, the more common forms are the ortho- and clino-pina-
coids and domes, the unit prism, and the unit pyramids. The basal
pinacoid is rare, having been observed only on crystals from the
Urals1 and from Alexander County, N. C.2
Among the rarer forms are: — |P~ol> found by Trechmann on tur-
nerite from the Einnenthal, Switzerland; — TP^o and — ^P, found
by Miers in Cornwall; and i-P^oo, on crystals from Nil St. Yincent,
Belgium, and western Siberia.
The usual crystal habit is tabular, parallel to 00 P~ob; also short
columnar, and sometimes elongated parallel to 00 P. Cryptolite
occurs always in very small crystals, elongated parallel to x> P.
The crystals are usually well developed and free from distortion.
They vary in size from the microscopic needles of cryptolite, wrhich
have a thickness of .004 to .016 mm. (0.00015 to 0.00062 inch), to
the abnormally large monazite crystals that have been found in
Amelia County, Va., 5 inches in length. The more general varia-
tion lies between one twentieth and 1 inch. Irregular masses of
monazite, devoid of crystal planes, as large as 15 to 20 pounds, have
been found in Amelia County, Ya., and in rounded masses up to
12| pounds at the Yilleneuve mica mine in Ottawa County, Quebec.
Twins are not common. The twinning plane is parallel to 00 P ^5;
als.o to oP (Zirkel, Yol. I, p. 432.) Twins are sometimes cruci-
form.
1N. von Koksharow, Materialien zur Mineralogie Russlands, vol. 4, 1862, pp. 7-34.
2G. von Rath, Zeitschr. fur Kryst., vol. 13, 1888, p. 596.
12
MONAZITE, AND MONAZITE DEPOSITS
The axial ratio has been determined on specimens from different
localities, as follows:
Axial ratios of monazite from various localities.
a
h
G
/3(oPA°oPob)
0.9742
1
0.9227
o /
103 46
0.9705
1
0.9221
103 46
0.9658
1
0.9217
103 28
0.9609
1
0.9081
103 26^
0.9693
1
0.9255
103 40
0.9735
1
0.9254
103 37
0.9718
1
0.9233
103 42
Localities.
Determined
by-
Watertown, Conn, (eremite) J. D. Dana.
Ural Mountains, Sanarka Koksharow.
Laacher See (turnerite) Vom Rath.
Hiddenite mine, N. C. Do.
Milhollands Mill, N. C E. S. Dana.
Schiittenhofen, Bohemia j Scharizer.
Nil St. Vincent Franck.
Some of the principal angular measurements are:
Angular measurements of monazite.
dPSd/^ccP
oP/\P»
ooPoo A oP
eoP£o/\P
CcPoOy^Pio
O / •/
o • //
O / '/
O ' s/
o • s,
43 25 0
76 14 0
39 20 0
43 18 30
37 11 0
76 14 0
59 37 0
39 03 0
43 12 30
37 12 30
76 32 0
59 42 30
39 20 30
43 17 10
37 07 40
76 20 0
59 40 0
39 12 30
43 25 0
37 03 0
76 23 0
59 36 0
39 20 0
Localities.
Measured
DV—
Watertown,Conn.,
(eremite).
Ural Mountains,
Sanarka.
Laacher See (tur-
nerite).
Milhollands Mill,
N. C
Schiitten h o f e n ,
Bohemia.
J. D. Dana.
Koksharow.
Vom Rath.
E. S. Dana.
Scharizer.
PHYSICAL CRYSTALLOGRAPHY.
The cleavage is most perfectly developed parallel to the basal
pinacoid (oP.); it is also distinct as a rule parallel to oo P^o ; some-
times parallel to ooPoo , imperfect; parallel to — Poo (noticed by
Vom Path on turnerite from Laacher See1). Parting is sometimes
developed parallel to oP and oo P. It is brittle with a conchoidal
to uneven fracture. The hardness is 5 to 5.5. The specific gravity
varies from 4.64 to 5.3. The luster is resinous to waxy. The crystal
faces are splendent in fresh, pnre specimens; dull in weathered, im-
pure specimens. The color is honey yellow, yellowish brown, amber
brown, reddish brown, brown or greenish yellow. Derby2 describes
specimens of lusterless, whitish grains in muscovite granite of Sao
Paulo, Brazil, which he proved to be cerium phosphate.
iPoggendorff, Annalen, 1871, Erg.-Bd. 5, p. 413; Sitzungsber. Bayer. Akad. Wiss. 1870, vol-
2, p. 271.
2Am. Jour. Sci. (3), vol. 37, 1889, pp. 109-114.
IN NORTH CAROLINA.
13
The monazitoid of Hermann is of a dark-brown color, due to
impurities. In weathered specimens of impure monazite the sur-
face is rough, dull, and sometimes covered with a light-brown earthy
substance.
The purest specimens of mon azite are transparent, becoming trans-
lucent and even totally opaque in the impure varieties.
It is frequently difficult to distinguish monazite, in fine grains,
from certain other minerals by the uninitiated eye. Some varieties
of yellowish-brown quartz are quite easily confounded with mona-
zite; so also, at times, sphene, zircon, epidote, corundum, etc. For
the benefit of the unscientific prospector it may be stated that the
chief macroscopic distinctions are those of color, hardness, and speci-
fic gravity. The color is usually yellowish, inclined to reddish,
brownish, or more rarely greenish tints. The fresh unaltered grains
are transparent or translucent. The larger crystals are frequently
dull in luster and opaque.
The hardness is from 5 to 5.5, between that of apatite and ortho-
clase (feldspar). Thus it can be scratched by a fragment of ordi-
nary feldspar, (hardness 6) or quartz (hardness 7). The hardness of
sphene is 5 to 5.5, of zircon T.5, of epidote 6 to 7, of corundum 9.
The specific gravity of monazite is 4.64 to 5.3; that of quartz is only
2.6, of sphene 3.5, of zircon 4.7, of epidote 3.25 to 3.5, of corundum
3.95 to 4.10.
OPTICAL CRYSTALLOGRAPHY.
Thin sections, by transmitted light, are colorless to yellowish.
Pleochroism is generally scarcely noticeable. Absorption b > C = a.
The plane of the optic axes is perpendicular to the plane of sym-
metry qo P"oo. The positive acute bisectrix lies in the obtuse angle
/?; hence sections parallel to oP show the full interference figure.
Optical measurements of monazite.
b=h
c Ac=l
04
3 00
3 46
5 54
Localities.
(Turnerite) Tavetsch, Switzerland
Arendai, Norway
Norwich, Connecticut
Schiittenhofen, Bohemia
Measured by
Trechmann.
Wiilfing.
Des Cloizeaux.
Scharizer.
I
n
MONAZITE, AND MONAZITE DEPOSITS
The opitcal angle is small; various measurements give:
Optical measurements of monazite.
2 E(red)
2E(yel-
low).
2E(vio-
let).
2V
(red).
2 V (yel-
low).
Disper-
sion.
Localities, etc.
o /
29 04
o /
o /
28 48
31 43 \
o /
o /
p>v
p<y
P>v
Norwich, Conn., Des Cloi-
zeaux.
Sibera, Des Cloizeaux.
31 08i
25 22
24 56
28 25
12 44
14 29
Schuttenhof en, Bohemia,
Scharizer.
Pisek, Bohemia, Vrba.
29 07
14 50
34 12
p<v
Turnerite, Tavetsch,
Trechmann.
The dispersion is weak and horizontal. The single refraction ii
high; double refraction considerable.
Optical measurements.
a
P
7
y—a
y-13
(3 — a
Localities, etc.
1.9285
1.9465
1.7965
\
Schiittenhofen, Bohe-
1.7957
1.8411
0.0454
0.0446
0.0008
mia, Scharizer.
Arendal, ISTorway, E.
Wiilfing.
CHEMICAL COMPOSITION.
COMPOSITION AND ANALYSES.
The earlier discoverers had very little knowledge of the true
chemical composition of monazite. Breithaupt,1 in 1829, concluded
from the high specific gravity of the Siberian monazite that it was
a metallic oxide or acid in combination with some of the earths.
Shepard2 stated in 1835 that monazite was inferred to consist of
the oxide of uranium with some one or more of the earths (accord-
ing to blowpipe tests of Breithaupt). At the same time turnerite,
according to blowpipe experiments of Mr. Children, was supposed
to contain chiefly A1203, CaO, MgO, and a little iron, with traces
of Si02. In 1837 Shepard published an analysis of his edwardsite (see
table, anal. No. 29, p. 19), in which he first pointed out the existence
of cerium. He deduced the relationship P205: CeO=l: 1 J, making
^chweigger— Seidel, vol. 55, 1829.
-Treatise on Mineralogy, 1st edition; vol. 2, 1835.
IN NORTH CAROLINA. 15
the mineral a basic sesqui-phosphate of cerium protoxide. He also
found 7.77 per cent Zr02, but it is doubtful whether this is an origi-
nal constituent; more probably it may be referred to the presence
of the mineral zircon as an impurity in the sample, which is an
almost constant accompaniment of monazite. He found further,
A1203, Si02, FeO, MgO, and a trace of glucina.
Kersten,1 in 1839, analyzed the specimens from the Ural Moun-
tains, previously determined by Breithaupt to be a combination of
uranium oxide with some of the earths, but found no trace of uran-
ium. He did find it to be essentially a phosphate of cerium and
lanthanum oxides, and was the first to show the presence of La203,
Th02, Sn02, MnO, CaO, and traces of Ti02, and K20. (See table,
anal. No. 20, p. 18.)
In 1846 Woehler2 published an analysis of cryptolite from Aren-
dal, Norway, determining it to be a phosphate of cerium oxide.
(See table, anal. No. 21, p. 18.) He could find neither Zr02 nor Th02,
from which he concluded that the absence of Th02 distinguished
cryptolite from monazite and ed ward site.
In 1847 Hermann3 came to the conclusion that monazite was the
neutral phosphate of cerium, in which a large part of the cerium
was replaced by lanthanum and a small part by CaO, MgO, and
MnO in the varieties of lighter specific gravity, while the heavier
varieties (sp. gr. 5.281) contained less P205, and a large part of the
stannic acid was replaced by tantalic acid (Ta205). (See table,
anal. No. 17, p. 1 8.) This variety he called monazitoid, which occurs
at Lake Ilmen, near Miask, Siberia. It is of a dark-brown color as dis-
tinguished from the lighter color of monazite. At first Hermann
denied the presence of thoria in monazite and monazitoid, but later
he found as high as 32.44 per cent Th02 in a specimen5. (See table,
anal. No. 19, p. 1 8.) Monazite and monazitoid, he says, have the same
form, and are therefore heteromeric, having different composition.
Like all heteromeric minerals they show a tendency to mix, and thus
give a series with slight difference in specific gravity. Koksharow4
believed that monazitoid was simply an impure variety of monazite,
iPoggendorff, Annalen, vol. 47, 1839, p. 385.
2Poggendorff, Annalen, vol. 67, 1846, p. 424.
3Jour. prakt. Chemie, vol. 40. 1847, p. 21.
4Materialien zur Mineralojiie Russlauds, vol. 4, 1892, pp. 7-34.
5It is highly probable that the greater part of this w as lanthanum.
/
16 MONAZITE, AND MONAZITE DEPOSITS
where the tantalic acid was derived from columbite and samarskite,
in which the crystals of monazitoid were intergrown, and this
appears most probable. Blomstrand1, in his analysis of specimens
from the Ilmen Mountains (same locality as Hermann's monazitoid),
found 16.64 per cent Th02, but no tantalic acid. (See table, anal.
No. 15, p. 18.)
In 1850 Watts2 published an analysis of his phosphocerite, which
he determined to be a phosphate of cerium protoxide, including
lanthanum and didymium.
Websky,3 in 1865, in making blowpipe tests on monazite from
the Riesengebirge, found cerium, phosphoric acid, and titanic iron;
the latter, however, must have been an impurity in the powder,
probably from the ilmenite, which is mentioned as occurring as an
associated mineral in this locality.
Radominsky's variety of monazite, kararfveite, from Sweden, was
found by him to contaiu 4.33 per cent fluorine4. (See table, anal. No.
16, p. 18.) Blomstrand's analysis of a specimen from the same local-
ity showed only 0.33 per cent fluorine. (See table, anal. No. 11,
p. IT,) and he concluded that the so-called kararfveite was simply an
impure variety of monazite.
Scharizer5 first pointed out, in 1887, the presence of an element
of the erbium group in the monazite from Schiittenhofen, Bohemia.
His determination was made on a thin section by means of a spec-
troscopic attachment to the microscope.
Genth,6 in 1889, published an analysis of monazite from the Yille-
neuve mica mine in Canada, in which he determined 4.76 per cent
of (Y, Er)2 03. (See table, analysis No. 37, p 20.)
Blomstrand,7 in 1889, also showed the presence of yttrium in the
monazite from southern Norway; and he first pointed out here the
presence of lead oxide.
Below is given a table containing a number of analyses of mona-
zite from various localities, with references:
iZeltschr. fur Kryst., vol. 20, 1892, p. 367.
2Quart. Jour. Chem. Soc. London, vol. 2, U-50, p. 131.
-Zeitsehr, Deutsch geol. Gesell., Berlin, vol. 17, 18<>5, p. 567.
*Compte Rendu, vol. 78, 1874, p 764.
5Zeitschr. liir Krvst, vol. 12, 1887. p. 255.
GAm. Jour. Sci., vol. 38, 188'.*, p. 203; Zeitschr, fur Kryst., vol. 19. 1891, p. 88.
7Zeitschr. fur Kryst., vol. 15, 1889, p. 99; Geol. FSreningens, Forhandl., Stockholm, vol. 9,
1887, p. 160.
IN NORTH CAROLINA.
17
CO
o
<
CO
<^>
co
CO
T-H
OS CO OC
lO CD Tj
CO OS cc
CO CO <N
2.54
10.39
2.16
JO
00
00
T—
cc
03
JO
tH
T-l
25.56
37.92
20.76
MHQOrt
xco-^tjj
00 CO
CO
CO
tH
co ^ oo
tH CO CO
lO
CO
T-H
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1
IN NORTH CAROLINA.
21
Below are given the thoria contents of a number of samples
from North Carolina, which were analyzed for the writer by Dr.
Charles Baskerville, assistant chemist of the North Carolina geo-
logical survey. These analyses are not made on the pure mineral,
but on the commercial monazite sand, which contains up to about
67 per cent, monazite, the remainder being quartz, garnet, zircon,
and other accessory minerals.
Thoria contents of North Carolina monazite sand.
[Per cent.]
1
2
3
4
5
6
7
8
9
Th02
0.175
0.225
2.15
2.25
0.40
6.54
0.125
0.29
2.48
Th02.
10
0.26
11
1.27
12
6.30
13
14
5.19 5.87
15
6.26
16
1.75
17
18
1.93 3.40
1. Bennett's Mill, Silver Creek, Burke Coun-
ty.
2. Northeast side Brindle Ridge, Burke
County.
3. White Bank gold mine, Burke County.
4. Ball's Creek, at Morganton road cross-
ing, Burke County.
5. Bailey's Creek, 3 miles southwest of Glen
Alpine Station, Burke County.
6. Linebacher place, Silver Creek, Burke
County.
7. Mac Lewrath place, Silver Creek, Burke
County.
8. East fork of Satterfield Creek, Burke
County.
9. Mac Lewrath Branch, McDowell County.
10. Bracket- town, South Muddy Creek, Mc-
Dowell County.
11. Long Branch, McDowell County.
12. Alexander Branch, McDowell County.
13. Daniel Peeler's farm near Bellwood,
Cleveland County.
14. Proctor's farm, near Bellwood, Cleve-
land County.
15. Wade McCurd's farm, Carpenter's Knob,
Cleveland County.
16. Tailings from No. 15.
Henrietta, Rutherford County.
18. Fallston, Cleveland County.
METHOD OF ANALYSIS OF MONAZITE SAND.
The method of analysis employed by Dr. Baskerville is given
below in his own words1. He claims only " approximate results,
and absolute accuracy cannot be vouched for." It is substantially
the same as Prof. S. L. Penfleld's method2 with a few modifica-
tions.
The pulverized sand, 2 grams, is weighed into a small flask
holding about 100 c. c; 10 c. c. H2S04 (1 :1) are added, and the
whole cooked on a sand bath with frequent agitation, until the
rFrom a letter to the writer, March, 1895.
2Am. Jour. Sci. (3), vol. 24, 1882, p. 253.
/
22 MONAZITE, AND MONAZITE DEPOSITS
acid becomes concentrated and fumes arise. A small funnel is
used in the neck of the flask to prevent loss by spitting and bub-
bling. It is allowed to cool, and if not completely decomposed, a
fresh amount of H2S04 is added, and the previous operation
repeated. Add a little water, keeping the temperature down as
well as possible. The insoluble silicates are removed by filtering
and washing with cold water. The clear filtrate is diluted to 400
or 500 c. c, and an excess of oxalic acid added, whereby the
oxalates of the cerium metals and thorium are precipitated.
This is done in the hot solution, allowing the same to boil a few
moments after adding the oxalic acid. It is then allowed to
remain in the cold for twelve hours, when it is filtered and washed
with cold water.
The precipitated oxalates are ignited by heating slightly above
faint redness. After all the carbon is burned off, the contents of
the crucible are turned into a platinum or porcelain dish, washing
the crucible with H2S04 (1 :1). On heating, the oxides are usu-
ally dissolved completely; the excess of H2S04 is gotten rid of by
gentle heat. To accomplish this, the disk is placed on a triangle
inside of an iron dish to which the lamp flame is applied. The
sulphates, which are almost invariably colored red, yellow or
orange, are dissolved in water. The whole mass is usually com-
pletely soluble in about 15 c. c. H20, but on further dilution a
precipitate is formed. The solution is made up to 200 or 300 c. c,
i. e., sufficient water is added to hold all the thorium sulphate in
solution; it is then boiled and filtered. If the filtrate is acid, it
is neutralized with NH4OH, and the thorium is precipitated out
by means of Na2S203. The filtered precipitate is burned to Th02
and weighed as such in a platinum crucible.
CHEMICAL AND BLOWPIPE REACTIONS.
Monazite is with difficulty and incompletely soluble in hydro-
chloric acid. It is attacked completely by sulphuric acid, and by
potassium acid sulphate. It is infusible before the blowpipe flame,
turning gray. When moistend with H2S04 it colors the flame
bluish green (phosphorus reaction). The borax and salt of phos-
phorus beads are yellowish when hot, and colorless on cooling;
IN NORTH CAROLINA. 23
the saturated borax bead becomes enamel white on naming. Fused
with soda, the mass treated with water and filtered, the residue
dissolved in a little HC1, the solution gives with oxalic acid a pre-
cipitate, which on ignition becomes brick red (cerium oxide).
With soda on charcoal a little tin is sometimes obtained.
MICHRO-CHEMICAL
For cerium. — The dilute solutions of cerium sulphate or chlo-
ride give, with oxalic acid or ammonium oxalate, a precipitate,
which is at first flocculent but soon becomes crystalline, being
composed of fine, doubly terminated, often forked and serrated
prisms; in more concentrated solutions these form themselves into
radial groups. The little crystals have an oblique extinction and
a high double refraction. In hot, very dilute solutions thin
rhomboidal plates are precipitated, whose acute angle is about 86°;
they have a tendency to form rectangular intergrowths, and appear
to be monoclinic.
For phosphorus. — Phosphoric acid is precipitated in a solution
of the sulphate by the addition of ammonium molybdate, which
on drying gives little crystals resembling rhombic dodecahedrons,
yellow in reflected and greenish in transmitted light.
Derby 2 has found that these micro-chemical tests are the best
means of identifying monazite.
SPECTROSCOPIC TESTS.
Scharizer3 tested the absorption spectrum of a basal cleavage
plate of the Shiittenhofen monazite by replacing the ocular of the
microscope with a spectroscope a vision direct e. The illumination
was obtained by the reflection of direct sunlight from a concave
mirror. The spectrum showed a broad absorption band in the
yellow between the Fraunhofer lines C and D, corresponding to
didymium, and a less broad one at the end of the green near the
line F, corresponding to erbium.
1H. Rosenbusch, Mikroscopische Physiograhie, Vol. T., 3d ed., 1892, p. 266.
2Am. Jour. Sci. 3, vol. 37, 1889, pp. 109 114. Zeitschr. fur Kryst., vol. 19, 1891, p. 78.
3Zeitscnr. fiir Kryst., vol. 12, 1887, p. 264.
24 MONAZITE, AND MONAZITE DEPOSITS
CHEMICAL MOLECULAR CONSTITUTION OF MONAZITE.
Penneld,1 in his analyses of Connecticut, North Carolina, and Vir-
ginia monazite (see anal. Nos. 30, 31, 32, 33; p. 20), deduces the
relation
(Ce, La, Di) 203: P205=1 : 1
Th02: Si02 =1 : 1
The former corresponds to the normal phosphate of the cerium
metals (R2P203) ; the latter corresponds to that of normal thorium
silicate, which, in combination with a small percentage of water,
makes the mineral thorite or orangite (ThSio^H20). He concludes,
then, that monazite is essentially a normal phosphate of the cerium
metals, in which thorium silicate is present in varying proportions
as an impurity in the form of the mineral thorite or orangite.
Dunnington2 had somewhat previously come to the same conclu-
sion.
Rammelsberg's3 formula of thorium-free monazite from Arendal,
Norway, was R2P2Og=(Ce, La, Di) 2P208, thus agreeing with Pen-
field.
Blomstrand,4 from his analyses of Norwegian and Siberian mona-
zite (see anal. No. 1-10, 13-15, pp. 17, 18), concludes that the mineral
is a normal tribasic phosphate, an excess of bases being combined
with Si02. Thus : m (3RO,P205)+2EO, Si02+pH20, where m=5
to 20, and p=less than 1 usually.
He does not believe, as Penneld does, that the thoria is origi-
nally combined with silicia as thorite, but that it is a primary con-
stituent, present as the phosphate, either in combination with the
cerium or as an isomorphous mixture, thus :
IV III || IY
Ce. Ce (03PO)2 and ETh (03PO)2 ;
and that it is altered to the silicate by siliceous waters.
iAm. Jour. Sci. (3), vol. 24, 1882, p. 250; vol. 36, 1888, p. 322. Zeitschr. fur Kryst.. vol. 7, 1SS3.
p. 366; vol. 17, 1890, p. 407.
2Am. Cuem. Jour., vol. 4, 1882, p. 138.
3Zeitsclir. Deutsch. geol., Gesell. Berlin, vol. 29, 1877, p. 79. Zeitschr. fur Kryst., vol. 3.
1879, p. 101.
^Zeitschr. fur Kryst., vol. 9, 1887, p. 160; vol. 20, 1892, p. 367.
IN N0KTH CAEOLINA.
25
Rammelsberg1 has explained the analyses of Kersten and Her-
mann (see anal. Nos. 19, 20, p. 18), respectively, by the formulae :
j 5 R3P2OM , j 3K3F08)
I Th2 P2 O9 j ana ( Th3 P4 O10 j
which does not, however, appear to express a constant molecular
constitution.
ARTIFICIAL PRODUCTION OF MONAZITE.
In 1875 Radominsky2 produced monazite artificially by treat-
ing a solution of impure cerium salt with sodium phosphate, add-
ing an excess of chloride of cerium, and heating to redness. After
cooling and crystallization, long yellow prisms with striated sur-
faces were formed. The specific gravity was 5.09, and the com-
pound, by analysis, was found to agree in composition with that
of the mineral monazite.
GEOLOGICAL AND GEOGRAPHICAL OCCURRENCE.
The following table presents the salient features of the geograph-
ical, geological, and mineralogical occurrences of monazite. All
known localities at which the mineral monazite and its equiva-
lents, turnerite, cryptolite, etc., have been found up to the present
time are tabulated here. It is placed at the beginning of this
chapter as a general introduction, and for the purpose of conveni-
ent reference, to what is to follow.
Conditions of occurrence of monazite.
Localities.
Country Rocks.
Associated Minerals.
UNITED STATES.
East Blue Fill, Me
Wakefield, N H ..
do
Westerly, R. I
do
Westford, Mass
Gneiss
do
Xenotime.
do
Chester, Conn
do
do
Watertown, Conn
dnalbite) Apatite, zircon,
Portland, Conn
tourmaline.
Yorktown, N. Y
Sillimanite.
Xenotime.
Microlite, araazouit e,
New Speedway, along Harlem river, New-
York City
beryl, apatite, orthite,
columbite, manganese
tantalate.
^andbuch der mineral. Cliemie. 1875, p. 305.
2Comptes Rendus, vol. 80, 1875, p. 305.
26
MONAZITE, AND MONAZITE DEPOSITS
Localities.
Associated Minerals.
united states.— Continued.
Deake mica mine, Mitchell county, N. C.
Ray mica mine, Yancey county, N. C.
Mars Hill, Madison county, N. C
Boomer, Wilkes county, N. C
Autunite, uraninite, gum-
mite, garnet.
(In orthoclase.) Beryl,
garnet.
Quartz, garnet, zircon,
rutile, magnetite, ilmen-
ite.
Rutile.
In quartz.
Quartz, garnet, zircon,
rutile, brookite, xeno-
time, f ergusonite. corun-
dum, epidote, beryl, cy-
anite, magnetite, pyrite,
menaccanite.
Crowders Mountain, Gaston county, N. C
Todd's Branch, Mecklenburg county, Gold placers I Garnet, zircon, diamond. .
N.C
Spartanburg and Greenville counties, S. C
Milholland's Mill, Alexander county,
N. C
Emerald and hid denite mine, Alexander
county, N. C
Burke, Rutherford, Cleveland, Polk, Ca-
tawba, and Lincoln counties, N. C
"The Glades,11 Hall county, Ga
CANADA.
Villeneuve mica mine, Ottawa county.
Quebec
SOUTH AMERICA.
Rio Chico, Antioquia, United States of
Columbia
Alcobaca, Province of Bahia, Brazil
Oaravellas, Province of Bahia, Brazil
Salabro, Province of Bahia, Brazil
Gneiss, and stream (Same as Burke, etc. coun-
placers ties, N. C.)
Gold placers Quartz, rutile, garnet, etc.
Pegmatite.
Garnet, tourmaline, uran-
inite.
Province of Minas Geraes.
Province of Minas Graes, Rio de Janeiro
and Sao Palo, Brazil.
Provinces of Bahia, Minas Geraes, Rio de Porphyritic
Gold placers
Beach sands
do
Diamond sands Quartz, zircon, garnet, dls-
j thene, staurolite. corun-
dum,
do Magnetite, ilmenite. py-
rite.
Gold placers
Janeiro, and Sao Palo, Brazil.
Buenos Ayres, Argentine Republic.
Cordoba, Argentine Republic.
Corn wall -
Holma
Kararfvet
Johannisberg.
NORWAY.
Dillingso, Moss, Lonnesby, Arendal, Nar
estoe, Hitteroe, Hvalo
Arendal and Midbo
Notero
Helle
Ivalo
FINNISH LAPMARK.
granu Apatite, magnetite, imien-
litic, and schistose
gneisses, red syen-
ite, granite dikes... I
River sands Zircon
Gneiss and granite...
ite, rutile, garnet, zircon,
Sillimanite.
Clay slates
Albitic granite.
Cobalt ore
Pegmatite
Granite
Gold sands.
Quartz, albite.
Gadolinite, hjelmite. em-
erald.
Cryptolite in apatite.
In feldspar, enveloped by
orthite.
Zircon.
1
IN NORTH CAROLINA.
27
Localities.
Country Rocks.
Associated Minerals.
RUSSIA.
Albitic granite
Placers
skite.
BELGIUM.
Nil St. Vincent
FRANCE.
Le Puys, near St. Christophe, Dauphine...
SWITZERLAND.
sphene, anatase.
Quartz vein, tra-
versing mica
schist.
Rutile.
Tessin
Perdatsch
Santa Brigritta, near Ruaras, Tavetsch
Valley.
GERMANY.
Laacher See, near Coblentz
Druse in sanadine
bomb.
Pegmatite
AUSTRIA.
Josephinenhuette, Riesengebirge, Silesia
(In black mica.) Ilmenite,
f ergusonite, yttrium
spar, zircon.
Gadolinite, yttrium -spar,
xenotime, f ergusonite.
Apatite.
In beryl and feldspar.
Schuttenhofen, Bohemia
Pegmatite
Pisek, Bohemia
AUSTRALIA.
Vegetable Creek, County Gough, New
South Wales.
Monazite is an accessory constituent of the granite eruptives and
their derived gneisses. It has been found in these rocks over
widely separated areas of the earth's surface, and further search
and study is liable to reveal its probable universal presence, in
varying proportions, in most granites and granite gneisses. Thus
Derby1 has found monazite as a constant accessory constituent in
the porphyritic, granulitic, and schistose gneisses of the provinces
of Bahia, Minas Geraes, Rio de Janeiro, and Sao Palo, in Brazil,
representing 300 miles along the axis of the great gneiss region of
the Maritime Mountains. The granite dikes, intersecting the
gneiss, also carry monazite.
The gneisses of the South Mountain region in North Carolina,
covering an area of some 2,000 square miles, in Burke, McDowell,
!Am. Jour. Sci., vol. 37, 1889, pp. 109-114.
/
28 MONAZITE, AND MONAZITE DEPOSITS
Rutherford, Cleveland, Polk, Catawba, Lincoln, and Gaston coun-
ties, and extending into Spartanburg and Greenville counties, S.
C, have been shown to contain monazite.1 I have since identified
the mineral in the thin sections of several specimens of mica gneiss
collected in that locality. The rocks are granitic mica gneisses,
hornblende gneisses, which approach more nearly to diorite gneisses,
and pegmatites. (See map. Plate II.)
Monazite has recently been found in Hall county, Georgia, near
"The Glades," a post-office about 10 miles northeast of Gainesville,
on the north side of the Chattahoochee river. It occurs in the
gold placers of Flat creek and its tributaries, the Glade, Stocke-
neter, Hamilton and Huram branches.
Derby,2 by examining the heavy residues of a number of hand
specimens, selected at random from the collection in the National
Museum, of Washington, D. C, described the occurrence of mon-
azite in certain granites and gneisses of Maine, New Hampshire,
Rhode Island, and Massachusetts.
The monazite of Chester, Portland, and Watertown, Conn., is
an accessory constituent of the granite and gneisses. In Amelia
county, Ya., it is found in albitic granite ; also in the Ilmen Moun
tains of Russia.
The pegmatites of southern Norway, Silesia, and Bohemia, and
of some of the mica mines in Canada and North Carolina, also
contain monazite.
Derby (in paper above cited) has found monazite in a red syenite
at Serra do Stauba, in the province of Bahia, Brazil. The basic
eruptives (diabase, quartz-diorite, mica-diorite, and minette) thus
far examined by him in Brazil showed no traces of monazite.
The turnerite of the Laacher See (which is an extinct volcanic
crater), near Coblentz, in Prussia, was found in a druse of a sana-
dine bomb, the only known occurrence of monazite in an undoubted
volcanic rock.3 It was grown into and upon a crystal of orthite.
The turnerite of Olivone, Switzerland, occurs in a quartz vein,
20 to 30 cm. thick, traversing crystalline schists.4 The percentage
aTrans. Am. Inst. Min. Engr., Mar., 1895.
2Proc. Rochester, Acad. Sci., vol. 1, 1891, pp. 294-206.
3G. von Rath., Poggendorff, Annalen, 1871, Erg.-Bd., 5, p. 413.
*G. Sellgman, Zeitschr. fur Kryst., vol. 9, 1884, p. 420.
•
I
IN NORTH CAROLINA. 29
of monazite in these rocks is exceedingly small, often infinitesimal;
thus Derby (in paper above cited) states that the granite dikes in
the gneiss of Serra de Tingua, near Rio, are rich in the yellow
mineral, carrying 0.02 to 0.03 per cent, and a fine-grained granite
dike on the outskirts of Rio de Janeiro showed 0.07 per cent mon-
azite.
The cryptolite of Norway occurs as inclusions of very fine, needle-
shaped crystals in apatite.
While making a reconnaisance trip through the North Carolina
region, the writer, in company with Messrs. H. A. J. Wilkens, E.
M., and Jno. R. Kirksey, discovered on June 19th, 1895, the inter-
esting, and so far as known new, occurrence of monazite in cyanite.
The locality where first observed was at the Peeler and Ivester
placers on a branch of Knob creek, about 16 miles north of Shelby
in Cleveland county, N. C. Numerous fragments of a light blue
grey cyanite, usually less than one inch, but occasionally as large
as three inches in longest dimension, were found in the tailing
dumps from the bottom gravels that had been washed in the sluice
boxes. The fragments of pure cyanite contained intimately inter-
grow a crystals of mcnazite, the latter constituting as much as 50
per cent of the mass at times, though some pieces of the cyanite
were practically barren. The bed rock and out cropping ledges
near here were carefully examined, in the hope of finding the orig-
inal source of this monazite-bearing cyanite, but without success.
It probably occurs in irregular nests and veinlets through the peg-
matitic mica gneiss, which forms the country rock.
Derby thinks (in paper above cited) that there is "a reasonable
probability that zircon, and to a less degree monazite, may prove
to be guide minerals by which eruptives and their derivatives can
be certainly identified, no matter what degree of alteration they
may have suffered."
Monazite has not been found in the sedimentary rocks, although
it may be present in some of these as a secondary mineral of trans-
portation.
The economically valuable deposits of monazite are found in the
placer sands of streams and rivers, and in the irregular sedi-
30 MONAZITE, AND MONAZITE DEPOSITS
mentary sand deposits of old stream beds and bottoms. Plates
I. and III. illustrate the occurrence of monazite sands along the
upper reaches of a small branch. The decomposition and disintegra-
tion of the crystalline rocks, the original source of the mineral, has
proceeded to considerable depths, particularly in the southern,
unglaciated countries. By erosion and secular movement the
material is deposited in the stream beds and there undergoes a nat-
ural process of sorting and concentration, the heavy minerals being
deposited first and together. The richer portions of these stream
deposits are thus found near the head waters. Such deposits have
been described from ISorth and South Carolina in the United States,
from Brazil, and from the Sanarka river in Russia.
The beach sand deposits along the coast of Brazil, in the province
of Bahia, have a similar explanation, the concentration there being
brought about by the action of the waves.
ACCESSORY MINERALS.
The main constituent of the granitic rocks (quartz, feldspar, and
mica) all contain the monazite as intergrowths, though it appears
to be more generally confined to the feldspar.
Zircon may be regarded as a constant associate; in fact, it is
even a more important and general accessory constituent of the
rocks than monazite. Among the other usual associated minerals,
of coeval origin with the monazite, are xenotime, fergusonite,
sphene, rutile, brookite, ilmenite, cassiterite, magnetite, and apa-
tite; sometimes beryl, tourmaline, cyanite, corundum, columbite,
samarskite, uraninite, gummite, autunite, gadolinite, hjelmite, and
orthite.
The association of monazite with orthite, gadolinite, samarskite;
uraninite, and hjelmite is interesting as suggesting the possibility
of some genetic relationship.
Among the principal secondary and metamorphic minerals found
in association with monazite are rutile, brookite, anatase, epidote,
orthite, garnet, sillimanite, and staurolite.
ECONOMIC USE.
The economic value of monazite lies in the incandescent proper-
1
£ o
\
IN NORTH CAROLINA. 31
ties of the oxides of the rare earths — cerium, lanthanum, didymium-
and thorium — which it contains. These are utilized, principally
the thoria, together with limited quantities of the lanthanum and
didymium, in the manufacture of the Welsbach and other incan-
descent gaslights. The cerium goes to the drug trade as the oxa-
late.
The Welsbach light consists of a cylindrical hood or mantle com-
posed of a fibrous network of the rare earths, the top of which is
drawn together and held by a loop of platinum wire. It is perma-
nently suspended over the flame of a specially-devised burner, con-
structed on the principles of the Bunsen burner, in which the gas
is burned with the access of air, thus utilizing the heating and not
the illuminating power of the hydrocarbons. The mantle becomes
incandescent, glowing with a brilliant and uniform light.
The method of manufacturing this mantle is in brief as follows :
A cylindrical network, about 1J inches in diameter, is woven out
of the best and strongest cotton thread. This is first washed in
ammonia and then in warm water, being wrung out in a mechani-
cal clothes wringer each time. It is then soaked in a solution of
the rare earths and dried in a revolving hot-air bath. After being
cut to the proper lengths, each cylinder is shaped over a wooden
form, and the upper end is drawn together by a loop of platinum
wire. The cotton fiber is then burned off under the flame of a
Bunsen lamp, which leaves a network of the rare oxides exactly
resembling the original woven cylinder, each fiber being identically
preserved, excepting that the size is somewhat reduced by shrink-
age. After a series of tempering and testing heats of various
intensities the mantle is ready for use. The exact composition of
the solution of the rare earths is not known, being one of the trade
secrets; but it is a well known fact that monazite rich in thoria is
sought after, and the natural inference is that this element consti-
tutes one of the most important ingredients.
METHODS OF EXTRACTION AND CONCENTRATION.
The commercially economical deposits of monazite are those
occurring in the placer sands of the streams and adjoining bottoms
and in the beach sands ah ng the seashore. The geographical
32 MONAZITE, AND MONAZITE DEPOSITS
areas over which such workable deposits have been found up to the
present time are quite limited in number and extent. In the
United States the placer deposits of North and South Carolina
stand alone. This area includes between 1600 and 2000 square
miles, situated in Burke, McDowell, Rutherford, Cleveland, and
Polk counties, ]N\ C, and the northern part of Spartanburg county,
S. C. The principal deposits of this region are found along the
waters of Silver, South Muddy, and North Muddy creeks, and
Henrys and Jacobs Forks of the Catawba river in McDowell and
Burke counties ; the Second Broad river in McDowell and Ruther-
ford counties ; and the First Broad river in Rutherford and Cleve-
land counties, IS". C, and Spartanburg county, S. C. These streams
have their sources in the South Mountains, an eastern outlier of the
Blue Ridge. The country rock is granitic biotite gneiss and dio-
ritic hornblende gneiss, intersected nearly at right angles to the
schistosity by a parallel system of small auriferous quartz veins,
striking about N. 70° E., and dipping steeply to the N.W. Most
of the stream deposits of this region have been worked for placer
gold. The existence of monazite in commercial quantities here
was first established by Mr. W. E. Hidden, in 1879. The thick-
ness of these stream gravel deposits is from 1 to 2 feet, and the width
of the mountain streams in which they occur is seldom over 12 feet.
The percentage of monazite in the original sand is very variable,
from an infinitesimal quantity up to 1 or 2 per cent. The deposits
are naturally richer near the head waters of the streams.
The monazite is won by washing the sand and gravel in sluice
boxes exactly after the manner that placer gold is worked. The
sluice boxes are about 8 feet long by 20 inches wide by 20 inches
deep. Two men work at a box, the one charging the gravel on
a perforated plate fixed in the upper end of the box, the other
one working the contents up and down with a gravel fork or
perforated shovel in order to float off the lighter sands. These
boxes are cleaned out at the end of the day's work, the washed
and concentrated monazite being collected and dried. Magne-
tite, if present, is eliminated from the dried sand by treatment with
a large hand magnet. Many of the heavy minerals, such as zir-
1
/
^™^^"^^^^™
m
j^jK.
*, " \ '
» ■■
i s
IN NORTH CAROLINA. 33
con, menaccanite, rutile, brookite, corundum, garnet, etc., can
not be completely eliminated. The commercially prepared sand,
therefore, after washing thoroughly and treating with a hand
magnet, is notpure monazite. A cleaned sand containing from 65
to 70 per cent, monazite is considered of good quality. From 20
to 35 pounds of cleaned monazite sand per hand, that is, from 40
to 70 pounds to the box, is considered a good day's work.
But very few regular mining operations are carried on in the
region. As a rule each farmer mines his own monazite deposit
and sells the product to local buyers, often at some country store
in exchange for merchandise.
At the present time the monazite in the stream beds has been
practically exhausted, with few exceptions, and the majority of
the workings are in the gravel deposits of the adjoining bottoms.
These deposits are mined by sinking pits about 8 feet square to
the bed rock and raising the gravel by hand labor to a sluice box
at the mouth of the pit. The overlay is thrown away excepting
in cases where it contains any sandy or gritty material. The pits
are carried forward in parrallel lines, separated by narrow belts
of tailing dumps, similar to the methods pursued in placer gold
mining. At the Blanton and Lattimore mines on Hickory
creek, 2 miles northeast of Shelby, Cleveland county, N. C, the
bottom is 300 to 400 feet wide, and has been partially worked
for a distance of one-fourth of a mile along the creek. The
overlay is from 3 to 4 feet, and the gravel bed from 1 to 3 feet
thick. (See Plate IV.)
The methods of mining and cleaning are much more systematic
in Spartanburg county, S. C, than in the North Carolina regions.
Although the raw material contains on an average fully as much
garnet, rutile, titanic iron ore, etc., as that in the North Caro-
lina mines, a much better finished product is obtained, and more
economically, by making several grades. Two boxs are used in
washing the gravel, one below the other. The gravel is charged
on a perforated plate at the head of the upper box, and the
clean-up from this box is so thoroughly washed as to give a high
grade sand, often up to 85 per cent. pure. The tailings discharge
■1
34 MONAZITE, AND MONAZITE DEPOSITS
directly into the lower box, where they are rewashed, giving a
second grade sand. At times the material passes through as
many as five washing treatments in the sluice boxes. Even
after these grades are obtained as clean as possible by washing,
the material, after being thoroughly dried, is further cleaned by
pouring from a cup, or a small spout in a bin, in a fine, steady
stream from a height of about 4 feet, on a level platform ; the
lighter quartz and black sand with the fine-grained monazite
(tailings) falls on the periphery of the conical pile and is con-
stantly brushed aside with hand brushes ; these tailings are
aftewards rewashed. Instead of pouring and brushing, the mate-
rial is sometimes treated in a winnowing machine similar to that
used in separating chaff from wheat.
Although the best grade of sand is as high as 85 per cent, pure,
its quantitative proportion is small as compared with the second
and other inferior grades, and there is always considerable loss
of monazite in the various tailings. It is impossible to conduct
this washing process without loss of monazite, and equally impos-
sible to make a perfect separation of the garnet, rutile, titanic
iron ore, etc., even in the best grades. The additional cost of
such rewashing and rehandling must also be taken into consider-
ation.
If the material washed contains gold, the same will be col-
lected with the monazite in concentrating. It may frequently
pay to separate it, which can easily be accomplished by treating
the whole mass over again in a riffle box with quicksilver.
It has been shown that the monazite occurs as an accessory
constituent of the country rock, and that the latter is decomposed
to considerable depths, sometimes as much as 100 feet. On
account of the minute percentage of monazite in the mother rock,
it is usually impracticable to economically work the same in
place, by such a process as hydraulicking and sluicing, for
instance. However, even hillside mining has been resorted to.
Such is the case at the Pheifer mine, in Cleveland county, N. C,
2 miles northeast of Shelby. (See Plate V.) The country rock
is a coarse mica (muscovite and biotite) gneiss, and the small
I F
IN NORTH CAROLINA.
35
monazite crystals may at times be distinctly seen, unaided by a
magnifying glass, in this rock. It is very little decomposed and
still quite hard, and the material that is mined for monazite is
the overlying soil and subsoil, which is from 4 to 6 feet thick.
This is loaded on wheelbarrows and transported to the sluice
boxes below the water race. The yield is fairly good, and the
product very clean, though the cost of working, of which, unfor-
tunately, figures could not be obtained, must be considerably in
excess of that of bottom mining. Where the rock contains
sufficient gold, as it somtimes does, to be operated as a gold
mine, there is no reason why the monazite can not be saved as
a valuable by-product.
OUTPUT AND VALUE OF MONAZITE IN THE UNITED STATES.
As the percentage of thoria is variable in different sands, the
value of the sand consequently varies in a measure also. It is
stated that the transparent greenish and yellowish brown varie-
ties are often rich in thoria, but this can not be depended on.
Hidden1 has suggested that the difference in cleavage may be
an indication of the presence or absence of thoria, that crystals
with the cleavage best developed parallel to oo Poo are the pure
phosphate of the cerium earths, free from thoria, while those in
which the cleavage is best developed parallel to OP, contain
thoria. But the cleavage is rarely observable in the rolled grains,
and if it were the above statement is by no means a proven fact.
He also makes the suggestion (in paper above cited) that the
density may'afford a test of the approximate comparative amount
of thoria present, and in support of this he mentions the follow-
ing examples :
Relation of thoria contents to density in monazite.
Specific
gravity.
Th02
Localities.
References.
5 30
5.20-5.25
Per cent.
14. 23
8.25
6.49
Amelia Coui't-House, Va
Portland, Conn
Table, p. 20, anal. No. 32.
Table, p. 20, anal. No. 30.
5.10
Burke County, N. C
Table, p. 20, anal. No. 31.
However, this will scarcely hold, for in other instances mona-
zite of the specific gravity 4.6-1 has been shown to contain
*Am. Jour. Sci., vol. 32, 1886, p. 207. Zeitschr. fur Kryst., vol. 12, 1887, p. 507.
36
MONAZITE, AND MONAZITE DEPOSITS
as much as 9.20 per cent, thoria (from Moss, Norway ; see p. 17.
anal. No. 4) ; and again, monazite of the specific gravity 5.19
contained but 3.18 per cent, thoria (from Dillingso, Norway : see
p. 17, anal. No. 2). On the whole, there is no method of
determining even the probable percentage of thoria, except-
ing by chemical analysis. Some monazite contains practically
no thoria. The best North Carolina sands (highest in thoria;
came from Burke and Cleveland counties. Some of the highest
grade sand from Brindletown, Burke county, runs from 4 to 6.60
per cent, thoria ; sand from Gum Branch, McDowell county, is
reported to run 3.30 per cent ; sand from the vicinity of Bell-
wood and Carpenter's Knob, in Cleveland county, runs from 5
to 6.30 per cent. The fluctuation of the thoria percentage is,
however, considerable even in the same locality. It also depends,
of course, in a measure on the degree of concentration of the
sand.
The price of North Carolina monazite has varied from 25 cents
per pound in 1887 to as low as 3 cents for inferior grades and 6
to 10 cents for the best grades in 1894 and 1895. It is only during
the past two years that the mining and concentration of monazite
sand in the South Mountain region has grown to a regular indus-
try, and it is at present progressing with increased vigor. In
1887 Mr. Hidden shipped from the Brindletown district, in Burke
county, N. C, 12 tons of monazite sand. And during 1888 and
1889 a number of tons (exact quantity unknown) were shipped
from North Carolina to the Welsbach Light Company in Phil-
adelphia. The product and value of the saud during 1893 and
1894 is given below. It was shipped in part to the AVelsbach
Light Company and in part to Europe (Germany and Austria).
Product and value of monazite in 1893 and 1894.
1893.
Value at
mines.
1891.
Value at
Quantity.
Price.
Quantity.
Price.
mines.
Pounds.
110,000
Cents.
6
5
$6,600
1,600
Pounds.
460,000
80,000
6,855
Cents.
$31,050
20,000
4,800
313
130,000
7,600
546,855
36,193
1
IN NORTH CAROLINA. 37
In Brazil considerable deposits of monazite occur in the beach
sands along the seashore. The largest of these is found in the
extreme southern part of the Province of Bahia, near the island
of Alcobaca. The surf as it breaks against the cliffs washes
away the lighter earths and minerals, leaving naturally concen-
trated deposits of monazite along the beach. Sacks filled with
this sand were shipped to New York in 1885, the deposit having
been taken for tin ore. Its true character was, however, soon
recognized, and since then a number of tons have been shipped
in the natural state, without any further concentration or treat-
ment, as ballast, mainly to the European markets. It is reported
to contain 3 to I per cent thoria. Very little exact information
concerning these Brazilian deposits is at present available. Mona-
zite has also been found in the gold and diamond placers of the
Provinces of Bahia (Salabro and Caravellas), Minas Geraes (Dia-
mantia), Bio de Janeiro and Sao Paulo. It has been found in the
river sands of Buenos Ayres, Argentine Republic, and also in the
gold placers of Bio Chico, at Antioquia, in the United States of
of Colombia.
In the Ural Mountains of Bussia monazite is found in the
Bakakui placers of the Sanarka Biver. The placer gold mines
of Siberia are reported to contain monazite.
Economic deposits of monazite are also reported to exist in the
pegmatite dikes of Southern Norway. It is picked by the miners
while sorting feldspar at the mines. It is not known to exist in
placer deposits. The annual output is stated to be not more than
one ton, which is shipped mainly to Germany.1
!U. S. Consular Report ; vol. 48, No. 179, Aug. 1895, p. 550.
/
38 MONAZITE, AND MONAZITE DEPOSITS
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IN NORTH CAROLINA. 39
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The Minerals of North Carolina : Bull. U. S. Geol. Survey No. 74, 1891,
pp. 77-78.
Goldschmidt (V.). Index der Krystallformen der Mineralien, vol. 2, 1890,
pp. 399-401 ; Zeitschr. fiir Kryst., vol. 10, 1885, p. 261.
Gorceix (M. H.). Die Mineralien der Diamantlagerstatten von Salabro,
Prov. Bahia: Zeitschr. fiir Kryst,, vol. 12, 1886, p. 639; Compt.
Rend., 1884, vol. 98, p. 1446; Bull. Soc. Min., 1884, vol. 7, p. 209.
Monazit von Caravellos, Brasilien : Zeitschr. fiir Kryst,, vol. 12, 1887, p.
643; Compt. Rend., 1885, vol. 100, p. 356; Bull. Soc. Min., 1885, vol.
8, p. 32.
40 MONAZITE, AND MONAZITE DEPOSITS
Groth (P.). Die Minerallagerstatten des Dauphine : Zeitschr. fiir Kyrst.,
vol. 13, 1888, p. 96; Sitzungsber, bayer. Akad. Wiss., 1885, pp. 371-
402.
Tabellarische Uebersicht der Mineralien, 3d ed., 1889, p. 72; Jour.
prakt. Chemie, vol. 33, p. 90.
Hermann (R.). Untersuchungen uber Zusanimensetzung des Monazits in
Beziehung auf den angeblichen Thonerde-Grehalt (Monazitoid) :
Jour, prakt. Chemie, vol. 40, 1847, p. 21 ; vol. 93, p. 109 ; Am. Jour.
Sci. (2), vol. 8, p. 125.
Heteromeres Krystall-System, 1860, p. 196.
Hessenberg (Fr.). Turnerit : Neues Jahrbuch, 1874, p. 826.
Hidden (W. E.). Notice on Occurrence of Monazite : Am. Jour. Sci. (3),
vol. 21, 1881, p. 159.
Notes of Mineral Localities : Am. Jour. Sci. (3), vol. 22, 1881/ p. 21 :
Zeitschr. fiir Kryst., vol. 6, 1882, p. 517.
Contributions to Mineralogy : Am. Jour. Sci. (3), vol. 32, 1886, p. 207 :
Zeitschr. fiir Kryst., vol. 12, 1887, p. 507.
Hoffman (G. C). Uraninite and Monazite from Canada : Am. Jour. Sci.
(3), vol. 34, 1887, p. 73; Zeitschr. fiir Kryst., vol. 15, 1889, p. 127.
Hussak (E.), Mineralogische Notizen aus Brasilien : Zeitschr. fiir Kryst..
vol. 24, 1895, p. 430.
Jeremejew (P. v.). Monazit-Krystalle aus dem Ilmengebirge : Zeitschr.
fiir Kryst., vol. 1, 1877, p. 398.
Kersten (C). Untersuchung des Monazits: Poggendorff, Annalen. vol.
47, 1839, p. 385.
Koenio (Gr. A.). Notes on Monazite : Proc. Acad. Nat. Sci. Philadelphia.
Jan. 24, 1882, p. 15; Zeitschr. fiir Kryst,, vol. 7, 1883, p. 423.
Koksharow (N. v.). Materialien zur Mineralogie Russlands, vol. 4, 1862.
pp. 7-34; vol. 6, 1870, pp.. 200 and 387; vol. 9, 1884, p. 10; vol. 10.
1884, p. 155.
Levy (A. Michel). Description of a New Mineral ; Ann. of Phil., London,
1823, vol. 5, p. 241.
Description d'une Collection des Mineraux, Paris, 1837, vol. 3, p. 423.
et Fouque (F.). Synthase des Mineraux et des Roches, Paris, 1882,
p. 253.
et Lacroix (Alf.). Les Mineraux des Roches, Paris, 1888, p. 242.
Liverside (A.). The Minerals of New South Wales, Sydney, 2d ed., 1882,
p. 137 ; Zeitschr. fiir Kryst., vol. 8, 1884, p. 87.
Mallard (M. Er.). Sur la Cryptolite de Norvege : Bull. Soc. Min., 1887,
vol. 10, p. 236.
1
IN NORTH CAROLINA. 41
Miers (H. A.). Ueber Connellit und Monazit von Cornwall : Min. Mag. &
Jour. Min. Soc. London, No. 30, Aug., 1885, vol. 6, p. 164; Zeitschr.
fiir Kryst., vol. 12, 1887, p. 181.
Fundort des Turnerit : Min. Mag. & Jour. Min. Soc. London, No. 39,
1889, vol. 8, p. 200 ; Zeitschr. fur Kryst., vol. 19, 1891, p. 415.
Naumann (C. F.) and Zirkel (F.). Eelemente der Mineralogie, Leipzig,
1885, p. 514 (cryptolite) ; p. 515 (monazite).
Nitze (H. B. C). North Carolina Monazite : Trans. Am. Inst. Min. Engr.,
Florida meeting, March, 1895.
Penfield (S. L.). On the Occurrence and Composition of Some American
Varieties of Monazite : Am. Jour. Sci. (3), vol. 24, 1882, p. 250 ;
Zeitschr. fiir Kryst., vol. 7, 1883, pp. 336-371.
and Sperry. Mineralogical Notes : Am. Jour. Sci. (3), vol. 36, 1888, p.
322; Zeitschr. fiir Kyrst., vol. 17, 1890, p. 407.
Pisani (F.) and Des Cloizeaux (A.). Turnerite von Luzerne : Zeitschr.
deutsch. geol. Gesell., Berlin, vol. 25, 1873, p. 568.
Chemische Untersuchung des Turnerit : Zeitschr. fiir Kryst., vol. 1,
1877, p. 405 ; Compt. Rend., vol. 84, p. 462.
Phillips (Wm.). Elementary treatise on Mineralogy, 5th American ed.,
Boston, 1844, p. 138 (turnerite) ; p. 422 (monazite).
Mineralogy, edited by H. J. Brooke and W. H. Miller, London, 1852, p.
493 (monazite) ; p. 494 (cryptolite) ; p. 653 (turnerite) ; p. 678 (mon-
azitoid).
Quenstedt (Fr. A.). Handbuch der Mineralogie, Tiibingen, 1877, p. 585.
Radominsky (F.). Sur un Phosphate de Cerium renfermant du Fluor:
Compt. Rend., vol. 78, 1874, p. 764.
Reproduction artificielle de la Monazite, et de la Xenotime : Compt.
Rend., vol. 80, 1875, p. 304.
Rammelsbero (C. F.). Handbuch der Mineral-Chemie, Leipzig, 1875, 2d
ed., pp. 304-305.
Erganzungs-Heft to 2d edition, Leipzig, 1886, pp. 168, 169.
Ueber Nephelin, Monacit, etc.: Zeitschr. deutsch. geol. Gessell., Berlin,
vol. 29, 1877, p. 79 ; Zeitschr. fiir Kryst., vol. 3, 1879, p. 101.
Renard (A.). Monazit von Nil St. Vincent: Zeitschr. fiir Kryst., vol. 6,
1882, p. 544.
Rice (W. N.). Minerals from Middletown, Conn.: Am. Jour. Sci. (3), vol.
29, 1885, p. 263 ; Zeitschr. fiir Kryst,, vol. 2, 1886, p. 300.
Richter (Th.). Plattner's Manual of Qualitative and Quantitative Anal-
ysis with the Blowpipe (transl. by H. B. Cornwall), 4th ed., New
York, 1880, pp. 200-203.
/
42 MONAZITE, AND MONAZITE DEPOSITS
Rose (G.). Reise nach dem Ural und Altai, Berlin, 1842, vol. 2, pp. 87 and
482.
Rose (GL). Ueber die Identitat des Edwardsit u. Monazit : Poggendorff.
Annalen, vol. 49, 1840, p. 223.
Rosenbusch (H.). Mikroscopische Petrographie der petrographisch wich-
tigen Mineralien, 3d ed., 1892, pp. 266 (cerium) and 498.
Seligmann (G.). Mineralogische Notizen : Zeitschr. fur Kryst., vol. 6,
1882, p. 231 ; Verhandl. d. naturh. Ver. Bonn, 1880, vol. 37, pp. 130,
131.
Mineralogische Beobachtungen : Zeitschr. Mr Kryst., vol. 9, 1884, p. 420.
Schartzer (R.). Der Monazit von Schiittenhofen : Zeitschr. Mr Kryst.
vol. 12, 1887, p. 255.
Shepard (C. U.). Treatise on Mineralogy, 1st ed., vol. 2, 1835, p. 53; 2d ed"
1844.
Description of Edwardsite, a new mineral : Am. Jour. Sci. (1), vol. 32,
1837, p. 162; Poggendorff, Annalen, vol. 43, 1838, p. 148.
Notice of Eremite, a new mineral species : Am. Jour. Sci. (1), vol. 32,
1837, p. 341.
Sperry (F. L.) and Penfield. Mineralogical Notes : Am. Jour. Sci. (3),
vol. 36, 1888, p. 322; Zeitsch. Mr Kryst., vol. 17, 1890, p. 407.
Trechmann (C. O.). Beitrage zur Kennthniss des Turnerit : Neues Jahr.
buch, 1876, p. 593.
Tschermak (G\). Lehrbuch der Mineralogie, Vienna, 1888, p. 535.
U. S. Consular Report, vol. 48, No. 176, May, 1895, p. 170. Uses of Monazite
in Europe.
vol. 48, No. 179, Aug., 1895, pp. 541-551. Monazite in Foreign Countries.
Vom Rath (G.). Mineralogische Mittheilungen : Poggendorff, Annalen,
vol. 119, 1863, p. 247; vol. 122, 1864, p. 407.
Uber ein neues Vorkommen von Monazit (Turnerit) vom Laachersee :
Sitzungsber. bayer. Akad. Wiss., 1870, vol. 2, p. 271; Poggendoff,
Annalen, Erg. Bd. 5, 1871, p. 413.
Notes on the Mineralogy of North Carolina : Am. Jour. Sci. (3), vol. 33,
1887, p. 160.
Ueber Beryll, Monazit, etc., von Alexander County, N. C. : Zeitschr.
Mr Kryst., vol. 13, 1888, p. 596; Sitzungsber. nied. Ges. Bonn, 1866,
pp. 67, 68, 149, 254.
Watts (H.). On Phosphocerite, a new mineral containing phosphate of
cerium : Quart. Jour. Chem. Soc, London, 1850, vol. 2, p. 131.
Websky. Monazit von Schreiberhau : Zeitschr. deutsch. geol. Gesell..
Berlin, vol. 17, 1865, p. 567.
1
IN NORTH CAROLINA. 43
Wohier {¥.). Ueber den Kryptolith : Poggendorff Annalen, vol. 67, 1846,
p. 424.
Zirkel (F.) and Naumann (C. F.). Elemente der Mineralogie, Leipzig,
1885, p. 514 (kryptolith); p. 515 (monazit).
Lehrbuch der Petrographie, 1893, vol. 1, p. 432.
Zschau (E.). Fifth Supplement to Dana's Mineralogy, Am. Jour. Sci. (2)
vol. 25, 1858, p. 410.
/
INDEX.
Page.
Analyses of monazite 17-20
Analysis, method of 21, 22
Angular measurements of monazite 13
Argentine Republic, monazite in 26, 37
Artificial production of monazite 25
Associated minerals of monazite 25-27, 30
Australia, monazite in 27
Austria, monazite in 27
Axial ratios of monazite 12
Baskerville, C, cited 21
Belgium, monazite in 27
Bibliography 38-43
Blanton mine, N. C 33
Blomstrand, C. W., cited 10, 16, 17, 18, 24
Blowpipe reactions of monazite 22-23
Brazil, monazite in 26, 27, 30, 37
Breithaupt, A., cited 8,14, 15
Brooke, H. J., cited 9
Burke county, N. C, monazite in 21, 26, 27, 32, 36
Canada, monazite in 26
Chemical composition of monazite 7, 14-21
Chemical molecular constitution of monazite 24, 25
Chemical reactions of monazite 22, 23
Children, cited 14
Cleveland county, N. C, monazite in 21, 26, 28, 29, 32, 33, 34, 36
Concentration of monazite 32-35
Country rocks, monazite region 25-27, 28, 29
Cryptolite 7, 9, 11, 15, 29
" crystal form of 11
" identity with monazite 9
Crystal form of cryptolite 11
Crystal form of monazite 10, 11, 12
Cyanite, monazite in 29
Dahll, T., cited ". 10
Damour, A., cited 19
Dana, E. D., cited 12
Dana, J. D., cited 8, 9, 10, 12
Derby, O. A., cited 12, 28, 29
Des Cloizeaux, A., cited 8, 10, 13, 14
Dunnington, F. P., cited 20, 24
Economic use of monazite 30-31
INDEX. 45
Page.
Edwardsite 7, 9, 14
" identity with monazite 9
England, monazite in 26
Eremite 7, 9
" identity with monazite 9
Fiedler, K. G., cited 8
Finnish Lapmark, monazite in 26
Forbes, D., cited 10
France, monazite in 27
Franck, A., cited 12
Genth, F. A., cited 16, 20
Geological and geographical occurrence of monazite 25-30, 32
Georgia, monazite in 26, 28
Germany, monazite in 27
Gorceix, M. H., cited 19
Hermann, R., cited 9, 15, 18, 25
Hidden, W. E., cited 32, 35
Historical sketch of monazite 7-10
Incandescent gas lights 31
Ivester mine, N". C .- 29
Kararfveite 10, 16
" identity with monazite 16
Kersten, C, cited 15, 18, 25
Kokscharow, N. V., cited 9, 10, 12, 15
Konig, G. A., cited 20
Lattimore mine, N. C 33
Levy, A., cited 7
Liversidge, A., cited 19
Localities of monazite 25-27
Mallard, M. E., cited 9
McDowell county, 3ST. C, monazite in 21, 26, 27, 32, 36
Menge, cited 8
Mengite 7, 9
Methods of extraction and concentration of monazite 31-35
Micro-chemical reactions of monazite 23
Miers, H. A., cited 11
Monazite,
Analyses of 17-20
Artificial production of... 25
Associated minerals of 25-27, 30
Blowpipe reactions of 22, 23
Brief description of 7
Chemical composition of 7, 14-25
Chemical molecular constitution of 24, 25
Chemical reactions of 22, 23
Country rocks of 25-27, 28, 29
46 INDEX.
Monazite— Continued. Page.
Crystallization of 10, 11, 12
Derivation of name 9
Earliest recognition of 8
Economic use of 30, 31
Extraction and concentration of 31-35
Geological and geographical occurrence of 25-30. 32
Historical sketch of 7-10
Localities of 25-27
Microscopic distinctions of 13
Method of analysis of 21, 22
Method of formation in beds 30
Micro-chemical reactions of 23
Nomenclature of 7-10
Optical properties of 13, 14
Output and value of in United States 35-37
Percentage of in sand 32, 33, 34
Percentage of in rocks 29
Physical properties of 7, 12, 13
Price of in North Carolina 36
Spectroscopic tests of 23. 24
Use of 30, 31
Variation of thoria in 35, 36
Monazitoid 7, 9, 15
" color of 13, 15
Nomenclature of monazite 7-10
North Carolina monazite region , 26, 27, 30, 32
Norway, monazite in 26, 37
Occurrence of monazite, geological and geographical 25 30, 32
Optical measurements of monazite 13, 14
Output and value of monazite in United States 35 37
Peeler mine, N. C 29
Penfield, S. L., cited 20, 21. 24
Pheifer mine, N. C 34
Phillips, Wm, cited - 8
Phosphocerite 7, 10, 16
" identity with monazite 10
Physical properties of monazite 7, 12, 13
Pisani, F., cited 8, 19
Price of North Carolina monazite 36
Radominski, F., cited 10, 16, 18
Rammelsberg, C. F., cited 18, 19, 24, 25
Rose, G., cited 9
Russia, monazite in 27, 30. 37
Rutherford county, N. C, monazite in 21, 26, 28, 32, 36
Scharizer, R., cited 12, 13, 14, 16
Shepard, C. U., cited 9. 14, 19
1
INDEX. 47
Page.
South America, monazite in 26
South Carolina, monazite in 28, 30, 32
Spectroscopic tests of monazite 23
Sweden, monazite in 26
Switzerland, monazite in 27
Thoria in North Carolina monazite 21, 26
" determination of in monazite 21, 22
" variation of in monazite 35
Trechmann, CO., cited
Turner, E. H., cited
Turnerite
" identity with monazite
United States, monazite in
United States of Colombia, S. A., monazite in
Urdite
" identity with monazite...-
Use of monazite
Vom Rath, GK, cited
Vrba, cited
Watts, H., cited .►. 10,
Websky, cited 10, 16
Welsbach incandescent light 31
Wohler, F., cited 9, 15, 18
Wiilfmg, cited 13, 14
Zschau, E., cited 10
, J.U,
7
7,8,
28
8
25,
26
37
7,
10
10
30,
31
,10,
12
14
,16,
19
NORTH CAROLINA GEOLOGICAL SURVEY
J. A. HOLMES, STATE GEOLOGIST
BULLETIN No. 10
GOLD MINING IN NORTH CAROLINA
AND
ADJACENT SOUTH APPALACHIAN REGIONS
BY
HENRY B. C. NITZE
AND
H. A. J. WILKENS
RALEIGH
Guy V. Barnes, Public Printer
1897.
i
CONTENTS.
PAGE
Illustrations 6
Letter of Transmittal 8
Preface 9
Chapter I. — Geographical and Geological Description of the Gold Belts 11
Virginia Belt 13
The country-rocks 14
The quartz-veins 14
The Eastern Carolina belt 14
The Carolina belt 15
The country-rocks 15
The gold ores 17
Genesis of the ore-bodies 17
The age of the ore deposits 18
The South Mountain belt 18
The country-rocks 18
The quartz-veins 19
The placer deposits 20
Minor belts in North Carolina 20
The Georgia belt . 21
The country-rocks 21
The ore deposits 22
The Carolina belt in Georgia 24
Minor belts in Georgia 24
The Alabama belt 25
Chapter II. — Historical notes ; mining, metallurgical and statistical 26
Early discoveries of gold in the South Appalachian region 26
Early mining operations .* 27
Early mining and metallurgical methods 29
Hydraulic methods 30
Vein mining. Free-milling ores 32
Early milling appliances 33
Treatment of sulphuret ores 36
Mechanical method 36
Chemical treatment 3 7
The chlorination process 37
The cyanide process 38
Other chemical processes 39
Production of gold and silver in North Carolina and other Southern states . . 40
4
4 CONTENTS.
PAGE
Chapter III. — Distribution of gold mines in North Carolina, and mining notes . . 43
The Eastern Carolina belt 43
The Carolina belt 45
Guilford county 45
Randolph county 46
Davidson county 47
Montgomery county 51
Stanly county 54
Moore county 56
Anson county 57
Rowan county 57
Cabarrus county 60
Union county 62
Mecklenburg county 63
Gaston county 66
Lincoln, Catawba, Davie, Alexander and Yadkin counties 68
The South Mountain belt 68
Caldwell county 68
Burke, McDowell and Rutherford counties 68
The mountain counties 70
Chapter IV. — Distribution of gold mines in the South Appalachian region other
than in North Carolina, with mining notes 71
In Maryland 71
In Virginia 71
Fauquier county 72
Stafford county 72
Culpeper county 72
Spottsylvania county 72
Orange county 73
Louisa county 73
Fluvanna and Goochland counties 75
Buckingham county 76
Eloyd and Montgomery counties 76
In South Carolina 76
Carolina belt 77
South Mountain belt 77
In Georgia 78
Rabun county 78
Habersham county 78
White county 78
Hall county 80
Lumpkin county 80
Dawson county 81
Forsythe county 81
Gwinnett county 81
Cherokee county 81
Barton, Cobb, Paulding and Douglas counties 82
Carroll county 82
Haralson county 82
Meriweather county 83
Towne county 84
The Carolina belt (in Georgia) 84
CONTENTS. 5
PAGE
In Alabama, 85
Cleburne county 85
Randolph county 87
Clay county 89
Talladega county 90
In Tennessee 90
Chapter V. — The mining and milling practice at some of the characteristic placer
and free-milling mines 91
The Crawford (or Ingram) mine, Stanly county, N. C 91
The Mills property, Burke county, N. C 95
Placer deposits on Silver creek 97
Placer deposits on Parker branch 101
The Chestatee Company, Lumpkin county, Ga 101
The Chestatee river dredge-boats, Lumpkin county, Ga 106
The Dahlonega method, with special description of the Hedwig mine 107
Historical notes 108
The water-supply 1 08
Mining methods 109
Milling methods 110
Dahlonega method at Hedwig mine 114
The Lockhart mine, Lumpkin county, Ga 115
Chapter VI. — Mining, milling and metallurgical treatment of sulphuret ores at
characteristic mines 117
The Reimer mine, Rowan county, N. C 1 17
The Franklin mine (Creighton Mining & Milling Co.), Cherokee county, Ga. . 121
The Haile mine, Lancaster county, S. C 125
Description of the mine workings, Haile mine 129
Method of working, Haile mine 132
Milling operations, Haile mine 135
Labor, costs, etc., at the Haile mine 142
The Brewer mine, Chesterfield county, S. C 144
Chapter VII. — Some conclusions concerning gold mining in North Carolina and
adjacent South Appalachian regions 118
ILLUSTRATIONS.
PAGE
Plate I. Fig. 1, Log rockers, Gold Hill ; Fig. 2, Chilian mill 30
II. Big Cut, Russell mine, Glen Brook, N. C 53
III. Forty-stamp mill and cyanide plant, Russell mine 53
IV. Hydraulic mining, Parker mine 54
V. Fig. 1, Stand-pipe ; and Fig. 2, sluice-boxes* Parker mine 55
VI. Gold Hill mine, Eames stamp-mill and Barnhardt shaft 60
VII. Catawba mine, 30-stamp mill 67
VIII. Wrought iron siphon pipe, Dahlonega 108
IX. Dahlonega method of mining, giant and ground sluice 109
X. Forty-stamp mill and chlorination plant, Brewer mine 147
Fig. 1. Gold belts of the Southern states 12
2. Cross-section, Thompson mine 22
3. Map of North Carolina showing gold distribution 44
4. Map showing distribution of veins at Gold Hill 59
5. Plan of Capps mine 65
6. Method of working gravel at Crawford mine 92
7. Rocker used by tributors, Crawford mine 94
8. Riffles in sluice-box, Crawford mine 94
9. Proposed hydraulic work on Mills property 96
10. Flume, Mills property 98
11. Hydraulic gravel elevator, Mills property 99
12. Section of sluice-box, Mills property 100
13. Plan of hydraulic lift 103
14. Plan of setting hydraulic lift 105
15. Plan of portable tailings flume 105
16. Vertical cross-section of the Hall stamp-mill 110
17. Vertical longitudinal section of the Hall stamp-mill 112
18. Vertical section, Reimer mine 118
19. Mecklenburg Iron Works, 750-pound battery 120
20. Vertical section, Franklin mine 122
21. Haile mine, outline map of region 12 7
22. Plan and section of Beguelin part of Haile mine 128
23. Plan of Cross mine, Haile Gold Min. Co 130
24. Method of stoping at Cross mine 133
25. Vertical skip used at Haile mine 134
26. Section of 60-stamp mill, Haile mine 136
27. Double-hearth roasting furnace, Haile mine 13S
28. Chlorination plant at Haile mine, longitudinal section 139
"29. Chlorination plant at Haile mine, cross section 140
30. Chlorination-barrel, Haile mine 141
31. Plan of Brewer mine, Chesterfield county, S. C 146
jfartK Carolina
J I
BOARD OF MANAGERS.
Governor D. L. Russell, ex-officio Chairman,
Charles McEamee, .
J. Turner Morehead, ....
Raleigh.
Biltmore.
Leaksville.
STATE GEOLOGIST.
J. A. Holmes,
Chapel Hill.
LETTER OF TRANSMITTAL.
To His Excellency, Hon. D. L. Russell,
Governor of North Carolina.
Sir: — I have the honor to transmit for publication as bulletin 10 of
the Geological Survey series, a report on the subject of Gold Mining
and Mining Methods in North Carolina and adjacent South Appalachian
regions. The Survey has received many requests for information con-
cerning this subject, and it is in response to these that I recommend the
publication of this report. Many applications for copies of it have been
received in advance of its appearance.
Yours obediently,
J. A. Holmes,
State Geologist,
Raleigh, N. C,
July 1, 1897.
i
PREFACE.
During the past few years the Survey has received from persons
interested in gold mining in North Carolina, numerous inquiries con-
cerning the mining and metallurgical methods which have proven most-
successful in operating gold mines in this and other South Appalachian
regions. In response to these inquiries, an investigation was undertaken
of this subject in 1895, by Mr. H. B. 0. Nitze, of the Survey, and Mr.
H. A. J. "Wilkens, a mining expert of Baltimore, who visited during that
year the more important mining regions in North Carolina and other
Southern States. A preliminary report of their examinations was read
at the Atlanta meeting of the American Institute of Mining Engi-
neers (October, 1895), and was published in the Transactions of the
Institute for that year.
In the present publication that paper has been partly reproduced, but
it has been largely rewritten, elaborated and brought down to the end
of 1896. No attempt has been made to describe all of the mines or even
to present detailed descriptions of all of the more important mining
regions to be found in North Carolina and adjacent States. Only such
mining and metallurgical methods practiced in this and the other States
are here described as it is believed will be found useful in a study of
the best methods for use in the development of the North Carolina gold
fields. This report may be regarded as being in a measure supplemental
to Bulletin 3 (Gold Deposits of North Carolina), published by the
Survey in 1896, which described with more detail the gold-mining
regions in this State.
The descriptions given in the report are based almost wholly upon the
personal examinations of Messrs. Nitze and Wilkens. They have, how-
ever, made use of data relating to the different mining regions to be
found in Mr. Geo. F. Becker's valuable " Reconnoissance of the Gold
Fields of the Southern Appalachians," and the reports by the several
State Geological Surveys, the sources of information being indicated in
each case by footnotes. Persons desiring to consult other publications
10 . PREFACE.
relating to this field will find a full bibliography in the above-mentioned
report of Mr. Becker's, published by the U. S. Geological Survey.
Messrs. Mtze and Wilkens have been aided in the preparation of their
statement concerning the Haile mine in South Carolina by Mr. A. Thies.
Capt. John Wilkes, of the Mecklenburg Iron Works, Charlotte, X. C,
has also aided them by the loan of drawings, maps and in other ways.
Mr. Geo. B. Hanna, of the U. S. Assay Office, at Charlotte, X. C, has
kindly furnished numerous notes concerning the history of mining and
metallurgical methods in the entire South Appalachian region. In
behalf of the Survey and of the authors, I desire to thank these gen-
tlemen and many others, in different parts of the region, who have in
various ways rendered assistance in the collection and preparation of
information for this report. I desire further to thank the editors of
The Transactions of the American Institute of Mining Engineers and
The Engineering Magazine for permission to use electrotypes of plates
prepared for those publications.
One of the existing needs of the North Carolina gold field is the
establishment at central points in this region of practical plants that will
successfully treat the low-grade sulphur et ores — plants that will do
custom work at reasonable prices, and where individual miners can
ship their ore and be paid for the same according to its value, as is the
case in the great mining regions of the West.
J. A. Holmes.
i
GOLD MINING IN NORTH CAROLINA AND ADJACENT
SOUTH APPALACHIAN REGIONS.
By H. B. C. Nitze and H. A. J. Wilkens.
CHAPTER I.
GEOGEAPHICAL AND GEOLOGICAL DESCRIPTION OF
THE GOLD BELTS.
The gold fields of the Southern Appalachians are situated in the area
of the crystalline rocks extending from the vicinity of "Washington in a
general southwesterly direction, through the piedmont and mountain
regions of Maryland, Virginia, North Carolina, Tennessee, South Caro-
lina, Georgia, and Alabama, to the vicinity of Montgomery.
The greatest width of the belt, as a whole, is attained in North Caro-
lina, South Carolina and Georgia, where it is from 100 to 150 miles,
narrowing down in Virginia and Maryland on the northeast and in
Alabama on the southwest (see map, fig. 1).
In chapters III and IV the gold-mining counties of these States are
given.
The general term crystalline rocks includes gneisses, argillaceous,
hydro-micaceous, chloritic, siliceous and other schists and slates, lime-
stone, granite, diorite, diabase and other eruptives, as well as certain
volcanic porphyries, etc., and pyroclastic breccias. The age of these
rocks is Archaean, Algonkian, and possibly in part Paleozoic. On the
east they are covered by the Coastal Plain and in places by small patches
of the Jura-trias (Newark), which latter also occur within the area in
small isolated basins, notably in Virginia. On the west they are bor-
dered by the Paleozoic rocks.
The rocks of the gold belt are decomposed to depths often reaching
50 and 100 feet. Mr. Becker has proposed and used the term "sapro-
lite," x signifying literally " rotten rock," as a general name for such
thoroughly decomposed, earthy, but untransported rock.
Eor geological reasons and for descriptive convenience this gold belt
1 "'Reconnoissance of the Gold Fields of the Southern Appalachians, by G. F. Becker, Six-
' teenth Annual Report of the 77. S. Geological Survey, 1894-5, part iii, pp. 289-90.
12
GOLD MINING IN NORTH CAROLINA.
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS.
13
of the Southern Appalachians is differentiated into the following com-
ponent belts:
1. The Virginia Belt. 4. The South Mountain Belt.
2. The Eastern Carolina Belt. 5. The Georgia Belt.
3. The Carolina Belt. 6. The Alabama Belt.
Other divisions might be made as, for instance, the isolated belts of
auriferous rocks west of the Blue Ridge in Virginia, North Carolina,
Georgia and Tennessee, and various minor belts in Georgia and Ala-
bama; but such subdivision is unnecessary for the purposes of this paper.
In Bulletin 3, " The Gold Deposits of North Carolina," the Carolina
Belt has been differentiated into the Carolina Slate, the Carolina Igneous
and the Kings Mountain belts. For the purpose of this paper, how-
ever, where the geological descriptions of these various belts can only be
briefly taken up, the above six main divisions will suffice, and for fuller
and more detailed descriptions the reader is referred to the following
papers :
u . Reports on the Surveys of South Carolina," by O. M. Lieber, Co-
lumbia, S. C, 1856, 1857, 1858, and 1859.
"A Reconnoissance of the Gold Fields of the Southern Appalach-
ians," by George F. Becker.1
" The Gold Deposits of North Carolina," by H. B. C. Mtze and G. B.
Ilanna.2
" The Lower Gold Belt of Alabama," by William B. Phillips.3
" Mineral Resources of the Upper Gold Belt (of Ala.)," by Win. M.
Brewer and others.4
Work has been in progress by the Geological Surveys of Georgia and
Alabama on the gold fields, and reports from these respective bureaus
are expected to be published shortly.
1. THE VIRGINIA BELT.
This belt begins in Montgomery county, Maryland, and extends in a
southwesterly direction, parallel to and on the east side of the Blue
Ridge, to the North Carolina line. The best and most reliable, though
incomplete, information regarding the geology of this region is given in
the early reports of Prof. William B. Rogers (1835, 1836 and 1S40V
The width of the belt is from 9 to 20 miles, covering an area of some
4000 square miles, and its best developed portion is in Fauquier, Cul-
1 U. S. Geological Survey, Sixteenth Annual Report, 1894-95, part iii, pp. 251-331.
2 North Carolina Geological Survey, Bull. No. 3, 1896.
3 Geological Survey of Alabama, Bull. No. 3, 1892.
4 Geological Survey of Alabama, Bull. No. 5, 1896.
5 The Geology of the Virginias, D. Appleton & Co., New York, 1884, pp. 74-80, 131-132, 458-460.
14 GOLD MINING IN NOKTH CAROLINA.
peper, Stafford, Orange, Spottsyrvania, Louisa, Fluvanna, Goochland
and Buckingham counties.
THE COUNTRY-ROCKS.
The rocks of the Virginia belt are mica-gneisses and schists, often
garnetiferous, hydro-micaceous and chloritic. The strike is X. 20°-30°
E., and the dip easterly at varying angles. Mr. S. F. Emmons1 gives
the prevailing strike in Montgomery county, Maryland, as north and
south, and the dip nearly vertical or very slightly inclined to the east-
ward. Granite and diabase dikes occur in the region, and these are
sometimes sheared. In some private notes on the Arminius pyrite mine,
in Louisa county, Va., Mr. Becker says:
" The principal country rock is a series of micaceous schists Indica-
tions are not wanting that a portion of these schists is of sedimentary origin.
.... On the other hand, it is equally certain that the most prominent charac-
teristics of the schists are of dynamic origin. . . . Much of the schist looks as if
it were derived dynamically from granite."
THE QUARTZ-VEINS.
The auriferous quartz-veins conform in the main to the strike and dip
of the enclosing rock. However, their origin is not coeval, the schistose
structure antedating the formation of the veins. Neither must their
approximate conformity to the country be taken in the absolute sense,
for they often cut the schists at small angles both in dip and strike.
The structure of the veins is irregularly lenticular, varying from a few
inches to several feet in thickness. The wall-rock is often impregnated
with auriferous pyrites to considerable extent. Some of these veins are
of remarkable persistency and continuity, as, for instance, the Fisher lode
in Louisa county, which has been opened for a distance of some five
miles along the strike to a maximum depth of 220 feet by the Warren
Hill, Louisa, Slate Hill, Luce and Harris mines.
The gravel placer deposits of the Virginia belt are in all respects simi-
lar to those of other gold regions.
A small isolated gold belt is situated on the west side of the Blue
Bidge in Montgomery, Floyd and Grayson counties, but it is of little
economical importance and will not warrant more than this passing
mention. The auriferous copper ores of Ashe and Watauga counties,
N". C., also appear to belong here.
2. THE EASTERN CAROLINA BELT.
This forms a small and narrow area in Halifax, Warren, ^ash and
Franklin counties. It is covered on the east by the Coastal Plain and
1"Noteson the Gold-Deposits of Montgomery county, Md.," by S.F.Emmons. Trans. Am.
Inst. Min. Eng., xviii, 391-411.
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. 15
bounded on the west by the Louisburg granite. The country rock is
diorite, in great part sheared to a chloritic schist (as at the Mann-
Arrington mine). The strike of the schists is !N". 50°-60° E., and the
dip 25°-40° S.E. Other intrusives, such as diabase, occur in the region.
The quartz-veins. — These occur (1) as lenses, from minute size
up to 12 inches in thickness, interlaminated in the schists or cutting
them at small angles; (2) as a reticulated network in the massive rocks.
It is stated that the saprolites are auriferous over large areas and will
repay hydraulic mining.
3. THE CAROLINA BELT.
This belt is one of the most extensive and important in the Southern
Appalachians, though lying far to the east of the Blue Ridge. It is
situated in the central Piedmont region, and extends from the Virginia
line in a southwesterly direction across the central part of North Carolina
into the northern part of South Carolina, where it sinks beneath the
Coastal Plain, making its re-appearance in Abbeville county, S. C, and
in Wilkes, McDuffie and adjacent counties in Georgia, near Augusta.
There are no mountain chains in the Carolina belt, the only prominences
of consequence being a low range of hills known as the Uharie moun-
tains, in Montgomery county, N". C, and the isolated peaks of Crowders
and Kings mountains in Gaston county, :N". C, extending into York
county, S. C.
The belt varies in width from 8 to 50 miles; it is bounded on the east
by the Jura-trias (Newark) and the coastal plain formations.
THE COUNTRY-ROCKS,
The gold-bearing rocks of the Carolina belt are (1) argillaceous, seri-
citic and chloritic metamorphosed slates and schists; (2) devitrified an-
cient volcanics (rhyolite, quartz-porphyry, etc., and pyroclastic brec-
cias); (3) igneous plutonic rocks (granite, diorite, diabase, etc.); (4) sili-
ceous magnesian limestone; (5) sedimentary pre-Jura-trias slates. The
Jura-trias conglomerates along the eastern boundary have also been
found to contain gold, but not in quantities of economical importance.
The argillaceous and sericitic 1 slates and schists, though in general
highly metamorphosed and sheared, show many evidences of sedimen-
tary origin. The siliceous magnesian limestones (Kings mountain,
etc.), must be included here. All of these rocks are non-fossiliferous
and must be provisionally classed as Algonkian. They are often silici-
fied in varying degrees up to a completeness which renders the rock so
^he general term "talc" schists, so often used, is very loosely applied, and generally in-
correctly, as the true "talc "schists are comparatively rare; it should, from a niineralogical
standpoint, more properly be hydro-mica or sericite schists.
16 GOLD MIXING- IN NORTH CAROLINA.
hard that it resists scratching with a knife. The chloritic schists are
more truly the crystalline schists, and probably represent the sheared
basic eraptives. They are even porphyritic and brecciated in places.
They are not so abundant as the argillaceous schists, and are richer in
accessory rnetamorphic minerals, such as garnet and epidote.
The general strike of the schist osity is ~N. 20°-55° E., and the pre-
dominating dip to the !N". W. from 55°-85°. In many cases the force
producing schistosity and slaty cleavage appears to have acted downward
from the 2s".W.? developing normal faulting with but little deformation.
The volcanic rocks occupy irregular patches along the eastern border
of the belt, in close proximity to the western edges of the Jura-trias
basins. They comprise both acid and basic types. The acid rocks are
generally devitrined to such an extent that their real character is no
longer recognizable to the naked eye, and they appear as ordinary cherts
or hornstones, although flow-structure is at times still discernible. Micro-
scopic examination shows them to belong to the class of rhyolites and
quartz-porphyries. They are sometimes sheared into schists, as for in-
stance at the Haile mine, S. C. The basic types are dark green in color
and perhaps pyroxenic in composition; they are sometimes massive por-
phyrites, but more generally sheared into schists. The pyroclastic brec-
cias consist of angular fragments of the acid rhyolites and porphyries in
a basic matrix. The age of these ancient volcanics is believed to be pre-
Cambrian. They seem to be analogous to, and probably contempora-
neous with, similar rocks of the South mountain in Maryland and Penn-
sylvania, and other points along the Atlantic coast. The igneous plu-
tonic rocks lie on the western side of the central slates; they consist of
granites, diorites, gabbros, diabases, etc. In point of age they are sup-
posed to be younger than the slates and schists on the east. Diabase
dikes are common in the Carolina belt, and appear in general to have
exercised a favorable influence on the richness of the ore-bodies which
they intersect; the ores often are richer in the vicinity of the dikes. At
the Haile mine, in Lancaster county, S. C, this is very marked.
The sedimentary pre-Jura-trias slates, mentioned above as the fifth
class of gold-bearing rocks, are perhaps best developed near Monroe,
ITnion county, !N". C, and have therefore been called the Monroe slates.
These slates are but little indurated and lie in flat-bedded alternating
synclinals and anticlinals. They cover a considerable area, extending
from Monroe northward and eastward, and appearing in Stanly and
Montgomery counties. They dip under the Jura-trias conglomerate
near Polkton, 20 miles east of Monroe, and might be looked upon as
Lower Paleozoic ; but the absence of fossils, so far as present search has
gone, must, for the time being, place them provisionally in the Algon-
kiar.
a
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. 1<
THE GOLD ORES.
The gold ores in the Carolina belt exist in two principal structural
forms: (1) as quartz fissure-veins; (2) as pyritic impregnations, ac-
companied by irregular stringer-like and lenticular quartz intercalations
in the country schists and slates. The fissure-veins in the slates and
schists are generally difficult to distinguish as such. Their structure is
much more evident in the granitic and other eruptives. In the schists
the larger and more regular quartz lodes lie apparently interlaminated
with the country, or have the appearance of lenticular intercalations;
however, even here they can usually be shown to intersect the schis-
tosity, generally at very low angles.
The age of the ore deposits is later than that of the force which pro-
duced schistosity, from the fact that fragmental inclusions of sheared
country-rock are not rare in quartz. The fissuring force was, there-
fore, subsequent to the shearing force. Certain maximum lines of fault-
ing may have been developed, which made room for the larger fissure-
veins, on either side of which smaller dislocations formed belts of varia-
ble width. It is certainly most natural that, in a rock like slate or schist,
the rupturing force should have been exerted along the lines of least
resistance, that is, along the cleavage planes, and that the predominating
fissures should, therefore, have been formed in that direction. Isolated
instances of cross-fissures occur, but they are rare.
A very usual occurrence of the ores is that of irregular, finely-divided
disseminations of auriferous sulphurets and fine gold, accompanied by
small stringers and lenses of quartz in the country slates and schists,
which are usually silicified, at least to some extent. This form of deposit
bears close resemblance to the Scandinavian " fahlbands," which are de-
scribed as belts of schists impregnated with sulphides. In the Southern
Appalachian field they form the small and large bodies of low-grade ores
(Haile mine, Russell mine, etc.). The shape of these ore-bodies is lenti-
cular; their outline, however, does not necessarily conform with the
strike and dip of the schists, but is determined rather by the degree of
impregnation. Very often, also, the wall-rock of the quartz fissure-veins
is impregnated for some distance with auriferous sulphurets.
The gravel placers of the Carolina belt present no features differing
from those of similar deposits in other gold regions.
GENESIS OF THE ORE-BODIES.
"No definite proof of metasomatic formation of the ores has been ob-
served; and the most reasonable hypothesis for their formation is that
of the ascension and percolation of heated carbonated and alkaline waters
carrying silica, metallic elements and sulphides in solution, and the depo-
IS GOLD MINING IN NORTH CAROLINA.
sition of their mineral contents in the open spaces through which they
circulated, by relief of pressure, reduction of temperature, and perhaps-
certain chemical reactions. The frequent siliciflcation of the slates and
schists has been noted, and must be ascribed to this permeation of the
silicifled waters.
The character of the quartz varies from saccharoidal to vitreous, usu-
ally inclining to the latter. The sulphurets are chiefly pyrites; chalco-
pyrite, galena, mispickel and zinc-blende occur in certain localities, not-
ably at the Silver Hill and Silver Valley mines, in Randolph county.
!N". C. Copper ores (chalcopyrite) in some of the Xorth Carolina mines
are auriferous to such an extent as to make them valuable for gold also.
as for instance at the Conrad Hill. Tellurides have been found in very
small quantities, as at the Kings Mountain mine, X. C. Among the
more common gangue minerals, besides quartz and sulphurets, are
chlorite, barite and carbonates.1
THE AGE OF THE ORE DEPOSITS.
The formation of the ores took place subsequent to the production of
schistosity. The fact that the Jura-trias conglomerates, on the east,
contain gold proves that the origin of the gold must have been pre-Jura
Triassic. The presence of gold-bearing fissure-veins in the Monroe slate?
shows that their age must be Algonkian or later. The existence of ore-
bodies in the pre-Cambrian volcanic rocks furnishes another clue; and
thus it becomes probable that the age of the gold ores in the Carolina
belt is Algonkian.
4. THE SOUTH MOUNTAIN BELT.
This belt is situated in the western part of North Carolina, and takes
its name from the South mountains, one of the eastern outliers of the
Blue Ridge. The principal mining region embraces an area of 250 to
300 square miles, in Burke, McDowell and Rutherford counties, extend-
ing from Morganton to near Rut-kerf ordton, a distance of about 25
miles, with an average width of 10 to 12 miles. The gold veins of
northern Burke and Caldwell counties on the north, and Cleveland and
Polk counties, X. C, on the south, as well as Spartanburg. Greenville
and Pickens counties, S. C, might be considered as belonging to this
general belt; but no extensive operations have been carried on there.
THE COUNTRY-ROCKS.
In the South mountain region, the crystalline rocks are for the most
part Archaean micaceous (biotite) and hornblendic gneisses and schists.
1 Mr. Becker, in the paper referred to above, pp. 274-278, tabulates no less than 60 gangue
minerals, besides quartz, pyrite, and the ordinary products of decomposition.
I
1
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. 19
having an eminently lenticular structure. They are often garnetiferous
and contain also many of the rarer accessory minerals, such as zircon,
monazite, xenotime, etc. These gneisses are considered to have been
igneous granites and diorites, subsequently rendered schistose by
dynamo-metamorphism. The general strike of the sehistosity is N. 10°-
25° "W., and the dip 20°-25° N.E. To the northwest of South Muddy
creek and Vein mountain, however, the strike is generally N. E. and
the dip S. E. This is the case also in the northern part of the general
belt, in Caldwell county.
Isolated masses of pyroxenite and amphibolite occur as rounded inclu-
sions or blebs, from less than 1 to nearly 100 feet in diameter, in the
gneiss. They are looked upon as basic segregations from the original
igneous magma out of which the gneisses were formed. They alter to
talc and serpentine.
Pegmatites are of frequent occurrence in the gneisses, and like them
their structure is usually lenticular. At several points there are indi-
cations of pegmatite dikes. Granite dikes occur in the South mountain
region; and in the northern part of the belt, in Caldwell county, a very
persistent and continuous dike of aphanitic olivine diabase has been
observed. Brown mountain, in the northern part of Burke county, is
made of granite.
THE QUARTZ-VEINS.
The auriferous quartz-veins of the South mountain belt form a system
of parallel fissures of remarkable regularity, striking t>T. G0°-70° E. and
dipping 70°-80° N.W. Their thickness varies from that of a knife-
edge to 4 feet. The great majority are from less than 1 to 3 inches in
thickness, lying in zones of scores of small veins; the larger ones (1 to 4
feet) are few and far between. Normal faulting has been observed in a
few instances. The ore is quartz, usually of a milky white color, gener-
ally saccharoidal and seldom vitreous or glassy. It is often stained
brown and is cellular from decomposed sulphurets. The sulphurets are
pyrite, galena, chalcopyrite, and zinc-blende. All observations go to
show that the vein-matter is formed from ascending mineralized solu-
tions. There is no evidence of the replacement of the country rock by
ore.
In the South mountain region proper there are five parallel lines or
zones along which these quartz-veins appear to be concentrated:
1. The Morganton zone, passing through Morganton, along Little
Silver creek and through the Neighbor's place to North Muddy creek.
2. The Huntsville zone, passing over the southern end of Huntsville
mountain.
3. The Pilot mountain zone, passing over Halls knob, Whites knob,
>
20 GOLD MINING IN NORTH CAROLINA.
Pilot mountain, Brackettown, and Vein mountain, to and beyond the
Second Broad river.
4. The Golden valley zone, passing across the upper end of the Gol-
den valley (valley of the First Broad river) and crossing Cane and Camp
creeks to the Second Broad river.
5. The Idler mine zone, about 3 miles north of Butkerf ordton.
The great majority of these auriferous quartz-veins are too small to
be profitably worked individually. Of the larger and more promising
veins which have been worked, the " Nichols," at Vein mountain (18
inches to 3 feet), and the "Idler," near Butherfordton (22 inches), may
be mentioned.
THE PLACER DEPOSITS.
The principal mining ground of the South mountain region is that
of the placer deposits. These are of three classes: 1. The gravel de-
posits of the stream-beds and bottom-lands, deposited by nuviatile action.
2. The gulch and hillside deposits, or accumulations due to secular dis-
integration and motion induced by frost action and gravity. 3. The
upper decomposed layer of the country-rock in place, the saprolites.
In the first class the gravel is water-worn, rounded to subangular,
and the dejDOsits are from 1 to 2 feet in thickness. In the second class
the gravel is usually quite angular, and the deposits are from a few
inches to several feet in thickness. In the third class gravel is of
course absent, the washable ground consisting of the upper decomposed
layer in place, the gold being derived directly from the partially dis-
integrated quartz-veins.
5. MINOR BELTS IN NORTH CAROLINA.
On the west side of the Blue Bidge, in Henderson county, N. C,
gold has been mined at the Boylston mine. The country rocks are
fine-grained mica- and hornblende-schists, in part much crumpled. The
general strike is K 20°-30° E., and the dip is K¥. The schists are
cut by a granite dike. The valley of Boylston creek is made up of
schistose limestone, underlying these crumpled schists. These rocks
are probably to be classed in the Ocoee, which by some is supposed to
be Algonkian and by others Baleozoic, and by others still, it is believed
to contain formations of different ages ranging between these two.
This isolated belt, however, has little economic importance in connec-
tion with gold deposits.
Another belt of auriferous rocks is that in which some unimportant
placer-mining operations have been prosecuted in Swain, Jackson,
Macon, Clay, and Cherokee counties, !N\ C. The country-rock is sup-
posed to be largely Ocoee. In Tennessee the petty stream deposits of
i
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. 21
Polk, McMinn, Monroe and Blount counties are probably in the same
horizon.
6. THE GEORGIA BELT.
The Georgia belt is probably of next or equal economic importance
to the Carolina belt. Beginning in Rabun and Habersham counties,
in the northeastern corner of the State, it extends in a southwesterly
direction through the important mining town of Dahlonega, and thence
to the Alabama line in the vicinity of Tallapoosa. This is in the Pied-
mont region of the State, lying on the southeast side of the Blue Ridge.
Although the maximum width (N.W. and S.E.) over which the mines
are distributed is as great as 30 miles, the principal portion of the belt,
which extends from near Canton, in Cherokee county, through Dah-
lonega and JNTacoochee, to Clayton, in Rabun county, is concentrated
in a width of 4 miles or less. It is to this latter portion that the fol-
lowing geological descriptions more especially relate.
THE COUNTRY-ROCKS.
The rocks of this belt resemble in many respects those already de-
scribed under the South mountain belt in North Carolina. They are
Archaean micaceous and hornblendic gneisses and schists, which probably
represent sheared granitic and dioritic rocks. At the Murray mill, on
Yahoola creek, near Dahlonega, a large mass of unsheared granite
may be seen; and massive granite is reported to exist on Yonah Peak,
near Nacoochee. These gneisses and schists are banded in narrow.,
lenticular-shaped layers, from 2 to 20 feet wide. A dark-colored,,
schistose hornblende rock, locally known as " brick-bat," is of frequent
occurrence. Its structural relations are very difficult to determine; at
times it is conformably interlaminated with the other schists (as at the
Hedwig mine, near Auraria); again, it appears to have no regular rela-
tion in its position to the adjoining schists, which are cut off by it or
very markedly disturbed in their strike, bending around the " brick-
bat " mass, and developing a crumpled or folded structure in the schis-
tose laminae (as at the Singleton and Lockhart mines, near Dahlonega).
It is possible that these " brick-bat " masses, which appear to be dioritic
in origin, are magmatic segregations or blebs, similar to the pyroxemV
and hornblendic blebs described in the South Mountain region,1 though,
as a rule, larger. The prevailing strike of the gneisses and schists is
N. 20°-30° E., and the dip 30°-60° S.E. Locally, however, in the
presence of the dioritic masses, as explained above, this changes to
northwest strikes with northeast dips. The rocks are often garnet-
iferous and contain rarer accessory minerals, such as monazite, though
1 See page 18, above, and Bull. 3, North Carolina Geological Survey, 1896, p. 157.
2 At the Glades Post-Office, in Hall county, 10 miles northeast of Gainesville, monazite has
been found in some quantity.
99
GOLD MINING IN GEORGIA.
to a much lesser degree than in the South mountain rocks. The depth
of the saprolites in the Georgia belt reaches a maximum of about 100
feet.
Diabase' dikes, such as are common in the Carolina belt, are not
found in the Georgia belt. Granitic dikes are, however, not uncommon
in the Nacoochee region.
Fig. 2. — Cross-section in Opening at Thompson mine, near Nacooehee, Ga. Scale,
1 inch=2 feet, a, quartz; b, slate; c, granite dike; d, -wall rock.
The accompanying sketch (fig. 2) represents a small pegmatite dike
at the Thompson mine, 4 miles west of Nacooehee, showing the develop-
ment of normal faulting. Similar granitic dikes have been found in
Cherokee county, near the Franklin mine. In the Dahlonega district,
although no unquestionable well-marked dikes are seen in place, Mr.
Becker 1 calls attention to the possibility that some of the unusually
sharply marked sheets in the gneiss might be intrusive.
THE ORE DEPOSITS.
Certain bands of the gneisses and schists have been fissured and filled
with gold-bearing quartz and sulphurets. These fissures are in the
14'Reconnoissance of the Gold Fields of the Southern Appalachians," Sixteenth Annual Ei
port of the U. S. Geological Survey, 1894-5, part iii, p. 296.
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. 23
main parallel to the schistosity of the rock, though not uncommonly
they cut the same at low angles. To a large extent they are aggre-
gated in a zone of numerous narrow and discontinuous lenses and
stringers through more or less definite bands of the gneiss, which, taken
altogether, form the vein. This is well illustrated in Fig. 2. Mr.
Becker has designated such a system, a " stringer-lead." In these
narrow, sharply-banded gneisses and schists of different material, such
as they are in this part cf the Georgia belt, it is natural that the frac-
turing force, once exerted in a certain band, should have been more or
less confined to this one, both longitudinally and transversely, the walls
of the band forming the walls of the ore-body. This is in fact the
case. At times the Assuring is confined to the light-colored mica-
gneisses, at other times to the dark-colored ferromagnesian gneisses and
schists. The " brick-bat " schists rarely contain ore-bodies. The thick-
ness of the veins is from less than 3 to as much as 20 feet; they are
frequently close together, separated by non-auriferous bands of gneiss;
and the total width of the ore-bearing ground reaches as much as 200
feet (Singleton mine, Dahlonega). The extent of fissuring must de-
pend largely on the degree of homogeneity of the material, as well as
on the intensity of the fracturing force. Where the rock is of homo-
geneous composition and the force uniformly exerted, the effect would
be a more or less evenly distributed shattering, with few gaping fis-
sures, and the whole mass would be permeated by the gold-bearing
solutions, with the formation of auriferous and pyritic impregnations,
with some small quartz-stringers. At the Hedwig mine, near Auraria,
for instance, regular quartz masses of any size are altogether absent,
the ore-body being composed of soft, sandy, mica-gneisses and -schists
containing only a few, small and isolated quartz-stringers. Again, under
different conditions, the effect was the production of a large number
of small open fissures, inducing the consequent formation of numerous
small lenticular quartz-stringers; and such is the usual case in the
Dahlonega ore-bodies (fig. 2, p. 22). Or, where the rock mass was of
still greater heterogeneity, and the forces of greater or more varied
intensity, lenticular fissures have been opened, of such size and extent
as to allow a more or less complete filling by solid auriferous and pyritic
■quartz, from 3 to 14 feet in thickness; while, further along the strike,
though the fracturing extends to the same width and the walls hold out,
the intervening space of country has simply been shattered, or opened
only in small spaces, but was nevertheless filled with pyritic impregna-
tions and quartz-stringers, (as at the Franklin mine in Cherokee county,
where these barren portions of the vein are called horses). But the
144 Reconnoissance of the Gold Fields of the Southern Appalachians,'" Sixteenth Annual Re-
port of the TJ. S. Geological Survey, 1894-5, part iii, p. 283.
24 GOLD MINING IN GEORGIA.
leads are continuous, usually for considerable distances. At the Lock-
hart mine, near Dahlonega, for instance, the Blackmore vein, 3 to 6
feet in thickness, has been opened by a drift 400 feet long. At the
Franklin mine, in Cherokee county, the ore-body has been explored by
underground workings for 1000 feet, and the continuity of the vein
has been traced for three-quarters of a mile by isolated shafts. The
regularity of the vein structure at the Franklin is exhibited by well-
defined walls, and by the presence of a soft " gouge " on both the foot
and hanging, even where there is no marked quartz filling.
Small, clean-cut cross-fissures occur in the Georgia belt, as at the
Franklin mine, where the filling is chiefly calcite.
The pitch of the ore-bodies in the Georgia belt is as a rule to the
northeast. The filling of the fissures is quartz, carrying pyrite and
rarely chalcopyrite. Among the most interesting gangue minerals may
be mentioned garnets, which in cases have been found to be auriferous.1
Another occasional, though rare, gangue mineral is tourmaline. Gold
in close association with a tellurium mineral has been found in the
so-called " Boly Fields " vein on the banks of the Chestatee river.2 The
character of the quartz varies greatly, from very saccharoidal to ex-
tremely vitreous types, and from clear transparent to milky-white in
color, sometimes smoky.
The genesis of the ore deposits is best explained by the ascension
theory; there is no evidence of substitution. The formation of the ore
deposits was subsequent to the force that sheared the country-rock, from
the fact that fragments of the schistose country occur in the quartz.
The character of the gravel placer deposits in the Georgia belt is
similar to that in the South Mountain belt.
THE CAROLINA BELT IX GEORGIA.
Mention has already been made (p. 15) of the extension of the Caro-
lina belt into Wilkes, McDufrie and adjacent counties, Georgia.
MINOR BELTS IX GEORGIA.
The crystalline rocks of Georgia are comprised in the large area lyings
north of a straight line drawn from Augusta to Columbus. Within this
area there are, besides the principal gold-ore belts mentioned above, a
large number of minor belts; in fact, almost every county in the region
claims some discovery of the precious metal. Among the more impor-
tant are a belt including portions of Gwinnett, Milton, DeKalb, Fulton.
Campbell, Fayette, Coweta, Meriwether and Troup counties: and a
"Reconnoissance of the Gold Fields of the Southern Appalachians." Sixteenth Annual Re-
port of the 77. S. Geological Survey, 1894-5, part iii, pp. 279, 297.
2 See paper by Dr. Wra. P. Blake, Trans. Am. Inst. Min. Eng„ Vol. xxv, 1896, p. 802.
4
GEOGRAPHICAL AND GEOLOGICAL DESCRIPTION OF GOLD BELTS. ZO
small belt lying on the northwest side of the main Blue Ridge divide,
in Towns, Union and Fannin counties, extending into Clay county, ~N. C.
7. THE ALABAMA BELT.
The Alabama belt might be considered a continuation of the Georgia
belt. However, principally as a matter of convenience for reference,
it is spoken of and described separately here. It comprises an area of
about 3500 square miles, situated in the crystalline rocks of Cleburne,
Randolph, Talladega, Clay, Tallapoosa, Chambers, Coosa, Elmore and
Chilton counties. This is the southwest extremity of the southern
Appalachian gold field.
On the latest geological map of Alabama,1 the gold-bearing rocks of
this area are distinguished as: 1. The semi-crystalline Talladega shales
of Algonkian age, including argillaceous and hard, greenish, sandy
shales (often graphitic); 2. The crystalline schists of Archaean age, in-
cluding mica-schists, which, on the one hand, grade through gneisses
into granite, and, on the other, into siliceous schists; garnetiferous horn-
blende-schists, probably of dioritic origin, also occur. The general
strike is KE. and the dip S.E.
The quartz-veins are interlaminated in these rocks, coinciding imper-
fectly with the dip and strike of the schistosity. Erom a structural
geological standpoint, the veins bear much similarity to those of the
Dahlonega type. From a mining standpoint, however, they are dif-
ferent, not forming the wide belts of numerous parallel leads, as in
Dahlonega. The quartz is usually glassy; the sulphurets are in the
main pyritic, and the gangue minerals are those of usual occurrence in
gold-bearing quartz-veins elsewhere. The character of the placer de-
posits presents no novel features.
1 Geological Map of Alabama, with Explanatory Chart, Geological Survey of Alabama, 1894.
CHAPTER II.
HISTOKICAL NOTES: MINING, METALLURGICAL AND
STATISTICAL.1
EARLY DISCOVERIES OF GOLD IN THE SOUTH APPALACHIAN
REGION.
For an account of probably the earliest discoveries of gold in the
southern part of what is now the United States by the Spanish ex-
plorers we refer the reader to Mr. G. E. Becker's paper, Beconnoissance
•of the Gold Fields of the Southern Appalachians.2
Reports of the existence of gold in the Southern States antedate the
time of the Revolutionary war, as for instance, in South Carolina at
the Brewer mine in Chesterfield county, and in North Carolina at the
Oliver mine in Gaston county, the Dunn mine in Mecklenburg county,
and the Parker mine in Cherokee county.
However, no absolutely authentic references to these can be obtained,
and the date of the first actual discovery of gold in this country must
Temain shrouded in uncertainty.
Jefferson, in his Notes on Virginia (1782), mentions the discovery of
.a nugget containing 17 dwts. "of gold four miles below the falls of the
Rappahannock river. The U. S. Mint reports give the first returns from
Virginia in 1829. For North Carolina the first mint returns appear in
1793; but the first mention of any specific find of gold in North Caro-
lina is of a 17-pound nugget, discovered on the Reed plantation in
Cabarrus county, in 1799.
Mills, in his Statistics of South Carolina, notes the occurrence of
gold in Abbeville and Spartanburg districts as early as 1826, but the
first U. S. mint returns from this State are given in 1S29.
The gold placers in Burke and McDowell counties, North Carolina,
(South Mountain belt) were first worked in 1829, and immediately
traced southwestward through South Carolina into Georgia.
John Witheroods, of North Carolina, claims to have first discovered
gold in Georgia in 1829 at Duke's creek, near Nacoochee, Habersham
county;3 but Jesse Hogan, also of North Carolina, claims to have taken
1 We are indebted to Mr. Geo. R. Hanna, of the Charlotte Assay office, for valuable notes re
lating to the History of Mining and Metal] urg-ical Operations in North Carolina.
2 Sixteenth Annual Report of the 77. S. Geological Survey, part iii, 1894-5.
3 Now in White county, which was later formed from a part of Habersham.
3 feibrarifi
HISTORICAL NOTES : MINING, METALLURGICAL AND STATISTICAL. 2 <
out gold previously in a branch of Ward's creek near Dahlonega, which
was then in the " Cherokee Nation." The earliest mint returns from
Georgia appear in 1830.
Dr. Wm. B. Phillips * gives 1830 as the probable approximate date
of the first discovery of gold in Alabama. There were, however, no
mint returns from this State until 1840.
Perhaps one of the chief reasons that the discovery of gold came
so much later in Georgia and Alabama than it did in North Carolina
and Virginia, was that this part of the country was then occupied by
the Cherokee Indian Nation, under the supervision of the United States,
and was not open to white settlers, although the latter repeatedly in-
truded.
After the discovery of gold, the long pending efforts of the States
to acquire these Indian lands were stimulated and accelerated by the
added thirst for the precious metal, and were finally successful in 1830,
when the State laws were extended over the Nation and the Indians
were removed. The mining region in Georgia was surveyed into 40-acre
lots, which were distributed by lottery. A caustic writer of the time
says that, " intrusive mining ceased then and there, and swindling min-
ing commenced."
The first mention of gold in Tennessee is from Coco creek, Monroe
county, in 1831,2 and this date corresponds with that of the first mint
receipts.
The earliest record of gold in Maryland is in 1849,3 from the farm of
Mr. Samuel Ellicott in Montgomery county, about 12 miles north of
Washington, where a depth of 50 feet was said to have been reached,
and about $3000 in gold to have been taken out. The mint reports,
however, show no returns previous to 1868.
EARLY MINING OPERATIONS.
The greatest activity of gold mining in the South seems to have fol-
lowed closely on the first discovery, being most marked from 1829 to
1836, and probably due to the working of the more accessible virgin
placers and more easily mined outcrops. The mint receipts show a
renewed activity from 1839 to 1849, caused perhaps by more syste-
matic vein explorations and improved methods. In the early fifties, the
Californian discoveries abated the interest in the Southern gold field, and
attracted the mining population westward, causing a natural depression
in the output; from that time on there was a general decrease until the
1 Geological Survey of Ala., Bull. No. 3, 1892, p. 10.
2 Safford's Geology of Tenn., 1869, p. 490.
3 Emmons, E., Proceedings of the American Philosophical Society, 1849, Vol. v., p. 85; see also
Am. Jour. Sci., Vol. xvii, 1830, p. 202.
L',S GOLD MINING IN NORTH CAROLINA.
practically total cessation caused "by the Civil "War. Since then there
have been spasmodic revivals and depressions, due undoubtedly in a
great measure to local causes and excitements, and to the financial con-
dition of the country at large. Considering the small total output of
the South, such fluctuations may have been caused by the successful
working of a single mine, shown for instance, by the increased produc-
tion of South Carolina since 1890, owing to the revival of the Haile
mine.
The first practical, systematic mining operations appear to have been
in North Carolina, beginning about the year 1800. Prom 1804 to
1827 (inclusive) this State furnished all of the gold produced in the
country, amounting to $110,000. The progress up to 1820 was very
slow, and mining was restricted to a very limited area. Prof. Olrn-
stead, the first State Geologist of North Carolina, in his writings,1 esti-
mated the extent of the then known gold country at 1000 square miles.
He says: " The gold country is spread over a space of not less than 1000
square miles. With a map of North Carolina, one may easily trace
its boundaries, so far as they have been hitherto observed. From a
point taken eight miles west by south of the mouth of the Uwharie,
with a radius of eighteen miles, describe a circle; it will include the
greatest part of the county of Montgomery, the northern part of Anson,
the northeastern corner of Mecklenburg, Cabarrus — a little beyond
Concord on the west — and a corner of Rowan, and of Randolph. In
almost every part of this region gold may be found in greater or less
abundance at or near the surface of the ground. Its true bed, how-
ever, is a thin stratum of gravel enclosed in a dense mud, usually of a
pale blue, but sometimes of a yellowish color. . . . Rocky river and its
small tributaries, which cut through this stratum, have hitherto proved
the most fruitful localities of the precious metals."
In 1820 articles began to appear in the public journals calling atten-
tion to the North Carolina gold deposits, and itinerant German miners
and mineralogists had already come into the country in some number.
In 1821, when Olmstead wrote, there was a considerable mining popu-
lation, whose average earnings were from 60 to 65 cents per day
(approximately 65 to 70 cents in the present standard of gold coinage).
The toll paid to the owners of the land varied from one-fourth to occa-
sionally one-half of the yield. The dust came to Be quite a medium of
circulation, and miners were accustomed to carry about with them quills
filled with gold, and a pair of small hand-scales, on which they weighed
out gold at regular rates, (for instance, 3^ grains of gold was the cus-
tomary equivalent of a pint of whiskey). The gold found its way largely
1Am. Jour. ScL, 1825.
I
HISTORICAL NOTES! MINING, METALLURGICAL AND STATISTICAL. 29
into the country stores in exchange for merchandise at the rate of 90
to 91 cents per pennyweight (96 to 97 cents present standard).
In these early days farming and gold digging went, in many cases,
hand in hand; and this is indeed still true, to some extent, at the present
day. When the crops were laid by, the slaves and farm hands were
turned into the creek-bottoms, thus utilizing their time during the dull
seasons. Where mining proved more profitable than planting, the for-
mer superseded the latter entirely. Thus, in speaking of the Tinder
Mats placer in Louisa county, Va., Silliman says:1
" Jenkins is in the habit of substituting a fall working in the gold,
for which he obtains $1000 annually, as a compensation for his tobacco
crop, which he relinquishes in favor of the gold."
Some of the more prominent localities developed into regular mining
camps, where continuous and extensive operations were carried on.
Such were, for instance, Arbacoochee and Goldville, Ala.; Auraria and
Dahlonega, Ga.; and Gold Hill and Brindletown, ~N. C. In the latter
place it is stated that just before the California excitement as many
as 3000 hands might have been seen at work on one of the streams of
the region.'2 In 1853 there was a population of about 2000 in the Gold
Hill camp.
When Lumpkin county, Ga., was organized in 1832, Dahlonega (then
called New Mexico) had a population of 800. During the mining
boom Dahlonega had a population of 5000, and Auraria (then called
Knucklesville) 2000 to 3000.3
At Goldville, Ala., between 1840 and 1850, there was a population
of at least 3000.
The first work, naturally, was the washing of the stream placers.
After these were exhausted, attention was turned to the gravel deposits
lying under cover of the alluvium. These were Avorked by sinking pits,
and raising the gravel by hand labor. Where it was necessary the
pits were drained by large vertical bucket-wheels, for which the power
was derived from the stream directly, or by flume lines with over-shot
or under-shot wheels.
EARLY MINING AND METALLURGICAL METHODS.
The first primitive washing, as in other newly discovered gold coun-
tries, was probably done with the pan. As the workings grew more
extensive, this was superseded by the rocker, long torn and sluice-box;
and, indeed, these original devices survive to the present day.
1Eeport to the President and Directors of the Walton Mining Company. By Prof. B. Silliman,
Jr., Fredericksburg-, Va., 1836.
2 Ores of North Carolina, 1887, p. 312.
3 Recollections of A. G. Wimpy (a very old citizen of Dahlonega, Ga.) published in the Dah-
lonega Signal, Aug. 20, 1883.
30 GOLD MINING IN NORTH CAROLINA.
The rockers in use to-day are of two types. The first is essentially
a panning process, nsing a minimum amount of water, the operation
being an intermittent one. This type of rocker is closed at both ends,
the discharge being over the side; it will be described, with illustrations,
as now in use at the Crawford mine (p. 94). The second type con-
sists of a hollow segment of a log closed at the upper end. It is set
on a slight inclination, about 6 inches in 10 feet, and is provided at the
lower end with grooves or strips that act as mercury pockets or riffles.
When used on gravel it is provided at the upper end with a shallow
box having a round punched or slotted iron bottom. The length of
this type of rocker is 5 to 10 feet. The gravel and clay are thrown
into the box, where a constant stream of water, together with the rock-
ing motion and stirring with fork or shovel, disintegrates the material.
The pebbles and bowlders are thrown out with the fork, while the fine
portions are washed down the bottom. The rocking facilitates the
settling and amalgamation of the gold and the discharge of the tailings.
Two men work at one rocker or set of rockers, so joined together as to
move in harmony. One throws the gravel from the pit into the box,,
or directly into the rockers, and the other sits or stands above the rock-
ers moving them with his feet, disintegrating the gravel with a fork
and discharging the coarse material. Rockers of a similar type are at
present in use at several mills for handling pulp and blanket washings.
(See Plate I.)
AVhere sufficient flowing water is at hand, the sluice box and long
torn are used, as they handle larger quantities with less labor. The
sluice box, generally 8 to 10 feet long, 20 inches wide and 12 inches
deep, provided with riffles and a perforated charging plate at the head,
fulfils the same purpose as the rocker; being stationary, however, it
requires a larger amount of water to carry off the tailings.
It is interesting to note that at the Beaver Dam mine, in Mont-
gomery county, N". C, a large rocker, about 10 feet long by 3 feet wide,.
was operated as early as 1825 by steam power, the engine having been
imported from England.
Tuomey,1 in 1854, mentions ground-sluicing of side-hill deposits at
Arbacoochee, Ala., by aid of a ditch and a series of trenches into which
quicksilver was poured. It is probable that this method of working
existed even prior to that day.
HYDRAULIC METHODS.
The first use of the hydraulic method of mining was probably early
in the forties, previous to the California gold discoveries, in the west-
ern part of Xorth Carolina, although on a much smaller and modified
1 Second Biennial Report on the Geology of Alabama, p. 70, Montgomery, 185$.
N. C. GEOLOGICAL SURVEY.
BULLETIN 10, PLATE I.
1F7~
LOG ROCKERS, GOLD HILL, N. C.
A small stream of water pours from the crude V-shaped trough above into the upper end of each
of the larger troughs below, and washes the gravel and soil out at their lower ends.
'See also p. 60.)
CHILIAN DRAG-MILL AND ROCKERS, NEAR GOLD HILL, N. C.
(See page 33.)
II
HISTORICAL NOTES! MINING, METALLURGICAL AND STATISTICAL. 31
scale as compared to its present application. Mr. Wm. H. Ellet, writ-
ing in the Mining and Statistic Magazine 1 early in 1858, in reply to
Hon. T. L. Clingman's inquiry of December, 1857, says:
" I avail myself of my earliest leisure to answer your inquiries in relation to
the hydraulic gold-mining operations lately introduced by Dr. M. H. Vandyke,
in some of the western counties of North Carolina My observations in the
hydraulic process were made during the month of April 3 at the Jamestown
mine,3 in McDowell county, N. C. The water was there conveyed .... about 4
miles. The uniform descent was 4 inches to the hundred feet The number
of hose pipes employed was four. The mass of earth moved in nine working
days was 20 feet in depth, 82 in length and 26 in breadth, being at the rate
of 1184 cubic feet, or 966 bushels, per day for each hose The labor
employed .... was that of four men and two boys The yield in gold
was $5.13 per day for each hose employed.
Shortly afterwards a further publication appeared in the same mag-
azine,4 from which the following extracts are taken:
" The Wilkinson gold mine in Burke county, N. C, is owned by Dr. Van Dyke,
and is worked by the hydraulic process. The water is brought .... by a
canal or aqueduct for a distance of 15 miles The water is not brought
upon these mines at a very high head, only about 40 feet. There was only one
pipe in operation at the time of my visit. The water passed through a 6-inch
hose and a nozzle of iy2 inches The average yield of the mine .... was
about $5.00 a day to each hand Obtaining a sample of the gold of this
mine, we passed over about 2 miles to the Bunker Hill mine, also in Burke
county. This was formerly known as the Brindleton mine. It is owned and
worked by Rev. Benjamin Hamilton It is now worked by the hydraulic
process T> amount of water is limited, sufficient only for about two
pipes, which is brought in a small ditch for a distance of 4 or 5 miles
The Collins mine in Rutherford county is owned and worked by Dr. Van
Dyke. The water is brought to this mine in a canal about 4 miles in length,
at an elevation of 150 feet, and sufficient in amount for 20 pipes, and will
command nearly 1000 acres of surface Jamestown mine, McDowell
county, N. C, [is] also worked by Dr. Van Dyke. The deposit workings embrace
about 400 acres. The water is brought by a canal at an elevation of 70 feetr
and is five miles in length. There is water enough here for 20 hose pipes."
Prof. Wm. P. Blake (in 1858) in a " Keport upon the Gold Placers of
Lumpkin county, Georgia, and the Practicability of Working them by
the Hydraulic Method, with Water from the Chestatee River,"5 says:
" Desiring to see the results obtained [by Dr. M. H. Van Dyke] in North
Carolina, and thus to be enabled to form a better judgment of the probable
results in Georgia, I first visited the placers in Burke and McDowell counties
1 Vol. x, pp. 27-30, January 1858. Our attention was called to this and related articles by the
interesting- paper of Prof. Wm. P. Blake, published in the Transactions of the America)! F»sti-
tute of Mining Engineers, October 1895, entitled Notes and Recollections Concerning tli<- Min
eral Resources of Northern Georgia and Western North Carolina.
- 1857.
3 Afterwards and at present known as the Vein Mountain mine.
4 Vol. x, pp. 393, 394, May, 1858.
5 Mining and Statistic Magazine, vol. x, pp. 457-476, June, 1858.
32 GOLD MINING IN NORTH CAROLINA.
where the [hydraulic] process is now in successful operation The average
yield, as shown by the results at several of the North Carolina placers, is about
$6.00 a day to a pipe attended by two men, or by a man and a boy. At
some of the placers the average is not less than §10.00 a day At Brin-
dletown, in the bed of a little brook which has a rapid descent, Mr. Hamilton
has been washing very successfully with two pipes and five men and boys
I am confident that the yield cannot be less than $20.00 a day, even among
the former excavations where the gravel has been washed over more than
once before."
Lieber1 mentions the hydraulic process as being practiced previous
to 1859 at Pilot mountain in Burke County, X. C, and he evidently
has reference to the above described localities.
The Dahlonega method (a combination of hydraulicking, sluicing and
milling) originated in 1868.
The first record that we have of dredge mining is that carried on by
a Mr. Gibson in 1843-4, in the Catawba river, Gaston county, X. C.
The river sediments and gravel were scooped out on flatboats by men
using long-handled scoops, and the material was carried ashore and
washed.
Later on mechanical dredges of various designs came into use,
chiefly on the Chestatee river, in Georgia.
The advent of the hydraulic gravel elevator dates from about 1883.
It was 'first applied at Brindletown, N". C, and at Dahlonega, Ga. The
well-known type of this mechanism, known as the Hendy lift, was
employed at the Cincinnati Consolidated Company's mines in Dawson
county, Ga., in 1SS3. The plan was to divert the Etowah river and
to suck up the gravel from the old channel.
The Roy Stone method" was experimented with in the Chestatee
river in 1883, but the results are not known.
The Crandall hydraulic elevator,3 as used at the Chestatee mine,
Georgia, in 1895, contains important improvements over other types of
similar mechanisms.
VEIN MINING. FREE-MILLING ORES.
Yein mining probably followed more or less closely on the exhaus-
tion of the richer gravel deposits. The first account of vein mining is
in 1825, at the Barringer mine, Stanly4 county, !N\ C. In Virginia
the veins of the Tellurium and Yaucluse mines were discovered in 1832;
and in Georgia the Reynolds vein, lot IsTo. 10, near !N"acoochee, in
White county, was discovered some time prior to 1834.
1 Supplementary Report to the Survey of South Carolina, 1S59, p. 154.
2 Trans. Amer. Inst. Min. Eng., vol. viii, p. 254.
3 Ibid., vol. xxvi, 1897, pp. 62-68.
4 This part of Stanly was then a part of Montgomery county.
HISTORICAL NOTES: MINING, METALLURGICAL AND STATISTICAL. 33
EARLY MILLING APPLIANCES.
For a long time the output was confined to the free-milling brown
ores near the surface, and the ore was raised by horse-whim and hand-
windlass, or even by baskets carried upon the backs of the miners. At
first the gold from the ores of the decomposed outcrops of the veins
was extracted by washing in rockers. The following quotation from
Prof. Elisha Mitchell's Report on the Geology of North Carolina (1827),
is pertinent here :
" The quartz is raised from the mine, broken to pieces, and those parts
which are known to contain gold selected for washing. This part of the
process is conducted in the same way as in Montgomery (county), except that
the agitation is continued for a longer time, and that a small quantity of
quicksilver is put into the rockers to collect the gold, by forming an amalgam
with it."
The most primitive method of milling the quartz was undoubtedly
by crushing in hand-mortars and subsequent panning. This is still
carried on by the native tributors in certain districts. It was followed
by the introduction of the drag mill {arr astro), the Chilean mill (Plate
I, p. 30) and eventually the stamp-mill. The two former were evidently
drawn from South American and Mexican practice, and were probably
the first mechanical pulverizing machinery used.
As an illustration of some of the earlier milling methods, the f ollowT-
ing is taken from a report of the Supervising Committee of the United
States Mining Company in 1835, on their mine near the Rappahannock
river, Virginia:
" The plant consists of a crushing (rolls) and a vertical mill (stamping-mill) in
a building 26x36 feet. Both mills are located on the ground floor and are
propelled by a water-wheel 11 feet in diameter, with a 11-foot face. The
crushing-mill has 3 sets of cylinders 2 feet in length and 15 inches in diameter,
the first or upper set fluted, the other smooth. The ore is thrown into a hopper
on the upper floor, from which it is conducted over an inclined shaking-table
to the fluted cylinders, by which it is crushed to a size from 14 to 1 inch in
diameter. The crushed material is equally divided and goes to the two sets
of smooth cylinders. By them it is further greatly reduced, ranging from
impalpable powder to grains as large as coarse hominy. From these cylinders
it falls into a sifter having the fineness and motion of the common meal-sifter,
from whence the material which passes through is conducted to 12 amalga-
mators, constructed upon the principle of the Tyrolese bowls, making from 90
to 100 revolutions per minute. They perform the office of washing and amalga-
mating. The sand discarded by them, after being washed, is conducted through
troughs to the vertical mill, where, being reduced to an impalpable powder, it
passes in the shape of turbid or muddy water to another set of amalgamators
similar to those above mentioned, and thence to the river. The portion of the
ore reduced by the cylinders which passes over the sifters is conducted to the
vertical mill, and is treated in the same manner."
34 GOLD MINING IN NORTH CAROLINA.
The process at another Virginia mine, the Vaucluse, is described ' in
1847 as follows:
" The machinery consists of a condensing Cornish mining engine of 120 horse-
power; the mill-house contains 6 large Chilean mills; the cast-iron bed-plate of
each is 5 feet 6 inches in diameter, and on it are two cast-iron runners of the
same diameter, the total weight of the mill being 6200 pounds. The ores, on
arriving at the surface, are divided into two classes: 1. The coarse and hard
ore for the stamps; 2. Slate and fine ore for the Chilean mills. This is done by
means of a large screen. The very large pieces are first broken by a hammer
before they are fed to the stamps. All of the ores are ground with water, each
mill being supplied with hot and cold water at pleasure. Twelve inches from
the top of the bed-plate there is a wide, open mouth, from which the turbid
water escapes to tanks. On the south side of the steam-engine is the stamp
house and amalgamation mill, containing 6 batteries of 3 stamps each; these
stamps, with the iron head of 125 pounds, weigh 350 to 380 pounds each. Each
battery is supplied with water, and at each blow of the stamp a portion of the
fine ore passes out of the boxes through the grates to the amalgamation room.
Here are stationed 18 small amalgamation bowls of cast iron. 30 inches in diam-
eter. The bowls are supplied with runners which move horizontally: in the
center of these runners is an eye or opening like that in the runner of a corn-
mill. The ground or finely-stamped ore, gold and water pass into this eye. and
by the rotary motion of the same are brought into contact with the quicksilver
deposited in the center, forming amalgam. From the amalgamators the pulp
passes through 3 dolly-tubs or catch-alls, acting as mercury and gold tubs. After
this the whole mass passes to the strakes or inclined planes, where The sul-
phurets are deposited and the earthy matter washed away. These sulphurets
were formerly treated in two heavy Mexican drags or arrastras; but not answer-
ing so good a purpose, they have been altered into three heavy Chilean mills.""
The collection of amalgam, retorting and melting was practically the
same as to-day. The total plant at this mine was valued at $70,000.
Emmons gives the method of working the ores of Gold Hill, X. C.r
in the earlier days as follows : "
" The machinery employed at Gold Hill for separating gold, consists, first of
the Chilean mill for crushing and grinding, after being broken by hammers,
the Tyrolese bowls, the Burke rockers, and the drag-mill The work for
a Chilean mill of this ore is 70 bushels per day, and our mills run for 24 hours,
with one or two short interruptions. They are all moved by steam-power, and
all the water used in the mills is pumped from the mine. The Burke rocker
is the principal and best saving machine employed. The drag-mill is also a
good machine, is cheap, and easily kept in repair. On inspecting these opera-
tions when going on it is impossible to resist the conclusion that much of the
gold is wasted along with the mercury."
Emmons further states the force employed at Gold Hill at that time
for working the Earnhardt (Randolph) vein to consist of:
" 66 miners paid by the month and 39 negroes hired by the year. The day
of 24 hours is divided into three shifts of eight hours each for underground
work."
1 Plan and Description of the Vaucluse Mine, Orange County, Va. Philadelphia, 1S47.
2 Geological Report of the Midland Counties of North Carolina, 1S56. E. Emmons, pp. 160et8€9.
1
HISTORICAL NOTES! MINING, METALLURGICAL AND STATISTICAL. 6b
The stamp-mill, or, as it was originally called, the " pounding mill,"
was most probably a European innovation. As early as 1836 a 6-stamp
mill, with 50-pound stamps, was in operation at the Tellurium mine in
Virginia. In 1837 a Frenchman erected a mill at the Haile mine in
South Carolina. These primitive mills were constructed of wood, with
iron shoes and die-plates; the general type of construction was similar
to that of the present California mills, with the exception that the
stems were square and did not revolve, the cams working in slots or
recesses cut into the stems. A few of these old-fashioned mills may
still be seen in operation in Georgia in the Nacoochee valley, seemingly
serving the purpose of the tributors and petty quartz miners, and it is
stated that they are operated at a fair profit. They are cheaply con-
structed, a 10-stamp mill with water-wheel and building complete
costing about $150. The amalgamation is done on a copper plate of
the width of the battery and about one foot long.
The first regular California battery was erected at the Kings moun-
ain mine, in North. Carolina, just after the war; and in 1866 a similar
mill was built at the Singleton mine, in Georgia, by Dr. Hamilton.
Besides mills of "Western manufacture, there are two types which
are common to the South. One of these is an excellent 750-pound mill
built by the Mecklenburg Iron Works of Charlotte, N". C, a slight
variation of the Western type (described on p. 119). The other is the
450-pound Hall mill, which is peculiarly adapted to the saprolitic ores
of the Dahlonega district in Georgia (described on pp. 110—113.)
Various types of rotary pulverizers and pan amalgamators have been
introduced in the South from time to time, supposedly as improvements
on the stamp-mill, as, for instance, the Tlowland mill, a flat circular
disc revolving in an iron shell; and, similarly, the Crawford (with
revolving iron balls) and the Huntington mills; the Parson mill, not
unlike the Howland, but covered with a hood, and having the interior
grinding surfaces coated with lead-amalgam; the Meech mill, in which
the quicksilver was comminuted by superheated steam; the Wiswell
mill, being practically an iron Chilean mill fed with corrosive sub-
limate in connection with an electric current; the Nobles process, in
which the ore was ground to 100-mesh between buhr-stones and the
pulp run over amalgamated slabs of zinc or lead. Revolving Freiberg
barrels were also used at some of the mines. The Blake system of fine
crushing, combined with subsequent wet grinding,1 was introduced at
the Haile mine in 1884, but was soon abandoned in favor of the
present stamp-mill.
The above are simply cited as a few examples of the vast number of
mechanical appliances for grinding and amalgamation with which the
1 Trans. Amer. Inst. Mining Evaincers, vol. xvi, p. 7.V>.
36 GOLD MINING IN NORTH CAROLINA.
mines of the Southern States have been overrun. Although some of
these, notably the Huntington mill, are still in use at a few places, it
has been quite clearly demonstrated that such grinding apparatus pro-
duces float gold and flours the quicksilver, besides which the mechan-
ism is subjected to great strain and wear, against all of which defects the
stamp battery, with plate amalgamation, has proven itself vastly su-
perior, and through all of its vicissitudes it has held the field as the
most economical and rational apparatus for milling and amalgamating
gold ores.
TREATMENT OF SULPHURET ORES.
As soon as the water-level was reached in the mines, and the free-
milling brown ores were practically exhausted, attempts were made to
treat the undecomposed sulphurets.
MECHANICAL METHODS.
Probably the earliest method employed for the concentration of these
sulphurets was that used at the Yaucluse mine in 1847 (described on
page 34), which consisted in passing the material over strakes or in-
clined planes. This was probably followed by buddies, primitive bump-
ing-tables and more especially by blankets. Log rockers were also
used at an early date for this purpose. At the present day the Frue,
Embrey and Triumph concentrators are in general use. Of these, the
Embrey machine is considered by some to give better results, especially
where skilled labor cannot be obtained, and where the sulphurets are
not sized. Still, each one of the three finds its strong advocates, and the
difference in perfection of concentration obtained by them is prob-
ably not material. In some cases — as, for instance, in the Gold Hill
district — the finely-divided condition of the gold has led to the re-em-
ployment of blankets.
At the Reimer mine, North Carolina, a plant was in operation in
1883 in which the ore was comminuted in a series of crushers and 26-
inch rolls; the pulp was sized into six grades, from 10- to 60-inesh, and
each grade treated separately by a Bradford jig. This process is said
to have given good results, but the plant was destroyed by tire soon
after its erection and never rebuilt. The same system of jigging was
at one time in use at the McGinn mine in North Carolina.
The earliest treatment of the concentrated sulphurets was by regrind-
ing them (in the raw, unroasted state) in Mexican arrastras and Chilean
mills, with subsequent amalgamation, as described above in the prac-
tice of working the ores at the Yaucluse mine, Virginia, in 1847.
In 1852-53, a Dr. Holland, of Massachusetts, introduced a roasting
process at some mines near Charlotte, IsT. C, in which the pyritic con-
HISTORICAL NOTES! MINING, METALLURGICAL AND STATISTICAL. 37
centrales were mixed with nitrate of potash or soda and roasted in a
reverberatory furnace at a low heat.
Lieber stated 1 in 1856 that a process for roasting sulphurets, with sub-
sequent amalgamation, had been introduced by a Mr. C. Bingel at a
mine near Rutherfordton, ~N. C. (this was probably the Alta mine),
and was afterwards practiced with success on old tailings at the Gold
Hill and other mines in North Carolina.
In the past history of the Southern mines a vast number of roasting
processes and furnaces have been introduced, many of them approach-
ing the ludicrous, but they have never lasted beyond the experimental
stage. Heap-roasting with salt was also tried.
Some of the furnaces, particularly of the well-known reverberatory
type, were successful enough so far as the roasting went; the fault lay in
the prevalent and popular belief that, by oxidizing the sulphurets, the
difficulty of amalgamating the precious metals, which had been set
free, would be removed, when in fact the resulting coating of iron oxide
was nearly as fatal to the work as the sulphide had been.
The Bartlett method of making white lead-zinc oxide was introduced
at the Silver Hill mine, North Carolina, in 1871-2. It consisted in
roasting the concentrated galena-blende and condensing the zinc-lead
oxide fumes, which made a good paint material. The process is said
to have been carried on successfully until all the available suitable ma-
terial was exhausted.
CHEMICAL TREATMENT.
The next step was in the direction of a chemical treatment of these
refractory sulphurets. It would be useless to outline the numerous
processes that were experimented with for this purpose. The South
has been, much to its detriment, the " proving ground " of almost all
the patent gold-saving processes invented, and the greater proportion of
these have, as might have been predicted, resulted in utter failure.
Of all these the chlorination process is practically the only survivor;
and there is a possibility of the successful application of the cyanide
process.
THE CHLORINATION PROCESS.
It was not until 1879 that the successful treatment of pyritic sul-
phurets was accomplished by the introduction of the chlorination pro-
cess. In that year a Hears chlorination plant was erected at the
Phoenix mine, North Carolina, under the management of Mr. A. Thies,
who soon improved on and developed it into what is now universally
known as the Thies process.
1 Report on the Survey of South Carolina for 1856, p. 47.
38 GOLD MINING IN NOKTH CAROLINA.
Iii 1880 a chlorination plant (the Davis and Tyson Metallurgical
Works) was erected two miles south of Salisbury, X. C. The process
used was known as the Davis process, which differed from the Clears
only in the method of precipitating the gold with charcoal instead of
ferrous sulphate. These works were in spasmodic operation on cus-
tom ores for several years.
In 1881 a Davis plant was erected at the Reimer mine, Xorth Caro-
lina, but was shortly burned down, before thorough testing.
In 1882 the Plattner chlorination process was introduced at the
Tucker mine, North Carolina, but was not successful, and in the fol-
lowing year the Mears process was substituted, which also had a short
existence here. These failures were, however, most probably due to
the impracticable application of the methods rather than to the char-
acter of the methods themselves.
Experiments were made several years ago by Mr. P. G. Lidner at the
Brewer mine in South Carolina, and at Dahlonega, Ga., with a chlor-
ination process for treating the ore in bulk; and a plant for a patent
electrolytic-chlorination process was erected in 1895 at the Clopton
mine, Villa Rica, Ga. None of these have, however, met with prac-
tical success.
At the present time the Thies process is in successful use at the
Haile mine, South Carolina, and the Franklin and Royal mines, Georgia.
THE CYANIDE PROCESS.
The cyanide process has so far found but little application in the
South. In May, 1892, Mr. Richard Eames, of Salisbury, X. C, ex-
perimented with cyanide at the Gold Hill mine, 1ST. C, extracting 60
per cent of the assay value. In the summer of 1893, a 10-ton cyanide
plant was working at the Moratock mine, 1ST. G, but the operations
were soon relinquished here on account of the low grade and character
of the ore. Later in the same year, a cyanide plant was in operation at
the Gilmer mines in Goochland county, Ya. ; with what success could
not be ascertained. At the Franklin mine, Ga., a treatment of the
ores with cyanide was attempted before the introduction of the chlor-
ination process. It proved successful on the oxidized tailings from the
old dumps; but the extraction from fresh sulphurets was insufficient to
warrant its continuation.
In 1895 cyanide experiments were made at the Sawyer mine, in Ran-
dolph county, 1ST. C, but were soon abandoned. In 1896 a 30-ton
cyanide plant was erected at the Russell mine, N. C, by the American
Cyanide Gold and Silver Recovery Company of Denver, Col., and a
small plant was also built at the Cabin Creek (Burns) mine, X. C, by
the same company, but neither of these lias yet been put in practical
operation.
!l
HISTORICAL NOTES: MINING, METALLURGICAL AND STATISTICAL. 39
OTHER CHEMICAL PROCESSES.
The Hunt and Douglas process was successfully applied in IS 80 to
the ores of the Conrad Hill mine, N. C. The roasted snlphurets were
leached with a ferrous chloride solution, converting the copper to a
soluble chloride, from which it was precipitated as metallic cement on
scrap iron.
The Designolle process, which consisted in treating the roasted ore
with corrosive sublimate in iron vessels, was only moderately successful
in its application, for the reason that it made a very base bullion, the
iron of the apparatus invariably precipitating any soluble salts formed
in the roasting. It was worked for a time, during 3 882-83, at a custom
plant near Charlotte, N. C. ; at the New Discovery mine, Rowan county,
N. C. (1883), and at the Haile mine,1 S. C. (1883).
A plant for the extraction of gold from pyritic concentrates, with the
recovery of the sulphuric acid, was erected early in the present decade
at Blacksburg, S. C, mainly for the treatment of custom ores. The
concentrates were roasted in a Walker-Carter muffle furnace, which
was connected with lead chambers. The amalgamation of the roasted
product Avas carried on by a patent process known as the Caloric Reduc-
tion Company's process, the principle of which was a. volatilization of
mercury into the mass of the pulp, followed by a condensation of the
same, the amalgam being led into settling vats. It was proposed to use
the tailing residues for the manufacture of red paint. The scheme, as
might have been predicted, was a failure. A similar process, known
as the Phelps process, had already been unsuccessfully tried on North
Carolina ores, in (about) 1877, in an experimental plant situated at
Philadelphia.
Attempts at pyritic smelting were made as early as 1847 at the Vau-
cluse mine in Virginia by Commodore Stockton, but resulted in failure.
Matte smelting, followed by refining in reverberatory furnaces,
was practiced (about 1881-1882) on the copper ores of the Conrad Hill
and the North State mines in North Carolina.
Experiments on matting auriferous sulphurets from the Haile mine,
S. C, were made in 1886 by Mr. E. G. Spilsbury," but proved unsuc-
cessful.
Regarding smelting processes in the South, probably most has been
done in the attempted treatment of the complex galena-blende ares,
carrying silver and gold, of the Silver Hill and Silver Valley mines,
Davidson county, N. C.
The process in use at Silver Hill, as early as 1S53, was heap-roasting,
followed by wet-crushing in a stamp battery, the zinc oxide being dis-
1 Trans. Amer. Inst. Min. Enps., vol. xv, p. 771.
2 Trans. Amer. [nst. Min. Eiig*., vol. xv, pp. 7(57-77").
40
GOLD MINING IN NORTH CAROLINA.
solved and recovered separately, after which the residues were smelted
in the old-fashioned Scotch open-hearth lead furnace, and the precious
metals were recovered from the pig lead by refining in a cupellation
furnace.1
During the past twelve years a number of patent processes have been
experimentally tried on the Silver Valley ores in a plant situated at
Thomasville, ~H. C, but it was not until 1895 Jhat a successful process
was introduced by Mr. Mninger, of Newark, X. J. It consists of a
down-draught jacket furnace, through which the fumes of lead and
zinc are carried downward into condensers, where they are met by a
spray of water, the liquor being led to vats where the lead oxide is
deposited, while the zinc remains in solution and is subsequently pre-
cipitated as zinc oxide. The matte, carrying copper, gold and most
of the silver, is tapped from the well of the furnace and cast into pigs.
PRODUCTION OF GOLD AND SILVER IN NORTH CAROLINA AND
OTHER SOUTHERN STATES.
The following table, compiled from the production reports of the
United States Mint, gives an estimate of the gold and silver production
of the Southern States down to the present time. The figures represent
not only the amounts deposited at the United States Mint and Assay
Offices, but also such amounts that were produced and not turned into
the mint and of which records could be obtained:
Table I. — Estimate of the Production of Gold and Silver in each of the
Southern States from 1799 to 1879 and Annually Since.
Year.
Md.
Va.
N. C.
S. C.
Ga.
Ala.
Term.
Total.
1799-1879
$2,500
$3,091,700
$19,659,600
$2,587,900
$14,180,500
$365,300
$155,300
£40,042. N 0
1880...
250
11,500
95,000
15,000
120,000
1,000
1.500
244.250
1881 ....
500
10,000
115.000
40,000
125,000
1,000
1,750
293,250
1883....
1,000
15,000
215,000
25,000
250,000
3,500
250
509. Toil
1883....
500
7,000
170,000
57,000
200,000
6,000
750
441,250
1884....
500
2,500
160,500
57,500
137,000
5,000
300
36o.o(iii
1885....
2,000
3,500
155,000
43,000
136,000
6,000
300
345.800
1886....
1.000
4,000
178,000
38,000
153,500
4,000
500
379.1 1 0
1887...
500
14,600
230,000
50.500
110,500
2,500
500
409.100
1888 ...
3,500
7,500
139,500
39,200
104,500
5,600
1.100
300.POO
1889....
3,500
4,113
150,174
47,085
108,069
2,639
750
3U5.830
1890 ....
16,962
6,496
126,397
100,294
101,318
2,170
1,001
354.t-:38
1891...
11,264
6,699
101,477
130.149
80,622
2,245
519
332.975
1892....
1,000
5,002
90,196
123.881
95,251
2,419
1,006
318,755
1893 ....
114
6,190
70,505
127,991
100,375
6,362
250
311.787
1891 ..
978
7,643
52,927
98,763
99,095
4,092
329
263.827
1895...
501
6,325
69,196
12S.303
128,403
4,708
335
337.771
1896....
1.037
4.466
52.056
100,711
$3,810,277
150,085
6,695
58J
315.632
Total..
$47,606
$3,214,234
$21,830,528
$16,380,218
431.230
$167,022
$45,881,115
In order to give an idea of the fluctuation from 1799 to 1896, Table
Xo. 2 is given. These figures, however, comprise only the actual
1 Mining Magazine, vol. i, 1853, p. 367 et scq.
HISTORICAL NOTES: MINING, METALLURGICAL AND STATISTICAL. 41
United States Mint and Assay Office receipts, and do not include such
bullion as went abroad, was sold directly to local jewellers, or was coined
by the Bechlters * at Kutherf ordton, K C.
Table II.-
Statement of
Gold and Sil
ver prod
ern States
• / Deposited at the United States a
to 1896 inclusive.
Year.
Amount.
Year.
Amount
1793-1S23
$47,000
1848
$850,692
1S24
5,000
1849
891,968
1S25
17,000
1S50
658,605
1S26
20,000
1S51
500,539
1827
21,000
1S52
711,449
1S28
46,000
1S53
486,184
1829
140,000
1854
323,489
1S30
466,000
1855
362,349
1S31
519,000
1856
325,820
1832
678,000
1S57
141,810
1S33
868,000
1858
349,323
1834
898,000
1859
379,677
1S35
6S6,300
1860 .
231,398
1S36
667,000
1861
141,778
1S37
282,000
1862
6,298
1S3S 2
35S,750
1S63
1,624
1S39
429,648
1864
6,093
1S40
427,311
1865
33,345
1S41
544,661
1866
202,000
1S42
723,761
1867
106,903
1S43
1,050,100
1S6S
155,660
1844
928,095
1869
191,738
1S45
986,849
1870
168,057
1S46
992,792
1871
138,791
1S47
1,018,079
1872
164,461
Year.
Amount.
1S73
$158,952
1S74
141,647
1875
150,012
1876
138,256
1S77
159,009
1S78
102,925
1S79
186,123
18S0
203,770
18S1
197,084
1SS2
229,459
1S83
272,475
1884
255.259
1885
239,963
1SS6
272,414
1S87
390,531
1888
234,947
18S9
224,323
1S90
269,997
1S91
254,707
1892
262,023
1893
201,904
1894
203,S27
1895
319,496
1896
270.210
Total, 25.870,310
The following note concerning this local coinage by the Bechtlers is
added by Mr. Geo. B. Hanna of the LT. S. Assay Office at Charlotte.
K C: '
"Gold was coined at Rutherf ordton by three Bechtlers: Christian Bechtler,
A. Beehtler and Christian Bechtler, Jr. A. Bechtler came in between C. Becht-
ler and C. Bechtler, Jr. I have in hand a 5-dollar gold piece stamped ' A.'
1 Christian Bechtler, jeweller by trade, who resided near Kutherfordton, N. C. was urged
by residents in Rutherford and adjoining- counties to coin the gold of that neighborhood, as
transportation to the only mint then existing (Philadelphia, Pa.) was hazardous and difficult.
He commenced coining in 1831, and continued until his death, in 1S43, when his nephew. ('.
Bechtler, Jr., continued the minting until 1857. No regular entries of the quantity of gold
minted were made ; sometimes as much as $4000 to $5000 were coined in a week ; and for a
period of ten years the annual quantity was fairly equal. See Second Annual Bt port Survey
of South Carolina, 1857. O. M. Lieber, p. 135.
2 The years 1838 to 1847 exclude the amounts deposited at the New Orleans Mint, which were
not available for each year. The total amount at New Orleans in those years from the South-
ern States was only $116,086.
42 GOLD MINING IN NORTH CAROLINA.
Beclitler, and it is the most artistic of all the 5-dollar coins. C. Bechtler also
coined 5-dollar gold pieces stamped ' Georgia Gold '; a very few pieces are
stamped ' August 1, 1834,' which date marked a change in the U. S. standard
gold coin. The presumption is that all the Bechtler gold coins prior to this
date were bought up at a premium, and recoined at a profit of nearly 7 per
cent. The denominations coined were $1.00, of quite various patterns, and 2%
and 5-dollar pieces; the dollar pieces ranged from 27 to 30 grains. The coins
were generally stamped with the carat, 20 c. being the lowest observed. The
character of the stamping varied greatly, that of the dollar pieces being very
poor, and these were extensively counterfeited. The alloy was silver and the
coin had a pale brassy look. Some coins were specifically stamped ' North
Carolina ' gold; others merely ' Carolina Gold ' or ' Georgia Gold.' "
In Table ¥o. 3 the totals found in Table No. 2, from the years 1880
to 1896, are distributed among the various States.
Table III. — Statement of Gold and Silver Produced in each of the
Southern States ; Deposited at the United States Mint and Assay
Offices from 1880 to 1896 inclusive.
Md.
Va.
N.C
s. c.
Ga.
Ala.
Tenn.
Total.
1880...
$191
$11,071
$77,405
$10,071
$103,066
$696
$1,270
$203,770
1881 . . .
253
9,147
55,990
23,093
106,548
700
1,353
197,084
1882...
754
13,540
82,473
16,268
114,507
1,690
227
229,459
1883...
310
6,343
100,294
48,428
116,401
147
552
272.475
1884...
2,024
88,861
48,511
115,000
740
123
255,259
1885. . .
. 1,539
2,954
64,826
39,766
128,148
2,611
119
239,963
1886. . .
559
2,873
83,400
36,187
146,027
3,051
317
272,414
18S7...
199
12,613
216,788
52,142
107,531
1,021
231
390,531
1888...
. 2,174
6,514
88,641
37,40S
97,824
1,47S
908
234,947
1889...
558
2,608
81,196
44,923
92,307
2,332
399
224,323
1890...
. 7,852
2,601
75,192
97,646
85,715
626
365
269,997
1891...
. 4,244
4,197
53,993
127,161
63,722
1,222
16S
254,707
1892...
249
4,473
50,336
120,5S2
83,616
2,2S6
4S1
262,023
1893...
203
4,300
36,454
122,964
92,859
4,S95
229
261,904
1894. ..
978
7,643
52,927
98,763
99,095
4,092
329
263,827
1895. ..
500
3,674
54,649
128,904
128,487
2,947
335
319.496
1896. . .
300
3,500
44,946
63,688
151,776
5,700
300
270.210
In the Census Report for 1880, vol. xiii, can be found statistics con-
cerning gold mining in the Southern States tabulated under the follow-
ing headings: Directory of deep mines; Means of handling water in
deep mines; Cost of supplies in deep mines; Directory of ditches; Cost
of ditch plants; Grades and dimensions of ditches; Length of water sea-
son; Placer directory; Tunnels in placer mines; Stamp batteries; Amal-
gamating mills; Arrastras; and Roasting furnaces.
CHAPTER III.
"DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA,
WITH MINING NOTES.1
The North Carolina mines are distributed in three main belts — the
Eastern Carolina, the Carolina, and the South Mountain belts (see
pp. 14, 15-18).
The distribution of gold deposits and geological formations in North
Carolina is indicated in a general way by the accompanying map
(fig. 3, p. 44); but this is shown in greater detail and accuracy on the
larger map which accompanies Bulletin 3 of the Survey reports.
The mining districts of North Carolina have been more extensively
developed than those in any other portion of the South; although
to-day a comparatively small number of the mines are in operation.
Of these, very few can be said to be steady producers, most of the work
being prospecting and preliminary development, with irregular and
spasmodic output. Petty mining, chiefly in the placer ground, is car-
ried on by tributors in various parts of the State.
THE EASTERN CAROLINA BELT.
The principal mines are situated in Warren, Halifax, Franklin and
Nash counties, in an area covering about 300 square miles, and ex-
tending in a southwesterly direction from a point near the Thomas mine,
1^ miles northeast of Ransoms bridge, to and across Tar river.
Among the mines in this belt are the Thomas, Kearney, Taylor,
Mann, Davis, NickArrington, MannArrington, and Portis. Of these
the two latter are, perhaps, of most importance.
The Mann-Arkington mine is situated in the northwest corner of
Nash county, at Argo P. O. The country-rock is chlorite-schist, in part
porphyrinic, striking N. 60° E. and dipping 40° S.E. The ore-body
consists of quartz lenses from minute size up to 12 inches in thickness,
1 For fuller description of some of the mines, the reader is referred to :
Geological Report of the Midland Counties of North Carolina, by Ebenezer Emmons, New
York, 1856.
"The Ores of North Carolina," by W. C. Kerr and George B. Hanna, Nortli Carolina
Geological Survey, 1887.
"The Gold Deposits of North Carolina,1' by H. B. C. Nitze and G. B. Hanna. North Carolina
Geological Survey, 1896. Bull. No. 3.
Unless otherwise stated, the mines are not at present working. The values of the ores arc
not given on our authority ; the same is true of the dimensions of the ore bodies in abandoned
mines and in such as could not be examined.
*—h
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 40
imperfectly interlaminated in the schists and often cutting the same at
low angles. The quartz is usually saccharoidal. The mine has been
opened to a depth of about 108 feet and, so far as is known, was last
worked early in 1894.
The Portis mine is situated near Ransoms bridge in the northeastern
corner of Franklin county. The country-rock is diorite. The ore-
bodies lie in two intersecting belts of reticulated quartz-veins, each
about 9 feet in total width. No work further than prospecting has
been done on these. Small irregular quartz-stringers occur promis-
cuously throughout the country-rock, and the saprolites in general are
stated to be auriferous. The only work of any consequence done here
was surface sluicing and hydraulicking to a depth of 15 to 30 feet.
Sufficient water supply and head are difficult to obtain. It is stated
that 1000 cubic yards, washed in one of the sluice lines, yielded 1018
pennyweights of gold, the loose vein-rock obtained in this mass assaying
about $8 per ton.
THE CAROLINA BELT.
Granville, Person, Alamance, Orange, and Chatham counties are in-
cluded in this belt, being at its northern extremity; but little work of
consequence has been done here. A newly discovered belt of veins has
been recently opened three or four miles east of Oxford (Chatham
mine) ; another in the northern part of Granville county, near Adoniram
and Venable; and still another near the northwest border of the county,
in the copper belt (Hollo way mine).
MINES IN GUILFORD COUNTY.
Among the principal mines are the Fisher Hill, Millis Hill, Hodges
Hill (Hodgins), Fentress (North Carolina), Twin, Gardner Hill, Jacks
Hill, North State (McCullough), Lindsay, Deep River, Beason, Har-
land and Beard, situated from 3 to 10 miles south and southwest from
Greensboro in a general direction towards Jamestown. The country-
rock is granitic.
The Fisher Hill and Millis Hill mines are five to six miles south
of Greensboro. There are two systems of parallel veins, the first run-
ning north and south and the second northeast and southwest. The
aggregate length of the veins on this property is stated to be S or 10
miles. The vein which has been most extensively worked varies from
10 inches to 4 feet in thickness and has been successfully operated at
several points. The mill consists of ten stamps and was running in
1886 and 1887.
The Hodges Hill (Hodgins) mine is two miles east of the Fisher
Hill. The ore is quartz and chalcopyrite, in a flat vein from G inches
to 12 feet thick.
46 GOLD MINING IN NORTH CAROLINA.
The North Carolina (Fentress) mine is 9 to 10 miles south of
Greensboro. The general strike of the vein is X. 25° E.; its dip ranges
from 38° to 60°. The quartz outcrop has been traced for three miles.
The ore is chalcopyrite in quartz and siderite, containing gold. It was
formerly worked for copper. The mine has been opened to a depth of
310 feet, where the ore-shoot was 80 to 90 feet long and 34 inches
wide. The thickness of the vein varies from this to as high as 13 feet.
It was last worked in 1856, and the ores which were shipped ranged
from 14 to 23 per cent, copper.
The Twin mine is six miles southwest of Greensboro. There are
two parallel veins separated by 4 feet of slate. The strike is X. 40' E.
and the dip S.E. The thickness of the vein is about 18 inches, the
ore being auriferous quartz, carrying chalcopyrite.
The Gardner Hill mine is three miles northeast of Jamestown.
There are supposed to be three veins on the property. The main vein
strikes N. 20° E. and clips westward. Its thickness is from a few
inches to 3 feet. The vein-matter is auriferous quartz, carrying chal-
copyrite and some pyrite. The wall-rock is granite, with a slaty gouge
on each side of the veins. The mine has been opened to a depth of 110
feet. It is stated x that the ore ran from $10 to $20 per ton and that
the mine yielded $100,000. It is estimated that the present dumps
contain 25,000 tons of ore. Tentative assays show $3 to $10 per ton.
The North State (McCullough) mine is situated about two miles
west of south from Jamestown. The vein strikes northeast and dips
45° to 80° S.E. The mine was opened to a depth of 325 feet, where
the vein was 4 to 8 feet thick. At the surface it was 2 feet; at the
60-foot level, 4 feet; at the 90-foot level, 10 feet; and at the 130-foot
level, 24 feet in thickness. The ore is quartz carrying gold and sul-
phurets (pyrite and chalcopyrite). The brown ores extend to a depth
of 130 feet and are said to have yielded from $1.50 to $5 per bushel
($15 to $50 per ton).
The last work was done at the depth of 325 feet, where the vein
varied from 4 to 8 feet in width. The equipment consisted of 20
stamps and other machinery, which were last operated in IS 84.
The Jacks Hill is on the northern, and the Lindsay on the southern
extension of the North State vein.
MINES IN RANDOLPH COUNTY.
The mines are in the central and western part of the county. The
country-rock is argillaceous and chloritic schist, probably in large part
sheared eruptives. At the Hoover Hill the rock is a massive porphyrite.
1 Emmons, Geol. Rept. Midland counties of N. C, 1856, pp. 174, etc.
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 47
The Sawyer mine is 5 miles northwest and the Winningham, Slack,
Winslow and Davis Mountain mines are from 2 to 5 miles southwest
of Aslieboro.
During 1895 the application of the cyanide process to the ores of the
Sawyer was experimented with, but finally abandoned
The Hoover Hill mine is situated about 10 miles west of Aslieboro
and 17 miles east of south from High Point. The country-rock
is a basic eruptive which is partially brecciated, the included fragments
being hornstone. In part the rock is slightly schistose. The ore-bodies
consist of belts in this porphyrite, which are pyritic and, filled with
reticulated quartz-veins from less than 1 inch to 12 inches in thickness.
The strike of the belts is I.E. and the dip 30°-60° S.E. The ore-
bodies are intersected by pyroxenic dikes. The mine has been opened
to a depth exceeding 300 feet. The so-called Briols shoot at this depth
furnished ore worth $8 to $10 per ton. The mine was working in June,
1895. It was equipped with a 20-stamp mill in 1882.
The Wilson-Kindley mine is one-half mile southwest from the Hoover
Hill, and the formation is similar.
The Jones (Keystone) mine is 18 miles east-southeast from Lexington.
The country-rock is a very schistose phase of the brecciated porphyrite
described at Hoover Hill. The strike is N". 45° E. and the dip 80°
LAV. The ore-bodies consist of separate belts, 12 to 15 feet wide, of
the schists, impregnated with auriferous pyrites and quartz-stringers.
The entire width of the ore-bearing ground is stated to be 50 to 110
feet. The ore is cheaply mined in open cuts by quarrying. A 40-
stamp mill stands on the property. The ore is stated to mill $2. Assay
value $2 to $7 per ton. Pan concentrates run $22 per ton. Cyanide
experiments have been made in a small temporary plant, and it is stated
that several tests of sulphureted ores gave an extraction of 70 1o 80
per cent. The mine is at present in operation. The Uharie river, 2
miles distant, is the nearest supply from which water could be fur-
nished by pumping, for hydraulicking and sluicing purposes.
The Herring (or Laughlin), Delft and Parish mines are in the
vicinity of the Jones. At the last-mentioned mine free gold is found
in association with actinolite.
The LTharie mine is near the Montgomery county line on the Uharie
river. The ore-bodies are similar to those of the Russell, which i> a
short distance southwest (see p. 52); but unlike that at the Russell, the
work here has been underground, the depth of the shaft being 17<*
feet. A 10-stamp mill was erected in 1887.
MINES IN DAVIDSON COUNTY.
The Lalor (or Allen), Loftin, Eureka and Black mines arc situated
from 2 to 3 miles southeast of Thomasville in the granite. The ores
48 GOLD MINING IN NORTH CAROLINA.
contain gold, silver and copper. At the Lalor mine the depth of the
workings is 140 feet. It was last operated in 1882 by the Campbell
Mining and Reduction Company of Kew York. The mill contains 10
stamps and concentrating machinery. The concentrates contained suf-
ficient copper sulphurets to make a smelting ore.
Two of the more important mines in this county are the Silver Hill
and the Silver Valley.
The Silver Hill (Washington) mine is 10 miles southeast from
Lexington. The country is chloritic schist striking X. 35 ~ E. and dip-
ping 57° !N7W.; it is accompanied by an eruptive porphyrite similar to
that of Hoover Hill. The ore is schist and quartz, carrying a complex
mixture of pyrite, galena, zinc-blende and chalcopyrite. The galena is
rich in silver. A general average of 200 tests of Silver Hill ore shows:1
Per Cent.
Galena 21.9
Pyrite 17.1
Chalcopyrite '. 1.8
Zinc-blende 59.2
Silver and gold 0.025
100.025
The difficulty of successfully treating this complex combination of
sulphurets has repeatedly been felt here. A mechanical separation of
the galena and blende by buddies and similar machinery was perhaps
the most successful of the vast number of concentrating processes tried,
but even here the assays of the tailings and slimes showed great loss.
The ore was for a time treated with some success, without any separa-
tion, for the combined oxides of lead and zinc used in paint manufac-
ture. This class of ore is best adapted to a smelting process in com-
bination with copper ores, such as has been successfully done on the
similar ores of the Silver Valley mine. (See p. 49.)
As far as the 200-foot level certain portions of the vein were filled
with argentiferous galena, which presented no difficulty in treatment.
But below that level the blende gradually increases and finally pre-
dominates over the galena.
Various assays of the Silver Hill ores show:
Carbonate Ores. Pyritie Ores.
(1) '2^ (3) (-P
Gold, per ton SS.27 $2.07 S3. 10 S10.34
Silver, " 20.36 4.65 4.01 2.97
S28.63 S6.72 S7.ll S13.31
Lead, per cent 3.S0 31.94 0.67
Zinc, " . 27.28 2.0S
1 Ores of North Carolina, by W. C. Kerr and G. B. Hanna, 18ST, p. 197.
— • -^
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 49
Galena and Blende Ores.
(5) (6) (7) (8) (9)
Gold, per ton $4.13 $6.20 $4.13 $ $
Silver " 3.23 10.73 11.25 23.86 103.44
. $7.36 $16.93 $15.3S $25.86 $103.44
Lead, per cent 22.94 56.72 12.57 49.00 52.00
Zinc, " 7.14 31.29
The mine has been worked to a depth of GOO feet by numerous and
extensive levels. There are two parallel veins or lodes, known as the
East and West, about 2S feet apart. The strike is E".E. and the dip
45° N.W. At the 60-foot level they come together, making 20 feet
in width; at the 160-foot level the distance between the veins again
widens to 32 feet, and the clip approaches the vertical. At the 200-foot
level the width of the west lode is 10 to 15 feet. This mine was dis-
covered in 1838; it was last worked 12 years ago.
The Silver Valley mine is situated 5 miles northeast of the Silver
Hill. The character of the country and the ore are similar to those
at Silver Hill. The strike of the lode is E~.E. with a dip of 45° N.W.
The hanging is siliceous argillaceous schist, and the foot-wall, a hard
hornstone (devitrifled quartz-porphyry). The outcrop is a barren
milky quartz, 20 feet wide; the sulphurets appear at a depth of 60
feet. The mine has been opened to a depth of 120 feet. The lode is
from 5 to 12 feet in width and consists of alternate bands of slate,
quartz and sulphurets, the latter seams being from 3 to 18 inches thick.
A 20-stamp mill stands on the property.
Some assays of the Silver Valley ores show:
Galena and Blende Ores.
(1) (2) (3)
Gold, per ton $ $4.13 $
Silver, " 17.19 176.49 3S.14
$17.19 $1S0.62 $38.14
Lead, per cent 15.54 55.25 38.80
Zinc, " 31.43 11.24 32.00
Concentrates.
(4) (5) (6) (7)
Gold, per ton $4.13 $4.13 $1.03 $1.65
Silver, " 23.01 44.74 13.0S 14.34
$27.14 $4S.S7 $14.11 $15.99
Lead, per cent 11.18 47.62 9.63 8.13
Zinc, " 27.70 12.6S 27.S4 33.54
The mine was last operated in the latter part of 1893, and the ores
were smelted in a furnace at Thomasville (Xorth Carolina Smelting
Co.). Many attempts have been made at various times to treat these
4
50 GOLD MINING IN NORTH CAROLINA.
complex ores, but unsuccessfully until this last time. A description of
this smelting process, by Dr. Gr. "W. Lehmann, of Baltimore, MxL, is
therefore deemed of interest and is given here in his words:
" The smelting plant situated at Thomasville, X. C, on the line of the
Southern Railroad and within 13 miles of the mines of the Silver Valley Mining
Company, was erected especially for the treatment of the refractory ores from,
this mine.
" The composition of the ore is zinc-blende, galena, iron sulphides, together
with some little copper, silver and gold. An average analysis representing a
large lot delivered at the smelter gave: Zn., 28 per cent.; Pb., 12 per cent.; Cu.,
0.5 per cent.; Ag., 21 ounces per ton; Au., 0.06 ounces per ton. Quite a number
of patent processes have been in operation since the last 10 years at the works
in order to profitably reduce the several metals, but none of these processes
have gone beyond the experimental stage, since none of them proved a commer-
cial success, until about two years ago. At that time Mr. Robert Xininger. of
Newark, X. J., erected a plant which deals with the subject of treating refrac-
tory ores successfully. The plant consists essentially of:
" 1. Down-draft jacket furnace connected with two horizontal jackets, one on
each side of the furnace;
"2. Two condensers connecting with the horizontal jackets;
" 3. Vat house with a series of large vats to receive the flow of liquor from the
condensers and to collect the lead and zinc residues;
" 4. A separate plant for the treatment of the lead residues;
" 5. A separate plant for the treatment of the zinc residues.
" The down-draft furnace, as far as charging and general construction is con-
cerned, is operated in a similar manner as any ordinary jacket-furnace, but the
arrangement of the tuyeres is different and the current of air from the blowers
necessary for the complete combustion of the refractory ore is carried down
through the charge; thence through the horizontal jackets, the condensers,
through two powerful suction blowers along a series of dust chambers, and out
through the stack. A constant spray of water meeting the volatile metallic
fumes of lead and zinc (together with what silver the zinc fumes carry
along) in the two condensers, deposits all the metallic products and carries them
with the liquor into a series of vats where the lead sulphite or sulphate is
deposited on the bottom of the vats, carrying the silver with it. whilst the zinc
remains in solution and is precipitated out of this solution as zinc oxide.
" During the operation the slag is drawn off from openings near the bottom
of the horizontal jackets near the furnace proper, whilst the matte is collected
in the well of the furnace and tapped. This matte carries the copper, gold, and
most of the silver. It is necessary to prepare the charges to the furnace so as
to have not less than 5 per cent, of copper in your charge; otherwise the resulting
matte would be too low in copper and would have to be treated over and over
again. Gold concentrates and even dry ores can be used with advantage as
fluxes and will help to make the process more profitable."
The cause of closing down the furnace was the difficulty of obtaining
sufficient copper ores for fluxing.
During the summer of 1896 some testing work was done on the
placer deposits forming the bottom land along a small creek that
traverses the property. The plant consisted of an iron washer operated
by a hydraulic stream, riffled sluices, amalgamating tables and rockers.
3
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 51
Its capacity is from 40 to 50 tons per day. It was estimated that the
minimum yield of the ground was $2 per ton, and from that up to $4.
Some prospecting was also done on a gold-bearing quartz-vein situ-
ated on the west side of the creek. A 40-foot shaft exposed 7 feet of
vein matter, consisting of quartz and schists carrying pyritic sulphurets.
An assay of an average sample is stated to have given a value of $9.55
per ton. Assays of the more highly pyritic portion (about 4 feet in
width) showed $19.06 per ton, and it is supposed that this material can
be concentrated to $60.
The Welborn (or Smith) mine, which is 2 miles west of the Silver
Hill, carries similar ores.
The Conrad Hill mine is situated 6 miles east of Lexington. The
country-rocks are silicified chloritic and argillaceous schists, striking
K 10°-20° E., and dipping 80° KW. There are two systems of
veins, one parallel to the strike of the schists, and the other cutting the
same at various angles. The vein-matter is quartz and siderite, carrying
chalcopyrite and gold.
A number of these veins have been opened and worked by three
different shafts, the deepest of which, the main or engine shaft, is 400
feet deep.
The thickness of the ore-bodies varies in different portions of the
mines from less than 1 to as much as 20 feet.
The method of preparing and treating the ores at the time the mine
was in operation, was to partially sort underground, and then still fur-
ther hand-cobb and pick on the surface, which product went to the
copper works; the remainder was crushed and jigged and the heads
added to the hand-picked ore above; the tails were counted as waste,
and the middlings were sent to the stamp-mill and amalgamated, where
the tailings from the battery were again partly concentrated by buddies
and blankets, and the concentrates sent to the copper works.
The treatment for the extraction of copper at first was to smelt the
roasted ore in a shaft furnace for matte, from which, after re-smelting,
black copper was obtained and refined. Smelting was superseded by
the Hunt and Douglas wet process. The crushed roasted ore was sub-
jected to a bath of protochloride of iron, for the conversion of the in-
soluble copper minerals to the soluble chloride; after leaching, the
copper was precipitated by metallic iron and then refined. The resi-
dues were milled and amalgamated in order to obtain the gold.
MINES IN MONTGOMERY COUNTY.
The mines of this county are situated in the northern-central and
northwestern parts, along the range of the Uharie mountains.
„^
52 GOLD MINING IN NORTH CAROLINA.
The Carter and Reynolds mines are some 6 miles northeast of Troy.
They have been worked to a depth of 100 and 80 feet, respectively.
Telkiride of gold is stated to occur here.
On the nortwest side of the Uharie mountains is a series of gravel
mines situated in a line between the mountains and the Uharie river.
Among others may be mentioned the Bright, Ophir * (Davis), Spanish
Oak Gap, Dry Hollow, Island Creek, Deep Flat, Pear Tree Hill, Toms
Creek, Bunnell Mountain, Dutchmans Creek, and the Worth. The
available portions of these placers have been exhausted so far as the
present supply of water will answer. The Beaver Dam placer is lo-
cated about 5 miles west of Eldorado.
The Sam Christian mine is situated on the west side of the Uharie
mountains about 9 miles southwest of Troy.
The property contains 1350 acres. It was at one time extensively
worked as a gravel mine by the Sam Christian Company, of London,
England (the last operations were in 1893), the water being obtained
by pumping from the Yadkin river, about 2-J miles distant. The plant
consisted of two Worthington pumps and five 100 horse-power boilers,
with a capacity of delivering to the mine 5,500,000 gallons in 24 hours,
through a 20-inch steel flanged pipe. The elevation of the point of
discharge above the point of supply was 416 feet.
The two principal channels were the Dry Hollow and the Sam
Christian cut. The thickness of the gravel varied between 1 and 3 feet.
The gold was coarse, mostly in nuggets from 5 to 1000 dwts. The
country-rock is the Monroe slate, accompanied by large masses of vol-
canic breccias and cherty felsites (devitrified quartz-porphyry) which
contain many small quartz-veins from -J to 3 inches in thickness, strik-
ing ~N. 70° W. and dipping 60° ]ST.E. Several shafts have been sunk
on some of these narrow veins; but the attempts at deep mining were
failures.
Most of the deep mines are situated in the extreme northwestern cor-
ner of the county, with Eldorado in their center.
The Etjssell mine (Glenbrook Mining Company), is about 3 miles
northeast from Eldorado and but a short distance from the Randolph
county line. The country-rocks are argillaceous slates, both of soft
and silicifled types. Calcite occurs as a coating and in veinlets. In
part at least, if not altogether, these slates are sedimentary; the bedding
and cleavage planes usually coincide, though not always. The strike
and dip is very variable. Diabase dikes occur in the country, but not
in close proximity to the mine. The ore-bodies consist of parallel belts
in the slates, impregnated with iron sulphurets (2 to 4 per cent.") and
free gold, together with quartz-stringers. There are at least six of
1 Tae siprolites have been explored here, and a belt 30 feet wide was found to mill §3 per ton.
N. C. GEOLOGICAL SURVEY.
BULLETIN 10, PLATE II.
• y."
v f
i»r*
iv5»
BIG CUT, RUSSELL MINE, GLEN BROOK, N. C.
' M
\ .1
J
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. Do
these belts within a distance of 2000 feet across the strike. One of the
largest is opened by the Big Cut, an open pit about 300 feet long by 150
feet wide by 60 feet deep (Plate II). On the eastern edge of this cut is
a shaft 150 feet deep, from the bottom of which the ore has been
&toped upward. It is stated that the entire material from the cut aver-
aged about $2 per ton, mill-yield. There were some rich streaks from
1- to 5 feet wide which went much higher. Two stamp-mills are situ-
ated on the property; the new mill contains 40 stamps (Plate III) and
the old one (now in ruins) 30 stamps. It was proposed in 1895 to treat
the Russell ores by the cyanide process; and the American Cyanide
Gold and Silver Recovery Company, of Denver, Col., erected a 30-ton
plant in the following year, and it is stated that experimental tests and
calculations demonstrated the ability to treat the ore for $1 per ton,
on a 100 ton scale, with an extraction of 85 to 90 per cent.
The Appalachian (or Coggins) mine is located near Eldorado. It
is quite similar in character to the Russell, showing large bodies of low-
grade ore. The depth of the last workings was 160 feet. A 40-stamp
mill was erected in 1887, and was moved to the Jones mine, Randolph
county, in 1896.
The Morris Mountain (Davis or Dutton) mine is one mile west of
the Appalachian, and the ore-bodies are similar to those of the Russell
and the Appalachian.
The Riggon Hill mine is located 3 miles east of Eldorado. The
ore-body consists of a quartz-vein, 2-J feet in thickness, lying in and
with the slate country. It has been opened by a shaft 100 feet in
depth. Some very high-grade ores (both in gold and silver) are reported
from here. Prospecting work was being done during the past summer.
The Steel mine is situated about 2 miles southeast of Eldorado. The
country is silicifled schist, striking !N". 25° E. and dipping 70° N.W.
The ore-bodies (9 to 12 feet in thickness) consist of the schists impreg-
nated with sulphurets (galena, blende, chalcopyrite and pyrite^) and
intercalated with quartz-stringers or seams from less than one up to
twelve inches in thickness. The combined thickness of these ore-seams
is rarely less than 15 inches, and is sometimes more than 3 feet. The
ore contains gold and silver in galena, blende, chalcopyrite and pyrite.
Occasional bunches of the ore have been extremely rich, and assays of
the entire mass of the vein-matter have shown values from $20 to $160
per ton. The depth of the mine is 220 feet. It was last operated by
the Genesee Gold Mining Company, the ores being treated in a 40-
stamp mill.
The Saunders mine is an extension of the Steel.
The Moratock mine is situated 8 miles south of Eldorado. The
country-rock is a massive, devitrihed quartz-porphyry and volcanic
54: GOLD MINING IN NORTH CAROLINA.
breccia. It is very sparingly impregnated with sulphurets (pyrite and
some chalcopyrite). Several small quartz-veins (less than 1 inch in
thickness) intersect the mass. The mine consists of a small quarry
opening in the quartz-porphyry. A 10-stamp mill, equipped with a
cyanide plant, stands on the property and was last in operation in July,
1893. The ore was reported to be of too low grade to be profitably
treated.
MINES IN STANLY COUNTY.
The mines are located in the northeastern portion of the county, more
or less on the line of the Southern Railroad branch running from Salis-
bury to Norwood. Among the more important properties are the Haith-
cock, Hearne, Crawford, Lowder, Parker, Crowell and Barringer.
The Haithcock and Hearne mines are about two miles northwest of
Albemarle. The country-rock is clay-slate, striking N.E., and associated
with eruptives. The quartz-veins are stated to be from 2 to 6 feet in
thickness.
The Crawford mine, situated 4 miles northeast from Albemarle, is
a newly discovered placer, and is described in detail on p. 91.
The Lowder mine is situated 4 miles west of Albemarle. It was
opened in 1835, but has not been operated since the war. Previous to
that time it was worked along the outcrop and to a depth of 65 feet.
The quartz-vein is stated to be 3-| feet in thickness, lying approx-
imately with the slates in strike and dip. During the summer of 1895
the mine was unwatered, and some prospecting work was carried on.
The Parker mine (the New London Estates Company, L'td.) is situ-
ated at New London, 9 miles northwest of Albemarle. The property
comprises about 1200 acres. It is now in litigation. The country
slates resemble those of the Monroe type (see p. 16); they are intruded
by successive flows of greenstone porphyry and more basic eruptives,
in part brecciated. The mine shafts have disclosed at least two volcanic
sheets, from 2 to 3 feet thick each, lying horizontally and separated by
sedimentary slates. In places the greenstone is squeezed into nearly
vertical schistose masses. The country is intersected by numberless
quartz-stringers and several larger quartz-veins, which are auriferous.
The principal work at the Parker consisted of hydraulicking (see Plate
IV) in several old gravel channels, which are stated to have yielded
over $200,000. The gold was coarse, usually in nuggets from a few
pennyweights up to 3 pounds. The fineness of the gold is 950 to 970.
The value of the gravel is stated to vary from 44 cents to $2.40 per
cubic yard.
In one of the hydraulic cuts the bed-rock underlying the grit was
decomposed greenstone. Test-pits have shown that this bed-rock is but
Jl
N. C. GEOLOGICAL SURVEY.
BULLETIN 10, PLATE V.
""-■-- -" <q
STAND-PIPE, PARKER MINE.
SLUICES, PARKER MINE, STANLY COUNTY, N. C.
•
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 55
a sheet of greenstone about 3 feet thick, and that it is underlain by
another auriferous gravel deposit, which may be considered virgin
ground, as no attempt has yet been made to work it. There would be
no great difficulty in getting a sluice on the bed-rock beneath this lower
grit, with sufficient fall to carry off the tailings.
The hydraulicking plant is very extensive. It consists of a Worth-
ington compound duplex condensing pump, with two 100 H. P. boilers
(using 7 cords of wood per day, at $1 per cord), situated on the Yadkin
river, 4^ miles from the stand-pipe at the mine, and 340 feet below the
same. The pipe-line on the lower lift is 20 inches in diameter, flange-
riveted, made of ye-inch steel; on the upper lift is a similar steel pipe
12 inches in diameter. Expansion-joints are placed every quarter of a
mile, and the full length of sleeve (8 inches) is necessary to take up
the maximum expansion and contraction of the pipe caused by changes
•of temperature. The capacity of the pump is 1,500,000 gallons in 12
hours; the head furnished from the top of the stand-pipe to the mine-
workings is about 90 feet. (Plate V.)
Besides the gravel channels at the Parker, the saprolites are, in gen-
■eral, auriferous; and a combination sluicing and milling process
(Dahlonega method, see p. 107) was at one time attempted here. The
bank was undercut with powder and the shattered mass moved with the
giants. The material ran about 50 cents a ton in the mill; but only a
small percentage of it was quartz, and an attempt to select the latter
proved unsuccessful. The tailings in the mill were reasonably low;
but the loss of fine gold in the overflow from the mill-tank, in connection
with the exhaustion of the richer available saprolites, led to the aban-
donment of the process.
The mill is a 10-stamp one, built by the Mecklenburg Iron Works of
'Charlotte, E\ C. The weight of the stamps is 650 pounds. In the
Dahlonega practice 4 drops were given 80 times per minute, and round
punched screens were used; there were no inside plates. About 50 per
<?ent. of the gold was saved in the mortars between the dies. The total
cost of milling (including 1 cord of wood at $1), with 1 hand on each
shift at $1, was $4 per 24 hours.
The last work done at the Parker (fall and winter of 1895) was
that of prospecting some of the larger quartz-veins on the property. The
Ross shaft was sunk to a depth of 130 feet and a vein was opened by a
crosscut, showing sulphurets of iron and copper in white quartz, which
gave assay values ranging from $3 to $12 per ton. The same vein had
been exposed in a 130-foot shaft to the west of the Koss, where assays
of the quartz showed values of $3 at the 85-foot and $7 at the 130-
foot level.
The dimensions of the Koss shaft are 5 feet 6 inches bv 11 feet inside
/
56 GOLD MINING IN NORTH CAROLINA.
measurements, with three compartments, the ladder-way being in the
center. The timbers (10 by 12 inches, white oak) are placed in square
sets, with 5 feet centers. The cost of timber is $7 per thousand. The
cost of the shaft (including timbering) was estimated at $10 per foot
for the first hundred feet, $12 for the next hundred, and $15 for the
last fifty feet.
Cost of labor:
Mine foreman (who also does the framing) 12-hr. shift, $1.50
Helper to same " " 1.00
Blacksmith 10-hr. " 1.00
Underground men 12-hr. shift, 75 to 85 cents.
The Crowell mine is situated near the Parker. The ore-body is
a pyritic belt in the country slate, from 4 to 7 feet in thickness, with a
narrow pay-streak. The strike is !N". 10° \V., and the dip 45° X.TT.
The mine has been worked to a depth of 125 feet.
The Little Fritz (formerly the Culp) mine is situated near Glad-
stone. Some prospecting work has lately been in progress here, and an
Elspass frictional roller quartz-mill was erected.
The Barringer mine is situated 4 miles southeast of G old Hill. The
gold is associated with limestone, and very rich ores are stated to have
been mined here.
MINES IN MOORE COUNTY.
The mines are situated in the northern and northwestern parts of the
county. The Jura-trias sandstone, the eastern limit of the Carolina
belt, passes in a southwesterly direction through the central part of the
county, near Carthage.
The Bell mine is situated 8 miles north-northwest from Carthage.
The country-rock is a garnetiferous chlorite-schist, striking N". 55° E.^
and dipping 75° jST.A\r. The ore-body consists of a 4-foot belt in the
schists, containing a small percentage of finely disseminated pyrite and
intercalations of siliceous seams from -J to 4 inches in thickness. The
entire vein-matter is said to run $12 a ton. It is stated that the pay-
streak, 4 to S inches thick, lay against the foot-wall, and that about
2 feet of the material on the foot-wall side was mined and milled, yield-
ing as much as $30 a ton. The mine has been worked to a depth of
110 feet and for a length of 800 feet.
The Grampusville mine is 3 miles southwest of the Bell.
The Burns mine1 is situated 11 miles west-northwest from Carthage,
on Cabin creek. The country is sericitic and chloritic schist, in part
silicified. The strike is K 20° E., and the dip 55° K¥. The ore-
1 See article by H. M. Chance, Eng. and Min. Jour. vol. Lxi, p. 132, 1896.
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 57
bodies consist of certain belts of the country, impregnated with pyrite
and quartz in lenticular stringers. The ore is mined in large open cuts,
20 to 100 feet wide and 50 feet deep. The average ore is stated to
run from $2.50 to $3 per ton in free gold. In 1894 the ores were being
treated in five Crawford mills by the Columbia Mining Company, but
the operations did not apparently prove successful. In 1895 the Cabin
Creek Mining Company built a 10-stamp mill, with bumping-tables for
the concentration of the sulphurets, for the treatment of which it has
been proposed to introduce the cyanide process.
The Clegg, Cagle, Bat Roost, Shields, and Brown mines are situated
from ^ to 3 miles west and north of the Burns. The character of the
country-rock and of the ore-bodies at these is similar to that of the Burns.
MINES IN ANSON COUNTY.
A small patch of crystalline rocks, lying on the south side of the
Jura-trias sandstone, is gold-bearing. Two mines, the Hamilton
(Bailey) and the Jesse Cox, are situated about 2 miles southwest of
Wadesboro. They are not working at present.
MINES IN ROWAN COUNTY.
The mines are located in the southeastern portion of the county in
three general groups:
1. In a line extending from 2 to 9 miles southwest of Salisbury, and
1 to 3 miles east of the Southern Railroad, including the Hartman,.
Yadkin, Negus, Harrison, Hill, Southern Belle, Goodman, Randleman,
and Roseman mines. Not enough is known of these to admit of an
intelligent description.
2. Two to seven miles east and southeast of Salisbury, in the Dunns
Mt. granite area, including the Dunns Mt., New Discovery, Bullion, and
Reimer mines. Of these, the Reimer is fully described on page 117,
and will serve as a type for the others.
3. Nine to ten miles southeast of Salisbury in the metamorphic schists,
including the Gold Hill, Dutch Creek, Gold Knob, Holtshauser, Atlas,.
and Bame mines.
The Gold Hill district was at one time one of the most important
mining centers in North Carolina, if not in the whole South; although
at present no work of consequence is being carried on there. It is situ-
ated about 14 miles southeast of Salisbury, in the southeast corner of
Rowan county, extending into Cabarrus county on the south and Stanly
county on the east. The country-rocks are chloritic and argillaceous
schists, striking N. 25° to 30° E. and dipping 75° to 85° X.AV. A
diabase dike cuts the schists near the village of Gold Hill. The char-
58 GOLD MINING IN NORTH CAROLINA.
aeter of the ore-bodies is that common to these schists elsewhere, con-
sisting of certain belts in the schists filled, with pyritic impregnations
and imperfectly conformable lenticular veins and stringers of quartz.
The principal part of the gold-bearing zone is 1^ miles long from north-
east to southwest and § of a mile wide. There are well-defined veins in
the district, among which the more prominent ones are the Randolph,
Barnhardt, Honeycut, Standard, Trautman and the McMackiiL Some
of these, such as the Trautman and McMackin, are heavy in argentife-
rous galena.1 (See fig. 4, p. 59.)
The first gold was discovered here in 1842, and it is stated that in
the next 14 years the total production of the various mines was $2,000,-
000. In 1853 there was a population of about 2000 in the Gold Hill
camp, at which time the Gold Hill Mining Company operated 5 Chilean
mills and 40 to 50 rockers, working 300 hands. Between 1845 and 1850
the Randolph shaft was put down to a depth of 750 feet. This is the
deepest gold-mine shaft in the South. The Randolph vein was worked
in three principal lenticular ore-shoots, pitching to the northeast, and
varying from 50 to 200 feet in length and from a few inches to 6 feet
in width. It is stated that remarkably rich ores were obtained in those
-days, large quantities yielding from $100 to $500 per ton in the mill.
In 1881 the Randolph shaft was unwatered to the depth of 400 feet.
The method of working the Gold Hill ores in the earlier days is de-
scribed on p. 34.
According to Emmons,2 the amount of gold produced from December,
1853, to June, 1855 (inclusive), as derived from the company's books,
was $136,636.76, and the expenses were $76,429, leaving a net profit
of $60,207.76 for 19 months. During the time which includes the fore-
going record, however, only the ore taken from the poor pockets was
worked.
It is estimated by some that up to 1874 $3,000,000 worth of free gold
in the ore was produced. In 1871, Mr. Amos Howes, the owner at that
time, worked 3 Chilean mills, treating 7 tons of ore per day. The total
daily expenses were $95.51, or $13.64 per ton. Of 8400 tons treated
by Mr. Howes he produced $200,000, or an average yield of $23.81
per ton. It is estimated that only 33 per cent, of the gold was saved by
this method of amalgamation, 67 per cent, going off in the tailings.
The first stamp-mill (20 stamps) was erected in IS SI. The last reg-
ular work was done in 1893 by the New Gold Hill Company, Mr.
Richard Eames, manager, when the ores from the Bamhardt vein,
which are high in copper, were milled in a 10-stamp mill. (See p. 60.)
1 For more detailed description of the structure of the region see Bull. 3; Gold Deposits of
N. C 1896. pp. 83-91.
- Geological Report of the Midland Counties of North Carolina, 1856. E. Emmons, pp. 160 et seq.
M
s-4- K~^"*t,M.tt,6oldHul7eiBs;
60 GOLD MINING IN NORTH CAROLINA.
Mr. Eames carried on some laboratory experiments in 1892 for a cyanide
treatment of the Gold Hill ores, and obtained an extraction of 60 per
cent, on 100 pounds treated. During the summer of 1895 Mr. Bloomer,
of London, experimented with cyanide, but with what result is not
known. Chlorination of the Gold Hill ores has been advised but never
carried out. Xo earnest attempts have been made to treat the sulphurets
on a working scale. Plate YI shows the Eames stamp-mill.
For the past number of years the only work at Gold Hill has been
done by tributors, who cart the decomposed material from the old mine
dumps to the Barnhardt mill, receiving 50 per cent, of the yield. This
material mills about $1.50 per ton. The pulp from the stamps flows
directly over a line of blankets 24 inches wide, which are washed every
20 minutes in a tank; and the concentrates are treated in a series of
hollowed log-rockers, 12 to 14 feet long, provided with quicksilver
riffles (see Plate I, p. 30), the tailings flowing off into the creek.
At the Isenhour mine (Cabarrus county), 1^ miles southwest from
Gold Hill, the ores from a 3-foot vein were ground (during the sum-
mer of 1895) in a Howland pulverizer of 6 tons capacity per 24
hours. The pulp was run over blankets, the washings from which were
treated in rockers, as at the Barnhardt mill, with a yield of about $2
from ores that assayed from $5 to $7 per ton.
The Gold Knob mine is some 5 miles northwest of Gold Hill in the
same general zone of schists. As many as 11 separate parallel ore-leads
have been explored. Of these, the Holtshauser vein was again opened
during the summer of 1895.
The Dutch Creek mines are in the vicinity of Gold Knob. It is
stated that there are 20 veins on the property, some of which are copper-
bearing. The strike of the veins is generally northeast; but there is
a second system striking more northerly and intersecting the first. The
more or less oxidized surface ores have been largely worked out down
to the water-level, below which point the sulphurets remain practically
unchanged.
The Atlas and Bame mines are on the southwest extension of the
Dutch Creek veins.
MINES IN CABARRUS COUNTY.
The metamorphic schists occupy a narrow strip along the eastern edge
of the county, in which are located a series of mines which might be
considered an extension of the Gold Hill zone. Such are the TTiden-
house, Nugget (Biggers), Eva Furr, Allen Eurr, Bocky River, Buffalo,
Reed and Phoenix.
The other mines of the county are situated in the granitic rocks near
Concord and to the southeast and south of Concord. Such are the
Joel Beed, Montgomery, Quaker City, Tucker and Pioneer Mills mines.
J
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 61
The Nugget (Biggers) mine is situated 12 miles southeast of Con-
cord, near Georgeville. The principal operations during the past
three years have been hydraulicking on a gravel channel, similar to
that at the Crawford mine in Stanly county. The gold is coarse,
usually in nuggets. Quartz-veins carrying argentiferous galena have
also been superficially explored.
The Rocky River mine is 10 miles southeast of Concord. The
country is chloritic schist striking !N". 20° E. and dipping 70° N". \V.
Several lenticular quartz-veins, lying more or less with the schists,
have been explored. The quartz contains pyrite, galena, blende and
chalcopyrite. During 1895 Mr. Wayne Darlington, M. E., carried on
some prospecting work on one of these in a shaft 130 feet deep, the
total length of the drifts being about 200 feet. In the 80-foot level
the quartz was 2 J to 3 feet thick; but it pinched out at 130 feet.
Some of the ore was heavy in sulphurets and rich in gold. Crosscuts
have exposed parallel quartz-bodies. However, it appears that no
regular quartz-vein can be depended on. The more or less silicified
schists enclosing the quartz are impregnated with sulphurets and inter-
calated with small quartz-stringers, which, taken together, will make
large bodies of low-grade ores. It is in such that the possible value
of the mine must be looked for.
The Buffalo mine, 1 mile northeast of the Rocky river, presents
similar conditions.
The Reed mine is 1-J miles southeast of the Rocky river. It is the
site of the first discovery of gold in North Carolina. In 1799, a 17-
pound nugget was found, and in 1803 one weighing 28 pounds. The
placer ground was worked vigorously in former years and much nugget-
gold taken out. The estimated yield from 1804 to 1846 is $1,000,-
000. During the year 1895 work at this mine was revived, but it
appears to have been simply of a prospecting character and short-lived.
On April 11, 1896, a nugget weighing 246.83 ounces Troy was found.
It contained 120.87 ounces (10.072 pounds) fine gold, and 5.99 ounces
fine silver. During the latter part of 1896 placer work was being car-
ried on in a small way. The chloritic schists are accompanied by a
large body of greenstone, intersected by numerous quartz-veins vary-
ing in thickness from 4 inches to 3 feet. Some of these are gold-bear-
ing, and were formerly worked by a shaft 120 feet in depth.
The Bhcenix mine is situated 7 miles southeast of Concord. The
country schists are accompanied by a large mass of diabase, in which
the auriferous quartz-veins are confined. The main vein is the Phoenix,
which was extensively and successfully worked under the management
of Captain A. Thies, now of the Haile mine, S. C. Operations ceased
here about 1889. The Phoenix vein strikes X. 70° E. and dips -<>:
62 GOLD MINING IN NORTH CAROLINA.
!N". "W. It varies from 12 inches to 3 feet in thickness. The ore-
shoot, which is 300 feet long and pitches to the northeast, has been
worked out from the 100 to the 425-foot level. The shaft was sunk
to 485 feet on the dip of the vein, but not drifted from. The vein in
the shaft averages 30 inches; but the rich pay-streak, lying on the
hanging wall, is only from 2 to 3 inches thick. It is believed, however,
that if the vein were drifted on at the 425-foot level the 300-foot ore-
shoot just referred to would be reached again. Another ore-shoot, the
Big Sulphur, is situated 300 feet southwest of the above, and has been
worked to the 180-foot level. The ore in the bottom of this shaft (the
pump shaft, 213 feet deep) is stated to be 14 inches thick.
Captain Thies's work was confined to the 300-foot shoot. The ore
was quartz, carrying 3 to 60 per cent, of sulphurets (pyrite, chalcopyrite
and traces of galena). Barite and calcite occur in the gangue. The
cost of mining was $4 per ton. Assays show from 1-| per cent, to 3
per cent, of copper. The mill yield was $10 per ton, besides which the
sulphurets contained $7.50. The concentrates ran $30. Chlorination
was first introduced here in 1880. This was the Mears process, later
developed into the Thies process. A full description of this, with costs-
of working at the Phoenix mine, has been given in a paper by Dr.
William B. Phillips.1
The mill and chlorination plants are now dismantled.
The Barrier, Furness, and Gibb mines adjoin the Phoenix. The Fag-
gart is 3 miles to the northeast, and the Barnhardt is 1-J miles east of
the Faggart.
The Tucker (or California) mine is 1 mile south of the Phoenix. It
was last worked in 1884, by a shaft 175 feet deep, and levels 117 feet
in total length. The quartz-vein was 15 inches wide, and showed
values of $15 per ton. In 1882 the Plattner chlorination process was-
introduced here; but this was later superseded by the Mears process.
The Quaker City mine, which is 3 miles north of the Tucker, has-
not been worked for the past ten years. There are three shafts on the
property, the deepest one being 80 feet. The vein is stated to be from
2 to 5 feet wide.
The Pioneer Mills group of mines is situated 13 miles south of Con-
cord. No work has been done here since the war. The granite is
accompanied by large masses of basic eruptive rocks.
MINES IN UNION COUNTY.
The mines are situated in the metamorphic slates in the western part
of the county. Among the more important may be mentioned the
14kThe Chlorination of Low-grade Auriferous Sulphides," Trans. Am. Inst. Min. Engs.. xviu
pp. 313-322.
-
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 63-
Crowell, Long, Moore, Stewart, Smart, Hemby, Lewis, Phifer, Davis,
Bonnie Belle, and Howie mines.
The Long, Moore, Stewart and Smart are characterized by the pres-
ence of complex sulphurets (pyrite, galena, blende and sometimes chal-
copyrite). At the Moore mine the gold is associated with calcite, which
exists in a pay-streak 4 inches thick on the hanging wall of a 5-foot
quartz-vein.
The Bonnie Belle (Washington) mine is situated 8 miles west of
Monroe. The country is argillaceous schist silicified in varying de-
grees, striking N". 55° E. and dipping steeply RT.W. The ore-deposit
consists of pyrite and quartz impregnations in the schists. The width
of the ore-bearing belt is stated to be 14 feet. It is intersected by a
diabase dike. The mine was in operation during the fall of 1894.
Ores assaying from $4 to $5 per ton were treated in a Chilean mill and
four drag-mills, of 10 tons capacity per 24 hours; the pulp was dis-
charged on amalgamated copper plates and thence to a Gilpin county
humping-table. The concentrates assayed $22, and the tailings 50
cents per ton.
The Howie mine is 1 mile southwest of the Bonnie Belle. The ore-
bearing slates are said to have a total width of 400 feet, within which
there are as many as 8 so-called parallel veins, varying from 18 inches
to 16 feet in thickness. Sulphurets are rare, the gold occurring mainly
as fine films on the cleavage planes of the more or less silicified slates.
It is stated that the ore, when last mined, yielded $13 to $14 in the
mill. The mine has been opened to a depth of 350 feet. Numerous
diabase dikes intersect the ore-bodies, which are said to be richer in the
vicinity of the dikes.
The Monroe slates in the vicinity of Monroe contain some narrow
auriferous quartz-veins, but they are scarcely of economical importance,.
at least so far as present explorations have gone.
MINES IN MECKLENBURG COUNTY.
This has been one of the most important and active gold-mining
counties of the State.
The mines are distributed over the entire county, around Charlotte as
a center. Among the more important are the Davidson Hill (1 mile
west of Charlotte), St. Catherine, Kudisil, Clark (2^ miles west of Char-
lotte), Stephen "Wilson (9 miles west of Charlotte), Smith and Palmer,
Howell, Parks (1 mile northeast of Charlotte), Taylor and Trotter i 3
miles southwest of Charlotte), Brawley (4 miles west of Charlotte),
Arlington (6 miles west of Charlotte), Capps, McGinn, Alexander (8
miles northwest of Charlotte), Dunn (7 miles northwest of Charlotte),
64 GOLD MINING IN NORTH CAROLINA.
Henderson (7 miles northeast of Charlotte), Ferris, Tredinick (7 miles
southeast of Charlotte), Bay (9 miles southeast of Charlotte), Simpson
(10 miles southeast of Charlotte), and Surface Hill (10 miles east of
Charlotte).
The Kudisil mine is 1 mile south of Charlotte. In the upper part
of the mine the country is a silicified, chloritic and argillaceous slate.
At a depth of 200 feet this gives place to a crystalline eruptive rock.
The ore-body consists of two parallel veins close together and sepa-
rated by slate; they are said to vary in thickness from 2 to 6 feet.
The strike is K 30° E. and the dip 45° IW. The mine has been
worked to a maximum depth of 300 feet in three principal shoots, some
of which furnished very rich though highly sulphuretted ores. The
largest of these shoots had a maximum length of 100 feet and a max-
imum thickness of 15 feet; it pitched towards the south, and was fol-
lowed down to below the 300-foot, but never found in the 350-foot level.
~No attempt at concentration and treatment of sulphurets was made.
The Smith and Palmer and the Howell mines are supposed to be on
the southwestern extension of the Rudisil. »
The St. Catherine mine is on the northeastern extension of the
Budisil, and the general features are the same. The deepest workings
are at the 370-foot level. It is reported that no large chimneys of solid
high-grade ore were found below the 250-foot level; but between the
200 and 370 a large shoot, 4 to 60 feet wide, of low-grade ore has been
worked. The ores were treated by battery amalgamation, and the sul-
phurets were concentrated; these were probably shipped north or else-
where for smelting.
The Capps mine is 5-1 miles northwest of Charlotte. There are two
convergent veins, the Capps striking 1ST. 30° W. and dipping 40° W.,
and the Jane striking "N. 40°-60° E., and dipping steeply eastward (see
Fig. 5). The actual intersection of the veins has not been found. The
Capps was worked to a maximum depth of 130 feet in the Bissell shaft.
The filling of the vein is quartz. Its thickness, as explored in the mine
workings, was not less than 20 feet; definite walls were only found at a
few points. The pay-ore was not uniformly distributed in the quartz,
but generally occurred in layers. Four ore-shoots have been explored.
The brown ores extend to a depth of 130 feet. The sulphurets are
pyrite, with some chalcopyrite. The past production of the Capps has
been estimated at over $1,250,000.
In the summer of 1895, Mr. Wilkes, the owner of the Capps. made
at his test plant in Charlotte, a trial run of 50 tons of Capps ore (^sul-
phurets) from the old dumps, and the result of this milling and chlorin-
ation test was a yield of $27 per ton.
Between January and April, 1895, four diamond drill-holes (1-inch
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA.
65
H^0
No. L
Fig. 5. Plan of Capps Mine. Scale, 1 iuch = 200 feet.
/
bb GOLD MINING IN NORTH CAROLINA.
core) were bored on the Capps vein. Fig. 5 shows their position relative
to the mine-workings in plan, as well as a vertical section of the ground
which they explored.
A, Capps vein; B, parallel vein; C, Jane vein; D, diorite; E, 90-foot
level; F, 78-foot level; G, 130-foot level; H, open cut; S, saprolites; m,
drift; n, drift; 1, borehole, 350 feet deep; 2, borehole, 250 feet deep;
3, borehole, 220 feet deep; 4, borehole, 200 feet deep; 5, Penman
shaft, 80 feet deep; 6, Bissell shaft, 125 feet deep; 7, Mauney shaft,
130 feet deep; 8, Baldwin shaft, 120 feet deep; 9, Gooch shaft, 10,
Old shaft; 11, Isabella shaft, 160 feet deep.
The Capps vein was penetrated by each borehole, and showed a
regular thickness of about 20 feet, with walls of fine- and coarse-
grained diorite, at times porphyritic. The dip is quite constant, about
30° S.~W. The vein-matter is quartz, averaging $6 to $7 per ton, as
shown by assays of the drill cores. The drill-holes are certainly very
satisfactory, in so far as they prove the continuity in depth, and regu-
larity in thickness of the Capps vein; and, on a large body of ore, such
as this is, the assays of the drill cores are of value as showing at least
the presence of mineable ores.
The McGinn mine comprises the Jane vein, worked to a depth of
160 feet in the Isabella shaft, and a cross-vein on the northern exten-
sion of the Jane, known as the Copper vein, which has been worked
to the depth of 110 feet as a copper mine.
The Ferris mine is situated 5-J miles northeast of Charlotte. The
character of the vein-matter is milky quartz, carrying free gold and
pyrite. It lies with the schists, striking !N\ 25° E. and dipping 70°
NVW. The quartz is broken up into stringers, the widest solid portion
being 12 inches. The vein, as a whole, is stated to vary from 2J to 5
feet in thickness. In the fall of 1894 the mine was being worked by
two shafts, respectively 56 and 95 feet deep. The ore was treated in
a Chilean mill of 3 tons capacity. It is stated that the concentrates
assay from $45 to $60 per ton.
MINES IN GASTON COUNTY.
Among the mines of this county are the Oliver and Farrar (12 miles
northwest of Charlotte), the former being situated on the Catawba river
near the " big bend," and reported to have been worked by one of the
early German settlers prior to the Revolutionary war; the Rhyne
and Derr (17 miles west of Charlotte), the Duffle and Robinson (16
miles west of Charlotte), the Smith and Sam Beattie (13 miles west of
Charlotte), the McLean (15 miles southwest of Charlotte), the Long-
Creek and the Kings Mountain.
The Long Creek mine is situated in the northern part of the county,
55^
ITOl
■t9 *b&*a:
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 67
about 6 miles northwest of Dallas. The property contains 600 acres.
The country-rock is chloritic schist, striking northeast and dipping 85°
northwest. There are three veins lying with the schists, and consist-
ing of lenticular quartz-bodies. The Asbury vein was 6 to 8 feet thick,
and contained rich ore-shoots carrying sulphurets (pyrite, chalcopyrite,
galena, blende and mispickel). A 10-stamp mill was running here in
1891, and in the following year a Crawford mill was put in, which was,
however, soon abandoned, and the mine has since been practically idle.
The Kings Mountain (Catawba) mine is situated about 1| miles
south of Kings Mountain, a station on the Southern Railroad, in the
southwestern corner of the county. The country-rock is mica-schist,
striking ~H. 50° E. and dipping 70° ~N.~W., intercalated with lenticular
masses of siliceous magnesian limestone. These rocks appear to be of
sedimentary origin. The ore-bodies consist of large lenticular chimneys
or shoots of this limestone, containing auriferous quartz and sulphurets
(pyrite, chalcopyrite and galena up to 3 per cent.). Tellurides also
occur in very small quantity. Five such lenses have been opened in
the mine.
In length these lenses reach about 100 feet and in thickness 20 feet,
being separated by a black graphitic slate carrying coarse pyrite, which
is, however, barren. The mine has been opened to a depth of 320
feet. At the time of our visit 40 tons of ore were being raised per 24
hours by a total force of 20 men. (Cost of mine labor, 75 to 85 cents
per day). The rock is very tough, and 60 per cent, dynamite is used
for blasting. The mill house is equipped with a well-constructed 30-
stamp mill built by the Mecklenburg Iron Works, of Charlotte
(Plate VII), and 5 Frue vanners (6x14 feet). Weight of stamp, 750
pounds. Twenty stamps were dropping 71 times per minute — the height
of drop being 5 inches. The ore was crushed through a 40-mesh brass
wire screen. The mill yield is stated to be $3 per ton, with a loss of
$3 in tailings. Great difficulty was found in saving free gold, and
the quicksilver gave trouble by flouring; this is ascribed to the graphitic
slates which occur with the ore. The concentrates run $35 to $40.
The total cost of mining and milling is $1.75. Two men are employed
in the mill at $1 per day. The cost of wood is $1.35 per cord.
A plant for washing the surface brown ores and saprolites is situated
at the mine, and was in successful operation until lately. It consists
of 2 sets of 12-foot log-washers. The slimes flowed over amal-
gamated copper plates (12 feet by 5 feet), while the material carried
up in the washer was screened through a -J-inch perforated revolving
screen, and then through a 20-mesh brass wire revolving screen,
from whence it passed over copper amalgamating plates. The coarse
material was taken to the stamp-mill. A large proportion of the
I,
68 GOLD MINING IN NORTH CAROLINA.
gold remained in the log-washers; much was caught on the plates below
the fine screens; and the smallest amount, which was all fine gold, was
caught on the slime plates. Trouble was also experienced here by the
flouring of the quicksilver. The bottom land lying directly to the
east of the mine is being worked in shallow pits by tributors, who wash
the grit and soft bed-rock slates in sluice boxes. Panning showed up
very well here, and the ground might pay for hydraulic working on a
large scale.
MINES IN LINCOLN, CATAWBA, DAVIE, ALEXANDER AND YADKIN COUNTIES.
Gold has been found in these counties in isolated localities; but with
few exceptions no mining work of any consequence has been done.
The Dixon mine, in Yadkin county, is a new discovery (1895). The
vein is reported to be several feet in thickness, of high-grade sugary
quartz, containing some copper. Only prospecting work has been
carried on. The developments consist of a 40-foot shaft and 140 feet
of levels on the vein. A hundred tons of ore taken out had a reported
value of $5 per ton.
THE SOUTH MOUNTAIN BELT.
MINES IN CALDWELL COUNTY.
The Miller, Scott Hill, Pax Hill and Baker mines are situated within
a distance of 1-J miles from Johns river, and near the southwestern
boundary line of the county. The mines are located in each in-
stance in close proximity to a wide dike of olivine diabase, which strikes
through the country for many miles in a direction X. 20° \V.
The Miller, Scott Hill, and Pax Hill veins strike X. 50°-60° E. and
dip N.W. ; as far as observed they are from 8 to 12 inches in thickness.
At the Baker mine the strike of the veins is N". 85°-45° \Y., and the
dip is 60°-70° N".E. The thickness is from 2 to 5 feet; the ores con-
tain auriferous and argentiferous galena.
The Bee Mountain mine is about 4 miles northeast of the Baker
mine, and the ores contain zinc-blende, galena and chalcopyrite.
MINES IN BURKE, MCDOWELL AND RUTHERFORD COUNTIES.
By far the greater proportion of gold coming from these counties
has been won by placer mining. With few exceptions, the quartz-
veins are too narrow to justify deep mining. But even in the cases
where the veins are of sufficient width, mining operations have been
very spasmodic and of limited extent. Placer mining on a larger scale
has been carried on during the past years only at a few points. Such
DISTRIBUTION OF GOLD MINES IN NORTH CAROLINA. 69
are the Mills property and Hancock mines in Burke; Cane creek,
Brackettown, Huntsville and Vein Mountain in McDowell, and Golden
Valley in Rutherford county.
The Mills place is fully described elsewhere (p. 95), and will serve
as a type for the other mines of the district. Petty mining is almost
constantly in progress in the above counties, as well as in certain parts
of Cleveland and Polk counties to the south.
Of the quartz-mines, those worthy of mention are the Idler, Elwood
and Vein Mountain.
The Idler (Alta or Monarch) mine is situated about 5 miles north
of Rutherfordton, in Rutherford county. As many as 13 parallel
quartz-veins have been explored here within a distance of \ mile. The
country is gneiss, striking about x>T. 60° W., and dipping 25° to 30°
2\T.E. The veins strike "N. 65° E. The vein-matter is quartz, contain-
ing sulphurets (pyrite and some chalcopyrite). The Alta vein has been
explored to the depth of 105 feet; its thickness is from 10 to 22 inches;
the ore is stated to yield $10 per ton. The mine has been worked in
a desultory way, but is now under water.
The Elwood mine is 1^ miles southwest of the Idler. The character
of the country and of the veins is similar to that of the Idler. The
ore is reported to yield $5 in free gold. The mine was last operated
in 1893.
The Vein Mountain mine is situated in McDowell county on the
Second Broad river. A series of as many as 33 parallel auriferous
quartz-veins crosses Vein mountain in a belt not over J of a mile wide.
The principal . and largest one of these is the Xichols, which has been
prospected in four shafts within a distance of 1200 feet, the deepest one
being 117 feet. The strike of the vein is K 80° E., and the dip 75°
N. \\T. Its thickness is reported to vary from a few inches to 3 feet.
The quartz is mineralized with pyrite, galena, blende and chalcopyrite.
The value of the ores varies from $2.50 to $70 per ton. There is a
10-stamp mill on the property, but it has never been operated on any
regular output.
At Brackettown, 5 miles northeast of Vein mountain, an expensive
shaft has been sunk to a depth of 126 feet, on a parallel series of several
narrow (1 to 6-inch) quartz-veins, with the fallacious hope that these
would come together in depth. It is needless to say that these small
veins will not justify working alone unless the intervening country
(gneiss) is found to contain auriferous sulphurets of sufficient richness
to make large bodies of low-grade ores.
An isolated belt of gold-bearing rocks has been mentioned in Hen-
derson county, N. C. (see p. 20). The only mine situated here is the
Boylston, 12 miles west of Henderson ville. The country-rocks are
/,
/
70
GOLD MINING IN NORTH CAROLINA.
fine-grained, mica- and hornblende-gneisses and schists, in part much
crumpled, striking K 20°-30° E., and dipping 35°-60° K.W. The
quartz-veins coincide, more or less, with the strike of the schist*. The
mine has been opened by a series of shallow shafts and short drifts on
one of these veins, which is from 3 to 4 feet in thickness, with a pay-
streak of 1 to 3 inches on the hanging; it is accompanied, in places, by
a granitic dike. The ores are reported to average about $4 per ton
(assay value); sulphurets occur, chiefly pyrite and some chalcopyrite.
A 10-stamp mill (in bad repair) stands on the property. It has not been
in use since 1889.
MINES IN THE MOUNTAIN COUNTIES.
In the northwestern corner of North Carolina, the copper ores of
some of the Ashe county mines, and some small galena-bearing veins
in Watauga and Wilkes counties, are auriferous.
In the southwestern corner of the State (in Jackson, Swain, and
Cherokee counties) some placer-mining operations have been carried on
from time to time, notably in Georgetown valley, Jackson county, and
about the headwaters and other tributaries of Valley river, in Cherokee
county, but nowhere successfully on a very large scale.
Gold is also stated to occur in Macon county, and this may be a
northern extension of the Georgia belt (see p. 21).
In Horse Cove, Macon county, the Ammons Branch mine has recently
been explored, with the showing of a 10-inch quartz-vein, from which
very rich specimens have been taken.
In the southern part of Clay county the Warne mine is situated at
the northeastern extremity of a small belt of auriferous quartz-veins
which extends southwesterly into Towne county, Ga. (For description
see p. 84).
CHAPTER IV.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPA-
LACHIAN REGION OTFIFR THAN IN NORTH
CAROLINA, WITH MINING NOTES.1
GOLD MINES IN MARYLAND.
The gold mines are situated within the belt of crystalline rocks ex-
tending from Washington to Great Falls, on the Potomac river, in
Montgomery county, and also in the central and northern part of this
county. Geologically, they are included in the Virginia belt (see p. 13).
The greatest development has been in the vicinity of Great Falls,
about 15 miles west of Washington. Among the principal mines in
this region are the Maryland, Montgomery, Harrison (or Sawyer), Irma,
Huddleston, and Allerton-Ream, situated in a belt from 7 to 8 miles
in width.2 The greatest development was during the years 1888-93, in
which time the various properties were worked. Since that time oper-
ations have been carried on in a limited way at the Allerton-Ream, Har-
rison, Miller and Bethesda.
During the winter and early spring of 1895 a considerable amount
of exploratory work was carried on at the Bethesda mine, 7 miles
northwest of Washington, by the Bethesda Mining Company. - Some
$20,000 to $30,000 had formerly been taken from a rich chimney
in a 6-foot quartz-vein at this mine. The old shaft was continued to a
depth of 102 feet, and the ore-shoot found to pinch out. Assays from
the lower end of the chimney ran about $4 per ton. There are no sul-
phurets to speak of in the ore at this depth. The country-rock (mica-
ceous schist) is slightly auriferous in places. It is stated that large
areas of the saprolites will yield 18 cents per cubic yard. Sufficient
water-supply for hydraulicking or sluicing is difficult to obtain.
GOLD MINES IN VIRGINIA.
The principal gold region of this State is comprised in the Virginia
belt (see p. 13). A small, isolated area of placer deposits is situated on
the west side of the Blue Ridge in Montgomery and Floyd counties.
1 Unless otherwise stated, the mines are not at present working-. The values of the ores are
not given on our authority ; the same is true of the dimensions of the ore bodies in abandoned
mines, and in such as could not be examined.
2 The best description of these mines has been given by Mr. S. F. Emmons, in a paper entitled
"Notes on the Gold-Deposits of Montgomery County, Maryland," Trans. Am. Inst. Min.
Enqs., xviii, 1890, pp. 391 to 412.
72 GOLD MINING IN VIRGINIA.
So far as is known, none of the Virginia mines are at present working
on an actively producing scale, although considerable prospecting is in
progress and apparent preparations for mining are being made.
The mines of Fauquier, Stafford, Culpeper, Orange and Spottsyl-
vania counties are grouped around the junction of the Rappahannock
and Rapidan rivers in a belt some 15 miles wide.
MINES IN FAUQUIER COUNTY.
The Franklin, Wycoff and Leopold mines are situated in the southern
part of the county near Morrisville.
MINES IN STAFFORD COUNTY.
The principal localities are in the western part of the county near the
Rappahannock river. The Eagle mine, situated 12 miles northwest of
Fredericksburg, was worked by the Rappahannock Gold Mining Com-
pany in 1894; greatest depth, 250 feet; length of workings, 600 feet.
The Monroe mine adjoins the Eagle on the northwest, and the Lee
mine is situated in the same vicinity.
The Rattlesnake mine adjoins the Eagle on the northwest. It was
worked as a gulch placer; large amounts of nuggets are reported, weigh-
ing from -J to 5 dwts. ; some as high as 125 dwts.
MINES IN CULPEPER COUNTY.
The Culpeper mine is situated 18 miles west of Fredericksburg on
the Rapidan river. Prof. Silliman (in a report made in 1836) stated
the average value of this ore to be $25 per ton, and the mining and
milling expenses at $7 per ton. Other mines in the district are the
Richardville and the Ellis.
The. Powhatan Land and Mining Company operated a mine in this
county in 1894, treating the ore in Crawford mills and a ten-stamp mill
(Fraser and Chalmers' make) in connection with Frue vanners.
mines in spottsylvania county.
The oldest mines worked in this county were those operated by the
United States Mining Company near the Rappahannock river in the
extreme northwest corner of the county. A description of the method
of milling at these mines in 1835 is given on p. 33. At that time a
2 -foot vein was operated by adits and several shafts, the deepest of
which was 80 feet. The value of the ore is given in this early report at
$25 per ton, and the cost of milling at 80 cents per ton. Other old
mines near this property are the Marshall and the Gardiner.
£
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 73
In the central portion of the county there is a group of mines, most
prominent among which is the Whitehall,1 which was, in active operation
as late as 1884. Other properties in this group are the Kiggins, Johns-
ton, Pnllian and Grindstone Hill mines.
Still farther south are the Mitchell and the Goodwin mines. They
are located on Pigeon run, along which considerable placer-work was
done in the earlier days. Both have been worked within the past
twelve years, but no paying vein was developed.
MINES IN ORANGE COUNTY.
The gold mines of this county are situated in the northeast corner
near the Rapidan river. The most prominent one among them is the
Vaucluse, which was discovered and opened in 1832. A description of
the milling practice at this mine in 1847 is given on p. 34. Other
mines in the vicinity are the Orange Grove, Greenwood and Melville.
MINES IN LOUISA COUNTY.
The gold-bearing rocks traverse the central portion of the county in
a southwesterly direction, forming a narrow belt but a few miles in
width. In this belt, near the centre of the county, and from 2 to 6
miles northeast of Mineral City (Tolersville), are the Louisa county
pyrite mines. These large bodies of sulphurets, occurring in lenses with
a maximum thickness of 60 feet, and developed to a depth of over 600
feet, are probably of contemporaneous origin with the gold-veins. They
show the same strike (N. 30° E.), dip (60° S.E.) and pitch of shoots or
ore lenses (45° E".E.) as the quartz-veins in the vicinity. Traces of gold
are found in the pyrite deposits, and small gold-bearing quartz-veins
have been encountered in the mines. We quote from a letter written
by Mr. W. H. Adams, manager of the Arminius Pyrite Mines, Mineral
City, to whose kindness we are much indebted:
" It is true that in the pyrite vein, as now opened, there are traces of gold
and silver, but I do not think the average so high as $1.00 per ton, and have
found that gold carries only in certain lines, and that nearly all the vein matter
is barren. There are, in all of the properties, easily traceable quartz-veins in
the hanging- and foot-slates, which are gold-bearing to the extent of $4.00 to
$15.00 per ton, but these veins are always narrow — about as you saw them
in our No. 3 shaft (3 to 7 inches). They are, however, persistent, and I have
no doubt that chimneys are to be found at points of contact of the veins and
dikes, which chimneys will be found to be the source of much of the gold so
prevalent in the streams of the neighborhood."
The scope of this report will not permit a detailed description of these
interesting pyrite deposits or the methods of mining and concentration
1 See Am. Jour. Sci., i, xxxii, 1837, p. 101.
'"-
74 GOLD MINING IN VIRGINIA.
pursued here.1 It may, however, be of value to give the cost of labor
at these mines, as this would apply equally to auriferous mining. The
daily wages paid are:
Carpenters $1.25 to $1.75
Engineers 1.40
Blacksmiths 1.30 to 1.75
Drill-runners 1.35
Helpers 1.20
General labor (under ground) 1.00
" (above ground) 0.90 to 1.00
The Tinder Flats placer deposits ' are situated at the northern end of
the pyrite bodies on both banks of JSTorth Contrary creek.
This bottom was perhaps the best known and most productive source
of placer-gold in the early days of Virginia gold-mining.
At present the problem is one of reworking shallow placer bot-
toms on a large scale, and at the time of our visit in 1895, Mr. W. H.
Case, of Charlotte, ~N. C, was testing the ground with this object in view.
Water under natural head cannot be obtained here, the surrounding
country being a but slightly indented pene-plain it would probably
have to be pumped from the North Anna river.
One-half mile southwest of the Arminius pyrite mine, on the same
line of strike, is the Walton gold mine. This mine has produced some
very rich ore from a shoot or chimney developed to a depth of 150 feet.
The property has been tied up in litigation for the past twelve years.
Near Mineral City (Tolersville) a vein, known as the Fisher Lode,
striking parallel to the pyrite veins and about 2 miles to the east of
them, has been opened by the Harris, Luce, Slate Hill, Louisa and
Warren Hill mines. Two of these, the Luce and Slate Hill, were in
operation at the time of our visit.
The Luce mine had been developed to a depth of 200 feet, and the
total length of drifting on the vein is over 1000 feet. The thickness
of this vein is from 3 to 8 feet. The mine is equipped with a 20-stamp,
hand-feed mill (Fraser and Chalmers' build).
The Slate Hill mine was first opened in 1850, and for a time was
extensively worked. It is the southwest extension of the Luce, which
formerly constituted a portion of the property. Two veins are devel-
oped to a depth of 150 feet. In a report made in 1853, the average
value of the ore is given at $4 per ton, and the cost of mining and mill-
ing at $1.40 per ton. The present company began operations in March,
1895. A Huntington mill has been erected, and the mine was being
developed in the lower levels at the time of our visit.
1 For a description of the deposits, see " Origin of the Iron Pyrites Deposits in Louisa County.
Virginia," by Frank L. Nason ; Eng. and Min. Jour., Ivii, 1894, pp. 414-16.
2 See Am. Jour. Sci., i, xxxii, 1837, pp. 101, 110.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 75
MINES IN FLUVANNA AND GOOCHLAND COUNTIES.1
The same narrow belts traverse the boundary of Goochland and
Fluvanna counties, crossing the James river at Bremo Bluffs into Buck-
ingham county. ~No work but petty placer-mining and more or less
active prospecting is carried on in these counties at present, although
from 1830 to 1860 this region was the field of extensive operations.
Among the well known properties are the Tellurium, the Bowles, the
Payne, the Page, the Hughes, the Moss, the Fisher, the Busby, the
Tagus, the Gilmore, the Collins, Marks, Fades, Big Bird and the
Belzora.
The Tellurium mine, embracing a property of 644 acres, lies partly
in Fluvanna and partly in Goochland county, 6 miles from Columbia,
and is at present owned by the Columbia Gold Mining Company. It
was discovered in 1834 by George Fisher, and is reported to have yielded
$1,000,000 during its various periods of activity. It was last operated
in 1886. Three principal parallel veins, the " : Sandstone," " Middle "
and " Little," traverse the property in a southwesterly direction for a
distance of about half a mile. None of the workings have extended
below a depth of 60 feet.
The Bowles mine adjoins the Tellurium, and the Payne mine is in
the same vicinity.
Lying partly in Fluvanna and partly in Goochland county, and within
\ mile of the Tellurium and Bowles mines are the Fisher, the Moss and
the Busby mines, all on the same lode.
The Fisher mine was opened in 1860 by James Fisher. The main
developments consist of a 40-foot shaft with 175 feet of levels. The
vein is narrow, from 3 to 15 inches, and the ore is stated to carry from
$25 to $300 per ton.
The Moss mine is one mile northeast of the Fisher. It was discovered
in 1835 by John Moss. It has been worked to a depth of 65 feet, and
the vein, which is 2 feet wide in places, carries reported values of $15 to
$65 per ton. ^
The Busby mine is one-half mile northeast of the Moss. Prof. Silli-
man, in an early report, gives ore values of $160 per ton from here.
The work has been altogether of a superficial nature.
The Page mine is situated \ mile west of Wilmington on Long Island
creek in Fluvanna county. Work was begun on the quartz-veins in
1856, when an 8-stamp mill was erected. Considerable prospecting
work has been carried on lately.
The Hughes mine is 5 miles from Bremo Bluffs in Fluvanna county.
1 We beg to acknowledge our indebtedness to Messrs. Wm. Bugbee and Scott Thurston ot
Palmyra, Va., for information concerning the mines of these counties.
I 6 GOLD MINING IN SOUTH CAROLINA.
It was opened in 1836. The last work was done about 4 years ago, when
a 60 -foot shaft was sunk, but without encouraging results.
The Belzoea mine is 7 miles from Columbia in Goochland county.
It was discovered in 1832, and was worked by surface washing until
1849, and after that the veins were opened. The Marks, Collins,
Eades and Big Bird mines adjoin the Belzora.
MINES IN BUCKINGHAM COUNTY.
This is the most southwesterly county of the Virginia gold belt in
which mines have been actively operated. The occurrence of gold has,
however, been reported still farther to the southwest, in Appomattox,
Prince Edwards, Charlotte, and Halifax counties.
The Booker, mine, near Whitehall Station, was worked prior to 1860
by an English company. The deepest shaft is 110 feet. The ore was
crushed in a Howland mill and yielded $13 per ton.
Another English company operated the London mine, seven miles
north of the Booker, for a number of years. Other mines of equal
importance in their day are the Garnett and Mosely (3 miles west of
Willis mountain), the Buckingham, the Morton, the Morrow, the Dun-
can, the Ford, and the Lightfoot.
MINES IN FLOYD AND MONTGOMERY COUNTIES.
A small placer-mining field was opened here (on the west side of
the Blue Ridge) in 1879, along Brush and Laurel creeks and other
small streams running from Pilot mountain. The area embraces about
80 square miles.
The Walters and Gardner mine in Montgomery county was operated
in 1893.
Gold also occurs it Patrick, Carroll and Grayson counties, but prob-
ably only to a very limited extent, associated with copper ores.
GOLD MINES IN SOUTH CAROLINA.
The present gold output of South Carolina is derived almost entirely
from the Haile mine.
To show the extent and distribution of the gold-mining industry in
South Carolina before the war, the following table comprising the work-
ing mines in 1859 is given: 1
Chesterfield and Lancaster counties 21 working mines.
Spartanburg, Union and York counties 19
Abbeville and Edgefield counties 10 " "
Greenville and Pickens counties S " placers.
Total in State 5S
1South Carolina. Resources, etc., published by the State Board of Agriculture, Charleston,
1883, p- 134.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 'I (
Some of these were probably minor operations, as Lieber1 in his
reports, made a few years earlier, complained of the lack of interest taken
in the South Carolina gold mines.
CAROLINA BELT.
Chesterfield County. — The Brewer mine is the main point of in-
terest in this county. It is fully described on p. 144.
In the same neighborhood are the old Kirkley, Leach and Mclnnis
mines. Some gravel mining has been done near the northern boundary
of this county.
Lancaster County. — The Haile mine is fully described on p. 125.
The Funderburk, 8 miles northeast of the Haile, and of the same char-
acter, was worked as late as 188 7. The Clyburne property is situated
1J miles southwest of the Haile. Some tributing is done here with
rockers, on saprolite and gulch deposits. Adjoining this on the south-
west is the Gay mine, which shows ore-bodies of the Haile type, but is
little developed. The most southerly occurrence of gold in this district
is at the Williams mine, 7 miles southwest of the Haile.
York County. — There is no active work at present in this county.
Among the older mines of this district are the Wilson, Wallace and
Palmetto.
Union County. — About 3 miles south of Glen Springs are the West
and the Thomson mines. Mr. Becker describes the veins as quartz
lenses similar to the Dahlonega type, interlaminated with mica- and
hornblende-schists. The Thomson mine was operated during the sum-
mer of 1895 on a small scale by the Dahlonega method of mining and
milling.
Abbeville and Edgefield Counties. — Little information could be
obtained regarding the mines of this district. The deposits are probably
closely connected with, and of the same nature as those in McDuffie,
Warren and Columbia counties, Ga. The Dorn mine, situated at the
loAver end of the Abbeville district, was opened in 1852. In the first
year of its operation over $300,000 are said to have been taken from a
rich pocket in this mine; a yield of $100 per ton was considered a poor
one. The rich pockets were, however, soon exhausted; and the mine
was abandoned until 1866, when it was reworked for a short time with
some success, as reported.
SOUTH MOUNTAIN BELT.
Spartanburg, Greenville and Pickens Counties. — The gold dis-
trict in these three Piedmont counties is probably a continuation of the
1 For a full discussion of the occurrence of g-old and a description of the older mines in South
Carolina, see Tuomey (M.), Report on the Oeoloqy of South Carolina, 1848; and Lieber (O. M.).
Reports on the Survey of S. C, 1856, 1857, 1858 and 1859.
7 b GOLD MINING IN GEORGIA.
South Mountain 'belt in ^orth Carolina (page 68), and, as in that dis-
trict, the gold produced has been obtained almost entirely from placer-
deposits. The present operations are purely of a desultory character.
Among the more extensive deposits might be mentioned those of "Wolfe
creek and Tiger river, located on the boundary between Spartanburg
and Greenville counties at the foot of Hogback mountain. The gold in
these bottoms is derived from small quartz-veins having the same strike
and dip, and being in other respects similar to those of the South Moun-
tain district in North Carolina. The gravel in the bottom is from a few
inches to 5 feet in thickness. It consists of white, saccharoidal and
glassy, barren quartz. In 1892 the Wolfe creek bottom was worked by
the Wolfe and Tiger Mining Company, with a 2-inch nozzle giant,
supplied with 45 feet head of water by a 4-mile ditch.
Other mining properties in this vicinity are the Hammett, Knott,
Golden Gate, Thompson, Hale and \\Test Springs.
GOLD MINES IN GEORGIA.1
MINES IN RABUN COUNTY.
Some work has been done at the Smith mine near Burton, and at the
Moore Girls' mine, 12 miles northwest of Clayton.
MINES IN HABERSHAM COUNTY.
Practically no work of importance has been done in this county,
excepting perhaps some development work a few miles northeast of
Clarkesville.
MINES IN WHITE COUNTY.
The chief mining district is located in the picturesque Xacoochee
valley and its vicinity. Among the many Indian traditions of this
neighborhood is that of extensive gold mining by the aborigines, but
absolute proof of this is wanting.
The Lumsden mine is situated about 2 miles north of the Nacoochee
valley on Bean creek. Several rich quartz-stringers were being worked
in 1895 by tributors, using a combination of hydraulic and dry mining,
the hard ore being hauled £ mile to a wooden 10-stamp mill, driven by
a 20-foot over-shot water-wheel. Five hands are stated to extract 70
to 80 dwts. per week by this crude method.
The J arret mine adjoins the Lumsden on the south; a 20-stamp-
mill was operated here for some time by Mr. Childs, of Athens, Ga.,
1 For a more complete statement concerning gold mines and mining in Georgia see Bulletin
No. 2 of the Georgia Geological Survey, Atlanta, Ga.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 79
using the Dahlonega method of sluicing and milling (see p. 107). It has
been idle for the past eight or nine years.
The Yonah Land and Mining Company controls some 4800 acres of
mining property situated mainly along the watershed of Dukes creek.
This property is a consolidation of what was formerly known as the
Tonton, the Mercer and the Butt mines. The company has pursued
extensive vein explorations on their land under the direction of Mr. E.
T. Whatley. This prospecting work has disclosed a large number of
auriferous quartz-veins, which have a general strike of N. 20° E. and a
dip of about 85° S.E., while the dip of the country-rock is steeply to
the E\"W. Although of low grade ($3 to $7 per ton) and of small width
(6 inches to 3 feet), some of these veins might, under close management,
be mined and milled at a profit. The producing operations of this com-
pany are confined to placer work with hydraulic elevator in the bottom
land of Dukes creek. The elevator used and the method of work in
the pits is similar to that employed by the Chestatee Company (see
p. 101). A 65-foot head of water is obtained from a 7-mile ditch line.
The gravel bed averages about 3 feet in thickness, covered by 6 inches
of peat and clay, and above this about 6 feet of soil overlay. The gold
consists, to a large extent, of extremely rounded and water worn nuggets,
often aggregated in pockets, from one of which $1500 is reported to
have been taken in one day.
The Loud mine, situated near Pleasant Retreat P. O., and about 11
miles east of Dahlonega, is one of the famous placers of the district,
and has produced a large amount of remarkably well crystallized and
wiry nugget gold. It has been known as one of the most extensive
and richest deposits in the Southern States. For the past few years
the work has been confined to hydraulicking old gravel piles. Water,
under a 75-foot head, is leased from the Hand-Barlow Company of Dah-
lonega and is supplied by a ditch 25 miles in length. Extensive cuts in
the saprolites have been made here.
Other properties of importance in White county are the Longstreet
placer, 2-J miles northwest of Cleveland, the Nacoochee Hills Gold
Mining Company, the Martin Mining Company, the St. George prop-
erty (also known as the Dean Mine), the Plattsburg (or Chattahoochee)
Gold Mining and Milling Company, etc.
Besides these there are quite a number of petty operators, some wash-
ing gravel in sluice boxes, others mining rich, narrow seams in the
saprolite and " beating " the ore in wooden stamp-mills, as, for instance,
at the Thompson mine near the Yonah Land Company's property,
where the mining operations were formerly carried on by a mother and
son, the latter digging the quartz and carrying it on his back to the
mill, while his mother attended to the beating.
IB
1
S
so
GOLD MINING IN GEORGIA.
MINES IN HALL COUNTY.
But little active work has been in progress for a number of years.
The principal properties are the Botosi, 12 miles northeast of Gaines-
ville, the Currahee, 6 miles northeast of Gainesville, the Elrod, the
Merrick, the Mammoth and the Glades. The Currahee mine is
equipped with a 20-stamp mill and a roasting furnace. The ore is
quartz, containing pyrite and galena. A set of rolls and a cyanide plant
are now being erected at this mine.
MINES IN LUMPKIN COUNTY.
The principal mining operations are in the vicinity of Dahlonega,
extending from the Yahoola river, about 1 mile northeast of the town,
in a continuous belt nearly 4 miles in width to the mining village of
Auraria (Kunckelsville), a total length of about 6 miles. A general
description of this belt and the method of mining and milling (which
bears the name of the Dahlonega or Georgia method) pursued here is
given on page 107.
This is by all means the most important mining district in Georgia.
In 1838 a United States mint was established in Dahlonega, which con-
tinued in active operation until 1861, during which time $6,106,569
were coined. The nearest railroad point to Dahlonega is Gainesville
(Southern B. B.), 20 miles to the southeast. A connecting branch be-
tween these two points is looked for in the near future, and will greatly
benefit the mining interests of the district.
The following is a list of the prominent mines and their crushing
equipment: Mary Henry (or Murray) (5 stamps); Hand (20 stamps);
Singleton (10 stamps); Yahoola (20 stamps); Stanley (10 stamps):
Findley (40 stamps); Preacher (10 stamps); Hedwig (40 stamps);
Josephine (20 stamps); Lockhart (20 stamps); Barlow (40 stamps);
Balston (20 stamps); Turkey Hill (10 stamps); Woodward (5 stamps);
Ivy (60 stamps); Calhoun (40 stamps); Garnet (20 stamps); Bigley
(20 stamps); Fish Trap (20 stamps); Bast (10 stamps); Siloam (^10
stamps); Lawrence (10 stamps); Horner (5 stamps); Betz (1 Hunting-
ton mill). In the summer and fall of 1896 240 stamps were being
operated at the Bindley, Hand, Yahoola, Murray, Lockhart, Singleton,
Woodward, Breacher, Turkey Hill, Balston, Barlow and Hedwig mines.
Of late years more attention is being paid to the deep-mining of hard
ore in distinction to the usual method in this district of sluicing the soft
saprolites. Thus, at the Lockhart mine, quartz from underground
stopes is treated in a 20-stamp mill (for description of which see p. 115).
The special operations of the Chestatee Company, and of the dredge
boats on the Chestatee river, are described on pages 101, 106.
DISTEIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 81
Among the mines of this district there are some that are operated
by lessees, and in those cases the usual royalty is 25 per cent, for prop-
erties on which a mill and water-power are furnished, and 10 per cent,
where these are absent.
MINES IN DAWSON COUNTY.
At present no active work of any prominence is prosecuted. Among
the mines formerly extensively operated by the Dahlonega method may
be mentioned the Cincinnati Consolidated, the Etowah, the Kin-Mori
and the McGuire, all situated in the vicinity of Dawsonville, the county
seat.
At the Kin-Mori a ditch 34 miles in length, delivering 600 to 700
inches at a pressure of 286 feet, was completed in 1883, and placer-
mining on an extensive scale was carried on in connection with a Hendy
gravel elevator. A 30-stamp mill was erected during the winter of
1884-85. The mine has been idle since 1888.
MINES IN FORSYTHE COUNTY.
No mines of importance have been developed, the gold output having
been derived almost solely from small placer-diggings. The Dr. Charles
property, which is 6 miles southwest of Dawsonville, and not far from
the Cherokee county line, has been prospected to some extent. The
quartz-veins carry arsenical pyrites from the grass roots down, and very
little ordinary pyrites. There is a 10-stamp mill at this mine.
Other properties that might warrant attention are the Little, Settles,
Collins, Sawnee Mt,, Parks, and Fowler.
MINES IN GWINNETT COUNTY.
The Piedmont mine, 2 miles northeast of Buford, has been worked
in a small way until recently. The vein-quartz carries pyrite, galena,
and free gold.
The Shelby mine is 4 miles west of Buford. It is equipped with a
5-stamp mill. The quartz-vein is 2 feet in width, and is stated to
carry values approximating $6 per ton. The Simmons property adjoins
the Shelby on the east.
MINES IN CHEROKEE COUNTY.
At Creighton, near the eastern boundary of this county, is located the
Creighton (Franklin) mine, which, together with the Haile mine of
South Carolina, and some smaller mines in North Carolina, shows
the brighter side of Southern gold-mining. It is a continuously
and systematically worked, dividend-payina' property (for description
6
82 GOLD MINING IN GEORGIA.
see p. 121). Stimulated by the success of this mine, developments are
being pushed on several other properties in this county, mainly along the
approximate strike of the Franklin vein. The properties extend from
a point about 3 miles north of the Creighton, in a more or less continuous
line to the Sixes, Wilkinson, Cherokee (10 stamps), Georgiana, Cox and
Worley mines in the southwestern portion of the county. Xear the
center of this belt, south of the Creighton, the Chester (formerly
Latham) and the Strickland properties have been prospected.
The same auriferous belt, described above as occurring in Cherokee
county, extends through a portion of Barton, Cobb and Paulding coun-
ties. In the latter county a high-grade quartz-vein has been opened up
in the Yorkville mines.
In Douglas county, lenses of auriferous quartz have been explored
to some extent in former years, but no active mining is carried on at
present.
The Mineral Hill mine in this county has been developed by a
double-compartment shaft 120 feet in depth, sunk on the vein. At the
80-foot level the width of the ore-body is estimated to be 15 feet. The
ore is rich in sulphur ets (pyrite and chalcopyrite), and is stated to have
an average value of $8 per ton.
MINES IN CARROLL COUNTY.
The principal mining district is in the vicinity of Villa Rica, where
prospecting and development work has been quite active during recent
years. The principal properties are the Clopton mine, operated by the
Boston Kennesaw Mining Company; the Mineral Farm mine, 3^ miles
northwest from Villa Rica; the Pine Mountain mine, operated by the
Southern States Exploration and Financial Syndicate, L't'd.
MINES IN HARALSON COUNTY.
Several mines have been opened in the southwestern portion of this
county, lying in the belt which, to the southwest, is more extensively
developed near Arbacoochee, Ala. The most important of these is the
Royal (formerly known as the Camille) mine, 2-J miles southwest of
Tallapoosa.
In past years the soft, semi-crystalline slates were sluiced, the loose
free gold saved in the sluice boxes, the quartz milled, and the gold saved
by amalgamation. In the washed-off portion, hundreds of quartz-
stringers, from the size of a knife blade to 5, 6 and more feet in thick-
ness, can be seen striking almost due east and west.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 83
In 1887 a large amount of money was spent in developing the mine
and in erecting a 20-stamp mill (Fraser and Chalmers), with 8 Frue
vanners. A double-compartment inclined shaft was sunk to a depth of
186 feet. The ore was milled at the rate of 4 tons per stamp head.
But little free gold was saved, the loss in the sulphurets being great,
and after a short run the work was abandoned as unprofitable.
In December, 1895, Capt. A. Thies, of the Haile mine, S. C, made
a thorough examination of this property, which resulted in reworking
the mine and the erection of a chlorination plant.
The outcrop of the main vein, on which the 186-foot shaft is sunk,
is exposed for 600 feet west of the shaft. The width of the ore-body
is stated to be 6 feet. The ore in sight stands practically from the 186-
foot level to the surface, and is developed by east and west drifts.
Later, a three-compartment vertical shaft was located south of the
inclined shaft and sunk to a depth of 118 feet. It cut the ore-body at
105 feet and had not passed through it at 118. The ore is hard, white
quartz, heavily sulphuretted.
In the original exploratory work done by Capt. Thies, 8 tons of ore,
including a large amount of hanging wall slates broken from the east
drift of the inclined shaft, were milled and yielded 55 dwts. free gold
and ^ ton of concentrates. Later, 143 tons of ore from the east drift
of the same shaft were milled, realizing 500 dwts. free gold, and 7 tons
of concentrates, assaying $602 per ton. The percentage of sulphurets
(iron pyrites) in the ore varies from 5 to 7 per cent.
There are over 2 acres of old tailing dumps, 8 feet deep, which
material assays from $7 to $8 per ton.
Towards the end of 1896, the mill was increased to 40 stamps with
10 Frue vanners, and a 5 -foot Huntington mill, with 2 Triumph con-
centrators were added. The milling capacity is 1J tons per stamp per
day, and 12 tons per day in the Huntington mill.
Besides the above equipment, 2 reverberatory roasting furnaces, 50x9
feet hearth, and a chlorination plant with two 2-ton barrels, filters, etc.,
were built.
MINES IN MERIWEATHER COUNTY.
The only mine of importance is the Wilkes, situated in the extreme
northwest corner of the county. It is stated to have produced $50,000
from 1873 to 1878, during which years the vein (composed of quartz
lenses 8 to 10 inches thick) was mined to a depth of 130 feet. The
ore, consisting of quartz, with about 3 feet of the adjoining wall-rock,
mills about $4 per ton.
In the spring of 1895 the mine was opened and operations conducted
on a limited scale by Mr. John Cross.
L
84 GOLD MINING IN GEORGIA.
MINES IN TOWNE COUNTY.
A zone of ore-bearing schists about 3 miles in length extends across
the State line into Clay county, "N. C. (see p. 70).
The Warne mine, in Clay county, E". C, is situated on Brasstown
creek, about 8 miles southwest of Haysville and not more than \ mile
north of the Georgia line.
The developments consist of a 60-foot shaft, at the bottom of which
the quartz-vein is stated to be 2 feet in width. There are no under-
ground workings of consequence. The property is equipped with a 10-
stamp mill driven by a turbine wheel with a 20-foot water-fall.
The Old Field mine, in Towne county, Ga., adjoins the Warne on
the southwest. Considerable exploratory work has been done, and a
number of quartz-veins located. There appears to be a good opportunity
here for hydraulicking the saprolitic material over a considerable area;
with a ditch line 2 miles in length a head of 160 feet can be attained.
The JSTancy Brown mine adjoins the Old Field on the southwest, be-
yond which lies the Hunt mine property, where the main developments
consist of a shaft 45 feet deep, and a tunnel 60 feet long. In the
former, the vein, which is composed of vitreous quartz, is stated to vary
from 18 to 36 inches in width, and various assays have shown values
ranging from $10 to $17. In the tunnel the quartz-vein, which strikes
nearly east and west and stands vertically, has a thickness of from 12 to
15 inches, which has given reported mill-test values of $13. The
country is mica-gneiss and -schist, striking N. 70° W. These rocks are
filled with quartz-stringers or veinlets, and in general the district is not
unlike that of the Dahlonega region in Lumpkin county.
The Jack Brown property adjoins the Hunt on the southwest. The
main prospect is an 8-foot quartz-vein, which has a promising appearance
and is stated to carry values from $9 to $125 per ton. The strike of
the vein is ~N. 75° E., and the dip is nearly vertical.
The Welborn Hill mine is situated about -J mile west of the Jack
Brown on a parallel zone of auriferous schists. It was last worked sev-
eral years ago by two shafts respectively 125 and 70 feet deep, cutting
two parallel quartz-veins respectively 36 and 30 inches wide. The
strike is 1ST. 40° E. and the dip steeply to the northwest. The property
is equipped with a 10-stamp mill of the Hall type.
THE CAROLINA BELT (iN GEORGIA).
In the eastern part of the State an auriferous district, which prob-
ably represents the southwesterly extension of the Carolina belt, is
developed to some extent in McDuffie, Warren, Wilkes, Lincoln, and
Columbia counties.
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 85
The most prominent mine in this district is the Smith mine, operated
by Mrs. J. Belknap Smith. It is situated 14 miles northwest of Thom-
son in McDuffie county.
A 3-foot vein of white quartz, carrying free gold, pyrite, chalcopyrite
and galena, and milling from $8 to $24 by simple amalgamation, has
been developed by two shafts to a depth of 160 feet, and for a distance
of about 300 feet along the strike (nearly north and south). The mill
(10 stamps) is located three miles from the mine on Little river. ±^o
attempt is made to save the sulphurets, and the tailings are stated to
carry as high as $12 per ton.
Other mines in this district are the Columbia, Egypt, Tatham, Wil-
liams, Warren, and Magruder.
GOLD MINES IN ALABAMA.1
MINES IN CLEBURNE COUNTY.
All of the more important mines of the county are located in the
Arbacoochee district, situated 7 miles southeast of Heflin, the nearest
railroad point. In the earlier days extensive placer mining was earned
on about § of a mile southwest of the mining village, Arbacoochee,
principally in the Clear Creek valley. The auriferous deposit at this
point covers nearly 100 acres in Sections 5, 6 and 7, T. 17, R. 11 E.
During the summer of 1895 a pocket of very rich quartz was opened
up in one of the old placer pits on the boundary line between Sections
6 and 7. It is stated that between $1000 and $2000 of coarse gold
was taken from about 400 pounds of ore and the immediately overlying
gravel. This find created considerable local stir, and prospecting was
being pushed along the strike of the quartz-vein as far as the direction
could be determined from the very limited dimensions of the ore lens,
the latter having a maximum width of 8 inches, a dip of about 30 ,
and pinching rapidly along the strike in a distance of about 6 feet.
The ultimate value of this find will depend on the continuation of this
shoot in length and depth, or the discovery of new ore-bodies along the
strike of the veins. Prospecting along this ore-lead was still in progress
during 1896.
The only hydraulic work in the State was carried on for a short time
by the Arbacoochee Hydraulic Company on side-hill deposits, about
-J mile east of Arbacoochee. The limited supply of water and poor
management are given as the reasons for failure.
The Anna Howe, the Anna Howe Extension, the Crutchfield and the
Valdor are adjoining properties in the Arbacoochee district. These
1 For a more complete statement concerning- gold mines and mining in Alabama see Bulletins
3 and 5 of Alabama Geological Survey, referred to on p. 13.
86 GOLD MINING IN ALABAMA.
mines are located on a series of narrow, irregular, lenticular quartz-
veins having quite a flat clip. The Anna Howe was developed to a
depth of about 100 feet when the vein pinched out and the mine was
abandoned. The equipment consists of a Huntington mill and Frue
vanner.
The Chulafinnee district is about 8 miles west of Arbacoochee, in
Sections 14, 15, 16, 22, 23, 24, 25, T. 17, E. 9 E. As at Arbacoochee,
extensive placer mining has been prosecuted here in the past, but has
long since been abandoned. Recent prospecting has disclosed some
rich quartz-stringers on the property of Mr. Burrell Higginbotham. The
old King mine, at which a stamp mill was in operation over 20 years
ago, is in the same vicinity.
The Turkey Heaven District comprises a series of mines situated
along the base of the Turkey Heaven mountains. Among the more
important properties are the Miller, the Crown Point, the Moss-Back.
the Pritchard, the Lucky Joe, the Hicks-Wise, the Lee, the Crumpton,
the Middlebrook, the Sutherland, the Bennifield, the Marion- White, and
the James Moore.
The Crown Point mine is equipped with a 5-stamp mill. The Moss-
Back is one of the early discoveries; it is equipped with a 10-stamp mill.
The Lucky Joe 1 is the most extensively developed mine in the district.
It was opened in 1593, and a stamp-mill (Fraser and Chalmers make)
erected. It is stated that the mill runs saved $2.27 a ton by amalgama-
tion, the cost of mining and milling being $1.35 to $1.45 per ton. The
capacity of the mill, using 30-mesh screens, was 30 tons per day. The
pay-ore lies in chimneys and shoots from 3 to 4 feet thick, dipping
about 30° eastward. The workings consist of about 300 feet of drifting
and cross-cutting. Apparently the development of ore did not prove
satisfactory, as the mine was abandoned during the summer of 1894.
The Moss-Back mine, near the Lucky Joe, was opened in the early
seventies. A 10-stamp mill was erected in 1890.
The Hicks-Wise mine was developed by a vertical shaft 110 feet
deep with levels at 20, 40, and 85 feet. Of 3000 tons of ore milled
it is stated that a yield of $2 per ton was obtained by amalgamation.
The ores are graphitic.
The Lee mine is developed by an inclined shaft sunk to a depth of
40 feet on the dip of the ore-body (45°), on which level a drift of 121
feet in length has been run in ore, which varies from 2 to 5 feet in thick-
ness. The plant in operation in 1894 consisted of 3 arrastras and a
Blake crusher. It is stated that the ore will mill $5 per ton.
The Middlebrook is opened by an inclined shaft 20 feet deep on an
ore-body 5 feet in thickness. Panning tests have shown $5 per ton.
1 For full description of this property ee Engineering and Mining Journal, vol. lvi, 1S93, p. 79.
by W. M. Brewer.
-
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 87
The Sutherland ore-body closely resembles the Middlebrook. It
has been but slightly developed to a depth of about 30 feet. An old-
fashioned wooden stamp mill with iron shoes stands on the property.
The Kemp Mountain district is situated in T. 17, K. 10 E. and T.
17, R. 11 E. The two most important properties are the Eckels and
the Golden Eagle. The Eckels mine was opened in 1893 by an open-
cut 8 feet deep and 50 feet long, exposing ore, thin seams of quartz
in decomposed graphitic schist, the entire distance. A shaft was sunk
from the floor of the open cut to a depth of 65 feet. The dip is vertical
down to 36 feet, when it changes to 60° south. A cross-cut at the bot-
tom of the shaft showed that the ore-body had narrowed down to 18
feet. In 1891- the shaft was deepened to 100 feet and the same condi-
tions found to hold. No sytematic work of treating the ore has been
done.
The Golden Eagle (formerly known as the Price) mine has been
opened by a shaft 75 feet deep on the dip of the ore-body about 50°
southeast. The vein-matter, quartz-stringers in hydromica-schist, is
10 feet thick at the bottom of the shaft and is highly sulphuretted, con-
taining also arsenical pyrites. Some rich ore has been found here.
The Dyne-Creek Company has recently made a number of openings
in the vicinity of Kemp Mountain and south of Arbaeoochee.
MINES IN RANDOLPH COUNTY.
The only mine of prominence is the Pinetucky. It might be classed
as belonging to the Arbaeoochee district, and is located about 2 miles
south of Micaville and 11 miles from Heflin, near the northern boun-
dary of the county.
The occurrence of gold-bearing quartz here was discovered by a
Mr. Knight in the early days of gold digging. Numerous shallow
workings, perhaps the most extensive at any one point in the South,
extend in a continuous line for over a mile along the outcrop of the
vein, and give evidence of the large amount of work done here in time
past, as well as of the continuity of the vein. These old workings have
been carried to a maximum depth of 70 feet, and a large amount of
drifting has been done on the course of the vein, which is nearly north
and south, the dip being about 20° east. The vein is a fissure of hard,
bluish quartz in walls of garnetiferous hornblende-schist. It varies in
thickness from the fraction of an inch to 12 inches. The values are
concentrated in chimneys or shoots, and vary from a trace to $150 a
ton. It is claimed that the ore will carry an average of $10 per ton.
About one-half of the gold is free-milling, the other half being con-
tained in the sulphurets (pyrites). The percentage of pyrite in the
S8 GOLD MINING IN ALABAMA.
ore is less than 1 per cent. Assays of concentrates have shown from
$90 to over $600 per ton.
A few years ago a complete and well-constructed 10-stamp mill of
Western pattern (Fraser and Chalmers) was erected on the property
abont 700 feet east of the outcrop. A vertical shaft was started in the
mill house with the object of cutting the vein in depth and hoisting the
ore direct to the grizzly and crusher, situated at the top of the building.
This shaft was sunk to a depth of 50 feet and then abandoned for lack
of funds. In the spring of 1895 the property was leased to the Fair
Mining and Milling Company of Chicago, which began operations by
sinking three (3) vertical diamond drill-holes. The first of these was
driven to a depth of 205 feet without cutting ore. The cores showed
granite at a depth of 55 feet, which alternated with the garnetiferous
country schists to the bottom of the hole. The second hole, bored
about 150 feet east of the old workings to a depth of 130 feet, also
failed to reach the vein. The country schists were passed through at
60 feet, below which they alternated with granite. The third hole,
only 80 feet east of the old workings, was drilled to a depth of 70 feet.
After passing through the country schists, granite was encountered at a
depth of 47 feet, immediately below which the quartz-vein was found
12 inches in thickness; below that a layer of soft gouge, and below that
garnet-schist and granite. A working shaft was started at this point.
In gold quartz-veins of this size the result obtained by diamond drill
borings might often be misleading, as the gold-bearing vein can at times
be distinguished from other quartz only by its gold contents; about this
the drill-core, and still more the cuttings used as assay samples, can give
no reliable information. However, such explorations may disclose other
facts of interest, as, for instance, in this case the discovery of granite
overlying the vein in depth, which may give a clue to the formation of
the vein and more intelligently direct search for it.
The prospecting work at this mine was done with a small Sullivan
drill (J-ineh core). The drill runner furnished by the Sullivan Diamond
Drill Company, of Chicago, received $90 per month. The cost of under-
ground labor in this district is $1 per day and for top labor 80 cents to
$1; cord wood, 75 cents per cord; freight to HefTin (by wagon), 14 miles,
20 cents per 100 pounds.
Near the center of this county, at Wedowee, some placers have been
operated.
The Goldberg district lies in the extreme western part of the county,
running partially into Clay county near Abner. Attention has been
paid in this direction almost entirely to placer mining along the bottom
of Crooked creek. A very considerable amount of prospecting has also
been done on the vein formations, but no regularly producing mines
I Tn»
DISTRIBUTION OF GOLD MINES IN THE SOUTH APPALACHIAN REGION. 89
have yet been developed. Arsenical pyrite is of common occurrence
in the district.
MINES IN CLAY COUNTY.
The more important mining operations have been carried on in the
Idaho district, which embraces an area of about 3 miles square. The
country-rocks are graphitic mica- and hornblende-schists, often garnet-
iferous. The principal properties are the Idaho, ITobbs, Laurel, Chin-
capina, California, and Horns Peak.
The Idaho (or Franklin) mine is situated in Sec. 3, T. 20, K. 7 E.,
on the northwestern side of Shinbone ridge. The main ore-body con-
sists of a large mass of the country schists interlaminated with quartz-
seams and largely stained with manganese oxide. The schistosity stands
almost vertical. This ore-body, which, has a thickness of 50 feet, is
opened by cuts Avhich extend for over 300 feet along the line of strike
and to a maximum depth of 60 feet.
The second ore-body is about 150 feet northwest of the above. It is
locally called the " Little Sampson vein." But little work has been done
here.
The Idaho ore is stated to carry $2 per ton in free gold. The milling
plant, which, was in operation in the winter of 1896, consists of a 5-stamp
mill (crushing capacity 10 tons in 24 hours), and a 5-foot Huntington
mill (crushing capacity 20 tons in 24 hours), the former crushing
through round punched 2 mm. screens, and the latter through 1 mm.
slotted screens. The pulp from both mills goes over shaking coppers
and thence over stationary coppers, which are barred with riffles. From
here it flows over blanket sluices 8 feet wide at the Huntington and 4
feet wide at the stamp-mill. The cost of mining and milling is stated
to be 50 cents per ton, and the cost of delivering from mine to mill 15
cents per ton.
The following rates of wages are paid: Miners, 75 cents per day (10
hours); foremen, millmen, and engineers, $1 per day; millwright, $1.25
per day. The cost of fuel is $2 per day.
The Laurel mine is supposed to be an extension of the Little Sampson
ore-body, and the character of the ores is very similar.
The Chincapina mine is situated on a ridge to the north of the
Laurel and Idaho mines. The character of the ore-body is similar to
that of the Idaho, though the dip is more inclined, about 30° southeast.
"No work of consequence has been done.
At the California mine a 10-stamp mill was erected and operated sev-
eral years ago.
The Horns Peak mine is situated about 1 mile west of the Idaho.
The ore-body, which resembles the others in this district, has been
90 GOLD MINING IN TENNESSEE.
opened by a cross-cut tunnel, determining its thickness to be about 30
feet. Tests made in a small 5-stamp mill located in the vicinity have
demonstrated a saving of $2 per ton by amalgamation.
MINES IN TALLADEGA COUNTY.
The occurrence of gold in this county is limited to the extreme eastern
portion, in the Blue Ridge mountain range. The Riddle and Story
mines have been worked to some extent.
The ore-body at the Riddle mine is a highly sulphuretted quartz-
vein, having a very flat dip towards the southeast. It has been opened
by an inclined shaft on the dip to a depth of 100 feet. The thickness
of the quartz lenses is about 4 inches, pinching to a mere seam in places.
Assays have shown values varying from $20 to $150 per ton. The
prospect pits extend for over half a mile on the course of the vein.
The Story mine lies in the adjoining section to the Riddle. The ore
was mined some years ago from an incline on the vein to a depth of 60
feet. It is similar to that of the Riddle mine.
The occurrence of gold in Coosa, Chilton, Chambers and Tallapoosa
counties has been fully described by Dr. W. B. Phillips in Bulletin
No. 3, Geological Survey of Alabama.
The latter county was at one time the seat of extensive mining opera-
tions in the Goldville, Hog Mountain,1 Silver Hill, Gregory Hill, Blue
Hill, and Farrow Mountain districts.2
GOLD MINES IN TENNESSEE.
The gold produced in this State has been obtained entirely from petty
placer workings in Monroe, Polk, McMinn, and Blount counties. The
most prolific sources have been the deposits along Coco creek, a trib-
utary of the Hiawassee river in Monroe county. Other gold-bearing
streams in this county are the Citico and Cane creeks, and the head-
waters of the Tellico river. Along Whippoorwill branch, a tributary,
of the Tellico, small gold quartz-veins have been discovered, but they
have never been worked.
In the latter part of 1896 a company known as the Cooper Gold
Mining Company was organized for the purpose of developing the Coco
creek gold fields.3
1 Extensive prospecting- work has recently been done at Hog Mountain with the result of
showing the existence thereof a number of thick veins of low grade ore, averaging perhaps
$4 or $5 a ton.
So also in the vicinity of the old Ulrich mines, and across the river at the Bonner, Terrell,
and Gunn mines, much work has been done within the past twelve months.
2 See Bulls. Nos. 3 and 5, Geoloq. Survey of Alabama.
3Eng. and Min. Jour., vol. lxii, p. 374.
■j^tftt
CHAPTER V
THE MINING AND MILLING PRACTICE AT SOME OF THE
CHARACTERISTIC PLACER AND FREE-MILLING
MINES.
THE CRAWFORD (OR INGRAM) MINE, STANLY COUNTY, N. C.
This mine is situated 4 miles southeast of Albemarle, in the Carolina
belt. It represents a type of working in virgin placer ground, the gold
being coarse, usually in nuggets. The mining tract (180 acres) com-
prises a flat hollow or depression, averaging 250 feet in width, which
is drained by a small branch. The country-rock is the dark greenish
Monroe slate (sedimentary), lying in a flat synclinal trough. The aurif-
erous grit, lying on the slate floor, is composed of angular fragments of
quartz and country-rock bound in a clay matrix; the cement is often
hard and stained a brownish or black color. The quartz is of a milky,
vitreous variety, seldom showing ferruginous stains; some pieces show
parallel walls (vein structure) from a few inches up to 1 foot in thick-
ness. No free gold has been found in this quartz. The thickness of
the grit in the center of the synclinal basin is from 1^ to 2 feet, and
of the over-lay 2 to 4 feet, thinning out towards the edges. The length
of the deposit on the company's property is about a quarter of a mile.
The adjoining property on the north is owned by Mr. F. A. Fesperman,
whose place has been worked by tributors. The gold found at the
Crawford is altogether coarse, from the size of a pin's head to nuggets
of considerable weight. The largest nugget was found on August 22,
1895, and weighed 10 pounds. The so-called De Berry nugget, found
April 8, 1895, weighed 8 pounds 5 ounces. These nuggets are scarcely
at all water-worn, being rough and irregular in shape. The fineness of
the gold varies from 850 to 900.
On the hillside to the west of the placer mine several quartz-veins
have been explored by shallow openings along the outcrop. One of
these is from 2 to 3 feet thick, and dips steeply to the east, cutting the
slates both in strike and dip. The quartz, so far as explored, has been
found generally barren, though in several places gold has been panned
from the crushed rock; but no larger pieces have been found giving any
possible clue as to the origin of the nuggets of the placer deposits.
Gold was first discovered in this bottom in August, 1892, the prop-
E
92
GOLD MINING IN NORTH CAROLINA.
- -
£W
THE MINING PRACTICE CEAWFORD MINE. 93
erty being at that time a portion of the W. S. Ingram farm. For two
years it was worked spasmodically by tributors, and 16 to 17 pounds of
nuggets were obtained. In 1894 the property was bought by the Craw-
ford Mining Company of New York, and was put under the able man-
agement of Mr. Richard Eames, Jr., of Salisbury, !N\ C. A sketch of
the method of working which was being pursued in 1895 is given in
fig. 6.
The bottom having insufficient grade to carry off the tailings with
the limited amount of water at hand, a washing tank and sluice were
put up on the side hill at an elevation of about 30 feet above the creek.
The deposit was mined by a system of parallel trenches 12 feet wide,
worked from the lower end of the deposit upward. Track was laid in
these as they advanced. The upper 6 to 18 inches of the over-lay were
thrown off, the remaining 1-J to 2 feet, together with the true grit
(gravel) and 6 to 12 inches of the bed-rock, were shovelled into cars
holding about half a cubic yard. These were trammed to the foot of
the inclined plane (8), and hoisted to the top of the washing plant by a
small friction-drum engine (3) (see fig. 6). This tank was built of
plank and is about 50 feet long, 18 feet wide and 6 feet high. On one
of the sides there is a door or opening 4 feet wide, reaching to within 4
inches of the bottom to a sill. The grit was dumped into the tank and
a constant stream of water kept flowing over it. The action of this
stream was reinforced by water played on the material from a hose nozzle
under a head of 30 feet. This head was obtained from a stand-pipe (4)
to which water was pumped from a reservoir (1) by means of a Hall
duplex pump (2) with a 4-inch discharge. Excepting at the time of the
clean-up, the tank was kept nearly full of gravel, and under the com-
bined action of the two streams of water, closely imitating natural
agencies, a very good concentration of the coarser nuggets was attained
in the tank. The material, partly assisted with a rake, flowed over a
grizzly (6), the bars of which were set 1-J inches apart. The coarser peb-
bles and boulders were forked off, while the finer gravel and sand were
carried down into a sluice (7) situated below the grizzly. The sluice
was 400 feet long, 12 inches wide and 10 inches deep, and had an in-
clination of 6 inches in 10 feet. It contained only about 20 feet of
riffles, and these were situated about 100 feet below the grizzly. Orig-
inally, the whole sluice was filled with riffles, but these were removed
when it was recognized that they were superfluous for saving gold.
The first hundred feet of the sluice were found to aid in thoroughly
washing and disintegrating the material before it reached the riffles, and
gold was seldom found below the first four or five feet of the rirrles.
The upper riffles consisted of diagonal slots cut in 2-inch plank, which
was laid in the bottom of the sluice. The lower riffles were of the longi-
tudinal variety (see fig. 8).
94
GOLD MIKING IN NORTH CAROLINA.
The upper riffles, as well as the surface of the material in the tank,
were examined every evening for larger nuggets. A complete clean-up
was made at odd intervals, depending upon the richness of the material
worked on, etc. The gravel in the tank was entirely worked down by
means of the hose, the coarser nuggets picked out by hand, and the
heavy sand, together with similar material found in the bottom of the
sluice, after taking up the riffles, was washed in a rocker. Xo quick-
silver was used, there being no fine gold whatever. A loss of gold
would more likely be in the form of larger nuggets, which might be
overlooked in forking out the coarser material, or which, on account
of their round form and size, might roll over the riffles to the tailing
heap. One large nugget, of the shape and size of a hen's egg, was
found on the latter. Clay balls (sluice-robbers) also cause considerable
loss.
Fig. 7. — Rocker used by tributors ; Crawford Mine.
pgggg | V/7Z7/7/7/7/7A
Upper End. Lower End.
Fig. 8. — Riffles in sluice-box; Crawford Mine. Scale, }{ ineh = l foot.
When working to full capacity, 25 men were employed at these
mines — 5 men at the tank and sluice, 1 playing the hose and dumping
cars, 1 raking gravel out of the tank, and 3 helping the material down
the sluice and over the riffles, forking out the coarser pebbles. The
latter force was necessitated by the limited supply of water and the de-
sire to work as large quantities as possible. Their work might perhaps
have been assisted by the use of a much shorter sluice, and a somewhat
steeper inclination of the same, without endangering loss in gold of such
a coarse character. The remainder of the force, excepting foreman and
engineer, were employed in digging gravel, taking up bed-rock, etc.
An average day's output consisted of 80 carloads, about 45 cubic yards
of loose gravel. Two and one-half to three cords of wood were burnt a
day, at 65 cents per cord. Labor was paid at the rate of 60 to 65 cents
per day. These figures, with reasonable additions for superintendence,
supplies, etc., placed the cost of mining gravel by this method at about
50 cents per loose cubic yard. From June until November, when the
water-supply is very limited, the right of mining the gravel was let out
to tributors, who turned in as royalty J of the finer gold, including
-■
THE MINING PRACTICE BURKE COUNTY. 95
pieces up to 1 ounce in weight, and -J of the larger nuggets (above 1
ounce). The tributes worked in pairs, one pitting and taking out the
bed-rock while the other one manipulated the rocker (cradle), shown in
fig. 7. It is made up like a barrel, with half-inch staves, smoothed on
the inside, with solid heads, the latter being a little more than half a
circle. One wheelbarrow-load is put in the rocker at a time. After the
gravel is thoroughly disintegrated by vigorous motion of the rocker,
the pebbles, etc., are thrown out, and finally, by a light movement, the
finer and heavier portions are examined closely by eye. It is practically
a panning process on a larger scale. Fifteen minutes are occupied in
cleaning up one charge.
THE MILLS PROPERTY, BURKE COUNTY, N. C.
This property is situated near Brindletown, about 14 miles southwest
from Morganton. It comprises an area of 2460 acres, including the
eastern portion of Pilot Knob and the western flanks of the South moun-
tains, being drained by the waters of Silver creek. The problem here
presented is the reworking of old gravel deposits by a simple hydraulick-
ing process where the grade is sufficient, or, where this is not the case,
by raising the material to the surface by hydraulic elevators.
Geologically, the locality is in the South mountain belt. The general
strike of the crystalline schists 'is 1ST. 20° W. and the dip 20° 1ST.E. The
rocks are decomposed to a considerable depth, reaching often 50 feet and
at times 100 feet. The strike of the auriferous quartz-veins is ~N. 60°
to 70° E. and the dip 70° to 80° KW. These veins are usually from a
knife edge to several inches in thickness, and are too small to work indi-
vidually. One vein from 12 to 18 inches in thickness has been ex-
plored, but was found to be almost barren. The gravel deposits occupy
the present stream beds and adjoining bottoms, and the ancient channels
now covered with deep over-burden and extending into the hillsides
which flank the mountain. From Pilot Knob and along its lower slopes,
a number of these deep channels radiate in all directions.
The facilities for obtaining water for mining purposes are good,
though beset with difficulties. The numerous streams which have their
rise in the South mountains are small though of good flow throughout
most seasons, and it is practicable to collect their water and lead it to
the larger part of the mining ground in ditch and flume-lines and reser-
voirs with sufficient head for sluicing and hydraulicking purposes.
However, the summer months cannot be depended upon for steady work,
as the water-supply is apt to be cut short by droughts. The chief im-
pediment is in the loss of grade before the mining ground in the lower
country is reached, owing to the deep and numerous indentations of the
mountains which it is necessary to circumvent. It is impossible to
96
GOLD MINING IN NORTH CAROLINA.
• M
THE MINING PRACTICE BURKE COUNTY. 97
water some portions of the sidehills except by pumping into reser-
voirs or by constructing expensive syphon-lines.
Brindle creek on the Mills property was the site of the first discovery
of gold in this part of North Carolina, in 1828. "With few exceptions,
most of the virgin placer ground above alluded to has, by more or less
continuous mining operations since then, been worked as high as water
could be obtained with the present ditch lines. Much of the gravel
has been washed over as many as three times. As no regular records
have ever been kept, it is impossible to speak intelligently of the value
of these gravel deposits. Small channels yielding as high as $20 per
cubic yard have been worked, but in general the gravel will yield
from 4 to 50 cents. At present, the available mining ground may
be divided into two general classes: first, the bottom and ancient channel
gravel deposits; second, the decomposed country-rock in place, contain-
ing belts of small auriferous quartz-veins. Not much attention has
been paid to the latter, excepting by tributors who in a spasmodic way
have worked some deposits on the flanks of Brindle ridge, gouging out
the small rich quartz-veins, and extracting the gold by crushing in hand-
mortars and panning; they pay a royalty of 16f per cent, to the owner.
Captain J. C. Mills at one time successfully worked one of these small
quartz-belts by sluicing to a small stamp-mill (Dahlonega method), but
the mill was destroyed by fire and never rebuilt.
In 1894 an English company was formed with the object of again
reworking the principal gravel deposits and obtaining as a by-product
the monazite, which occurs concentrated with the gold and is derived
from the adjacent country-rocks by disintegration. Over a year was
spent in preparing the mining ground, building and repairing ditches,
flumes, etc. It was proposed to concentrate the work at two points, the
first in the bottom land of Silver creek, using a giant and hydraulic
elevator; the second in the bed of Magazine or Parker branch, using a
giant and continuous sluice-box system.
PLACER DEPOSITS ON SILVER CREEK.
Silver creek forms one of the main drainages of the South mountains.
The placer deposits which it was proposed to rework on the Mills prop-
erty are situated near its headwaters. They are about 1 mile in length
and are located mainly upon the west bank, on which the gravel often ex-
tends out a distance of 500 to 600 yards. The main difficulty encoun-
tered was the want of fall in the bed, a feature common to many South-
ern placers. It amounts in this case to less than 1 foot in 100. To over-
come this obstacle for hydraulicking with continuous sluice, the use of
the hydraulic gravel elevator was decided upon. Fig. 9 gives a
98
GOLD MINING IN NORTH CAROLINA.
rough sketch of the plant and method proposed. Twelve miles of ditch
and flume line (1) carry the water from a reservoir, through the Dan
Sisk gap in the South mountains, to a penstock (4), situated 200 feet
above the level of the creek bed. The ditch is cut about 8 inches deep
by 20 inches wide, at a cost of about 25 cents per rod, and is given a
grade of from \\ to 3 inches in 100 feet. The flumes are, at ordinary
grade, 18 inches wide by 12 inches deep (see fig. 10).
A sill, bent, top and side brace are erected every 6 feet at the jointing
point and middle of each box. The bents are made of rough lagging
seldom more than 6 inches in diameter, the greatest height of trestle
being less than 30 feet. The sill of the flume acts as a cap for the
posts. Wherever a small grade becomes necessary, the width of the
flume is doubled. The cost of erecting these flumes is small, equal to
about the cost of the material in them. Lumber is worth $6 to $7 per
thousand.
Fig. 10. — Flume, Mills Property, N. C. Scale, % inch = l foot. «, lxo-ineh board ;
&, 1-inch holes ; c, lx3-inch board ; d, wedging ; e, 1^-inch plank (sides and bottom) ;
/, 2x4-inch sills and cap for bent.
The water, before reaching the penstock, flows through a sand pit
(2, fig. 9), to catch sand, etc., washed into the ditch line from the side.
It then enters the penstock after passing through a screen (3) for
removing leaves, sticks, etc. The pipe (5) leading from penstock is
10-inch spiral riveted sheet-steel (with No. 16 Birmingham gauge),
coated with coal-tar and connected with flanges. Smaller curves are
made by placing cast-iron bevelled wings between the gaskets of the
flanges, larger ones by suitable elbows. Near the gravel pit the 10-
inch pipe branches out through a Y (6) into two 7-inch pipes, supplied
each with a gate-valve, one leading to the giant pen and the other to
the hydraulic elevator (7). These are both of California type and manu-
facture.1 An illustration of the latter in detail is given in fig. 11. The
principle of this device is too well-known to require a description. It
Joshua Hendey Machine Works, San Francisco, Cal.
\
THE MINING PRACTICE BURKE COUNTY.
Fig. 11.— Hydraulic Gravel Elevator, J. C. Mills' land, Burke Co., X. C
/
100
GOLD MINING IN NORTH CAROLINA.
is intended to keep the elevator stationary as long as possible, as its
installation consumes considerable time. A pit must be sunk in the
bed-rock, and as the elevator must also drain the workings (a drain on
the top of bed-rock to the initial point of working was considered too
expensive), the water would gain too much headway while the elevator
is moved. The work in the main pit will be carried diagonally up the
banks of the stream, so as to gain as much grade as possible. As soon
as there is room, a sluice-box (9) will be placed between the working
bank and the elevator-pit. A cross-section of this is given in fig. 12.
Fig. 12. — Section of Sluice-box, J. C. Mills land, Burke Co., N. C. Scale, >£ inchznl
foot. «, 1%-incb: surfaced pine plank (sides and bottom) ; b, 2x4-incb brace; c, 2x4-inch
sill ; d, lx4-incb riffle ; e, lx8-inch sand-board.
The upper part of this sluice will be filled with 3-inch by 1-inch
Mocks and the remainder with 1-inch by 3-inch cross-riffles, placed 11
inches apart and held down by a sand-board, which is halved down on
them. Both will help to protect the sluice-box against wear. All
pebbles, etc., more than \ inch in diameter will be forked out of the
sluices and left in the pit (11). After being raised by the elevator, the
material will pass through another sluice (8), the tailings from which
will be worked for monazite. It is expected that by far the largest part
of the gold will be saved in the first sluice.
Active work was commenced in July, 1895, and after three months'
washing with the giant and hydraulic elevator the undertaking was
abandoned. So far as the working of the machinery was concerned, the
operations were entirely successful, but the yield in gold and monazite
did not meet the expectations.
The f -acre of ground (chiefly tailing dumps, which had already been
worked over in an irregular and imperfect manner several times) that
was worked to an average depth of 9 feet, yielded $350 in gold, and the
monazite was so full of magnetite, rutile, etc., that its saving was not
warranted.
It is by no means intended by this to condemn the property, for it is
of course unjust to judge its value from this single test; and while it is
undoubtedly true that the resources are insufficient to support a com-
pany organized on so large a capitalization as this English company was,
there is no reason why smaller operations should not be entirely suc-
cessful.
THE MINING PRACTICE. 101
PLACER DEPOSITS ON PARKER BRANCH.
The Magazine or Parker branch is a tributary of South Muddy creek.
Its source is at the foot of Pilot Knob, and from the latter several
gravel channels run towards it, sometimes entirely covered with soil,
so as to make their location unrecognizable at the surface. One of
these, the Magazine channel, has been extensively worked, first by open
hydraulic work, and afterwards at the upper end, where the over-burden
grew too heavy, by a tunnel, subsequently connected with the shaft.
The former had a total length of 600 feet, and the latter a depth of 50
feet. The creek bed has also been worked, mainly with rockers. It
was proposed to work this bottom, besides any side-hill channels that
might be found, by giant, sufficient fall being available to carry off the
tailings in a continuous sluice-box below. Water for this work was
brought a distance of 5 miles to a large reservoir on the divide between
South Muddy and Silver creeks, and from here in 2 miles of ditch and
flume, along the foot of Pilot Knob, to a reservoir situated 100 feet above
the creek bottom. This reservoir was designed to hold the water con-
tained in the ditch after the gate at the large reservoir had been closed
in the evening ; and this was to be the first water to be used in the morn-
ing before that from the large reservoir had time to reach this point.
The placer deposit in the creek bed has a total width of 400 feet. The
old gravel banks, etc., were to be broken down and the material run into
sluices similar to those described above, the tailings being carried down
the branch to South Muddy creek.
These operations were, however, never undertaken, owing to the
liquidation of the company before that point was reached.
THE CHESTATEE COMPANY, LUMPKIN COUNTY, GA.
The work pursued here, and its ultimate object, present special fea-
tures of interest, and might warrant a greater application in the Southern
gold-fields. The plant and property of this company are situated 2-J
miles from Dahlonega, on the Chestatee river, about -J mile above the
entrance of Yahoola creek. The property comprises about 250 acres of
placer ground on the banks of the river, together with about 1 mile of
the stream bed. The main object in view was to turn the river into a
new channel and to work the stream-gravel, as well as that in the adja-
cent bottoms.
At the lower end of the property a dam was thrown across the river
and a substantial and well-constructed power station erected, supplying
the power, by means of two 66 -inch Leffel wheels, for a Blake duplex
12-inch by 24-inch pump and a 50 horse-power dynamo. The Leffel
wheels were originally installed to furnish motor-power to a centrifugal
102 GOLD MINING IN GEORGIA.
sand-pump for raising gravel from the channel excavation, but this was
later on abandoned in favor of a hydraulic gravel elevator. The substi-
tution was made for economic reasons as well as for the fact that the
latter had in its favor greater simplicity, more constant work, and easier
portability, as well as greater facility of installation.
This elevator is the design of Mr. W. R. Crandall, the general man-
ager of the Chestatee Company. It combines cheapness and compact-
ness of construction, and a novel feature is the introduction of air at the
nozzle whenever the inlet of the suction-pipe is entirely submerged. Its
mechanism and operation have been admirably described and illustrated
in a paper by Mr. Crandall, presented at the Pittsburgh meeting of the
American Institute of Mining Engineers in February, 1896. \Ye be-
lieve that this form of elevator may have quite an extended and useful
application in many parts of the Southern field, and in order to intelli-
gently bring it before those of our readers to whom the Transactions of
the American Institute of Mining Engineers may be inaccessible, we
cannot do better than to repeat the descriptive portions of Mr. Crandall's
paper,1 changing the numbers of the figures to suit this report:
H^"Fig. 13 shows the elevator in detail; Fig. 14, the manner in which it is set; Fig. 15
the details of the flume, etc. In all the figures the parts are lettered respectively as fol-
lows :
A. Cast-iron elbow at the base of the elevator.
B. Wings or vanes, to straighten the water before it enters the nozzle.
C. Nozzle.
D. Air-cap.
E. Air-inlet pipe, to furnish air when the bottom of the discharge-pipe is submerged.
F. Studs to support the discharge-pipe and to keep it and the nozzle in line.
G. Cast-iron flanged throat.
H. Discharge-pipe.
I. Discharge-box.
K. Hood for discharge-box.
L. Adjustable wood-packing around discharge-pipe.
M. Discharge-flume.
N. Adjustable flume-supports.
This elevator, as used at the Chestatee mine, near Dahlonega, Ga., where it
has been gradually developed and perfected under the needs of practice, consists
essentially of an elbow, A, longer at one side than the other, and coupling by
means of a flange to a 5-inch pipe. At the other extremity are a flange, into
which the nozzle screws, and three studs, F, which support the throat into
which the gravel and water enter to be elevated. The throat slips inside the
6-in. lap-welded pipe, H, for discharging into the flume on the bank, from
which it may be conveyed wherever desired.
The whole apparatus, except the discharge-pipe, may be readily carried by
two men. If it be necessary to move the elevator often, to keep up with the
drainage, the portable character of the outfit is a great advantage.
At the Chestatee mine the practice is about as follows: The water-supply is
conducted to the mine through a 9- inch pipe. At a suitable point the water is
divided, and a 5-inch pipe conveys that used by the lift, while a 7-inch pipe
conducts to the giant. Valves are provided at the Tee, so that one or both
1 Trans. Am. Inst. Engs., xxvi, 1897, pp. 62-68.
THE MINING PRACTICE.
103
HYDRAULIC LIFT
DESIGNED BY
"W. R. Crandall, July, 1895.
{Patent, applied for)
Fig. 13.— Plan of Hydraulic Lift.
i
104: GOLD MINING IN GEORGIA.
may be shut off as necessity requires. The lift is set into the slate to such
depth as may be desired, and connection is made with the water-supply pipe.
The discharge-pipe is then slipped over the throat and the discharge-flume is
put in place, the discharge-pipe being set at such an angle of inclination as
may be necessary to give proper grade to the tailings-flume and allow the pipe
to extend a few inches through the bottom of the hooded box.
The air-pipe, E, is then screwed into place, and the lift is ready for opera-
tion. We govern the depth to which we set the lift into the bed-rock slate by
the hardness or softness of the latter. If it be hard, frequent moving is cheaper
than cutting slate-drains. If soft, we go as deep as the slate will stand without
timbering. This we find to be about 7 feet.
A main drain is then started in the* general direction of our work, from
which laterals are afterwards cut as required; and, at some suitable place
near the lift-pit, a box about 6 feet long by 32 inches wide is set into the
drain at grade, and in this is placed a cast-iron " grizzly " having round holes
2% inches in diameter. This catches any rocks which may escape the forkers,
and insures that nothing will get to the lift which will not readily pass through
the throat, which has, when new, an opening of three inches.
We use straight-bar riffles in the discharge-flume to catch any gold that
may pass through the lift. This we find in practice to be about 5 per cent, of
the total amount recovered, a result largely due to the fact that, when work
is started at a new pit, the ground-sluices are not long enough to settle the
gold thoroughly.
Whenever the drainage afforded by a pit is exhausted the pipe-line is
extended, a new pit is sunk near the gravel-breast, and the work is continued
as before.
As the work follows the general course of the river, the tailings are dis-
charged into the river at the nearest point, the portable tailing-flume being
extended far enough to insure the safety of the immediate bank. The tailings
finally flow through a ditch into the river.
We usually use about 200 feet of 5-inch pipe in the lift water-supply before
extending the 9-inch pipe-line; and we often move up 100 feet, dig the pit, re-set
the lift and get ready for work again in one 12-hour shift with 5 men.
As to the work which the lift will accomplish, I may say that we are using a
lift with l^-inch nozzle, discharging through a 3-inch throat into a 6-inch pipe,
and lifting an average of 18 feet vertically, with water at about 60 pounds
pressure per square inch.
As we are quite near the river, and have the drainage of a side-hill, the
surface-water is considerable, probably fifty gallons per minute. We use a
l^-inch nozzle on the giant, and the lift readily handles all this and all the
dirt and gravel we are able to wash to it. The latter we estimate, from meas-
urements taken at different times, to be about y2 cubic yard per minute of
' topping.' The quantity of gravel is hard to determine, owing to varying
conditions; but it is safe to say that it is all that the amount of water em-
ployed will wash."
Water is supplied to both the elevator and the giant by direct pressure
(about 60 pounds to the square inch) from the Blake pump. This
direct appliance of pressure, without intermediate stand-pipe or reser-
voir, has proved very successful, the only precaution necessary being to
shut off the pump before closing the feed of the giant or elevator. It
THE MINING PRACTICE.
105
PLAN OF SETTING
HYDRAULIC LIFT
as practiced at the Chestatee Mine
Lumpkin Co., Ga.
Scale 1 in. = 6 feet. W. R. Crandall, Snpt.
Fig. 14.— Plan of setting Hydraulic Lift.
1 ELEVATION
I END VIEW
( )
I GROUND PLAN
M END VIEW
S
a
L GROUND PLAN
L ELEVATION
K ELEVATION
N SIDE VIEW
END VIEW
K GROUND FLAN
Fi°\ 15. — Portable Tailings-Flume
DETAILS OF
PORTABLE TAILINGS-FLUME
as used at Chestatc i
Lumpkin Co-,Ga.
Scale 1 iu. = o feet. W. R. CfU tall, S
106 GOLD MINING IN GEORGIA.
lias also this advantage, that when occasion demands it, smaller nozzles
can be used and the pressure thus increased.
The channel is cut 30 to 35 feet wide, down to bed-rock in depth,
and has a total length of about half a mile. It runs almost parallel to
the river, and from 50 to 200 yards from the north bank of the same.
When completed, the waters of the river will be turned into it by means
of a wing-dam.
The gravel above the bed-rock in this channel is auriferous and has
paid the expenses of the preliminary excavations. It averages 1 foot in
thickness, with 6 to 10 feet of over-lay. The latter was worked off during
the night shift (using electric light illumination), and the gravel thus
exposed, as well as about 2 inches of bed-rock, taken up during the
succeeding day.
CHESTATEE RIVER DREDGE-BOATS, LUMPKIN COUNTY, GA.
Dredge-boats of various descriptions have been at work on the Ches-
tatee river for a number of years. The work has been spasmodic, and
failures are more often recorded than successes. The river, where oper-
ated on, is about 100 feet in width and of variable depth. Xumerous
shoals make dredging difficult.
A steam vacuum dredge * was operated for a time on this river; it did
good work, especially in cleaning up the bed-rock. The main difficulty,
and the reason for abandonment, was the banking up of the tailings
around the boat, finally hemming it in.
The Hoy Stone method,2 using the principle of the hydraulic eleva-
tor, was attempted as early as 1883, but proved unsuccessful. In the
summer of 1895 there were two dredge-boats on the river, one above
and the other below New Bridge. The former of these, operated by
Mr. Frye, is on the principle of a continuous bucket elevator. So far
it has not been operated successfully, the buckets and continuous link-
chain proving entirely too light for the work. The other boat was op-
erated at a small profit by Mr. Jacquish. It was erected seven years
ago by the Bucyrus Steam Shovel Company at an initial cost of about
$15,000. After being worked for two years it lay idle until the summer
of 1895.
The machinery is installed on a scow, 26 by 70 feet, drawing 3-J feet
of water. It consists of a Bucyrus shovel (scoop) of 1J tons capacity,
derrick and hoisting-drums for operating the same, a small horizontal
engine and a centrifugal-pump for supplying fresh water to wash the
gravel, and a 60 horse-power locomotive boiler. A barge, 100 by 20
feet, lying alongside of the dredge-boat, carries the sluices. There are
1 See Gold, by A. G. Locke, 1882, p. 890.
2 See R. W. Raymond, in Trans. Am. Inst. Min. Eng., vol. viii, p. 254.
THE MINING AND MILLING PRACTICE. 107
two lines of sluice-boxes, each 3 feet wide and 18 inches high, running
the full length of the barge, and filled with longitudinal riffles, made
up in five-foot racks, composed of 1 by 3-inch slats set 1 inch apart. The
gravel is discharged from the shovel on an iron-shod platform at the
head of these boxes, where the boulders and larger pebbles are removed.
The gold is caught almost entirely in the upper two racks; the tailings
run off into the river in the back of the boat. "When in favorable
ground, the dredge will scoop and deliver an average of 1 bucket every
2 minutes. "When examined there were 3 men on the dredge-boat, engi-
neer, fireman and craneman, and 6 men at the sluice-boxes. Work is car-
ried forward up stream, the scow being moved against the current by an-
choring the scoop and pulling the scow towards it by means of the crane
engine. The main wear and tear are on the lip of the scoop, and on the
chains. A steel lip 12 inches in length wears out in about six months.
The river ground is leased on a royalty of from 5 to 10 per cent, by the
property owners. It is said that gravel as low as 5 cents per cubic yard
can be worked at a profit.
In the spring of 1896 a boat, equipped with a Marion Steam Shovel
Company's dredging outfit, was in operation under the management of
Messrs. Benham and Helmer. A pontoon alongside of the dredge car-
ried a line of sluice-boxes. The material from the dredge was dumped
on a grizzly at the head of the sluice line and washed down by a stream
of water from a ~No. 8 Held and Cisco centrifugal pump having a
capacity of 4500 gallons per minute. The sluice-boxes were 70 feet
in length, 64 inches wide and 12 inches deep, and provided with riffles.
There was a device for carrying back the tailings and depositing them
in the excavation behind the machine. The efficiency of the dredge was
stated to be 800 to 1200 cubic yards per 10 hours. The expenses were
estimated at about $18 per day, and the gross returns at $40 to $120
per day.
THE DAHLONEGA METHOD, WITH SPECIAL DESCRIPTION OF
THE HEDWIG MINE.
The Dahlonega method of mining and milling is one which is par-
ticularly adapted to the large bodies of low-grade auriferous saprolitic
schists, such as exist in the Dahlonega district of Georgia. It consists
in cutting down the soft, decomposed ore-bodies by means of a hydraulic
giant, the water from which carries the material through a line of sluices
to the mill situated some distance below the workings, usually on the
banks of a stream from which it derives its water-power. In the mill
the coarser and heavier portions are retained by means of a screen, and
are fed to the battery by hand, the mud and fine silt being carried
through into the river. Generally, a third of the gold saved is caught
108 GOLD MINING IN GEORGIA.
in the riffles of the mine-sluices, the remainder being obtained in the
mill.
HISTORICAL NOTES.
The Dahlonega method first originated in 1868 by sluicing the ma-
terial from the mines to platforms near the mill, from where it was
hauled to the mill in carts. This was improved by placing bins, with
perforated bottoms, in the stamp-mills, from 4 to 5 feet above and back
of the mortars; underneath this bin was a settling-box, in which the
sandy material settled and the slimes overflowed. At the Child's mill,
near Nacoochee, a plant was erected, consisting of a series of washing
and sizing plate-screens, in which three sizes, coarse, medium and sand,
were made and milled separately. It is stated that all the millable ore
was saved in this way, in a clean shape, free from mud.
The present practice is to flush the material on to the mill floor back
of the batteries, this space in the mill-house being practically arranged
as a large bin with a slat screen (distance between slats about -J inch)
at one end. Frequently a Y-shaped storage-tank is situated outside of
the mill, where the material is collected and flushed into the mill as
occasion requires.
THE WATER-SUPPLY.
The system of reservoirs, ditches, etc., in this district is by far the
most extensive and best equipped in the Southern gold-belt. The prin-
cipal water-line is known as the Hand and Barlow ditch, having a total
length of 34 miles, the main canal being 20 miles long, 6 feet wide and
3 feet deep, and furnishing 800 miners' inches. The grade averages 5
feet to the mile, being 4^ feet on straight lengths, with slightly steeper
grades on bends. The cost of digging this canal was about $1 per rod;
the total cost, including trestling, etc. (excluding syphon-line), was
$1000 per mile. The canal crosses the Yahoola valley about 1 mile
northeast of Dahlonega, in a wrought-iron syphon-tube (see Plate VIII)
2000 feet in length. The difference in level of the two ends is about
6 feet, and the pressure at the lowest point is 90 pounds per square
inch. The inside diameter is 3 feet, the thickness of the pipe being i\
inch in the upper and f inch in the lower part. It was built in IS 69.
Tour miles from Dahlonega the water is carried across a similar de-
pression in a wooden tube which is -g- of a mile in length and 3 feet in
outside diameter. It is made of 3 by 5-inch staves, trimmed so as to
make a tight fit. These staves are laid in wrought-iron hoops, forming
alternate joints; the last stave is driven in with a maul. This tube was
built in 1868, and is still in good condition.
Auxiliary ditches run off from the main canal to the various mines.
A portion of this water was formerly leased out at the rate of 12 cents
per miner's inch for 24 hours. The present owners, The Hand &
fiM*
N. C. GEOLOGICAL SURVEY.
BULLETIN 10, PLATE VIII.
WROUGHT-IRON SIPHON PIPE (3 FEET INSIDE DIAMETER), 2000 FEET LONG, ON THE HAND
BARLOW DITCH LINE, CROSSING THE YAHOOLAH RIVER. ONE MILE FROM DAHLONEGA, GA.
\
t
i, >,/'i
'*'.;■ J'fJ ••■■**
JM
THE MINING AND MILLING PRACTICE. 109
Barlow United Gold Mines and Hydraulic Works of Georgia, have,
however, been lately using the whole amount in working their own
mines. Besides this system there are several smaller ones, bringing
the total length of ditch-lines up to about 80 miles.
A unique feature of the water-supply at the Findley mine is the
elevation of the water from the ditch-line to a reservoir situated 152 feet
above it, by means of a hydraulic pumping engine made by the Filer &
Stowell Company, of Milwaukee, Mich. This pump is situated near the
stamp-mill, 285 feet below the ditch-line. The water is led to it from
the above ditch in a 16-inch straight-riveted feed-pipe 456 feet in
length, and is discharged by it into a reservoir of 88,000 cubic feet
capacity, a total vertical height of 437 feet, through a 12-inch steel pipe
1141 feet in length. The principle involved is that of the hydraulic
ram, inasmuch as a large quantity of water under a lower head raises
a certain portion of itself to a higher head, the remainder being waste.
The machine, however, is of entirely different and, so far as known,
novel construction. It is of the duplex pattern, the two engines being
-connected by gearing and with an 8-foot fly-wheel. Each engine has 3
•cylinders in tandem, to which the water under the feed-head (123
pounds) is admitted and discharged by valves of the Hiedler type. In
one of these cylinders the water is raised to the greater head (190
pounds) at the expense of the feed-water, under head, going to waste in
the other two. A snifting-valve is attached to the latter to give relief
to the valves. The stroke is 18 inches, and at a high piston-speed of
250 feet per minute the pump works very smoothly. Tests had not
been made, and no figures of efficiency could be obtained at the time of
our visit. Such figures, as well as a more detailed description than
could be made after a hasty examination, would be of great interest.
The present working capacity of the pump is 600 gallons per minute.
MINING METHODS.
The general character of the ore-bodies has already been described (pp.
22 and 23). The depth of the saprolites (decomposed schists) in the
Dahlonega region reaches often to 50 and sometimes 100 feet. Enor-
mous openings have been made in these by the hydraulic giant, whole
sides of the mountain being torn off in places (see Plate IX). The
head employed in hydraulicking varies from 50 to 150 feet, dependent
on the height from which water can be obtained. Where harder rock
"is torn loose, it is broken by hand-sledges and thrown into the ground-
sluices. Powder is sometimes resorted to for breaking down the more
resistant ledges. In order to shorten the distance in sluicing to the
mill, tunnels are often run through the intervening hill- (as at the
Hand and Eindley mines). The wooden sluice-line is supplied with
longitudinal riffles throughout its entire extent.
110
GOLD MINING IN GEORGIA.
In the pursuance of this method a large proportion of the material
carried to the mill is perfectly barren, for the reason that the entire
mass is not gold-bearing, but only certain streaks of it, which cannot be
mined separately by this method.
I
Fig. 16. — Vertical Cross-section of the 450-pound Hall Stamp-mill.
MILLING METHODS.
The Dahlonega method of mining and the milling material resulting
from the same have developed a milling practice particularly character-
istic of this district. The material floated to the mill is of necessity of
small size, the larger pieces of rock being sledged before entering the
flume. Thus crushing is dispensed with. Automatic feeders at the
THE MINING AND MILLING PRACTICE.
Ill
mill have been tried, but were found impracticable, the variable hardness
of the ore (only a small proportion being hard quartz and rock) making
hand-feeding imperative.
The battery which is almost universally in use is that of the Hall type,
invented and patented by Mr. Frank W. Hall, of Dahlonega. The
usual weight of the stamp is 450 pounds. Figs. 16 and 17 give the
two vertical sections of this mill. It represents novel features both in
the battery and in the setting. The long battery blocks and a bed-rock
foundation have been entirely dispensed with. The mill can be set upon
any level piece of ground, a 2-inch plank platform forming practically
the only foundation. The plan of construction (well shown in the
drawing) makes the frame self-contained, the blow of the stamp and the
reaction being absorbed and neutralized in the setting. Elasticity is
maintained by the guy-rods. A suspended platform gives access to the
props, cams, etc. The mortar is held in place by a rib on the bottom
fitted in a corresponding gain in the mortar block. It is held down on
the latter by wedges driven against blocks bolted on the inside of the
battery posts. The small inside dimensions of the mortar are still more
narrowed down by chilled-iron liners, which reach to within an inch of
the dies. The main purpose of these liners is to bring the ore, on being
fed, immediately under the shoes. They also protect the mortar against
wear, and help to some extent in collecting and secreting amalgam.
Quicksilver is fed to the batteries, and in some cases a considerable
amount of amalgam collected is obtained from the mortars. The liners
are fitted with dovetails and lugs at the end, and are finally held in
place by two large keys driven against the screen frame, which is shod
with wear iron on each side. On removing the front liner the mortar
is opened to the floor. The dies, which sit in ^-inch depressions, are
easily withdrawn, the back and side liners drop out, and the mortar can
be cleaned in a few minutes. The whole clean up in a 10-stamp mill
is accomplished in the space of half an hour. The front liner deter-
mines the height of discharge, which, when the dies are new, is about
2 inches. An annealed copper plate, 4 feet long and of the full width
of the mortar, is in most cases considered sufficient for the outside amal-
gamation. The weight of the 450-pound stamp-mill is divided as
follows :
Pounds.
Stem or spindle 175
Head of boss 150
Tappet with keys 50
Shoe 75
Total weight of stamp 450
Die 50
Mortar 2100
; Liners for same 240
112
GOLD MINING IN GEOEGIA.
Fig. 17 — Vertical Longitudinal Section of the 450-pound Hall Stamp-mill.
^J
THE MINING AND MILLING PRACTICE. 113
The average drop of stamp is 9 inches; number of drops per minute,
90. The whole machine is well constructed, and admirably fulfills its
purpose of handling large quantities of the Dahlonega mill-stuff. The
mill is also built with heavier stamps, and some slight changes are made
in the frames of these. None of these heavier mills were seen in opera-
tion; but the setting employed is said to give as great satisfaction as in
the lighter ones. Whether the application of this mill would be exten-
sive for harder ores we are unable to judge. It certainly gives the
extreme of rapid crushing, and might be adopted where such an object
is in view.
The cost of these mills is light and that of installation small as com-
pared with those of Western type.1
Almost all the mills in Dahlonega are operated by water-power, using
turbines of the Lefiel type for large quantities and low heads, and wheels
of the Pelton type when the water is small in quantity under a high
head. The crushing capacity of these mills varies from 2 to 5 tons per
stamp of 450 pounds in 24 hours, depending greatly on the nature of
the material run through.
In hydraulicking, and subsequent transportation by water, a partial
concentration takes place, resulting in the eventual deposition of a
largely enriched product in the mill. The light stuff and most of the
slimes pass through the mill, in almost all cases without subsequent
treatment, and the heavy product' remains, the enriching being all the
way from 2 to 5 times the original value of the ore in place. Besides
this, free gold (generally about one-third of the total amount saved) is
caught in the sluices before reaching the mill. Some of the losses in
this process are evident from the above. Another serious loss, which is
rapidly making itself felt as the mines grow deeper and less decomposed
ores occur, is that of gold in the sulphurets. In such ores that carry
sulphurets at all it is stated that they will run from 2 to 10 per cent.,
the concentrates from which are reported to assay as high as $40 and
higher. Thus far, concentration has not been carried out on a working
1 The following figures were obtained in the camp as representing the average cost of a 450-
pound 10-stamp mill of the Hall type, as erected and used in the Oahlonega district :
All iron-work for batteries and setting, including copper-plates (f. o. b.
works, Cincinnati) $700 00
Freight on same, and cost of erection, about 500 00
Buildings, floors and sluices ' 400 00
Engine and boiler, with connections 600 00
Freight on same, about ■ 150 00
Total cost of complete mill $2350 00
Water-wheel and installation of same would cost about the same as engine and boiler.
Chrome steel (made in Brooklyn, N. Y.) and Wilson pressed steel (made in St. Louis, Mo.) shoes
and dies find about equal favor in the district, costing respectively 6 and 7 cents, f. o. b. works.
Cast-chilled iron shoes are also used to some extent, at a cost of about 3 cents per pound.
Mills similar to the Hall type are also made in Gainesville and Atlanta, Ga.
8
114 GOLD MINING IN GEORGIA.
basis. Despite many inquiries amongst local mill-men and others, we
could hear no reports of losses in amalgamation resulting from so-called
rusty gold. A loss of this nature was in a few cases ascribed to the
finely-divided or flaky condition of the gold.
It is difficult to give any average values of the Dahlonega ores, or in
fact to clearly designate exactly what the term ore applies to in this dis-
trict. Material worth as low as 40 cents per ton has been milled at a
profit. If this figure per ton, plus the gold saved in the sluices (20
cents per ton milled) represents the milling-value of 5 tons of material
mined, as is stated to be frequently the case, then the value of the latter
per ton must have been 12 cents. As a rule, however, the mill-stuff is
of better grade than the above. The actual ore (quartz) is stated to
assay from $1 up to exceptionally high values in the cases of rich
stringers or pockets.
The cost of mining and milling throughout the district will average
from 18 to 25 cents per ton of ore milled.
A description, somewhat more in detail, has been prepared of the
following mine as representing perhaps most perfectly the Dahlonega
method in its original type (of working .soft saprolites or highly decom-
posed material).
DAHLONEGA METHOD AT HEDWIG MINE.
The Hedwig mine is situated near Auraria six miles west of Dahlo-
nega, It consists of a large open cut about sixty feet in depth,
run on a line of siliceous, micaceous ore-bearing schists, sixty feet
in total width. The strike of the sckistosity is N.E. and the dip
60° S.E. Three separate ledges of barren hornblende-gneiss (brick-
bat) enclose two ore-bodies, striking and dipping conformably To them.
But very few small quartz-stringers occur in the mass. \Vater is fur-
nished to the giant (3-inch nozzle) under a maximum head of 60 feet
from a reservoir situated on the hillside above the mine. Six men are
employed at the mine at 80 cents per day (day-shift only).
The material is run to the mill in a flume 2800 feet in length and 14
by 16 inches in cross-section, made of oak boards. It is supplied with
longitudinal riffles made of 2 by 3-inch post oak scantling. The grade
of this sluice is 4 J inches in 12 feet at the lower, and 3^ inches at the
upper end, that is, in the cut where it is not necessary to avoid over-
flows. The outside mill-bin holds about 240 tons, and the material is
flushed from here to the inside bin, which holds 200 tons. Formerly
there were three outside bins and the ore was hauled to the mill in cars.
The mill is a 40-stamp one of the Hall pattern, with a 12-foot driving*
pulley. It is driven by a 4-inch Bidgeway wheel, using 40 inches of
water from two 1-inch nozzles. The water is supplied from the same
THE MINING AND MILLING PRACTICE. 115
reservoir that furnishes the giant at the mine, by an 18-inch spiral' riv-
eted pipe-line, 2880 feet in length, under a head of 226 feet. The
weight of the stamps is 450 pounds; drop 9 inches, 80 times per minute;
discharge 2 inches; round punched screen, 120 holes to the square inch;
length of plates (plain copper) 8 feet in two sections; ten of the stamps
were fitted with silvered plates in 2-foot sections. Only the upper 4
feet of the plates in the mill are kept in shape; it is stated that no gold
was saved on the lower ones. The tailings flow off through mercury
traps. The overflow from both the outside and inside bins runs through
a short line of riffled sluice boxes. At the time of our examination
seven men were employed in the mill in two shifts, at 90 cents per day.
THE LOCKHART MINE, LUMPKIN COUNTY, GA.
The Lockhart mine is situated on the west bank of the Yahoola river
near Dahlonega, Ga, It represents the working of ore-bodies of the
Dahlonega type by underground mining.
The Dahlonega method of mining the saprolites was formerly em-
ployed here, and the old open cuts, now practically abandoned, are of
considerable extent. This is the only mine in the Dahlonega district
where underground work of any importance has been carried on. The
ore-bodies consist of veins of the Dahlonega type (see description, pp. 22
and 23) where the quartz-filling has been more extensive, in places occu-
pying the greater part of the fractured gneiss bands, which in a mining
sense may be termed the vein, the boundaries of the gneiss bands form-
ing continuous, smooth walls, and being the limit of the mineable ore.
The normal strike of the schists at the Lockhart is northeast and the dip
southeast; at one point, however, the schists bend around a mass of
" brickbat," the strike being abruptly changed to the northwest and the
dip to the northeast.
The principal work has been done on the Blackmore vein, where the
country is a biotite hornblende-gneiss. The strike of this vein is E\E. and
the dip 30°-60° S.E. It varies in thickness from 3 to 6 feet. The ore-
body is opened by two adit-levels on the vein, 60 feet apart. The lower
one, which enters the hillside at a depth of about 135 feet below the
original outcrop, has a length of 400 feet, and the ore has been stoped
out between it and the upper level for a distance of 100 feet from the
face, which is the length of the ore-shoot so far as explored. This
shoot has also been worked from the upper level to the surface. The
pitch is steeply to the E~.E. The ores from this shoot mill from $4 to
$5 per ton. Besides this richer shoot the bottom level exposes ore
throughout its entire length. This, however, decreases in quality as the
mouth of the tunnel is approached, where it yields only $1. The system
of work is underhand stoping, stulls being placed 6 feet apart to 1ml. 1
116
GOLD MINING IN GEORGIA.
up the ground. The ore is carried from the stopes in barrows to a
platform at the mouth of the tunnel, from where it is hauled to the mill
by carts.
The same vein has also been opened by a shaft, 50 feet deep, at the
mill house, which is situated about 300 feet N.E. from the mouth of the
mine. A drift 300 feet long was run on the vein here, which is
reported to be 14 feet thick, carrying highly sulphuretted ores, which
milled $4. This part of the mine is now under water.
Other ore-bodies have been opened up to some extent, but not suf-
ficiently to say much of their nature.
The ore is treated in a 20-stamp mill of the 450-pound Hall type,
erected originally for working material from open cuts by the Dah-
lonega method. No crusher or mechanical feeder is used, and no con-
centration of the sulphurets has so far been attempted, although they
are stated to be of high grade. The ore is fed by hand, one man
attending to each ten stamps. The drop is 6 to 8 inches, 60 times per
minute, and the discharge is about 2 inches high. The screen used is
a No. 9 Russia slot. The plates are 6 feet in length, plain copper.
For the hard ores; such as are at present mined, this mill can scarcely
be considered of the best type, being too light. A crusher and auto-
matic feeder would also be applicable here, as well as concentrators and
a subsequent treatment of the sulphurets. The mill-power is furnished
by a turbine wheel, obtaining its head of water from a dam across the
Yahoola river.
The cost of production at the Lockhart is given as follows:
Per ton of ore.
Mining $ .90
Hauling 15
Milling 20
Other expenses 10
Total cost of producing bullion $1.35
The average milling value of the ore for the month ending February
3, 1895, is given as $4.15 per ton. Eo figures of the assay-values of
the tailings could be obtained.
CHAPTEE VI.
MINING, MILLING, AND METALLURGICAL TREATMENT
OF SULPHUKET ORES AT CHARACTERISTIC MINES.
THE REIMER MINE, ROWAN COUNTY, N. C.
This mine is situated about 6 miles southeast of Salisbury on the
waters of the Yadkin river. Geologically it is in the Carolina belt. It
represents a highly sulphuretted quartz-vein of marked persistency,
with smooth walls and a clay gouge, the ore from which is worked by
st^mp-mill amalgamation, concentration of the sulphurets, and chlorin-
ation by the Thies process.
The vein is said to average 3-J feet in thickness, varying from 1-J to
as high as 9 feet. The strike of the outcrop, which has been traced
for 2 miles, is in an east and west direction. The dip is practically ver-
tical. The sulphurets, mostly pyrite with a little chalcopyrite, occur
in bunches, averaging about 10 per cent, of the ore. The quartz is
compact, white and glassy. The wall-rock is a coarse crystalline erup-
tive, probably a quartz-diorite, and a fine-grained phase of the same.
Until 1884, when it was destroyed by fire, a concentration plant was
in operation here. The concentrates which were obtained without pre-
vious amalgamation, were treated at the Yadkin Chlorination works
near Salisbury. Work wTas not taken up again until 1894 and lasted
until the fall of 1895. Fig. 18 gives a vertical section of the mine
along the strike of the vein. The last work was concentrated at the
bottom of No. 1 shaft (1), at a depth of 190 feet. The shaft is poorly
constructed and very wet. A Cornish pump, driven by a belt from the
crank of a small friction-clutch hoisting engine, raised the water from
the bottom into a crude ring at the 150-foot level, from where a No. 9
Cameron sinking pump raised it to the surface. No development work
was carried ahead, the ore being taken out by overhead stoping as soon
as found. It was stated by the management that the poor condition of
the mine and the crude method pursued was due to the more or less
experimental nature of the late underground developments. The size
and substantial construction of the mill and chlorination plant seem,
however, to have gone beyond this stage. On account of the limited
development the mine was worked in three shifts of eight hours each.
with two miners and helpers on each shift, paid respectively $1.50 and
118
GOLD MINING IN NORTH CAROLINA.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 119
$1. The engineer, fireman and top-labor worked in two shifts of twelve
hours each. No definite information could be gained regarding the cost
of mining ; but under the conditions existing, it must have been excessive.
The mill is a 20-stamp one, built by the Mecklenburg Iron Works.1 The
mortar (fig. 19) is of a modified California type, and of medium width
and depth. A novel feature in this mortar is a large opening above
and in back of the screen by which the inside of the screen can be
reached to clear it of foreign clogging matter. The inside plates may
also be taken out through it without disturbing the screen. The weight
of each stamp is 750 pounds, given 5- to 7-inch drop, 90 drops per min-
ute. No inside plates are used at this mill. The height of the discharge
is 5 inches, when the dies are new. The screens are 40-mesh, brass wire.
The outside plates are similar to those at the ITaile mine (see p. 136)
The amount of ore milled was about 1 ton per stamp in 12 hours. About
it of the gold extracted was saved by amalgamation. The tailings from
the plates were concentrated on 2 Frue and 2 Triumph vanners, produc-
ing about 1 ton of concentrates in 12 hours, running from $30 to $40
per ton.
The concentrates were roasted in a large reverberatory furnace located
in the mill building, the area of the hearth being 9x41J feet. The
capacity of this furnace was stated to be 4 roasted tons in 24 hours at a
cost of $1.25 per ton. The furnace was worked in two 12-hour shifts
with two men on each shift, head roaster at $1 and helper at 85 cents.
Two cords of wood, at $1.25 per cord, were burnt in 24 hours.
The chlorination was carried on in a 1-barrel plant with a capacity of
4 roasted tons of concentrates per 24 hours. The building is arranged
for the addition of another barrel which would allow the same work to
be done in 12 hours, giving better opportunity for precipitation, and
reducing the total cost of chlorination. The charge and the method of
working was identical with that pursued at the Haile mine (see p. 140).
1 The Mecklenburg Iron Works of Charlotte, N. C, Captain John Wilkes, Manager, make a
specialty of gold-mining and milling machinery. In the summer of 1895 this company erected
a 5-stamp test mill at their works, connected with a complete chlorination test plant having a
capacity of half a ton of raw concentrates per day. As being of interest and value in a paper
of this kind, we have obtained from them the following list of the cost of milling and chlorina-
tion plants erected in the South. The figures given are outside ones and apply in each case
to a complete automatic plant.
The cost of the machinery for a 10-750-pound stamp mill with grizzly, crusher, self feeders,
silvered inside and outside plates, Triumph concentrators (4 to every 10 stamps), engine and
boiler, together with all attachments, and plans for erecting and locating machinery, is given
at $5700 f . o. b., Charlotte, N. C The same for a 20-stamp mill is $10,350.
The complete cost of a 10-stamp mill as above, set up (in the vicinity), will be about ££000.
Of a 20-stamp mill, about $14,000.
The approximate cost of a 1-barrel chlorination plant with two reverberatory furnaces,
erected, is given at $5500. The same for a 2-barrel plant with four furnaces at $9700.
The complete cost of a 10-stamp mill with concentrators, roasting furnaces and a Thies
chlorination plant with all necessary power and expenses may be figured at $1200 per stamp.
For a 20-stamp mill at $1000 per stamp, and for a 40-stamp mill at $900 per stamp.
The price of shoes and dies of a chilled charcoal iron mixture is 3 cents a pound f. o. b. works.
120
GOLD MINING IN NORTH CAROLINA.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 121
"No satisfactory figures regarding the value of the tailings from either
the concentration or chlorination could be obtained; the figures given
were high as compared with those of other mines. The cost of milling,
concentration, roasting and chlorination per ton of ore milled was given
at $1.80 per ton. This excessive cost, almost three times as much as that
at the Franklin mine, an almost identical case as far as the plant and the
thickness of the ore-body are concerned, must no doubt be greatly laid
to the fact that an attempt is made to supply a plant with a nominal
capacity of 40 tons in 24 hours from a mine, in which the development
does not warrant an output of 10 tons in this time.
The percentage and value of concentrates given above, with the addi-
tion of the gold saved on the plates, gives an estimated value of from
$4 to $5 per ton to the ore mined, without including in this value the
gold lost in tailings. Such an ore if found in sufficiently large bodies
on developing the mine, should pay a profit with the above method of
treatment under a close management.
Experiments were made with cyanide in 1896, but were not successful.
THE FRANKLIN MINE (CREIGHTON MINING AND MILLING COM-
PANY), CHEROKEE COUNTY, GA.
This mine is situated on the Etowah river, about 16 miles northeast
of Canton, the county seat. Geologically it is in the Georgia belt. The
proposition presented here is in most respects similar to that at the
Reimer mine.
The country-rock consists of gneissoid mica- and hornblende-schists,
often garnetiferous. The general strike is !N\ 55° E. and the dip 40°
S.E. Granite dikes are stated to exist in the vicinity of the mine, but
none have been as yet found intersecting the ore-bodies. The char-
acter of these ore^bodies has been described (p. 23). There are two
parallel veins about 150 feet apart, known respectively as the Franklin
and the MacDonald. Of these, the Franklin has been most extensively
opened, and is the only one that has been worked during recent years.
The strike and dip of the veins are, in the main, coincident with those
of the country schists. The mineable ore exists in lenticular shoots or
cylinders pitching 45° 1ST.E. (see fig. 20). Four such shoots had been
opened in the mine within a horizontal distance of about 750 feet on
the strike, at the time of our visit. The largest one of these has a max-
imum length of 120 and maximum width of 14 feet. The average
thickness of the ore-bodies is probably about 3 feet. All but one of the
ore-shoots crop out at the surface, and they show considerable perma-
nency in depth. The 350-foot drift in the mine was extended in a
northeasterly direction about 400 feet beyond the last ore-shoot.
Although a permanent vein with clay casings, and in places heavy quartz-
J22
GOLD MINING IN GEOEGIA.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MIKES. 123
filling-, had been found, the ore was not rich enough to mill. On the
235-foot level a horizontal diamond-drill hole (over 150 feet in length)
was bored in the hanging, but no other parallel ore-body was found.
Cross-fissures, from 3 to 6 inches in thickness, are met with in the mine,
striking 1ST. 30° to 35° W., with a vertical dip, and intersecting, though
not faulting, the ore-bodies. These fissures are filled with coarse crys-
talline calcite, sometimes carrying inconsiderable amounts of pyrite.
The structure of the vein-quartz at the Franklin is banded, and its char-
acter is milky, glassy. The sulphurets consist mainly of coarse crystal-
line pyrite (with very little chalcopyrite), usually occurring in bunches.
Although the ore is over 50 per cent, free-milling, gold visible to the
eye is of very rare occurrence. The fineness of the gold is 980 to 989.
The property of the Creighton Mining and Milling Company com-
prises some 1800 acres. The first work done here was by open cuts in
the outcrop of the ore-shoots. After the death of Mr. Franklin, the
original owner, the mine was worked for a long time by his widow.
Before the adoption of the chlorination process for treatment of sul-
phurets by the present company, a cyanide plant was erected and oper-
ated for a short time.
The present condition of the mine is shown in figure 20,
giving a vertical section along the strike. The mine is worked entirely
through No. 2 shaft (1), driven in the hanging wall to a depth of 215
feet, at which point it strikes the vein. From this level work is carried
on to a total depth of 430 feet by a slope on the dip of the vein and the
pitch of the ore-shoot, resting on a small horse of poor ore.
The method of mining the ore is as follows: Levels are run every
100 feet, and the ore-lenses are entirely stoped out, leaving the inter-
vening bodies of low-grade material as pillars. The levels are con-
nected by a series of raises, their number depending upon the length of
the ore-shoots. The ore is then stoped by underhand work, the raises
acting as ore-chutes (mill-holes), and the cars being loaded directly from
pockets in the level below. No pillars are left below the levels, the
track, when necessary, being carried over the worked-out stopes on stulls.
Only such timbers as are necessary to assist the men in their work are
used, the walls requiring no support. All the material stoped is hoisted
and milled, leaving no waste filling in the mine. Air-drills are used
almost exclusively; for stoping, a Baby Band with J-inch steel is used,
while drifting is clone with 3|-inch cylinder Sergeant machines. The
ore is raised in cars of -J-ton capacity, first up the incline by underground
hoisting engine (4), and then trammed to the bottom of the vortical
shaft, from where they are hoisted to the surface on cages. Xo. 1 shaft
(2) is used for ventilation and as a pipe-way. The mine is not a wet
one, a small steam-pump, situated immediately below Xo. 2 shaft, taking
124 GOLD MINING IN GEORGIA.
care of the water. At the surface, the ore is run over a grizzly and
then through a crusher, the jaws of which are set 1-J inches apart. The
crushed ore is hauled to the mill by mules in cars of 1^ tons capacity,
which are loaded from a bin below the crusher.
During the summer and fall of 1895 two other shafts, No. 3 and
No. 4, located respectively \ and -§ miles southwest of No. 2, were in
progress of sinking, with the object of developing in depth lenses of
ore which had been located and worked to some extent on the surface.
Considerable diamond drilling has been done on the property (some 800
feet in all) at a cost of about $1.25 per foot.
The mill is situated about. J of a mile from No. 2 shaft, on the east
bank of the Etowah river. Water at a head of 7-J feet is supplied to two
turbine wheels by a dam thrown across the river. One of the turbines, a
60-inch Leffel wheel, supplies 23 horse-power to the stamp-mill, while
the other, a 56-inch Davis wheel, drives a duplex Rand air-compressor.
The concentrators are run by steam-power, that derived from the tur-
bine not being of sufficient regularity to secure a uniform product.
There are 20 stamps in the mill, 10 of Western make and 10 erected by
the Mecklenburg Iron Works. Weight of stamps 850 pounds, 7-inch
drop, 70 drops per minute, 6-inch discharge. No inside plates are used
and no quicksilver is fed to the battery (a little coarse gold is cleaned
from the battery sands). The screens are No. 7 slotted Russia iron,
corresponding to about 30-mesh. The outside plates have the full width
of the mortar. They are 8 feet long, arranged in four steps, and are
handled in the same manner as those at the Haile mine. About 55 per
cent, of the gold extracted from the ore is saved by amalgamation. The
ore is fed from bins by Hendey automatic feeders. The mill handles 35
tons in twenty-four hours.
The pulp from each 10 stamps is carried by launders to four hydraulic
classifiers, the overflow from all these going to one slime-spitzkasten of
9 by 9 feet surface dimensions. The product of the 8 hydraulic clas-
sifiers goes to 8 Embrey tables, the product of the slime-kasten being dis-
tributed to 2, making 10 tables in all working on mill-pulp. Besides
these, there are 3 tables working on old amalgamation tailings, assaying
about $3 per ton. The concentrates are not clean, containing about 50
per cent, of sand, but close work would decrease the percentage of ex-
traction. The average amount of sulphurets in the ore mined is about
5 per cent., sometimes running as high as 9 per cent. As high as 5^
tons of raw concentrates are produced and treated in twenty-four hours.
The tailings from concentration run at present about S5 cents per ton,
giving a remarkably high percentage of extraction.
The concentrates are roasted in two double-hearth reverberatory fur-
naces, with a capacity of 2 tons of roasted ore each in 24 hours. Twelve
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MIXES. IZO
pounds of salt per ton are added to the charge to change the carbonate
of lime present to chloride.
Chlorination of the roasted concentrates is carried on in a one-barrel
chlorination plant, the arrangement of the same and the method pur-
sued being identical with that at the Haile mine (see p. 137). The tail-
ings from the chlorination run about 60 cents per ton, giving an extrac-
tion of over 95 per cent.
Labor, Costs, etc. — At the time of our examination about 90 men
were on the pay-roll of the company, when work was going on at full
capacity. The force of men is variable, however, depending upon the
output and the amount of development work. The wages paid were as
follows :
Per day.
Drill runners $1.55
Helpers 1.00
Muckers 75 to 80 cents.
Trammers 1.00
Blacksmiths 2,25
Carpenters 2.50
Three men were employed on each 12-hour shift in the mill and con-
centration house at the following wages :
Per day.
Amalgamator .$1.40
Concentrator 1.35
Helper 75
Boasting. — Two men on each shift, at $1.25. Cost of roasting, per
ton of roasted concentrates, $2.
Chlorination. — One man on each shift. Cost of chloridizing per ton
of roasted concentrates, $1.48.
Supplies. — Timber, $9 per 1000 feet. Cord wood, $1.25 per cord,
8 cords used per day.
Cost per ton of ore mined:
Mining, crushing and tramming to mill $2.051
Milling, roasting and chlorination (J5
Total $2.70
THE HAILE MINE, LANCASTER COUNTY, S. C.-
The Haile mine is situated 3 miles northeast of Kershaw in Lancaster
county, S. C. It is the property of the Haile Gold Mining Company
(New York office, 17 Maiden Lane), Capt. A. Thies, superintendent and
general manager.
1 This figure includes all development work. The average value of the ore ami the concen-
trates cannot be given lor private business reasons.
2 Written in co-operation with Mr. A. Thies.
126 GOLD MINING IN SOUTH CAROLINA.
This mine represents an example of gold mining in its highest devel-
opment in the South, on large bodies of low-grade sulphuret ore.
It is situated in the Carolina belt. ' The country is a siliceous hydro-
muscovite- and argillaceous-schist striking E". 45° to 70° E. and dipping
55° to 85° N.W. The rock is impregnated with auriferous pyrite, free
gold, and in places small quartz-stringers. This is the mass that consti-
tutes the ore-bodies, which are lenticular in shape. Their outline, how-
ever, does not necessarily conform with the strike and dip of the slates,.
but is determined rather by the degree of impregnation. The lenses are
about 200 feet in length and 100 feet in maximum width. The pitch is
50° to 60° N.E., and the dip E~.W. from 45° to nearly vertical. The
country is intersected by a number of diabase dikes, from a few feet to
150 feet in width, striking across the slates at various angles, and in one
instance (Beguelin mine) parallel with them. \Vhere these dikes cross
the ore-bodies they appear to have exerted, in some cases, an enriching
influence on the ore. A short distance to the southeast of the main
workings is the outcrop of a heavy quartz-vein (F., fig. 21) from 10 to
12 feet thick, which strikes parallel to the slates; it is apparently barren.
As explained above, the ore consists of pyritic slates, silicified in varying
degrees, from soft, sericitic slate to very hard hornstone. The more
siliceous ores are usually the richest; graphitic laminae are also good indi-
cations. In the better grade of ore the pyrite exists in a finely divided
condition. Ore containing coarse sulphurets is generally of poor grade.
The crucial test, however, of the value of the ore is the amount of free
gold it contains, which is in direct proportion to that contained in the
sulphurets, and is determined by daily panning. The ore at present
delivered to the mill averages $4 per ton (assay value), of which about
one-third is free gold.1 The percentage of sulphurets in the ores varies
from 2 to 25 per cent.
The first work done at the Haile mine consisted of branch washing
in 1829, which led afterwards to the discovery of gold on the hillsides.
All work was open cutting until 1880, when underground mining was
begun, and this is continued to the present time. Although visible coarse
gold is now of rare occurrence, the mine has yielded some nuggets worth
from $300 to $500 from the decomposed slates in the shallow open cuts/
The first mill was a 5-stamp one, afterwards enlarged to 10, and in
1881 to 20. About 1884 a Blake dry-crushing mill was erected in con-
nection with 20 Embrey tables.3 This was soon abandoned, and the
mine was worked in a dilatory way with the 20-stamp mill until 1S88.
1 Ores as low as $2.75 have been successfully milled.
2 First Annual Report on the Survey of South Carolina for 1856, by O. M. Lieber, Columbia, S_
C, 1858, p. 63.
3 "The Rlake System of Fine Crushing and Its Economic Results,1'' by T. A. Blake, Trans.
Am. Inst. Min. Eny., xvi, 753.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 127
Fig. 21. — Mines and Plant, Haile Gold Mining Co., Lancaster County, S. C. Scale, I
inch=400 feet.
A, Red Hill pits; B, Diabase dikes; C, clay dikes; D, outlet of large reservoir ; E, Bumalo pit ;
F, quartz-vein; G, Beguelin mine; H, Haile pit; K, small reservoir; L, Chase Hill pits; L,
chlorination house; 2, roasting furnaces; 3, boiler house; 4, pump; 5, machine shop; <*>,
No. 2 shaft ; 7, new shaft; 8, No. 3 shaft; 9, offices; 10, superintendent's residence; 11,
mill; 12, concentration house; 13, boiler and engine; 14, crusher; 15, new Beguelin shaft ;
16, Beguelin slope ; 17, boiler house; 18, crusher; 19, flume; 20, mine railroad; 21, com-
missary ; 22, church ; 23, school ; 24, village.
I
128
GOLD MINING IN SOUTH CAROLINA.
Plan,
//
Fig. 22.— Beguelin Mine (part of the Haile Gold Mine). Scale 1 inch — SO feet
D, diabase dikes; S, slate; O, ore-body; 1, new shaft; 2, pillar; 3, pit, 160 feet deep: 4.
inclined shaft; 5, crusher and ore-bin; 6, mine railroad; 7, 22-inch diabase dike; 8.
diabase dike, parallel to ore-body ; 9, old shaft, 50 feet deep ; 10, open cut, 40 feet deep.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 129
During this time, and previously, many unsuccessful experiments for the
treatment of sulpliurets were made.1 In 1888, Mr. A. Tliies took charge
of the Haile mine. He operated the 20-stamp mill until the mine was
sufficiently developed to warrant a larger plant. At this time a 2-barrel
ehlorination plant was added and increased later on to 3 barrels. In
1889 the Blake mill was changed to a 60-stamp, back-to-back mill, with
20 concentrators.
The present workings consist of the Cross (a continuation in depth of
the old Haile and Flint pits, H, fig. 21), and the Beguelin (G, fig. 21)
mines. The Bumalo, Ked Hill and Chase Hill pits (E, A and L,
fig. 21) have not been worked for some time, although in the first there
has been considerable underground work.
Work at the Cross mine Avas stopped in 1888, and all attention was
concentrated on the Beguelin (formerly Blauvelt) mine. Pig. 22 gives
a plan and vertical section of the open pits and some of the underground
workings of this mine. The old workings consist of some shallow open
pits and 3 perpendicular shafts, one 70 feet deep in ore, one 54 feet
deep in the diabase dike (9, fig. 22), and one 70 feet deep in the foot-
wall slates on the southwest side of the dike (not shown). The first of
these was transformed, from a depth of 60 feet downward, into an in-
clined shaft (4, fig. 22), and sunk in the ore-body to a depth of 195 feet.
This shaft was rigged with a self-dumping skip, crusher and ore-bin situ-
ated over the railroad tracks which had been extended to the mine. At
60 feet a drift was run in a northeast direction until the diabase dike was
reached. Meanwhile sinking was continued in the shaft to 120 feet.
From this level drifts were run and connections were made with the
60-foot level, which prepared the ground between them for stoping.
At ISO feet a similar drift was run to the dike and connections made
with the upper levels in such a manner that the ore from the 60-foot
would fall to the 180-foot level, and from there be hoisted to the sur-
face. At 180 feet a drift was started in a southwesterly direction, en-
countering at 64 feet a dike 125 feet thick, through which the drift was
continued to a distance of 600 feet from the shaft. At a depth of 70
feet a similar drift was run and the ore-body beyond the dike was pre-
pared for stoping by connecting these two drifts by several raises. At
the present day all ore on the west side of the dike has been stoped out
to the 180-foot level. To the northeast of the shaft a considerable body
1 "Gold Mining in South Carolina," by E. G. Spilsbury, Trans. .1///. Inst. Min. Engs., xii, 99.
" Notes on the General Treatment of the Southern Gold Ores and Experiments in Matting
Iron Sulphides," by E. G. Spilsbury, Ibid., xv, 767.
"Chlorination of Gold Bearing- Sulphides," by E. G. Spilsbury, Ibid , xvi, 359.
9
•
130
GOLD MINING IN SOUTH CAROLINA.
^ ^ t
Fig. 23.— Plan of Cross Mine (part of the Haile Gold Mine). Scale, 1 inch=100 feet.
B, Bumalo pit ; C, clay dike ; D, diabase dikes ; F, Flint pit ; H, Haile pit ; S, old stope -00-foot
level ; «, No. 2 shaft ; 6, No. 3 shaft ; c, new shaft ; d, bottom of old stope, 160 feet, rising to 100
feet : e, 120-foot level ; /, 200-foot level : g and ht 270-foot level ; O. ore-bodies ; 1. 2, 3 # stop!
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 161
of ore was still standing above the 60-foot level. In order to extract this
ore it became necessary to open the mine from the surface, and the open
pit (3, fig. 22) was started. The gronnd was stripped to a depth of 15
feet, and from that point on the ore, though lean, was used in the mill.
At 60 feet a diabase dike (8, fig. 22), lying parallel to the schistosity
of the country, was encountered in cross-cutting and was at first believed
to represent the hanging wall. On cutting through it, however (a dis-
tance of 4 feet), it was found to merely divide the ore-body. Under the
altered conditions it became necessary to sink a new shaft (1, fig. 22)
in the hanging wall as an outlet for the ore and for pumping. This
shaft was sunk to a depth of 165 feet; connections were made by cross-
cuts with the present inclined shaft and everything prepared for taking
out the shaft pillars, as well as the remainder of the ore. This is the
present condition of the mine. The maximum thickness of the ore-
body at the Beguelin was 80 feet, and the best ore was found between
the two large cross-dikes. A large amount of heavy sulphuretted ores
is at present in sight.
Five hundred feet northeast of the Beguelin mine are several open
pits known as the Chase Hill (L, fig. 21). The character of the ore at
this point is somewhat different, being a banded, colored slate, barren of
sulphurets, but carrying several gold-bearing quartz-veinlets. Taken as
a body it will not make ore.
To the northwest of the Beguelin are several ore-leads as yet un-
prospected.
The 60-stamp mill was run on Beguelin ores three years. The Cross
mine was then reopened (1891). A plan of the Cross mine is given in
fig. 23 showing the open pits and present underground workings, as
well as some of the abandoned ones. After the water had been pumped
out, and the old shaft No. 2 (a, fig. 23), 200 feet deep, was fully
secured, a cross-cut was driven in a northwesterly direction from the
bottom, a distance of 25 feet. A drift (/, fig. 23) was started from
that point in a south westerly direction, reaching ore at a distance of 75
feet from the cross-cut. This drift, on being continued 200 feet, en-
countered a dike 25 feet thick, which was cut through and the drift car-
ried on for 100 feet more. The old workings (d, fig. 23) were also con-
tinued through the dike, the drift (e, fig. 23) on the 100-foot level being
run 100 feet beyond it. Four upraises were driven between these two
levels, two on each side of the dike, opening up 4 large stopes of ore.
This ore ran low in sulphurets, but carried more free gold and furnished
one-half of the quota to the mill. In order to work the ores below the
200-foot level a new shaft (c, fig. 23) was sunk to a depth of 270 feet.
A cross-cut was run from the bottom in a southwesterly direction for a
distance of 75 feet; 15 feet from the shaft a drift (li, fig. 23), parallel to
132 GOLD MINING IN SOUTH CAROLINA.
the drift (/) on the 200-foot level, was carried in a distance of 250 feet.
The dike when encountered was 35 feet thick and no longer decomposed
on the wall, as was the case in the npper level, but hard and solid. By
upraises 4 more stopes were opened. The ore was of a better grade in
proximity to the dike on both sides.
During 1896 an open-cut was made opposite the old Haile pit, in
order to take out the pillars and the ore in the hanging, above the 200-
foot level.
The old workings (S, fig. 23), which were continued from the Bu-
malo pit (B, fig. 23), to a depth of 200 feet, and were for a long time
inaccessible, have been opened up by a diagonal drift from the 270-foot
level (h, fig. 23). Some time ago a northeast tunnel was driven from
the Bumalo pit, at a depth of 50 feet and for a distance of 150 feet, to
a diabase dike 150 feet in thickness, and later continued through this.
Drifts on the further side showed up only barren ground, but good ore
was found from the mouth of the tunnel to the dike, being richest near
the dike. This ore-body was encountered in the 270-foot level with
the drift above mentioned, and the ores are found to be more heavily
sulphuretted than anywhere in the Cross mine.
So far as explorations have gone, 3 different lenses have been encoun-
tered: 1. The Bumalo, furthest northeast; 2. The Haile or middle lens:
3. A small lens 80 to 90 feet west of the Haile (outcrop under the new
boiler-house, 17, fig. 21).
During the summer of 1896 an electric diamond-drill hole was started
in back of the old store building (just to the right of 5, Rg. 21). At
a depth of 58 feet the cores showed ore, assaying as high as $6, and it
appears as though this were in a new hanging wall lens. In order to
solve this question a cross-cut is being driven on the 270-foot level along
the 25-foot dike in a northwesterly direction.
Bed Hill (A, fig. 21) consists of a number of open pits on the north-
west side of the 150-foot dike, where ore was formerly mined to a depth
of 60 feet. It is supposed to be in a line with the Haile lens.
The thickness of these lenses varies, reaching 100 feet in places, while
at others, near the end of the lenses, it is only from 25 to 30 feet.
METHOD OF WORKING; HAILE MINE.
The method of working these deposits is the pillar system (Pfeilerbaif).
illustrated in fig. 24.
The levels (8x7 feet) are run 70 to 100 feet apart, and nearer the
hanging than the foot-wall. At intervals of about 50 feet upraises are
made, with a cross-section of Sx7 feet. These are carried forward at
an inclination as near as possible to 45°. If necessary, the upper portion
through the chain pillar left under each level is carried up vertically.
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES.
133
This raise serves afterwards as a chute (mill-hole). Drifts are then run
below this pillar until the limit of the stope in length (about 30 to 40
feet in all) is reached, leaving a vertical pillar 15 to 20 feet in thickness
between the stopes. The ground is then cut away between the foot- and
hanging walls, completely exposing as roof the bottom of the chain pillar
above, which is sprung in the shape of an arch, with its heavier toe in
the foot-wall and a minimum thickness of 15 feet. This, as well as
all other work in tight ground, is done by air-drills. Stoping is then
carried downward by hand-drilling in circular steps, arranged in such a
manner as to allow the broken ore to drop into the chute, without further
handling. The angle of 45° given to the latter allows a steady flow of
Vertical Section along Strike. Section on X-Y.
Fig. 34.— Method of Stoping at the Cross Mine (Halle Mine). Scale, 1 inch=60feet.
the material down the foot-wall without completely choking it. At the
bottom of the chute is a rough grizzly (a, fig. 24) made of logs, which
holds back the larger boulders and prevents them from choking the
smaller loading pocket below. This grizzly is easily accessible from the
drift, and the larger. pieces of ore are here sledged. The loading-chute
and grizzly are kept up as long as possible, until the stope is finally
broken through to the drift-level below, the ore being shoveled into
cars. As far as possible, the pillars are left in poor ore, the diabase dike
fulfilling this purpose admirably. ~No timber whatever is used, and
although chambers 100 by 100 by 40 feet have been cut out, there
seems to be no danger of a fall, the country-slate being very tough and
self-supporting. The stopes from the 100- and 200-foot levels are con-
nected with the surface by raises, so that at a future date the worked-out
134
GOLD MINING IN SOUTH CAROLINA.
at S
— Y
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 135
stopes can be filled from the surface and the ore in the pillars, i. e., what
is left toward the hanging wall, can be taken out.
Blasting is done with 40 per cent. Hercules powder. One-inch steel
is used for both hand and machine-work. The number of air-drills is
limited by the size of the compressor — an Ingersoll machine, with
3-drill capacity. The ore is carried from the loading-chutes to the shafts
in sheet-iron cars of f-ton capacity, running on 18-inch gauge track.
At No. 2 Shaft (7x12 feet, single compartment) they are hoisted by
cage, with automatic safety catch. The new shaft is 6x14 feet, double
compartment, and the ore is raised by a novel skip designed by Mr.
Thies (fig. 25). The body of the skip, made of sheet iron, has two
projecting lugs riveted to it below the centre of gravity and the bail is
lugged one inch from the vertical centre line.
Each lug runs between a pair of yellow-pine guides set 2 inches apart.
When the skip is raised above the landing-chute two iron pins are
thrown across the openings between each set of guides. The skip is
dropped down on these and the ore is dumped into a loading-chute
placed on the heavier side of the skip. The skip is raised and righted
by the bail, the iron pins are withdrawn by the lander, and the skip de-
scends. The operation is rapid and simple and the cost of the device is
light. The mine is not wet, a No. 9 Cameron pump easily handling the
water.
MILLING AND ORE TREATMENT AT THE HAILE MINE.
The ore is crushed to 1^-inch size in a 10x2 0-inch Blake crusher at the
Beguelin, and a 7x1 0-inch crusher at the Cross mine, and is stored at
both places in bins of 30 tons capacity. The broken ore is hauled to the
mill in narrow-gauge, bottom-dumping cars, holding 3 tons; 8 cars are
run to the trip. The mill bin has a capacity of 300 tons, and is so
arranged that every stamp can be supplied separately with ore, as, owing
to the different character of the ore at the Beguelin and the Haile, it is
treated in separate batteries. A hinged plate, not shown in the accom-
panying illustration, is for this purpose hung at the apex of the bin
floor. A vertical cross-section of the mill is shown in fig. 26. Two ver-
tical sections of a similar battery at the Reimer mine are shown in fig.
19 (p. 120).
The mill is a 60-stamp back-to-back one, 30 on each side, built by the
Mecklenburg Iron Works of Charlotte, N. C. The ore is fed by Hendey
self-feeders. The weight of the stamps is 750 pounds; chilled iron
shoes and dies are used; the stamps drop 6 inches, 86 times per minute,
in the order 1, 3, 2, 5, 4. The crushing capacity is 2 tons to the stamp
in 24 hours. The screens are 30-mesh, made of No. 20 brass wire: these
work well if no cyanide is used in the battery. The average height of
136
GOLD MIXIXG IX SOUTH CAROLINA.
discharge is 6 inches. Amalgamation is accomplished: (1) In the mortar
by a curved front plate attached by means of a wooden chuck-block to
the lip of the mortar, immediately below the discharge ; it is held in posi-
tion by bolts and can be rapidly and easily removed. It present- an
amalgamation-surface of 1.75 square feet and is made of Xo. 7 silver-
plated sheet-copper. The gold being very fine, its accumulation in the
mortar between the dies is insignificant, and the mortar is seldom cleaned
Fig. 26. — Vertical Cross-section of 60-starnp Mill at the Haile Gold Mine.
out. (2) On the outside plates, made of Xo. 12 silvered copper-sheet, and
presenting an amalgamation-surface of 32 square feet to each battery of
5 stamps; they are the full width of the mortar and are arranged in four
steps, each 2 feet in length, and overlapping the next by 1 inch, the
inclination being 2 inches in 1 foot. They are fastened directly to the
battery, the tremor caused hereby being considered beneficial to amal-
TREATMEXT OF SULPHURET ORES AT CHARACTERISTIC MIXES. 137
gamation. These plates are interchangeable; whenever the upper plate
becomes hard and unfit for amalgamation, it is interchanged with one of
the lower plates, thus giving in rotation to each plate a position at the
head of the table. The outside amalgamation-surface of each battery is
further increased by 12 additional square feet, arranged by a drop system
of three plates, the pulp discharging from one to the other before it
enters the main launder. Each battery is provided at the screen-dis-
charge with an impact-plate, not only for amalgamation, but to retard
the velocity of the pulp. They are cleaned from verdigris with a weak
solution of cyanide, and a little potash is sometimes fed into the battery.
Phosphate of sodium is used in the mill to keep the quicksilver bright
and lively. It has been found expedient to remove the inside plates
every 24 hours; as duplicate plates are kept on hand, no delay occurs
while they are being cleaned. The amalgam from these, which is col-
lected and weighed daily, forms an excellent indication of the value of
the ore milled. The amalgam is removed from the outside plates when-
ever it is necessary. A regular clean-up is made only once a month.
About one-third of the gold is saved on the inside plates. The fineness
of the mill gold is 880. The average amount of water used per stamp
is 3-J gallons a minute; and the average consumption of quicksilver is
0.35 ounce per ton of ore. The wear of shoes and dies is 1.3 pounds
per ton of ore stamped. As a lubricant for the cams, molasses thickened
with flour is used and gives excellent results.
The pulp is carried to the concentrators in launders lined with riffles
for a distance of eighty feet. JSTo attempt at sizing the pulp is made,
but the ores from the Beguelin and Cross mines, owing to the differ-
ence in contents of sulphurets, are concentrated separately. The Cross
ore averages about 2 per cent., the Beguelin running from about 7 to
25 per cent, sulphurets. They are milled separately in the proportion of
xV Beguelin and xV Cross, so as to obtain an average of 7 to 8 per cent,
sulphurets from the total ore milled. The concentration is done on 20
Embrey tables (4 by 12 feet), with smooth rubber belts which are set
at an inclination of 2f inches and travel 5 feet per minute, receiving at
the same time 192 percussions. The concentrates contain 90 per cent.
pyrite, which is pure sulphide of iron with occasional small traces of
arsenic. The loss in concentration is 15 to 20 per cent. The averag<
value of these concentrates is $25 to $35 per ton.
Chlorination. — The concentrates are hauled on the mine-railway to
the chlorination plant. They are roasted in two double-hearth rever-
beratory (see fig. 27) and one revolving pan-furnace, the sulphur being-
reduced from about 43 to as low as -J per cent., and the value of the
material being increased by -J. Each double-hearth furnace is worked
by two men to a shift of 12 hours, the output being 2 ton- of roasted
138
GOLD MINING IN SOUTH CAROLINA.
«^R
P^5£3
Irf
#-+
if I
H* §
:i
TREATMENT OF SULPIIURET ORES AT CHARACTERISTIC MINES.
139
concentrates per 24 hours for each furnace. The revolving pan-furnace
is worked by three men per 24 hours, with the same output as the double-
hearth. The fumes from these furnaces carry off into the air the equiv-
alent of 13 tons of 50 per cent, sulphuric acid. The management has
investigated the erection of lead chambers, but so far have not consid-
ered such an installation to their advantage. The Spence furnace has
Fig-. 28. — Cliloriuation plant at the Haile Gold Mine. Vertical Longitudinal Section.
been tried at the Haile, without success.1 The roasted ore after cooling
is elevated to the top floor of the chlorination house, 82 feet high. This
consists of a four-story frame building, containing 3 chlorination-barrels,
11 filtering-tanks, 2 storage-tanks, and 13 precipitating vats (see figs.
28, 29). The ore is charged through a hopper into the chlorination-
lSee paper by A. Thies and W. B. Phillips, "The Thies Process of Treating Low-grade
Auriferous Sulphides at the Haile Gold Mine, Lancaster Co., S. C," Trans. Am. Inst. Mill. Eng.,
xix, 601.
■HM
.
140
GOLD MINING IN SOUTH CAROLINA.
barrels (see fig. 30) by cars holding 1 ton each. The barrel is 60 inches
long by 42 inches in diameter, made of cast-iron and lead-lined (12
pounds of lead to the square foot). It also contains a lead valve in
order to ascertain whether the necessary amount of free chlorine is
present. (The use of this valve is unnecessary after the character of
the ores becomes known).
Fig. 29. — Chlorination Plant at the Haile Gold Mine. Vertical Cross-section.
The full charge consists of 120 gallons of water (to make an easily
flowing pulp), from 8 to 11 pounds of bleaching powder, then the ore,
and finally 12 to 15 pounds of sulphuric acid. The barrel is hermeti-
cally closed and revolves for about 3 hours at the rate of 15 to IS revolu-
tions per minute. (A 5 horse-power engine performs this work and
also the elevating of the ore.) The barrel is then inverted, opened and
discharged through a lead-lined semicircle in the floor to a filter on the
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MIXES. 141
Fig. 30.— Chlorination-Barrel, Haile Gold Mine. The upper Bgure is a vertical cross-
section, and the lower a vertical longitudinal section. Inside dimensions: Diameter,
42 inches ; length, 60 inches.
142 GOLD MINING IN SOUTH CAEOLIXA.
floor below. There are 4 lead-lined filters to each barrel, their
sizes being 6 by 8 feet by 18 inches deep in front and 17 inches in back.
The bottom is covered with mineraline 1 tiles 12 by 12 inches by 1 inch
thick, perforated and having -J-inch gutters underneath; on top of these
is placed a rack of lj-inch wooden slats, 4 inches high and 8 inches
apart; the first layer above the tiles consists of 4 inches of coarse quartz
pebbles (-§• to -J inch size), and this is covered by from 1 to 2 inches of
ordinary clean sand. Before emptying the contents of the barrel, the
filter is flooded with water to the level of the top of the filter-bed to act
as a cushion. Then the original solution is passed through, striking on
a float to prevent breaking the filter-bed. The ore-pulp is washed twice
with clean water; the first time enough is added to stand 4 inches above
the surface of the pulp, and the second time the tank is entirely filled.
This amount is found sufficient to thoroughly remove all traces
of chloride of gold from the pulp (tests are made with TeSOj. The
filtered solutions are stored in two stock-tanks on the second floor, and
are drawn off from these into the precipitating-tanks as required. The
latter are S feet in diameter and 3 feet high, made of wood, the interior
coated with asphalt. They are provided with three outlets, the upper
one IS inches from the top, the middle one 1 inch above the bottom and
the lowest one in the jamb. The gold is precipitated in the metallic state
with an excess of fresh ferrous sulphate, made in a small lead-lined tank.
Tn warmer weather 48 hours suffice for settling, and in colder weather
from 3 to 4 days. The supernatant liquor is drawn off through the two
upper outlets, opened one after the other (in order to prevent auy stir-
ring of the precipitates), and passed through a box filled with sawdust
to catch any precipitate. The gold precipitate is drawn from the tanks
through the jamb-opening into a small lead-lined settling-tank 2 by 2 by
4 feet. After standing 24 hours the supernatant liquor is siphoned off,
and the precipitate filtered on paper. This is dried and mixed with
about half its weight of borax and soda in almost equal proportions.
Should iron salts be present, a little quartz sand is added. It is melted
in graphite crucibles and cast into ingots of about 990 fineness. The
whole operation is so simple that the most ordinary laborer can acquire
the mechanical knowledge in a day. The repairs are practically nil.3
LABOE, COSTS, ETC., AT THE HAILE MINE.
Some of the figures of costs of labor and working at the Haile mine
are given below. For private business reasons it is impossible to give
these as fully as we should like to.
1 A melted mixture of sulphur and quartz.
2 The Thies chlorination process has been described'in detail by T. K. Rose, in his Metallurgy
of Gold, C. Griffin & Co., London, 1894.
.'
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 143
Mines. — Cost of Labor:
Per day.
Holders $ .90
Strikers 1.10
Machine-runners 1.25
255 cords of wood at $1.50, burned per month.
Mill (2 shifts of 12 hours each).— Distribution and Cost of Labor:
One superintendent $
" laborer (amalgamation) per shift 2.50
1.00
(concentration) " 1.25
SO
" fireman per shift ., 1.00
" engineer per day shift 1.75
" per night shift 1.50
150 cords of wood at $1.50, used per month.
Repairs (wear of shoes and dies, etc.), 4 cents per ton of ore.
Roasting and Chlorination.— Distribution and Cost of Labor:
Roasting furnaces, producing 6 tons of roasted concentrates
per 24 hours; six men, day shift, each $1.00
Five men, night shift, each 1.00
3 cords of wood at $1.50. used per 24 hours.
Chlorination (1 shift of 12 hours) working 6 tons of roasted concentrates:
Two men, each at $1.00
One man at 1.25
Cost of roasting per ton of roasted concentrates:
Labor $1.83
Fuel 75
$2.58
Cost of chlorinating 1 ton of roasted concentrates:
Labor $ .50
Foreman 20
Power 12
Sulphuric acid for FeSo4 06
11 pounds of bleaching powder, at iy2 cents 27%
15 pounds of sulphuric acid, at 1 cent 15
Wear and tear 10
Superintendence 05
$1.45Vo
Cost of roasting and chlorination per ton of raw concentrates. .$3.02
Cost of roasting and chlorination per ton of ore mined 19
Percentage of Extraction:
Mill: Tailings from concentrators 85 to 90 cents.
Showing a yield of 75 to 80 per cent.
Chlorination: Tailings as high as $1.50
Average yield 94 per cent.
141- GOLD MINING IN SOUTH CAROLINA.
THE BREWEE MINE, CHESTERFIELD COUNTY, S. C.
The Brewer mine (the De Soto Mining Company) is situated on
Lynch's creek, about 13 miles by road northeast of Kershaw, the nearest
railroad station; it is about 8 miles (air-line) northeast of the Haile mine.
The mining problem presented here is the working of large bodies of
low-grade, sulphuretted ores by quarrying, milling, concentration, and
chlorination.
Geologically, the mine is situated in the Carolina belt. The country-
rock is a hard, de vitrified acid volcanic (probably quartz-porphyry ) . of
a light bluish-gray color, resembling hornstone or chert. It is in part
sheared into sericitic schists, similar to the slates at the Haile mine,
though more highly silicified. Masses of coarse, pyroclastic breccia
were found in the bottom of the large mine-pit, but the rock was not
observed in place. The strike of the siliceous schists is very much con-
fused, being in all directions; the normal strike is probably something
like !N". 70° E., and the dip 60° "N.~W: [Numerous coarse-grained granitic
dikes (Gr, fig. 31) intersect the country, and the local abnormal strikes
and dips of the schists may be due to their intrusion. These rocks
occupy an elevation known as Brewer hill, which rises some 200 feet
above the level of the main drainage basin, Lynch's creek on the east
and Flat creek on the west. A heavy diabase dike lies on the west bank
of Flat creek, and to the west of that, the country-rock is granite.
The ore-bodies at the Brewer are similar to those of the Haile mine,
being auriferous pyritic impregnations in the country-rock, and assum-
ing more or less lenticular forms. Free gold appears as thin films or
coatings on the cleavage- and joint-planes of the schists. The ore-bearing
rock is decomposed, in certain streaks more than in others, to the deepest
workings of the mine, 150 feet, resulting in soft, friable masses which
disintegrate into finely divided white sand. Certain portions of the
deposit are richer in gold, and these also have an imperfect lenticular
shape, from 10 to 30 feet in thickness (O, fig. 31). These better
grade ores will run from $5 to $7 per ton, assay value, while the average
run of the mine is in the vicinity of $3. The fineness of the gold is from
070 to 984. The total width of the ore-bearing ground is stated to be
800 yards. The main ore-body has been opened for a distance of 600
feet in a north and south, and 250 feet in an east and west direction.
The sulphuret contained in the ore (finely divided pyrite) averages
about 7 per cent of the total mass. In one portion of the mine
enargite (and perhaps also covellite) appears in some quantity, but its
occurrence is local. Other sulphurets occur in small quantities, but are
interesting merely from a mineralogical standpoint. Tinstone (some-
times in direct association with gold) has been found in hydraulicking
TREATMENT OF SULPHTJRET ORES AT CHARACTERISTIC MIXES. 145
at the Tan-yard deposit; and pyrophyllite occurs as an alteration pro-
duct in the granitic dikes.
The ore itself is practically devoid of auriferous vein-quartz. Small
reticulated fissures filled with barren quartz intersect the country; and
in the Tan-yard (an old gravel-channel to the east of the mine) a large
barren quartz-vein, 5 to 20 feet in thickness, is to be seen.
The Brewer mine, probably one of the first developed in South Caro-
lina, was opened in 1828 by shallow pits in the saprolites and in the
gravels of the Tan-yard, the material being worked in rockers. This
work continued until 1857, and it is stated that in various years during
this period as many as 100 to 200 hands were employed at one time, mak-
ing $1.50 to $3 per day each, and paying nearly 30 per cent, royalty.
From 1857 to 1862 Commodore Stockton mined and milled the ore in
arrastras and Chilian mills. Up to 1879, when the Brewer Mining
Company took hold of the property, there seems to have been a lull in
the activity of the operations. In this and succeeding years the old
Tan-yard placer was reworked by hydraulicking. This deposit is an
old river-channel, and was extensively worked in former days, being,
in fact, the site of the first discovery of gold on the property. The
width of the channel is from 200 to 300 feet, and its length about 1-J
miles; it is now intersected by a large valley. The original overlay was
about 6 feet, and the gravel from 3 to 6 feet in thickness, underlain by
a thin bed of compact conglomerate, cemented by iron oxide; the bed-
rock is a siliceous sericitic schist. The old miners in working this
■deposit did not wash the overlay, nor did they take up any part of the
bed-rock. In reworking, the whole mass (from 5 to 20 feet in thickness)
was hydraulicked, and as much as 4 to 5 feet of the loose bed-rock was
also torn up. Water was pumped about 200 feet in vertical height,
from Lynch's creek to a small reservoir situated at the head of the placer,
from where a portion of it was delivered to the giant (2-J-inch nozzle),
by a force-pump under a pressure of 80 pounds, and the remainder run
directly through the ground-sluices to carry off the tailings. Six men
were employed in cleaning bed-rock, and two at the sluices. It is stated
that a handsome profit was realized by this work.
In 1885 a 5-stamp mill was erected and run on ores produced in
prospecting work. In 1887 an adit-level (A, fig. 31), 1200 feet in
length, was driven into the hillside under the main ore-deposit, and the
mine was opened from below by a raise, which was at the same time
used as a chute, connecting with the open pit above. The stoping was
carried on overground, and the material taken out through the tunnel.
In 1888 a 40-stamp mill was erected, and started up in May, 1889. A
Thies chlorination plant was added in 1892, and operated for a short
time during 1893. From that date until June, 1895, the mine was idle,
but at that time preparations were being made for starting work again.
10
146
GOLD MINING IN SOUTH CAROLINA.
Figure 31 represents the plan of the Brewer mine as it is at
present developed. It consists of the large open pit (P), 150 feet
in depth, about 200 by 250 feet on the surface, and 100 by 180 feet in
Fig. 31. — Plan of Brewer Mine, Chesterfield County, S. C. Scale, 1 inch=120 feet
A, adit-level, 1200 feet long ; C, north cut, 10 feet deep; D, drift, 150-foot level: G,.
granitic dikes ; O, streaks of best ore ; P, bottom of main pit, 150 feet deep ; W, west
cut, 50 feet deep ; a a, surface line of open cut; b b, 150-foot level.
the bottom. The ore-body has been further explored by a drift (D)r
on the bottom level, extending 430 feet in a northerly direction, and
being in ore all the way. The tunnel (A) is laid with narrow-gauge
N
*
-
/
TREATMENT OF SULPHURET ORES AT CHARACTERISTIC MINES. 147
track, over which the ore is hauled to the mill by a small locomotive.
This tunnel is drained by a wooden gutter situated in the center of the
track line. At present ore is being quarried in the west cut (W) near
the surface, from where it falls to the bottom of the pit (P), and is hauled
to the mill through (A). The 40-stamp mill, which was not in oper-
tion when visited, is situated about a quarter of a mile east of the mine,
on the west bank of Lynch's creek. It is of the Western type, built
by Eraser & Chalmers. The weight of the stamps is 900 pounds. The
mortars are 15 inches wide at the lip, and are fitted with front inside
plates and 30-mesh steel wire screens. The outside plates of silvered
copper are 8 feet long by 54 inches wide. Below the plates is situated
a line of pointed boxes, serving simply as amalgam-traps, which dis-
charge 2 feet above the bottom to four Frue vanners with 6- by 14-foot
belts. This is one of the most substantial and best constructed mills in
the South. (Plate X.)
The chlorination plant consists of 2 revolving-pan furnaces, 2 barrels,
8 filters, 2 stock-tanks, and 8 precipitating-vats of the same construc-
tion and arrangement as at the Haile mine (see pp. 139-142).
When the mill was last operated (in 1893), the object was to put
through as much material as possible; 5 to 6 tons of ore per stamp were
milled in 24 hours, with 4-inch drop, 90 drops per minute, crushing
through a 20-mesh screen. Naturally, the pulp flowed over the plates
without a large portion of it coming in contact with them; and, with
only 4 vanners, the ultimate loss in tailings was so great as to leave little
if any profit. The concentrates that were obtained ran from $15 to $20.
About 50 per cent, of the gold in the ores is free, and of the amount
saved in amalgamation 50 per cent, was in the battery and on the inside
plate. The cost of mining and milling at the Brewer mine, as prac-
ticed above, is given at 75 cents; and the total cost (including mainte-
nance, salaries, etc.) at $1 per ton of ore mined.
Laboratory experiments with cyanide, and others with chlorination
in bulk (the latter by Mr. P. G. Lidner), have been tried at the Brewer,
but proved unsuccessful. In the latter part of 1895 cyanide experi-
ments were again undertaken with reported favorable results.
CHAPTER VII.
SOME CONCLUSIONS CONCERNING GOLD MIXING IN
NORTH CAROLINA AND ADJACENT SOUTH
APPALACHIAN REGIONS.
Bonanzas, in the general meaning of that term, have not been found
in North Carolina nor in the adjacent1 South Appalachian regions, and
probably never will be, unless we except rich pockets of limited extent
which for a time might prove to be such to the individual operator or
tributor. The "Western saying that " A good gold mine is one which
will pay dividends under poor management/' would exclude all South-
ern gold mines from even this distinction. There are, however, a few
mines in the south, notably the Haile and the Eranklin, which, under able
management, fully conversant with all the requirements and exigencies
of the case, have been developed into remunerative business enterprises.
The wide distribution and the variety of the auriferous deposits through-
out the South do not preclude the possibility of these mines serving as
examples for a larger number of operations, instead of being isolated
cases as at present.
By far the greater portion of the gold that has been produced in the
South was derived from the placers, including bottom and sidehill
gravels, as well as auriferous saprolites and decomposed vein out-
crops. From such deposits the cream has been worked off, and
what remains are the old gravel heaps and such virgin ground as
in the earlier days proved inaccessible to water and unprofitable for
primitive methods, or was overlooked by the prospectors. Of the latter
class the Crawford mine, described on pp. 91—95, is an example. Al-
though the earlier prospecting for gravel deposits was carried on in a
thorough manner, there were no doubt large plantations on which such
work, especially in the fertile bottoms, was not countenanced. It is also
probable that deeper lying gravel-channels, of which there are no indi-
cations on the surface, remain to be exploited, as, for instance, in the
South Mountain and Dahlonega districts. The installation of pumps
(or where these have been unsuccessfully used, the erection of improved
or more economic plants), as well as more thorough and extensive sur-
veys for ditch lines, may open up much ground which was formerly in-
accessible to water. Hydraulicking under direct pressure from a pump
may in many cases be feasible, and may prove more economical as far as
plant is concerned.
SOME CONCLUSIONS CONCERNING GOLD MINING. 149
Bottom-gravel mines were operated in the earlier days almost entirely
by pitting, draining the excavations with water-wheels, and raising the
gravel by hand to rockers and sluice-boxes, the tailings being left in
large heaps. This work was often done in an unsystematic manner;
portions of the ground could not be worked at all; and, in general, only
the richest gravel received attention, the overlay and the bed-rock being
neglected entirely. Some of these gravel heaps have frequently been
reworked, in one case (on the Mills property, N. C.) as often as seven
times. The additional gold obtained in these operations was partially
due to the incompleteness of the preceding washings, as well as to the
subsequent further disintegration of vein-quartz carrying free gold and
sulphurets. A number of these old bottom-placers may warrant a re-
munerative reworking on a large scale, either by the use of giants and
bed-rock sluices when sufficient fall is available, or where the latter
is not the case (a common feature in the South) by the application of
the hydraulic gravel-elevator.
Virgin placer deposits a] so exist, which, on account of the low grade
of gravel, or the great depth of the overlay, could not be profitably
worked by the more primitive methods. Tor such, the above appliances
may also furnish a solution. The Southern gravel deposits are far less
extensive than those of California and New Zealand, and therefore as
low a grade of gravel cannot be worked, although the South has cheaper
labor in its favor. Systematic work has rarely been pursued, and rec-
ords of such work have not been kept. Tor this reason, as well as on
account of the unequal concentration of the gold in the deposits and the
varying working conditions met with, it is impossible to give limiting
values per cubic yard to guide operations in the future. Tor the same
reasons, preliminary testing will be difficult, especially in ground that has
already been worked.
In general, it may be said that the great extent of the rock-decompo-
sition in the South (often from 25 to 100 feet in depth), and the easy
disintegration of the same has resulted in a greater concentration of gold
in the gravel, considering the richness of the ore-bodies in place, than
in many other gold fields.
The auriferous saprolites and decomposed vein-matter have been most
extensively worked in the Dahlonega district. Here the decomposed
material, in which gold from the eroded vein-matter is more or less con-
centrated, has to a great extent been worked clown to the harder rock.
In the Dahlonega method of working, everything seems to have tended
towards the simplification of the process and plant, with the object of
milling as large an amount of loAV-grade material as is possible with
economy in labor and plant, irrespective of close working. Both on ac-
count of the greatly impoverished material and its increasing unfitness
_
150 GOLD MINING IN THE SOUTHERN APPALACHIANS.
for disintegration with the giant, a limit to this method of mining must
ultimately be reached here. The ore-bodies continue in depth and should
open up a probably more productive field in deep mining, with less loss
of gold and more economical output.
Although the Southern gold field has been known and worked since
the beginning of the century, it has not had the benefit of such thor-
ough and systematic vein-prospecting as most of the later discovered
fields. It was already a well-settled farming country, generally owned
in large plantation-tracts, when gold was first sought after; and such
lands as were unoccupied were the property of the State governments,
which did not offer special privileges and inducements to the develop-
ment of the mining industry. Hence the Western system of mineral
lands and mining claims did not exist, and the field was not opened to
the individual professional prospector. The same condition practically
exists to-day. It is difficult to make satisfactory arrangements with the
property holders for prospecting; and propositions for such work from
outsiders are as a rule regarded with suspicion. Even the larger tracts
owned at present by mining companies have not been prospected to any
extent. A notable exception to this is the development work carried
on by the Yonah Land and Mining Company in Georgia. If this ex-
ample were followed by other mining corporations whose acreage runs
into the thousands while their operations are limited to a few square
rods, it would greatly help to develop the possible gold resources of the
South in the direction of new discoveries. We do not, however, wish
to give the impression that larger and more valuable ore-deposits than
those already exploited are still to be found; the more easily recognizable
and richer outcrops have been worked over, and in any case such finds
as may be made will probably present no new features.
In general, the abandoned mines present the same features as those
that are working. Judging from some of the older reports (Silliman,
Rogers, Emmons, etc.), the surface ores of these mines were very rich.
due partially to local concentration near the surface from the eroded
portions of the vein, and in other cases perhaps to pockets and shoots
of limited extent and depth. In the earlier days, few of the veins
were worked below the water-level; the abandonment of these older
mines, cannot, however, always be laid to the appearance of refractory
sulphurets. In the sulphuretted ores worked to-day from 20 to 60 per
cent, of the gold is free, and in many of the earlier mines, where rich ores
occurred in continuous shoots, these were followed down far below the
water-level and the free gold which they contained was obtained by
simple amalgamation, as for instance at the Gold Hill mine in Xorth
Carolina, where the workings extended to 740 feet in depth. The more
plausible reasons for the abandonment of the so-called rich Southern gold
SOME CONCLUSIONS CONCERNING GOLD MINING. 151
mines may be attributed to the pinching out of the ore-shoots outcrop-
ping at the surface or a diminution in the assay value of the ore. It
is probable that the more expensive and difficult operations at such
depths precluded the further search for other ore-bodies below the water-
level. It must also be remembered that as early as 1840 at least par-
tially successful attempts were made to work sulphurets.
In many of the mines, however, the ore-bodies were of low grade,
though sometimes of large extent, and the small extraction of the free
gold in the sulphuretted ores did not permit of a profitable continuation
of the work. As in all mining regions, many other so-called plausible
reasons are given for the abandonment of the mines, as, for instance,
mismanagement, disputes among the owners, etc.
To determine the probable value of a mine an examination is of course
absolutely necessary. A conclusive opinion is, however, in most cases
impossible, even after the mine has been pumped out and examined, on
account of the poor condition of the workings and the, at best, limited
exposures of the ore-bodies. The prospective investor must, with few
exceptions, bear the cost of the necessary exploratory development,
which expenditure must be considered speculative. A great number
of the properties are held at prohibitory figures, and arrangements for
satisfactory examination under option or otherwise cannot be made,
traditional merit and output being considered a sufficient proof of value
by the owners.
In low-grade highly sulphuretted ore-bodies assays may give a fair
indication of the value of the ore if the samples be fairly taken; but a
test on a larger scale at one of the experimental chlorination plants,1 in
cases where it is intended to subsequently adopt the chlorination process,
would be much more conclusive.
On higher grade, free-milling ores, however, assays, even if taken
with care, will be of little value; the results will, in fact, often be mis-
leading. In such cases a mill-test is imperative, and it can generally
be made either in the mill at the mine itself, at some neighboring mill,
or at test mills especially operated for this purpose.2
The most feasible propositions in the South appear to be the work-
ing of the larger low-grade ore-bodies. Rich veins as a rule have been
in pockets and of small extent, more suited to the operations of tributors
or small landowners, with the help, perhaps, of the wooden stamp-mill.
It is a well-known fact that ore-deposits of this uncertain character can-
not be worked systematically by larger companies with an extensive
plant, and must be left to the individual miner, whose persona] success
pays his daily wages, and to whom an occasional strike is an induce-
ment for continuous work.
Captain A. Thiee, Haile Mine, S. 0., and Mecklenburg Iron Works, Charlotte, X. C.
2 Mecklenburg Iron Works, N. C, and the Salisbury Supply Co., Salisbury, N. U.
152
GOLD MINING IN THE SOUTHERN APPALACHIANS.
Systematic work can only be pursued where the ore-bodies are large
and continuous enough to warrant the establishment of a regular plant
for mining, milling and reduction of the ores. The question of quantity
means more than that of quality, so long as the former does not fall
below a certain limit.
Among such may be classed the wide lenticular bodies of auriferous
and pyritic slates, as at the Haile and Russell mines, and the persistent
and continuous quartz-veins of sufficient width, such as at the Reimer
and Capps mines. The more continuous and stronger ore-leads of the
Dahlonega type may also be included here, such as at the Lockhart and
the Franklin mines, which are at present being worked as deep mines,
as well as those which have so far been worked by hydraulic-king, like
the Hand, Singleton, Findley, etc., mines.
In some localities smaller or irregular quartz-veins lying close to-
gether have been worked separately; it may prove feasible to mine these
together as a body of low-grade ore, especially where the intervening
and adjoining country-rock is to some degree auriferous, as at the Rocky
River mine.
Such ores as are alluded to may be said to average between $3 and
$7 per ton. There are exceptional cases of richer ore-bodies which have
shown considerable continuity, as, for instance, at the Phoenix mine;
but here, as is usual, the size of the vein and hence the quantity of the
ore decreases proportionately with the improvement in the quality.
Almost without exception, a profitable extraction from Southern gold
ores can only be attained by supplementing amalgamation with con-
centration of the sulphurets and by subsequent treatment of the latter.
The practically universal adoption of the stamp-mill in the South verities,,
as in other gold-mining regions, its more general applicability for crush-
ing compared with other machinery. The two types of stamp-mills more
especially characteristic of the South, each having its own field of action,
have been described on pages 111 and 119. The milling practice varies
greatly, as might be expected from the extremely variable character of
the ores.
All of the Southern ores contain at least a portion of their gold in
the free state, and excepting where other ingredients offer serious ob-
stacles, or where a smelting process is intended, concentration is best
preceded by amalgamation, so as to obtain the free gold as soon as pos-
sible and not endanger it to loss in subsequent treatment. Especially
where the sulphurets are coarse and the crushing is not fine, a prelimi-
nary sizing in hydraulic classifiers and spitzkastens, and the treatment
of each size on a separate vanning machine, is advisable. There has
been a tendency to overcrowd these machines in the South; a saving of
original cost here is but poor economy. It would seldom be advisable
SOME CONCLUSIONS CONCERNING GOLD MINING. 153
to use less than two 4-foot belts to every five stamps. The degree of
concentration (cleanness of the concentrates) must depend upon the ratio
between the cost of subsequent treatment per ton, on the one hand, and
a greater loss in tailings occasioned by close concentration on the other,
the cost of concentration itself being practically the same in either ex-
treme.
For the economical treatment of the concentrates chlorination by
the Thies process furnishes in almost all cases a ready solution. The
process is a simple one and is not patented; the cost of plant is com-
paratively small, and the percentage of extraction is high (94 to 97 per
cent.). It has been in active operation on a continuous working scale
at the two most successful mines in the South (Haile and Franklin
mines). The presence of copper is objectionable in this process, as it
increases the consumption of chemicals, and if in too large a quantity
it may preclude the adoption of the process. At the Phoenix mine, N.
C, ores running as high as 3 per cent, copper were, however, success-
fully treated. Ingredients which make dead-roasting difficult may also
add to the cost of the process.
Sulphuret ores assaying only $3 per ton, when existing in exten-
sive bodies, so as to permit operations on a larger scale, other condi-
tions being favorable, might be worked at a profit by the application
of this process.
Should concentration, on account of the too finely divided condition
of the gold and sulphurets, prove impossible without a heavy loss in
tailings, the cyanide, bromination or Swedish chlorination process might
prove of value for a direct treatment of the ore; or the ore might be
treated in bulk by the modification of the Thies process in use at Dead-
wood, Dakota; or by the Thies process proper on an enlarged scale,
using, if necessary, closed filtering-tanks under pressure. In all of the
above previous roasting is necessary, excepting perhaps in the cyanide
process. Attempts with the latter have so far been unsuccessful. It
will be of interest to watch the outcome of the plant at the Russell mine,
K". C. Lack of success in the use of cyanide cannot always be laid to its
lack of applicability; it certainly has, however, this disadvantage, that it
requires a careful experimental trial, best made on a large scale and
therefore expensive, as well as a continuous supervision afterwards by
an experienced chemist, together with more or less skilled assistance,
which is a requirement not always conformable with Southern con-
ditions.
A small class of the Southern ores, referring particularly to those con-
taining lead, copper and zinc, would have to be treated by -inciting. A
smelting plant would, however, only prove a financial success under the
concerted action of all — or at least most — of the mine- producing such
_
154 GOLD MINING IN THE SOUTHERN APPALACHIANS.
ores, a state of affairs which, under the present condition of gold mining
in the South, seems difficult to attain. Several attempts have been made
to gain this end, but have not been successful.
Taken as a whole, the gold ores of the Southern Appalachians present
no greater difficulties of treatment than those of other fields, the dis-
tinguishing feature being perhaps their large variety, which makes a
close study of each separate ore-body necessary.
As to the cost of labor in the South, it may be said that while it is low
compared to that of the Western mining districts, and unskilled labor
can be obtained at especially low cost, skilled labor commands about the
same wages as throughout the East. It will be found here, as in other
places, that the laborer is worthy of his hire. Some difficulty may be
experienced in obtaining suitable labor, especially in those districts
where no active mining work has been going on. In general there are
no mining camps, in the Western sense of the word, and hence no regular
mining population that might otherwise engender a more energetic min-
ing spirit.
Among the facilities for operations in the South are the climate,
which permits continuous working throughout the year: the accessibility
of the mines to railroad lines, and their comparative proximity to in-
vesting Eastern capital. Lumber, timber and cord wood can be obtained
at very low cost. Mining supplies and machinery are furnished from
several central points in the field (Salisbury, Charlotte, Daklonega,
Atlanta). Water-power — in most cases, however, undeveloped — is
abundant throughout a great portion of the mining belt. Should a
revival in mining favor a development of properties in groups, central
electric power distribution plants would be practicable in most districts.
Gold mining in the South has its favorable features, which should
facilitate the economic working of the ore-deposits as legitimate business
undertakings, with close and intelligent management. A considerable
number of properties are at least worthy of investigation, and to the
best of our belief, such investigations will disclose remunerative working
opportunities, and will ultimately lead to a reasonable revival of gold
mining in the South. Examinations would be greatly stimulated by
more disinterested co-operation and reasonable demands of the mine
owners, ultimately to their benefit. It is to be hoped that speculative
investments in the Southern gold mines have had their day, and that
all future operations will be conducted on such a business-like basis as
begets confidence and stabilitv.
NDEX
T
Abandonment of mines, reasons for. 150, 151
Abbeville county, S, C, mines in 77
Adams, W. H., cited 73
Age of ore deposits, Carolina gold belt... 18
Alabama, distribution of mines in 85-90
early discovery of gold in 27
geological map of, referred to. .25
production of gold and silver
in 40, 42
Alabama Geological Survey, publications
referred to 13, 25, 27, 30, 85, 90
Alabama gold belt, description of 25
mines in 85-90
Alamance county, N. C, occurrence of
gold in 45
Alexander county, N, C, occurrence of
gold in 68
Alexander mine, N. C 63
Allen (Lalor) mine, N. C 47, 4S
Allen Furr mine, N. C 60
Allerton-Ream mine, Md. 71
Alta (Idler or Monarch) mine, N. C..37, 69
Amalgamation mills, types of 35
American Cyanide Gold and Silver Recov-
ery Co., referred to 38, 53
American Institute of Mining Engineers,
Transactions of, referred to 9, 10, 14, 24,
31, 32, 35, 39, 62, 71, 102, 106, 129, 139.
American Journal of Science, referred to
27, 28, 73 74
American Philosophical Society, Proceed-
ings of, referred to 27
Ammons-Branch mine, N. C 70
Anna Howe mine, Ala 85, 86
Anna Howe Extension mine, Ala 85, 86
Anson county, N. C, mines in 57
Appalachian (Coggins) mine, N. C 53
Appomattox county, Va., occurrence of
gold in 76
Arbacoochee, Ala., early mention of
ground-sluicing 30
Arbacoochee Hydraulic Company, referred
to 85
Arbacoochee mining district. Ala 85
Argentiferous ores 39, 48-51, 58
Arlington mine, N. C 63
Arminius pyrite mine, Va 14, 73
Arrastra, use of 33
Ashe county, N. C, auriferous copper ores
of 14, 70
Assays, value of 151
Atlas mine, N. C 57, 60
PAGE
Auraria, Ga., early mining population of. 29
Auriferous copper ores.. 14, 18, 45, 46, 48,
51. 70
Auriferous garnets 24
Bailey (Hamilton) mine, N. C 57
Baker mine, N. C 68
Bame mine, N. C 57, 60
Barlow mine, Ga 80
Barnhardt mine, N. C 62
Barnhardt vein, Gold Hill, N. C 58, 59
Barrier mine, N. C . 62
Barringer mine, N. C 32, 56
Bartlett lead-zinc-oxide process 37
Barton county, Ga., occurrence of gold in. 82
Bast mine, Ga 80
Bat-Roost mine, N. C 57
Beason mine, X. C 45
Beaver-Dam mine, N. C 30, 52
Bee-Mountain mine, N. C 68
Bechtler, A. referred to 41
C. referred to 41
C. Jr., referred to 41
Bechtler coinage of gold in North Caro-
lina 41, 42
Becker, Geo. F., cited. .9, 11, 13, 14, 18, 22,
23, 26, 77
Beguelin (Blauvelt) mine (see Haile mine)
126-131
Bell mine, N. C 56
Belzora mine, Va 75, 76
Benham and Helmer, Messrs., referred
to 107
Bennifield mine, Ala 86
Bethesda mine, Md 71
Bethesda Mining Co., referred to 71
Betz mine, Ga SO
Big-Bird mine, Va 75, 76
Biggers (Nugget) mine, N. C 60, 61
Bigley mine, Ga 80
Black mine, N. C 47
Blake crushing system 35. 126
Blake, T. A., referred to 126
Blake, Wm. P., referred- to 24, 31
Blankets, use of 36
Blauvelt (Beguelin) mine (see Haile mine)
126-131
Bloomer, Mr., referred to 60
Blount county, Tenn.. occurrence of gold
in 90
Blue Hill mining district, Ala r>0
Bonner mine. Ala 90
Bonnie-Belle (Washington) mine. N. C....63
_Li
/
156
INDEX.
PAGE
Booker mine, Ya 76
Boston Kennesaw Mining Co., referred to.82
Bowles mine, Va 75
Boylston mine, N. C ..69, 70
Brackettown mines, N. C 69
Bradford jig 36
Brawley mine, N. C 63
Brewer mine, S. C 26, 38, 77, 144-147
Brewer Mining Co., referred to 145
Brewer, ¥m. M., referred to 13, 86
" Brickbat " rock, defined 21
Bright mine, N. C 52
Brindleton (Bunker Hill) mine, N. C 31
Brindletown, N. C, early mining popula-
tion at 29
Bromination process 153
Brown mine, N. C 57
Buckingham county, Va., mines in 76
Buckingham mine, Va 76
Bucyrus Steam Shovel Co., referred to.. 106
Buddies, use of 36
Buffalo mine, N. C 60, 61
Bugbee, Wm., referred to 75
Bullion mine, N. C 57
Bumalo pits (Haile mine) 129, 130, 132
Bumping tables, use of 36
Bunker-Hill (Brindleton) mine, N. C 31
Bunnell-Mountain mine, N. C 52
Burke county, N. C, mines in 68, 69
Burns (Cabin Creek) mine, N. C...38, 56, 57
Busby mine, Va 75
Butt mine, Ga 79
Cabarrus county, N. C, mines in 60-62
Cabin-Creek (Burns) mine, N. C..38, 56, 57
Cabin Creek Mining Co., referred to 57
Cagle mine, N. C 57
Caldwell county, N. C, mines in 68
Calhoun mine, Ga 80
California mine, Ala 89
California (Tucker) mine, N. C 38, 61, 62
Caloric Reduction Company's process 39
Camille (Royal) mine. Ga 38, 82, 83
Campbell Mining and Reduction Co., re-
ferred to 48
Cane Creek gold deposits, Tenn 90
Cane Creek mine, N. C 69
Capps mine, N. C 63-66
Carolina gold belt, description of 15-18
in Georgia. 15, 24, 84, 85
in North Carolina,
15, 45-68
in South Carolina. 15, 77
mines in 45-68, 77, 85
Carolina-Igneous gold belt 13
Carolina-Slate gold belt 13
Carroll county, Ga., mines in 82
Carroll county, Va., occurrence of gold in. 76
Carter mine, N. C 52
Case, Wm. H., referred to 74
Catawba county, N. C, occurrence of gold
in 68
Catawba (Kings Mountain) mine, N. C,
18, 35, 66-68
PAGE
Census Report of United States, referred
to 42
Chambers county, Ala., occurrence of gold
in 90
Chance, H. M., referred to 56
Characteristic deep mines described . 115-147
Characteristic placer mines described.91-115
Charlotte county, Va., occurrence of gold
in 76
Chase-Hill mine pits (Haile mine),
127. 129, 131
Chatham county, N. C, occurrence of gold
in ...45
Chatham mine, N. C 45
Chattahoochee (or Plattsburg) Gold Min-
ing and Milling Company's mines, Ga..79
Chemical processes 37-40
Cherokee county, Ga., mines in 81, 82
Cherokee county, N. C, placer mining in. 70
Cherokee mine, Ga 82
Chestatee Company, referred to. 79. 101, 102
Chestatee mine, Ga 32. 101-106
Chestatee River dredge boats 106, 107
Chester (Latham) mine, Ga 82
Chesterfield county, S. C, mines in 77
Childs, Mr., referred to 78
Chilian mills, use of 33
Chilton county, Ala., occurrence of gold
in 90
Chincapina mine, Ala S9
Chlorination plant, illustrations of... 139-141
Chlorination processes, introduction of.37, 38
Chlorination process at Brewer mine 147
Franklin mine . .125
Haile mine. 137-142
Phoenix mine 62
Reimer mine 119
Royal mine S3
Tucker mine 62
Chulafinnee mining district, Ala S6
Cincinnati Consolidated mine. Ga 32, SI
Citico Creek gold deposits. Tenn 90
Clark mine, N. C 63
Clay county, Ala., mines in S9, 90
Clay county, N. C, mine in 70, 84
Cleburne county, Ala., mines in S5-87
Cleveland county, N. C, petty mining in. 69
Clegg mine, N. C 57
Clingman, T. L., referred to 31
Clopton mine, Ga 38, 82
Clyburne mine, S. C 77
Cobb county, Ga., occurrence of gold in.. 82
Coco Creek gold deposits, Tenn 90
Coggins (Appalachian) mine, N. C 53
Collins mine, Ga SI
Collins mine, Va 75, 76
Columbia county, Ga., mines in S4, 85
Columbia Gold Mining Co., referred to... 75
Columbia mine, Ga S5
Columbia Mining Co., referred to 57
Concentration methods 36
Conrad Hill mine, N. C IS. 39, 51
INDEX.
157
PAGE
Contents, table of 3-5
Cooper Gold Mining Co., referred to 93
Coosa county, Ala., occurrence of gold in. 90
Copper ores, auriferous 14, 18, 45,
46, 48, 51, 70
Cost of chlorination plants 119
chlorinating at Franklin mine.. 125
" " Haile mine . . . .143
diamond drilling at Franklin
mine 124
labor at Arminius pyrite mine... 74
" " Crawford mine 94
" " Franklin mine 125
" Haile mine 143
" " Idaho mine 89
" " Kings Mountain mine.. 67
" " Parker mine 56
" " Pinetucky mine 88
" " Reimer mine 117, 119
labor, general discussion 154
milling at Franklin mine 125
" " Parker mine 55
milling, concentrating, roasting
and chlorinating at Reimer
mine 121
mining at Phoenix mine .62
mining, crushing and tramming
at Franklin mine 125
mining and milling at Brewer
mine 147
mining and milling at Crawford
mine 94
mining and milling in Dahlonega
district 114
mining and milling at Idaho
mine 89
mining and milling at Kings
Mountain mine 67
mining and milling at Lockhart
mine 116
mining and milling at Lucky Joe
mine 86
mining and milling at Slate Hill
mine 74
roasting at Franklin mine 125
" " Haile mine 143
" " Reimer mine 119
supplies at Franklin mine 125
" " Haile mine 143
stamp mill equipments 113, 119
Cox mine, Ga 82
Crandall hydraulic gravel elevator,
32, 102-105
Crandall, W. R., cited 102
Crawford mill 35
Crawford (Ingram) mine, N. C 54, 91-95
Crawford Mining Co., referred to 93
Creighton (Franklin) mine, Ga.81, 82, 121-125
Creighton Mining and Milling Co., refer-
red to 121, 123
Cross, Jno., referred to 83
Cross mine, S. C. (see Haile mine),
127, 129, 130, 131
PAGE
Crowell mine, Stanly county, N. C 56
Crowell mine, Union county, N. C 63
Crown Point mine, Ala 86
Crumpton mine, Ala 86
Crutchfield mine, Ala 85
Culp (Little Fritz) mine, N. C 56
Culpeper county, Va., mines in 72
Culpeper mine, Va 72
Currahee mine, Ga 80
Cyanide process, application of 38, 153
Cyanide process at Brewer mine 147
Cabin Creek (Burns)
mine 38, 57
Franklin mine... 38, 123
Gilmer mines 38
Gold Hill mines.. 38, 60
Jones mine 47
Moratock mine ...38, 54
Reimer mine 121
Russell mine 38, 53
Sawyer mine 38, 47
Dahlonega, Ga., early mining population. 29
Dahlonega method of mining and milling,
general description 32, 107-115
Dahlonega method of mining and milling,
future of 149, 150
Dahlonega method of mining and milling,
at Hedwig mine 114, 115
Dahlonega method of mining and milling,
at Parker mine ., 55
Dahlonega mining district, Ga...80, 107-115
Dahlonega Mint, the, referred to .80
Darlington, Wayne, referred to 61
Davidson county, N. C, mines in 47-51
Davidson Hill mine, N. C 63
Davie county, N. C, occurrence of gold in. 68
Davis chlorination process.... 38
Davis and Tyson Metallurgical Works, re-
ferred to 38
Davis mine, Halifax county, N. C 43
Davis (Dutton or Morris Mt.) mine, Mont-
gomery county, N. C 53
Davis (Ophir) mine, Montgomery county,
N. C 52
Davis mine, Union county, N. C 63
Davis Mountain mine, N. C 47
Dawson county, Ga., mines in 81
Dean (St. George) mine, Ga 79
Decomposition of rocks 11
Deep Flat mine, N. C 52
Deep River mine, N. C 45
Delft mine, N. C 47
Derr mine, N. C. 66
Designolle process 39
De Soto Mining Co., referred to 144
Diabase dikes, influence of on ore-bod-
ies .16, 63, 126
Diamond drilling at Capps mine 64-66
Franklin mine 123
Haile mine 132
Pinetucky mine . . . .SS
Distribution of mines in Alabama 85-90
Georgia 78-85
Maryland 71
v>
158
IXDEX.
PAGE
North Carolina. .43-70
South Carolina.. 76-78
Tennessee 90
Virginia 71-76
Dixon mine, N. C 68
Dorn mine, S. C 77
Douglas county, Ga., occurrence of gold in. 82
Drag-mill, use of 33
Dr. Charles mine, Ga 81
Dredge mining .32, 106, 107
Dry Hollow mine, N. C 52
Duffle mine, N. C 66
Duncan mine, Va 76
Dunn mine, N. C 26, 63
Dunns Mountain mine, N. C 57
Dutch Creek mine, N. C 60
Dutchmans Creek mine, N. C 52
Dutton (Davis or Morris Mt.) mine, X.C..53
Dyne Creek Co., Ala., referred to 87
Eades mine, Va 75, 76
Eagle mine, Va 72
Eames, R., referred to 38, 58, 93
Early concentrating methods 36
Early discoveries of gold in the Southern
states 26, 27
Early discovery of auriferous veins 32
Early milling appliances 33-36
Early mining and metallurgical prac-
tice 29-40
Early mining operations 27-29
Early records of vein mining 32
Earnhardt (Randolph) vein, Gold Hill,
N. C 34, 58, 59
Eastern Carolina gold belt, description of,
14, 15
mines in. .43, 45
Eckels mine, Ala 87
Edgefield county, S. C, mines in 77
Egypt mine, Ga 85
Electrolytic chlorination process 38
Elevators, hydraulic gravel, 32, 98, 99,
102-105
Ellet, Wm. H., cited 31
Ellis mine, Va 72
Elrod mine, Ga 80
Elwood mine, N. C 69
Embrey concentrating machine 36
Emmons, E., cited 27, 34, 5S
Emmons, S. F., cited 14, 71
Engineering Magazine, referred to 10
Engineei'ing and Mining Journal, referred
to 50, 74, S6
Etowah mine, Ga , SI
Eureka mine, N. C 47
Eva Furr mine, N. C 60
Faggart mine, N. C 62
Fair Mining and Milling Co., referred to..SS
Farrar mine, X. C GO
Farrow Mountain mining district, Ala.... 90
Fauquier county, Va., mines in 72
Fentress (North Carolina) mine, N. C..45, 46
Ferris mine, X. C 04, 66 I
Fesperman, F. A. referred to 91 '
Filer and Stowell Co., referred to 109
Findley mine, Ga.., SO, 109
Fish Trap mine, Ga 80
Fisher, Geo., referred to 75
Fisher, Jas., referred to 75
Fisher lode, Va 14, 74
Fisher mine, Va 75
Fisher Hill mine, N. C 45
Flint pit (Haile mine) 129, 130
Floyd county, Va., occurrence of gold
in 71, 76
Fluvanna county, Va., mines in 75, 76
Ford mine, Va 7$
Forsythe county, Ga., mines in 81
Fowler mine, Ga SI
Franklin county, X. C, mines in 43, 45
Franklin (Idaho) mine, Ala 89
Franklin (Creighton) mine, Ga...23, 24, 38,
81, 82, 121-125
Franklin mine, Va 72
Freemilling ores, treatment of 32-36
Freiberg amalgamation barrel 35
Frue Vanner concentrating machine 36
Frye, Mr., referred to 106
Funderburk mine, S. C 77
Furness mine, X C 62
Gangue minerals 18, 24
Gardiner mine, Va 72
Gardner Hill mine, X. C 45, 46
Garnet mine, Ga 80
Garnets, auriferous 24
Garnett and Mosely mine. Va 76
Gaston county, X. C, mines in 66-6S
Gay mine, S. C 77
General conclusions and considerations,
148-154
Genesis of ore deposits, Carolina gold
belt 17, IS
Genesee Gold Mining Co.. referred to.... 53
Geological map of Alabama, referred to.. 25
Geological Survey of Alabama, publica-
tions referred to 13, 25, 27, 30, S5, 90
Geological Survey of Georgia, publications
referred to 13. 7S
Geological Survey of Xorth Carolina, pub-
lications referred to.. 9, 13, 21. 29, 33, 34.
43, 46, 48, 5S
Geological Survey of South Carolina, pub-
lications referred to. .13, 32, 37. 41. 77. 126
Geological Survey of United States, pub-
lications referred to. 11. 13, IS. 22, 23. 24. 26
Geological Survey of Virginia, publica-
tions referred to 13
Geology of the Southern Appalachian gold
belt 11-25
Georgetown Valley, X. C, placer mining.. 70
Georgia, distribution of mines in 7S-S5
early discoveries of gold in. .26. 27
production of gold and silver
in 40. 42
Georgia Geological Survey, publications
referred to 13. 7S
\
INDEX.
159
PAGE
Georgia gold, belt, description of 21-25
mines in 78-85
Georgiana mine, Ga 82
Gibb mine, N. C 62
Gibson, Mr., referred to 32
Gilmer mines, Va 38
Gilmore mine, "Va 75
Glades P. O., Ga., gold and monazite
at 21, 80
Glenbrook Mining Co., referred to 52
Gold belt, the Alabama, description of 25
mines in 85-90
the Carolina, description of. 15-80
in Ga., 15, 24, 84, 85
in N. C...15, 45-68
in S. C 15, 77
mines in 45-68,
77, 85
the Carolina-Igneous 13
the Carolina-Slate 13
the Eastern Carolina, descrip-
tion of 14, 15
the Eastern Carolina, mines
in 43. 45
the Georgia, description of. .21-25
mines in 78-85
the Kings Mountain 13
the South Mountain, descrip-
tion of 18-20
the South Mountain, in N. C. 68-70
in S. C. 77, 78
mines in, 68-70, 77, 78
the Southern Appalachian, de-
scription of 11-25
the Southern Appalachian, di-
visions of 13
the Southern Appalachian, ge-
ology of 11-25
the Virginia, description of. 13, 14
mines in 71-76
Gold belts, minor, in Georgia 24, 25
in North Carolina. .20, 21
Gold Hill, N. C, map showing distribution
of veins 59
Gold Hill, N. C, population of early min-
ing camp 29, 58
Gold Hill mines, N. C 34, 37, 38, 57-60
Gold Hill Mining Co., referred to 58
Gold Knob mine, X. C, 57, 60
Gold milling machinery 33-36
Gold and Silver production, statistics. .40-42
Goldberg mining district, Ala 88, 89
Golden Eagle (Price) mine, Ala 87
Golden Gate mine, S. C 78
Golden Valley ore zone 20
Golden Valley placer mines, X. C 69
Goldville, Ala., population of early mining .
camp 29
Goldville mining district, Ala 90
Goochland county, Va., mines in 75, 76
Goodman mine, X. C 57
Goodwin mine, Va 73
Grampusville mine, X. C 56
PAGE
Granville county, X. C, mines in 45
Gravel elevators, hydraulic, 32, 98, 99,
102-105
Grayson county, Va., occurrence of gold
in 76
Greenville county, S. C, mines in.... 77, 78
Greenwood mine, Va 73
Gregory Hill mining district, Ala 90
Grindstone Hill mine, Va 73
Ground-sluicing, early mention of 30
Guilford county, N. C, mines in 45, 46
Gum mine, Ala 90
Gwinnett county, Ga., mines in 81
Habersham county, Ga., occurrence of
gold in 78
Haile Gold Mining Co., referred to 125
Haile mine, S. C 16, 17, 35, 38, 39, 76,
77, 125-143
Haile pit (Haile mine) 129, 130
Haithcock mine, X. C 54
Hale mine, S. C 78
Halifax county, X. C, mines in 43
Halifax county, Va., occurrence of gold in.76
Hall, F. W., referred to Ill
Hall county, Ga., mines in 80
Hall stamp-mill 35, 110-113
Hamilton, Benj., referred to 31
Hamilton (Bailey) mine, X. C 57
Hammett mine, S. C 78
Hancock placer mines, X. C 69
Hand-Barlow Co., referred to 79
Hand and Barlow ditch, Dahlonega 108
Hand and Barlow United Gold Mines and
Hydraulic Works of Georgia, referred
to
.109
Hand mine, Ga 80, 109
Hand-mortars, use of 33
Hanna, Geo. B., referred to. 10, 13, 26, 41, 42
Haralson county, Ga., mines in 82, 83
Harland and Beard mine, X. C 45
Harris mine, Va 14, 74
Harrison (Sawyer) mine, Md 71
Harrison mine, X. C 57
Hartman mine, X. C 57
Hearne mine, N. C 54
Hedwig mine, Ga 23, SO, 114, 115
Hemby mine, X. C 63
Henderson county, X. C, mine in 69, 70
Henderson mine, X. C 64
Hendy lift (gravel elevator) 32, 98, 99
Herring (Laughlin) mine, X. C 47
Hicks-Wise mine. Ala S6
Higginbotham mine, Ala S6
Hill mine, X. C 57
Historical notes 26-40, 10S
Hobbs mine, Ala 89
Hodges Hill (Hodgins) mine, X. C 45
Hodgins (Hodges Hill) mine, X. C 45
Hog Mountain mining district, Ala 90
Hogan, J., referred to 26
Holland, Dr., referred to 36
Holloway miue, X. C 45
Holtskauser mine, X. C 57
A '
t
160
IXDEX.
PAGE
Honey cut vein, Gold Hill. N. C 58, 59
Hoover Hill mine, N. C 46, 47
Horner mine, Ga 80
Horns Peak mine, Ala 89, 90
Howell mine, N. C 63, 64
Howes, Amos, referred to 58
Howie mine, N. C 63
Howland mill 35
Huddleston mine, Md 71
Hughes mine, Va 75, 76
Hunt mine, Ga 84
Hunt and Douglas process 39, 51
Huntington mill 35, 36
Huntsville ore zone 19
Huntsville placer mines, X. C 69
Hydraulic gravel elevators, 32, 98. 99,
102-105
Hydraulic mining methods .30-32
Hydraulic mining at the Chestatee mine
101-106
Crawford mine
92-95
in the Dahlonega dis-
trict 108-110
at the Hedwig mine.. 114
Mills mine.. 96-101
Parker mine. 54, 55
Portis mine 45
Sam Christian
mine 52
Yon ah mine. . . .79
Hydraulic pumping engine at the Findley
mine 109
Idaho (Franklin) mine, Ala 89
Idaho mining district, Ala 88, 89
Idler (Alta or Monarch) mine, X. C..37. 69
Idler-Mine ore zone 20
Illustrations, list of 6
Influence of diabase dikes on ore-bodies,
16. 63, 126
Ingram (Crawford) mine, X. C....54, 91-95
Irma mine, Md 71
Isenhour mine, X. C. . . , 60
Island Creek mine, X C 52
Ivy mine, Ga SO
Jack Brown mine, Ga 84
Jacks Hill mine, X. C 45, 46
Jackson county, X. C, placer mining in.. 70
Jacquish, Mr., referred to 106
James Moore mine, Ala 86
Jamestown (Vein Mountain) mine,
X. C 31, 69
Jarrett mine, Ga 78, 79
Jefferson, Thos., cited 26
Jesse Cox mine, X. C 57
Joel Reed mine, X. C 60
Johnston mine, Va 73
Jones (Keystone) mine, X. C 47
Josephine mine, Ga 80
Joshua Hendy Machine Works, referred
to 98
Kearney mine, X. C 43
Kemp Mountain mining district. Ala 87
Keystone (Jones) mine. X. C 47
Kiggins mine, Va 73
Kin Mori mine, Ga SI
King mine, Ala ■ SO
Kings Mountain gold belt 13
Kings Mountain (Catawba) mine. X. C,
18, 35, 66. 67. 68
Kirkley mine, S. C 77
Knight, Mr., referred to 87
Knott mine, S. C 78
Knuckelsville, Ga., early mining popula-
tion of 29
Lalor (Allen) mine, X C 47. 48
Lancaster county, S. C, mines in 77
Latham (Chester) mine, Ga 82
Laughlin (Herring) mine, X. C 47
Laurel mine, Ala S9
Lawrence mine, Ga 80
Leach mine, S. C 77
Lee mine, Ala 86
Lehmann, G. TV, cited 50
Leopold mine, Va 72
Letter of Transmittal 8
Lewis mine, X. C 63
Lidner, P. G., referred to 38. 147
Lieber, O. M., cited 13. 32. 37. 77. 126
Lightf oot mine, Va 76
Lincoln county, Ga., mines in S4. 85
Lincoln county, X. C, occurrence of gold
in 68
Lindsay mine, X. C 45. 46
List of illustrations 6
Little mine, Ga 81
Little Fritz (Culp) mine, X. C 56
Locke, A. G., referred to 106
Lockhart mine, Ga 21, 24, SO, 115. 116
Lof tin mine, X. C 47
London mine, Va 76
Long mine, X. C 63
Long Creek mine, X C 66. 67
Longstreet placer mine, Ga 79
Loud mine, Ga . . . . < 79
Louisa county, Va., gold mines in... 73, 74
pyrite mines ...73. 74
Louisa mine, Va 74
Lowder mine, X. C 54
Luce mine, Va 14. 74
Lucky Joe mine, Ala S6
Lumpkin county, Ga., mines in SO, SI
Lumsden mine, Ga 7S
Macon county, X. G* occurrence of gold
in TO
Magazine (or Parker) Branch placer-mine.
x c 101
Magruder mine, Ga 85
Mammoth mine, Ga SO
Mann mine, X. C 43
Mann-Arrington mine, X. C 15. 43. 45
Map of Xorth Carolina, showing distribu-
tion of gold deposits 44
Map of Gold Hill mining district, showing
distribution of veins 59
Map, showing location of mines and plant.
Haile mine 127
Map, showing plan of Capps mine 65
INDEX.
161
PAGE
Marks mine, Va 75, 76
Marion Steam Shovel Co., referred to... 107
Marion-White mine, Ala 86
Marshall mine, Va 72
Martin Mining Co.'s mine, Ga 79
Mary-Henry (Murray) mine, Ga 80
Maryland, distribution of gold mines in. .71
early discoveries of gold in. . . .27
production of gold and silver
in 40, 42
Maryland mine, Md. 71
Matte-smelting 39
McCullough (North State) mine, N. G,
39, 45 ,46
McDowell county, N. C, mines in... 68, 69
McDuffie county, Ga., mines in 84, 85
McGinn mine, N. C 36, 63, 66
McGuire mine, Ga 81
Mclnnis mine, S. G 77
McLean mine, N. C 66
McMackin vein, Gold Hill, N. C 58, 59
McMinn county, Tenn., occurrence of gold
in 90
Mears chlorination process 37, 62
Mecklenburg county, N. C, mines in.. 63-66
Mecklenburg Iron Works, referred to.... 66.
119, 120, 124, 135
stamp mill.. . .35,
119, 120
test plant. 119, 151
Meech mill 35
Melville mine, Va 73
Mercer mine, Ga 79
Meriweather county, Ga., mines in 83
Merrick mine, Ga 80
Middlebrook mine, Ala 86
Miller mine, Ala 86
Miller mine, N. G 45
Milling machinery 33-36
Milling practice at the Bonnie Belle mine, 63
Brewer mine .... 147
in the Dahlonega district,
Ga 110-114
at the Franklin mine . .124
Haile mine. ..135-137
Hedwig mine. 114-115
Idaho mine 89
Kings Mountain
mine 67
Lockhart mine. . .116
Parker mine 55
Iteimer mine 119
Millis Hill mine, N. G 45
Mills' (Statistics of South Carolina), cited. 26
Mills, J. C, referred to 77
Mills property, N. C, placer mines 69, 95-101
Mineral Farm mine, Ga 82
Mineral Hill mine, Ga 82
Mines in Alabama 85-90
Georgia 78-85
Maryland 71
North Carolina 43-70
South Carolina 76-78
11
PAGE
Mines in Tennessee 90
Virginia 71-76
Mining Magazine, referred to 40
Mining and Statistic Magazine, referred
to 31. 32
Mining, milling, and metallurgical treat-
ment of sulphuret ores at characteristic-
mines 117-147
Mining practice at characteristic placer
and free milling mines 91-115
Mining practice at the Chestatee mine,
102-106
Crawford mine 92-95
in the Dahlonega dis-
trict 107-110
at the Franklin mine,
123, 124
Haile mine. .132-135
Lockhart mine.
115, 116
Mills mine 96-100
Minor gold belts in Georgia 24, 25
North Carolina... 20, 21
Mitchell, Elisha, cited 33
Mitchell mine, Va 73
Monarch (Alta or Idler) mine, N. C..37, 69
Monazite, occurrence of 19, 21, 97
Monroe county, Tenn., occurrence of gold
in 90
Monroe mine, Va 72
Monroe slates, described 1G
Montgomery county, Md., mines in 71
Montgomery county, N. C, mines in.. 51-54
Montgomery county, Va., occurrence of
gold in 76
Montgomery mine, Md 71
Montgomery mine, N. C 60
Moore county, N. C, mines in 56, 57
Moore mine, N. C 63
Moore Girls' mine, Ga 78
Moratock mine, N. C 38, 53, 54
Morganton ore zone 19
Morris Mountain (Davis or Dutton) mine,
N. C 53
Morrow mine, Va 76
Morton mine, Va 76
Moss, Jno., referred to 75
Moss mine, Va 75
Moss-Back mine, Ala 86
Murray (Mary-Henry) mine, Ga SO
Nacoochee Hills Gold Mining Co.'s mines,
Ga 70
Nacoochee Valley mining district, Ga.TS. 79
Nancy Brown mine, Ga S4
Nash county, N. C, mines in 43
Nason, F. L., referred to 74
Negus mine, N. C . 57
New Discovery mine, X. C 39, 57
New Gold Hill Co., referred to 58
New London Estates Co.. L't'd., referred
to •• 54
Nick-Arrington mine. N. C 43
Nininger, Mr., referred to 40
-
162
INDEX.
Nitze, H. B. C
Nobles process
PAGE
referred to 13
35
North Carolina, distribution of mines in,
43-70
early discovery of gold in. 26
production of gold and sil-
ver in 40, 42
North Carolina Geological Survey, publica-
tions referred to. .9, 13, 21, 29, 33, 34, 43,
46, 48, 58
North Carolina (Fentress) mine, N. C. .45, 46
North Carolina Smelting Co., referred to. 49
North State (McCullough) mine... 39, 45, 46
Notes on Virginia (Jefferson), cited.. 26
Nuggett (Biggers) mine, N C 60, 61
Old Field mine, Ga 84
Oliver mine, N. C 26, 66
Olmstead, Prof., cited 28
Ophir (Davis) mine, N. C 52
Orange county, N. C, occurrence of gold
in 45
Orange county, Va., mines in 73
Orange Grove mine, Va 73
Ore concentration 36
Ore zones of South Mt. gold belt 19, 20
Page mine, Va 75
Palmetto mine, S. C 77
Parish mine, N. C 47
Parker (or Magazine) Branch placer mine,
Burke county, N. C 101
Parker mine, Cherokee county, N. C....26
Parker mine, Stanly county, N. C 54
Parks mine, Ga 81
Parks mine, N. C 63
Parson mill 35
Patrick county, Va., occurrence of gold in.76
Paulding county, Ga., mines in 82
Pax Hill mine, N. C 68
Payne mine, Va 75
Pear Tree Hill mine, N. C 52
Person county, N. C, occurrence of gold
in 45
Phelps process 39
Phifer mine, N. C 63
Phillips, W. B., cited 13, 27, 62, 90, 139
Phoenix mine, N. C 37, 60-62
Pickens county, S. C, occurrence of gold
in
77
Piedmont mine, Ga 81
Pilot mountain, N. C, hydraulic mining
at 32
Pilot Mountain ore zone 19, 20
Pine Mountain mine, Ga 82
Pinetucky mine, Ala 87, 88
Pioneer Mills mine, N. C 61, 62
Placer mines, described 91-115
Placer mining, possibilities of discussed,
148, 149
Plattner chlorination process 38, 62
Plattsburg (or Chattahoochee) Gold Min-
ing and Milling Co.'s mines, Ga 79
Polk county, N. C, petty mining in 69
Polk county, Tenn., occurrence of gold in. 90
PAGE
Portis mine, N. C 4M. 45
Potosi mine, Ga 80
Powhatan Land and Mining Co.. referred
to 72
Preacher mine, Ga 80
! Preface 9, 10
; Price (Golden Eagle) mine, Ala 87
j Prince Edward county, Va., occurrence of
gold in 76
Pritchard mine, Ala 86
Proceedings of American Philosophical So-
ciety, referred to 27
I Pullian mine, Va 73
Pyrite mines of Louisa county, Va. . . .73. 74
! Quaker City mine, N. C ' 60. 62
j Rabun county, Ga., mines in 78
| Ralston mine, Ga 80
| Randleman mine, N. C 57
Randolph county, Ala., mines in 87-89
! Randolph county, N. C, mines in 46-47
I Randolph (Earnhardt) vein, Gold Hill. N.
C 34. 58. 59
! Rappahannock Gold Mining Co., referred
to 72
I Rattlesnake mine, Va 72
I Ray mine, N. C 64
Red Hill mine pit (Haile mine). 127. 129, 132
| Reed mine, N. C 60. 61
I Reimer mine, N C 36, 38, 57, 117-121
Reynolds mine, N. C 52
Reynolds vein. Ga 32
Rhyne mine, N. C 66
Richardville mine, Va 72
Riddle mine, Ala. 90
Riggon Hill mine, N. C 53
Ringel, C, referred to 37
Roasting processes 36, 37
Roasting process at Franklin mine.. 124. 125
Haile mine 137-139
Reimer mine 119
Robinson mine, N. C 66
Rock-decomposition 11
Rockers, descriptions of 30, 94. 95
Rocky River mine, N. C 60, 61
Rogers, ^Ym. B., referred to 13
Rose, T. K., referred to 142
Roseman mine, N. C 5 1
Rowan county, N. C, mines in 57-60
Roy Stone method of dredging and gravel-
elevating - 32, 106
Royal (Camille) mine 3S, S2, 83
Rudisil mine, N. C 63, 64
Russell mine, N. C 17, 3S, 52. 53
Rutherford county, N. G, mines in. .68. 69
Safford's Geology of Tennessee, referred
to 27
Salisbury Supply Co., test mill lol
Sam Beattie mine, N. C 66
Sam Christian Company, referred to 52
Sam Christian mine, N. C 52
Sand-pump, used as gravel elevator 102
Saprolite, definition of
Saunders mine, N. C
,53
INDEX.
163
PAGE
Sawnee Mountain mine, Ga 81
Sawyer (Harrison) mine, Mel 71
Sawyer mine. N. 0 38, 47
Seott Hill mine, N. C 68
Settles mine, Ga 81
Shelby mine, Ga 81
Shields mine, N. C 57
Silliman, Prof. B., cited 20, 75
Siloam mine. Ga 80
Silver ores 30, 48-51, 58
Silver and Gold production, statistics of,
40-42
Silver Creek placer mines, N. C 07
Silver Hill (Washington) mine, N. C,
18, 37, 30, 40, 48, 49
Silver Valley mine, N. C...18, 30, 40, 40-51
Simmons mine, Ga 81
Simpson mine, N. C 64
Singleton mine, Ga 21, 23, 35, 80
Sixes mine, Ga 82
Skip used at Haile mine 134, 135
Slack mine, N. C 47
Slate Hill mine, Va 14, 74
Sluice-box, descriptions of.... 30, 03, 04, 100
Smart mine, N. 0 63
Smelting processes ..30, 40, 50, 51, 153, 154
Smelting process at the Conrad Hill mine. 51
Silver Hill mine... 30, 40
Silver Valley mine. 40, 50
Smith, Mrs. J. B., referred to 85
Smith mine, Ga 78
Smith (Welborn) mine, Davidson county,
N. C 51
Smith mine, Gaston county, N. C 66
Smith and Palmer mine, N. C 63, 64
South Carolina, distribution of mines in,
76-7S
early discovery of gold.. 26
production of gold and
silver in ... .40, 42
South Carolina Geological Survey, publica-
tions referred to 13, 32, 37, 41, 77, 126
South Carolina State Board of Agricul-
ture, publication referred to 76
South Mountain gold belt, elescription
of 18, 20
in N. C 68-70
in S. C 77-78
ore zones of 10, 20
mines in, 68, 70, 77, 78
Southern Appalachian gold belt, descrip-
tion of 11-25
divisions of 13
geology of, 11-25
Southern Belle mine, N. C 57
Southern States Exploration and Financial
Syndicate, L't'd., referreel to 82
Spanish Oak Gap mine, N. C 52
Spartanburg county, S. C, mines in.. 77, 78
Spence roasting furnace 130
Spillsbury, E. G., referred to 30, 120
Spottsylvania county, Va., mines in. .72, 73
PAGE
St. Catherine mine, >'. C 63, 64
St. George (Dean) mine. Ga 70
Stafforel county, Va., mines in 72
Stamp-mill, history of 33, 35
the Hall pattern elescribed,
110-113
the Mecklenburg Iron Works
pattern elescribed ....110, 120
Standard vein. Gold Hill, N. C 58
Stanley mine, Ga 80
Stanly county, N. C, mines in 54-56
Statistics of gold and silver production. 40-42
Statistics of South Carolina (Mills), cited. 26
Steel mine, N. C 53
Stephen Wilson mine, N. C 63
Stewart mine, N. Co 63
Stockton, Commodore, referred to.... 30, 145
Story mine, Ala 00
Strickland mine, Ga 82
Stringer-lead, defined 23
Surface Hill mine, N. C 64
Sutherland mine, Ala 86, 87
Swain county, N. C, placer mining in... 70
Swedish chlorination process 153
Table of contents 3-5
Tables showing production of gold and
silver 40-42
Tagus mine, Va 75
Talc-schist, incorrect use of term 15
Talladega county, Ala., mines in 00
Tallapoosa county, Ala., occurrence of gold
in 00
Tanyard placer, Brewer mine .145
Tatham mine, Ga 85
Taylor mine, N. C 43
Taylor and Trotter mine, N. C 63
Tellurium, occurrence of in ores, 18, 24, 52, 67
Tellurium mine, Va 32, 35, 75
Tennessee, distribution of mines in 00
early discovery of gold in.... 27
production of gold and silver
in 40, 42
Terrell mine, Ala. . . , 00
Thies, A, referred to. 10, 37, 61, 83, 125, 120,
130
Thies chlorination process 37, 153
Thomas mine, N. C 43
Thompson mine, Ga 22, 70
Thompson mine, S. C. 78
Thomson mine, S. C 77
Thurston, Scott, referred to 7.'.
Tiger river placer mines, S. C 7S
Tinder Flats placer mine, Va 20, 74
Tom's Creek mine, N. C 52
Tonton mine, Ga 70
Towne county, Ga., mines in S4
Transactions of American Institute Min-
ing Engineers, referred to 0, 10, 14, 24
31, 32, 35, 30, 62, 71, 102, 106, 120, 130
Trautman vein, Gold Hill, N. C 58, 50
Treatment of freemilling ores.:32-36, 110-116
Treatment of sulphuret ores.. 36-40, 117-147
Tredinick mine, X. C 64
164
INDEX.
• i
PAGE
Triumph concentrating machine 36
Tucker (California) mine, N. C...38, 61, 62
Tuomey, M., cited 30, 77
Turkey Heaven mining' district, Ala.. 86, 87
Turkey Hill mine, Ga 80
Twin mine, N. C 45. 46
Uharie mine, N. C 47
Ulrich mines, Ala 90
Union county, N. C, mines in 62, 63
Union county, S. C, mines in 77
United States assay offices, statistics
from 40-42
United States census report, referred to.. 42
United States Geological Survey, publica-
tions referred to. 11, 13, 18, 22. 23, 24, 26
United States Mining Co., report of,
cited 33, 72
United States mint bureau, statistics
from 40-42
United States mint, reports, referred to,
26, 40-42
Valdor mine, Ala 85
Valley river, N. C, placer mines 70
Van Dyke, Dr. M. H., referred to 31
Vaucluse mine, Va 32. 34, 36, 30, 73
Veins, early discovery of 32
Vein mining, early records of 32
possibilities of. discussed,
150-154
Vein Mountain (Jamestown) mine, N. C. . 31, 60
Villa Rica mining district, Ga 82
Virginia, distribution of mines in 71-76
early discovery of gold in 26
production of gold and silver
in 40, 42
Virginia gold belt, description of 13, 14
mines in 71-76
Virginia, Notes on (Jefferson), cited 26
Virginias, the geology of the, referred to. 13
Volcanic rocks of the Carolina gold belt.. 16
Walker-Carter roasting furnace 39
Wallace mine, S. C 77
Walters and Gardner mine, Va 76
Walton mine, Va 74
Walton Mining Co., report of. referred to. 29
Warne mine, N. C 70, 84
Warren county, Ga., mines in 84, 85
Warren county, N. C, mines in 43
Warren mine, Ga 85
Warren Hill mine, Va 14, 74
Washington (Bonnie Belle) mine. X. C 63
Washington (Silver Hill) mine, X. C. .48, 49
Watauga county, X. C, auriferous galena
ores 70
PAGE
Water-power, application of to mining. . .154
at the Chestatee mine 101
Crawford mine. .92. 93
Hedwig mine 115
Kin Mori mine 81
Loud mine 79
Mills mines, 95-98, 101
Old Field mine 84
Parker mine 55
Sam Christian mine 52
Wolfe Creek mines. 78
Yonah mine 79
Water-supply of the Dahlonega dis-
trict 108, 109
South Mountain district 95
Welborn (Smith) mine, N. C 51
Welborn Hill mine, Ga 84
West mine, S. C 77
West Springs mine, S. C 78
Whatley, E. T.. referred to 70
White county, Ga., mines in .78, 79
Whitehall mine. Va 73
Widenhouse mine, N. C 60
Wilkes, Jno., referred to 10. 119
Wilkes county, Ga., mines in 84, 85
Wilkes county. N. C, auriferous galena
ores in 70
Wilkes mine. Ga S3
Wilkinson mine. Ga 82
Wilkinson mine, X C 31
Williams mine. Ga 85
Williams mine. S. C 77
Wilson mine, S. C 77
Wilson-Kindley mine, N. C 47
Wimpy, A. G.. referred to 29
Winningham mine, N. C 47
Winslow mine, X C 47
Wiswell mill 35
Witheroods, Jno., referred to 26
Wolfe and Tiger Mining Co.. referred to..7S
Wolfe Creek placer mines, S. C 7S
Woodward mine. Ga 80
Worley mine, Ga 82
Worth mine, X. C. 52
Wycoff mine, Va 72
Yadkin Chlorination Works, referred to. 117
Yadkin county. X. C. mines in 6S
Yadkin mine, X. C 57
Yonah Land and Mining Co., mines. Ga..
79. 150
Yonah Peak, Ga.. granite at 21
York county. S. C. mines in 77
Yorkville mines. Ga S2
i
164
INDEX.
' k
Triumph concentrating machine 36
Tucker (California) mine, N. C...38. 61, 62
Tuomey, M., cited 30, 77
Turkey Heaven mining district, Ala.. 86, 87
Turkey Hill mine, Ga 80
Twin mine, N. C 45. 46
Uharie mine, N. C 47
Ulrich mines, Ala 90
Union county, N. C, mines in 62, 63
Union county, S. C, mines in 77
United States assay offices, statistics
from 40-42
United States census report, referred to.. 42
United States Geological Survey, publica-
tions referred to. 11, 13, 18, 22. 23, 24, 26
United States Mining Co., report of,
cited 33, 72
United States mint bureau, statistics
from 40-42
United States mint, reports, referred to,
26, 40-42
Valdor mine, Ala 85
Valley river, N. C, placer mines 70
Van Dyke, Dr. M. H., referred to 31
Vaucluse mine, Va 32, 34, 36, 39, 73
Veins, early discovery of 32
Vein mining, early records of 32
possibilities of, discussed,
150-154
Vein Mountain (Jamestown) mine, N. C. . 31, 69
Villa Rica mining district, Ga 82
Virginia, distribution of mines in 71-76
early discovery of gold in 26
production of gold and silver
in 40, 42
Virginia gold belt, description of 13, 14
mines in 71-76
Virginia, Notes on (Jefferson), cited 26
Virginias, the geology of the, referred to. 13
Volcanic rocks of the Carolina gold belt.. 16
Walker-Carter roasting furnace 39
Wallace mine, S. C 77
Walters and Gardner mine, Va 76
Walton mine, Va 74
Walton Mining Co., report of, referred to. 29
Warne mine, N. C 70, 84
AVarren county, Ga., mines in 84, 85
Warren county, N. C, mines in 43
Warren mine, Ga , 85
Warren Hill mine, Va 14, 74
Washington (Bonnie Belle) mine. N. C....63
Washington (Silver Hill) mine, N. C. .48, 49
Watauga county, N. C, auriferous galena
ores 70
PAGE
Water-power, application of to mining. ..154
at the Chestatee mine.... 101
Crawford mine. .92, 93
Hedwig mine 115
Kin Mori mine 81
Loud mine 79
Mills mines, 95-98, 101
Old Field mine 84
Parker mine 55
Sam Christian mine 52
Wolfe Creek mines. 78
Yonah mine 79
Water-supply of the Dahlonega dis-
trict 108, 109
South Mountain district. .. .95
Welborn (Smith) mine, N. C 51
Welborn Hill mine. Ga 84
West mine, S. C 77
West Springs mine, S. C 78
Whatley, E. T.. referred to 79
White county, Ga., mines in '. . .78, 79
Whitehall mine. Va 73
Widenhouse mine. N. C 60
Wilkes, Jno., referred to 10. 119
Wilkes county, Ga., mines in S4, 85
Wilkes county. N. C, auriferous galena
ores in 70
Wilkes mine. Ga 83
Wilkinson mine. Ga 82
Wilkinson mine, N. C 31
Williams mine, Ga 85
Williams mine. S. C 77
Wilson mine, S. C 77
Wilson-Kindley mine, N. C 47
Wimpy. A. G., referred to 29
Winningham mine, N. C 47
Winslow mine, X. C 47
Wiswell mill 35
Witheroods, Jno., referred to 26
Wolfe and Tiger Mining Co., referred to..7S
Wolfe Creek placer mines, S. C 7S
Woodward mine. Ga SO
Worley mine, Ga S2
Worth mine, N. C . = 52
Wycoff mine. Va 72
Yadkin Chlorination Works, referred to. 117
Yadkin county. X. C. mines in 68
Yadkin mine, N, C 57
Yonah Land and Mining Co., mines. Ga..
79. 150
Yonah Peak. Ga.. granite at 21
York county, S. C. mines in 77
Yorkville mines. Ga S2
K3£ .! km
BULLETIN 11 PLATE 1
8T30'
fc IW'
>v
■ ^ V ^*-4&atl
Yir^L^
NORTH CAROLINA GEOLOGICAL SURVEY
J -A. Holmes, State Geologist
GEOLOGIC SKETCH MAP
OF
ri
estern North Carolina
Showing Corundum Localities and the
distribution of Peridoti tes and Related Rocks.
BY
J.Volney Lewis .
1895.
Scale
Boundaries of the Ocoee formation have been supplied by
Mr. Arthur Keith of the United States Geological Survey.
\
NORTH CAROLINA GEOLOGICAL SURVEY,
J. A. HOLMES, STATE GEOLOGIST.
BULLETIN No. 11.
CORUNDUM AND THE BASIC MAGNESIAN
ROCKS OF WESTERN NORTH
CAROLINA.
BY
JOSEPH VOIvNEY LEWIS,
Assistant Geologist.
MAP CORRECTIONS.
Through some misunderstanding several small errors have been made
in the geological boundaries on the western portion of this map, chiefly in
Unicoi, Cocke and Monroe counties, Tennessee, and in Madison and
Mitchell counties in North Carolina. The errors were discovered too
late to be corrected in this edition. Later work lias also shown that the
Ocoee rocks should be made to extend across the area left uncolored in
Cherokee county (N. C), and Polk county (Tenn.), and that the uncolored
area in Wilkes, Alleghany and Ashe counties should be colored for
"gneisses and granite. " All needed corrections will be made in a future
edition of this map, which it is expected will be published at an early date.
C\
/
*rrp.
• i
CONTENTS.
PAGE.
Letter of Transmittal 7
1. Introduction 9
2. Geologic Sketch of the Corundum Region 11
3. The Peridotites and Associated Massive Rocks 15
(1.) The Peridotites .' 15
a. Dunite 17
b. Harzburgite 23
c. Amphibole-picrite „ 23
d. Forellenstein 24
(2.) The Pyroxenites 25
a. Enstatite rock 25
b. Websterite 27
(3.) Ainphibolites j 28
4. Associated Secondary and Schistose Rocks 30
(1.) Massive 30
a. Serpentine 30
(2.) Schistose 32
a. Talc schist, Soapstone 32
b. Chlorite schist 33
5. Distribution of the Peridotites and Associated Rocks 33
(1.) In the Appalachian belt 33
(2.) In North Carolina 34
a. Clay county . 35
b. Macon county 36
c. Jackson county. 37
d. Transylvania county 39
e. Haywood county 40
/. Buncombe county 40
g. Madison county 41
h. Yancey county 43
i. Mitchell county 44
j. Watauga county 45
7c. Ashe county 46
I. Alleghany county 47
6. Corundum 48
(1.) Character and Varieties 48
(2.) Uses of Corundum 51
(3.) North Carolina Corundum = 51
(4.) Modes of Occurrence of Corundum 54
a. Associated with peridotite. 55
b. In chlorite schist 57
c. In amphibolite 58
d. In dunite 00
e. In gneiss 01
/. In gravel deposits 02
M
CONTENTS.
7.
8.
PAOE.
(5.) Distribution of corundum 63
a. In the Appalachian belt 63
Alabama 64
Georgia 64
South Carolina 64
North Carolina 64
Virginia 65
Maryland 65
Pennsylvania 65
New Jersey 65
New York 66
Connecticut 66
Massachusetts 66
b. In North Carolina 67
Clay county 67
Macon county 69
Jackson county 70
Transylvania county 72
Haywood county 73
Buncombe county 73
Madison county 74
Yancey county 75
Mitchell county 75
Iredell and Alexander counties 76
Burke and Cleveland counties 77
Gaston county 77
Guilford county 77
Other localities 78
(6.) Methods of Prospecting for Corundum 78
(7.) Mining and Cleaning methods 81
Historical Sketch of Corundum Mining- in America 86
(1.) Discoveries and early Developments 87
(2.) North Carolina Corundum mines 89
a. The Behr mine, Clay county 91
b. The Buck creek (Cullakanee) mine, Clay county 91
c. The Corundum Hill (Cullasaja) mine, Macon county 92
d. The Sapphire (Hogback) mine, Jackson county 94
e. The Carter mine, Madison county 94
/. The Acme mine, Sfatesville, Iredell county 95
Other Economic Minerals of the Corundum Belt 96
(1.) Chromite, or chromic iron 96
(2.) Asbestos 96
(3.) Nickel-bearing minerals. 97
(4.) Serpenl ine 97
Literature on the Corundum Belt 99
Index 103
\
ILLUSTRATIONS,
Plate I. Geologic sketch map of western North Carolina Frontispiece.
II. Sketch map of the Appalachian crystalline belt 32
III. Map of the Buck creek peridotite area, Clay county.. 34
IV. Map of Corundum Hill, Macon county 36
V. Map of the Webster peridotite area, Jackson county 38
VI. Photomicrographs of thin sections of dunite 102
FIGURE 1. Corundum crystal, showing rhombohedral parting 49
2. Corundum crystal, showing basal parting 49
3. Corundum crystal from Egypt mine, Yancey county 49
4. Corundum-bearing zone in amphibolite, Iredell county 59
5. Corundum crystal in dunite, Egypt mine, Yancey county.. 60
6. Diagram of corundum-bearing zone, Corundum Hill 93
7. Corundum crystal from Ivy river, Madison county 74
8. Corundum wrapped iu margarite, Iredell county , 76-.
/
LETTEK OF TRANSMITTAL.
Raleigh, N. C, December 1st, 1895.
To His Excellency Hon. Elias Carr,
Governor of North Carolina.
Sir: — I beg to submit for publication as Bulletin 11 of the
Geological Survey, a preliminary report on Corundum and the
associated basic Magnesian Rocks in North Carolina, by Mr. J. Y.
Lewis. The larger part of the corundum now produced in the
United States is mined in North Carolina, and the increasing
demand for information on this subject has led to the preparation
of this paper. It is hoped that a more elaborate final report on
the subject can be prepared by the close of another year.
With great respect, I have the honor to be, sir,
Yours obediently,
J. A. Holmes,
State Geologist.
CORUNDUM AND THE BASIC MAGNESIAN
ROCKS IN WESTERN NORTH
CAROLINA.
BY
J. VOLNEY LEWIS.
■
1
CORUNDUM AND THE BASIC MAGNESIAN ROCKS IN
WESTERN NORTH CAROLINA.
By J. Volney Lewis.
i. INTRODUCTION.
The present incomplete report is issued for the purpose of pre-
senting the field results obtained chiefly during the summer months
of 1893 and 1894.
To the fact that it is mainly a report of field observations is due,
to a great extent, its incompleteness; and I would urge this con-
sideration as an apology for certain vagaries of mineralogic termi-
nology in the following pages, and for many unsatisfactory points
in geologic and petrographic descriptions. As far as possible, I
have confined myself to a simple presentation of facts thus far
determined, and the more theoretical discussions have been
avoided.
In the beginning of the field season of 1893, a rapid reconnais-
sance of the region under consideration was made with the late Dr.
George H. Williams, of Johns Hopkins University ; and a portion
of the laboratory work and the field studies for both this and the
succeeding seasons were prosecuted, to a great extent, under his
guidance and general supervision. Specimens were collected from
all portions of the region, and by the courtesy and cooperation of
the Director of the United States Geological Survey, I have
begun the microscopic study of this material in the Survey laborato-
ries, at Washington. A more thorough report on the corundum-
bearing rocks, embodying the results of this work, will be pub-
lished as soon as practicable.
One acquainted with the methods and aims of geology, or of any
natural science, needs no argument to point oat the necessity of
10
CORUNDUM AND BASIC MAGNESIAN ROCKS.
thorough detailed work for the understanding of any problem in
Nature, whether of immediate economic importance or only of
scientific interest. Thus far all that is known of the extent and
value of our corundum deposits has been derived from experience ;
that is to say, from actual prospecting and mining. Studies of
considerable iuterestand value in the corundum regions have been
made by Chatard, Julien, Shepard, Genth and others, but these
have been confined chiefly to local occurrences and special problems,
and no attempt has been made to cover the whole field ; conse-
quently, the various theories that have been advanced in regard to
the origin of corundum and its associated rocks have left entirely
out of consideration much evidence which only a careful survey of
the whole area could furnish.
I can scarcely hope, by the work in hand, to furnish a final or
even a very satisfactory answer to the question of origin ; for
such problems, in areas of great disturbance and so thoroughly
metamorphosed as the one under consideration, do not readily
yield clear results ; but it is hoped that even the facts recorded
here may add something to the small sum of our knowledge of
these interesting formations, and that thereby a somewhat clearer
understanding of their geologic relations may be attained.
From the standpoint of the prospector, miner, or land-owner,
whose interest in such matters is eminently practical and whose
geologic training is entirely the result of work and observations
in the mines themselves, it is hoped that this presentation of facts
may be found useful, and that the mining interests of every section
may be advanced by a study of conditions existing in other por-
tions of the field. In fact, this method of comparison has been
found the only practical guide in the search for new localities or
in the development of deposits already known. If the rocks and
associated minerals of a given locality are the same as found in a
corundum mine, the prospector goes to work on the hypothesis that
the occurrence there of corundum itself is entirely probable.
While characteristic differences are everywhere observed between
mines, even in the same immediate neighborhood, yet experience
has shown that the conditions for the occurrence of corundum are
practically the same throughout the region. The few important
GEOLOGIC SKETCH OF THE CORUNDUM REGION. 11
exceptions to this rule are noted further on in describing the
modes of occurrence.
For the reasons suggested, then, it has been thought advisable
to publish the facts gathered in the field, along with some general
observations on the geology of the region and the characteristics of
the corundum-bearing rocks, rather than hold these for the appear-
ance of the final report. A knowledge of the facts cannot but
advance the interests of legitimate mining, as well as prevent such
waste of time and money as may sometimes be observed in western
North Carolina.
At the present writing, the only active corundum mining in the
world is in this State, and, with the important exception of
Georgia, North Carolina has supplied the only corundum on the
market since the beginning of the industry more than twenty years
ago. Besides regular mining, much work has been done in explor-
ing and prospecting, and considerable investments have recently
been made with a view to engaging in active mining at an early
date. Explorations have never been more actively prosecuted and
it is not unlikely that production .will be largely increased in the
near future by the opening of new mines. That there is abundant
demand for such increase is shown by the fact that, in addition to
the available corundum, there are annually imported for consump-
tion in the United States from 3,000 to 5,000 tons of emery, which
is practically the only mineral product that competes with corun-
dum in the market.
The combination of circumstances favorable to mining and
milling operations in North Carolina — the equable climate and
the almost universal presence of water-power — together with the
great superiority of corundum as an abrasive, combine to place
these formations among the important resources of the State.
2. GEOLOGIC SKETCH OF THE CORUNDUM REGION.
From the accompanying map it will be seen that what we may
term the Corundum belt in North Carolina is confined to a broad
strip of gneisses lying chiefly west of the Blue Ridge and extend-
ing northwestward from the Georgia boundary through Clay,
12
CORUNDUM AND BASIC MAGNESIAN ROCKS.
Macon, Transylvania, Jackson, Haywood, Buncombe, Madison,
and Yancey counties, while the peridotites with their character-
istic chromium- and nickel-bearing minerals, asbestos, etc., extend
the belt through Mitchell, Watauga, Ashe, and Alleghany coun-
ties to the Virginia line.
This belt is but a portion of the greater belt of crystalline rocks
which is coextensive with the Appalachian mountain system (see
plate II), and which, on account of its complex and highly crystal-
line character, is generally considered to be of Archean age. The
southern extremity of this belt disappears under the younger
formations in central Alabama. Its principal constituent is gneiss,
often, through higher development of lamination, passing into
schists, and including frequent masses of granitic and other dis-
tinctively igneous rocks.
These gneisses have been usually considered to be, in great part,
sedimentary rocks that have lost their original clastic characteris-
tics, with the possible exception in some cases of bedding, in the
great earth-movements and other metamorphosing agencies in
which they have been involved. Some of them, however, are
certainly granites or other massive rocks that have been sheared
or squeezed by the same agencies — transitions from the massive to
the laminated forms being often easily observed and, in fact, almost
universally present about the borders of the massive rocks of the
region.
When these changes have affected the whole of such an igneous
mass, it is obvious that a rock will result that will often be difficult
and sometimes impossible to distinguish, in the field, from a meta-
morphosed sediment of similar composition. As yet the geology
of this area is not sufficiently known to map these varieties
separately; though such distinctions are highly desirable in con-
sidering the questions of origin of some of the massive rocks and
their relations to the prevalent structural types of the region.
By the earlier geologists, the lamination of the gneiss was con-
sidered true bedding, and their attempts to interpret the structure
of the region were based on this misconception. It is well known
that lamination is often developed where no such original struc-
ture existed, as in the sheared massive rocks alluded to above. It
GEOLOGIC SKETCH OF THE CORUNDUM REGION. 13
is also known that such structure produced by movement in the
mass of the rock may, and usually does, obliterate whatever origi-
nal structure may have been present ; so that a sedimentary rock
thus mechanically laminated and at the same time thoroughly crys-
tallized would no longer show its original stratification. The new
structural planes might correspond in certain cases with bedding,
but often they would not ; and hence the strikes and dips observed
in this region and recorded here, being those of lamination planes,
are not in any case to be interpreted as true strikes and dips.
The prevailing strike of the lamination planes in the gneiss of
western North Carolina is about north 30° east, and the prevailing
dip is at a high angle toward the southeast. Yery frequently
local variations occur, especially in the dips, and often the preva-
lent southeasterly dip will become vertical and, tipping over, will
pass into a northwesterly dip within an outcrop of only a few feet.
All stages occur from these local variations in dip and strike to the
most gnarled and contorted forms imaginable. In general, the
lamination has suffered the most deformation in the immediate
vicinity of igneous intrusions ; or perhaps the statement might be
reversed, as the forces that produced the contortions doubtless
formed simultaneously the fissures into which the massive rocks
were injected.
Constituting a small proportion of this belt, as regards area, are
the basic magnesian rocks, chiefly peridotites, which are here
specially considered in their relations to the occurrence of corun-
dum. These occur in small lenticular masses or in narrow strips,
rarely exceeding a mile or two in length, and, so far as I am aware?
are nowhere intimately associated with the well recognized
igneous rocks of the granitic type. Contortions are observed,
however, in the adjacent gneisses similar to those in the vicinity
of granites, and often a transition to mica-schist gives evidence of
an unusual amount of movement.
The magnesian rocks, too, whether peridotites or pyroxenites,
have always a sheath of schistose talc developed about their bor-
ders and, in the corundum-bearing region, also much chlorite.
Hence there is never, as far as observed, an absolute contact be-
tween these massive rocks and normal irneiss.
14 CORUNDUM AND BASIC MAGNESIAN ROCKS.
South of Virginia, the gneissic belt is flanked on the west by a
broad strip of partially metamorphosed but generally distinct sedi-
ments of undetermined geologic age. No fossils have yet been
found in them and structures are greatly confused by disturbances
that have given rise to the Appalachian system of mountains.
Hence their relations to the known Paleozoic rocks, by which, in
turn, they are bordered on the west, is, as yet, a matter of contro-
versy. These beds consist of a lower series of shales and lime-
stones lying uncomformably on the gneisses, and followed by con-
glomerates and sandstones above. To the whole formation the
name Ocoee has been given.
Referring again to the map (plate I.), it will be seen that two belts
of Ocoee are developed in western North Carolina ; the one, lying
along the Tennessee border, a broad area of irregular outline and
tapering northward to a point just south of Johnson City, Ten-
nessee. Beyond this point, as far as the boundary has been traced
northward, the paleozoic formations lie directly in contact with
the gneisses. The other Ocoee belt forms a narrow strip lying
about forty miles further east in its southern portion, and passing
northwestward from the upper French Broad valley, approximately
in the direction of the Blue Ridge. The irregular boundary of the
western area brings the two belts within twenty-five miles of each
other in places, but the general trend of them both is the same as
that of all the rocks of the region, and corresponds to the axes of
Appalachian folding.
The eastern belt is exceedingly narrow in its southern portion,
perhaps even narrower in places than indicated on the map, but
it broadens northward and becomes involved in extremely com-
plex folds and faults in Mitchell and Watauga counties. It should
be stated that, north of the 36th parallel, as the detail on the map
would indicate, the boundaries of this belt are much more accu-
rately determined than in its southern extension. East of this
narrow strip of Ocoee, comes a broad expanse of gneisses and
granites, extending beyond Charlotte, Salisbury, and Greensboro,
and forming the Piedmont plateau region of the State.
The corundum-bearing peridotite belt lies wholly within the
strip of gneiss between these two belts of Ocoee. Almost the
THE PERIDOTITES AND ASSOCIATED MASSIVE ROCKS
15
whole width of this strip in the southwestern portion of the State
is thickly dotted with small peridotite areas, but north of
Waynesville they become more irregular and scattering. The
manner of distribution is shown on the map, but, for the sake of
clearness, the areal proportions are there often necessarily exag-
gerated. This is especially true of the schistose talc and chlorite
rocks, which seldom exceed twenty or thirty feet in width of out-
crop.
3. THE PERIDOTITES AND ASSOCIATED MASSIVE ROCKS.
As the corundum deposits of the State are found chiefly in con-
nection with these rocks, it is important, before passing to the con-
sideration of these deposits, to give brief descriptions of the perid-
otites and related rocks, in order that the descriptions of mines
that follow may be more fully understood.
The rocks to be considered may be classed in three groups,
namely : peridotites, pyroxenites, amphibolites . Of these, the first
group largely predominates, and the others are regarded as only
variant or accompanying forms of the same geologic unit. They
sometimes, however, attain considerable importance as independ-
ent rock masses.
(1.) THE PERIDOTITES.
The peridotites appear in numerous small oval or lenticular
masses of dimensions rarely exceeding a few hundred feet. Some-
times these lenses merge into each other and form a narrow strip
a mile or two in length with constrictions at intervals, thus resem-
bling, in form, a string of sausages. In rare cases, the outcrops pre-
sent an irregular boundary, and cover areas of several hundred
acres. The Buck creek area in Clay county, and that at Webster
in Jackson county, are the largest masses of the belt, and their
form and extent are shown approximately on the small scale
map, plate I. (See also plates III and V.)
These rocks are in general perfectly massive and structureless,
though a parallel structure is often developed about the borders;
and at Webster the whole mass is so perfectly laminated as to pre-
16
CORUNDUM AND BASIC MAGNESIAN ROCKS.
sent a striking resemblance to a thin-bedded sandstone. As stated,
however, this structure is exceptional, even the small bodies and
narrow strips preserving a perfectly massive character.
This is often true, even where there has been considerable move-
ment along the contacts between the gneiss and peridotites, result-
ing in the frequent development of mica-schist in the adjoining
gneisses and the universal presence of schistose talc in the borders
of the dunite. The boandaries have thus become veritable slick-
ensides, and hence no true contacts between the peridotites and
gneisses have been observed, and original contact metamorphism,
if such ever existed here, has been entirely obliterated.
The peridotites of North Carolina represent a petrographic unit;
and no extensive field work is necessary to convince one that any
attempt to subdivide them must proceed on comparatively slight
mineralogical differences, and the classes established regarded as
mere varieties. Thin sections cut from different portions of the
same outcrop might be made the basis for the establishment of
three or four petrographic divisions; but, in the field, the lines of
separation cannot be sharply drawn. The classes made in the
laboratory are found to merge into each other, forming parts of
the same rock mass.
However, with a clear understanding of this unity, the estab-
lished classification of the peridotites may be useful for purely
petrographic purposes; and, in deference to usage, the more prom"
inent types observed in the State are here considered separately
These are dunite, the pure olivine rock; harzburgite (saxonite),
that composed of olivine and orthorhombic pyroxene; amphihole.
picrite, consisting essentially of olivine and hornblende ; forell-
enstein (troctolite),the olivine-feldspar rock, which is not a peridotite
according to the definition of that class; namely, that it consists o*
olivine rocks without essential feldspar. Forellenstein is usually
regarded as a phase of olivine-gabbro produced by the suppression
of the pyroxene — indeed, it may be questioned whether most perid-
otites should not also be so considered — but on the ground of geo-
logic unity, it is here classed with the peridotites.
THE PERIDOTITES AND ASSOCIATED MASSIVE ROCKS. 17
a. DUNITK.
The type of this rock was discovered in Dun mountain, New
Zealand, about thirty years ago, and described by von Hochstetter as
a light yellowish-green to grayish-green, crystalline granular rock,
with an oily to a glassy lustre, and an uneven angular fracture.
The dull, rust-brown color of the barren, weathered surface gave
the mountain its name and, indirectly, the rock itself. It was
found to consist almost exclusively of granular olivine, with chrom-
ite or picotite, in octahedral crystals the size of a pin-head, scat-
tered through the mass.
The North Carolina dunite is very close to this type. It is
usually composed of quite small grains of olivine, about the size
of granulated sugar, though sometimes much coarser rock is found
in small quantities, and large grains are often scattered through
the fine-grained masses.
Small octahedrons or rounded grains of chromite or picotite are
sparsely scattered through nearly all the olivine rocks. Sometimes
these become very plentiful, and are then frequently segregated
into vein-like streaks or pockets, and attain importance as a chrom-
ium ore. Long, glistening needles of tremolite are often observed,
and sometimes flakes of talc and chlorite.
The colors include nearly all shades from light brownish yellow
to a dark green, though the freshest specimens seem to be those of
light oil-green or yellowish green color. Brown and yellow tints
are generally more superficial and seem to be the results of oxida-
tion of the iron constituent in the incipient stages of decomposi-
tion ; and a dark green color may sometimes be seen, by the aid of
a lens, to be the result of a partial alteration to serpentine. The
dark green, fine grained varieties are usually tough, and the coarser
grained, yellowish ones are very friable, being often easily crumbled
with the fingers, even when apparently quite fresh. The more
thinly laminated varieties about Webster and elsewhere are usually
partly altered and quite friable also.
The characteristic dull brown color of the weathered surface is
the same here as described for the New Zealand rock. By decom-
position, an ochreous soil is produced which, on account of its
18 CORUNDUM AND BASIC MAGXESIAX KOCKS.
infertility and the cod sequent absence of vegetation, is easily
removed by rains ; and hence the outcrops are nearly always made
conspicuous by barren areas of brown, angular rocks in a region
otherwise well wooded.
Under the microscope, in ordinary light, dunite is seen to consist
of irregular, angular grains of translucent, colorless olivine. In the
fresh specimens, the angles of these grains fit accurately into each
other with no interstitial matter whatever (Plate VI, figure 1);
though in the great majority of cases there has been a slight alter-
ation along the cracks into serpentine, and this secondary material
surrounds every grain completely like mortar in a rubble wall.
(Plate VI, figure 2.)
The microscope also reveals the fact that many of these rocks
now of fine texture have resulted from cracking up the grains of a
much coarser rock. In this process the remnants of these origin-
ally large grains have suffered very little or no displacement, for
in polarized light they still extinguish together over considerable
areas. (Plate VI, figure 3.) In some cases, however, these frac-
tured grains have also been slightly sheared, and, hence, of course,
the small fragments have rolled somewhat on each other and the
evidence of its having once been a coarse grained rock is more or
less completely obliterated. Sometimes, too, these grains show the
development of a distinct cleavage parallel to the brachypinacoidal
plane of the crystal ; and more rarely, a basal cleavage is devel-
oped at right angles to this.
Besides olivine, either chromite or picotite, while neither is an
essential constituent of dunite, is always present in rounded grains,
occasionally in crystals, scattered through the rock ; and hence
they must be regarded as characteristic accessories. The distinc-
tion between these two minerals under the microscope, if indeed a
sharp line may be drawn between them at all, is often quite diffi-
cult to make. No chemical or other special investigations have
yet been made in connection with this work, and the two names
are used rather loosely in the descriptions of microscopic
characters of the rock. A review of a considerable amount of
literature on similar studies shows quite a prevalent indefinite-
ness in referring to these minerals, and emphasizes the need of more
THE PERIDOTITES AND ASSOCIATED MASSIVE ROCKS. 19
thorough chemical and microscopic investigation for the purpose
of establishing definitely the relations between them.
In the study of these North Carolina rocks, I have called the
opaque mineral that shows a dull grayish color by reflected light
chromite / and for all those varieties that are translucent and of a
yellowish or reddish brown color I have used the name picotite.
The thoroughly unsatisfactory nature of this classification is more
readily understood when it is found that every possible gradation
between the bright yellowish brown, translucent mineral and the
dull, opaque one are found in the same rock, and, indeed, may
often be seen in the same thin section. The most natural explanation
of these facts seems to lie in the hypothesis that we have here a
complete chemical series, as pointed out by Wadsworth* ; and
further wTork on the chemical relations of these minerals, to be of
the greatest value, should also take into account their microscopic
characters.
In some of the oli vine-feldspar rocks described below, the rela-
tions are even more striking than this ; for quite frequently the
clear, translucent picotite is surrounded by a border of opaque min-
eral with a sharp line between them, and the width of this border
varies from a thin peripheral line to a band so broad that there
appears only a minute grain of translucent mineral in the middle.
The size of the grains of chromite, or picotite, as the case may
be, usually does not vary very widely from that of the olivine
grains, though sometimes they are conspicuously larger. This is
usually true where the quantity present is largely in excess of the
normal, so that prominent segregations of it appear, sometimes
attaining the importance of an ore, as mentioned above. Masses
of such ore have been found in the vicinity of Webster, in Jack-
son county ; near Burnsville, in Yancey 'county ; northwest of
Boone, in Watauga county, etc.
Other accessory constituents of dunite which are seen under the
microscope, and which sometimes become prominent macroscopi-
cally, may be briefly mentioned. Enstatite in irregular grains is
quite often seen, and is sometimes pleochroic. Less often, diallage
is found. A light green hornblende, in elongated prisms, and giving
*Lithological Studies, Cambridge, 1884, pp. 176-186.
20 CORUNDUM AND BASIC MAGNESIAN ROCKS.
under the microscope properties of aetinolite, is often found in the
rock at Buck creek, Clay county, and sometimes on Shooting creek.
The minerals described above are the only ones that have been
at all commonly observed in the perfectly fresh dunite. As soon
as alteration begins, there appear a considerable number of new
minerals among the secondary products; and, as has been already
mentioned, at least some alteration may be seen in most of the
sections when examined microscopically.
By far the most prevalent product of alteration, and one that
is to a certain extent well-nigh universal, is serpentine. The first
stage in serpentinization of the olivine is seen in the narrow line
of yellowish or greenish, low-refracting substance that appears
along the borders of the grains, forming a fine network, which
completely envelops the olivine. Later, it forms along the irreg-
ular fissures and cleavage cracks through the individual grains
themselves ; and gradually, as these are altered more and more
along their borders, the serpentine replaces the olivine till no
trace of the original mineral is left.
In the earlier stages, this alteration is very common, almost
universal, in the dunite; but, in North Carolina, complete altera-
tion, save in a few small areas, is exceptional. The process is sel-
dom carried so far as to destroy the granular, sandy nature of the
rock over any considerable area. Plate YI (figures 1, 2, 4, and
5,) shows successive stages in this process, together with some of
the characteristic phenomena that attend it. A deposition of mag-
netite in fine grains in the beginning of the alteration is very com-
mon, and a net-work of black lines is thus formed that often out-
lines the original olivine grains after the whole has passed into
massive serpentine. Sometimes the rejected ferruginous materials
take the form of a lower oxid and stain the serpentine and also
the olivine remnants a deep yellowish brown. Where cleavages
are developed in the olivine, the alteration to serpentine usually
takes place more readily along that parallel to the basal plane,
though the brachypinacoidal cleavage is always more highly
developed.
The same difference in resistance to chemical action along these
two planes is observed in the development of chlorite in the olivine.
*J1 OTVJX Q
StaU faibrary,
THE RERIDOTITES AND ASSOCIATED MASSIVE ROCKS. 21
Chlorite is often present in the partially serpentinized specimens
and also in many cases where there is no serpentine. The horn-
blende-bearing variety (amphibole-picrite) generally shows more
or less alteration of the hornblende to chlorite, and sometimes only
scattered remnants of it are left entirely surrounded by the sec-
ondary product.
But chlorite is often distinctly the result of alteration of the
olivine also, as seen in its frequent development along cracks and
cleavage planes ; and still more conclusively in those cases where
the chlorite penetrates the solid olivine grains and gradually
replaces them, much in the same manner as serpentine. In such alter-
ation there is, of course, an accession of alumina from some source
outside of the olivine itself, this mineral being simply a combina-
tion of the silicates of iron and magnesium in varying proportions
and entirely free from alumina. The same is true of the produc-
tion of talc, which is much less frequent in these rocks. With the
formation of chlorite there also occurs a segregation of the fine
grains of magnetite into irregular patches or large grains, and
these are frequently given a skeleton appearance by the laths 01
chlorite that penetrate them. Such masses of magnetite are almost
universally surrounded by a zone of chlorite or a mixture of chlo-
rite and talc, in radiating fibres approximately at right angles to
their boundaries.
Tremolite, in long slender needles, is often present with serpen-
tine and chlorite, and is sometimes largely developed where very
little of the other two has be enformed. Its secondary nature is
unmistakable, in most cases, from the manner in which it pene-
trates the olivine grains in every direction, often passing through
several in succession without reference to the orientation of cleav-
ages or crystallographic axes. The tremolite, in turn, is frequently
more or less altered to talc and chlorite ; and most of the speci-
mens showing talc also bear some tremolite, so that such alteration
may often, though not always, account for the presence of talc in
dunite. In some cases it is evidently the result of alteration of
enstatite, as shown by remnants of the original mineral and by the
form which the talc still retains.
Enstatite, in some cases at least, is a secondary product, as often
22
CORUNDUM AND BASIC MAGNESIAN ROCKS.
seen in the radial casing which it forms along the joint-planes
of the dunite. This is especially prominent at the north end of
Corundum Hill, and is more or less developed in a great many of
the outcrops throughout the State.
The casing varies from an inch or less in thickness to 12 or 14
inches, and generally contains more or less chlorite in scattering
scales through it. It is always fibrous in structure, with the fibres
arranged approximately normal to the surface of the enclosed
dunite ; and may sometimes be separated into two or more con-
secutive layers, practically identical in structure and composition.
The outer portions of these casings are often altered to talc, and
sometimes this has been rendered schistose by subsequent shearing
so as to wrap these portions round the boulders in thin laminae.
Such layers are seen to be continuous with the unaltered portions
of the casing which still stand perpendicular to the surface of the
enclosed block of dunite.
Casings of this nature are often broken through in mining for
corundum, and the enclosed block found to be completely altered
to a yellow ochreous earth that easily crumbles on exposure. The
connection of this enstatite with the corundum veins will be dis-
cussed later in describing the modes of occurrence of corundum.
Carbonates in small quantities, sometimes forming little veins
through the rock, are found in the specimens that have suffered
considerable alteration. They are readily recognized under the
microscope by their high double refraction and well-developed
rhombohedral cleavage. ~No tests were made of their chemical
nature, but they are doubtless ordinary magnesium carbonate, or
magnesite.
In the final weathering and disintegration of dunite, silica, in
the form of chalcedony, is deposited in irregular masses in he
joints and cracks; and garnierite, genthite, and other nickel bear-
ing silicates are formed in cases where the olivine carries small
quantities of nickel. These minerals, however, never form impor-
tant rock masses, though the nickel minerals have been found in
sufficient quantity in some localities to attract attention from a
commercial standpoint.
The original minerals and alteration products described above
THE PERIDOTITES AND ASSOCIATED MASSIVE ROCKS. 23
are found in practically all the dnnite localities of the State ; in
fact, there is remarkably little variation in the characters of the
rock throughout the region, much less than in the corundum and
its associated minerals. Such variations as do exist are chiefly in
the relative proportions of the various minerals resulting from
alternation rather than in the original constitution of the rock,
and important characters of this nature will be pointed out below
in enumerating the peridotite localities.
b. harzburgite (Saxonite).
This is essentially an olivine-enstatite rock and is found in this
region chiefly as a transition between the dunite and the enstatite
rock described below, though there are a few exceptions and these
are of sufficient extent and importance to warrant a separate con-
sideration. The two principal constituents occur in very variable
proportions, and, besides these, all the accessory minerals of dunite
are also present. The olivine, chromite, etc., are identical with
the same minerals as found in dunite, and the enstatite has the
same essential characteristics. But here it is much more highly
developed and becomes an essential constituent, being always pres-
ent in macroscopic dimensions, and prominent for its glistening
cleavage faces.
The alteration processes are the same as for dunite. The ensta-
tite alters in some cat-es to serpentine, just as described for olivine,
but oftener it changes to talc. This is especially true of the ensta-
tite in the pyroxenites described below. Harzburgite is found
principally in large outcrops near Bakersville, Mitchell county, and
near Elk Cross Roads, Ashe county; Balsam Gap, Jackson county;
and Mine creek, Yancey county.
C. AMPHIBOI,E-PICRITE.
This rock is very similar in structure to the harzburgite described
above, an amphibole (hornblende) mineral, resembling actinolite,
replacing the enstatite as an essential constituent. Enstatite is
frequently present, however, and the grains and crystals of chromite
or picotite constitute characteristic accessories, as in dunite. The
24
CORUNDUM AXD BASIC MAGXESIAX ROCKS.
hornblende is often partially or wholly altered to chlorite, and it
is very probable that the chlorite of the olivine rocks of this region
may have originated often in this manner. A considerable por-
tion of the Buck creek peridotite mass, especially towards the
north end of the mountain, is composed of rock which conforms
closely to this type.
d. forKIvLExsteix (Troctolite).
This rock type, composed essentially of olivine and feldspar, has
been found in important development at only one locality ;
namely, on the eastern border of the dunite area at Buck creek,
in Clay county. It is also found in small amounts on Shooting
creek, where the rock associations are similiar in many ways to
those of Buck creek. The whole outcrop at the former place covers
an area of only about two acres, but it is interesting on account
of its connection with the dunite, instead of with gabbro, as usually
found, and also on account of the rarity of this type of rock.
So for as I am aware, this is the first recorded instance of forellen-
stein as a phase of peridotite.
The rock is composed almost entirely of olivine and a basic
feldspar (anorthite), and the zones of intermediate silicates devel-
oped along the borders between these minerals.
A small amount of feldspar that was separated by heavy solution
for analysis showed some kaolinization when examined with the
microscope, but the following partial analysis places it unmistak-
ably with anorthite.
Partial Analysis of Feldspar (Anorthite) from Forellenstein of Buck
Creek, Clay County, N. C.
Percentage On basis of 100
Determined. per cent.
Silica
40.40
18.72
36.40
42.29
Alumina
Lime
19.60
38.11
95.52
100.00
PYROXENITES ENSTATITE KOCK. 25
The percentages, calculated on a basis of 100, are only approxi-
mately correct for the pure mineral, as magnesia probably exists
in combination with part of the silica. The quantity available
was too small to give more than approximate results.
In this rock, the olivine nowhere borders directly on the feld-
spar, but it is separated from it by a double zone of fibrous miner-
als, arranged at right angles to the boundaries. Rarely, one
portion is absent and the minerals are separated only by a single
zone. Such reaction rims have been described often from olivine
gabbros, and their optical properties were carefully studied by Dr.
F. D. Adams, in an occurrence in the anorthosites of Canada,
which is exactly similar to this North Carolina rock, except that
the reaction rims of the latter are somewhat more highly developed
than in any occurrence heretofore described.
Dr. Adams found that the portion of this zone adjacent to the
olivine corresponded in optical properties with enstatite, and that
the other part is made up of a fibrous green hornblende. In the
North Carolina rock, this latter is sometimes perfectly continuous
with large cleavable masses of hornblende, and its identity is thus
easily recognized microscopically. But the other portion cannot
be satisfactorily determined without separation of the minerals
from the powdered rock, and this I hope to do before the publica-
tion of the final report on these rocks.
(2.) PYROXENITES.
Two types of this family are found in closest connection' with
the peridotites, and sometimes passing gradually into them, though
usually much more sharply differentiated than the different varie-
ties of the peridotite from each other. Two very distinct types of
pyroxenite have been observed, namely, that composed of ortho-
rhombic pyroxene, enstatite rock ; and, one consisting of both
monoclinic and orthorhombic pyroxenes, websterite.
a. ENSTATITE) ROCK.
This rock, as its name indicates, is composed chiefly of the ortho-
rhombic pyroxene, which is usually in large bladed, interlocking
2
26 CORUNDUM AND BASIC MAGNE8IAN ROCKS.
crystals of a grayish or yellowish color. In some places where it is
considerably developed it forms a mass perfectly continuous with the
dunite, as at Corundum Hill, Macon county, and in some of the
outcrops of the Sapphire mine in Jackson county. At other
Sapphire localities, and especially in Transylvania and Watauga
counties, it forms separate rock masses of considerable extent.
Besides occasional grains of olivine and chromite, this rock scarcely
contains anything else than enstatite and its alteration products.
The alteration consists entirely, so far as observed in this region,
of a change into talc. Even the freshest looking specimens often
have greenish, transparent talc developed in them, and frequently
large masses that have undergone this alteration still retain
perfectly the form and appearance of the original mineral. This
is often true also of talc in enstatite-bearing peridotite (harzburg-
ite), as may be seen in that near Balsam gap, in Jackson county.
Dr. C. D. Smith considered the chief constituent of this rock to
be anthophyllite,* and the same term has been employed by some
later writers. Rocks of a similar character at the Pine Mountain
mine, Rabun county, Georgia, are also called anthophyllite by Mr.
Francis P. King.*
In view of this usage and the extreme scarcity of well deter-
mined localities for true orthorhombic amphibole, I had a specimen
of the mineral from Corundum Hill analyzed in the laboratory of
the Survey by Dr. Charles Baskerville, with the result given below
in column I. Talc could be seen in small amounts in the specimen
from which the sample was taken. This was carefully excluded
from the material analyzed, but the high percentage of water shows
that considerable alteration had taken place. There can be no
doubt, however, of the true character of the mineral. Deducting
the water and calculating the percentage on the basis of 100, we
obtain the results given in column II., and these figures represent
a normal enstatite with a high iron constituent, and near the
bronzite variety.
*Report Geol. Sur. N. C L, 1875, appendix, page 93.
♦Bulletin 2, Geol. Sur. of Georgia, 1894. pages 79, 82, etc.
PYKOXENITES WEBSTERITE.
27
An analysis of another specimen from the same locality by Mr.
Frank Julian* is given in column III, for comparison.
Analyses of enstatite from Corundum Hill, Macon county :
I.
II.
III.
Silica
51.64
0.12
9.28
0.45
31.93
0.56
5.45
54.95
57.30
Alumina
trace
Ferrous oxid
9.87
7.45
Lime
Magnesia
33.97
34.64
Manganese oxid
Water
1.21
99.43
100.60
No other specimens have been determined, and the name is
applied to rocks of other localities on general resemblance. It
is possible that some of them may prove to be of a different nature.
b. WEBSTERITE.
This rock was first described and named by the late Dr. G. H.
Williams from specimens collected at Webster, Jackson county.*
Thus far, besides the type locality near the town of Webster, it
has been observed only in the continuation of the same outcrop of
dunite on Cnne creek, about six miles further east. It is composed
of both orthorhombic and monoclinic pyroxenes in a compact, gran-
ular mass, closely resembling the dunite with which it is associated,
and forming a part of the same rock mass. So far as observed,
however, there is no gradual transition from one to the other, the
two types remaining quite distinct.
The Webster dunite, as before stated, is very highly laminated,
and in the midst of this rock, which appears on a hillside facing
the Tuckaseegee river in an outcrop over 1,500 feet wide, the web-
sterite occupies a width of about 300 feet. It may be traced for
about a mile in length, in this type locality ; then it thins out and
does not appear again, except in the Cane creek outcrop mentioned
♦Bulletin 74, TJ. S. Geol. Sur., Minerals of North Carolina, 1891, page 43.
♦American Geologist, VI, 1890, pages 41-44. .
28 CORUNDUM AND BASIC MAGNESIAN ROCKS.
above. It is more massive in character than the dunite, has a more
brilliant green color, and is less altered on the surface. It is also
quite prominent in the field, owing to the vigorous vegetation
which it supports, in contrast with the barren dunite.
(3.) AMPHIBOLITE.
This term is here used to indicate massive rocks composed
wholly or chiefly of amphiboles. The most important to be
considered here is the beautiful green, feldspathic, hornblende
rock, which often bears pink and red corundum in the Shoot-
ing creek and Buck creek localities of Clay county. It is
principally composed of grass-green hornblende and the lime-
feldspar, anorthite, in greatly varying proportions ; and its struc-
ture is usually laminated and gneissic, though massive forms are
not entirely wanting. The corundum which it bears occurs in
masses from the minutest microscopic grains to broad cleavable
plates three or four inches in diameter.
The rock is very fine-grained and exceedingly tough ; and, hence,
it has not been found practicable to crush it for the separation of
the corundum. Transitions from this type to the dunite, with
which it occurs, are found on top of the mountain west of the mine,
at Buck creek. The intermediate stages have about the same com-
position and structure as the forellenstein described above ; but
they never assume sufficient importance in this connection to be
classed as a separate rock. The relations of this rock to the dunite
(see map, plate III) is strongly suggestive of a system of dikes
cutting the latter. On Shooting creek, Clay county, it usually
occurs in narrow strips beside the dunite, though sometimes in
masses of equal size.
The hornblende of this rock has usually been referred to the
species smaragdite* but analyses show it to be an aluminous horn-
blende, and the late Professor Dana classed it with edenite. The bril-
liant color is undoubtedly due to the chromium present. This is more
plainly seen when the powder of the rock is examined under the
*F. A. Genth, Bulletin 74, U. S. Geological Survey, 1891, 45. F. P. King, Bulletin 2, GeoL
Survey of Georgia, 1894, 44, 45.
AMPHIBOLITES.
29
microscope. When the mineral is separated from this powder with
heavy solutions, the heavier fragments are all seen to contain
inclusions of picotite in minute grains, and to be of a much
brighter green immediately around these inclusions. This will
account for some of the chromic oxid found in analyses. The
purer mineral thus separated was analyzed by Dr. Charles Basker-
ville, with the results given in column I. That in column II is an
analysis of the same mineral (without separating the grains with
picotite) given by Dr. Grenth in the bulletin referred to above.
Analyses of Aluminous hornblende from Buck creek, Clay county :
I.
II.
Silica
44.38
17.32
0.38
3.83
45.14
Alumina
17.59
Chromic oxid
0.79
Ferrous oxid
3.45
Nickelous oxid
0.21
Magnesia
15.48
0.90
11.51
1.24
0.38
4.63
16.69
Manganese oxid
Lime
12.51
Soda
2.25
Potash
0.36
Water
1.34
Specific gravity
100.03
3.075
100.33
3.120
The specific gravity given by Dr. Genth was determined on the
grass-green variety, and it is natural to suppose that picotite inclu-
sions cause the greater weight as well as the higher chrome per-
centage. Feldspar was separated and found to agree both in spe-
cific gravity and extinction angles with typical anorthite.
30 CORUNDUM AND BASIC MAGNESIAS' ROCKS.
4. ASSOCIATED SECONDARY AND SCHISTOSE ROCKS.
Besides the schistose phases of the massive rocks described
above, there are found frequent large masses of talc- and chlorite-
schists in connection with the typical dunite, as well as with the
other associated rocks. Serpentine is extensively developed in only
one portion of the region, and is evidently an altered dunite.
(1.) MASSIVE ROCKS.
a. SERPENTINE.
Massive serpentine is almost the universal result of exposure of
olivine rocks to hydration process. These rocks in Xorth Car-
olina have been subjected to this alteration in but few places.
Throughout the greater portion of the belt, the outcrops of the
peridotites are almost perfectly fresh to the very surface of the
exposure ; and such alteration as has taken place is usually in the
nature of a direct decomposition of the olivine, forming magne-
sium carbonate, which is mostly carried away in solution, and a
residue of. limonite and silica, the latter remaining as chalcedony.
As stated in the description of dunite, however, most of the sec-
tions of this rock show, under the microscope, some slight altera-
tion to serpentine along the cracks; and it seems quite probable
that this is the first stage in the decomposition and disintegration
of the rock through ordinary weathering processes.
The production of serpentine scarcely reaches a greater develop-
ment, in the majority of cases, than to form a thin net-work along
the cracks of the olivine ; and this is seldom perceptible to the
naked eye. On the most exposed surfaces, where the rock is super-
ficially stained by the iron oxids of the decomposing olivine, the
typical granular structure is still retained; and, with the excep-
tion of a small area at Buck creek, Clay county, there is no devel-
opment of massive serpentine south of Waynesville.
But very different conditions have evidently prevailed somewhat
further north ; for in Buncombe, Madison, and Yancey counties
we find these granular rocks largely altered to typical, massive
ASSOCIATED SECONDARY AND SCHISTOSE ROCKS. 61
serpentine. The outcrops appear in the same form as found in the
olivine rocks, and the characteristic chromite grains are always
present. Under the microscope, thin sections often also show the
original granular nature of the rock in the net-like or "mesh"
structure of the fibrous serpentine bands that were first formed
around the olivine grains. This structure is still more emphasized
if, as is often the case, in the early stages of serpen tinization, there
was a separation of magnetite or other ferruginous material along
these bands.
A serpentine retaining quite a large percentage of unaltered
olivine is found on Ivy river, in Madison county. Sections of this
rock, seen under the microscope, have the appearance of that
shown in plate YI, figure 4 ; and, in some cases, the olivine
grains are quite distinctly seen with the unaided eye.
However, most of the serpentine represented on the map, espe-
cially that in the vicinity of the French Broad river below Ashe-
ville, is massive and of light to dark green color, and is in every
way similar to that of Maryland and Pennsylvania, in the north-
ward continuation of the belt. In these States, it is quarried for
architectural purposes, and may be seen in many buildings in the
cities of Washington, Baltimore, and Philadelphia. There would
seem to be no special reason why the serpentine of North Carolina
should not be used in the same maimer, especially wThere trans-
portation facilities are good. Stone of good color is available in
many of the localities indicated on the map ; but thus far, no
attempt has been made to utilize it.*
Many people in the corundum region of North Carolina use the
term serpentine indiscriminately, and in most cases incorrectly, for
any rock of the peridotite belt, especially when associated with
corundum.
*See "Notes on Building and Ornamental Stone,11 by J. V. Lewis. 1st Biennial Report of
the State Geologist, 1893, pages 101, 102.
32
CORUNDUM AND BASIC MAGNESIAN ROCKS.
(2.) SCHISTOSE ROCKS.
a. TAI.C-SCHIST, SOAPSTONE.
As already mentioned in the geologic sketch of this region,
there is always a greater or less development of talc along the
boundaries of the peridotites and pyroxenites, separating them from
the gneisses of the country. But there are considerable masses of
enstatite rock sometimes entirely altered to talc. Such rocks may,
and sometimes do, retain the form and appearance of the original;
but generally they have been rendered schistose by subsequent
shearing.
Besides these larger masses, narrow strips of schistose talc are
very generally developed along lamination of the gneisses as a con-
tinuation of the outcrops of the magnesian rocks; and these some-
times connect two or more lenticular masses of dunite or pyroxenite
across intervals of two or three miles. The width of such strips
seldom exceeds ten or fifteen feet, and is very frequently less.
They are composed of rather pure, white and grayish talc, and are
always schistose. Their chief importance, of course, lies in their
close connection with the massive rocks. All the talcose rocks,
frequently the chloritic schists, and sometimes even the peridotites
are locally termed "soapstone," or "serpentine."
In many portions of the peridotite belt, especially in the north-
western counties of North Carolina, soapstone of the firmer and
more massive varieties assumes considerable importance on account
of its extensive local use. Its great resistance to heat makes it a
most enduring material for the construction of fireplaces ; and its
use for this purpose is almost universal in regions where it can
be readily obtained. It is easily cut into desired shapes with
ordinary saws, axes, and planes, such as are used in wood-work.
While the copper mine was operated at Ore Knob, Ashe county,
great quantities of soapstone were used for furnace linings, all of
which was cut from the neighboring peridotite belt in Ashe and
Alleghany counties. This material also finds an extensive local
use for tombstones on account of the ease with which it is shaped
and lettered.
N. C. GEOLOGICAL SURVEY.
BULLETIN 11, PLATE II.
/
DISTRIBUTION OF PETtLDOTITES AND ASSOCIATED EOCKS. 33
b. CHLORITE-SCHIST.
Where corundum is found in connection with dunite, there is
always more or less chlorite developed about the borders of the
rock mass and through the larger joints ; but the chlorite itself, in
such cases, never assumes the importance of a rock. In certain
localities, however, especially on the waters of the Tuckaseegee
river above Webster, there are narrow strips of chlorite rock, com-
parable in many ways to those of talc described above, but in no
way connected with known olivine rocks. They are apparently
independent masses, usually schistose in character, and sometimes
bear corundum. In these cases the corundum is surrounded by
alteration zones of muscovite, but, besides the chlorite, the rock
has no other prominent constituent. The chlorite rocks are often
talcose, and sometimes pass over into the type described above.
Whether talcose or not, they are usually known to the people as
"blue soapstone." ,
5. DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS.
(1.) IN THE APPALACHIAN BELT.
A great peridotite-serpentine belt, coextensive in length with
the Appalachian mountain system (see map, plate II), traverses the
crystalline schists and gneisses from Tallapoosa county in eastern
central Alabama, where these rocks emerge from beneath the later
formations to the southward, to Trenton, New Jersey, where they
disappear for a space under the younger sedimentary rocks to the
northward. Throughout this distance of over 800 miles, the perid-
otites are found along a narrow belt of disconnected outcrops
with an approximate trend of north 45° east.
In the southern half of this belt, dunite is the prevailing type of
rock, but in Virginia, Maryland, and Pennsylvania, it is repre-
sented only by the secondary forms — serpentine and talc rocks.
Chromite is almost a constant accompaniment throughout the
region, and in Pennsylvania, North Carolina, South Carolina,
Georgia, and Alabama, corundum is also found in the same
connection.
M
CORUNDUM AND BASIC MAGNP]SIAN HOCKS.
With the reappearance of the crystalline belt, we find serpentine
again at Hoboken, New Jersey, and on Staten island. Other
occurrences of a similar nature are found in northern New York,
Massachusetts, Vermont, northern New Hampshire, and at Deer
island on the coast of Maine. The distribution of these rocks is
indicated on the accompanying map, plate II. The occurrence of
corundum in these regions is discussed further on, but it may be
stated here that, with two exceptions, it is not found with
olivine rocks north of Pennsylvania. The two localities excepted
are the emery deposits of Westchester county, New York, and the
corundum found at Pelham, Massachusetts.
(2.) IN NORTH CAROLINA.
The highest development of these magnesian rocks is attained in
North Carolina, where, in the southwestern connties, the outcrops
are thickly scattered over a region nearly forty miles in width. In
this region also — at Buck creek, in Clay county, and at Webster,
in Jackson county (see plates III and Y) — occur the two largest
dunite outcrops of the whole belt, covering areas of approximately
three-fourths and one-half a square mile respectively. It will be
seen, however, that the amount of corundum bears no relation to that
of the dunite ; for very little corundum has been found at Webster,
while the mine at Corundum Hill, (see plate IY) which has fur-
nished a steady output of corundum for seventeen years, covers an
area of only ten acres.
A more detailed description of localities is desirable in order to
point out local characteristics and variations in the rocks that
could not be represented on the map.
Along the southern boundary of the State, tliese rocks group
themselves roughly into three sub-belts, located approximately in
the valleys of the Chattooga, the Little Tennessee, and the Hi-
wassee rivers, though none of these retains its individuality for
any considerable distance. In Union county, Georgia, two and
a half miles south of the Towns county line, is the Track Rock
corundum mine. The magnesian rocks outcrop here chiefly in the
form of talcose chlorite schist. Little typical dunite is found,
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 35
though olivine grains are sometimes seen in the chlorite on the
fresh fracture, and an altered dunite was found here bj Mr. Francis
P. King, of the Geological Survey of Georgia. * This outcrop
is continued for two or three miles both north and south of the
gap, by talcose rocks; and northward the line is almost continu-
ous to the the Hamilton mine, which is located about a mile and a
half south of the North Carolina line. Near the road, about a
mile north of Young-Harris, is a small mass of forellenstein, and,
so far as observed, this is the only exception to the prevalent talc-
chlorite rocks of this line.
From this point, the line of outcrop drops back five miles to
the east, and appears again in normal dunite a mile and a half
north of Hiawassee. Here a long strip of laminated dunite crosses
the road and may be followed for more than half a mile; and, a
little further up Bell creek, two oval masses occur very near
together, with dimensions of 400 or 500 feet. Near this, on the
north slope of Bell knob, is a band of talc rocks interlaminated with
gneiss, and the talc is found in almost a continuous line to the
waters of Shooting creek in Clay county, North Carolina.
a. CIvAY COUNTY.
Here considerable chlorite is found, gradually passing into less
altered dunite near Shooting creek postoffice. After an interval
of two miles, this line is again found at the foot of Chunky Gal moun-
tain, composed of dunite and considerable schistose talc, in a strip
rarely attaining a width of forty feet, but continuous for three
miles across the mountain, and disappearing within a mile of the
great Buck creek area.
Three miles above the mouth of Shooting creek, in the vicinity
of Elf postoffice, are two other narrow strips of dunite very close
together and lying parallel in the lamination of the gneiss for
about a mile. Occasionally feldspathic phases are developed in
these rocks, and in one place a peculiar lamination is found where
feldspar and enstatite alternate with olivine in laminae of half an
inch to three inches in thickness. This lamination is almost at
^'Bulletin No. 2, Geological Survey of Georgia, p. 93.
36
CORUNDUM AND BASIC MAGNESIAN ROCKS.
right angles to that of the gneiss, and the whole is enclosed in
massive dunite. Accompanying the western strip almost its entire
length, is amphibolite, varying all the way from almost pure feld-
spar to pure hornblende rock. The latter is of a brilliant grass-
green, and sometimes bears beautiful red corundum. This strip
differs also from the other in being continued northeastward for
nearly three miles, by a narrow line of talc outcrops.
We now come to the Buck creek area, which is the largest
compact mass of peridotite in the State, and in fact, the largest
yet observed in the Appalachian belt. There is a greater surface
exposure in the vicinity of Webster, but it is drawn out into con-
siderable length, and in that respect differs markedly from that at
Buck creek.
The form and extent of this outcrop are shown in plate III,
which is reduced from a large-scale map made during the summer
of 1894. Points of especial interest, which will be dwelt on more
fully in a later report, are the amphibolite and forellenstein and
their relations to the dunite, the arms (apophyses) passing into the
surrounding gneiss, and the structure of the gneiss itself. In a
general way these points are shown in the accompanying map
(plate III) sufficiently well not to require further description here.
The area of this outcrop is approximately half a square mile.
b. MACON COUNTY.
The broad region over which the peridotites occur in this county,
as contrasted with the width elsewhere, especially northward,
would seem to indicate that considerable disturbance has taken
place here. Whatever theory may be adopted to account for the
origin of the peridotites, the conclusion that a number of parallel
breaks (fault-planes, or fissures) have been formed in this region is
one that is readily suggested by a study of the map (plate I). A
mile or two south of the State line, in Rabun county, Georgia,
small lenticular masses of dunite and enstatite rock are devel-
oped on Bettys creek. Much of this enstatite is quite fibrous and
abestiform.
On the road from Franklin, North Carolina, to Clayton, Georgia,
and almost on the State line, is an outcrop of dunite with consid-
N. C. GEOLOGICAL SURVEY.
BULLETIN 11, PLATE IV.
LEGEND:
Dunite
',',
Gneiss
(Showing directions of strike and dip.)
%M.
Mica-Schist
Corundum Workings
MAP OF
CORUNDUM HILL
Macon County, N.C.
r>u J. Volncij Lewis, 1B95.
Topography by Chas. E Cooke.
Contour Interval 10 feet.
SCALE OF FEET:
100 000 300
ESG'D PY AMERICAN cask NOTE CO.
FIGURES ON CONTOUR LINES GIVE ELEVATIONS ABOVE AN ARBITRARY BASE — THE FLAT ROCK BED OF THE BRANCH
NEAR THE SOUTHWESTERN CORNER OF THE MAP.
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 37
erable schistose talc ; and for fifteen miles down the Little Tennes-
see river, numerous small, often entirely isolated, outcrops are
scattered over the country. These arrange themselves approxi-
mately in lines and are represented on the map as continuous
masses, where, strictly, there should be a number of small dots.
Some of these are enstatite, and they are often represented on the
surface only by the talc that has resulted from their alteration.
Between the Cullasaja river and the Jackson county line, an
area on the spurs of the Cowee mountains is thickly dotted with
typical oval masses of normal dunite, of which the well-known
Corundum Hill outcrop may be taken as an example (plate IY).
Many of the masses are somewhat larger or different in shape from
this, but the variation is nowhere very great, and the same general
type prevails. Plate IY is a topograhic map of Corundum Hill,
and shows its most prominent characteristics. This rather blunt,
lens-shaped mass of dunite has an extent of about ten acres, and
the rock is laid bare over almost the entire surface. Enstatite,
which is developed at the south end of this outcrop, is not usually
found in the other places in this vicinity, though scattered grains
and nodules of it are quite common.
As indicated on the map, corundum is found over this entire area
between Walnut and Ellijay creeks, north of the Cullasaja, and
considerable activity is manifested in the search for workable
deposits.
C. JACKSON COUNTY.
In the line of strike of the gneisses of the Cullasaja region, are
found, in Jackson county, a series of long strips of chlorite schist,
as mentioned in the description of that rock, in the vicinity of the
forks of the Tuckaseegee river. Similar narrow bands of talc
schist are occasionally seen in the same region.
In some respects the dunite area at Webster (plate Y) is the
most remarkable outcrop of the whole Appalachian belt. In point
of shape it is entirely unique, bearing no resemblance, as a whole,
to the prevailing lenticular form. The line of outcrop traces an
almost unbroken ellipse, mostly northeast of Webster, with a major
axis of six miles lying north 25° east, and a minor axis of three
38
CORUNDUM AND BASIC MAGNESIAN ROCKS.
and a half miles. The width of exposure varies from a third of a
mile at Webster to extremely attenuated strips of talc in several
places ; and on the eastern side five complete breaks occur, the
smaller disconnected masses having the typical lenticular form.
Near its northern extremity, at Addie, an irregular mass projects
into the gneisses within the ellipse; and a little further west, a
gneiss area is entirely enclosed by slender strips of dunite and talc.
Near Sylva, on the western side of the area, for a short distance,
the deep soil covering rendered it impossible to determine whether
the belt is continuous or not ; and hence it is indicated there by a
dotted line on the map. Plate Y is reduced from a map of this
region which has been prepared for publication in the final report
on the corundum belt ; but the most prominent features alluded to
above are sufficiently well shown as not to require further explan-
ation.
Another important peculiarity of this Webster area is the high
development of lamination ; and this is best seen in the larger out-
crops about Webster and Addie. In its broadest portion, on the
hillside facing the river at Webster, is the type locality of web-
sterite, as mentioned in the description of that rock. It forms a
strip within the dunite about 300 feet wide in its greatest develop-
ment, and may be identified for a distance of about a mile. The
only other locality where I have seen this rock is on the eastern
side of this ellipse, about a mile above the mouth of Cane creek.
The peculiar form of the outcrop renders the structure of this
area unusually interesting. The strikes conform to the outline of
the ellipse, the dips, both inside and outside, are away from the
centre, and, in general, steeper as we go outward. The directions
of strike and dip are indicated by the symbols in the gneiss area,
near the borders of the dunite.
Near the head of Cane creek, and within half a mile of the
isolated dunite masses which form the eastern portion of the Web-
ster outcrop, another line of dunite and talc schists begins, which
is continued by a series of disconnected masses in a direction north
45° east almost to the Haywood county line, at Balsam gap. Near
the gap, a very coarse grained phase is developed, which bears
N. C. GEOLOGICAL SURVEY.
BULLETIN 11, PLATE V.
FIGURES ON CONTOUR LINES GIVE ELEVATIONS ABOVE SEA LEVEL
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 39
enstatite altered to talc, and good exposures are seen in railroad
cuts.
In the southern portion of Jackson county, several small danite
areas are found in the vicinity of Glenville, and associated with
these, talc and chlorite schists are developed in narrow belts. But
dunite is found in much greater abundance in the region about
Sapphire, including portions of both Jackson and Transylvania
counties.
Directly southwest of these outcrops and in the direction of trend
of the gneiss, is the Laurel creek corundum mine, in Rabun county,
Georgia. This mine is very similar in many respects to that at
Corundum Hill. The dunite outcrops in an oblong, somewhat
irregular mass, covering an area rather larger than that of Corun-
dum Hill ; and, so far as observed, no arms branch off into the
surrounding gneiss. The nature of the rocks is the same, though
a much larger development of enstatite is found. The principal
differences between these two mines are found in the minerals
developed with the corundum ; and further reference will be made
to these in describing the modes of occurrence of corundum.
Several small areas of dunite and talc rocks are found between
the State line and Sapphire, and quite a large area in the vicinity
of the latter place is thickly dotted with dunite and enstatite
rocks. Many of the smaller outcrops are necessarily merged into
each other on the map.
d. Transylvania county.
In the southwestern portion of the county, adjoining the Sap-
phire region of Jackson, the rocks are the same as those mentioned
above, but enstatite rook becomes more and more prevalent as we
pass northeastward into the valley of the upper French Broad
river. Often the surface exposures of this rock are entirely altered
to talc, and all the northwestern portion represented on the map
by the talc-chlorite symbol is composed of narrow strips of talc
schist, seldom exceeding twenty feet in width. Those nearer Bre-
vard are similar strips of chlorite, becoming quite talcose towards
the northeast. They are made up of several outcrops of "soap-
40
CORUNDUM AND BASIC MAGNESIAN ROCKS.
stone," as it is called, which could not be definitely connected by
search for intervening exposures ; but, on account of the small
scale, they have been thrown into continuous lines on the map.
e. HAYWOOD COUNTY.
From the crest of the Balsam mountains, the Haywood-Jackson
county line, a gap occurs in the peridotite belt, to the Pigeon
river above Clyde — a distance of 15 miles. Just north of the
river, scattering outcrops of soapstone occur over an area of sev-
eral square miles. But peridotite does not appear till we reach
the North Fork of Hominy creek, two and a half miles northeast
of Canton, the railroad station at the crossing of Pigeon river.
Here a strip of dunite several hundred feet wide and about half a
mile long crosses the road near the creek. Another small lens
occcurs near the head of the creek, and a strip of talc schist and
still another dunite outcrop is found in New Found gap. A mile
west of this line and on the waters of North Fork is the amphib-
olite outcrop in which is located the Presley corundum mine.
/. buncombe; county.
For a distance of seven miles from the county line at New Found
gap, the belt is not represented except for a small strip of talc
which extends for a short distance from the dunite at the gap.
Near Leicester, where the Asheville road crosses New Found creek,
another mass of dunite occurs with dimensions not exceeding thirty
by one hundred feet. A mile southeast of this, a small serpentine
outcrop about ten feet wide is found and, very near this another
serpentine mass about forty feet wide and about half a mile long.
Less than a mile further down New Found creek, two outcrops
are found about 150 feet apart — one a strip of serpentine ten feet
wide, and the other a typical dunite about thirty feet in width.
Both of these outcrops have been cut across in search of nickel
ore, and their nature is well shown. Decayed gneiss appears
between, and, as far as the outcrops show, the two masses have no
connection with each other.
^ti&f&aa
StaU £#pi
ar^t
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 41
For a distance of eight miles from this point, serpentine and
talc are the only basic magnesian rocks found. The belt crosses
the French Broad river a mile above Alexander — eight miles below
Asheville — in two narrow strips of serpentine that may be seen
north of the river on the Asheville road.
The river gorge here shows a fine section of the gneiss. It con-
tains many granitic and other igneous intrusions and its lamination
planes have been twis'ed and contorted in the most intricate man-
ner. Doubtless the forces which produced these phenomena have
had great influence in the hydration processes that produced the
serpentine and talc in the dunite belt through this region.
Through the Flat Creek mountains, only strips of talc and a little
serpentine are found, except one small outcrop of dunite five miles
from the French Broad river, near the head of Flat creek. The
talc outcrop is almost if not quite continuous to Morgan hill, two
miles south of the Madison county line. At this point, it connects
directly with a typical dunite mass which in a very short distance
attains a width of 400 to 500 feet, and is continuous with about
the same dimensions for three miles, ending with the Carter corun-
dum mine in Madison county.
This strip is remarkable for its size and the constancy of its
characters over so great a distance. Most of it is laminated, though
less so than that of Webster, and nickel and chrome stains are
quite prominent. Talc is highly developed along the borders, and
chalcedony is found in rather larger quantities than usual. Corun-
dum has attracted attention only in the northern portion of the
outcrop, beyond Ivy river; and important deposits have been found
only in the corner of Madison county, at the Carter mine.
The second parallel strip that was found at the crossing of the
French Broad river is still traceable in the narrow strip of talc
that appears at intervals from half a mile to a mile east of the
principal outcrop.
Q. MADISON COUNTY.
The Carter corundum mine is located in the north end of the
outcrop last described, which is continuous from Morgan hill, in
Buncombe county. Three miles north of this, serpentine again
42
CORUNDUM AND BASIC MAGNESIAN ROCKS.
appears on Paint Fork of Ivy river. Light green, massive rock
predominates, but some portions show a considerable amount of
unaltered olivine fragments visible to the naked eye. The outcrop
at the road is about 100 feet wide and is continuous for about
three miles toward Faint gap. At one point, a small mass of
unaltered dunite occurs about one-eigth of a mile east of the ser-
pentine, having a width of about fifty feet and interlaminated at
the borders with gneiss. This outcrop shows no tendency to the
development of massive serpentine.
The second and minor belt is represented in this county by dark
green serpentine on the head waters of Terrys Fork, about two
miles east of the main belt, in an outcrop about 200 feet wide.
Ten or twelve miles west of the principal peridotite belt just
described, is a zone of scattering soapstone outcrops, which crosses
the French Broad river two miles below Marshall. This zone
seems to have its beginning in a series of similar rocks found north
of Clyde, in Haywood county. In the southern part of Madison
county, soapstone occurs on the headwaters of Spring and Sandy
Mush creeks, and a number of outcrops are found along the course
of the latter within a few miles of its mouth. It appears then on
Little Pine creek, and on both sides of the French Broad river
below Marshall. Outcrops occur at intervals as we pass up Wal-
nut creek, and in a number of places on the waters of Big Laurel
creek, on the north side of the county.
The chief constituent of these outcrops is schistose talc with
more or less chlorite, the latter in a few places predominating, or
occurring almost pure. But one important exception was found to
this rule, and that is an outcrop two miles north of Marshall, on
Walnut creek, at the county poor-house. The rock here consists
largely of talc also ; but scattered thickly through it are grain: and
crystals of olivine, varying in size from a small fraction of an inch
to one or two inches in diameter. A rock exactly similar to this,
near Philadelphia, except that the olivine has largely altered to
serpentine, has been called "perido-steatite" Several of the soap-
stone outcrops in this Madison county zone are full of small "rust-
holes," as though similar olivine crystals had weathered out of it.
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 43
7l. YANCEY COUNTY.
Crossing the mountains about Paint gap, only talc schists repre-
sent the belt till near Cnney river the serpentine is again found on
Possum Trot (McElroys) and Bald creeks.
Here it has the same general characters as that on Paint Fork,
and the outcrops indicate masses of approximately the same dimen-
sions. Beyond Caney river, no direct extension of this line is
known, but two miles to the eastward, irregular outcrops of dunite
occur on the waters of Prices and Banks creeks, accompanied by
a little serpentine and a narrow strip of chlorite schist. Small
talc outcrops are also found on the Green mountains north of
Burnsville.
Four miles north of Burnsville, on Mine Fork of Jacks creek, a
very prominent lenticular mass of peridotite appears. It is about
half a mile long and 500 feet wide, and forms two small hills, one
on either side of the creek. The rock is normal harzburgite of
greenish yellow color, rather plentifully sprinkled with chromite
grains, and much of it contains talc scales of the form and appear-
ance of the original enstatite. A small peridotite mass occurs
half a mile north of this, and then the line of outcrop swerves sud-
denly eastward, just before reaching the Toe river. For the rest
of the distance within the county, it is represented only by narrow
talc strips and occasionally a little serpentine.
A still smaller belt appears to the east of this line of principal
outcrops, and this is seen in a narrow talc strip about two miles
northeast of Burnsville, and in a mass of dunite on Chestnut
mountain, four miles east of the locality on Mine Fork described
above.
This last locality is perhaps the purest type of olivine rock yet
observed in the whole belt. The outcrop is about 300 by 700 feet,
oval in shape, and forms a hill about 200 feet high, with a per-
fectly barren rocky surface except for occasional bunches of sedge
that grow in the crevices of the rocks. The longer axis of this
mass lies north 10° west. Besides light greenish yellow olivine, the
rock contains only a few disseminated scales of chlorite and, in
places, small flecks and interlacing veins of talc. The rock lias
44
CORUNDUM AND BASIC MAGNESIAX ROCKS.
weathered to a dull brown on the surface, but shows very little
alteration of any other kind. At the contact with the mica schist
in which it is enclosed there is a radial border of fibrous enstatite
altered mostly to talc, but such borders do not follow the joints
within the mass, as is often the case in other localities.
Ten miles west of Burnsville, in Egypt township, on the slopes
of Sampson and Bald mountains, occurs a strip of rocks that must
be considered as belonging here. At its southern extremity is
located the Hayes (or Egypt) corundum mine, and the predominant
rock is enstatite with a little dunite, the latter considerably altered
to tremolite. Three separate masses of enstatite rock occur at the
mine, and the line of outcrop is almost continuous across Bald
Mountain creek. From this point narrow talc strips were found
northward for a distance of four miles.
Again, on the eastern border of the county, we find a belt of
enstatite rocks, and talc resulting from their hydration, along the
valley of the South Toe river. Six miles south of the forks of Toe
river, corundum is found with one of these outcrops on Bailey
mountain. A mile east of this, there is a large outcrop of the
talc-olivine rock ("perido-steatite") described above (see Madison
county). The olivine crystals in this case are, however, much
larger, some of them being several inches in diameter.
I. MITCHEI.I, COUNTY.
Eight miles south of Bakers ville, and just north of the ford of
South Toe river, is an outcrop about one-fourth of a mile long and
300 to 400 feet wide, composed chiefly of dunite, though there is
also considerable enstatite rock ; and forming the transition
between these two types, harzburgite is developed. This locality
is very similar to that at the Woody place described next below.
Two and a half miles south of Bakersville is a large lenticular
outcrop of dunite on what is known as the Woody place. It is
about 300 by 600 feet and the long axis lies north 65° east. It is
a light green dunite with considerable masses of enstatite rock.
Very little chromite was seen. Cellular and compact chalcedony
and nickel stains are abundant. The hillside which is composed of
this rock is quite barren and rocky.
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 45
From this place a line of enstatite and talc rocks, outcropping at
frequent intervals, extends up Cane creek. One small dunite
mass appears near the summit of Grassy Ridge Bald, considerably
to the north of the general line; but the original direction is con-
tinued by the large outcrops on North Toe river, six miles south
of Cranberry, near the mouth of Roaring creek. This is a large,
irregular area which is continuous for nearly a mile with a width
of 150 to 200 feet,
Considerable chromite is found in some portions of the rock,
and chrysotile (fibrous serpentine, commonly called asbestos) is
highly developed at the north end of the exposure, just below the
mouth of Squirrel creek. Another area of dunite occurs near this,
on the side of Haw mountain.
At Bellevue, on the summit of Fork mountain, two miles south
of Cranberry, dunite also appears in an outcrop abolit 200 feet
wide and greatly altered to serpentine and talc. The outcrop can
be traced by a strip of the latter for about one-fourth of a mile.
But here we evidently encounter the results of very great and com-
plex earth movements, as shown by the manner in which the rocks
of the Ocoee formation have sufferen folding, crumpling and gen-
eral breaking up ; and also by the presence of considerable bodies
of massive rocks. In this region of intense confusion, no recogniz-
able peridotites or related rocks have been observed for a distance
of about sixteen miles from the outcrop at Bellevue mentioned
above.
j. WATAUGA COUNTY.
Normal conditions are somewhat restored in the upturned edges
of the gneisses on the western side of Rich mountain, just north of
Boone. The first appearance of peridotite is observed in the road
about two and a half miles west of Boone, where atypical yellow-
ish dunite appears in a small outcrop. From this point outcrops
occur at intervals in a curved line following the general trend of
the mountain for a distance of four miles northward. More or less
talc and asbestos accompany these occurences.
Near where the road crosses the mountain at the northern
extremity of this line, a considerable body of chromite has been
46
CORUNDUM AND BASIC MAGNESIAN ROCKS.
removed in prospecting. It was in the form of a lenticular mass
lying in the pure olivine rock, narrowing within a few feet of the
surface to a small vein. These places constitute the last dunite
outcrops found on the belt within the State. Further northward,
enstatite becomes a predominating element, as in the region about
Sapphire, in Jackson county, and in a number of cases constitutes
the whole mass of the rock.
Just east of the northern extremity of this Eich mountain dunite,
and about four miles north of Boone, an enstatite rock is encoun-
tered— in places altered into talc on the surface — forming,
in some cases, masses of a hundred feet or more in width and
traceable across the country continuously for about two miles.
Other areas of less importance are indicated on the map, but it is
scarcely necessary to mention them all in detail.
Of the other areas indicated on the map, one six miles east of
Boone, on the crest of the Blue Ridge just north of Cook gap, is
worthy of mention. Talc, bearing fine radiating actinolite, is the
predominant rock in an outcrop about fifty feet wide and, per-
haps, three or four times as long. But there are also large masses
of dark green serpentine, the only occurrence of this rock that I
have found north of Cranberry. About one-fourth of a mile north-
east of this, another outcrop of soapstone of about the same dimen-
sions is found on the estern slope of the Blue Hidge.
k. ASHE COUNTY.
An outcrop of importance, both on account of its unusual size
and the type of rock represented, is found on the middle fork of
Elk creek three miles from its mouth, and situated just east of the
Watauga county line. Here an immense mass of harzburgite, the
olivine-enstatite peridotite, forms heavy cliffs on the western
slope of Black mountain, and great quantities of it have rolled
down into the creek below. The rock consists of about equal
parts of enstatite and olivine, and the texture varies from a uni-
form fine grain to that in which both constituents assume dimen-
sions of three or four inches. Blocks of scaly chlorite, bearing
red garnets one-fourth of an inch in diameter and occasional crys-
tals of magnetite, are also found.
DISTRIBUTION OF PERIDOTITES AND ASSOCIATED ROCKS. 47
Four miles northeast of the outcrop just described, is another
great mass of harzburgite, on Bee Ridge, a short spur on the east
side of Elk Ridge. The mass is about a thousand feet wide, length
undetermined, and presents a forked outline at the south end.
Enstatite frequently predominates, and soapstone derived from it
constitutes about half of the outcrop. This is sometimes schis-
tose, though it often retains the structure of the mineral from
which it is derived. Considerable quantities of this stone have
been used for furnace linings in the copper works at Ore Knob.
In the surrounding country, most of the fireplaces and many of
the chimneys are built of it ; and it is found quite suitable
for these purposes, both on account of its fireproof qualities and
the ease with which it is worked. Soapstone outcrops have been
worked at intervals, along the flanks of Elk Ridge, for three or
four miles north of this place.
Other small outcrops of soapstone, which have had some local
application, are found on Negro mountain, just south of Jefferson,
and one and a half miles north of Jefferson, at Phoenix gap.
I. AUEGHANY COUNTY.
The first appearance of peridotite in this county is found three
miles south of Sparta, near Little river, where soapstone is found
in the road to Whitehead. From this point, a line of disconnected
harzburgite outcrops follows the general direction of Little river
almost to the Virginia line. It is typically developed about a
mile east of the mouth of Pine Swamp creek, also just north of
the mouth of Glade creek, in the great bend of the river, and
south of the river, at the mouth of Brush creek. It next appears
at Ennis, on Crab creek, and is found in almost a continuous line
up the north fork of this creek, in a direction about north 50°
east, to the Virginia line. The same rock is said to occur almost
continuously for fifteen miles further in the same direction.
This rock has about the same nature as that at Bee Ridge, in
Ashe county, described above. All stages are found between pure
talc and nearly pure olivine rock, but the latter is never quite
free from a certain perceptible amount of talc or enstatite. A
coarse lamination is generally discernible, and the purer steatite
/
48
CORUNDUM AND BASIC MAGNESIAN ROCKS.
portions are usually schistose. The latter also frequently bears a
considerable proportion of carbonates; and the numerous "rust-
holes" in some portions of the outcrops are doubtless due to the
weathering out of these minerals and olivine.
6. CORUNDUM.
For a complete description of the chemical, physical, and crys-
tal lographic characters of corundum, the reader is referred to
Dana's System of Mineralogy, or to any good text-book on the
subject. Only the most important features are related here, and
technicalities, while not entirely avoidable, are dispensed with or
explained as far as practicable, for the benefit of the general
reader.
(1.) CHARACTER AND VARIETIES.
Next to diamond, corundum is the hardest substance known in
nature, and on this property, as more or less modified by other
qualities named below, depends its commercial value. It crystal-
lizes in the rhombohedral division of the hexagonal system ; but
the six-sided prism is usually the most prominent form, and the
crystals often appear to have the complete hexagonal symmetry
(see figures 1, 2 and 3). Sometimes, however, the rhombohedron is
quite prominent, but it is usually developed only in small faces
truncating the alternate corners of the prism and basal plane or
pyramid.
Small crystals are usually quite perfectly formed, but the
larger ones are generally rough and irregular, with many of the
faces deeply corrugated. Figures 1 and 2 show the hexagonal
form as effected by rhombohedral and basal parting, respectively.
Figure 3 is a crystal with rhombohedral parting well shown by
the faces it has produced on the prism. Figure 8 is a common
form of wrapped crystal.
Strictly speaking, corundum has no cleavage, but two forms of
parting, often erroneously called cleavage, are frequently met
with. This parting is due to multiple twinning, and the form
CORUNDUM CHARACTER AND VARIETIES.
49
most commonly seen is that parallel to the rhombohedral faces,
which are inclined to each other at an angle of 93° 56r, thus
breaking the crystal into almost cubical blocks, (see figures 1, 3, and
7). The other form of parting is parallel to the basal plane, and
crystals in which it is developed break square across into a number
of thin segments, often resembling buttons, (figure 2). Crystals
or masses in which no parting is developed break with a rough,
uneven fracture.
Fig. 1.
Fit
Fh
Fig. 1.— Hexagonal crystal of corundum showing rhombohedral parting. (From
Tschermak's Mineralogy.)
Fig. 2,— Corundum crystal showing basal parting and concentric zonal arrangement of
colors. (Tschermak.)
Fig 3.— Corundum crystal from Egypt mine, Yancey county, showing hexagon termi-
nated by rhombohedral parting planes. One-fourth natural size. (Drawn from a photo-
graph.)
Corundum sometimes appears in masses without crystal form,
though crystalline in structure, and such masses may have either
form of parting described above. Crystalline granular aggregates
are also sometimes met with.
All the foregoing varieties of form and crystallization are
subject to great variation in color — gray, blue and red being the
most common. Corundum is usually more or less translucent, but
seldom transparent. The more strongly colored varieties are
pleochroic; that is, they show different colors for light passing-
through them in different directions.
Corundum has a specific gravity of 3.9 to 4.1, which is equiva-
lent to saying that it is about four times as heavy as water. Of the
minerals associated with it, only chromite and magnetite are
heavier, garnet and spinel are about the same weight; olivine,
50
CORUNDUM AND BASIC MAGNESIAN BOOKS.
chlorite, hornblende, tourmaline and margarite are not so heavy;
while quarty, feldspar, serpentine, and talc are much lighter.
Professor Dana, in his description of the varieties of corundum,
says : "There are three subdivisions of the species prominently
recognized in the arts, and until early in this century regarded as
distinct species ; but which actually difTer only in purity and state
of crystallization or structure."*
The three varieties mentioned are ; 1. Sapphire, 2. Corundum,
3. Emery.
1. Sapphire includes all those transparent and translucent kinds
which are of good colors and useful as gems. Jewelers designate
the various gems according to colors : the red is the oriental or
true ruby ; the blue is the sapphire; the yellow is the oriental
topaz ; the green is the oriental emerald / the purple, the oriental
amethyst ; and the opalescent variety showing a six-rayed star of
light is called asteria, or star sapphire. North Carolina has pro-
duced the sapphire variety of corundum in every known color.
2. Corundum, as the term is used in the arts, " includes the
kinds of dark or dull colors and not transparent, colors light blue
to gray, brown and black." This is the rough material which
forms the bulk of the product of the North Carolina mines.
3. Emery is an intimate mixture of granular corundum and
magnetite or hematite. This is the form of much the greater part
of the corundum used in the arts ; a fact which is due to its com-
parative abundance and cheapness in Asia Minor and the Grecian
Islands, while corundum is obtainable only in much smaller quan-
tities and at greater expense. Emery is mined at Chester,
Massachusetts, and has been obtained in small amounts from
Westchester county, New York. It was found in Guilford county,
North Carolina, in 1871, by Dr. Genth, (see index reference,
.Emery), and has been recently reported from a locality in Macon
county, North Carolina, but, so far as I am aware the material has
not yet been examined, so no further statement can be made in
regard to it at present.
'Dana's System of Mineralogy, 1892, page 212.
j*}iai9 %j/{hi»&?2»
USES OF CORUNDUM. 51
(2.) USES OF CORUNDUM.
The use of the sapphire variety for gems has already been
pointed out in the description above. The red colors are most
highly prized for this purpose, and especially that particular
shade known as "pigeon-blood." Fine specimens of two or three
carats in weight are equal in value to- the diamond.
Corundum and emery are used for the same purposes, and in
both the value is due to the hardness as applied to cutting and
polishing metals, glass, stone, and all hard substances. The mate-
rial to be used for polishing is first crushed and then sorted
according to size of grain by passing through sieves. For most
cutting and grinding purposes, the granular material thus obtained
is made into a kind of dough with some cementing material, then
moulded into the form of a grindstone and baked. Such artificial
stones are called corundum wheels or emery wheels, according to
the material of which they are made, and are extensively used in
all kinds of metal working, especially the iron and steel industries.
(3.) NORTH CAROLINA CORUNDUM.
The gem varieties of corundum were the chief attraction for
the early prospectors and miners. The mine at Corundum Hill,
in Macon county, the story of which constitutes the greater part
of the history of corundum mining in the United States, was
opened and worked for a number of years as a gem mine. Some
of the material that came from this mine and other localities in
the State has attracted considerable attention, as may be seen from
the following mention by Mr. George F. Kunz :
"In variety of color the North Carolina corundum excels. It is
found gray, green, rose, ruby-red, emerald-green, sapphire-blue,
dark blue, violet, brown, yellow, and of intervening shades, and
colorless" "Many specimens [from North Carolina] have been
cut and mounted, especially of the blue and red shades, and make
good gems, though not of the choicest quality. Several rubies of
1 carat each have been found ; a blue sapphire, 1 carat in weight,
/
52
CORUNDUM AND BASIC MAGNESIAN BOCKS.
is in the United States National Museum at Washington, and a
series of fine red and bine crystals has been deposited there by
Dr. H. S. Lucas."*
In several localities, as on Ellijay creek, in Macon county, crys-
tals of a peculiar brown corundum with a beautiful chatoyant
lustre have been found. "These (when cut en cabochon) all show
a slight bronze play of light, and under artificial light they show
well defined stars, being really asterias, or star-sapphires, and not
cat's eyes, as might seem at first sight to be the case."f
Although the principal work in the mining region is now con-
centrated on the search for commercial corundum, still there is a
considerable interest shown in some sections in prospecting for
gems; and Mr. Kunz writes again in 1893: "The finding of small
rubies of fairly good color in Macon county, North Carolina, gives
ground for the belief that larger and better stones may be found
there by more extended development."^: •
Commercial corundum does not occur in all the varieties of color
that are found in the gems, but there are differences of texture and
purity that have no less important bearing on the value of the pro-
duct than color and transparency in the gems. As mentioned
above in describing the varieties, this class includes all those dull and
dark colored kinds which constitute the priucipal product of the
mines. The colors are generally gray, or some shade of blue, or mot-
tled white and blue; but the variations in texture are much more
important than those of color. The different mines of the State
produce every known variety : massive or "block" corundum, crys-
tal corundum, and the fine granular or crystalline variety called
"sand" corundum. And all these are sometimes found associated
in the same immediate locality or even the same mine. Each
mine has its own peculiar characteristics, however, and a kind of
family resemblance runs through its whole product. This fact is
well recognized by the miners, and they can frequently ascribe a
specimen to its proper locality by its general appearance.
Corundum from some localities is chiefly six sided crystals, often
*George F. Kunz, Mineral Besources of the United States, 1892, pages 760, 761.
tGeorge F. Kunz, Gems and Precious Stones of North America, 1890, page 47.
^George F. Kunz, Mineral Besources of the United States, 1893, page 680.
NORTH CAROLINA CORUNDUM. 53
tapering toward the end like a barrel — hence, we sometimes hear the
term "barrel corundum" — and these crystals may or may not
have one of the forms of parting developed. If parting is absent
or only developed to a slight extent, the crushed product will be
solid and tough, even in the coarser numbers; while, if it is very
highly developed, the coarse numbers and sometimes also the
medium and finer sizes will be full of these parting planes along
which it will easily crumble down in use. Besides producing a
defective grain, there is always considerable loss in crushing from
the production of an unusual amount of "flour."
The massive or "block" corundum may have the same defects,
though this is usually not the case, and hence such material, when
in sizes suitable for crushing, produces a good tough grain. But
the difficulty encountered in working such corundum lies in the
size of the masses, which are frequently intergrown with feldspar
and hornblende into blocks so tough that they cannot be profitably
broken and crushed. This is the case with some of the material
mined at Buck creek, in Clay county. This variety is also found
in veins of tough, compact materials which render its removal from
the mine a source of considerable expense.
Sand corundum consists of small crystals and irregular grains,
which are developed in the soft vermiculites surrounding the
peridotites, and hence are always easily dug out and the corundum
obtained by washing away the lighter minerals. This variety is
not subject to the difficulties and defects of the other two, but, as
there is considerable variation in the size of the grains, it is impos-
sible to remove all the lighter minerals by washing, and, of course,
the magnetite and chromite cannot be thus removed.
Corundum in place in the rocks is subject to numerous altera-
tions by which its hardness is impaired even in incipient stages ;
and this property is entirely lost in the complete alteration,
which produces a series of aluminous minerals of little or no value
as abrasives.
It is a well known fact that chemical action takes place much more
rapidly on small grains than on large ones, owing to the greatly
increased proportion of surface exposed: hence, sand corundum is
more subject to alteration than the larger masses. The sand may
51 CORUNDUM AND BASIC MAGNESIAS' ROCKS.
be in some cases only the remnants of larger masses which have
disappeared through this means. Still, sand corundum is the kind
most sought by the miners, and the usnal presence of more or less
crystal corundum along with it makes up to a certain extent for
its lack of purity. These two forms constitute the product of the
mine at Corundum Hill.
(4.) MODES OF OCCURRENCE OF CORUNDUM.
Professor Zirkel enumerates the following modes of occurrence
of corundum as a rock constituent'. Corundum in small, fine
grained aggregates is the chief constituent of emery. Otherwise, it
occurs only occasionally as an accessory in granites, gneisses, granu-
lar limestones and dolomites, in the amphibolites of northwestern
Austrian Silesia (largest hazel-nut size, white or blue grains i,
in the cholorite schist of Nischne-Issetsk in the Urals, in the graph-
ite of Miihldorf, near Spitz, in Lower Austria ; as blue sapphire
in several basalts, where it is perhaps originally a remnant of mol-
ten inclusion; often with spinel, rutile and sillimanite. Worthy
of note is the occurrence as a contact product of the diorites of
Klausen, in Tyrol. It is also observed as altered foreign inclu-
sions or as real accessory masses in certain eruptive rocks, often
with cordierite, spinel, andalusite — as inclusions in the andesite
of the Eifel, and similarly in tonalite. Further it appears scattered
through a contact product of qnartz-mica-diorite on quartz-phyl-
lite in Yal Moja. Similarly in the kersantite of Mickaelstein,
Harz.*
Besides these occurrences as a rock constituent, corundum is
found in large quantities in feldspar veins and associated with clilo-
rites in the peridodtites and serpentines of the Atlantic States
of America ; and in areas of crystalline rocks in many parts of the
earth's surface, in the gravel-beds of streams. Except the occur-
rences in granular limestone, in graphite, and in association with
volcanic rocks, all the various modes enumerated above have been
observed in North Carolina. These will be described briefly in the
following order:
*F. Zirkel, Lehrbuch der Petrograptiie, Leipsic, 1893, page 416.
CORUNDUM ASSOCIATED WITH PERIDOTITES. 55
a. Associated with peridotites ; h. In chlorite schist ; c. In
amphibolite ; d. In dunite ; e. In gneiss ; f. In gravel deposits.
a. CORUNDUM ASSOCIATED WITH PERIDOTITES.
The occurence of corundum in the State, with few important
exceptions, is in association with olivine rocks (peridotites), though
rarely occurring in the body of such rocks. It is found in the
zone of chlorites and vermicnlites developed between the perido-
tites and the gneisses of the surrounding country, and sometimes
near this zone in the gneisses themselves. In some cases this
border zone of chloritic minerals carrying corundum has de-
veloped along -the joints of the peridotites to the very center of
the mass. Such a condition is shown in a number of openings at
.Corundum Hill, though mining operations have been chiefly con-
fined to the border zones. (See figure 6.)
These zones vary exceedingly in thickness, from ten or twelve
inches to as many feet, and the proportion of corundum is scarcely
more constant, though bearing no relation to the dimensions of
the "vein". In places the chlorites are thickly studded with cor-
undum almost from wall to wall, and sometimes this condition
prevails for a considerable distance; then the corundum-bearing
portion wTill narrow down to a thin strip in the middle, or perhaps
disappear entirely, to be encountered again only after a consider-
able amount of barren material has been handled.
There is a prevailing impression that peridotite always occurs
in hornblende-gniess. While this is frequently the case it is by
no means universally true, as a microscopic examination shows some
of these enclosing rocks to be normal gneiss ; that is, composed
of quartz, feldspar and mica (the mica being chiefly biotite). In
other cases, the country rock is mica-schist.
A gneissoid rock resulting from the lamination of the bright
green hornblende rock found at Buck creek, in Clay county, and
elsewhere, is closely associated with the' peridotites of these local-
ities; but it is here regarded as a member of the peridotite group,
and is not classed with the country rocks.
The gneiss of this region, wherever found in contact with the
56 CORUNDUM AND BASIC MAGNESIAN ROCKS.
peridotites near the surface is considerably decomposed, crumbling
easily into a loose sand, though retaining a fresh appearance and
the original structure of the unchanged rock so far as may be seen
with the unaided eye.
In the description of the secondary products found in connection
with the alteration of dunite, mention was made of the enstatite
casing which often surrounds the jointed masses of the rock. In
most cases, it is quite clear that these casings are closely connected
with the chloritic zones that bear corundum. They are composed
of enstatite, often fibrous and usually altered more or less to talc :
and the structure is radial, or parallel, the fibres standing normal
to the outer surface of the dunite block enclosed. In all cases
observed, the enclosed rock is more or less altered, and frequently
to such an extent that only a soft ochreous, clay-like mass remains,
though the casing may be tough and apparently fresh. These
casings often contain more or less chlorite, and especially towards
their outer portions; furthermore, they are never developed ex-
cept in places where chlorite is also formed along the borders and
more prominent joints of the peridotites; and, vice versa, some
slight development, at least, of such enstatite always lies between
the chlorite and the olivine rocks.
The whole zone, consisting of chlorite, vermicnlite, talc, and the
enstatite border is frequently sheared until all original structure
is replaced by a high development of schistosity.
A number of other minerals are always present in minor pro-
portions, varying in importance in the different localities. Some
variety of amphibole, pyroxene, spinel, and tourmaline are fre-
quently observed; staurolite, diaspore, and anthophylliteare occa-
sionally seen ; and, where the corundum is associated with feld-
spar, margarite and zoisite are frequent accompaniments. Muscov-
ite, margarite, and other minerals that so often form the wrapping of
corundum crystals, appear to be in many cases undoubtedly the
results of alteration of that mineral, as indicated by the researches
of Dr. F. A. Genth.
The green and yellow micaceous minerals, known respectively as
chlorite and vermiculite, have been divided into several more or less
OOKUNDUM IN CHLORITE SCAIST.
57
definite species based on chemical analyses. Lucasite, kerrite,
culsageeite, jefferisite, wilcoxite, etc., are some of the names
that have been given to the yellow and brownish minerals ; but
the distinctions are almost purely chemical, and the names are of
no practical value in the held examinations; and, in most cases,
their use would tend only to confusion. These are all grouped
here under the name vermiculite. Pennine, clinochlor, prochlor-
ite, cornndophilite, etc., are some of the more important subdivi-
sions of the chlorite group ; but the same condition exists here as
in the vermiculite group, so far as field distinctins are concerned,
and the term chlorite is used for all green colored micaceous
minerals associated with corundum and the olivine rocks. *
In the midst of these Chlorite zones, corundum is sometimes
found in veins of feldspar, as at Buck creek, and with amphibole
rocks in Iredell county. In rare cases quartz is intergrown with
the feldspar, forming a true pegmatite. Such a vein, without cor-
undum is found at the Hamlin prospecting, on the head-waters of
Ellijay creek, in Macon county.
b. CORUNDUM IN CHLORITE SCHIST.
An occurrence in some respects similar to that in the chloritic
zones about peridotites, is found in the long belts of chlorite schist
that traverse the country ten to twelve miles southeast of Webster.
Chloritic rocks here, which sometimes attain a width of several
hundred feet are traceable across the country for several
miles. Green, scaly chlorite is almost the only constituent of
these rocks, though sometimes they are flecked with small white
grains of feldspar, and occasionly amphibole needles are seen.
The chlorite is in small scales, never very coarse, as is sometimes
the case in the zones about peridotite, and often they are so min-
ute as to impart quite a compact appearance to the rock.
In one of these belts, on Caney Fork of Tuckaseegee river, cor-
undum is disseminated through the chlorite in small rounded
masses, ranging from an inch in diameter to minute grains. In
*A careful investigation of the chemical and mineralogic relations of corundum and
its associated minerals is now being pursued by Mr. Joseph H. Pratt, of Yale University
and the most of these minerals are here referred to only in a general way.
5S CORUXDCM AXD BASIC MAGNESIAS BOCKS.
these cases, the chlorite is not so tough and compact as elsewhere,
and the corundum is invariably wrapped in a coating of white
mica, usually in radiating scales perpendicular to the outer sur-
face of the corundum. The mica coating is exceedingly thin in
some cases, but it is so variable that many nodules are composed
almost entirely of it with only a small grain of corundum in the
centre. The secondary nature of this mica and its derivation from
the corundum can scarcely be doubted.
C. CORUNDUM IX AMPHIBOLITE.
The beautiful grass-green hornblende rock, which forms impor-
tant dike-like masses at various peridotite localities iD Clay county,
was described above among the massive rocks associated with per-
idotite (p. 28). Besides the green hornblende and the an orth.it e
which constitute the principal constituents of the rock, there is
always present, in the corundum-bearing phase, microscopic grains
of picotite, and the smaller grains of corundum are usually inter-
grown with irregular masses of this mineral and enclose many
minute particles of it.
The corundum ranges in size from the minute microscopic
grains to large masses of several inches in width, and is usually
laminated or possesses a parting according to the rhombohedron,
which breaks it into small, nearly cubical blocks. It ranges in
color, too, from almost white to deep ruby-red. most of it being of
quite a decided red color. Some portions of the rock are thickly
studded with corundum, and boulders of this kind have been
gathered from the surface at Buck creek and hauled on wagons to
Corundum Hill to be crushed for separation. It has furnished
some handsome cabinet specimems, the contrast of the bright red
and green colors producing a striking effect ; but it is an exceed-
ingly tough rock and is not likely soon to become a commercial
source of corundum.
The corundum that has been found in place in the vicinity of
Statesville, Iredell county, is developed in the joint-planes and
along the borders of coarse hornblende rocks, much in the same
manner as that with dunite at Corundum Hill and elsewhere in
the more westerly counties. These hornblende rocks appear in
CORUNDUM IN AMPHIBOLITE.
59
the gneisses somewhat as the peridotites, so far as may be judged
from the meagre outcroppings available, and the corundum is
found with fine brown, scaly vermiculite, which is developed in
zones from a few inches to three or four feet in thickness, along
the borders, and through irregular joints in the hornblende rock
(See figure 4). In one or two instances, feldspar veins five or six
inches thick, sometimes altered to kaolin, were observed in the
midst of the vermiculite zones. This feldspar often bears corundum
also, though in prospecting most of it was found with the vermi-
culite. The corundum is in crystals and rounded masses of crys-
tals clustered together; sometimes margarite accompanies it, and
large masses have been found on the surface in this region made
up of these two minerals.
Fig. 4.
Fig. 4. Diagram illustrating the mode of occurrence of corundum in amphibolite at
Hunter's, seven miles west of Sfcaiezviile, Iredtdl councy. a, Feldspar vein, (not always
present) sometimes carrying corundum; b, Fine scaly vermiculite with crystals and
lumps of corundum; o, Radiating uorder of actinolite enclosing large blocks of (d) dark
green hornblende rock.
Still another point of similarity to the occurrences in connection
with peridotite is found in the radiating borders that intervene
between the corundum-bearing vermiculite z.ones and the massive
rock. In this case, the radiating border is composed of a green
horneblende similar to actinolite, instead of the enstatite. Sim-
ilarly, the rounded blocks thus inclosed are often almost completely
decomposed ; so that we find, on breaking through this radial
60
CORUNDUM AND BASIC MAGNESIAN ROCKS.
casing, only a mass of ochreons clay b( aring occasional needles
of horneblende and scales of brown vermiculite.
d. CORUNDUM IN DUNITE.
Thus far I have observed but one instance of this association;
and, so far as I am aware, it is entirely unique. This was found
at the Egypt mine on the western slopes of the Sampson moun-
tains, in Yancey county, by Mr. U. S. Hayes, who was prospect-
ing at the time of my visit. I am indebted to him for two of the
best specimems collected, one of which is shown in figure 5. It
consists of a hexagonal crystal of corundum completely surrounded
by granular dunite, with none of the chloritic minerals which
usally intervene. The dunite is not quite fresh, being stained
yellowish brown and rather friable. A little muscovite is devel-
oped along the basal parting planes of the corundum, as is often
the case in other occurrences.
Fig. 5.
Fig. 5. Corundum crystal in altered d unite. From Egypt (Hayes) mine, Yancey countv.
One-half natural size. (Drawn from a photograph.)
With one possible exception, so far as I am aware, this is the
first instance of such anomolous mineral association yet recorded.
In enumerating the minerals of the Buck creek corundum locality,
in 1875, the late Dr. C. D. Smith states that he found "chrysolite
attached as an enveloping matter to considerable masses of cor-
undum ;" * but as neither Dr. Smith nor any of the numerous
writers on this subject during the succeeding twenty years have
made any further mention of this extraordinay discovery, it may
*Report of the North Carolina Geological Survey, 1875, Appendix page 95,
CORUNDUM IN GNEISS.
61
be fairly assumed, I think, that this passage refers only to the
ordinary occurrence of corundum in the chlorite zones developed
within the peridotite and along its borders.
e. CORUNDUM IN GNEISS.
In the same belt of crystalline rocks that carries the peridotite,
but apparently, in no way connected with the latter, corundum is
found in a number of localities in the ordinary gneiss of the coun-
try. Five years ago Dr. Genth * described, as a new mode of
occurrence for corundum, that discovered in the mica schist region
of Patrick county, Virginia. The schists are sometimes garnet-
iferous and gn eissic, and the corundum is associated with andalu-
site, cyanite, chloritoid, mica, etc. The schists were intersected
with granite dikes, and the corundum was found near these in
crystals and rounded masses on the surface.
In the North Carolina localities, corundum occurs in place in
the gneiss in nodules of half an inch in diameter and smaller, and
wrapped in a sheath of radiating muscbvite, similar to that in the
chlorite schist described above. None of the accompanying min-
erals described by Dr. Genth were observed, and but for the pre-
sence of these nodules, the lock seemed to be in every way normal
gneiss. The nodules, on account of their resistance to the decom-
posing forces of the atmosphere, always stand out prominently on
the weathered surface; and they are often present in such propor-
tion as to thickly stud these surfaces with little white and grayish
knots.
In one instance, however, the corundum-bearing gneiss is asso-
ciated with basic magnesian rocks, though such has not yet been
shown to be the case in other instances. The basic rock referred
to here occurs on the head waters of Shooting creek, in Clay county,
and consist largely of fine grained green horneblende and hypers-
thene — the latter somewhat predominating. The sections of this
rock have not been sufficiently studied to determine whether the
horneblende is primary or secondary, but the preponderence of the
hypersthene would give ground for calliing it hypersthenite. This
rock cuts through the gneiss in two dikes about ten feet thick
*F. A. Genth, Am. Jour. Science, 3, xxxix, 1890, pa^es 47, 48.
62 CORUNDUM AND BASIC MAGNESIAN ROCKS.
t
and about 500 or 600 feet apart. The Corundum is found in
the gneiss between, intimately associated with a small pegmatite
vein and a band of very black mica.
Just beside one of the dikes also, corundum was found in a zone
of line scaly brown mica. This corundum is in nodules and, like
that in the gneiss betweeu the dikes, has two systems of parting
well developed.
In other localities, no such relation to magnesian rocks has been
observed. The covering of soil and decomposed rock is, however,
very deep in some places, and quite sufficient throughout most of
this region to render the outcrops rather obscure.
On the western side of Chunky Gal mountain, bands of brown
mica, bearing lumps of granular garnet, and both carrying more or
less corundum, are found in the gneiss. So far as determinable at
the time of my visit, the corundum here has no connection with
peridotite or similar rocks.
/. CORUNDUM IN GRAVEL DEPOSITS.
It is well known that the gem varieties of corundum are found
chiefly in the soil and gravel beds of Burma, Ceylon, and other
regions of southern Asia. Along with these, the common forms
of crystalized corundum are also found ; and, in some of the local-
ities, the mineral has been traced to its origin in the crystalline
rocks.
The gravel beds represent the result of ages of concentration.
While the rocks have been slowly decomposing and crumbling
away through the agencies of air and water, the stream beds fur-
nished a natural system of sluices in which the heavy and more
resistant minerals, including corundum, have been caught and
retained, while the lighter material has been carried out to the
sea. Hence, although the corundum gems may have been quite
rare in the original rock, they are found in these gravel deposits
in cotriparitive abundance ; and even when the original source is
found, the gravels still remain the principal commercial source.
Most of the corundum localities of North Carolina have beeu
found through the discovery of fragments in the soil or in beds of
streams; and it is a favorite method with prospectors to wash the
.
distribution' of corundum. 63
gravels of stream beds for corundum, much in the same manner as
search is made for gold. Similarly, corundum crystals have been
ploughed up in bottom lands, and further investigation has revealed
gravel beds, often of considerable extent, which usually bear sev-
eral varieties of corundum. Search up the stream and its tribu-
taries till no further trace is found and then up the adjoining
hillsides, has in many instances brought to light the source of
these valley deposits ; but, in a number of cases, such search has
proven, thus far, fruitless; and we are led to the conclusion that
the corundum must have been concentrated from rocks in which
it is only a rare constituent.
Several such deposits, in Macon and Jackson counties, have fur-
nished ruby-colored corundum of nearly every shade, and consider-
able attention has been devoted to the search for gems. Occasion-
ally pieces are found sufficiently transparent and free from flaws
to be cut into fair gems, though most of it is too much clouded
and the parting too highly developed to be of any value except as
mineral specimems. The principal object of the recent work
in these gravels has been to locate the original source of the
material in the hope that the finer specimens may be found in
sufficient quantity to establish gem mining on a profitable basis.
Small grains and crystals of corundum are found in the gold
placers of Rutherford, McDowell and Burke counties, 'but they
are not considered of sufficient importance to be indicated on the
map.
(5.) DISTRIBUTION OF CORUNDUM.
As indicated above, in the description of the modes of occurence,
the home of corundum is in thet highly crystalline rocks, and
chiefly in the region of gneisses. This is true of all occurrences
that attain to any but purely scientific interest.
a. IN THE APPAI.ACHAIN BKI/T.
In describing the distribution of peridotites, mention has already
been made of the occurrence of corundum in Pennsylvania, North
and South Carolina, Georgia and Alabama. In these states, the
corundum localities are found along the peridotite belt .indicated
on the general map (plate II, p. 32). Other localities are found as
16
64 CORUNDUM AND BASIC MAGNESIAS ROCKS.
indicated above, which are not intimately connected with these
rocks ; but thus far none of these, except the emery of Chester,
Massachusetts, has become of economic importance.
Corundum in Alabama. — The Appalachain crystalline belt
passes under the Cretaceous and later sedimentary formations
in the central part of the State near Montgomery. Representatives
of the peridotite belt have been found in the vicinity of Dudley-
ville, in Tallapoosa county, and corundum has been found in frag-
ments on the surface both in this and Coosa, the adjoining county
on the west. A little search would doubtless reveal the presence
of peridotite, and perhaps also,' corundum, to the very borders
of the crystalline rocks.
Corundum in Georgia. — A series of scattering deposits extends
the peridotite belt through this State in a northeast direction, pass-
ing in a general way up the valley of the Chattahoochee river to
the western extremities of North and South Carolina. Along this
line, corundum has been found in the following counties : Rabun,
Towns, Union, Lumpkin, Habersham, Hall, Cobb, Paulding, Doug-
las, Carroll, Heard, Troup, and somewhat off the line to the east,
in Walton. One occurrence is reported in Forsyth county in a
region of mica schist and garnetiiierous horneblcnde gneiss. Con-
siderable work has been done along this belt in the nature of
prospecting, and for a number of years, a productive mine was
operated at Pine mountain, in Rabun county. *
Corundum in South Carolina. — Corundum is reported from
Laurens, Anderson and Oconee counties, and I have seen speci-
mens that were said to have been found in Pickens. The western
portion of this State is in the line of peridotites as indicated
by the direction of the belt in Georgia and North Carolina, and
these rocks are known to exist along the border in the north-
western corner; but no work has been done to trace out their
distribution nor to develop the corundum deposits, if such exist.
Corundum in North Carolina. — As remarked above, this State
presents the greastest development both of peridotite and corun-
dum. The belt here attains its greatest width, and the largest
*A Preliminary Report on the Corundum deposits of Georgia, by Francis P. King, 1894
Bulletin No. 2 of the Geological Survey of Georgia.
DISTRIBUTION OF CORUNDUM.
65
outcrops of chrysolitic rocks in the Atlantic States are found in
the southwestern counties. As indicated on the map, (plate I)
corundum occurs in Clay, Macon, Jackson, Haywood, Transylvania,
Buncombe, Madison, Yancey and Mitchell counties along the belt
of basic magnesian rocks ; and it is found east of the mountains in
the counties of Cleveland, Burke, Gaston, Alexander, Iredell and
Guilford. More particular mention is made of these localities
under another head beyond.
Corundum in Virginia. — Thus far I have been able to find cor-
undum reported from only two localities in this State. The first
is a large deep blue crystal found in Louisa county by Mr. Louis
Zimmer, and reported by Mr. George F. Kunz.* The second is
that described by Dr. Genth in 1890, and noted above in describ-
ing the mode of occurrence in gneiss. The peridotite belt is con-
tinued through the State by a great number of talc and serpen-
tine rocks, but no corundum has been reported from any of these
localities.
Maryland. — Although the peridotite belt is well represented in
this State, no corundum localities are known.
Corundum in Pennsylvania. — The serpentine belt that comes
diagonally across Maryland, is continued through the counties of
Lancaster, Chester, Delaware, Montgomery and Bucks. Corun-
dum is found associated with it in many places, especially in
Chester and Delaware counties, and, a few years ago, wTas mined
to a certain extent in the former. It is found here in chloritic
zones about the serpentine, but in larger amounts in granular
albite, much like the occurrence in feldspar veins at Buck creek, in
Clay county, North Carolina.
Zones of chloritic minerals along the borders of the serpentine
masses and in the larger joints, are constantly present in these cor-
undum localities, and chromite is found in the mass of the serpen-
tine itself. Considerable prospecting has been done in Pennsyl-
vania, and corundum has been mined in one or two places but
these are now abandoned.
Corundum in New Jersey. — The crystalline belt disappears
*George F. Kunz, Mineral Recources of the United States, 1883-4, page 736.
66 CORUNDUM AND BASIC MAGNESIAX ROCKS.
under the Jura-Trias near Trenton, almost immediately on crossing
the Pennsylvania line. Portions of it outcrop again to the north-
ward in the Highlands, but in the line of the perhiotite belt, it
does not reappear till we find it on the opposite side of the State
at Hoboken, where serpentine is found, but no corundum.
Corundum is found, however, in Sussex county along the bor-
ders between the crystalline limestones and the gneiss.
Corundum in New York. — Corundum is also found with the
white limestone of this State in Orange county. Emery, an
intimate mixture of granular corundum and magnetite, is found
east of Peekskill, in Weschester county, in basic magnesian rocks.
which have been shown to be eruptive in origin.* This Emery is
also often intimately intergrown with chlorite and green spinel,
though there are no well defined chlorite zones such as are devel-
oped about the^ peridotites of North Carolina. This has been
mined to a limited extent, though the product is said to have been
too soft, and it is not worked now.
Corundum in Connecticut. — Connecticut has thus far furnished
only surface specimens of corundum, nothing of commercial impor-
tance. Early in the century, a mass of cyanite was found at Litch-
field, "associated with talc, sulphuret of iron, and corundum . . .
supposed to weigh 1500 pounds."! Dana also reports it from
Norwich. Both of these localities are in regions of crystalline
rocks.
Corundum in Massachusetts. — About thirty years ago, the
emery vein at Chester was found in a chlorite schist zone lying
between a talc rock on the east and a horneblende schist on the
west. The vein traverses the mountains on both sides of Westfield
river, in a nearly north and south direction, and has been traced
for a distance of about four miles. A typical section from west to
east would be about as follows : (a.) Horneblende schist, black,
coarse crystalline, often feldspathic and banded, gneissic; (b.) Chlo-
ritic schist, bearing lenticular masses of emery and magnetite,
sometimes becoming talcose, and often bearing radiating tourma-
*George H, Williams, American Journal of Science, 3. 1886. XXXI: pasres 26 41: 1887,
XXXIII, pa^es 135 144 and J91-199; 1888, XXXV, pages 438-448 ; 1888, XXXVI, pages 254 26^.
tEdward Hitchcock, American Journal of Science, 1, VI, 1823, page 219.
CORUNDUM IN NORTH CAROLINA. 67
line clusters. This belt is usually about twenty feet wide, (c.)
Granular quartz in a vein one to two feet wide ; sometimes entirely
disappearing, (d.) Talc schist, sometimes chloritic and of fine
texture, closely resembling serpentine; fifteen to twenty feet wide.
(e.) Mica schist to the eastward.
The position of the emery in the chloritic zone (b.) is very
variable, and it often lies along the border of this and the talcose
rocks (d). The emery is associated with diaspore and margarite,
especially about the edges of the lenticular masses. Grains of
corundum are said to be found in the talc rocks sometimes. This
locality is still worked, and is the only productive emery mine in
the United States.
A few years after the discovery of emery at Chester, corundum
was found in brown, scaly vermiculite associated with asbestos
and other amphibole minerals in Pelham, Massachusetts. Pro-
fessor B. K. Emerson informs me in a private letter that olivine
rocks are also found here, and that the occurrence is very similar
to the corundum localities of North Carolina. This locality has
thus far proved of only mineralogic interest, however.
In the numerous serpentine localities of the State, no corundum
has been found.
b. CORUNDUM IN NORTH CAROLINA.
We come now to a more detailed consideration of the corundum
localities of North Carolina. In a general way, these are all
indicated on the map (plate I), except those of Gaston and Guilford
counties ; and in the following enumeration of localities the per-
idotite belt will be considered first — beginning with thf southwest-
erly corner of the State — and afterwards, the localities east of the
mountains.
Corundum in Clay County. — One mile south of Elf postoffice,
on Shooting creek, and five miles southeast of Hayesville, perido-
tite occurs within about a mile of the Georgia line, and corundum
is found associated with it in its most southerly outcrops, on the
property of W. C. Ledford. It occurs here in "sand veins" in
scaly vermiculites ; and, a little further north, it occurs in feld-
68 CORUNDUM AND BASIC MAGNESIAN ROCKS.
spar veins and green chlorite, on the land of Samuel Housed. On
the same place, it is found in feldspar, associated with zoisite,
forming considerable masses; also in rounded nodules with rhom-
bohedral parting (as in figures 1 and 3) highly developed, and cov-
ered with a very variable coating of white compact mineral
(margarite?) which has undoubtedly been formed from the alter-
ation of the corundum. Sometimes only small grains remain in
the center of the nodules, while the coating has developed to great
thickness.
About Elf, are found outcrops of the bright green amphibolite :
and one place near the postoffice by the roadside, shows beautiful
red corundum plates and grains, also having the rhombohedral
parting. Sand corundum and the massive variety with feldspar
were obtained in the Behr mine, at Elf. Corundum has been found
on the surface and ploughed up in fields along the continuation of
this peridotite strip up Lick Log branch almost to the gap between
this and Tusquittah creek.
Except a few loose surface fragments near Shooting creek post-
office, no corundum has been found along the strip of dunite and
talc that passes across the head- waters of Shooting creek, till it
reaches the slopes of Chunky Gal mountain at Newton Penland's.
From this point it has been found all the way up the mountain
side to about half a mile east of the summit, where it narrows to
very small dimensions and finally disappears. The occurrence in
feldspar predominates toward the point of this outcrop, and this
mode is found along with the sand veins and crystal corundum on
the mountain side also. A decomposed amphibolite, bearing cor-
undum disseminated through the mass in small grains, is now being
extensively prospected near Penland's, and encouraging results
are reported.
About three miles from Shooting creek postoffice, on Thumping
creek, at Curtis Ledford's, is the corundum locality in gneiss
described above under modes of occurrence (p. 61). Corundum is
found here in rounded nodules in the gneiss and in veins of black
mica ; and is also developed in vermiculite beside one of thehypers-
thenite dikes. Some work has been done here, and portions of the
rocks exposed are quite thickly studded with corundum.
CORUNDUM IN NORTH CAROLINA. 69
At the head of Muskrat fork of Shooting creek, and about half
way up the side of Chunky Gal mountain, corundum is found in
garnet rock and brown scaly mica. This is also described above
under the occurrence of corundum in gneiss (p. 61). This was being
prospected at the time of my visit in the summer of 1894, and
the work is said to have been resumed again this year (1895).
The only remaing deposit in Clay county is that with the great
peridotite mass at Buck creek. The corundum mined here is
found in veins of coarse* feldspar and horneblende near the eastern
edge of the peridotite. In fact, only a few feet of these rocks inter-
vene between the corundum-bearing vein and the gneiss. Some
corundum is also found in the vermiculite and chlorite that are
developed through joints of the peridotite on the hillside west of
the creek ; and some is f ;und here also in feldspar associated with
zoisite and margarite. Portions of the bright green amphibolite
at this locality are quite full of corundum ; this is especially true
of that on top of the mountain west of the creek, where the ground
was covered with fragments of this rock ; but many of these have
been collected and hauled to Corundum Hill to be crushed and
separated. The locations of the corundum workings at this place
are represented on the map (plate III, page 34).
Corundum in Macon County. — I have visited and located on
the map a great number of peridotite and soapstone outcrops in
the valley of the Little Tennessee river above Franklin ; but, so
far as I was able to learn, corundum has been found at only
one of those places. A number of them show considerable
development of chlorite, and a little careful search in such places
might be well rapaid. The locality referred to is at the head of
Hickory Knoll creek, at an elevation of about 4000 feet, on the
western slope of Fish Hawk mountain. A number of small dunite
outcrops are found here, most of the blocks exposed near the
surface having a well developed radial enstatite casing. Some
corundum has been found in small encased nodules.
Six miles southeast of this, and just south of mount Scaly, cor-
undum is found in small crystals and grains with outcrops of
soapstone and a fibrous, asbestos-like mineral. Radiating casings
70 CORUNDUM AND BASIC MAGNESIAN BOCKS.
*
of talc here enclosing an ochreous earthy material doubtless repre-
sent the peridotite, which does not appear on the surface.
The next corundum region encountered lies seven miles east of
Franklin, just north of the Cullasaja river, and included between
its tributaries, Ellijay and Walnut creeks. On this, one of the
most prominent western spurs of the Cowee mountains, are found
more promising corundum localities than in any other region of
equal area within the State, or indeed, in the whole Appalachian
crystalline belt. At the southern point of this spur is Corundum
Hill, the most widely known mine, and the one that has furnished
by far the greater part of American corundum since the beginning
of the industry. A map (plate TV,) and description of this place
are given under the head of the distribution of peridotitite (p. 36),
and a sketch of its history will be found beyond.
It is entirely unnecessary to add anything further here about
the occurrence of corundum at this place. In this region, having
a total area of less than twenty square miles, there are at least fif-
teen outcrops of peridotite; and corundum in greater or less quan-
tity has been found associated with nearly all of them. Consider-
able prospecting has been and is now being done, and a great deal
of capital has been invested there within the past three years.
Corundum has been found and some prospecting done in the
gneiss on the summit of Turkey knob, on the Macon-Jackson county
line, and fine specimems of red corundum are found in the gravels
of Cowee creek. Well formed crystals are also found at Xona
postoffice, seven miles west of Franklin, in the soil of gneiss.
Corundum in Jackson County. — Loose fragments and crystals
of corundum have been found at Addie, on the ring of peridotite
that lies northeast of Webster, (see (plate Y, p. 38.) but pros-
pecting has not yet located any important deposit in place. Good
specmens of red corundum are found in gravel beds on the head-
waters of Cullowbee creek.
On Caney Fork, two miles above its mouth, corundum is found
in the chlorite schist in the manner described on page 57, on
Mrs. Chastain's place and at Marion Long's. By digging a very
shallow pit, a width of eight feet of this rock was exposed which
was thickly studded with nodules of corundum. On Johns creek,
CORUNDUM IN NORTH CAROLINA.
71
half a mile above its junction with Caney Fork, a chlorite schist
outcrop occurs with a width of about a thousand feet. Corundum
is said to be found in fragments over the surface, but no prospect-
ing has been done.
At the mouth of Chastains creek, five miles up Caney Fork,
corundum is found in the gneiss near the residence of W. W.
Biown. It is in nodules one-half to one inch in diameter, and
surrounded by a thin, compact casing. Two miles up Chastains
creek, corundum is found in the same manner in the gneiss, near
a belt of chlorite schist. At many points along Caney Fork, cor-
undum is reported to be found in the fields and elsewhere over the
surface. So far as I was able to learn, corundum has been found
in only one place on West Fork, and that in association with a
chlorite rock on Shoal Creek mountain, four miles north of Glen-
ville.
South of Sapphire, corundum is found with peridotite on Snake
ridge at several places; and on the lands of Dr. C. Grimshawe,
near Montvale postoifice, in both Jackson and Transylvania coun-
ties.
At the Sapphire mines, corundum is found in similar associa-
tions in a great number of places on both sides of Horespasture
river, and on the spars of Great Hogback mountain. Several of
these localities have been mined by the Sapphire Yalley Company,
and have yielded considerable quantities of corundum for the
market. In a number of the outcrops, enstatite rock predominates,
though more or less peridotite may be seen in nearly all of them.
The mutual relations of these two rocks at some of the localities,
as at the "Sapphire1' mine, is such as to strongly point to the
derivntion of the enstatite from the olivine.
Besides a number of places that have been prospected, the fol-
lowing localities have been mined, to a greater or less extent, and
constitute jointly the Sapphire mines. I am indebted to Mr.
Charles N. Jenks, the superintendent, for the characterization of
the product of the different workings.
The "Burnt Rock" mine is a mile and a half northeast of Great
Hogback mountain, and produces nodular, massive corundum.
72
CORUNDUM AND BASIC MAGNESIAN ROCKS.
Some of the blocks taken out weighed as much as twenty-five
pounds.
The "Brockton" mine is about a mile south of the Burnt Rock,
and its product is a dull gray crystal corundum, which is easilv
separated from the vermiculite ganffue.
The "Rattlesnake" mine is a mile and ahalf southwest of Great
Hogback mountain and about the same distance northeast of
Sapphire. Crystal and sand corundum are found here in chlo
rite and vermiculite about the borders of the enstatite rock.
The "Sapphire" mine is somewhat less than a mile northeast
of Sapphire, and near where the Brevard road crosses Big Hog-
back creek. The product of this place is crystals and masses of
white and gray corundum specked and mottled with blue.
The "Socrates" mine is half a mile south of Sapphire, on the
north end of Bear Pen mountain. The corundum here is neither
in crystals nor masses, but occurs in "shotty" nodules in the chlo-
rite veins through enstatite rock. This furnishes the most perfect
grain produced by these mines, and is well adapted to the manu-
facture of either cement or vitreous wheels.
The "Bad Creek" mine is on the west side of Bear Pen moun-
tain and about half a mile from the Socrates mine. The corun-
dum here is massive, and occurs with chlorite, margarite, garnet,
biotite, feldspar, and a number of rarer minerals, forming a hard,
tough vein. Mr. Jenks informs me that corundum constitutes
about 35 per cent, of the whole mass, but that it is very difficult
to separate it thoroughly from the gangue.
The " Whitewater" mine is about six miles southwest of Sap-
phire, on Whitewater river. The corundum occurs here in col-
ored crystals, possessing some gem characteristics, and producing
a good solid grain.
All of the lacalities enumerated lie near the Jackson-Transyl-
vania county line, and the first three are situated in the latter
county. A number of intermediate outcrops have been prospected
a little, and still others yet remain untouched.
Corundum in Transylvania County. — The Sapphire mines
"Burnt Rock," "Brockton,'' and "Rattlesnake, " described above,
are located in this county, on the spurs of Great Hogback mountain.
CORUNDUM IN NORTH CAROLINA. 73
Corundum is said also to be found with enstatite rocks in the
same vicinity, on the headwaters of the Toxaway river.
On the West fork of the French Broad river, I saw corundum
with similar rocks on the hill just west of the mouth of Owens
creek. A number of shallow pits had been dug in prospecting,
and large masses of margarite had been thrown out, bearing cor-
undum and black tourmaline Asbestiform minerals are also
found at the same locality.
A large number of similar outcrops are found to the eastward
and northeastward, and corundum is said to occur with some of
these on the North Fork of the French Broad river; but I was
unable to verify these reports, owing to the profound air of secrecy
maintained by the alleged discoverers.
Near the mouth of Owens creek, east of the corundum locality
described above, a number of large boulders of disthene (cyanite)
have been found on the surface, bearing grains and crystals of
deep sapphire-blue corundum. The rocks at this locality are
ordinary gneiss.
Corundum in Haywood County. — On Pigeon river, at Retreat
postofhce, six miles southeast of Waynesville, corundum is found
with cyanite and margarite in crystals scattered through the soil.
The rocks are garnetiferous mica schist and gneisses, and no
deposit has yet been found in place.
Three miles northeast of Canton, corundum has been found on
the surface with an outcrop of dunite, but no workable deposit has
been discovered. A mile north of this, at the "Presley mine,"
corundum occurs in pegmatite veins through dark green horn-
blende rock. The corundum occurs both in the mica and the
feldspar of the pegmatite, and is sometimes wrapped in margarite.
It often has the appearance of having altered into these minerals.
Just south of Newfound gap, red corundum is found on the
surface about a small lenticular mass of dunite. It is also reported
from a soapstone outcrop near the gap between Cabes and
Crabtree creeks.
Corundum in Buncombe County. — Just south of the Carter mine,
near the Madison county line, corundum is found about Democrat
71
CORUNDUM AND BASIC MAGNESIAN EOCKS.
with the long strip of peridotite which crosses Big Ivy river at
this place. The Carter mine is in Madison, and very little pros-
pecting has been done in Buncombe.
At Swannanoa gap, on the eastern border of the county, cor-
undum is occasionally found in masses of cyanite.
Corundum in Madison County. — The Carter mine is very near
the Bumcombe county line, in the eastern end of the county, and
is situated on Holcombe branch, a tributary of Little Ivy river.
It is at the north end of the strip of dunite which is continous
from Morgan Hill, in Buncombe county. The corundum here
occurs in a vein of chlorite and vermiculite which is developed
at right angles to the lamination of the peridotite. It is in
masses of white, pink, and blue colors, and is intergrown
with greenish black, massive spinel and feldspar.
Recently, Mr. John A. Carter, of Democrat, has found a crys-
tal of mottled bine and white corundum weighing -16 pounds. It
is hexagonal in form, though rough and irregularly broken, and has
the rhombohedral parting well developed. It was found loose
above the Carter mine in a small stream very near its head, but
search failed to discover its source.
Fig. 7. Hexagonal crystal of corundum showing rhombohedral twinning. A, oblique
view; B, end view; one-fourth natural size; weight 17 pounds. From an amphibolite out-
crop half a mile north of the mouth of Ivy river, Madison county. (Specimen in posses-
sion of Mr. G. C. Haynie, Marshall, N. C Figure drawn from photographs.)
The first corundum found in North Carolina was picked up
from the surface three miles below Marshall, just above the mouth
of Little Pine creek. A belt of soapstone and peridotite crosses
CORUNDUM IN NORTH CAROLINA.
75
the river near this point, but the locality has never furnished a
second specimen, so far as I was able to learn.
Three miles above Marshall and half a mile north of the mouth
of Big Ivy river, corundum is found in large gray crystals on
the surface of a large hornblende outcrop. One crystal from
this place (figure 7), which weighs 17 pounds, and exhibits fine
rhombohedrol twinning, is in possession of Mr. G. C. Haynie, of
Marshall, the owner of the property.
Corundum in Yancey County. — The principal corundum local-
ity of this county is that known as the "Egypt (or Hayes) mine,"
ten miles west of Burnsville, on the western slopes of Sampson
mountain. Corundum occurs in green chlorite along the bor-
ders of dunite and enstatite rock, the latter predominating. It
is generally in distinct crystals, though granular massess are
also found. The prevailing colors are white and banded or mot-
tled blue and white. The corundum imbedded in dunite (figure
5), and the crystal shown in figure 3 are from this locality.
Eight miles southeast of Burnsville, on Celos Ridge, near
South Toe river, corundum is found in crystals of two or three
inches in diameter in the decomposed gneiss adjoining an out-
crop of enstatite rock.
Corundum in Mitchell County. — Three-fourths of a mile west
of Bakersville, corundum crystals are found in the gneiss at Wil-
liam Bowman's. I also saw fragments of corundum on the sur-
face and in the dump a mile and a half up White Oak creek from
Bakersville, where work had been done for asbestos. The rock
is a massive enstatite with fine radiating borders similar to those
found about dunite in many places.
Since my visit to this region, Mr. D. A. Bowman, a local min-
eralogist, of Bakersville, writes me that "one mile due east from
Bakersville, a massive blue corrundum occurs, with now and then
a hair-brown piece." He further states that in the sumer of 1888
he obtained about 600 lbs. at this place, one piece of which
weighed 23£ pounds. "Some small blue crystals found at this
place would cut very nice gems were it not for cleavages."
~No corundum has yet been found in North Carolina north of
Bakersville.
76
CORUNDUM AND BASIC MAGNESIAN ROCKS.
Corundum in Iredell and Alexander Counties. — The country
rock in these counties is ordinary gneiss, and surface specimens
of corundum are found scattered over a large number of local-
ities, especially in Iredell. Grayish masses are found several
inches in diameter, and the smaller ones frequently have crystal
form. All are more or less altered, and most of the specimens
have a sheath of compact damourite or margarite, (figure 8) which
is sometimes developed to such an extent that only a trace of
the original corundum remains in the interior.
Fig. 8. A tapering crystal of black corundum enclosed in a sheath of compact mar-
garite. One-half natural size. From Belts bridge, Iredell county. (Drawn from a pho-
tograph.)
In the alluvial deposits first worked by the Acme company at
Statesville, blue and pink corundum was found in clays and
sands, either in small loose pieces or in masses with cyanite. On
passing through the clays and gravels, a massive hornblende
rock was encountered, and a little search discovered a vein of
feldspar bearing corundum and separated by vermiculite from
the hornblende rock through which it passed. In its widest
place, this feldspar-corundum vein had a thickness of two and a
half feet, and was very rich in corundum.
The only other locality where corundum has been found m
place in this region is eight miles northwest of Statesville, and
just north of the Charlotte and Taylorsville railroad, on the Hun-
ter place. Here no such alluvial deposits were encountered, and
the amphibolite is of much finer texture than that at Statesville.
But otherwise, the occurence is very much the same. The cor-
undum is almost coal-black and is associated with feldspar and
vermiculite in the joint system of the rocks, much in the same
manner as that found in some of the dunite localities of the moun-
tain region. The mode of occurrence is described and illustrated
CORUNDUM IN NORTH CAROLINA.
77
(figure 6) on page 93. Near this place, large masses of corun-
dum with margarite are found on the surface. The soil and
decomposed rock are so deep over this region that very little can
be determined about the form or extent of these amphibolites.
Only occasionally does a stream or a wash in the hill side offer
an exposure of rock that may be readily recognized.
Corundum in Burke and Cleveland Counties. — lam indebted
to Mr. H. B. C. Nitze for the following notes in regard to the
•occurrence of corundum along the borders of Burke and Cleve-
land counties, near the corner of Catawba. The rocks of the
region are highly garnetiferous, gneissic, mica schist. Grayish
blue, tapering corundum crystals are found on the surface along
the ridge leading northwest of Carpenters knob. On the waters of
the South Fork of the Catawba, in Burke county, corundum of a
similar nature is found in "pockets" containing from one to two
hundred pounds. Monazite is found in the placers of the streams.
Dr. Genth mentions "crystals of corundum surrounded by fibro-
lite" from this locality.*
Corundum in Gaston County. — Corundum was discovered in
this county at Crowders, Chubbs, and Kings mountains by Dr.
C. L. Hunter, about forty years ago. It was found in masses and
six-sided crystals "in place — associated with mica and quartz
aggregate." Margarite was found with it ; and, in places, by the
gradual introduction of iron oxids, a transition to granular emery
was observed. ~No large quantities have been found here, and
thus far, the discovery has proved of only mineralogic interest.
Corundum in Guilford County. — In the titaniferous iron ore
belt that traverses the northwest corner of Guilford county, Dr.
Genth found true emery at the McChristian (or McCuiston) place,
seven miles north of Friendship. One variety was reddish, gran-
ular, and had "much the appearance of agranular reddish brown
garnet, for which it has been mistaken, until the analysis proved
it to be not a silicate, mixed with granular magnetite, but corun-
dum." Another, found in the same locality was grayish in color;
^Bulletin 74, U. S. Geological Survey, 1891. The Minerals of North Carolina, page 30.
78 CORUNDUM AXD BASIC MAGXESIAX ROCKS.
and "the minute crystals of eorudum have a yellowish or brownish
white color, and show in many places cleavage fractures,
which give it the appearance of a feldspathic mineral."^
The following analyses of these varities are given in the same
place.
Analyses of J^mery from the McChristian place, 7 miles north of Friend-
ship, Quilford county.
REDDISH BROWN. &RAY.
Silica 1.39 0*98
Titanic acid 0.78 2.42
Magnetic iron oxid r.. 42.77 46.29
Oxid of Manganese and Cobalt 1.00 1.27
Chromium oxid 0.80 trace
Alumina 52.24 44.86
Magnesia 0.68 3.27
Lime 0.84 0.91
100.00 100.00
Corundum in other localities. — Tn the report of the North
Carolina Geological Survey for 1S75, large hexagonal crystals of
corundum are reported from Forsyth county (page 299), and a
reddish variety from Polk (Appendix page 65). Small particles
are also said to occur in cyanite in Wilkes county : and Dr.
Genth says that "rarely small remnants of corundum are found
in the pyrophyllite slates of Chatham county." He also men-
tions the locality of Y alley river in Cherokee county for corun-
dum, and says that emery is found near Salem, Forsyth county. +
I have not yet had an opportunity to verify these reports, but
hope to do so before publishing a final report on this subject.
(6.) METHODS OF PROSPECTIXG FOR CORUXDUM.
The early discoveries of corundum in North Carolina were not
the result of any systematic search ; in fact, corundum, as it is
now known in this State and Georgia, was not then a commer-
*Report of the Geological Survey of North Carolina, I., 1815, pages 245, 246.
tBulletin 74, U. S. Geological Survey, 1891, pages 29-31, 96.
METHODS OF PROSPECTING FOR CORUNDUM. 79
cial mineral, and nothing was known of its occurrence with
peridotite. Accidental finding of surface fragments led to the
discovery of extensive deposits ; and the subsequent working of
these and other localities has given to mineralogy and mining
a great fund of information on this subject that is to a large
extent entirely new. As usual in the case of things new, many
mistakes were made in early prospecting and attempts at
mining. Mistakes are made yet, and they will doubtless con-
tinue for some time to come, but many of the earlier errors need
not be repeated if due regard is had to the store of information
that has been accummulated by more than twenty years of expe-
rience.
Those who would search for corundum had best see, first of all,
an actual corundum mine or a place where prospecting has been
done and corundum found; and note carefully the conditions. In
the southwestern portion of the State this may easily be done with-
out great inconvenience. If the preceding pages have been read,
or even a small portion of them, it will already be understood
that conditions are rarely duplicated exactly, even in localities
very near together. Certain types of rocks and minerals, how-
ever, may be observed in the greater number of them ; and these
may be profitably used as guides in searching for new localities.
Of course the prospector must be able to recognize corundum
itself in all of its common forms.
Loose fragments of corundum in the soil or stream beds are,
of course, the surest "signs" of corundum deposits, though not
always the most easily traced to their origin. The extreme
resistance of the mineral to the ordinary process is of abrasion and
decomposition render it almost indestructible when exposed on the
surface. Hence, it may be transported tor great distances down
the mountain slopes and streams without showing any apprecia-
ble alteration and but little wear. When associated with frag-
ments of peridotite, chlorite, or talc, the corundum is a much
more valuable guide. In such cases, it has probably been trans-
ported only a short distance, and the search for the source
becomes far less difficult. Where no corundum is found with
80 CORUNDUM AND BASIC MAGNESIAS' ROCKS.
the rock fragments or minerals indicated, and none is found by
panning the soil or sand, as in the ordinary search for gold, there
is little encouragement to seek further.
The "indications" are followed up the grade by which they
would most naturally have reached their present position. If in
a stream bed, the search is made up the stream or its tributaries
till fragments are no longer found, and then up the adjoining
hillsides till the parent mass of peridotite is reached. The bor-
ders of this rock are first examined. If the border is not readily
found by inspection, ditches are cut through the soil and decom-
posed surface materials at right angles to the strike of the
country rock. The chlorite and vermiculite along the contact
between the gneiss and peridotite should then be examined for
corundum. A ditch, passing completely through the soil,
should follow this contact zone; and, at intervals, shallow pits
or cuts should be sunk to disclose the nature of the deposit.
Where no encouraging development is found about the borders,
it may be worth while to cut ditches across the peridotite mass
for the examination of the joint zones; but these are usually less
developed than those about the borders.
Margarite is found abundantly with corundum in some places,
but in the majority of the North Carolina localities, this is not
true, and its discovery usually follows, rather than precedes,
that of the corundum. The emery mine at Chester, Massachu-
setts, however, was discovered by the finding of this mineral,
and, when found, it is to be regarded as a good "indication."
Obviously, the points given above apply chiefly to corundum
associated with peridotite. It is found, however, in a number of
other associations in the State, and several of those in amphibo-
lite and gneiss give promise of becoming of commercial import-
ance. For these occurrences, there seems to be no important
index, except to find the corundum itself. When it is developed
in considerable quantity, there should be no difficulty in finding
it in the soil and in the gravels of the adjacent streams.
In some cases, where chlorite and vermiculite are found
abundantly on the surface, it may be advisable to trace them to
their origin, even though corundum may not be found floating
MINING AND CLEANING METHODS. 81
in the soil with them. Corundum itself, however, is the only
sure indication of new deposits, and other guides, though often of
valuable assistance, should be regarded as pointing only to proba-
bilities.
An ordinary wash-pan, or even a shovel, will serve very well
in examining the gravels or soil; and any one may readily deter-
mine for himself whether corundum occurs in a given locality.
By a little practice, all the heavy minerals in the soil or gravel
may be shaken to the bottom of the pan and the lighter mate-
rials washed off over the edge. The heavy minerals will be found
usually to contain grains of magnetite, garnets, dark hornblende,
and corundum, if any is present.
Finally, however good the indications, even from the presence
of corundum itself, no extravagant anticipation or large invest-
ments are justifiable till the deposit has been thoroughly
explored by intelligent prospecting. Had this truth been borne
in mind, trite as it may seem, much disappointment and financial
loss would have been avoided and the mining reputation of the
State saved many serious blows.
(7.) MINING AND CLEANING METHODS.
Twenty-five years ago, the corundum fields under considera-
tion were entirely new to the mining world. Corundum itself,
as a commercial article was scarcely known except in the forms
of emery and the gems; as an associate of peridotite, it was not
even known to mineralogy. There were no precedents in min-
ing, and every step was evolved by the slow and expensive pro-
cess of experiment. Undue excitement had been created by the
finding of a few gems, and the idea that corundum might be
profitably mined as an ordinary abrasive had scarcely been con-
cieved.
Under these conditions, the first undertaking (at Corundum
Hill) was naturally a failure. A hydraulic method with short
sluice systems was adopted for working the corundum-bearing
soil and gravels, and some of the chlorite zones were opened.
Only the larger crystals and promising gem materials were saved.
82 CORUNDUM AND BASIC MAGNESIAN ROCKS.
With the exception of the gems, the product was sold for cabinet
specimens and for the manufacture of dental appliances ; but the
work was soon found unprofitable. The concentrated gem-bear-
ing gravels were exhausted, and the mine abandoned.
Two great mistakes were made in this early work ; first, too
much importance was attached to gem mining ; and, second, the
smaller fragments, or "sand-corundum," which afterward became
the most important product, were allowed to waste. Prospect-
ing, and some small attempts to mine in other localities during
the next few years, soon demonstrated the scarcity of true gems.
When Dr. H. S. Lucas reopened the work at Corundum Hill, it
was purely for the purpose of mining corundum as an abrasive.
and methods were adopted for saving the whole product of the
mine. On this basis, the work has been successfully continued
to the present time, not even closing down entirely during the
panic of 1893 and 1894.
Mining Methods. — Naturally, the methods of work adopted in
the few places that have really been mined, as distinguished from
prospecting, have varied greatly, according to location, character
of material, and other variable conditions. The area under con-
sideration is located entirely in the mountainous and hilly districts
of the western part of the State, and the outcrops are usually on
high ground, with abundant natural drainage. These conditions
and the nature of the border zones of chlorite and vermiculite.
which are the principal deposits worked, have led to the adoption,
in the majority of cases, of open cuts and drifts.
So long as the work is confined to the comparatively superficial
portions of the deposit, the open cut is the most advantageous.
But, with increase in depth, the jointed peridotite, with its great
development of slippery magnesian minerals along the cracks, is
exceedingly liable to fall in. Such cuts at Corundum Hill, at a
depth of twenty to thirty feet, have loosened great masses, and
have sometimes produced cracks in the surface at a considerable
distance from the working. These are a continual menace to the
miners; and, in a few cases, they have slipped into the cuts,
though without more serious result than to stop the work.
MINING AND CLEANING METHODS. 83
The same trouble, though to a less degree, is sometimes exper-
ienced in drifts, and it is very difficult to timber the workings in
such a manner as to be perfectly safe. Much of this trouble,
however, is really due to unsystematic work and employment of
unskilled men. After the work in open cuts had been rendered
impracticable at Corundum Hill, the mining was continued by
drifts. In one place, several of these have been driven, one
above another, in the same vein.
In a few localities, small shafts have been sunk, but generally,
this is done only where the configuration of the surface is not
favorable to cuts and drifts. The expense of hoisting and pump-
ing incurred in shafts is probably the chief objection to them.
The material handled, in the great majority of cases, is loose,
scaly chlorite and ' vermiculite with corundum disseminated
through it, and is easily removed with a pick and shovel. In
solid feldspar veins, however, as in some of the Sapphire mines,
and at Laurel Creek (Ga.) and Buck Creek, blasting has to be
resorted to, and afterward the material crushed for cleaning.
One of the drifts at Corundum Hill is now being cut through
the gneiss wall adjoining the peridotite. It is very hard and
thickly impregnated with corundum, and must, of course, be
removed by blasting. In removing the material from the mines,
hand cars and wheelbarrows are employed. It is then, according
to its nature, dumped into wagons or sluice-troughs to be carried
to the mill for cleaning.
Methods of Cleaning. — The prime object of all methods of
cleaning corundum is, of course, the removal of all impurities as
completely as possible ; for any other mineral that is ever found
in association with corundum, though it may be very hard itself,
is always softer, and if left with it in considerable quantity, will
appreciably reduce its abrasive power. But the mere removal
of impurities is not the only point to be considered in devising
methods of cleaning. This must be done with the least possible
injury to the cutting power of the corundum grains. The sharp
edges attained by crushing must not be ground off, and no large
percentage of it should be lost by reducing it to " flour."
84 CORUNDUM AND BASIC MAGNESIAN ROCKS.
Owing to the high sjDecific gravity of corundum, it can be
effectually separated from most of its associated minerals by
washing methods in many ways similar to those adopted in
placer mining for gold. Where the corundum occurs loose in
chlorite and vermiculite scales, little other treatment is nec-
cessary ; but, when it is enclosed in a tough gange of feldspar,
margarite, and other minerals, or is a constituent of a solid rock,
as in the gneiss and some of the amphibolite occurrences, the
minerals must be thoroughly broken apart before separation.
For the accomplishment of this purpose, the abrasive power of
the corundum itself is used, by scouring the crushed material
together, so that the particles cut the softer minerals from each
other. All cleaning methods, then, involve the three processes,
crushing, scouring, and washing. The means by which these
processes are applied may be best understood by descriptions of
concrete cases.
Methods of cleaning Corundum at Sajyjjhire. — I am indebted to
Mr. Charles ~N. Jenks for the following outline of methods
adopted by him at the Sapphire mines.
With crystal corundum, which is found in loose, scaly vermi-
culite, only the simplest treatment is necessary. It is placed in
a box through which flows a strong current of water, and stirred
vigorously with hoes. The scaly minerals float off with the cur-
rent, leaving the corundum about 95 per cent, pure ; and this
requires only crushing and sifting into sizes to prepare it for the
market.
But with every other variety of corundum, the separation of
impurities is more difficult and the methods of treatment corres-
pondingly more complicated. The material is first broken into
coarse grains by passing through crushers and rolls. In this
process, much of the adhering impurities is broken loose ; and
this may be partly removed by the gravity process described
above ; that is, by stirring in a strong current of water. It is
then passed through a machine, in which a coarse worm, like a
screw-conveyer, is carried on a revolving shaft. In this the
adhering minerals are cut away by the grinding of the corundum
grains upon each other; after this it is again subjected to
MINING AND CLEANING METHODS. 85
the gravity treatment in a strong current of warter. The last
process, and one by which the corundum is brought to a high
degree of purity, is in a machine called the "muller", or "chaser".
In this machine, two heavy wooden rollers move around the cir-
cumference of a shallow tub. The partially cleaned corundum
is thrown into this tub, and is stirred constantly by iron
teeth that move in front of the rollers. Being thus alternately
stirred up by the teeth and pressed down by the rollers, a scour-
ing motion is continually kept up between the grains, and the
impurities are gradually cut away. In this action, the impuri-
ties are reduced to the form of a fine powder, and are carried
away by a small current of water which continually flows through
the tub. This process is continued from three to five hours, accor-
ding to the difficulty of cleaning and the degree of purity required.
Methods of cleaning Corundum at Corundum Hill. — Two classes
of material are produced by this mine; namely, the sand corun-
dum (and crystals) contained in the vermiculite and chlorite devel-
oped along the borders and in the joints of the peridotite ; and
the contact gneiss impregnated with corundum. Each of these
requires its special mode of treatment.
Until recently, the sand corundum veins were the only depos-
its worked at this mine. All of the material of this class is sent
from the mine to the mill, a distance of a mile and a half, in a
small trough carrying a swift current of water. In this course,
there are seA7eral vertical drops of five to ten feet to facilitate in
breaking loose the scaly minerals adhering to and enveloping the
corundum. At the mill, all material that will not pass through
a screen of II mashes to the inch is crushed between rolls and
passed, with the originally fine material, to the gravity boxes, or
sluices, where it is vigorously stired in a strong current of water.
It is then treated in mullers, as in the process described above.
The gneissic material comes from the minein hard, tough blocks,
sometimes quite large, and is hauled to the mill on wagons. A
very primitive method is adopted for breaking the large blocks into
sizes suitable for the crushers. A fire is built over them till they
are heated through, and then they are suddenly cooled by throw-
ing on water. Fortunately, only a small part of the product
A
86 CORUNDUM AND BASIC MAGNESIAN ROCKS.
requires this treatment. It is then passed through crushers and
coarse and fine rolls till it will all pass through meshes II to an
inch. It is then subjected to a scouring action in the auger-like
machine described above, and passed on to the gravity boxes.
The final cleaning, as in the other case, is given by the mullein.
The method of drying in use at Corundum Hill is also worthy
of notice. When the material is removed from the mullers, it is
allowed to lie over night in a heap on an inclined floor. This
material, still wet, is carried up in an elevator and dropped verti-
cally through a distance of about twenty feet down the stack of
a furnace. At the bottom of this, it strikes an inclined plane
and slides down this for a few feet through the flames of a wood
fire. By this time it is thoroughly dry, and is passed into a cham-
ber beneath, whence it is removed with shovels and subjected to
a final sifting. All material not fine enough to pass through a
screen with 14 meshes to an inch is again passed through the
rolls, and the entire cleaning process is repeated.
The corundum thus cleaned is shipped to the company's mills
at Chester, Massachusetts, where it is further crushed and sorted
into sizes for the market. The coarser numbers are also passed
through magnetic separators for the removal of the magiuetite.
7. HISTORICAL SKETCH OF CORUNDUM MINING IN AMERICA.
The following chronological outline of the principal discov-
eries and the developement of corundum mining in the eastern
United States has been compiled from the sources enumerated in
the bibliography at the end. In the main, these sources are con-
sidered reliable, and it is believed that the outline here presented
indicates with tolerable accuracy, not only the origin of the cor-
undum mining industry, but also the growth of our knowledge
of corundum in many of its most important mineralogic and geo-
logic relations.
Besides the enumerations of discoveries, I have o-iven short
DISCOVERIES AND EARLY DEVELOPMENTS. 87
sketches of all the corundum mines, properly so called, in North
Carolina.
(1.) DISCOVERIES AND EARLY DEVELOPMENTS.
So for as I have found in the literature on the subject, corun-
dum was not known in America before 1819. In that year, Mr.
John Dickson, a teacher, of Columbia, South Carolina, sent Prof.
Silliman a lot of minerals which he had collected on a tour through
the Carolinas. Among these was a regular, six-sided crystal of
blue corundum three-fourths of an inch long and one inch in diam-
eter, with parting and striae developed similar to the East Indian
corundum. It was sent without label, and in reply to an inquiry
as to its locality, Mr. Dickson writes: "I think it was Laurens
district; at all events, it was picked up by my own hands, if not
in situ, in a place which it could have reached only by one
of the usual and natural accidents which displace minerals of all
kinds I am sure it is American and Carolinian." l
In 1822, both Edward Hitchcock and Parker Cleaveland des-
cribed the mass of cyanite found at Litchfield, "associated with
talc sulfuret of iron, and corundum supposed to weigh
1500 pounds." The corundum was massive and in six-sided
prisms, of a dark grayish blue color, and imbedded in the cyanite.
Both of these authors attribute their information to Mr. John P.
Brace. 2
In April, 1827, at a meeting of the Lyceum of Natural History,
New York, "Major Delafield exhibited crystals of Sapphire
from Newton, Sussex county, New Jersey." 3 In 1832, Dr. Fow-
ler described this locality, pointing out the geologic and miner-
alogic relations of the corundum. It is found along the border
of crystalline limestone. 4
According to Mr. W. W. Jefferis (as quoted by Mr. Joseph
Willcox) John and Joel Bailey claim to have discovered corun-
dum in the serpentine region of Chester county, Pennsylvania,
about 1822 to 1825. Dr. Thomas Seal collected specimens at
1Am, Jour. Sci., 1, III., 1821, 4,229, 230.
2Am. Jour. Sci., 1, VI., 1823, 219; Cleveland's "Mineralogy and Geology,'1 Boston, 1822.
3 Am. Jour, Sci., 1, XIII., 1828, 380.
4Am. Jour. Sci., 1, XXL, 1832, 319, 320.
88 CORUNDUM AND BASIC MAGNESIAN ROCKS.
Unionville about 1832, and Mr. Jefferis himself saw large lumps
in the fields there in 1837 or 1838. l A ton of surface fragments and
boulders was collected about 1839 and shipped to Liverpool. But
the search for the source of this material was unsuccessful till 1873,
when a large lenticular mass was found in place. This consisted
chiefly of corundum and margarite and carried some fine speci-
mens of diaspore.2
In a report on the Mineralogy of New York, in 1842, Lewis C.
Beck mentions the occurrence of corundum in the white lime-
stone near Amity, in Orange county.
The first discovery in North Carolina was a large detached
block of dark blue, laminated corundum, found three miles below
Marshall, in Madison county, in the spring of 1847. Gen. T. C.
Clingman, after considerable search, found another piece in the
same vicinity in 1848 — about a year before the first discovery
of emery in place in Asia Minor by Dr. J. L. Smith.3
In 1852, Mr. W. P. Blake described corundum from the new
locality at Yernon, Sussex county, New Jersey.4 In the spring
of the same year, Dr. C. L. Hunter discovered corundum and
emery in place in Gaston county, North Carolina.5
In 1864, the occurence of emery at Chester, Massachusetts,
was predicted by Dr. C. T. Jackson from his discovery of mar-
garite there — a mineral which Dr. J. L. Smith had just found
characteristic of the emery deposits of Asia Minor. On Septem-
ber 6th of the same year, Dr. H. S. Lucas discovered the emery
in what had before been considered only deposits of magnetic
iron ore.6 Two years later, distinct crystals of corundum were
found in the same deposits.7 This discovery of emery soon led
to the establishment of active mining, the first of its kind in
America. This mine is still worked, though it has not been
operated continuously from the beginning.
> /fin 1870, Mr. Hiram Crisp found the first corundum that
ie/jfy£jl?W$$- ^jjfentionto the present mining regions of North Caro-
2d G-eol. Sur. Perm., C4, 1883, 348-351.
1 Owl. Sur. Penn., 13, 1875, 31-33.
ull. 74, U.S. Geol. Sur., 1891, 293-1.
♦Am. JoiH-. 8cl., 2, -XIII., 1852, 116.
5 Am. Jour. Sci., 2, XV.,""1§§J 3*6.
°The exact date was furnished me by Dr. Lucas in a private letter.
'Am. Jour. Sci., 2, XXXIX., 1865, 87-90; XLIL, 1866, 421.
NORTH CAROLINA CORUNDUM MINES. 89
lina. This was found at what is now the Corundum Hill Mine —
Mr. Crisp living there at the* time. A specimen was sent to
Professor Kerr, then State Geologist, for indentification, and
considerable interest was aroused on the discovery that it was
true corundum. In the same year, Mr. J. H. Adams found
corundum in very similar relations at Pelham, Massachusetts.*
In 1870-71, considerable activity was displayed in the search
for corundum in the dunite regions of the southwestern counties
of North Carolina ; and new localities were soon brought to
light in Macon, Jackson, Buncombe, and Yancey counties. In
1871, Dr. Genth also discovered the emery of Guilford county. f
About this time, Mr. Crisp and Dr. C. D. Smith began active
work on the Corundum Hill property, and removed about a
thousand pounds, part of which was sold to collectors for cabi-
net specimens. Some of the masses weighed as much as forty
pounds.
In the fall of 1871, the property was bought by Col. C. W.
Jenks, of St. Louis, Missouri, and Mr. E. B. Ward, of Detroit,
Michigan ; and mining was soon begun under the superinten-
dence of Col. Jenks.
In reply to my inquiry about the discovery of corundum in
Iredell county, Mr. J. A. D. Stephenson, of Statesville, writes
me as follows : "The first corundum found in Iredell county
was found by myself near where the Collins (Acme) mine is now
located, either late in 1871 or eariy in 1875. It was a mass
weighing probably two pounds. I also found a lot of pink frag-
ments near by." It was soon discovered in loose masses and
crystals in many parts of the county, and small amounts have
been found in Alexander, the adjoining county to the west.
(2) NORTH CAROLINA CORUNDUM MINES.
Mining proper, as distinguished from prospecting, has thus far
been restricted to a few localities in the counties of Clay, Macon,
Jackson, Madison, and Iredell. Extensive prospecting, however,
has been done at a number of places which have come to be known
*Am. Jour. Science, 2, XLIX,, 1870, 271, 272.
tRept. Geol. Sur. of N. C, L, 1875, 246.
90 CORUNDUM AND BASIC MAGNESIAN ROCKS.
locally as " mines ; " and more or less work has been done at
nearly all the localities where corundum is known to occur in
the State. Most of this has been done in the most primitive and
unsystematic manner. Little pits -are dug here and there, no
deeper than a man may conveniently throw the dirt from
with a shovel ; and trenches are dug, apparently at random, in
every direction over the surface about the peridotite outcrops.
At few of the corundum localities enumerated, has the work been
sufficient or of such a nature as would reveal the extent and
value of the deposit.
Much has been learned, however, by the experience of a quar-
ter century ; and the prospecting of recent date has been more
intelligently directed and the results correspondingly more satis-
factory. To find that a place has been prospected and aban-
doned, however, is still not to be regarded as conclusive evidence
that it is worthless ; and I have no doubt that the work now
under way, and that of the future will, in many cases, prove
the correctness of this statement.
Short historical sketches of the following mines are given
below :
a. The Behr mine, Clay county.
b. The Buck creek (Cullakanee) mine, Clay county.
c. The Corundum Hill (Cullasaja) mine, Macon county.
d. The Sapphire (Hogback) mines, Jackson county,
e. The Carter mine, Madison county.
f. The Acme mine, Statesville, Iredell county.
In the preparation of these sketches, I have had to rely partly
on such information as could be gathered piecemeal here and
there through the country ; but chiefly, and especially in regard
to the more prominent mines, I am indebted to the kindness of
superintendents and mine-owners for most of the facts presented
here. I would mention especially Dr. H. S. Lucas, who first
placed corundum mining on a successful basis, and who has been
identified with the industry for twenty years ; and Mr. Charles
~N. Jenks, superintendent of the Sapphire mines, who was asso-
ciated with his father, Col. C. "W. Jenks, in the first work of the
kind undertaken on a commercial scale. Valuable information
NORTH CAROLINA CORUNDUM MINES. 91
has also been furnished by Mr. A. M. Stoner, of Franklin ; and,
in regard to recent developments and prospecting, I am much
indebted to Mr. L. S. Ropes, of Franklin, and Dr. C. Grimshawe,
of Montvale. Mr. J. A. D. Stephenson, of Statesville, Mr. John
A. Carter, of Democrat, and Mr. IT. S. Hayes, of Bald Creek,
have furnished important data in regard to the operations in
their respective localities.
a. THE BEHR MINE, CEAY COUNTY.
This mine is located five miles east of Haysville, at Elf post-
office, on Shooting creek. It was opened in 1880 by Dr. H. S.
Lucas. It was afterward bought by Herman Behr & Company,
of New York, and was operated till 1890. A steam cleaning
plant was erected at the mine, and considerable work was done.
Much of this was doubtless of the nature of prospecting, but I
am informed that several car loads of cleaned corundum were
shipped. The location of the mine in a low place by a branch
necessitated the constant use of pumps for drainage. The near-
est railroad is about twenty-five miles distant.
b. THE BUCK CREEK (CUUUAK AJSTEE) MINE, CI, AY COUNTY. „
In the report of the North Carolina Geological Survey for
1875, Dr. C. D. Smith states that he was the first to find corun-
dum at Buck creek. Large loose blocks with feldspar and black
horneblende were found on the surface. The first prospecting
was done by Maj. Bryson about 1875 ; and two years later Mr.
Frank Meminger worked for about six months and removed
about thirty tons of corundum.
For a period of ten years no further operations were under-
taken ; then work was resumed by Mr. Ernst and continued for
nine months, chiefly in the nature of prospecting. During
another period of four years, the mine was idle ; then operations
on a liberal scale were begun by Mr. Gregory Hart, and con-
tinued for a year and a half, during which time a shaft was sunk
on the feldspar vein and several open cuts made on the chlorite
zones about the eastern border of the peridotite. Considerable
quantities of corundum were taken out during this time, but
92 CORUNDUM AND BASIC MAGNESIAS BOCKS.
nothing was shipped. Most of the product, however, was in
large massive blocks with feldspar and black horneblende, and
there was no economic method of crushing and cleaning it.
In 1893, the mine was purchased by the Hampden Emery and
Corundum Company (as it is now styled), and the material
already mined was hauled to Corundum Hill and cleaned with
the product of that mine. Since that time a little prospecting
has been done in the chlorite zones, but no farther mining; has
been undertaken.
The nearest practicable shipping point is forty miles away, but
by the construction of a few miles of wagon road, another station
could be reached within twenty miles. (See also page 69.)
G. THE CORUNDUM HILL (CULLASAJA) MINE, MACON COUNTY.
This mine is seven miles southeast of Franklin, on Cullasaja, or
Sugar Fork of the Little Tennessee river. The postoffice is Cul-
lasaja. It is well known, not only for being the first worked, but
also as the most successful corundum mine of the whole belt. Since
1878, it has afforded a constant annual product of 200 to 300 tons
of cleaned corundum. During 1893-4, the output was not so
large, but the mine was operated continuously during a period
when nearly every industry of the country was paralyzed.
The beginning of operations here in 1871, by Col. C. AY. Jenks,
has already been noted in the sketch of " Discoveries and early
developments" given above. This first mining was chiefly for
gems ; and the work was done by a hydraulic process with sluice
boxes, very much in the same manner as the process is applied to
gold mining. The surface soil and loose vein material were
washed through a series of sluices, or rather boxes, inclined about
thirty degrees. The material was constantly stirred so as to allow
the lighter minerals to float off, while the corundum and other
heavy minerals remained in the boxes. The concentrated corun-
dum thus obtained was then removed and carefully searched for
gems. Transparent and translucent fragments of ruby-red, sap-
phire-blue, yellow, green, colorless, and other shades were found.
Some of these cut good gems ; but, unfortunately, they were
NORTH CAROLINA CORUNDUM MINES.
93
always small and the quantity too limited to make the business
profitable.
The value of the so-called sand corundum was not then realized ;
and the only material put on the market, besides gems and cabinet
specimens, consisted of the larger crystals and lumps. About one
hundred tons of this corundum were mined, and sold for dental
and other purposes in this country and Europe. This material,
however, possessed a degree of purity scarcely attained in the later
product of any of the mines. The average force employed in this
work was about twelve men.
In 1878, Dr. H. S. Lucas, of Chester, Massachusetts, bought the
mine at Corundum Hill for the Hampden Emery Company, and
began operations in October of the same year. Profiting by the
experience of his predecessors, Dr. Lucas confined his operations
to the mining of corundum for abrasive purposes only; and all
corundum found — whether sand, crystals, or lumps — was saved
and worked into sizes together. The abundant water-power of
the Cullasaja was early utilized for the operation of washing and
other cleaning machinery ; and thus the business was placed on a
basis which has continued successful to the present time.
a
T-O:
■4"
mm
[Fig. 6.— Diagramatic section across the corundum-bearing zone between gneiss and
peridotite, Corundum Hill, Macon county, a. Gneiss, sometimes bearing corundum near
the border; b, Schistose talc, chlorite, and vermiculite; c, Chlorite and vermiculite in
interlocking crystalline plates with disseminated corundum; d. Similar to l> but more
talcose; e. Border of bladed and fibrous enstatite; /, Dunite. [For a description of the
formations illustrated by this figure see page 55.]
A line of sluice troughs a mile and a half in length connects
the mine with the mill, and the loose chloritic vein material is
dumped into this as fast as mined. The rolling, falling, and
94 CORUNDUM AND BASIC MAGNESIAN "ROCKS.
scouring action to which it is subjected over this course does
much toward separating the corundum from the accompanying
impurities, and it arrives at the mill in a condition which renders
cleaning comparatively easy. (See fig. 6 [p. 93] and pp. 37 and 55.)
For two or three years, the " Hosea Moses mine " on Eliijay
creek was worked by the same company, and, after a partial wash-
ing at the mine, the product hauled to Corundum Hill for defin-
ing. This was closed in 1894, and has not since been worked.
Recently Dr. Lucas has retired from the company, and the
mines are under the management of the new president, Mr. Frank
E. Bidwell. The force employed in the company's x^orth Carolina
mines has been somewhat variable, but it is usually about thirty
or forty. The company (now styled the Hampden Emery and
Corundum Company) also owns the Buck creek mine, but has not
yet attempted to work it ; also the Pine Mountain mine, (Laurel
creek,) in Rabun county, Georgia, which was operated from 18 SO
till the spring of 1893 ; and the emery mine at Chester, Massa-
chusetts, which is still in operation.
d. THK SAPPHIRE (HOGBACK) MINKS, JACKSON COUNTY.
Corundum was known in the vicinity of Great Hogback moun-
tain in the southeastern corner of Jackson county atthe time when
Dr. Smith wrote his report on this region, 1875.* He speaks of
several hundred pounds having been taken out by digging small
pits.
Work was begun here by the Sapphire Valley Mining Company
in 1892, at the " Burnt Bock " mine, seven miles northeast of
Sapphire ; and shortly afterwards a number of places in the sur-
rounding country were opened. A complete cleaning and crushing
plant was erected on Horsepasture river, and considerable expense
was incurred in building roads, bridges, stores and other houses,
saw-mills, shops, etc. About fifty or sixty men were constantly
employed in mining, prospecting, and improvements, during the
year in which the mine was operated. Mr. Charles N". Jenks, the
superintendent, reports a product of over 400 tons, one-fourth of
which was crystal corundum 90 per cent. pure. Work was sus-
*Rept. Geol. Sur. N. C, 1, 1875, Appendix 91-97.
NORTH CAROLINA CORUNDUM MINES. 95
pended during the financial crisis of 1893, and has not yet been
resumed. The new railroad to Brevard will affect a considerable
saving in transportation, as the product was formerly hauled on
wagons to Henderson ville for shipment, a distance of some forty
miles. (For descriptions of the various workings, see pages 71
and 72.)
e. THE CARTER MINE MADISON COUNTY.
This mine is in the eastern corner of the county, near Demo-
crat postoffice, in Buncombe county. It is located on Holcombe
branch, a tributary to Ivy river, and marks the northern extremity
of the belt of dunite which extends over a distance of more than
two miles, with an average width of about one-fourth of a mile.
Dr. C. D. Smith first found corundum here about fifteen or twenty
years ago.
The first work was done by Mr. William Carter and Dr. H. S.
Lucas, who took out a few tons in prospecting. Afterward work
of a similar nature was done by Mr. M. E. Carter, and by Messrs.
Rice and Coleman, who sold the property to Tarr, Hamilton and
Company, of ISTew York. This company began regular mining
about 1886. A steam crushing and sizing plant was erected on
the grounds, and about twenty tons of corundum were cleaned and
shipped from Marshall. The work continued only about six
months, and has not since been resumed. (See also page 74.)
/. THE ACME MINE, STATESVILLE, IREDEEE COUNTY.
This mine is located about three-fourths of a mile west of the
town of Statesville, and half a mile south of the Charlotte and
Taylors ville Railroad. About 1875, Mr. J. A. D. Stevenson
found corundum near the site of the present operations. The
Acme Corundum and Mining Company began work here in Feb-
ruary 1893 under the management of Mr. H. A. Collins. Some
corundum was shipped in the form of large rough blocks and
crystals, just as it came from the mine ; but this was soon found
unprofitable, and a steam mill was erected in March of the same
year for cleaning and crushing. The product of cleaned material
in 1893 was about fifty tons.
Considerable difficulty was encountered on account of the great
96 CORUNDUM AND BASIC MAGNESIAN BOCKS.
depth of soil and decayed rock. The mine is situated in a depression
near the head of a small branch, where the alluvial deposits of clay
are about fifteen feet deep. This material and the soft rock under-
lying it are so thoroughly saturated with water that great diffi-
culty was experienced in holding them back out of the workings.
Mining was resumed in December, 189i, and since then, the
work has been of the nature of prospecting for the purpose of
locating veins under more favorable conditions.
The mode of occurrence of this corundum and that of the Hun-
ter place, in Iredell, are described under the head of corundum
in amphibolite, pages 58 and 59. See also page 76.
8. OTHER ECONOMIC MINERALS OF THE CORUNDUM BELT.
Incidentally the chromic iron and asbestos deposits were noted
in passing over the region on the corundum work. These min-
erals have been found in promising abundance in many places, and
hence a word in regard to them is appended here. "While the cor-
undum shows a great falling off northward, this is by no means
true of the characteristic accompaniments of peridotite — chromite,
asbestos, and nickel silicates.
(1) CHEOMITE, OB CHBOMIC IEON.
This mineral has been found in considerable abundance in Jack-
son county, near Webster; in Bum combe county, at Morgan Hill;
and in several localities in Yancey, Mitchell, and Watauga coun-
ties. For analyses and more definite information, the reader is
referred to Bulletin No. 1 of the present Survey, Iron Ores of
North Carolina, by H. B. C. Nitze, 1893, pages 212-215.
(2) ASBESTOS.
A fibrous mineral which is called by this name has been the
object of considerable interest in Jackson county, in the vicinity
of Glenville; in Mitchell county, near Bakersville, and near the
mouth of Squirrel creek on north Toe river; in Watauga county,
NICKEL-BEARING MINERALS SERPENTINE. 97
along the western slopes of Rich mountain; in Ashe county, on
Elk creek; and it is found with all the enstatite rocks of the north-
eastern portion of this belt. Fibre of good length, color, and fine-
ness has been found in many places; and the mineral is of suffi-
cient importance to warrant further investigation. In some places
this fibrous mineral is enstatite, while in others it is chrysotile, or
fibrous serpentine. In a few cases it is possibly amphibole, the
true asbestos.
(3) NICKEL-BEARING MINERALS.
Minute quantities of nickel are often present in the olivine rocks
of this belt, but its presence can scarcely be detected in the fresh
specimen except by chemical methods. But when the olivine
begins to decompose under the influence of the atmospheric agen-
cies, it is readily seen in the characteristic green silicates that are
developed along the joints and fissures. Genthite, garnierite, and
perhaps other nickel silicates are formed in such relations in the
dunite at Webster, in Jackson county. These minerals have attrac-
ted considerable attention, and some prospecting has been done,
but nothing of importance as an ore has yet been found.
Similar indications of the presence of nickel were observed south
of Shooting creek, near Elf, Clay county, and south of Democrat,
in Buncombe county. Small amounts of nickel staining have been
seen in many places, showing a wide distribution of the metal in
our olivine rocks; but no other localities were found that are
considered worthy of special mention.
(4) SERPENTINE.
Mention has already been made (page 31) of the adaptation of
the serpentines of this belt to architectural purposes. They are
indentical in every respect with those of Maryland and Pennsyl-
vania, which are largely quarried, especially in the latter state, for
both interior decorative work and ordinary building purposes.
The dark green and mottled varieties take a fine polish and
give very rich effects for ornamental work where not exposed to
wear or weather. The peculiar, but not unpleasing effect of the
98 CORUNDUM AND BASIC MAGNESIAN ROCKS.
lighter colors for general building purposes may be seen in many
structures in Philadelphia, Baltimore, and Washington.
Outcrops of serpentine well suited to both these uses occur abun-
dantly between Weaverville aud Leicester, in Buncombe county,
in the strip that crosses the French Broad river a mile above Alex-
ander. Other masses equally as large are found on the Paint Fork
of Ivy river, in Madison county, and on the waters of Bald creek,
in Yancey county; but these are not so conveniently located for
transportation.
There seems to be no reason why the Buncombe county serpen-
tine should not come into the market in the near future. The era
of substantial building has only just begun in the southern states,
and as we learn to build, we should also learn to appreciate and
appropriate our own resources.
.
LITERATURE ON THE CORUNDUM BELT. 99
9. LITERATURE ON THE CORUNDUM BELT.
Only references pertaining to corundum itself or the corundum-bearing
rocks are included in this list. Many others on peridotites and serpentine
might be added.
Adams, J. H. Corundum at Pelham, Mass. Am. Jour. Science, 2, XLIX.,
1870, 271, 272.
Beck, Lewis C. Corundum in New York. Mineralogy of New York,
1842, 315.
Blake, W. P. Corundum, etc., at Vernon, N. J. Am. Jour. Science, 2,
XIII, 1852, 116.
Chatard, T. M. Corundum and emery of the U. S. Min. Resources of
the U. S., 1883-84, 714-720.
Gneiss-Dunite contacts of Corundum Hill, N. C. Bull. 42, U. S. Geol.
Survey, 1887, 45-63.
Cleaveland, Parker. Corundum at Litchfield, Conn. Mineralogy and
Geology, Boston, 1822.
Dana, J. D. Emery of Cortlandt, Westchester county, N. Y. Am. Jour.
Science, 3, XX., 1880, 199, 200.
Day, David T. Coruudum and emery of the U. S. Min. Resources of
the U. S., 1885, 429 : 1887, 553, 554; 1888, 577; 1889-90, 457.
Dickson, John. Corundum from the Carolinas. Am. Jour. Science, 1,
III., 1821, 4, 229, 230.
Fowler, Samuel. Sapphire, etc., at Newton, Sussex county, N. J. Am.
Jour. Science, 1, XXL, 1832, 319, 320.
Gannett, Henry. Corundum and emery of the U. S. Min. Resources of
the U. S., 1882, 476, 477.
Genth, F. A. Corundum in N. C. Jour. Franklin Inst., Nov. and Dec.
1871.
Corundum, alterations and associated minerals. Proc. Am. Phil. Soc,
XIII., 1873, 361-406 ; XIV., 1874, 216-218 ; XX., 1882, 381-404.
Corundum in Pennsylvania. 2nd Geol. Survey of Penn., B, 1875, 31-33.
Corundum in N. C. Rept. Geol. Survey of N. C, I., 1875, Appendix, 64.
— — and W. C. Kerr. Emery in Guilford county, N. C. Rept. Geol. Sur-
vey of N. C, I., 1875, 246.
Corundum in Patrick county, Va. Am. Jour. Science, 3, XXXIX.,
1890, 47, 48.
Corundum in N. C. Bull. 74, U. S. Geol. Survey, 1891, 29-31.
Hitchcock, Edward. Corundum at Litchfield, Conn. Am. Jour.
Science, 1, VI., 1823, 219.
Hunt, T. Sterry. On Dr. Genth's researches on Corundum. Proc. Nat.
Hist. Soc, Boston, XVI., 1874.
Hunter, C. L. Corundum and emery in Gaston county, N. C. Am.
Jour. Science, 2, XV., 1853,376.
100 CORUNDUM AND BASIC MAGNESIAN ROCKS.
Jackson, C. T. Discovery of emery at Chester, Mass. Am. Jour. Science,
2, XXXIX, 1865, 87-90.
Discovery of corundum at the emery mine, Chester, Mass. Am. Jour.
Science, 2, XLII., 1866, 421.
Jenks, Charles N. Abrasives in common use. Scientific American
Sup., No. 988, Dec. 8, 1894.
Jenks, C. W. Corundum in N. C, Am. Jour. Science, 3, III, 1873, 301,
302. Quar. Jour. Geol. Soc, London, XXX., 1874, 303-306.
Julien, A. A. Dunite beds of N. C, Proc. Nat. Hist. Soc. Boston, XXII.,
1882, 141-149.
Kerr, W. C. Corundum of N. C, Kept. Geol. Survey of N C, I., 1875,
299. Appendix Rept.Beol. Sur. of N C, 1873, 9.
King, Francis P. Corundum in Gra., Bull. 2, Geol. Survey of Ga., 1894.
Kunz. George F. Corundum gems of the U. S. Min. Resources of the U. S.,
1882, 485, 486; 1883-84, 733-736; 1892, 760-761; 1893, 680. Gems and Pre-
cious Stones of North America, 1890, 40-48.
Lesley, J. P. Origin of Corundum, etc., in Penn., 2d Geol. Survey of
Penn., C4, 1883, 351-354.
Lewis, J. Volney. Origin of peridotite and Corundum of the southern
Appalachians. Jour. Elisha Mitchell Sci. Soc, 12th year, 1895-6.
Corundum of the Appalachian Crystalline Belt. Trans. Am. Inst.,
Min. Eng., XXV., Atlanta meeting, 1895.
Paret, T. Dunkin. Emery and other abrasives. Jour. Franklin Inst.,
CXXXVIL, 1894, 353-372, 421-438.
Parker, E. W. Corundum of the U. S. Min. Resources of the U. S.,
1891, 555; 1892, 751.
Corundum in N. C. Min. Resources of the U. S., 1893, 674 678.
Pennypacker, Charles H. Corundum in Penn. Mineral Collector, II..
1895, 89, 90.
Raborg, William A. Corundum of the U. S. Mineral Resources of the
U. S., 1886, 585, 586.
Rand, Theodore D., W. W. Jefferis, and J. T. M. Cardeza. Min-
eral localities of Philadelphia and vicinity. Proc. Ac. Nat. Sci.
Phil., 1892, 174-202.
Origin of serpentine of Pennsylvania. Proc. Ac. Nat. Sci. Phil., 1890,
76-123.
Raymond, R. W. Jenks (Corundum Hill) mine, N. C. Trans. Am. Inst.
Min. Eng. VII., 1878, 83-90.
Shepard, C. U. Corundum at Litchfield, Conn. Minerals of Conn., 1837,
64.
Corundum regions of N. C. and Gra. Am. Jour. Science, 3, IV.. 1872,
109-114, 175-180.
LITERATURE ON THE CORUNDUM BELT. 101
Emery and associated minerals at Chester, Mass. Am. Jour. Science,
2, XL., 1865, 112, 123; 2, XLIL, 1866, 421, 422; 2, XLVL, 1868, 256.
Silliman B., Jr. Corundum and associated minerals, Unionville, Penn.
Am. Jour. Science, 2, VIII., 1849, 377, 393.
Smith, C. D. Corundum in N. C. Rept. Qeol. Survey of N. C, I, 1875,
Appendix, 91-97; 98-120.
Smith, Edgar F. Discovery of corundum in Lehigh county, Penn. Proc.
Am. Phil. Soc, XXII., March, 1882.
Analysis of corundum from Lehigh county, Penn. Am. Chem. Jour.
V., 1883, 275.
Smith, J. L. Emery of Chester, Mass. Am. Jour. Science, 2, XLIL, 1866,
83-93.
Corundum in N. C, Ga. and Mont. Am. Jour. Science, 3, VI., 1873,
180-186.
Trautwine, J. C. Corundum, etc., Cullasaja (Corundum Hill), N. C,
Jour. Franklin Inst, XCIV., 1872, 7.
Wadsworth, M. E. Olivine rocks of N. C, Science, III., 1884, 486, 487.
Dunite of N. C. uLithological Studies,'''1 Mem. Mus. Comp. Zool., Cam-
bridge, XL, Part 1, 1884, 118-120.
Willcox, Joseph. Corundum in North and South Carolina. Proc. Acad.
Nat. Sci. Phil., 1878, 159, 223.
Corundum in Penn. 2d Qeol. Survey of Penn., C4. 1883, 346-351.
Williams, G. H. Emery of the " Cortland series," N. Y. Am. Jour.
Science, 3, XXXIII, 1887, 194-199.
Miscellaneous mention. — Corundum in N. J. Am. Jour. Science, 1, XIIL,
1828, 380.
Corundum Hill, N. C. Am. Jour. Science, 3, III., 1872, 301.
Corundum in N. C. Pop. Science Monthly, IV., 1874, 452-456.
Corundum in S. C. Agr. Rept. S. C. 1883, 137, and map.
Corundum in Ga. The Commonwealth of Ga., 1885, 139.
102 CORUNDUM AND BASIC MAGNESIAX ROCKS.
EXPLANATION OF PLATE YI.
PHOTOMICROGRAPHS OF THIN SECTIONS OF DUNITE.
Photographed with Fetiss'' objective No. 0. Magnified 12 diameters.
FIGURE 1. — RAIUROAD CUT 2 M. WEST OF BALSAM GAP, JACKSON COUNTY.
This is an exceptionally fresh specimen of the pure olivine type. The
perfectly crystalline, even grained texture of the rock, and the generally
irregular (hypidiomorphic) structure are well shown ; though crystal out-
lines, like that on the upper left hand side, are frequently seen.
FIGURE 2. — CARTER CORUNDUM MINE, MADISON COUNTY.
This figure represents the prevailing character of the surface exposure
of dunite. These first narrow bands of yellowish green serpentine formed
about the borders of the olivine grains are minutely fibrous, with the
fibres at right angles to the boundaries of the olivine. They look very
much like mortar in rubble masonry.
FIGURE 3. — CARTER CORUNDUM MINE, MADISON COUNTY.
This section shows a common type of fine grained olivine rock as seen
between crossed nicols (polarized light). The minute grains are found to
extinguish together over considerable areas, showing that the fine text-
ure is the result of irregular cracking up of large grains similar to those
shown in figure 1.
FIGURE 4. — WEBSTER, JACKSON COUNTY.
This specimen shows an advanced stage in the alteration of olivine to
serpentine, the beginning of which was seen in figure 2. In the process of
alteration, a considerable proportion of magnetite has been formed and
deposited in dark bands about the olivine remnants, which appear white
in the figure.
FIGURE 5. — PAINT FORK OF IVY RIVER, MADISON COUNTY.
Here we have the final result of the process of serpentinization repre-
sented in figures 2 and 4. No trace of unaltered olivine remains. The
positions of the last fragments to disappear are marked by black accumu-
lations of magnetite; otherwise the serpentine appears quite homogeneous
in ordinary light.
FIGURE 6. — SAME AS FIGURE 5.
The subject of this figure is identical with the last, except that the
section is here viewed between crossed nicols. The network of light
bands ("mesh-structure") represents the first serpentine formed in the
alteration of olivine, as shown in figure 2, and marks the boundaries of
the original grains. (This figure is inverted with reference to figure 5.)
N. C. GEOLOGICAL SURVEY.
BULLETIN 11. PLATE VI.
THIN SECTIONS OF DUNITE. (Magnified 12 Diameters'.
INDEX.
Acme corundum mine, Iredell Co.
Actinolite in amphibolite
in anaphibole-picrite....
in dunite
in talc
Adams, F. D., cited
Adams, J. EL, cited
Addie, Jackson Co., corundum
peridotite
PAGE.
95
23
Alabama, corumdum 38,64
peridotite 33, 64
Alexander, Buncombe Co., serpen-
tine 41, 98
Alexander Co., corundum 76, 89
Alleghany Co., peridotite 47
soapstone 47
Alluvial deposits, corundum in 62
Alterations of dunite 20, 56, 102
of peridotite 20,56
of pyroxenite 26
Amphibole 20, 23, 25, 26, 59, 60
Amphibole-picrite 23
Amphibolite 28, 58
Analyses of enstatite 27
of emery, Guilford Co 78
of feldspar in f orellenstein 24
of "smaragdite" 29
Andalusite 61
Anorthite in amphibolite.. 28, 58
in forellenstein 24
Anthophyllite 26, 56
Apophyses of peridotite 36, 38
Appalachian crystalline belt 12,33
Asbestos 45, 69, 73, 96
Ashe County 97
Jackson " 96
Mitchell " 45, 75, 96
Watauga" 45,96
Ashe Co., asbestos 97
peridotite 46
soapstone 32, 47
Asia Minor, emery 88
Asteria, asteriated sapphire 50, 52
Bakersville, asbestos 96
corundum 75
peridotite 44
Bailey, John and Joel, corundum in
Penn .-. 87
Balsam Gap, peridotite 38
Banks creek, peridotite 43
Baskerville, Dr. Chas., analyses by. 24, 26, 29
Beck, Lewis C, cited 88
PAGE.
Behr corundum mine, Clay Co 91
Bell knob, peridotite 35
Bellevue, peridotite 45
Bid well, Frank E., corundum mining 94
Blake, W. P., cited 88
Block corundum 52
Boone, Watauga Co., chromite 19, 96
peridotite 45
Bowman, D. A., cited 75
Bowman, Wm., corundum 75
Brace, John P., cited 87
Brush creek, peridotite 47
Bryson, Major, corundum mining.... 91
Buck creek, amphibole-picrite 24
amphibolite 28, 36, 55
corundum mine 69, 83, 91
forellenstein 24, 36
peridotite 15, 34, 36
serpentine 30
Buncombe Co., chromite : 96
corundum 73
nickel-bearing min-
erals 40
peridotite 40
serpentine 30, 40
Burke Co., corundum 63, 77
Burnsville, chromite 19, 43
Cane creek, Jackson Co., peridotite.
websterite
Cane creek, Mitchell Co., peridotite..
Caney fork, corundum
Cai'bonates in dunite 21,
Carpenters knob, corundum
Carter, John A., acknowledgements
corundum
Carter corundum mine, Madison Co. 41, 74,
Chalcedony from peridotite 22,
Chatard, T. M., cited
Chatham Co., corundum
Cherokee Co., corundum
Chester, Mass., emery mine tit;, 80,
Chestnut mountain, dunite
Chlorite
in amphibole-picrite
in dunite 20, 21,
veins of with corundum 55,
Chlorite schist
corundum in 33,
Chloritoid
Chromite, chromic iron 19.
in peridotite 17, 18,
relation to picotite
104:
INDEX.
Chrysolite, see Olivine.
Chrysotile 97
Chubbs mountain, corundum 77
Chunky Gal mountain, corundum-... 62, 68
peridotite 35
Clay Co., corundum 67,91
nickel-bearing minerals.... 97
peridotite 24, a5
Cleaning corundum, methods 81, 83
Cleveland Co., corundum 77
Cleveland, Parker, cite i 87
Clingman, Gen. T. C, 88
Collins, H. A., corundum mining 95
Commercial corundum 50, 52
Concentration of corundum 81
natural 62
Connecticut, corundum 66
Corundum, character and varieties. 48
in North Carolina. 51
as rock constituent 54
cleaning processes 81, 83
discoveries and early de-
velopments 87
distribution 63
in Alabama 33,64
Alexander Co.. 76,89
Appalachian belt 63
Buncombe Co 73
Burke Co 63,77
Chatham Co 78
Cherokee Co 78
Clay Co 67,91
Cleveland Co. 77
Connecticut 66
Forsyth Co 78
Gaston C > 77,88
Georgia 33, 64
Guilford Co 77, 89
Haywood Co 73
Iredell Co 58,76,89,95
Jackson Co 57, 63, 70
Macon Co 69,92
Madison Co 74, 88, 95
Massachusetts 34, 66
Mitchell Co 75
New Jersey 65, 88
New York 34, 66 ,88
North Carolina. 33, 64, 67, 88
Pennsylvania 33,65
Polk Co 78
South Carolina 33, 64
Transylvania Co 72
Virginia 65
Wilkes Co 78
Yancey Co 75
mining methods 81,82
modes of occurrence 54, 93
page.
Corundum— Continued.
prospecting methods 78
uses of 51
Corundum belt, geologic sketch 11
Corundum gems 50. 52
Corundum Hill mine 37, 92
cleaning methods.... 85
Corundum mining, historical sketch 86
in North Carolina 89
methods of 81,82
Corundum wheels 51
Cowee mountains, corundum 70
Crab creek, peridotite 47
Cranberry, peridotite near 45
Crisp, Hiram, discovery of corundum 88
Crowders mountain, corundum 77
Cullakanee mine, see Buck Creek.
Cullasaja mine, see Corundum Hill.
Cyanite, corundum in 61, 73, 74.87
Damourite on corundum 76
Dana, James I)., cited 28.50
Delafleld, Maj., cited 87
Democrat, corundum near 73
nickel-bearing minerals. 41, 97
peridotite 40
Deer Island, Me., serpentine 34
Diallage in dunite 19
Diaspore with corundum 56. 88
Dickson, John, chW 87
Dikes of amphibolite 28
hypersthenite 61
Discoveries and developments of
corundum 87
Distribution of peridotite, ere. 33
of corundum, see Co-
rundum.
Dunite 17, 43
alteration of 20,56,102
corundum in 60. 75
distribution, see Peridotite.
microscopic characters 18. 102
Economic minerals of corundum belt 96
Edenite 28
Egypt (Hayes) mine, Yancey Co 44, 75
Elf, Clay Co., corundum 68, 91
nickel-bearing minerals... 97
peridotite. 35
Elk creek, Ashe Co., harzburgite 46
Elk ridge, Ashe Co., peridotite 47
Emerson, B. K., cited 67
Emery 11, 50, 88
Chester, Mass. 66, 80
Forsyth Co 78
Gaston Co ". 88
Guilford Co 77,89
;";.•-. -. -
INDEX.
105
PAGE.
Emery— Continued.
New York 34,66
Emery wheels 51
Ennis, Alleghany Co., peridotite 47
Enstatite in peridotites 19, 23, 25, 47
in pyroxenites.. 25
Enstatite borders 21, 56
Enstatite rock. 25, 45, 46
analyses of.... 27
Feldspar in amphibolite 29
in forellenstein 24
with corundum 59, 74, 76, 83
Fish Hawk mountain, corundum 69
Flat creek mountains, peridotite 41
Forellenstein, troctolite 24, 35
Forsyth Co., corundum and emery... 78
Fowler, Dr. Samuel, cited 87
French Broad river, peridotite 39, 42
serpentine 31, 41, 98
Friendship, emery near 77
Garnet 46, 62, 73
Garnierite 97
Gaston Co., corundum... 77, 88
Gem varieties of corundum 50,51
Genth, Dr. F. A., cited. 10, 27, 28, 56, 61, 77, 78, 89
Genthite 97
Geologic sketch of corundum region 11
Georgia, corundum in 33, 64
peridotite 34, 36, 39
Glade creek, peridotite 47
Glenville, Jackson Co., asbestos 96
peridotite 39
Gneiss, corundum in 61, 73
of the crystalline belt 12, 55
Gravel deposits, corundum in 62
Grimshawe, Dr. C, acknowledge-
ments 91
Guilford Co., emery 77, 89
Hamilton corundum mine, Georgia. 35
Hampden Emery and Corundum Co. 92, 94
Hart, Gregory, corundum mining.... 91
Harzburgite (Saxonite) 23, 43, 46, 47
Hayes (Egypt) mine, Yancey Co.... 44, 75
Hayes, U. S., acknowledgements 91
Haynie, G. C, corundum 75
Haywood Co., corundum 73
peridotite 40
Historical sketch of corundum m'n'g 86
Hitchcock, Edward, cited 66, 87
Hoboken, N. J., serpentine 34
Hogback (Sapphire) corund1m mine 39, 71, 94
Hogsed, Samuel, corundum 68
7
PAGE.
Hornblende, see Amphibole.
" Hosea Moses Mine," Macon Co 94
Hunter, Dr. C. L., cited 77, 88
Hypersthenite dikes 61
Igneous rocks, sheared 12
"Indications" of corundum 78
Iredell Co., amphibolite 58
corundum 58,76,89,95
Ivy river, corundum 75, 95
peridotite 42
serpentine 31,42, 98
Jackson Co., asbestos 96
chromite 19, 96
corundum 57, 63* 70, 94
nickel-bearing min'r'ls 97
peridotite 37
Jackson, Dr. C. T., cited 88
Jefferis, W. W., cited 87
Jefferson, soapstone 47
Jenks, Chas. N., acknowledgements 71. 90, 94
Jenks, Col. C. W., corundum mining. 89, 92
Julian, Frank, analysis by 27
Julien, A. A., cited .. 10
Kings mountain, corundum 77
King, Francis P., cited 26,28,35, 65
Kunz, George F., cited . 51,52,64
Laurel creek (Pine mountain) co-
rundum mine, Georgia 39, 64, 83
Leicester, serpentine 40, 98
Lewis, J. Volney, cited 31
Limestone, corundum with 66, 88
Literature on corundum belt. 99
Litchfield, Conn., corundum 87
Lucas, Dr. H. S., acknowledgements 88, 90
corundum mining 91, 93, 95
McChristian place, emery 77
McDowell Co., corundum 63
Macon Co., corundum 37, 69,92
peridotite 36
Madison Co., corundum 74, 88, 95
peridotite 41
serpentine 30, 41, 98
Magnesian rocks 13,15
Magnetite 21, 46, 102
Maine, serpentine 34
Map of Appalachian crystalline belt 32
Buck creek peridotite area... 34
Corundum Hill 36
Webster peridotite area 38
Western N. C. Frontispiece.
106
INDEX.
PAGE.
Margarite with corundum. 56, 59, 73, 76, 80, 88
Marshall, corundum discovery 74, 88
Maryland, corundum 65
serpentine 31, 33, 97
Massachusetts, corundum, emery ...66, 88, 89
peridotite 34,67
serpentine 34
Massive rocks of peridotite belt 13, 15
Meminger, Frank, mining 91
Mesh structure of serpentine 102
Methods of cleaning corundum 81, 83
mining 81, 82
prospecting 78
Mica with corundum 56.58,60, 61
Mica schist, corundum in 61, 64, 73
Microscopic characters of dunite 18, 102
serpentine 102
Mining and cleaning methods 81
Mitchell Co., asbestos 45, 75, 96
chromite 96
corundum 75
peridotite 44
Modes ofoccurrence of corundum.... 54, 93
Monazite 77
Morgan Hill, chromite £6
Muscovite 58,58,60,61
New Found creek, serpentine 40
New Found gap, corundum 73
peridotite 40
New Hampshire, serpentine 34
New Jersey, corundum 87, 88
serpentine 34
New York, corundum and emery... 34, 66, 88
peridotite 34, 66
serpentine 34
New Zealand, dunite 17
Nickel-bearing minerals 22, 44, 97
Nitze, H. B. C, acknowledgements . 77
cited 96
North Toe river, asbestos 96
peridotite 45
Norwich, Conn., corundum 66
Ocoee formation 14, 45
Olivine, alterations, etc 20, 102
in forellenstein : 24
in peridotite 15
serpentine from 30, 102
Oriental amethyst 50
emerald 50
ruby 50, 52
topaz 50
Paint Fork of Ivy river, serpentine. 42, 98
Paleozoic of Tennessee 14
Pegmatite with corundum 57, 73
PAGE.
Penland, Newton, corundum 68
Pennsylvania, corundum 33, 65
serpentine 31. 33
" Perido-steatite " 42, 44
Peridotite and associated rocks 13, 15
corundum with 55
distribution'in Alabama 33, 64
Alleghany^Co 47
Appalachian belt 33
Ashe Co 46
Buncombe Co 40
Clay Co 35
Georgia 33, 36, 39, 64
Haywood Co 40
Jackson Co 37
Macon Co 36
Maine 34
Madison Co 41
Maryland 33. 97
Massachusetts 34. 67
Mitchell Co 44
New Hampshire 34
New Jersey 34,66
New York 34,66
North Carolina 34, 64, 67
Pennsylvania 33, 65
South Carolina 33. 64
Transylvania Co 39
Vermont 31
Virginia 33, 65
Watauga Co 45
Yancey Co 43
Picotite in amphibole-picrite 23
amphibolite 29, 58
dunite 17. 18
relation to chromite 18
Pigeon river, corundum 73
Pine mountain (Laurel creek) corun-
dum mine, Georgia 39. 64. 83
Pine Swamp creek, peridotite 47
Polk Co., corundum 78
Presley corundum mine, Hayw'd Co. 40, 73
Prices creek, peridotite. 43
Prospecting methods 78
Pyrite with corundum 87
Pyrophyllite, corundum in 78
Pyroxene 56
in harzburgite 23
in pyroxenites 25,27
Pyroxenites 25, 45, 46
Rabun Co., Georgia, corundum 39
peridotite 36
Reaction zones in forellenstein 25
Rich mountain, chromite 45
peridotite 45
Ropes, L. S., acknowledgements 91
INDEX.
107
PAGE.
Ruby, oriental or true 50, 52
Rutherford Co., corundum 63
Sampson mountains, corundum 75
peridotite 44
Sand corundum 52
Sapphire 50
Sapphire (Hogback) mine 39, 71, 83, 94
cleaning methods 84
Saxonite (Harzbui gite) 23, 43, 46, 47
Scaly mountain, corundum 69
Schistose magnesian rocks 32
Seal, Dr. Thomas, corundum in Penn 87
Secondary minerals in dunite 20
Secondary magnesian rocks 30
Serpentine..... 20,30, 97
architectural uses 31, 97
derived from olivine 20, 30
distribution, Buck creek 30
Buncombe Co 30, 40
Clay Co 30
Madison Co 30
Maine 34
Maryland 31,33,97
Massachusetts 34
New Hampshire.. 34
New Jersey 34
New York 34
Pennsylvania 31, 33, 97
Vermont 34
Virginia 33
Watauga Co 46
Yancey Co 30
Sheared igneous rocks 12
Shepard, Dr. C. IT., cited 10
Shooting creek, corundum 61, 68, 91
nickel-bearing'minerals.. 97
peridotite 24, 35
Smaragdite 28
Smith, Dr. C. D., cited 26,60,91,94
Smith, Dr. J. L., cited 88
Soapstone, talc rocks 32, 42
Alleghany Co 32
Ashe Co 32, 47
Watauga Co 46
South Carolina, corundum 33,64
South Toe river, peridotite 44
Spinel with corundum . 56,66, 74
Star sapphire 50, 52
Staten Island, serpentine 34
Statesville, corundum 76, 95
Staurolite 56
PAGE.
Stephenson, J. A. D., acknowledge-
ments 89, 91
Stoner, A. M., acknowledgements.... 91
Swannanoa gap, corundum 74
Talc from enstatite 26
in dunite 21
Talc rocks, soapstone 13, 32, 42, 46, 73
Tourmaline with corundum 56
Towns Co., Georgia, corundum 34, 64
peridotite 34
Toxaway river, corundum 73
Track Rock corundum mine, Ga 34
Transylvania Co., corundum 72
peridotite 39
Tremolite in dunite 21
Troctolite, Forellenstein 24
Turkey knob, corundum 70
Union Co., Georgia, corundum 34
Uses of corundum 51
Varieties of corundum 48, 51
Vermiculite 57, 59, 76
Vermont, serpentine 34
Vernon, N. J., corundum 88
Virginia, corundum 61, 65
peridotite 47
serpentine 33
Wadsworth, Dr. M. E., cited, 19
Ward, E, B., corundum mining 89
Watauga Co., asbestos 45, 96
chromite 19, 96
peridotite 45
Weathering of dunite 22
Weaverville, serpentine 98
Webster, chromite 19,96
nickel-bearing minerals.... 97
peridotite 15,17, 34, 37
Websterite 27
Wilkes Co., corundum 87
Willcox, Joseph, cited 78
Williams, Dr. G. H., cited 9, 27, 66
Yancey Co., chromite 19, 96
corundum 75
peridotite 43
serpentine 30, 98
Zirkel, F., cited 54
HISTORY OF THE GEMS FOUND IN
NORTH CAROLINA
BY
GEORGE FREDERICK KUNZ, Ph.D.
I
i
NORTH CAROLINA GEOLOGICAL AND
ECONOMIC SURVEY
JOSEPH HYDE PRATT, STATE GEOLOGIST
BULLETIN NO. 12
HISTORY OF THE GEMS FOUND IN
NORTH CAROLINA
GEORGE FREDERICK KUNZ, Ph.D.
RALEIGH
E. M. Uzzell & Co., Public Printeks and Binders
1907
\
A
r
b'bl
/|/f/2>
4_
GEOLOGICAL BOARD
Governor R. B. Glenn, ex officio Chairman Raleigh.
Henry E. Fries Winston-Salem.
Frank R. Hewitt Asheville.
Hugh MacRae Wilmington.
Frank Wood Edenton.
Joseph Hyde Pratt, State Geologist Chapel Hill.
t
LETTER OF TRANSMITTAL
Chapel Hill, N. C., November 15, 1906.
To His Excellency, Hon. E. B. Glenn,
Governor of North Carolina.
Sir. — I have the honor to submit for publication as Bulletin No.
12 of the Geological and Economic Survey, the report of Dr. George
Frederick Kunz on the History of the Gems found in North Carolina.
Yours obediently,
Joseph Hyde Pratt,
State Geologist.
L
CONTENTS
PAGE
Peeface ix
Introduction xl
Chapter I. — Historical sketch of gem mining in North Carolina 1
II. — Diamonds 5
III. — Corundum gems 10
IV. — Gem minerals of the pegmatite dikes 25
The feldspars 27
Orthoclase 27
Microline 27
Oligoclase 27
Labradorite 28
Leopardite 28
V— Quartz 29
Crystalline varieties 29
Rock crystal 29
Amethyst 81
Smoky quartz 32
Rose quartz 33
Quartz inclusions 33
Fluid inclusions 34
Non-Crystalline quartz 35
Chalcedony 35
Chrysoprase 35
Jasper 35
Opal 36
Hyalite 36
VI. — Beryl, spodumene (hiddenite) 37
Beryl 37
Emerald beryl 37
Aquamarine 42
Yellow beryl 42
Hiddenite or lithia emerald 45
VII. — Garnet, zircon, rutile, octahedrite 49
Garnet 49
Almandite 49
Pyrope 50
Rhodolite 50
Zircon 51
Rutile 52
Octahedrite 53
VIII. — Cyanite, epidote, tourmaline, chrysolite (peridot), ser-
pentine, SMARAGDITE, LAZULITE, MALACHITE, PEARLS.. 54
Cyanite 54
Epidote 55
Tourmaline 55
Chrysolite (peridot) 56
Serpentine 56
Edenite (smaragdite) 57
Lazulite 57
Malachite 58
Pearls 58
ILLUSTRATIONS
PLATE FACING PAGE
I. Corundum gems from North Carolina « 1
II. Wiseman Beryl Mine, Mitchell County, N. C, 18 miles from
Marion 2
III. Diamond and heryl crystals from North Carolina 8
IV. A, Transparent blue and green sapphire, natural size, Macon
County, N. C; B, Corundum showing alteration, natural size,
Haywood County, N. C 16
V. Quartz gems from North Carolina 26
VI. A, Quartz crystals (smoky), natural size, Alexander County,
N. C; B, Amethyst crystals, Lincoln County, N. C 30
VII. A, Smoky quartz crystals 7/16 natural size, Hiddenite P. 0.,
Alexander County, N. C; B, Quartz crystals with amethyst
tips, natural size, Lincoln County, N. C 32
VIII. A, Group of quartz crystals, parallel crystallization, % natural
size, Lincoln County, N. C; B, Group quartz crystals en-
closing clay and water, % natural size, Burke County, N. C. 34
IX. Beryl crystals from North Carolina 38
X. Emerald mine, Crabtree Mountain, Mitchell County, N. C, about
25 miles from Marion 42
XL Beryl crystals, natural size, Burnsville, N. C 44
XII. A, Spodumene (hiddenite) in matrix, natural size, Stony Point,
N. C; B, Cyanite, natural size, Burnsville, N. C 48
XIII. Garnet and cyanite gems from North Carolina 50
XIV. A, Rutile crystals, natural size, Stony Point, N. C.;. B, Rutile,
reticulated, natural size, near Hiddenite P. 0., Alexander
County, N. C 52
XV. A, Rutile with dolomite and muscovite; B, Rutile group, natural
size, Stony Point, N. C 56
>
PREFACE
The preparation of the report on the History of the Gems Found in
North Carolina was turned over to Dr. George Frederick Kunz of New
York as the recognized authority on gems. He has had access to all the
information relating to gems and gem minerals on file in the office of the
Survey, and has also drawn freely from the various publications by
himself and others relating to the gems of the State. In his introduction,
Dr. Kunz calls attention to the fact that the production of gems in the
State has been largely incidental to the mining and production of some
other mineral and that there have been but few localities that have been
developed solely for gems. At the present time, however, there are
several companies operating in North Carolina simply for gem minerals,
the two more important companies being the United States Ruby Com-
pany and the American Gem and Pearl Company.
The report is freely illustrated and many of the colored illustrations
are of gems in the Morgan-Tiffany and Morgan-Bement collections at
the American Museum of Natural History of New York City.
Chapter I gives a brief historical sketch of gem mining in the State,
but detailed accounts are given in many instances under the head of the
individual mineral.
The various gem minerals are described in the next five chapters. The
localities are also given and reference is made to the commercial value of
the gem material found.
This report does not pretend to take up a detailed account of the
geological occurrences of the gem minerals, or a study of their chemical
and physical characteristics, as these will be discussed in a later publi-
cation. It has been published especially for distribution at the James-
town Exposition.
Joseph Hyde Pratt,
State Geologist.
>
INTRODUCTION
North Carolina, with its magnificent mountains and its swiftly running
rivers and streams, has now for some years come to possess almost as
great a charm for the Northern as it long before had for the Southern
tourist. " The land of the Sky " has become a favorite resort for the
traveler, the invalid, the sportsman, the lover of nature, and the seeker
for rest, from almost every part of the country. For the mineralogist,
too, it has peculiar interest, so great, indeed, that its scenic attractions
have, for such as he, been almost overmatched, not to say overlooked,
in the search for the beautiful crystals that are found in its mountains,
and the variety of rare, minute, and interesting minerals that occur in
the brooks and streams associated with gold. Among these crystals and
sands occur many minerals that have yielded true gems, and North
Carolina has hence become one of the most notable States for gem pro-
duction in the American Union.
The finding of these minerals, however, has been in most cases a
secondary or incidental result in the search for and mining of substances
more immediately desired for practical use on a larger scale. These
last have been essentially three, which have developed in succession, and
mark several stages in the mineral production of North Carolina.
These stages were : (I) The gold-mining, from early in the last century
to the time of the Civil War; (II) the corundum and mica industry, for
the quarter-century following that great struggle; and (III) the devel-
opment of the " rare earths," and the monazite sands, in connection with
recent scientific discoveries and appliances, within the last 10 or 15
years. To these may be added a fourth stage, viz., that of systematic
mining for the gems themselves at various times, such as for sapphire
at Corundum Hill; for ruby and rhodolite in the Cowee Valley; for
beryls in Mitchell County, and later, for amethyst at Tessentee Creek,
Macon County.
Through the gold belt of the western Carolinas and Georgia, that
metal occurs widely distributed, but in very variable amounts. At certain
points mining has been conducted with profit, and in some instances
nuggets of impressive size have been obtained. More or less active
working has long been done in the North Carolina gold fields, and the
Xll INTRODUCTION.
total product has been very considerable; but, strange as it may seem,
many of the discarded gold-washings of a century ago are now yielding
more to the owner of the land for the obscure and long unknown monazite
sands than for the gold originally obtained with them. In regard to this
latest development, extended mining has recently shown that the hillsides,
from which the monazite sands in the " branches " and streams originally
came, contain an endless store of these rare minerals, and that when the
ancient brook-washings are exhausted, the hillsides can be resorted to for
a century to come. It is in the search for this mineral that most of the
small and beautiful garnets, rutiles, sapphires, epidotes, and other gems
have lately been found.
Between the gold-mining of earlier times and the more recent and
varied developments, came the terrible years of the " war between the
States." When that was past, brave and patriotic men like the late
Gen. Thomas L. Clingman, afterwards United States Senator, turned their
attention to developing the natural resources of their State and retrieving
in every way possible the ruin and devastation that had swept over the
South. Then commenced a period of exploration and discovery in the
mineral and gem treasures of North Carolina that has progressed and
expanded to a wonderful extent. It began with the corundum industry
and the mica mines. The presence of the former mineral had been known
for some years before the war, but it had not been developed. The first
notice of its occurrence in the State was in 1846, by Prof. C. D. Smith,
but with no particulars as to the locality. About 1850 General Clingman
announced it from Madison County; andin 1852, Prof. E. T. Brumby,
of the College of South Carolina, collected and labelled specimens from
Clubb Mountain, in Lincoln County, and placed them in the College cab-
inet at Columbia, S. C. In the next year Professor Ebenezer Emmons, of
the University of North Carolina, in a report on the midland counties of
the State, mentioned a discovery of corundum by Dr. C. L. Hunter, in
Gaston County. Little or nothing was done in regard to it, however, until
immediately after the war, in 1865, when the Rev. C. D. Smith, of Frank-
lin, Macon County, who had been an assistant to Prof. Ebenezer Emmons
on the Geological Survey of the State, identified specimens that were
brought to him, visited the spot whence they came, and discovered a
number of important localities. In the next 5 years a great amount of
exploration was done, mines were opened, and an important and enduring
industry was called into being. Among those most active in this field
of study and progress, besides Mr. Smith and General Clingman, were the
able State Geologist, Prof. Washington C. Kerr, the enthusiastic and
indefatigable collector, Mr. J. Adlai D. Stephenson, of Statesville, and
INTRODUCTION". Xlll
Mr. C. W. Jenks, who opened the Corundum Hill mine, at Franklin, N. C,
about 1870, and was the first to find gem sapphire in its original matrix.
During the same period, numerous valuable scientific reports and analyses
were prepared and published by such authorities as Prof. F. A. Genth,
Dr. J. Lawrence Smith, and Dr. T. M. Chatard; and the North Carolina
corundum, its history, mineralogy, and composition, was thus made widely
known.
Although the main value of the mineral as mined was for use as an
abrasive material, yet pieces were obtained that had color and transparency
enough to rank them in some cases as true gems and largely as valuable
specimens. Among the first fine crystals were some obtained by Prof.
C. U. Shepard; one of these, now in the Shepard collection at Amherst
College, Mass., weighs over 300 pounds. Besides the collecting tours of
Professor Shepard, many annual visits were made to the corundum region
by Mr. Norman Spang, of Pittsburg, Pa., a wealthy and noted collector,
who encouraged exploration, and brought back with him much of the
choicest of the "treasure trove." Mr. W. E. Hidden, of New York,
devoted a large part of 20 years to energetic and intelligent search
for minerals and gems with wonderful success; and recently the State
Geologist, Dr. Joseph H. Pratt, and Prof. J. V. Lewis have given ex-
tended and detailed study to the whole subject of the various occurrences
of corundum in the State. All this activity has not only developed the
industry itself, but has led incidentally to other discoveries. It may be,
indeed, that more has been spent in the search and in attempts at mining,
not always judicious, than the product itself has yielded; but the effect
on the development of the State has been immense. In the matter of
gems and remarkable specimens, these years of exploration have succes-
sively brought to light one and another fine gem, crystal, or rare mineral,
to such an extent that to-day, were the North Carolina specimens removed
from the great collections of the world, a gap would be left that could
not be filled, in such places as the American Museum of Natural History,
New York, the British Museum of London, the Imperial Museum of
Vienna, the U. S. National Museum at Washington, the Field Columbian
Museum of Chicago, the Musee de Historie Naturelle, Paris; and many
others, important but less famous.
During the same general period, the mining of mica came to be another
important industry in the revival of the State, and this also led to
discoveries of other rare minerals in the search for valuable localities for
mica. One of the most curious and interesting facts brought to light in
this connection, was the clear evidence that some of the best mica mines
had been long and extensively worked by ancient aborigines, either Indians
XIV INTRODUCTION.
or earlier "mound-builders" (if these indeed be distinct peoples), or
both. Ornaments cut from mica, as also shells and quartz crystals, are
not uncommon in the burial-mounds of the Mississippi valley; and, as
no mica occurs in that part of the country, it is clear that the old excava-
tions, rudely made with stone tools, along the outcrops of large mica veins
in Forth Carolina, were the source of this material, which was evidently
prized by the prehistoric tribes and widely distributed among them.
It is a " far cry " from prehistoric mounds and ancient and long-
forgotten mica mines to the incandescent lighting of our present civiliza-
tion and the properties of rare chemical elements. But such are some
of the contrasts that present themselves in speaking of North Carolina
minerals. It is now some 18 years since the introduction of the
Welsbach incandescent burner, or rather mantle, that has so improved
our gas illumination. Instead of using the light produced by white hot
carbon particles, as in ordinary flame, a hood or mantle is employed,
which, when heated by the burning gas, glows with far greater intensity7.
This mantle consists of a loosely woven fabric impregnated with certain
compounds of rare elements. The first forms of it employed zirconia salts ;
and this fact led to active mining of the small, opaque, and previously
unimportant zircon crystals that are abundant at several points in North
Carolina. Since then it has been found that even greater brilliancy is
obtained by the use of nitrate of thorium. This latter is a rare metal,
found in very few minerals and in small amounts; but it is notably
present in monazite, a phosphate of this and other oxides of rare elements.
Monazite was formerly regarded as a very uncommon mineral, but it has
been found to occur quite abundantly in the sands of the stream-beds in
the South Mountain region, comprising several counties of North Carolina,
being derived from the disintegration of the country rock. Thus the
monazite industry has now become highly important,* and it is likely to
continue and increase; as the demand for thorium salts for incandescent
burners is very great. This latest stage of North Carolina mining — the
search for the " rare earths," so-called — has developed extensively within
a few years; though General Clingman was active in the earlier stages
of it, in promoting the zircon mining, and Mr. W. E. Hidden first brought
into use the monazite sands, and induced the Welsbach Company to
experiment with them in 1884. In 1901 the monazite output of North
Carolina was 748,000 pounds, valued at some $50,000. Only Brazil
surpasses, or even approaches, this production. In 1906 the output was
697,275 pounds, valued at $125,510. A total of 8,426,004 pounds valued
at $635,568, was mined in the 14 years 1893 to 1906, inclusive.
With these general historical outlines in mind, we may pass to a more
INTRODUCTION. XV
special account of North Carolina gems, that have been found, as above
noted, chiefly as incidents in the course of mining enterprises.
The diamonds of North Carolina, although small in size and few in
number, are undoubtedly authentic. The localities have been visited
and the discoveries verified by good mineralogists. Whether their occur-
rence will always be as sporadic as these, or whether others will be found,
time only can tell. Eubies, as fine in color as those of Burma, but gener-
ally small or containing imperfections, have lately been found in the
Cowee Valley, in Macon County; considerable mining for them has been
done, but the financial outcome is still somewhat problematical. Eme-
ralds, remarkable as crystals, but rarely transparent enough for gems,
were obtained in Alexander County, some years ago ; but a greater quan-
tity has been sold from the more recent Crabtree Mountain discovery, in
Mitchell County, where the emerald is translucent to transparent, in a
white granitic rock, and the whole is cut together as a matrix material —
the quartz and feldspar contrasting charmingly with the emerald green.
Aquamarines, which for beauty of colors have never been rivalled in any
country of the world, have been found in some profusion, and many gems
have been cut weighing from 1 to 30 carats, of the most beautiful sea-
blue color. Beryls, both sea-green and yellow, than which none richer
have ever been found, are also obtained in Mitchell County and elsewhere.
Mention should also be made of the peculiar "lithia emerald," or hid-
denite, found with the large emerald crystals above noted, at Stony Point,
Alexander County. This gem-stone was discovered in 1879 by J. Adlai D.
Stephenson, then sent by William E. Hidden to Dr. J. Lawrence Smith
of Louisville, who named it hiddenite. The garnets of the gold washings
are well known; but it remained for the Cowee Valley to produce a new
variety of garnet which has received a distinct name, rhodolite, and has
brought of late greater financial returns, probably, than any other North
Carolina gem. The amethysts from various localities equal those found
in any country of the globe; while smoky quartz, wonderful as crystals,
that have commanded the attention and study of some of the greatest
living crystallographers, has been obtained in Alexander and adjoining
counties. These specimens have frequently been fine enough to cut into
gems. But quartz in its choicest form, — rock crystal — has been found in
Ashe County in such magnificent masses that one of the finest art objects
shown at the Paris Exposition of 1900, was made from rock crystal ob-
tained in this county in 1888 by the author as was the cover of the
" Adams gold vase " presented to the same museum. These now form
parts of the Matthiessen gift and Edward D. Adams gift to the Metro-
politan Museum of Art, in New York, where they are two of the finest
objects in the entire museum.
XVI INTRODUCTION.
It is intended in this report to illustrate some of the principal North
Carolina gems, more remarkable usually as crystals than as precious stones
for jewelry, that grace the great collections before alluded to. All those
shown on the colored plates, and many of the others, are contained especi-
ally in the Morgan-Tiffany collections, presented by the munificence of
Mr. J. Pierpont Morgan to the American Museum of Natural History,
at New York ; these comprise the splendid collections formed by the author
for Tiffany & Company, of New York, of American gems and precious
stones shown at the Paris Exposition of 1889, and the still finer and more
extensive one displayed by them at the Paris Exposition of 1900 ; also the
Tiffany collection shown at the Cotton States Exposition at Atlanta, in
1894, and presented to the II. S. National Museum by Prof. L. T.
Chamberlin.
Many of the figures are loaned by the courtesy of the publishers of
" Gems and Precious Stones of North America," and will form part of
the new edition of that work, treating of the Morgan-Tiffany and Morgan-
Bement collections of minerals in the American Museum of Natural
History; this latter made up of the Spang collection and many from the
Hidden, Wilcox, and other collections. It was thought well to illustrate
for this report specimens in places which are readily accessible, and no
collection on this continent contains so many choice examples of North
Carolina gems as does this one.
Fuller discussions upon all these subjects, with geological, miner al-
ogical, chemical, or crystallographic details, may be found in the reports
issued by the North Carolina Geological Survey, which contains many
most valuable papers and monographs by such authorities as Kerr, Shep-
ard, Genth, Chatard, Hidden, Lewis, and Pratt, and in the Journal of the
Elisha Mitchell Scientific Society, published at Chapel Hill ; also in the
Annual Eeports of the Department of Mining Statistics of the United
States Geological Survey, prepared by the author under the directorship
first of Albert Williams, Jr., and then of Dr. David T. Day, who has done
everything to encourage and increase public interest in the development
of the precious stone and mineral resources of the United States. Many
papers have likewise appeared on the same topics in the American Journal
of Science. Among all these, much of the literature of the gem product
of the State may be found. It is the purpose of the present report to
present in a clear and concise manner such facts as may interest the
mineralogist, the collector, or even the tourist who wishes to acquaint
himself with these " crystallized flowers," as the celebrated Abbe Hauy
called them, whose enduring beauty remains unchanged by the variations
of climate found upon our globe.
INTRODUCTION. XV11
The mineral collections in the State Museum at Ealeigh include a
number of valuable and interesting collections of gems and gem minerals
prominent among which is that of Mr. J. A. D. Stephenson, for more than
30 years a resident of North Carolina and an enthusiastic explorer of
its natural resources.
Much credit is also due to the late James D. Yerrington, for many years
the agent of the Henry D. Morse Diamond-Cutting Company, who for
30 years carried on correspondence with North Carolina, doing much by
his kindly advice and care to encourage the people to send small gems,
which in many cases led to valuable results.
George Frederick Kunz.
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A
/Section of a .Sapphire crystal,
banded blue and yellow, Jenks Mine, Macon County,
North Carolina.
Asteriared sapphire,
Jackson County,
North Carolina.
#
Ruby,
J en ks M me , Macon County ,
North Carolina
D
First sapphire found ii
Corundum Hill, Macon Countv.
North Carolina.
Restored to matrix after beinq cut.
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Ruby,
- /alley,
Sapphire. (Brown.
Chatoyant,
McDowell ( bunty,
North Carolina.
G
Ruby,
vee Valley,
Macon CounK North .
Prepared under** directions of Gt»rj£FKiM
HISTORY OF THE GEMS FOUND IN
NORTH CAROLINA.
By GEORGE FREDERICK KlJNZ, Ph. D.
CHAPTER I.
HISTOKICAL SKETCH OF GEM MINING.
Gem mining in North Carolina had its origin; first, in the finding of
rolled crystals in the gold washings in several counties, some of them
of gem value, notably a few diamonds and occasionally a zircon or
epidote; then in the development of the mica mines, some of which
furnished some very beautiful beryls and others, garnets. Some of the
garnet crystals of wonderful color and brilliancy were frequently found
flattened between the plates of mica.
The first systematic mining for gems was undertaken by Mr. C. W.
Jenks, in 1871, when he opened the corundum mine, on Corundum Hill,
near Franklin, Macon County. This proved interesting scientifically, and
many choice gems were obtained ; and the name of the Jenks, or Culsagee,
mine became noted. The amount of gems found, however, did not warrant
permanent operations for gem corundum only, and after a few years the
mine was operated for corundum for abrasive purposes. Another promis-
ing mine, opened soon afterwards, was the Buck Creek, or Cullakeenee
mine, in Clay County ; but this has had much the same history. Next
came the mining for emeralds in Alexander County, at Stony Point, where
crystals had been found loose in the soil formed by the disintegration of
the country rock. As this region has never been subjected to glacial action,
as the northern part of the country has, anything found in the soil, apart
from stream-beds, has its origin presumably near the spot where it is
met with. The entire soil and upper portions of the rocks here consist of
what Professor Kerr called the " frost drift," i. e., the same as the under-
lying rock, but decayed and decomposed by frost and weathering in
general. Credit should be given here to the late Mr. J. Adlai D. Stephen-
son, of Statesville, who recognized these conditions and stimulated the
country people to search the surface of their fields for such crystals, of
2 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
which he gathered a great collection, in the hope of locating mines near
the points where anything of special interest was encountered. It was
thus that the emerald locality at Stony Point, which also yielded the
new and remarkable hiddenite gems, was traced. Later, the beryl mine
at Spruce Pine, Mitchell County (PI. II), was opened, and worked from
time to time, affording beautiful beryls. Then came the discovery of
true rubies near Franklin, Macon County, which has led to considerable
development and to the finding of some crystals which had gem value,
although never very great. Near this place occurs also the rhodolite — a
garnet between pyrope and almandite. This has been developed by two
companies with remarkable success, and apparently more gems in value
have been sold from this mine than from all other sources in North
Carolina combined. More recent still is the development of the emerald
matrix mine at Crabtree Mountain, near Bakersville, in Mitchell County.
Here the emerald occurs as small richly colored crystals, thickly strewn
through a white matrix of feldspar and quartz ; and the whole rock is cut
and polished together, as a green and white ornamental stone, which is
quite in favor. Amethyst of good quality, but not to any great extent, has
been developed in Lincoln and Macon counties.
Thus far, with the exception of rhodolite and beryl, the gem mines of
North Carolina have not proved remunerative enough to warrant a
continued development, either from absence of sufficiently rich material
or else from the use of methods that lacked cohesiveness to assure success.
A few notes may be given here as to some of the circumstances con-
nected with mining development and the men who were active in it.
General Clingman has been referred to already; another early and very
active worker was Mr. C. W. Jenks, who will be mentioned further in
relation to the first corundum development. One of the most energetic
explorers and discoverers of North Carolina minerals was Mr. J. A. D.
Stephenson, of Statesville. In 1888 he prepared for the author a sum-
mary of the results which he had attained in the years following the Civil
War; and from this little unpublished work the following passages are
taken, to show the spirit and the methods of his activity :
The Piedmont region lying between the Catawba and Yadkin rivers, is
remarkable for the number of minerals, both common and rare, that are
found in unusually fine crystals. Being a native of this section, and an
ardent admirer of all the phenomena and beauties of nature, these crystals
attracted my attention in early life, and the collection and study of
them .... convinced me that they were of more than usual interest; and
my early experience in the placer gold mines of North Carolina familiarized
me with the occurrence of such rare materials as monazite, xenotime, zircon,
columbite, etc., in this region; and knowing that these materials are found
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE II
HISTORICAL SKETCH OF GEM MINING. 6
associated with precious stones in other countries, impressed me with the
idea that by ... . systematic search, valuable gems would be found here,
but want of time and opportunity delayed the search until 1874.
I selected this section as the most convenient for my work. But the same
indications cross the State from northeast to southeast. In fact, to draw
a line .... from Paris, Maine, to Gainesville, Ga., it is surprising to me
how near it passes all the gem localities east of the Mississippi River.
My plan .... was to go among the people of the country, and endeavor
to interest them in collecting the different crystals found in their respective
sections; this I found an easy matter, especially with the children, as they
took hold of the idea readily and many of them soon became familiar with the
work, and not only did good service in developing the mineral resources of
the State, but many of them have acquired a good knowledge of mineralogy
and general natural history.
Mr. Stephenson's discoveries form almost the only exception to the
general statement made at the outset, that the discoveries of gems and
gem-minerals in North Carolina arose incidentally in the search or min-
ing for gold, corundum, mica, or the rare earths. Mr. Stephenson had
described how he set about the search for gems directly, in the assurance
that they must exist and could be traced by sufficient endeavor. In almost
all other cases, the discoveries have been made accidentally in the course
of other mining operations.
A recent letter to the writer from Mr. D. A. Bowman, of Bakersville,
for example, states the usual facts as follows :
As to the discovery of beryl, and other gems, this was invariably by mica
mining, for outside of a mica vein, I have never known a beryl to be found.
In working for black mica, the beautiful beryl at Buchanan Mine was found.
It was the same at Grassy Creek, where Wiseman and McKinney found the
deep green aquamarines, and then sold to the " American Gem Company."
I identified the beryl found by Wiseman and McKinney and shipped it to
Tiffany & Company.
It was Mr. Rorison and myself that first discovered the emerald matrix
at Brush Creek Mountain, in 1894 or 1895 For 35 years I have
worked hard to bring to light the various minerals and gems, and through
your kind assistance I feel I have not worked in vain, and have been of
some little service to my country.
In the same letter, Mr. Bowman gives an interesting account of the
first opening of a mica mine, shortly before the war. In 1858, General
Clingman, while traveling in the western part of the State, stopped over
night with a Mr. Silver, near Bakersville, and was interested to find
a window filled with 8 by 10 inch panes cut from sheets of mica, or as it
was generally called, isinglass. The very next day, having been shown
the spot where this novel material was found, General Clingman hired
workmen and began sinking a shaft. Mica was taken out in magnificent
4 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
blocks; but General Clingman was more interested in a brilliant pyrites
in the adjacent feldspar, under the impression that it was a silver ore.
After the war had closed, in 1869, the old mine, long known in the
vicinity as the " Sink-hole," was brought to the notice of a stove company
in Knoxville, Tenn., who began to operate it for the mica, with great
success. Another mica mine in the same section, the " Cloudland," was
discovered accidentally at about the same time, and proved to be also
valuable. Quite a local excitement sprang up, and much prospecting
was done for mica, with the result that several important mines were
discovered. One of these, the " Clarissa/' has yielded as much as half a
million of dollars, by Mr. Bowman's estimate. It has been worked down
to 400 feet, and is now stopped by water; but only awaits improved
machinery and a rise in the price of mica, to be reopened with profit.
With all that has been discovered, however, and all that has been done,
in North Carolina gems, there are evidently much greater possibilities
in the future. One suggestion of a practical kind may be made in
closing this introductory chapter.
A wonderful development has gone on in North Carolina in the direc-
tion of the great hotels at Asheville and Toxaway and the mountain re-
sorts at Linville, Cranberry and elsewhere, and a large tourist class visit
this region every year. If some of the native prospectors should use their
spare moments as do those in Eussia, they would gather, mine and
then cut the rock crystals, smoky quartz, and other stones of the region,
shaping them into ornamental forms, as the inhabitants of the Ural
Mountains have done since the eighteenth century, when Catherine the
Second sent two Italian lapidaries to educate them in the art. This might
well prove a source of interest and profit to the people of the State.
CHAPTER II.
DIAMOND
The mining of gems in this State had its origin in the finding of rolled
crystals of gem value in the gold washings. In these regions have been
found crystals of diamond, either loose in the soil, or taken from the
washings of auriferous gravel.1 The portion of the State which has
yielded these valuable substances is that known as the Piedmont region —
a broad belt of country, as its name indicates, at the foot of the mountains,
along the eastern base of the Blue Eidge. The rocks here are meta-
morphic and crystalline, with some Cambrian beds a little farther west.
There runs throughout much of this region a belt or belts of itacolumite,
the so-called " flexible sandstone," which is also found in Brazil and in
the Ural Mountains, and has frequently been supposed to be the matrix
of diamond crystals. The presence of this peculiar rock and the occasional
discovery of diamonds in adjacent districts have led to the idea that the
itacolumite belt of North Carolina might prove to be a valuable diamanti-
f erous region ; but as yet no diamonds have actually been discovered there,
and but few have been found in the loose debris of the crystalline beds.
The late Prof. Frederick A. Genth, of the University of Pennsylvania,
described2 the occurrence of the 2 crystalline varieties of carbon in that
State, — the graphite in beds interstratified with schist or gneiss; the
diamond in the debris of such rocks, associated with gold, zircon, garnet,
monazite, and other minerals, and after speaking of this occurrence in
connection with rocks of identical age, as a very interesting circumstance,
he says : " The diamond has not been observed in North Carolina in any
more recent strata, and in the itacolumite regions no diamonds have
ever been found, as in Brazil ; from which it appears that the itacolumite
of Brazil is either simply a quartzose mica slate of similar age with the
North Carolina gneissoid rocks, or, if it be contemporary with the
North Carolina itacolumite, the diamonds were not produced in the same,
but came from the older rocks and were redeposited with the sands
resulting from the reduction to powder of these, and are now found
imbedded in the same, their hardness having prevented their destruction.
Seven or 8 diamonds have thus been found. They occur distributed
1 Gems and Gem Mining in the South, hy Joseph Hyde Pratt ; The Southland, Vol. I,
No. 2, p. 4, 1901.
2 Mineral Resources of North Carolina, p. 28, Philadelphia, 1871.
0 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
over a wide area of surface in the counties of Burke, Kutherf ord, Lincoln.
Mecklenburg, and Franklin, and I have no doubt if a regular search were
to be made for them, they would be more frequently found." To the
counties named by Professor Genth, must now be added McDowell, and
these all form, with the exception of Franklin, a group lying together in
the line of the general drainage of the country, southeast of the Blue
Eidge. Franklin County is far to the northeast of the others; and any
diamonds occurring there must be derived from the disintegration of
another belt of crystalline rocks, that traverses the eastern portion of the
State, near Weldon, in Halifax County, or else have been transported for
a long distance by streams.
Up to the present time there are about ten authentic occurrences of
diamonds in North Carolina, besides several reported discoveries that are
not entirely reliable.3 One such instance was that of a quartz crystal
found near Danbury, which was examined, and pronounced a (genuine)
diamond, by the local jewelers, who valued it erroneously at some
thousands of dollars.
The first specimen in order of time, was found in 1843, by Dr. F. M.
Stephenson, at the ford of Brindletown Creek, in Burke County. It
was an octahedral crystal, and was valued at $100 ; but no particulars of
it are on record. Another was found in the same neighborhood by Prof.
George W. Featherstonhaugh, but there seems to be no account of its
characters preserved. In 1845, a diamond of 1J carats, a distorted octa-
hedron with curved faces, clear and flawless, though tinged with yellow,
was found in the gold washings of J. D. Twitty's mine, in Rutherford
County. It became the property of the late General T. L. Clingman, of
Asheville, who for many years took great interest and did great service
in developing the mineral resources of North Carolina. This stone was
described by Prof. Charles U. Shepard,4 who announced the existence
of itacolumite in the gold-bearing region of North Carolina, at the
meeting of the American Association of Geologists and Naturalists in
1845, and under the impression that the itacolumite is their matrix, had
predicted the further discovery of diamonds in that region, as in Brazil.
For this reason diamonds, when found, were naturally submitted to him.
C. Leventhorpe, of Patterson, Caldwell County, N. C, reports a small
and poor specimen found in a placer mine on his property in Eutherford
County, and states that he presented it to Prof. Shepard, who retained it
in his cabinet. The next important diamond was found in gold-washings
3 Sketch of N. C, issued by the Dept. of Agriculture. Raleigh, to accompany the State
Exhibit at the Charleston Exposition, 1902. Diamond, pp. 40, 41.
4 Am. Jour. Sci., Vol. II, p. 253, Sept., 1846.
DIAMOND. 7
in 1852, by Dr. C. L. Hunter, near Cottage Home, Lincoln County. It
is described as an elongated octahedron of a delicate greenish tint, trans-
parent, and about half a carat in weight. Another, said to be a very
handsome white crystal of 1 carat, was obtained in the same year, at
Todd's Branch, Mecklenburg County; it became the property of the late
Dr. Andrews, of Charlotte, N. C, who also informed Prof. G-enth that a
beautiful black stone " as large as a chinquapin " was afterwards found
by some gold-washers in the same locality. This specimen, unfortunately,
was crushed with a hammer, sharing the fate of several American
diamonds when submitted to the mistaken test which confounds hardness
with strength. The fragments of the black diamond scratched corundum
with ease, thereby proving its genuineness.5 Soon after this two dia-
monds, one a beautiful octahedron, were reported by Prof. F. A. Genth,
as obtained at the Portis mine, in Franklin County. This locality is far
removed from the others in North Carolina, — a point which is referred to
presently.
Two discoveries are recorded in McDowell County, one of two or three
small crystals found at the headwaters of Muddy Creek, and the other
a fine stone picked up at a spring near Dysartville, in 1886.6 This was a
distorted and twinned hexoctahedron, of 4-J carats, transparent, with a
grayish-green tint. The little son of Mr. Grayson Christie, going for
water to a spring on the farm of Alfred Bright, observed this peculiar
shining pebble, and brought it home. After some local interest had
developed, its nature was suspected, and it was sent to New York and
there at once identified. A model of it was exhibited at the Paris Ex-
position of 1889, and is now in the Tiffany-Morgan collection of the
American Museum of Natural History. The present writer subsequently
visited the spot, and fully authenticated all the facts of the discovery.
The sediment in the bed of the spring was taken out and examined, and
also the small hollows on the adjacent hillside. None of the ordinary
associations of the diamond were observed, and hence it is probable thai
the crystal was washed down with decomposing rock-soil from higher
ground, perhaps during some freshet ; or possibly it may have been carried
to the spring by miners, and left unobserved or unrecognized among the
" wash-up " of the gold-bearing sand from some neighboring placer.
There are gold mines in McDowell County, worked chiefly by hydraulic
sluicing, but as a rule the stones that remain in the sluices are carefully
examined, as the miners know that gems are sometimes thus found.
The value of the Dysartville diamond as a jewel will hardly represent the
3 Handbook of North Carolina, Raleigh, 1886, pp. 197, 198.
6 Am. Jour. Sci., Vol. XXXIV, Dec, 1887, p. 490.
8 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
interest that attaches to it as a local specimen of large size and fine
appearance. (See Plate III.)
Another diamond is reported to have been found 9 years before, in 18? 7,
by a small boy, in the same region as the last. It weighed 2f carats,
and is described as white and lustrous, but somewhat flawed, and of
irregular flattened form, resembling a bean, with the crystal faces
obscure. The finder sold it in Marion for a mere nominal sum. Mr.
B. B. Price, of Marion, put it for disposal into the hands of Mr. James
M. Gere, of Spruce Pine, an extensive buyer and miner of North Carolina
mica. He took it to Syracuse, N. Y., and sold it there to Messrs. C. M.
Ball & Co., jewelers, for the sum of $18. It was finally sent to New
York, where it was cut into a small gem and its identity lost.7
Still another crystal is in the State Museum at Ealeigh. The partic-
ulars of its discovery are not known; but it was purchased by the State
with the collection of the late Dr. J. A. D. Stephenson, of Statesville,
N". C, who had possessed it for some years, and reported that he had
bought it, with other minerals, from a countryman in Burke County.
It has an oblong spheroidal form, the faces being curved and rounded;
and it weighs 5/16 of a carat. These particulars are given in a recent
letter from Mr. T. K. Brunner, Secretary of the State Department of
Agriculture at Ealeigh.
The latest well established discovery was in 1893, in Cleveland County,
near King's Mountain. It was a polished octahedron, weighing J carat,
of a bright light canary yellow.
It will be noticed that most of these localities are situated in the
same section of the State, — in the mountainous district, lying just
north from the northernmost extension of the border of South Carolina.
Here the counties of Burke, Eutherford, McDowell, and Cleveland lie
closely adjacent, and Mecklenburg only a short distance eastward.
The foregoing list includes all the authentic diamonds thus far
discovered in North Carolina. A number of small stones, exhibited as
diamonds, have been found at Brackettstown. They are similar to
supposed diamonds found by J. C. Mills at his mine at Brindletown, but
these were transparent zircon or smoky-colored quartz, the former of
which has a lustre readily mistaken by an inexperienced person for that
of a diamond. A number of pieces of rough diamond, exhibited as
from the same section, have been decided to be of South African, not
Carolinian origin. It is to be hoped that the few legitimate discoveries
7 Addendum to the " Minerals and Mineral Localities of North Carolina," by William
Earl Hidden, p. 2, 1889 ; Reprinted from Jour, of the Elisha Mitchell Scientific Society,
6th year, part II. Raleigh, 1890.
Plate No HI
IV G
Diamond,
Dysortvi
McDowell County.
North Carolina.
Alexander County
Ncrih Carolina.
Aquamarine, ( Blue
Spruce Pine,
Mitchell (buniy,
North Carolina.
Beryl Cats Eye
Spruce Pine,
Mitchell County,
North Carolina.
Aquamarine,
(.Sea Green. )
Spruce Pine,
Mitchell County,
North Carolina.
F
Hiddenite.
Stony Point,
AlexanderCounr
North Carolina.
Emerald Matrix
' !rabtroc Mounl
Mitchell Co>...
North Carolina.
1 iili byUshei I'm no A;
■ I
DIAMOND. 'J
actually made in this locality will not lead to deceptions, which would
greatly retard any natural development of interest. It is quite possible
that diamonds may be found widely distributed throughout the auriferous
belt of the Carolinas and northern Georgia; and that, in the often rude
and hurried methods of gold-washing employed, they may have been
overlooked in the past, and now lie buried in the piles of sand that
stretch for miles along the water-courses.8 It is stated that 3 diamond
crystals were obtained many years ago on Koko Creek, at the headwaters
of the Tellico Eiver, in East Tennessee, on the " Bench lands " of the
Smoky or Unaka Mountains. If this statement be correct, it probably
points to a western extension of the diamond belt of North Carolina, or
to the transportation of the stones thence by streams.9
Franklin 'County is far removed, both geographically and geologically,
from all the other points above noted; and indeed in both aspects, a
possible relation is suggested rather with the celebrated Manchester, Vir-
ginia, diamond. In both these cases, if the diamonds came from the
Blue Eidge, they must have been carried a long distance by streams. There
is, however, a possible nearer source, in the belt of " Atlantic " or " Tide-
water " gneiss, which runs down from New York to and through the
Carolinas, forms the rapids in the James at Richmond, and goes on
directly toward Franklin County, North Carolina. This is merely a
suggestion, however, caused by the geographical isolation of these two
occurrences; nowhere else along this gneissic belt have diamonds ever
been found.
8 Gems and Precious Stones of North America, by Geo. F. Kunz, New York, 1890, p.
21. 8vo, 363 pp.
M. o... p. 35.
CHAPTER III.
COKUKDTTM GEMS.1
While diamonds and gold are found in the Piedmont country east of
the mountains, North Carolina's chief corundum rocks are in Madison,
Buncombe, Haywood, Jackson, Macon, and Clay counties, where numer-
ous occurrences are known. A second and a third line of localities are
recognized, but they are of slight importance. There are occurrences of
corundum, however, east of the mountains, in the counties of Gaston,
Lincoln, Burke, Iredell, Guilford, and Forsyth. The late Prof. John A.
Humphreys called attention to some of these in 18 — , in his paper No. 12
of " Natural History Notes on Western North Carolina," and suggested
their possible importance in comparison with those farther west. Some
of the earliest specimens, also, were collected in Gaston and Lincoln
counties, as will be noted further on. But the main corundum region is
beyond the Blue Eidge, where it forms a belt or zone of large extent,
stretching along the whole course of the Southern Appalachians. The
principal corundum gems are the ruby, sapphire, and oriental emerald.
According to Dr. Thomas M. Chatard,2 of the United States Geological
Survey, the corundum region extends from the Virginia line through the
western part of South Carolina, and across Georgia as far as Dudleyville,
Ala. Its greatest width is estimated to be about 100 miles. This
belt has sometimes been called the chrysolite or chromiferous series,
owing to the presene of chrysolite containing chromite, from the former
of which corundum was believed, by certain authorities, to have been
derived by alteration.3 In this decomposed and altered chrysolite (dunite)
throughout the Southern States, corundum is found in place; and the
earlier writers on the subject, including such eminent authorities as Dr.
J. Lawrence Smith and Prof. Charles U. Shepard,4 believed it to be con-
fined to the serpentinous rocks of this belt, which represent largely an al-
1 For more detailed descriptions of corundum occurrences in North Carolina, refer-
ence is made to Reports, N. C. Geol. Survey, Vol. I, 1905, on Corundum and the Basic
Magnesian Rocks of N. C, by Joseph Hyde Pratt and Joseph Volney Lewis ; Corundum
and the Basic Magnesian Rocks of N. C, by J. Volney Lewis, Bull. No. 11, 1895 ; and also
Gems and Gem Mining in the South, by Joseph Hyde Pratt ; The Southland, Vol. I,
Nos. 3 and 4, 1901.
2 Mineral Resources of the United States, p. 714, 1883-1884.
3 See Corundum : Its Alterations and Associated Minerals, by Frederick A. Genth,
in Contributions from the Laboratory of the University of Pennsylvania, No. I, Phila-
delphia, 1873.
4 Corundum and its Gems : A Lecture before the Society of Arts, Boston, 1876.
CORUNDUM GEMS. 11
teration product of chrysolite. Such was the general view during the
years following the Civil War, when the mineral resources of North Caro-
lina were beginning to be actively developed.
More recently, it has come to be seen that this is only one phase of
corundum occurrence, although much the most conspicuous. The investi-
gation of the Geological Survey, conducted by Dr. Joseph H. Pratt,0
and Prof. Joseph Volney Lewis,6 have traced several distinct associations
in which corundum appears. Three of these are clearly developed in
North Carolina: — (1) In the crystalline schists, as long prismatic crys-
tals, usually opaque, grey, pink, or blue; (2) in the decomposed chrysolite
or peridotite rocks, called dunites, that intersect the schists, as igneous
intrusions; the crystals often large and variously colored, but very rarely
of gem quality; (3) in more or less decomposed basic rocks, with garnets,
in the Cowee Valley in Macon County, where the crystals are small, in
six-sided tables or to some extent rhombohedral, sometimes transparent
and rich red. These last are the " Cowee rubies." The second group
corresponds to the chrysolite or serpentine occurrence noted by the
earlier writers ; the first has been but recently distinguished with clearness
from the second. It appears now, through further researches of Dr. Pratt
that under this first head are again included two very different modes of
geological occurrence, — one in a hornblende gneiss arising from the
alteration of an igneous rock and its foliation by pressure, and the other
in a true gneiss varying to a quartz schist, which has resulted from the
metamorphism of sedimentary strata. These latter gneisses occur sepa-
rately, extending along the crest of the Blue Kidge, at an elevation of
3000 to 4000 feet, from Eabun County, Georgia, to Clay Count}', N. C.
The corundum appears in irregular bands in the gneiss, evidently
belonging to it, and not in veins or dikes. Dr. Pratt concludes that these
were originally aluminous shales, and that in the long process of meta-
morphism, the alumina may have first separated as bauxite (hydra ted
oxide), and subsequently formed corundum bands parallel to the planes
of lamination.
In all the other cases, the corundum is a product of true igneous action,
having either crystallized out from a molten rock directly, or formed at
the contact zones of such rock with others which it penetrated, by mutual
chemical actions under the influence of great heat. The former is a
frequent manner in which corundum exists. The extensive deposits lately
made known in Ontario, are in a nepheline-syenite, plainly igneous in
5 Amer. Jour. Sci., Vol. VI, Pt. 4, p. 59, 1898 ; Vol. X, pp. 295-298, 1900.
0 N. C. Geol. Survey, Bull. 11, 1896 and Vol. I, 1905.
12 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
origin, and the gem corundums of Montana are derived from intrusive
dikes. The occurrence in crystalline limestone, in northern New Jersey,
like that in Burma, is probably of the other type, a result of contact
metamorphism, although Messrs. Brown and Judd have advanced a
theory for the Burman mines, that attributes even these to an original
igneous source.
The whole question of the geology of corundum, — its origin, mode of
formation, etc., has been obscure and uncertain for a long time. Many
theories have been advanced, only to be modified by subsequent dis-
coveries. Within a few years past, however, important progress has been
made; and though much remains to be ascertained, a number of points
have gradually been established.
Among these is the fact that corundum, long regarded as a somewhat
rare mineral, is really of more frequent occurrence than was formerly
supposed ; and also that it has been formed under various conditions and
in several distinct ways. As already stated above, it is now known to
have been produced (1) by crystallizing directly out of igneous rocks;
and (2) by various forms of alteration and metamorphism, in both
igneous and sedimentary rocks. The first head is further divided into
occurrences in basic and in acidic rocks, and again into cases when the
alumina was present in excess in the igneous rock itself, as an original
constituent (autogenic), and those when it was introduced in pieces of an
aluminous shale traversed by the igneous rock and taken up by it in its
ascent (allothigenic). All these eases of occurrence have now been fairly
identified in the corundum localities in the United States.
The earlier writers generally held that pure alumina (corundum )was
a secondary or derivative mineral, formed by the alteration of other species
in which it had previously existed in combination, as a silicate. Its
close association with the altered peridotite or chrysolite (dunite) belt
of the South Atlantic States, has already been referred to, and the belief
of some geologists that the corundum was derived from the chrysolite, by
various processes of alteration. The late eminent Dr. F. A. Genth, while
not committing himself to any positive statement as to the origin of the
corundum, developed a remarkable body of facts as to the alteration of
corundum itself into various other and associated minerals.' There is not
space here to go into any full outline of the course of observation and
opinion. This has been very well done by Dr. J. H. Pratt, of the North
Carolina Geological Survey, in his recent paper " On the Origin of the
Corundum associated with the Peridotites in North Carolina." s In this
7 The Alterations of Corundum; Proc. Am. Phil. Soc, XIII, pp. 361-406, 1873.
8 Am. Jour. Sci., IV, Vol. VI, No. 31, July, 1898, pp. 49-65.
CORUNDUM GEMS. 13
article he shows how the igneous origin of these peridotites or dunites has
come to be gradually established, and the separation of the corundum from
them as an original ingredient. In a subsequent and more extended paper
on " The Occurrence and Distribution of the Corundum in the United
States," 9 Dr. Pratt describes all the known localities, and the special
features of each.
A full and excellent account of the distribution, the geology, and the
history and literature of corundum, with special reference to Georgia, has
also been given by Prof. Francis P. King, assistant geologist of that
State, in his " Preliminary Eeport on Corundum Deposits in Georgia." 10
The earliest discovery of corundum in the United States was reported in
1819, by Mr. John Dickson, in an article on the mineralogy and geology
of the two Carolinas, published in " Silliman's Journal." u The crystals
which he obtained came from Laurens District, S. C, a locality which has
since yielded a considerable amount of both corundum and zircon.
Of corundum in North Carolina, the first recorded account is the
statement by Prof. C. D. Smith, who was the assistant State Geologist
under Professor Emmons, that it was found in 1846, but he does not
say where or by whom. Dr. F. A. Genth reports that a large mass of
corundum was obtained in 1847, in Madison (then a part of Buncombe)
County, on the French Broad Eiver, 3 miles below Marshall.
This was a dark blue piece, associated with chlorite and margarite.
In 1849 or 1850, Prof. Charles U. Shepard received from Gen. Thomas L.
Clingman several pounds of a coarse blue sapphire broken from a large
crystal " picked up at the base of a mountain on the French Broad
Eiver in Madison County, N. C." This is probably the same discovery as
that previously noted.
Whether the Indians knew anything of corundum is uncertain. It is
too hard for them to have worked it in any way, and it has not been
recognized among any of the minerals occasionally found in graves or
mounds. As Professor King of Georgia says, it is not unlikely that some
of the pink or blue fragments of crystalline corundum found in the
gravels of the Southern States may have been noticed and prized as
ornaments; but the aborigines certainly made very little use of it
otherwise. A curious fact is noted by Professor King, however, in refer-
ence to the corundum mine at Track Eock, in Union County, Georgia, —
that near the locality is a rock covered with curious carvings, many of
them resembling animals tracks, whence the place derives its name.
9 U. S. Geol. Survey Bull., No. 180, 93 pp., 1901, and Bull. 269, 175 pp., 1906.
10 Geol. Survey of Georgia, Bull. No. 2, 133 pp., 1894.
"Am. Jour. Sci., I, Vol. Ill, p. 4.
14 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
Possibly the Indians may have employed fragments of corundum in
executing these designs on the rock (?).
This first recognition, far to the west, was soon followed by some on
the eastern side of the Blue Eidge. In 1852, Prof. E. T. Brumby, of the
College of South Carolina, collected specimens of corundum at Clubb
(now Chubb) Mountain, in Gaston County, and placed them in the
cabinet of the College, where they still remain, with Prof&ssor Brumby's
dated labels. They are rough crystals and crystalline masses, of dark
blue color, covered with the micaceous alteration-products so frequently
present; but they have high interest in being perhaps the first North
Carolina specimens to be determined, labeled, and placed in a public
collection. About the same time Dr. C. L. Hunter discovered corundum
in Gaston County, perhaps at the same locality, and Professor Emmons
referred to it in his report on the midland counties of Xorth Carolina in
1853.12 The Civil War began soon after, putting a stop to further research,
and it was not until its close that investigations were resumed.
Eev. C. D. Smith, of Franklin, N". C, who in his former position on
the State Geological Survey, had become very familiar with the minerals
of the State, now discovered most of the important localities in North
Carolina. In 1865 a specimen was brought to him from a point west of
the Blue Eidge, which he recognized as corundum ; he visited the locality,
collected specimens, and announced the occurrence. This was the origin
of the mining industry now so valuable. These discoveries led to further
exploration, and many localities were found in the same region, which
have since been more or less developed.
In 1870, Mr. Smith sketched the corundum belt of North Carolina,
as running in a southwesterly course across Macon County, where it
strikes the Georgia State line, its general direction coinciding with the
trend of the Blue Eidge, until it reaches the head of the Tennessee Eiver,
when it suddenly ceases on encountering the Nantahala Mountain (a
spur of the Blue Eidge here running due north), to reappear 10 miles to
the northwest on Buck Creek, whence it pursues its original course of
northeast and southwest across the Chunkygal mountains, where it again
enters the Blue Eidge. Later investigation has revealed a more extended
belt.
Two of the localities in this region have been much the more promi-
nent,— those at Corundum Hill and Buck Creek.
With the opening of the Culsagee (Cullasagee, or Cullasaja) mine, on
Corundum Hill, near Franklin, Macon County, by Mr. C. W. Jenks, in
12Amer. Jour. Sci., II, Vol. XV, p. 373, May, 1853.
CORUNDUM GEMS. 15
1871, the first systematic attempt to mine gems within the State was
begun. From a scientific point of view the operations were most interest-
ing, but the number of gems found did not warrant permanent operations,
for gems only, and after a few years mining for this mineral was for
abrasive purposes.
This mine, which includes several openings, is situated on the Culsagee
or Sugartown Fork of the Little Tennessee Eiver, 8 or 9 miles above
(southeast of) the town of Franklin, the county seat, at an elevation
of about 2500 feet above the sea. The Corundum Hill is essentially an
outcrop of peridotite (dunite), some 10 acres in area, and rising to a
height of between 300 and 400 feet. Most of the openings are along the
contact of the dunite with the gneiss or schist through which it rises,
and follow " contact veins " of corundum. It has often been called the
Jenks mine, also the Culsagee and the Corundum Hill, names derived
from the locality and from the name of its first operator, Charles W.
Jenks, of Boston, Mass. It was subsequently worked by the Hampden
Emery Company, of Chester, Mass., under the direction of Dr. S. F.
Lucas, and became known as the Lucas mine. It is now owned by the
International Corundum & Emery Co., of New York, which also controls
several other less important mines in the same neighborhood.
The other prominent locality was the Buck Creek or Cullakenee (also
spelled Cullakeenee and Cullakenish) mine, in Clay County, 20 miles
southwest of Franklin. It was opened soon afterwards, and has had a
similar history. The outcrop is much more extensive, but less work has
been done there.
These mines, especially the first, have been described in various scientific
papers and reports. One of the earliest published accounts was given by
Prof. C. U. Shepard 13 in 1872 ; another was by Mr. Jenks himself, 2
years later, in a paper read before the Geological Society of London. In
1876, Prof. Eossiter W. Eaymond read an excellent paper before the
American Institute of Mining Engineers"; in 1883, Dr. Thomas M.
Chatard, of the XL S. Geological Survey described it again.18
Besides these valuable articles, there are the no less excellent references
in various reports of the State Survey, by Prof. W. C. Kerr, and in
articles by Dr. F. A. Genth, who was associated with him in portions
of the survey work, and by Dr. J. Lawrence Smith.
Professor Shepard described the dunite rock very well, and recognized
it distinctly as an altered form of chrysolite, referring it to the species
13 Am. Jour. Sci., II. Vol. IV, Aug.-Sept., 1872.
14 Trans. Am. Inst. Min. Eng., Chattanooga meeting, May, 1876.
15 Mineral Resources of the U. S., 1883-1884, p. 714.
3
16 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
known as villarsite. Dr. Eaymond fully perceived its character as an
igneous intrusion, differing from some other writers on this point, since
clearly established. Dr. Chatard describes the Culsagee outcrop as con-
sisting of chrysolite (dunite) mingled with hornblende. The corundum
is enclosed among various hydromicaceous minerals, commonly grouped
under the term chlorite, between the gneiss and the dunite, from the
alteration of which they have evidently been formed. It occurs chiefly
in crystalline masses, often of considerable size, and sometimes suitable
for gems (PI. IV, A). At other parts of the mine it is found in small
crystals and grains mingled with scales of chlorite, forming what is called
the " sand vein." This is so loose and incoherent that it is worked by the
hydraulic process; and the small size of such corundum is the saving of
much labor in the next process of pulverizing. At Buck Creek the
chrysolite rocks cover an area of over 300 acres, and from that point
southward the hornblende rocks assume greater proportions, being asso-
ciated with albite instead of the ordinary feldspar and forming an
albitic cyanite rock. There is also found here the beautiful green
smaragdite, called by Professor Shepard chrome-arfvedsonite, which,
with red or pink corundum, forms a beautiful and peculiar rock curiously
resembling the eclogite or omphacite rock of Hof, in Bavaria, as Professor
Shepard had noted in his early article in 1872.
Both these localities have also been recently described, with maps, in
the admirable report of Dr. J. H. Pratt and Prof. J. V. Lewis, elsewhere
referred to.16
The resemblance in the occurrence of the North Carolina corundum to
that of Mramorsk in the Ural Mountains, as described by Prof. Gustav
Rose of the University of Berlin, has been shown by Professor Genth.17
There the associated species are serpentine and chlorite schist, sometime?
with emery, diaspore, and zoisite, very similar to the chrome serpentine
corundum belt of the Southern States. The emery deposits of Asia Minor
and the Grecian Archipelago, according to Dr. J. Lawrence Smith,18 yield
that substance in marble or limestone, overlying gneissic rocks; while
with it are associated many of the same hydromicaceous and chloritic
species that accompany both the New England emery and the southern
corundum.
With more particular reference now to the actual gems yielded at these
various localities, we may note that they occur in two distinct forms:
first, as crystals, of which the usual forms for sapphire are doubly termi-
16 Corundum and the Peridotites of North Carolina, N. C. Geol. Surv., Vol. I, 1905.
17 Contributions to the Laboratory of Penn. Univ., No. 1, 1873.
M Am. Jour. Sci., II, Vol. X, p. 355, Nov., 1850 ; and Vol. XII, p. 53, Jan., 1851.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE IV
A. TRANSPARENT BLUE AND GREEN SAPPHIRE, NATURAL SIZE, MACON COUNTY, N. C.
15. CORUNDUM, SHOWING ALTERATION, NATURAL SIZE, HAYWOOD COUNTY, N. C.
CORUNDUM GEMS. 17
nated hexagonal pyramids, often barrel-shaped by the occurrence of a
number of pyramidal planes of successively greater angle; and second,
as nodules of purer and clearer material, in the midst of larger masses of
ordinary cleavable corundum. These, when broken or falling out, are
sometimes taken for rolled pebbles, which they resemble. This latter,
and quite peculiar mode of occurrence is treated of somewhat in the able
paper on this mine, read by Prof. Eossiter W. Eaymond, in May, 1876,
before the American Institute of Mining Engineers, and published in
their Transactions.
In regard to the relations of different kinds of corundum, Dr. Pratt
says : — " The corundum gem or sapphire localities are usually distinct
from corundum localities, although very handsome gems have been found
where corundum was mined for abrasive purposes, notably at the
Corundum Hill mine." 19
In 1874, Mr. C. W. Jenks read a paper on the occurrence of sapphires
and rubies in situ in corundum, at the Culsagee mine, before the Geolog-
ical Society of London; in this brief but important article he described
the location and mineralogical character of the mine, and the fact of the
presence of portions in the corundum of true gem quality. The paper
attracted much interest, and Prof. David Forbes said that great credit
was due to Mr. Jenks, and that he had " discovered the actual home " of
the true ruby and sapphire, which had never before been really traced
to their sources (see PL I).
Some years later, a London periodical made the statement that any one
who found the sapphire or the ruby in its original matrix would be
called the " King of Rubies," and that his fortune would be assurred.
But such is not always the result to those who deserve it. Mr. Jenks was
undoubtedly the original finder of the true corundum or sapphire gems-
in place, and he obtained from this locality nearly all the fine crystals of
the best American collections. One of the most interesting of these is a
piece of blue corundum with a white band running across it and a place
in the center where a nodule had dropped out. This piece was cut and
put back in its place, and the white band can be seen running across both
gem and rock. (See colored PL 1.) Nearly all the fine gems from
Franklin, N. C, were brought to light by Mr. Jenks' mining; but
although found in their original matrix, they were of such rare occur-
rence that it was found unprofitable to mine for them alone. The work
was subsequently suspended for some time in consequence of the financial
crisis of 1873, but resumed by the Hampden Emery Company.
18 Corundum in the United States, J. H. Pratt, 1901, p. 10 (Bull. No. 180, U. S. Geol.
Survey).
18 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
The largest crystal ever found, which is 5 times larger than any other
known, is one early discovered by Mr. Jenks and described by Professor
Shepard.20 It is now in the cabinet at Amherst College: but much
injured by the disastrous fire of 1882, which destroyed so many fine
specimens of the Shepard collection. It weighed 312 pounds, and meas-
ured 22 inches in length, 18 inches in breadth, and 12 inches in thickness.
In form it was a steep and somewhat irregular six-sided pyramid, termi-
nated above by a rather uneven basal plane. Its general color is grayish
blue.
In addition to these and other notable crystals, many public collections,
besides the American Museum of Natural History (which possesses
much the finest series), contain numerous cut gems from this mine.
A blue stone of over 1-carat weight is in the United States Xational
Museum at Washington, and a series of fine red and blue crystals have
been deposited there by S. F. Lucas. In the collection made by the late
Prof. Joseph Leidy, of Philadelphia, and now also in the Xational
Museum, are several gems from the same mine, including a wine-yellow
sapphire of 3£ carats (660 milligrams) ; a violet-blue stone of a little
over 1 carat (215 milligrams) ; and three dark-blue ones weighing
respectively about 1^ (320 milligrams) ; 1J (250 milligrams) ; and J
(145 milligrams) carats each.
In Dr. Spencer's notes on American gems in the British Museum of
Xatural History, London, is noted a specimen of corundum from Corun-
dum Hill, Macon County, X. C, which consists of a rough hexagonal
prism, 26 cm. long and 18 cm. across, of a reddish color.
In a recent report of Prof. J. H. Pratt, State Geologist, he thus refers
to gems from this locality :
At the Corundum Hill Mines, Cullasagee, N. C, various shades of gem
ruby corundum have been found. Two of the best rubies of good color that
have ever been found at this mine are in the collection of Clarence S.
Bement, of Philadelphia; there are also a number of fine ones in the United
States National Museum at Washington. Many of the smaller crystals of
various shades of pink to red are transparent near the outer surface and
near their extremities, and from these small gems can be cut, but few that
are worth $100 have been obtained from them.
Probably the finest emerald green colored sapphire in the world came
from the Culsagee mine sand is now in the Morgan-Bement collection at
Xew York. This is the rarest of all the colors of sapphire or corundum
gems, and is known as Oriental emerald. The specimen is a crystal
20 Am. Jour. Set, IV, Aug. and Sept., 1872.
CORUNDUM GEMS. 19
4 x 2 x 1 J inches ; part of it is transparent, and several very fine gems
could be cut from it, see Plate XII.
Another locality in the same county, interesting, though less prominent,
is the Mincey mine on Ellijay (properly Elegee) Creek, about 2 J miles
northeast of Corundum Hill. Some good ruby corundum occurs here,
together with a peculiar brown or bronze variety, known locally as " pearl
corundum," which shows distinct asterism, both by natural and artificial
light, when the stone is cut en cabochon. In natural light these corun-
dums all show a bronze luster and are somewhat similar to the catVeye,
but in artificial light the star is more distinct. Most of the bronze -corun-
dum is in rough crystals, but some have been found that have the prismatic
faces smooth and well developed, and these are often dark, almost black,
in color. One crystal of this dark kind, found some years ago, yielded
gems § of an inch in diameter. A similar asterism has been noticed in
many of the rubies and sapphires from Cowee Valley, and at several
other points in the State. According to Von Lasaulx, it is some-
times produced by rifts due to the basal parting. These rifts when
examined with the microscope, are seen to be very thin, sharp and recti-
linear, and are parallel to the edge between the prism and the base. In
other cases asterism is undoubtedly due to rutile or other minute crystals
enclosed in the corundum, intersecting each other at an angle of 60°, or in
some similar systematic positions.
At the Cullakenee mine, Buck Creek, in Clay County, masses of emerald
to grass-green amphibolite (also called smaragdite) are found, through
which are disseminated particles of pink and ruby corundum, from the
size of a pea to some as large as hickory nuts. The corundum is not of
gem quality, but the combination of the green and pink makes very
beautiful specimens, and as the rock is hard enough to take a good polish,
it might furnish a decorative or ornamental stone of some value. It has
been introduced for such purposes under the name of ruby matrix.
A similar association of green amphibolite with corundum, sometimes
pink and sometimes dark blue, is found near Elf post-office, on Shooting
Creek, in the same county. Other corundum localities in Clay County are
the Foster mine, near the headwaters of the north fork of Shooting Creek,
and the Herbert mine on Little Buck Creek.
Of late much attention has been aroused by the discovery of rich ruby
corundum in small distinct crystals of a different character from any
others found in the State, and in a different rock. These have been known
as the Cowee rubies, from the locality in the Cowee valley, in Macon
County. It has seemed as though here, at last, true gem rubies, equal to
those of Burma, had been really found, and much interest has been felt in
20 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
the discovery. Thus far, however, no very important results have been
obtained, although some of the stones are unquestionably fine, but most of
them are small (see PI. I).
They are unusually interesting and beautiful as crystals, but many of
them are imperfect. It is claimed, however, that the percentage of
imperfect stones is no greater than it is in the rubies from Burma.
Unfortunately, many of the crystals also have inclusions which mar their
elegance as gems. The exact locality of this very interesting occurrence is
a tract of some 10 square miles lying between Mason's Branch and
the Caler Fork of Cowee Creek, affluents of the Little Tennessee River
some 6 miles below Franklin, Macon County. Many interesting minerals
are found in this area, and there are mica mines there, and mines where
the abundant garnet has been worked for use as an abrasive. The
beautiful rhodolite garnets, found in close association with the ruby
crystals in the gravel and saprolite, will be described separately under
garnet.
The discovery and development of the " Cowee rubies " were first
described in the volumes of the TJ. S. Geological Survey (Mineral
Resources of the United States), in the writer's annual reports on the
Production of Precious Stones, from 1893 to 1896, year by year, and
further in that of 1899.21 Also in 1899, there appeared a full account by
Prof. J. W. Judd, Mr. W. E. Hidden, and Dr. J. H. Pratt22; and the
latter gentleman has since published further accounts in his annual
reports, and in his special bulletins on corundum in the United States.2"
The first published notice in the author's report for 1893, above
mentioned, was of the finding of ruby corundum, in small hexagonal
crystals, flat or tabular, in an alluvial deposit on the Reeves farm, not far
from Franklin, associated with beautiful garnets. The next years report
described the locality as consisting of the valley of a stream, for several
miles, in which the rubies were distributed through a gravel bed from
2 to 10 feet thick, overlain by several feet of surface deposit. — a mode
of occurrence very similar to that in the Mogok Valley in Burma, where
the finest rubies are obtained.
The attention of the author was first called to these rubies by the late
Mr. James D. Yerrington, of New York, who had specimens, both cut
and uncut, that he had received from Mr. Reeves, of Athens. Georgia,
who owned the farm on which they had been found. Two cut gems of
\ a carat each, were set in a flag scarf-pin shown in the Tiffany jewelry
21 Mineral Resources U. S., Ann. Reps. U. S. G. S., 1893, 1894, 1895, 1896. 1899.
22 Am. Jour. Sci., IV, Vol. VIII, Nov. 1899, pp. 370-380.
23 Bulls. U. S. Geol. Survey, No. 180, 1901 and No. 269, 1906.
CORUNDUM GEMS. 21
S
exhibit at the Columbian Exposition of 1893; these were subsequently
unmounted and displayed by the same firm at the Atlanta Exposition of
1895. They now form part of the Tiffany-Lea collection, included in
that of the U. S. National Museum at Washington. A number of others
(see figures), obtained at about the same time, are in the American
Museum of Natural History, New York. A fine series, both of crystals
and cut gems, was shown by the North Carolina Geological Survey at the
recent Expositions at Buffalo, 1901, Charleston, 1901-02, and St. Louis,
1904.
In 1896, the locality was visited and examined by Mr. C. Barrington
Brown, the eminent authority on ruby mining, who had previously pre-
pared an exhaustive report on the Burma region, in conjunction with
Prof. J. W. Judd, for the British Government.
In 1899, as above stated, Professor Judd and Mr. William E. Hidden
published a joint article, with crystallographic notes by Dr. J. H. Pratt.
This account embodied the results of Mr. Brown's visit, of Mr. Hidden's
operations on the ground, and of Dr. Pratt's studies on the crystal forms
and their relations. It had now become clear that the rubies from this
locality occurred in a wholly different association from any other corun-
dum in the State, and the title of the article was " On a New Mode of Oc-
currence of Euby in North Carolina." The surrounding rocks are schists
and gneisses, often containing corundum, but in elongated crystals and
not of gem quality. Only a few miles away are the dunite outcrops of the
Culsagee and other localities, already described. But at Cowee the rock
is wholly different, and the forms of the crystals also. The first accounts
had reported a limestone as the probable source of the valley deposit,
and even as the matrix of the crystals, as is the case in Burma. But
further study had disproved this statement. Underneath the ruby-bearing
gravel, comes a soft decayed rock to which the name of saprolite has been
given, — a result of the decomposition of basic igneous rocks, in. place.
This is sometimes many feet in thickness, but gradually passes downward
into the unaltered condition of the same rocks. Trial shafts show that
this change begins from a depth of some 35 feet, when portions of the
unaltered rock begin to be met with. The original rock, when reached,
proves to consist of several related varieties, comprising amphibolite,
hornblende-eclogite (garnet-amphibolite of some authors), and a basic
hornblende-gneiss, with some feldspars (labradorite and perhaps anor-
thite). Some of these rocks are doubtless the source of the rubies strewn
through the saprolitic material and the overlying gravel, though their
actual occurrence in the undecomposed rock has not vet been proved.
The crystals are distinct from any others found in North Carolina, but
22 HISTORY OF THE GEMS FOUND IN NORTH CAROLIXA.
resemble in form those from Yogo Gulch, Montana (the sapphire variety)
which are taken from true igneous dikes; and these flat and tabular
hexagonal forms are regarded by students of crystallography as character-
istic of corundum that has solidified from a molten igneous rock.
Another corundum occurrence in saprolitic rock, but the crystals blue
and more prismatic, is noted by Dr. Pratt at the Seed, or Watauga mine,
6 miles east of Franklin; and red, sometimes ruby, corundum is found
in old stream gravels near West Mills; both of these are in Macon
County. A number of minor occurrences are known throughout the
general region, where there are small saprolitic areas.
There are many other localities of corundum in this group of counties,
some of the more important or promising of which may be simply men-
tioned here. In Macon County, besides the important occurrences already
described, corundum appears at Glenville, in chlorite schist; at Xona,
on Thumping Creek, in nodules and flat crystals in gneiss; on Hickory
Knoll Creek at an elevation of 4,000 feet on Fishhawk Mountain, in
dunite ; and at the Coweeta mine, of pink color in greenish cyanite. Of
late, the emery variety has been found, and to some extent worked, at
several points near Fairview Knob, in a basic magnesian rock, the prin-
cipal mine being the Fairview, near North Skeener Gap, and the Waldroop
mine on Dobson Mountain.
Jackson and Transylvania counties have numerous corundum localities,
notably in the region along their border, where the town of Sapphire has
been named, and the appellation of the Sapphire country is frequently
used. Here are found many outcrops of peridotite, with a general X.E.-
S.W. course, and frequently associated with corundum. One locality that
gives some promise is the so-called gem mine on the property of Dr.
Grimshawe, of Montvale. This has been known and to some extent
worked, for many years. Eubies of good color, from which a number of
fine but very small stones have been cut, have been found here in the
gravels of the stream, together with blue and yellow corundum of gem
quality. By following up the gravels the corundum was located in a small
vein in the decomposed peridotite.
At the Sapphire and Whitewater mines, near Sapphire, fragments of
corundum of a fine blue color have been found, from which small but good
gems have been cut.
Quite large amounts of commercial corundum have been taken out at
the Bad Creek and Socrates mines, and also at the Burnt Bock and
Brockton mines; these two are in Transylvania County, the others being
in Jackson County, and all in peridotite. Other associations in Jackson
County are, along Caney Fork and Chastain's Creek, in chlorite schist;
and at Bett's Gap in translucent grayish-white crystals in gneiss.
CORUNDUM GEMS. 23
In Haywood County, 2 miles northeast of Pigeon river, near the cross-
ing of the Asheville road, and 2 miles north of this, on the west fork of
Pigeon Eiver, at Presley mine, are found some of the finest colored
specimens of blue and grayish-blue corundum, in a pegmatitic dike, and
also near Eetreat post-office (see PI. IV, B). At Newfound Gap, red
corundum occurs in an outcrop of dunite.
Twenty miles northeast of the Presley is the Carter mine in Buncombe
County, where fine white and pink corundum occurs in crystals and in a
laminated form in peridotite. Blue, bluish-white, and reddish varieties
occur at Swannanoa Gap ; and also a little south of the town of Democrat,
corundum appears, — all in the same or similar rock.
Yancey County has several localities, the most noted of which are
Celos Eidge, 8 miles southeast of Burnsville, where crystals occur in a
decomposed gneiss, and Egypt, 10 miles west of the same town, where
white crystals, sometimes mottled with blue, are found directly in the
decomposed peridotite (dunite). This occurrence is noted as of much
interest, by Lewis1 and Pratt,2 for although corundum is very largely
associated with the rock, the crystals are rarely found actually enclosed
in it.
Northeast of these mines, in the line of strike of the whole country
rock, corundum is found in gneiss near Bakersville, in Mitchell County ;
and also southwest, in Madison County, near Marshall, a little north of
where Big Ivy Eiver enters the French Broad; here the rock is amphib-
olite.
Grouped together under the name of the Blue Eidge tract, are a
number of localities where the corundum occurs in long bands of quartzose
schist that belong in and with the gneisses among which they occur. This
was referred to before as a very distinct mode of occurrence, in that the
rocks are altered sediments, and the corundum, a product of metamorphic
action rather than igneous. These corundiferous schists have been traced
for many miles along the crest of the Yellow and Chunkygal mountains.
The content of corundum is very small, and these deposits will not be
important sources for some time to come. Dr. Pratt makes 4 local divi-
sions ; — The Scaly Mountain tract, at an elevation of some 4,500 feet
on the southern and southwestern slopes of those mountains, near the
headwaters of Beech Creek, a tributary of the Tallulah ; the Foster tract,
just over the line in Georgia; the Yellow Mountain tract, on the northern
slopes of those mountains ; and the Chunkygal tract, near the headwaters
of Sugar Cove Creek, on the western slopes of the mountains. The first
1Bull. 11, N. C. Geological Survey.
2 Bull. 269, U. S. Geological Survey.
24 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
two have been worked somewhat, by the Corundum Mining & Manufac-
turing Co., of Philadelphia. These localities are all near the southern
border of the State, and pass over into Rabun County, Georgia.
The Piedmont Counties. — As was stated above, corundum was early
found at some points east of the mountains ; and the references to discov-
eries and collecting by Dr. C. L. Hunter, Prof. J. A. Humphreys, and
Prof. Brumby of Columbia, S. C, antedate the Civil War by about 10
years. Since the new epoch of mineral development set in after the
return of peace, further discoveries have been made, all of interest, but
none as yet of importance. Mr. J. A. D. Stephenson obtained fine
hexagonal prisms of pale brown corundum at Belt's Ridge, near States-
ville, Iredell Co., and some crystals of fine colors from other neighboring
points. Prof. Lewis mentions a black corundum in amphibolite, on the
Hunter farm, 8 miles north of Statesville, another occurrence in the
same rock, at the Acme mine, and a pink corundum in cyanite at the
Collins mine, both in the same vicinity. An old locality, especially noted
by Professor Humphreys, is Shoup's Ford, in Burke Co., where the
corundum is associated with fibrolite, which sometimes surrounds or
encloses the crystals, forming what Professor Humphreys described as
"pods." In Gaston County, bine corundum occurs with quartz and
mica, at Crowders Mountain and Chubbs Mountain; the latter is the
source of the Brumby specimens in 1852; it was then known properly
as Clubb Mountain, named from an old resident and Revolutionary
patriot.
Corundum in grayish-blue crystals in garnet-bearing schists and gneisses
is reported from points along the ridge stretching from Carpenter's Knob,
northwest, on the borders of Burke, Catawba, and Cleveland counties.
CHAPTER IV.
GEM MINERALS OF THE PEGMATITIC DIKES.
In the pegmatite veins of North Carolina are found so many minerals
of gem value 1 that a short description of these dikes is given here.
These pegmatitic veins are interesting not only from a commercial
standpoint on account of the value of the mica obtained, but also from a
mineralogical' standpoint on account of the variety of minerals that they
sometimes contain.
In character these pegmatitic dikes are very similar to a granite and
have sometimes been called " coarse granite " and, if we could conceive
of the constituents of a granite magnified a hundred times or more,
we would have an appearance that is very similar to a pegmatitic dike.
The main mineral constituents of these dikes are quartz, feldspar, and
muscovite mica in varying proportions, sometimes being nearly equally
distributed while in others sometimes one and again another will pre-
dominate. Sometimes the feldspar, quartz, and mica have separated out
in rather small masses while at other times they have separated out on a
larger scale and are more or less crystallized.
The associated minerals that occur in these dikes vary with their occur-
rence and while in some there is a great variety of •them, in others they
are very rare. The pegmatitic dikes that are observed in North Carolina
have furnished the greatest variety of accessory minerals, 45 having been
observed from the different veins, at a number of which over 20 different
minerals have been observed. Of these accessory minerals the garnet
(either andradite or almandite) is by far the commonest and is often the
only accessory mineral observed.
The accessory minerals in these pegmatitic dikes are usually well
crystallized and a number of them are gem minerals. The following is a
list of the minerals that have been identified in the mica-bearing
pegmatitic dikes in North Carolina and they are given approximately
according to their relative frequency of occurrence :
Quartz (massive, crystallized and Zoisite (var. thulite).
smoky). Menaccanite.
Albite, Feldspar. Rogersite.
1 Joseph Hyde Pratt in " The Southland," Asheville, North Carolina, August, 1001, pp.
120-121.
26
HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
Microcline, Feldspar.
Oligoclase, Feldspar.
Orthoclase, Feldspar.
Kaolin.
Beryl (Emerald, yellow, and aqua-
marine).
Muscovite, Mica.
Biotite, Mica.
Essonite, Garnet.
Almandite, Garnet.
Andradite, Garnet.
Tourmaline.
Apatite.
Columbite.
Allanite.
Epidote.
Samarskite.
Gummite.
Autunite.
Pyrite.
Magnetite.
Hatchettolite.
Fergusonite.
Uraninite.
Uranotil.
Phosphuranylite.
Monazite.
Zircon.
Pyrrhotite.
Hematite.
Limonite.
Rutile.
Molybdenite.
Opal (var. hyalite)
Enstatite.
Actinolite.
Cyanite.
Gahnite.
Chabazite.(?)
Graphite.
Pyrophyllite.
Of the minerals given in this list the following have been found of
sufficient purity to be a source of gems :
Essonite. Albite.
Almandite. Oligoclase.
Beryl. Orthoclase.
Quartz. Gahnite.
The following of these pegmatite occuring minerals are precious stones :
Albite, Feldspar.
Almandite, Garnet.
Beryl (Emerald, yellow, and aqua-
marine).
Cyanite.
Essonite, Garnet.
Opal (var. hyalite).
Pyrite.
Quartz, (massive, crystallized and
smoky).
Menaccanite.
Microcline.
Oligoclase, Feldspar.
Rutile.
Zircon.
The following are radio-active :
Allanite. Monazite.
Autunite. Phosphuranylite.
Columbite. Rogersite.
Fergusonite. Samarskite.
Gummite. Uraninite.
Hatchettolite. Uranotil.
Menaccanite.
Plate No V
Smoky quartz
( cairngorm stone),
AlexanderCounh/, North Carolina
iu 1 1 late d Quariz.
Alexander County,
North Carolina
Elutiloted Quartz
Alexander County,
North Carolina
D E
Amethyst
Henry Lincoln County
North Carolina.
Amethyst.
TesantyCn
Smith Bridgelbwnship,
Macon Cbunty, NorthCaioIina.
i by'lhliei Prang Art lo
.Vepsrw undei II
GEM MINERALS OF THE PEGMATITIC DIKES. SJ'7
The following are commercial minerals :
Graphite. Muscovite (mica).
Kaolin. Orthoclase.
Magnetite. Pyrophyllite.
It is the breaking down of these veins that form many of the smaller
often microscopic minerals found in the detritis of the gold veins.
THE FELDSPARS.
Several interesting varieties of feldspar occur in North Carolina,
among which the following may be especially noted as the ones which are
of importance as gem material.
Orthoclase. — A very interesting variety of sunstone was found by J. A.
D. Stephenson at the quarry in Statesville, N. C; the reflections are as
fine as those of the Norwegian, but the spots of color are very small.
Several hundred dollars' worth from this locality have been sold as gems.
Microcline. — This feldspar is closely related to orthoclase; it is some-
times of a very beautiful light green color, and is then known as amazon-
stone, and valued for cutting and polishing for ornamental purposes.
Several localities in North Carolina furnish this mineral, especially the
Eay mica mine, Yancey County.
Oligoclase. — In December, 1887, specimens of feldspar were sent to the
writer2 by Daniel A. Bowman, who had found them at a depth of 380
feet in the Hawk Mica mine, 4 miles east of Bakersville, N. C. They
proved to be a variety of oligoclase, remarkable for its transparency. The
clearest piece measured 1 by 2 by 3 inches. One of the two varieties
is of a faint window-glass green color, and contains a series of cavities,
surrounded and fringed by tufts of white, needle-shaped inclu-
sions called microlites; these tufts vary from 1/50 to 3/50 inch (0.5 to
1.5 millimeter) in diameter and are quite round, resembling those that
are occasionally present in the Ceylonese moonstone. The wonderful
transparency of the oligoclase and the whiteness of the inclusions give
the whole mass a striking resemblance to the lumps of glass so commonly
obtained from the bottom of a glass-pot. It was mistaken for this until
its highly perfect cleavage was noticed. Recently some material of a
slightly different character has been obtained at the mine. Cleavage
masses of a white, striated oligoclase, 3 inches long, were found containing
nodules about f inch to f inch (10 to 15 millimeters) across, which were
as colorless and pellucid as the finest phenacite and entirely free from
2 See Mineralogical Notes, by George F. Kunz, Am. Jour. Sci., Ill, Vol. XXXVI, p. 222,
Sept., 1888.
28 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
the inclusions found in the greenish variety. This translucent variety,
like the other, shows no striae.
The following analysis by Prof. Frank W. Clarke, made from a faint
green variety, shows it to be a typical oligoclase. The specific gravity was
determined to be 2.651. This has been cut into a transparent gem, and
may be advantageously used for spectroscope, microscope, and other lenses.
Silica 62.60
Alumina 23.52
Ferric Oxide 08
Manganous Oxide trace
Lime 4.47
Potassa 56
Soda 8.62
Loss by ignition 10
99.95
Labradorite (Opalescent feldspar). — On the road to Charlotte, Mecklen-
burg County, and near Bakersville, Mitchell County, specimens showing
a slight blue chatoyancy are found. This domestic labradorite is scarcely
used at all in the arts, as the mineral from Labrador is cheaper and of a
much superior quality, and takes a fine polish.
Leopardite. — This is a rock composed largely of whitish feldspar
(orthoclase and plagioclase), spotted black, perhaps by manganese oxide,
and named from its leopard-like appearance. It is abundant near
Charlotte, Mecklenburg County, and also in Gaston County. It is not
a definite mineral, but a variety of porphyry with disseminated crystals
of quartz, and occurs in large masses as a rock, so that it would furnish
a good ornamental stone, if polished. This variety of spotted feldspar
is peculiar to North Carolina, and has been described in detail in the
report on Building Stones.
The beryl, zircon, and other gem minerals, which are also constituents
of pegmatitic dikes, are described in the following chapters.
CHAPTER V.
QUAKTZ AND OPAL.
Quartz in its various crystalline forms, — rock-crystal, amethyst, and
smoky quartz, — occurs at many points in North Carolina, and in some
cases of fine quality (PL V). The non-crystalline varieties, such as
agate, jasper, etc., have not, on the other hand, been found to any
important extent in the State, until very recently in the chrysoprase
workings near Asheville.
CRYSTALLINE VARIETIES.
Rock-Crystal.- — Much interest was created in 1886, when a remarkable
mass of rock-crystal, weighing 51 pounds, was sent to Tiffany & Com-
pany, New York. It purported to be from Cave City, Va., but was
subsequently traced with certainty to the mountainous part of Ashe
County, N. C.1 The original crystal, which must have weighed 300
pounds, was unfortunately broken in pieces by the ignorant mountain
girl who found it, but the fragment sent to New York was sufficiently
large to admit of being cut into slabs 6 inches square and from half an
inch to an inch thick. This superb crystal, if it had not been broken,
would have furnished an almost perfect ball 4-J or 5 inches in diameter.
It is now in the Morgan Collection at the American Museum of Natural
History, New York. A visit to the locality by the author traced this
specimen to the place of its discovery near Long Shoal Creek, on a spur
of Phoenix Mountain in Chestnut Hill Township. There have also been
found at 2 places, 600 feet apart (about 1 mile from the former locality),
2 crystals, weighing respectively 285 and 188 pounds. The larger of the
2 was 29 inches long, 18 inches wide, 13 inches thick, showing 1 pyra-
midal termination entirely perfect and the other less complete. All these
crystals were lying in decomposed crystalline rock consisting of a coarse
feldspathic granite, and were obtained either by digging or by driving a
plow through the soil. Altogether several dozen crystals have been found
in this vicinity weighing from 20 to 300 pounds each, and future working
will undoubtedly reveal more. These large crystals are often very irregu-
lar and pitted, like many of those from St. Gothard. Of those now in
iProc. Am. Assoc'n Adv. Scl., Vol. XXXV, p. 239, 1886.
30 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
the Morgan-Tiffany collection at New York, the most irregular was 20-|
pounds in weight, with the entire surface rough and opaque like ground
glass, and almost spherical in form, but the interior perfectly transparent.
In a few instances, they had a coating of rich green chlorite that pene-
trated to the depth of an inch. This, when left on the quartz, gave the
cut crystal, after polishing, the effect of a pool of water with green moss
growing on the bottom.
Many beautiful articles have been made from this Ashe County
material. One was an elegantly carved vinaigrette or scent-bottle, exhib-
ited at the Paris Exposition of 1889. A crystal ball 5 inches in diameter,
and a number of art objects, all of American workmanship, made from
the same material, were shown at the Columbian Exposition at Chicago
in 1893, and some of these are now in the Tiffany collection in Higin-
botham Hall, in the Field Columbian Museum in that city. These were
all made in the Tiffany ateliers in New York.
By far the most important piece from this locality, however, was a
magnificent crystal obtained in 1888 by the author at the same locality.
This was worked up into a special design, and exhibited as the finest
piece of American lapidary work ever executed in rock crystal. It was the
most important art object of stone at the great Paris Exposition of 1900,
where it was shown by the makers, Tiffany & Company. It now will form
part of the F. A. Matthiesen memorial gift, lately presented to the
Metropolitan Museum of Art in New York City.
Another North Carolina locality was reported in 1896, by Mr. E. M.
Chatham, who described crystals up to 40 pounds in weight, from Elkin,
in Surrey County. Some large crystals are also known from South
Carolina; and it is probable that a good deal of rock-crystal, capable of
use in the arts, exists in the mountain region of the South.
The report of the finding near Bakersville of transparent crystals of
quartz, weighing 642 pounds and 340 pounds respectively, was premature,
as the specimens proved to be veins of translucent quartzite, with the
crystalline markings of a group rather than of a single crystal. The
clear spaces, which were to be observed only on these crystalline sides,
would hardly afford material for a crystal ball an inch in diameter, and
with this exception they are almost an opaque white, with flaws. Notwith-
standing this error, it is certain that some localities in North Carolina
have yielded larger masses of clear rock-crystal than any other State
in the Union, until the recent developments in Calaveras County,
California.
In Alexander and Burke counties, N. C, crystals of white as well as of
smoky quartz have been found, in which were spaces that would cut into
.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE VI
A. QUARTZ CRYSTALS (SMOKY) NATURAL SIZE, ALEXANDER COUNTY, N. C.
li. AMETHYST, LINCOLN COUNTY, N. C.
QUARTZ AND OPAL. 31
clear crystal balls of from 2 to 2-| inches (PI. VII, A). One of these
from Alexander County, measuring 2 3/16 inches, is in the State Museum
of Natural History at Albany, N. Y. A very interesting bead made of
rock-crystal, fluted and drilled from both ends, is in the collection of
A. E. Douglas, in New York City. It is evidently native work, as it is
improbable that foreign traders would use white rock-crystal beads, when
glass would answer the purpose as well.
The Indians who lived in North Carolina previous to the advent of
the white man occasionally noticed quartz crystals, as is shown by some
being found in the mounds. They also realized the beautiful cutting edge
that this material would possess if it were chipped in the form of an arrow
point; and so they used up great quantities of the white quartzite for this
purpose, and occasionally a transparent piece of quartz, either white or
smoky. Many such objects, — of the chase or of war, — made of this
beautiful material have been found, and are to be seen in our museums.
Within the past 10 years, however, the demand for these transparent
arrow-heads has increased, until the demand has so much exceeded the
supply that some of the inhabitants, especially in Mitchell County, with
remarkable cupidity and cleverness, have chipped arrow-points out of
quartz crystals. These are in many ways quite as beautiful as the Indian
work, but have no archaeological value, of course, though they are to some
extent sold as articles of ornament.
The highly modified crystals from White Plains, in Surrey County,
and Stony Point, Alexander Count}', and also from Catawba and Burke
counties, N. C, are worthy of note as being crystallographically un-
equalled anywhere, and as having formed the subject of special memoirs
by Dr. Gerhard von Path2 (Pis. VI, A and VIII, A). A beautiful
opalescent quartz has been found in Stokes County.
Amethyst (Purple Variety of Quartz.) — An almost unique gem in the
collection of the United States National Museum at Washington is a
piece of amethyst found at Webster, N. C, and deposited by Dr. H. S.
Lucas. The present form is just such as would be made by a lapidary in
roughly shaping a stone, preliminary to cutting and polishing it. It was
turtle-shaped when found, though the shape was unfortunately destroyed
by chipping, and was said to have borne marks of the handiwork of
prehistoric man. It now measures 3f inches (6 centimeters) in width,
1-J- inches (4 centimeters) in thickness, and weighs 4f ounces (135.5
grams). It is perfectly transparent, slightly smoky, and pale at one end,
and also has a smoky streak in the center.
2 Naturw. Verein, Westphalia, 1888.
4
32 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
In Haywood County a number of crystals of amethyst have been
secured, some of which were cut into very fine gems.
In 1894 Mr. T. K. Brunner, of Kaleigh, reported a yield of amethysts
from Catawba, Macon, Wake, Lincoln, and other counties in the State;
and in 1898 he stated that large amethysts of good color were still found
in Lincoln County, together with smoky and lighter colored varieties.
In 1901 there was a decidedly promising effort to prosecute mining for
amethysts on a commercial scale at Tessentee, on the creek of that
name, in Smith Bridge Township, Macon County. Here a large vein of
crystalline quartz occurs in an altered pegmatite. The development
during the year was entirely in a kaolinized rock, in which the amethyst
crystals, ranging from \ inch to 3 inches in length, were found loose with
the quartz and mica in the kaolin. The entire vein was exposed to the
depth of 20 feet by a landslide. It would appear that further working
should disclose the amethysts in the rock. The crystals are light and dark
in color, and the dark spots are often of the deepest purple. Xo finer
amethysts have been discovered in this country, and several thousand
dollars worth of crystals were sold as the proceeds of the first development
work.
Amethyst crystals, often of great beauty and of much crystallographic
interest, have been found in various parts of the State, sometimes in
remarkable quartz groupings, such as the so-called capped crj'stals, with
purple tops raised upon slender stilt-like white crystals ; others with rare
faces, and then again enclosing water, especially from Lincoln County
(see Pis. V, VI, B, and VII, B).
Smoky Quartz. — At Taylorsville and Stony Point, North Carolina, a
number of clear pieces of this material have been found that cut fair
stones weighing over an ounce each. In Alexander, Burke, Catawba, and
adjacent counties, smoky quartz crystals which would afford fine gems are
frequently met with. They are generally from 1 to 5 inches in diameter,
sometimes of a citron or light yellow color, and often in groups weighing
up to 100 pounds and over, quaintly grouped and often very clear.
Crystals weighing as much as 40 pounds have been taken from the vicinity
of Elkin, in Surrey County. Smoky and citrine quartz abound also in
Iredell and Mitchell Counties.
At Stony Point, near Hiddenite post-office, Alexander County. X. C.
have been found from time to time in the gneissoid rocks, pockets of quaitz
crystals varying from absolute pellucid and transparent to a dark smoky
color. These are of wonderful brilliancy and purity, and range from an
inch in length to a large size ; but they are particularly remarkable from
the fact that the faces of the crystals are highly and peculiarly developed,
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE VI]
A. SMOKY QUARTZ CRYSTALS, 7/16 NATURAL SIZE, HIDDENITE P. 0., ALEXANDER COUNTY, N. C.
3'
Q
2
o
2
H
ft
to
2
to
B. QUARTZ CRYSTALS, WITH AMETHYST TIPS, NATURAL SIZE, LINCOLN COUNTY, N. C.
QUARTZ AND OPAL. 33
sometimes with great complexity (PL VI, A). They have furnished the
subject for several monographs on the crystallography of quartz, notably
those by Dr. Gerhard von Eath, of Bonn, and by Dr. Gill, of Cornell
University. Some of the large complex groups are very interesting from
their remarkable twinning-masses from 150 to 200 pounds, being made up
of many crystalline faces, while in general contour a single large crystal.
They stand quite unique as examples of beautiful color and marvelous
crystallization (see Pis. V and VI, A).
The remarkable smoky crystals with included cavities, from Alexander
County, are referred to further on, under quartz inclusions.
Hose Quartz. — Specimens of rose quartz from Dan Eiver, Stokes
County, N. C, show a beautiful opalescence, and the existence of like
quartz, as well as asteriated quartz, in two other counties, Iredell and
Cabarrus, was determined in 1894.
Quartz Inclusions (sagenite). — North Carolina has yielded more of
this material for gem purposes than all other American localities together.
Eutilated quartz of unexcelled beauty, the rutile brown, red, golden or
black, has been brought to light in many places in Eandolph, Catawba,
Burke, Iredell, Jackson, and Alexander counties, especially the last, where
in 1888 crystals of quartz, 3 inches in length, and filled with rutile the
thickness of a pin, were secured at Stony Point (PL V) . Beautiful series
of these formerly in the collection of J. W. Wilcox, of Philadelphia, are
now in the Morgan-Bement collection in New York. In 1901, fine ruti-
lated quartz, well crystallized and perfectly transparent, was developed,
together with handsome garnets, in the monazite mines near Shelby,
Cleveland County.
Hornblende in quartz is reported as found in Burke, Alexander, and
Iredell counties.
Mining operations at Stony Point, N. C, have brought to light a
number of crystals 4 by 3 inches, and masses of quartz 6 by 3 inches,
some of the former filled with what appears to be asbestos or byssolite,
forming an interesting and attractive material susceptible of being cut
into charms and other objects. Magnificent polished specimens are in
the Morgan-Tiffany and Morgan-Bement collections. The inclosures of
what is seemingly gothite in minute red, fan-shaped crystalline groups
or tufts, form also a beautiful and interesting gem stone.
Among other inclusions, some of which might be utilized for gems,
the following may be mentioned from North Carolina : Quartz, including
scales of hematite from King's Mills, Iredell County; quartz containing
crystals of green spodumene (hiddenite) from Stony Point; inclusions of
34 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
muscovite mica, that are green when viewed through the side of the prism,
and of green chlorite, from several other localities in Alexander County.
A remarkable specimen of this kind, that was a " nine-days wonder "
some years ago, was the so-called Gibsonville emerald. This was a stone
weighing 9 ounces, plowed up near Gibsonville, Guilford County, which
was pronounced a genuine emerald by some local expert, who tested it,
and with the microscope showed that it contained various small diamonds.
Its value was estimated up in the thousands, and $1000 was reported to
have been refused for it by its owner, who, as it was believed to be the
largest known emerald, expected that it would bring him a fortune.
Being, therefore, too valuable to be be entrusted to an express compan}*,
he put himself to the expense of a trip to New York, where his prize
proved on examination to be a greenish quartz crystal, filled with long
hair like crystals of green byssolite or actinolite, on which were series
and strings of small liquid-cavities that, glistening in the sun, had led to
the included diamond theory. The best offer that he received for the
stone was $5.
Fluid Inclusions. — In March, 1882, Mr. William E. Hidden described
and illustrated before the New York Academy of Sciences some unpar-
alleled specimens obtained at Stony Point, Alexander County — the
emerald locality elsewhere noted.3 Here some 400 pounds of choice large
crystals of smoky quartz were taken out of a " pocket " in a quartz vein,
besides much of less fine quality. These crystals were filled with cavities
containing a clear lustrous fluid, and of extraordinary size, those of an
inch long being not uncommon, and some of double that length. The
largest was 2J inches by J of an inch. So abundant were they that at
times the crystals seemed to be made up of thin walls of quartz, separating
a multitude of elongated cavities, parallel to the rhombohedral or pris-
matic faces of the crystals (PL VIII, B).
It is a matter of great regret that such unique specimens could not
have been studied with the minute care given by Professors Dana and
Penfield to those of Branchville, Conn. But now comes the singular
conclusion of this account. The whole body of these crystals, carefully
taken out and put aside as great treasures, were shattered into fragments
in a single night, by the temperature falling below the freezing point.
The contained fluid was evidently, as in the Branchville quartz, principally
water, and its expansion in freezing destroyed the entire body of speci-
mens. Those with few cavities exploded with sharp reports, and pieces
were blown as much as 15 feet away. Those filled with small cavities were
3 On a Phenomenal Pocket of Quartz Crystals ; Trans. N. Y. Acad. Sci., March, 1SS2.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE VIII
E
o
I
2
3
td
e
A. GROUP OF QUARTZ CRYSTALS, PARALLEL CRYSTALLIZATION, S/% NATURAL SIZE, LINCOLN CO., N. C.
GROUP OF QUARTZ CRYSTALS, ENCLOSING CLAY AND WATER, $/$ NATURAL SIZE, BURKE COUNTY, N. C.
QUARTZ AND OPAL. 35
reduced to little heaps of fragments frozen together in a coherent mass.
All that remained for the illustration of Mr. Hidden's paper before the
Academy, were flakes of flat pieces, parallel to the faces of the rhombo-
hedron, and filled and clouded with elongated and often rod-shaped
cavities, in great numbers and of conspicuous size.
So-called quartz pseudomorphs after calcite cleavages occur at a locality
2 or 3 miles northeast from Eutherfordton, Eutherford County, and
frequently contain irregularly shaped cavities filled with water, which,
if broken out in good shape, could be utilized as curious ornaments. This
variety of quartz was also found by J. A. D. Stephenson in Iredell County.
This occurrence was named and described by Mr. William E. Hidden of
New York, and shown to be due simply to quartz filling irregular cavities
between the mica crystals in a pegmatite rock. It is known as "box
quartz."
NON-CRYSTALLINE QUARTZ.
As was stated above, these varieties have not been very prominent in
North Carolina.
Chalcedony. — A rich fawn and salmon colored chalcedony has been
obtained near Linville, in Burke County, and fine agates and chalcedony at
Caldwell's, Mecklenburg County, near Harrisburg and Concord, Cabarrus
County, and in Granville and Orange counties, and at some other localities
in the State. A fine green-colored variety intermixed with black horn-
blende, that would afford gems an inch across, was found some years ago
in Macon County, and moss agate near Hillsborough, in Orange County.
Chrysoprase. — This valuable variety of chalcedony, colored green by
oxide of nickel, has recently been found in Buncombe County, near
Morgan Hill, about 16 miles from Asheville.4 It appears in several
parallel seams or veins, having a general N.E.-S.W. course, and within
a few feet of each other. At the surface, the color was pale green, but as
the rock was opened down to some 4 feet, the tint became deeper and
richer. Only a little test work has yet been done, and the extent and
commercial value of the material cannot at present be determined. The
stone polishes very well, and if darker in color the deposit would have
considerable value.
Jasper. — In North Carolina fine jasper, banded red and black, is found
in Granville and Person counties ; bright brick-red and yellow at Knapp's,
Eeed's Creek, Madison County; at Warm Springs; at Shut-in-Creek in
4Min. Res. U. S., 1902, p. 57 (U. S. G. S. report).
36
HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
Moore County; also in Wake County, and elsewhere. Black jasper
(basanite) also occurs somewhat, and a beautiful spear-point, 5 inches
long, and a number of arrow-points, made from this material, have been
found near Statesville.
OPAL.
Opal has been found but very sparingly in North Carolina and, with
the exception of the hyalite variety, the only specimen that has been found
was near Asheville, Buncombe County, and is of a delicate pink color.
Hyalite. — This mineral has been found at the Culsagee Mine, Macon
County; the Carter Mine, Madison County; near Concord, Cabarrus
County; in Burke County; and in limonite geodes found in the decom-
posed dunite near Elf on Shooting Creek, Clay County. Nowhere,
however, is it of importance, though its presence is of scientific interest.
CHAPTER VI.
BEEYL GEMS AND SPODUMENE (HIDDENITE).
BERYL (EMERALD, AQUAMARINE, GOLDEN" BERYL ).
This gem, chemically a silicate of alumina and glucina (or beryllia)
and ranking among the most valuable of precious stones, is found quite
extensively in North Carolina. Its commoner variety, beryl, occurs at
many places in the State, and sometimes of beautiful gem quality; these
are the aquamarines, blue to light green and the yellow or golden beryl.
We will first treat of the precious variety, emerald.
Emerald Beryl. — Very few genuine emeralds have been found in the
United States; and a number of reported specimens, assumed to be
such, have proved upon examination to be only deep green beryls. The
true emerald owes its color to a minute amount of oxide of chromium.
Some beryls are of a very rich light green, and closely resemble emerald,
so that they may easily be regarded as such; but they lack the depth of
color so valued in the real emerald (see Pis. Ill and IX). The chief
localities are Alexander and Mitchell counties, N. C, where emeralds, or
beryls suggesting them occur. In the former it has been found at several
different points, with quartz, rutile (some of the finest known), dolomite,
muscovite, garnet, apatite, pyrite, etc., all in fine crystals. One of these
places, Stony Point, is about 35 miles southeast of the Blue Kidge, and 16
miles northeast of Statesville, N. C. The surface of the country is rolling,
the altitude being about 1000 feet above sea level. The soil, which is not
very productive, is generally a red, gravelly clay, resulting from the
decomposition of the gneissoid rock, and under these circumstances it is
easy to find the sources of minerals discovered on the surface. Prof.
Washington C. Kerr's theory of the " frost-drift " is well illustrated by
the conditions that prevail throughout this region. The unaltered rock
appears at Stony Point at a depth of 26 feet and is unusually hard,
especially the walls of the 'gem-bearing pockets.
An exceptionally clear and reliable account of the search for minerals
in Alexander County which resulted in the final uncovering of the import-
ant emerald and beryl deposits of Stony Point, has been given by the
38 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
developer of the first emerald mine in this country, William E. Hidden/
in 1881, and we cannot do better than quote his words. He writes :
Sixteen years ago, the site of the mine now being worked was covered
with a dense primitive forest. Less than 10 years ago (1871), this country
was mineralogically a blank; nothing was known to exist here having any
special value or interest. Whatever we know of it to-day is due directly or
indirectly to the earnest field work done here in the past 7 years by
J. A. D. Stephenson, a native of the county, now a well-to-do and respected
merchant of Statesville, N. C. Under a promise of reward for success, he
engaged the farmers for miles around to search carefully over the soil for
minerals, Indian relics, etc., and for several years he enjoyed surprising
success in thus gathering specimens. The amount and the variety of the
material gathered in this way was simply astonishing, and his sanguine
expectations were more than realized. To be brief .... I will state that
from a few localities in the county Mr. Stephenson would occasionally procure
crystals of beryl of the ordinary kind, but now and then a semi-transparent
prism of beryl, having a decided grass-green tint would be brought to him.
These the farmers named " green rocks " or " bolts," and became the principal
object of the people's searchings. Mr. Stephenson had told them that a
dark green beryl would be valuable if clear and perfect, would in fact be
the emerald and for them to search more carefully than ever to find one.
Surely, he had informed the people aright and had given them a rara avis
to look for. It is sufficient to say that within a period of about 6 years
there was found on 3 plantations in this county, loose in the soil, a
number, say 10, of veritable emeralds, none of which, however, were dark-
colored or transparent enough for use as gems. All of these specimens went
into Mr. Stephenson's collection, with the single exception of one very choice
crystal obtained at that locality by the late John T. Humphreys, which
crystal is now in the New York State Museum at Albany, after first being
in the collection of the late Dr. Eddy, of Providence.
The following historical account is from unpublished notes on North
Carolina gems, prepared for the author hj Mr. Stephenson himself in
1888:
The first beryl I collected suitable for cutting, was found early in 1875, at
the locality now known as the Emerald and Hiddenite mine. It was a
beautiful aquamarine, but only partly suitable for cutting. A few weeks
later, I obtained at this locality my first emerald; it was small and rather
opaque, but of fine color, and the file-like markings on its planes were very
distinct. During 1876, I collected two others at the same locality. . . . Dur-
ing 1877, Mr. I. W. Miller brought me 2 emeralds found on his mother's
farm, 2 miles northeast of the Emerald and Hiddenite mine. They were
of good color and quite transparent, but very rough on the surface. This
promising locality is still undeveloped.
1 The Discovery of Emeralds in North Carolina, by W. E. Hidden. Privately printed,
8vo., 4 p., 1881, and also Trans. N. Y. Acad. Sci., 1882, pp. 101-105.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE IX
y
2
*.-,..
*
1. BERYL (EMERALD), ALEXANDER COUNTY, N. C.
2. BERYL (EMERALD), STONY FOINT, N. C.
3. BERYL, ALEXANDER COUNTY, N. C.
4. BERYL (EMERALD) WITH RUTILE, ALEXANDER COUNTV, N. C.
5. BERYL CRYSTALS, GROUP.
6. BERYL (EMERALD) ON QUARTZ, STONY POINT, N. C.
BERYL GEMS AND SPODUMENE ( HIDDENITE). 39
During .... 1883, Mr. J. O. Lackey brought me 36 small emeralds, ....
found in a vein of dark mica on his farm a short distance southwest of
the Emerald and Hiddenite mine. One or two other occurrences in the
same region are also reported in these notes.
In July, 1880, Mr. Hidden undertook to follow up the field-work of
Mr. Stephenson systematically, by engaging men to dig a series of ditches
on a selected site, where at least half a dozen pale beryls had been uncov-
ered by a farmer while plowing. These ditches were dug in different
directions, so as to cut the strata of the prevailing country rock (gneiss)
at various angles. After this work had been carried on for 5 weeks
without success, a so-called " blind vein " or pocket was discovered at a
depth of 8 feet. Only a few emeralds, and those of small size, were
found in this pocket, but outnumbering the emeralds 50 to 1, emerald-
green spodumene was brought to light, which later received the name of
hiddenite from Dr. J. Lawrence Smith, of Louisville, Ky., who was the
first to determine its true chemical nature (PI. III). By further work,
eleven other like pockets were opened during the year, within an area of
40 feet square, all carrying emeralds in small quantities, and three
besides the first containing hiddenite or the spodumene emerald also.
Other pockets were found that yielded quartz, rutile, monazite, and
mica crystals of great beauty. In others the walls were covered with
finely crystallized dolomite and calcite and transparent apatite, as well
as the former minerals.
The gem-bearing " pockets " referred to are expansions of quartz veins
that traverse the gneiss rock of the region, having generally an east and
west course and a dip toward the north. They are usually quite narrow,
but on being followed downward, are found to widen out occasionally and
form these -cavities, which may be several inches wide and a foot or more
in length, or in rare cases much larger. There are other quartz veins
also, of more irregular course, which do not appear to develop these
cavities or yield any of the gems. The gneiss rock decomposes in place
to a depth often of many feet; and then the quartz crystals and pieces,
the mica and beryls or emeralds, and in short all the harder minerals of
the veins and pockets, are left lying in the soil formed by the decayed
and disintegrated gneiss. The presence of these minerals on or near the
surface, therefore, serves to those who understand their source, as an
indication or " sign " of the presence of such veins in the rock beneath.
This was the principle, as has been shown, that guided Mr. Stephenson
in his pioneer work.
In 1881, a corporation called the Emerald and Hiddenite Mining Com-
pany was organized to work the property at Stony Point, and prosecuted
40 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
the search for gems irregularly, for periods varying in length, for several
years. Since 1885, however, but little has been done, owing to some legal
disputes as to the property.
The largest emerald crystal found during this mining work was 8-J
inches in length and weighed nearly 9 ounces (PL III, p. 8). It is
now in the Morgan-Bement collection at Xew York. This was one of
nine crystals contained in a single pocket, all excellent in color and
partially transparent, but somewhat flawed. One was 5 inches in length
and others were over 3 inches (PI. III).
One of the most noteworthy gems cut from the product of this mine
was from a crystal found in a pocket at a depth of over 43 feet. Its color
is a pleasing light green and it weighs 4 23/32 carats. In 1887, at a
depth of about 70 feet, another crystal was obtained that yielded a cut
stone of 5 carats. Both of these are too light in color to rank as fine
gems. The two largest, and a series of the smaller ones, went into the
cabinet of Clarence S. Bement, now the Bement-Morgan collection in
the American Museum of Natural History. Some fine ones are also in the
British Museum. The rich emerald color in many of these crystals is
confined to a border from 2/100 to 3/100 of an inch in thickness
around the edge and near the termination of the crystals. If this edge
were thicker, fine gems could be cut from it.
The value of the emeralds in this deposit was relatively small com-
pared with that of the many slender crystals of hiddenite. Both these
species are in part silicates of alumina, but they differ in the other basic
element present, which, in hiddenite, is lithia, while in the emerald it is
glucina. Both gem stones owe their color to the same substance, oxide
of chromium. The emeralds found in this mine were very rarely without
flaws, while the hiddenite was notably free from such defects, and varied
in shade from a yellowish green to the deepest blue-green, often oddly
combining both extremes of color in the same crystal.
The chemical composition of the emerald beryl is shown in the analysis
given below of a leek-green colored beryl from Alexander County :
Analysis of Emerald Beryl.1
Specific Gravity, 2.703.
Constituent. Per cent.
Silica 66.28
Alumina 18.60
Ferrous oxide 0.22
Beryllia 13.61
Water 0.83
Total 99.54
1 F. A. Genth, Analyst.
BERYL GEMS AND SPODUMENE ( HIDDEN ITE ) . 41
In the soil overlying the rock and resulting from its decomposition,
nine crystals of emeralds were found, later, all doubly terminated and
measuring from 1 to 3 inches (25 to 77 millimeters) in width. The latter
crystal is very perfect as a specimen; it is of fine light green color and
weighs 8 J ounces, or only \ ounce less than the famous Duke of Devon-
shire emerald costal (PI. III). Another crystal measuring 2 \ inches
(63 millimeters) by 11/12 inch (25 millimeters) is filled with large
rhombohedral cavities, formerly containing dolomite. As mineral speci-
mens these are quite unique.
Some peculiar features pertaining to the emeralds and beryls from this
region, are particularly noted by Mr. Hidden.2 " They appear," he says,
" as though filed across the prismatic faces." The basal plane is also often
pitted with minute depressed hexagonal pyramids, that lie with their
edges parallel to one another, and to the edge of the di-hexagonal prism.
Rarely, though, crystals are found with perfectly smooth and brilliant
faces. The emerald color is often focused on the surface and fades
gradually to a colorless central core, which feature is of exceeding interest
when the genesis of the mineral is considered.3 A similar etching or
corrosion appears in beryls from Colorado and those from Pala, California.
A remarkable fact is that we have here a green beryl (emerald) and
emerald green spodumene (hiddenite), and in the Pala, California, mine,
we have lilac spodumene (kunzite) and pink beryls.
Some beryls and emeralds of pale color were also collected by Mr. J. A.
D. Stephenson, 1 mile southwest of the Stony Point deposit and a short
distance from the place where the same mineral was found by Mr.
Smeaton, of New York. Such discoveries tend to show that the deposit
is evidently not the only one, and that there is still encouragement for
future working in this region.
In July, 1894,4 a new locality of true emeralds, in the western part of
the State, was discovered by Mr. J. L. Rorison, a pioneer miner of mica.
and Mr. D. A. Bowman, on the Rorison property, 14 miles from Bakers-
ville, and about the same distance from Mitchell's Peak, Mitchell County.
Here, at an elevation of 5000 feet, on Big Crabtree Mountain occurs a
vein of pegmatite some 5 feet wide, with well defined walls, in mica-schist.
It outcrops for perhaps 100 yards, with a north-and-south strike (PI. X).
This vein carries a variety of minerals besides its component quartz and
feldspar, among these being garnets of a translucent reddish color, and
black tourmaline, the latter abundant in slender crystals; beryls, white,
2 Am. Jour. Sci., III, Vol. XXXIII, p. 505, June, 18S7.
3 See Rep. Dept. Mining Statistics, George F. Kunz, 1903.
4 16th Ann. Rep. U. S. Geol. Sur., Part IV, p. 600, 1894.
42 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
yellow, and pale green; and the emeralds. These last are chiefly small,
1 to 10 mm. wide by 5 to 25 mm. long, but some have been found two or
three times the size of the largest above-named. They are perfect hex-
agonal prisms, generally well terminated with basal planes, and are of
good color, with some promise for gems. They very strikingly resemble
the Norwegian emerald from Arendal.
It will be noticed that the occurrence here is entirely different from that
in Alexander Coiinty, being not in veins of quartz, but in a pegmatite
dike. The latter is the usual situation in which beryls are found, from
New England to the Carolinas, and also the large deposits of mica suitable
for mining. This emerald locality has been lately worked by a New York
company, and, although but few perfectly transparent gems have yet been
obtained, a beautiful ornamental stone has been developed. The crystals
vary from ■§ of an inch to 1J inches in diameter, and are rarely over
1 inch in length. Though not clear, they have rather a fine emerald color,
and penetrate the quartz and feldspar in an irregular manner. This green
and white mixture is very pleasing; and as the feldspar has a hardness of
6.5, the quartz of 7, and the emerald of about 8, the whole can be cut and
polished together. Pieces are cut en caboclion, showing sections of one or
more emerald crystals on the top and sides of the polished stone. The
name of " emerald matrix " is given to this ornamental gem material (see
illustration in Morgan-Tiffany collection) (see PL III). This property,
which was worked quite extensively in 1906 by the American Gem and
Pearl Company, of New York, produced some perfectly transparent crys-
tals of emerald which cut good gems up to f carat in weight.
Far to the southwest of Stony Point and some 50 miles south of the
emerald locality near Bakersville, a second new occurrence was noted in
1897 by Mr. J. Meyer of Charlotte, N. C, who had found near Earle's
Station, in that State, between Blacksburg, S. C, and Shelby, N. C, a
broken fragment of emerald of good color, better than anything observed
from North Carolina, although somewhat flawed ; it was cut into a facetted
stone, of tapeziform, or sub-triangular shape, weighing 4 15/16 carats,
that quite closely resembles the material from the Muzo mine of Colombia.
Aquamarine, Yellow and. Golden Beryl. — This mineral, as above stated,
is found at many localities in North Carolina, and sometimes of quality
fine enough to yield choice gems. It will be noted that beryl localities are
met with on both sides of the Blue Eidge, both in the Piedmont region;
and west of the mountains. Here again, for the development of these
and many other forms of mineral wealth in North Carolina, in the years
following the devastation of the Civil War, a lasting debt of honor is
due to Mr. J. Adlai D. Stephenson, of Statesville, and also to the late G-en.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE X
BERYL GEMS AND SPODUMENE (HIDDENITE). 4 3
Thomas L. Clingman, who after serving as a brave officer in the Southern
army, turned his energies to the cultivation of the arts of peace and the
improvement of the natural resources of his State (see Pis. Ill, IX, and
XI).
Mr. Stephenson published accounts from time to time of his researches
and discoveries, beginning soon after the war, and continuing for a
number of years. A number of beryl localities are noted by Mr. Stephen-
son in the counties of Alexander, Burke, Caldwell, Cleveland, Macon,
Mitchell, and Yancey, some of them yielding choice material (PL IX).
The remarkable discovery of emerald beryls at Stony Point, Alexander
County, has been already described under emerald ; but there are numer-
ous occurrences of beryl in the State, closely resembling those of New
England, both in size and variety. Mr. Stephenson called the attention of
the author to a dark green beryl, weighing 25.4 ounces, part of which
would furnish gems of some size, that was found in January, 1888, near
Russell Gap Eoad, Alexander County, by a farmer plowing. This
locality, about 10 miles from Stony Point, is the largest beryl deposit
affording gems that has been opened in North Carolina. It is noteworthy
that the highly modified beryls of this region occur rarely, and only when
associated with spodumene or albite, and also that the white or pale green-
ish beryls are found with the deepest green spodumene. It has be-
fore been noted that the quartz and beryl of Alexander County are more
highly modified when implanted on the feldspathic layers of the walls of
the pockets. We have here a green spodumene and a green beryl (em-
erald) ; we have the same minerals, rose or lilac colored (kunzite) and
rose beryl, at Pala, California. Two emerald beryls found in 1881, at a
depth of 34 feet, were in a little cavity, the walls of which were almost
covered with crystals of albite twinned parallel to the base. Only four
emeralds were found, averaging about 1 cm. in the three dimensions.
The pocket was free from all decomposition whatever. The crystals
were of good color, transparent, and had their commoner planes well
polished, but they differed to some extent in habit.
Some of the North Carolina beryls, especially the fibrous, green, opaque
beryl from Alexander County, would furnish cat's-eyes, although not very
fine.
A rich yellow crystal was reported in 1888 by Mr. Stephenson, as found
in a quartz boulder, with finely crystallized tourmaline, near Little Eiver
Church, Alexander County. Beryl, resembling the Siberian, occurs in
greenish-yellow and deep green crystals, in the South Mountains, 9
miles southwest of Morganton, Burke County; also in the Sugar Moun-
tains at Shoup's Ford, Dietz's, Huffman's, and Hildebrand's. A rich
44 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
blue-green crystal in quartz was found at Mill's gold mine, Burke County,
and a fine transparent green crystal from that vicinity is now in the
cabinet of M. T. Lynde, of Brooklyn, 1ST. Y. Another Piedmont locality
is at Wells, in Gaston County.
Some of the beryls from the neighborhood of Statesville are of unusual
interest from their crystalline forms; these have been described and in
part figured by Mr. W. E. Hidden.5
Passing to the counties west of the Blue Eidge, several good localities
are known where fine beryls occur, generally in pegmatite dikes, like the
Bakersville emeralds. Clear green beryls have also been obtained at
Balsam Gap, Buncombe County; Carter's mine, Madison County; Thorn
Mountain, Macon County, and at one or two points in Jackson County.
The following, however, are more important:
Blue beryl in fine crystals that afforded fair gems was found near the
Yancey County line, and golden beryl in the same vicinity, as noted by
Dr. Pratt. Some crystals 2 feet long and 7 inches in diameter, with small
clear spots, which would cut into gems, occur 4 miles south of Bakers-
ville, and near Grassy Creek, both in Mitchell County (PI. III). Fine
blue-green aquamarine is known at Pay's mica mine on Hurricane Mt.,
Yancey County.
The Grassy Creek locality, just noticed, has attracted some attention
recently as a source of fine aquamarine. It is situated on Brush Creek
Mountain, Estatoe P. O.,6 Mitchell County. The beryls occur in a
pegmatite dike that cuts across the country rock (gneiss) at a low angle,
instead of conforming to the steep lamination of the latter, as do the
ordinary mica veins. These last are chiefly muscovite, while the dike
consists of quartz and albite, with black mica (biotite), garnet, black
tourmaline, titanic iron and beryls. Most of the latter are opaque and
yellowish, the bright green ones being only occasionally found, and not
always in the dike, but sometimes in the adjacent mica-schist, — as though
a product of contact alteration. The best crystals have a fine aquamarine
tint, and some have yielded very perfect gems of more than a carat in
weight. Some honey-yellow beryls also occur, sufficiently clear for cutting,
but these are rare.
Another locality in Mitchell County, very promising as a source of
aquamarines, is the Wiseman mine at Elatrock, near Spruce Pine P. 0.
Here the beryls occur not in a dike, as in the last instance, but in con-
nection with veins of muscovite mica that run with the gneiss rock.
5 Am. Jour. Sci., Vol. XXII, August, 1881.
6 J. H. Pratt. Jour. Elisha Mitchell Sci. Society, Vol. XIV, Part 2, 1897, p. 80.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE XI
BERYL CRYSTALS, GROUP, NATURAL SIZE, BURNSVILLE, N. C.
BERYL GEMS AND SPODUMENE (HIDDENITE). 45
Several colors are found here ; some are of fine aquamarine tint, and have
yielded very perfect gems of more than a carat; less frequently they are
honey-yellow, with portions clear enough to be cut; while rich blue ones,
equal to any of those from Brazil, have also been obtained in the course
of the past 15 years, first by desultory working and then by the most
systematic operations under the American Gem Company, of New York
City. Large quantities, — thousands even, — of magnificent blue gems
weighing from 1 to 20 carats, have been taken out here. (See PL II.)
At the Littlefield mine, on Tessentee Creek, Macon County, clear aqua-
marines have been obtained which have cut into beautiful gems.
At the Charleston Exposition of 1901,7 Dr. J. H. Pratt exhibited,
among other choice minerals of North Carolina, a crystal of golden beryl
1J inches in diameter and %\ inches long, obtained from an Indian mound
near Tessentee Creek, not far from the Littlefield mine, and hence pre-
sumably from that locality. This is the first instance recorded of a beryl
crystal found deposited in an Indian grave.
Another important locality in Macon County is the McG-ee mine. Here
the gems are sea-green and occasionally yellow, and are found in quantity.
A fine representation of the North Carolina beryl is to be seen in the
museum of the State University at Chapel Hill, together with the other
minerals of the State, collected by the late Mr. Stephenson, in the course
of his enthusiastic explorations, and whose cabinet was most appropriately
secured by the State.
HIDDENITE OR LITHIA EMERALD.
This is a stone which is peculiar to North Carolina, and hence possesses
especial interest in any account of the minerals of that State. The
circumstances under which it first came into notice have already been
mentioned under Emerald, with which it was found, at Stony Point,
Alexander County, in about 1879. Mineralogically, it is a variety of
spodumene, a well-known silicate of alumina and lithia, usually found in
large rather coarse crystals, opaque and of no beauty. Occasionally, how-
ever, it is transparent and richly colored (PI. III). The first occurrence
of this form of it in the United States, was in these small brilliant, green
crystals in North Carolina; a second has lately attracted much attention
in San Diego County, California, where the crystals are large and of a
rose-lilac tint ; this variety is the new gem-stone called kunzite.
The history of the North Carolina discovery is as follows :
About 1879, some crystals of a yellow and yellowish-green mineral,
7 Report Dept. Mining, Charleston Exposition, 1901.
46 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
supposed to be diopside, were found at Stony Point, Alexander County,
N. C, associated with beryl, quartz, rutile, garnet, dolomite, etc. These
crystals soon came into the hands of J. A. D. Stephenson of Statesville,
Who sent the best of them to Norman Spang, of Pittsburg, Pa., a noted
collector of choice minerals. About 2 years later Mr. Stephenson called
the attention of William E. Hidden to this mineral, and to the locality;
Mr. Hidden then sent specimens for examination to Dr. J. Lawrence
Smith, of Louisville, Ky., who found, on investigation, that the mineral
was not diopside but a transparent variety of spodumene. The crystals
were first found loose in the soil with emeralds, but systematic mining
revealed them attached to the veins of the wall-rock (PL XII, A). The
spodumene is generally more or less altered, hence its pitted or eaten-out
appearance ; but when found in the rock, the crystals are quite perfect and
unchanged. They are all transparent and range from colorless (rare),
to a light yellow, into yellowish-green, then into deep yellow emerald-
green. Sometimes an entire crystal has a uniform green color, but
generally one end is yellow and the other green. Its hardness is on
the prism faces, 6.5, and across them, according to Doctor Smith, nearly
that of the emerald ; but a series of experiments proved it to be some-
what less. At first considerable difficulty was experienced in cutting it,
owing to its remarkably perfect prismatic cleavage, which is very lustrous.
Gems have, however, been cut up to 2 -J carats in weight. Specific gravity,
3.18 to 3.194.
Specimens of the crystals and of cut stones, have gone into all important
public and private collections in the United States, and to some extent
abroad. Dr. Spencer, of the British Museum, has recently described
several specimens there contained, in a report to the Director, Dr.
Fletcher, as follows:
Hiddenite: Alexander County, N. C.
A faceted stone of a rich emerald-green color, perfectly transparent, and
with only 1 or 2 small cracks. Weight, 0.494 gram.
A piece of matrix bearing 2 or 3 small crystals. Also numerous isolated
prismatic crystals up to 2V2 centimeters in length; many rather pale in color,
but 3 crystals, presented by Mr. Hidden, in 1893, of a rich emerald-green.
The yellow tinge exhibited by this mineral in even the darkest green
gems will prevent it from competing with the emerald, since it is this
very quality that has kept down the prices of the Siberian demantoids,
or Uralian emeralds, as the green garnets are variously termed. The
finest crystal of lithia emerald ever found is in the Morgan-Bement
collection at New York. (See PI. III.) It measures 2f inches (68
BERYL GEMS AND SPODUMENE (HIDDENITE). 47
millimeters) by J inch (14 millimeters) by i inch (8 milli-
meters). One end is of very fine color, and would afford the largest gem
yet cut from this mineral, weighing perhaps 5J carats. In Dr. Augustus
C. Hamlin's cabinet is a fine gem weighing about 2 carats; and a cut
stone of fine color, and a good crystal are in the collection of Col. W. A.
Eoebling. Dr. J. Lawrence Smith 8 says that the crystals, when cut and
polished, resemble the emerald in luster though the color is not so intense
as in the finer varieties of the latter gem. Prof. Edward S. Dana says
that, owing to its dichroism, it has a peculiar brilliancy which is wanting
in the true emerald. Thomas T. Bouve, of Boston, says : " One might
infer from the statement .made of the great brilliancy of both the hiddenite
and garnet, when compared with the emerald, that this should decide
their relative beauty; but it is not the case, for the emerald has a beauty
of its own, in its deep and rich shade of color, that will ever make it rank
at least an equal in loveliness with the newer aspirants for favor." l
When the hiddenite was first introduced, it had a considerable sale because
of its novelty as an American gem and because of the newspaper notoriety
it gained through the controversy that arose as to its discovery. Hence
for a time the demand exceeded the supply, which, from the desultory
working of the mine, was limited. Thus a 2-J carat stone was sold for
$500.00, and a number of stones brought from $40.00 to over $100.00 a
carat. The total sale of all the gems found, from the beginning of oper-
ations in August, 1880, to the close of 1888, amounted to about $7500.00,
the yield in 1882, during which the preparatory work was done, being
about $2000.00. At the time of the discovery, this was supposed to be
the first occurrence of transparent spodumene; but Pisani, in the Comptes
Eendus for 1877, announced a transparent yellow spodumene that had
been found at Minas G-eraes, Brazil, where it exists in large quantities
and has been extensively sold as chrysoberyl. The writer saw nearly a ton
of broken crystals of this mineral at Idar, Germany, in 1881, whither it
had been sent for cutting. A stone from Brazil weighing 1 carat is
in the United States National Museum., as also a series of crystals and
cut stones from North Carolina. At Branchville, Conn., spodumene is
found in opaque crystals 4 or 5 feet long and a foot in diameter, almost
entirely altered to other minerals. In spots, however, it is transparent
enough to furnish small gems of an amethystine color. The alterations
which have taken place have entirely changed it to what might almost be
called a defunct gem; otherwise, these crystals would have afforded gems
8 Am. Jour. Sci., Ill, Vol. XXI, p. 128, Feb., 1881.
8Proc. Boston Soc. Nat. His., Vol. XXIII, p. 2, Jan. 2, 1884.
5
48 HISTORY OF THE GEMS FOUND IN NOPcTH CAROLINA.
over an inch in thickness and several inches in length. The color before
the alteration was probably much richer pink. It is of mineralogical
value only.
Within the past year, the discoveries in San Diego County, California,
have brought to light spodumene of "a similar color with the little rem-
nants at Branchville, but entirely clear and unaltered.
The North Carolina mineral was given its name by Dr. J. Lawrence
Smith (who first determined its true character) in honor of Mr. W. E.
Hidden. The crystals are slightly inclined prisms in form, ranging from
quite small up to perhaps 2 inches in length and from -J to \ of an inch
in diameter, for the largest. The first crystal of any size that was found,
was shown in the remarkable North Carolina gem-exhibit at the Charles-
ton Exposition of 1901-02. Notwithstanding the interest which attaches
to this peculiar and beautiful American gem, no further developments of
it have been made for several years, owing to the mines at Stony Point
being closed under litigation.
The chemical composition of hiddenite is given in the following table
of analyses :
Analyses of Hiddenite.
Specific Gravity, 3.152-3.189.
Constituent.
Silica
Alumina
P*er cent.1
63.95
26.58
Per cent
64.35
28.10
Ferric Oxide
0.25
Chromic Oxide
Ferrous Oxide
0.18
1.11
Lithia
Soda
6.82
1.54
7.05
0.50
Potassa
0.07
Water
0.15
1 F. A. Genth, analyst. Am. Jour. Sci.. Ill, 23. 68.
2 ,T. Lawrence Smith, analyst, Am. .Tour. Sci., Ill, 21, 128.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE XII
A. SPODUMENE (HIDDENITE) IN MATRIX, NATURAL SIZE, STONY POINT, N. C.
3. CYANITE, NATURAL SIZE, BURXSVILLE, N. C.
CHAPTER VII.
GARNET, ZIRCON, RUTILE, AND OCTAHEDRITE.
GARNET.
The name garnet is applied not to any single mineral, but to a well-
marked little group, comprising several species and varieties, differing
in color and chemical composition, but very closely related physically.
They all crystallize in the isometric system, and are all constructed on the
same type chemically, though varying considerably in their components.
They are silicates of lime, magnesium, iron, or manganese, with more or
less of alumina, ferric iron or chromium. According to the presence and
the proportions of these substances, the species and varieties are deter-
mined. Several members of the garnet group are found in North
Carolina, some of the commoner kinds in large quantities, so that they
have been mined for use as an abrasive and some of choicer quality that
yield beautiful gems.
Of the latter are to be noted the following: Almandine or precious
garnet, the iron-alumina variety; pyrope or Bohemian garnet, the mag-
nesia-alumina variety; rhodolite, a peculiar and beautiful garnet inter-
mediate between these two ; and spessartite, or manganese-alumina garnet.
This last is rare and the only North Carolina occurrence of it is reported
by Dr. J. H. Pratt, in beautiful flattened plate-like crystals in mica, near
Bakersville, some large enough to cut gems of a carat or more.1 Very
elegant crystals of large size have been found at Amelia Court House,
Virginia, in an albite pegmatite. This variety is not red, but of a peculiar
rich brown or fulvous tint (PI. XIII).
Almandite is the most frequent variety, and the one that has been mined
for garnet paper and other abrasive purposes, including a so-called
" emery," for which tons of it have been crushed. The color is red, of
many shades, varying to brownish and purplish reds. The peculiar play
of color observed in some of the North Carolina garnets is usually due
to inclusions. In Burke, Caldwell, and Catawba counties are found
large dodecahedral and trapezohedral almandite crystals coated externally
with a brown crust of limonite, the result of superficial alteration, but
1 Gems and Precious Stones of North America, New York, 1S00. pp. 70-S.'?.
50 HISTORY OF THE GEMS FOUND IN" NORTH CAROLINA.
usually showing a bright and compact interior when broken. They are
sometimes as fine in color as the Bohemian garnets, and should find a
ready use for watch-jewels and other like purposes. Some crystals have
been found weighing 20 pounds each. Although not fine enough for
gems, these might be cut into dishes or cups measuring from 3 to 6
inches across, as has been done in India. A very large quantity of these
garnets has been found about 8 miles southeast of Morganton, and also
near Warlick, in Burke County. Here they have been extensively mined
for abrasive use and also near HalFs Station in Jackson County, where
garnet wheels are manufactured.
Bohemian or pyrope garnets. — This garnet of good color, that has fur-
nished gems, has been found in the sands of the gold-washings of Burke,
McDowell, and Alexander counties. This species has a more blood red
N
tint than the preceding, and is used largely in the garnet jewelry made
in Bohemia, whence the name; it is the same also that passes under the
name of Cape ruby, from South Africa, and Arizona ruby, from the
territory of that name.
Rhodolite. — This is by far the most important variety of garnet in
North Carolina, and is found nowhere else, indeed, so that it possesses
peculiar interest. Since it has been recognized and developed, it has
proved to be also the most valuable gem produced commercially in the
State. The locality is much the same as that of the Cowee rubies, in
Macon County, in the gravels of streams heading on Mason;s Mountain,
and on the mountain itself at some points. When first observed it was
regarded as a very beautiful and brilliant light-colored form of almandine ;
but analysis subsequently showed that it is a variety intermediate between
that and pyrope, in fact an inter-mixture of the two, in the proportion of
f pyrope and -J almandine.
The first mention of these Macon County garnets was apparently due
to Mr. A. M. Field, of Asheville, in 1893,2 and was made by the author
in his report on the production of precious stones for that year, and
again in 1897.3 In the following year, a paper was published by Mr. W.
E. Hidden and Dr. J. H. Pratt, in which the whole subject was treated
fully, the analyses described, the nature of the stone determined, and the
name of rhodolite proposed for it as a new variety.4 This name is from
the Greek word rhodon, a rose, from the resemblance of its color to some
kind of roses and rhododendrons. The mineral shows a light shade of
fine red, without the dark aspect that belongs to most garnets, and it
2Min. Res. U. S., 1893 (Rep. U. S. Geol. Survey), pp. 15 and 19.
3Min. Res. TJ. S., 1897 (Rep. U. S. Geol. Survey), p. 13.
4 Am. Jour. Sci., IV, Vol. V, 1898, pp. 293-296 ; and also Vol. VI, pp. 463-46S.
Plate No
B
Cyan ile,
Seven .Mile Ridge, Mitchell County,
North Carolina.
A
Cyan He,
Seven Mile Ridge, Mitchell County,
North Carolina.
©
c
Rhodolite.
Cowee Valley,
Macon Couniv. North Carolina,
D
Rhodolite.
<v Valley,
Macor. Couniv. North
i hvl'almi PrrtnoArt Cc
• ■ d
II
GARNET, ZIRCON, RUTILE, AND OCTAIIEDRITE. 51
a
possesses a remarkable degree of brilliancy, especially in artificial light.
Those qualities give it great value for gem purposes, and it has become
very popular. The pieces found are not generally large, but stones have
been cut of as much as 14 carats. A very fine exhibit of rhodolites was
made in the State Geological Survey Exhibit at the recent Expositions at
Buffalo, Charleston, and St. Louis. They have been developed by two
companies with remarkable success; and apparently more gems in value
have been sold from this mine than from all other sources in the State
combined. (See PL XIII.)
Perhaps $53,000 worth of these stones have been sold from these
mines to date.
ZIRCON.
Zircon (silicate of zirconia) is a mineral of somewhat wide distribu-
tion, though rarely conspicuous. It crystallizes in square prisms with
pyramidal terminations, generally opaque and of some shade of brown.
When transparent, and of any size, beautiful gems can be cut from
zircon crystals ; these are the hyacinths of jewelers.
In North Carolina zircon is abundant in the gold sands of Polk, Burke,
McDowell, Eutherford, a'nd Caldwell counties, and in nearly all the
colors found in Ceylon — yellowish-brown, brownish- white, amethystine,
pink, and blue. The crystals are beautifully modified, but too minute
to be of value. Brown and brownish-yellow crystals, very perfect in form,
occur abundantly in Henderson County, N. C, and in equal abundance
in Anderson County, S. C. The latter are readily distinguished from the
North Carolina crystals, as they are generally larger, often an inch across,
and the prism is almost always very small, the crystal frequently being-
made up of the two pyramids only. They are found in large quantities,
loose in the soil, as the result of the decomposition of a feldspathic rock.
Large and richly colored zircons, sometimes as much as 2 ounces in
weight, and of fine shades of brown and hone}^-red, are found in Iredell
County.5.
Within the past 20 years some demand has arisen and continued for
minerals containing the rare earths, — zirconia, thoria, etc., — as these
substances are used for the mantles or hoods of the Welsbach and other
forms of incandescent gas burners. This demand led to active search
throughout the world for the minerals containing these oxides, and so
successful has been this search that many species which were once con-
sidered rare are now so plentiful that they are quoted at one-tenth to one-
5 N. C. Geolog. Survey, Economic Paper, No. 6, 1901, p. 99; and Department of
Mining Statistics, 1898, p. 34.
52 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
hundredth of their former prices. The best zircon localities in Xorth
Carolina are on the Old Meredith Freeman estate, and the Jones estate,
Green Kiver, Henderson County. It was leased for 25 years by Gen.
Thomas L. Clingman, who, as early as 1869, mined 1000 pounds of zircon,
and during that whole period never lost faith in the incandescent proper-
ties of zirconia; but when these were finally proved and acknowledged,
through some legal difficulties General Clingman had forfeited his leases,
and hence failed to reap his reward. The zircon industry has been quite
important in North Carolina; and as far back as 1883 Mr. W. E. Hidden
mined 26 tons in that single year. The chemical composition of zircon
is shown below in the analysis of a sample of this mineral from Buncombe
County.
Analysis 6 of Zircon from Buncombe County, N. C.
Specific Gravity, 4.607.
Constituent. Per cent. T^° ^al
Silica -33.70 32.80
Zirconia 65.30 67.20
Ferric Oxide 0.67
Water 0.41
RUTILE.
This is one of the most interesting minerals found in North Carolina,
although not one that is very conspicuous. In composition, it is pure
oxide of the metal titanium, and varies in color from deep red or reddish-
brown to black, the crystals being modified square prisms. Specimens
from Alexander County rival any that have ever been found for their
perfection of form, wonderful polish, and fine color (PL XIV, A and B,
and PI. XV). At Graves Mountain, Georgia, elegant rutile occurs with
lazulite usually imbedded in a compact red oxide of iron that can be
readily removed by hydrochloric acid, or with a sharp instrument, leaving
on the surfaces a mirror-like polish. The crystals vary in length from -J
an inch up to 5 inches, and are either single, twins, or vieriings, often
in fine groups. The rutile from this locality has realized at least $20,000
for cabinet specimens, and has supplied the collections of the world
through the perseverance of Prof. Charles IT. Shepard. It occurs in a
similar association with lazulite in North Carolina, at Crowders Mountain,
in Gaston County.
The finest small brilliant geniculated crystals are found at Millholland's
Mills, White Plains, near Liberty Church, and near Poplar Springs, in
r;C. F. Chandler, analyst, Am. Jour. Sci., II, 24, 131.
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE XIV
1
1
>
o
r
*-*
Z
>
A. RUTILE CRYSTALS, NATURAL SIZE, STONY POINT, N. C.
B. RUTILE, RETICULATED, NATURAL SIZE, NEAR HIDDEN1TE P. 0., ALEXANDER COUNTY. N. C.
GARNET, ZIRCON, RUTILE AND OCTAIIEDRITE. 53
Alexander County, see Plate XIV. These have furnished some of the
finest cut black rutile, which more closely approaches the black diamond
in appearance than any other gem. Some of the lighter colored ones
furnish gems strongly resembling common garnet. Beautiful long crys-
tals at times transparent red, ranging from the thickness of a hair to J
and in some instances § inch across, and from 1 inch to 6 inches in length,
often doubly terminated and very brilliant, have been found at Taylors-
ville, Stony Point, and elsewhere in that vicinity. A very marked form
of rutile is that in which these slender red crystals penetrate transparent
quartz, both colorless and smoky, forming the beautiful combination
called sagenite, or by the French, " fleches d'amour" (love's arrows)
(PL V). This material is found of remarkably fine quality at several
points in North Carolina, and is described in this report under Quartz
Inclusions.
Dr. Joseph Hyde Pratt has recently reported the occurrence of beau-
tifully terminated rutile crystals from near Mebane, Orange County. The
crystals are up to 1J inches long and J broad and are imbedded in
pyrophyllite.
OCTAHEDRITE.
Octdhedrite is a rare mineral, identical with rutile in composition, but
entirely different in the form of its crystals. It is described by W. E.
Hidden 7 as occurring in thin tabular, glassy crystals of a pale-green color
and very brilliant up to J of an inch in diameter, in the gold sands of
Brindletown Creek and elsewhere in Burke and the adjoining counties,
especially on the northern slope of Pilot Mountain. These might afford
small gems that would compare favorably with the beautiful blue crystals
from Brazil, which are so brilliant as to have been mistaken for diamonds.
Cassiterite, the oxide of tin, has been found in considerable quantities at
King's Mountain. Fine specimens may be cut like rutile, but this
place has not yielded a single gem, or been worked as yet with commercial
success for tin.
7 Am. Jour. Sci., Ill, Vol. XXII, July, 1881, p. 26.
CHAPTER VIII.
CYANITE, EPIDOTE, TOURMALINE, CHRYSOLITE (PERI-
DOT), SERPENTINE, SMARAGDITE, LAZUL1TE,
MALACHITE, AND PEARLS.
CYANITE.
This mineral (also spelled kyanite) is a subsilicate of alumina almost
identical in composition with andalusite, and very closely related also to
topaz. It is named from the Creek huanos, blue, in allusion to its pre-
vailing color, and was also called by old writers sappar, from a corruption
of sapphire, which the fine clear cyanites of deep tint sometimes resemble.
It occurs generally in long prismatic or blade-like crystals, and is not
uncommon in the gneissic rocks of New England and Southeastern
Pennsylvania to North Carolina (Pis. XIII and XII, B). It presents
various shades of blue and blue-green, occasionally varying to pure white,
— the variety from the Tyrol called rhcetizite. Fine crystals occur with
lazuli te at Chibb's and Crowder's mountains, on the road to Coopers
Gap, in Gaston County, and also in Rutherford County. Cyanite is some-
what frequently associated with corundum, from which Dr. Genth believed
it to be derived by alteration. Another locality is at Swannanoa Gap,
in Buncombe County; but the finest specimens are found in Mitchell
County,1 where it occurs in distinct isolated crystals that, for perfection.
depth of color, and transparency, rival those from St. Gothard,
Switzerland. The locality is at an altitude of 5500 feet, near the summit
of Yellow Mountain on the road to Marion, 4 miles southeast of Bakers-
ville, in a vein of white massive quartz in a granitic bluff, associated with
almandite garnet of a very light transparent pinkish-purple color. The
vein has a dip of 60 degrees, bearing northeast and southwest. The color
varies from almost colorless to deep azure-blue, as dark as the Ce}Tlonese
sapphire, also occasionally green. Some of the crystals are 2 inches long,
while a few were observed f inch (15 millimeters) in width and f inch
(10 millimeters) in thickness. Occurring in white quartz, they form
beautiful specimens, and the loose crystals were extensively sold for
sapphire some years ago, at Roan Mountain, the summer resort. A few
'Am. Jour. Sci.. III. Vol. XXXVI. p. 224. Sept., 1888.
CYANITE, EPIDOTE, TOURMALINE, SMARAGDITE, ETC. 55
gems have been cut, and a fine example is in the United States National
Museum. It is, however, too soft to admit of much wear.
Another locality of fine cyanite in the same vicinity, was described in
1898 by Dr. J. H. Pratt.2 This was on the farm of Mr. T. Young, in
Yancey County, on North Toe Eiver, a few miles from Spruce Pine,
Mitchell County. Here the cyanite is frequently of a rich mossy green
color, sometimes perfectly transparent; and some of the crystals are blue
along the center with grass-green margins. Many of them are terminated,
which is not common in cyanite; and the locality seems a very promising
one.
EPIDOTE.
Prof. Frederick A. Genth mentions 3 a crystal of epidote in the cabinet
of the University of Pennsylvania, from the gold-washings of Eutherford
County, N. C. This crystal is strongly pleochroic, like the so-called pusch-
kinite from the auriferous sands of Ekaterinburg, in the Ural Mountains,
and would cut into a small gem. Some fine highly complex forms have
been observed at Hampton's, Yancey County, by William E. Hidden.
These crystals might possibly afford cabinet gems, not equal, however,
to the Tyrolese epidote. Handsome prismatic crystals, 1-J inches in length
and i in diameter, have been reported by Mr. 0. H. Blocher, of Old Fort,
McDowell County, as found some 40 miles from that place, but with no
more specific location. They are brilliant, but of too dark a green to
have much promise as gems.
Crocidolite was observed by Joseph Wilcox in long, delicate fibers of a
blue color, in one of the western counties of North Carolina.
TOURMALINE.
This is a complex boro-silicate of alumina and several oxides, which is
frequent in various crystalline rocks, and in its common black form is
found at numerous North Carolina localities. But the richly colored
varieties which are valued as gem stones, and are found in Maine, Con-
necticut, and Southern California, do not appear in North Carolina.
The only announcement of the presence of any of them, thus far, was
made several years ago by Messrs. D. C. Morgan and Company, of Waynes-
ville, Haywood County, who reported crystals of transparent green
tourmaline as found near that place. The colored tourmalines usually
contain some lithia, and are nearly always found, when they do occur, in
pegmatite dikes. As these latter are frequent in the western counties,
. 2Am. Jour. Sci., IV, Feb., 1898, pp. 126, 127.
3 Minerals and Mineral Localities of North Carolina, Raleigh, p. 44, 1881.
56 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
it seems remarkable that almost no tourmalines of this kind have been
found in all the mining and prospecting work.
CHRYSOLITE (OLIVINE, PERIDOT ).
This mineral is a silicate of magnesia and iron. It occurs largely in
an altered form in North Carolina, as the leading constituent of the
decomposed peridotites called dunites, but very rarely in its unchanged
condition. It is a green to yellow mineral, nearly as hard as quartz
(6.5-7), and when transparent and in pieces of any size, it is valued
as a brilliant gem-stone, — the chrysolite or peridot of jewelers. Xear
Webster, in Jackson County, it is found in granular masses, of a bright
yellow-green color, and susceptible of a fine high polish. This material.
if present in any quantity, might be utilized as a pleasing ornamental
stone; but not as a gem, unless more transparent and in larger pieces.
Analyses of Chrysolite from Wedster, Jackson County N. C.
Constituent. Percent.4 Percent.5 Percent.0
Silica 41.89 40.74 41.17
Ferric Oxide ) n co 1 00
- U.Oo l.oo
Chromic Oxide )
Ferrous Oxide 7.39 7.26 7.35
Nickel Oxide 0.35 0.39 0.41
Lime 0.06 0.02 0.04
Magnesia 49.13 49.18 49.16
4 F. A. Genth, analyst, Am. Jour. Sci., Ill, 33, 200.
51. c.
eF. A. Genth, analyst, Am. Jour. Sci., II, 33, 199.
4 Color, pale grayish green.
5 and 6 Color, yellowish olive green.
SERPENTINE.
This mineral, a hydrous silicate of magnesia, occurs widely distributed
throughout some portions of the State, and is often a result of the alter-
ation of the olivine-bearing rocks (peridotite, dunite) already repeatedly
mentioned. At some points it is massive and of good color and quality,
such as might be used for building-stone, as it is frequently near Phila-
delphia. But the translucent and rich green variety known as precious
serpentine, which is used as an ornamental stone like that of Maryland,
has been recognized only at a few points and does not appear as yet to
have been utilized at all. Dr. Pratt mentions several promising outcrops
in Buncombe County, between Leicester and Weaversville. and others in
Madison and Yancey counties. Still another, where the serpentine is of
fine quality, is in Wilkes County, where it forms the rock of the asbestos
N. C. GEOLOGICAL AND ECONOMIC SURVEY
BULLETIN NO. 12. PLATE XV
CYANTTE, EPIDOTE, TOUKMALINE, SMARAGDITE, ETC. 57
mine near North Wilkesboro. It is hard and compact and polishes hand-
somely, and might prove as beautiful as that of Harford County, Mary-
land. Dr. Genth, also, years ago, stated that a serpentine from the
neighborhood of Patterson, Caldwell County, of a dark greenish-black
color, admits of a fine polish.7
Analysis 8 of Serpentine, Webster, N. G.
Constituent. Per cent.
Silica 43.87
Alumina 0.31
Ferrous Oxide 7.17
Nickel Oxide 0.27
Magnesia 38.62
Water 9.55
EDENITE ( SMARAGDITE. )
Smaragdite is a variety of hornblende (amphibole), which occurs
plentifully at the Cullakenee Corundum Mine, Clay County, N. C. In
color it is bright emerald to grass-green, also grayish and greenish-gray.
Masses through which the pink and ruby corundum occur disseminated,
are exceedingly beautiful. The mineral is hard enough to admit of a fine
polish and is worthy of attention as an ornamental or decorative stone.
It has recently been utilized for such purposes, under the name of " ruby
matrix." Pieces are selected in which bright portions of red or pink
corundum are enclosed in the rich green smaragdite, and the contrast
makes a very attractive material. Smaragdite occurs also near Elf, on
Shooting Creek, in the same county, similarly associated with corundum,
pink and dark blue.
LAZULITE.
Lazulite is a somewhat rare mineral, a phosphate of alumina containing
some magnesia and protoxide of iron. It occurs in pale and dark blue
crystals and crystalline masses at Clubb Mountain and Crowder's Moun-
tain, in Gaston County, and at Sauratown, in Stokes County. The finest
crystals, however, come from Graves' Mountain, Georgia, some of the m
being as much as two inches in length. Its hardness is 6, and its specific
gravity is 3.122. This mineral would make an opaque gem or an orna-
mental stone, as the color, though lighter, is often as rich as that of lapis
lazuli, for which it was mistaken when first found.
7 Mineral of N. C, p. 57.
8F. A. Genth, analyst, Am. Jour. Sci., II. 33. 201.
58 HISTORY OF THE GEMS FOUND IN NORTH CAROLINA.
Analysis 9 of Blue Lazulite from Gaston County, N. C.
Constituent. Per cent. Per cent.
Phosphoric Acid 43.38 44.15
Alumina 31.22 32.17
Ferrous Oxide 8.29 8.05
Magnesia 10.06 10.02
Silica 1.07 1.07
Water 5.68 5.50
Hardness 5.0-6.0 5.0-6.0
MALACHITE.
This beautiful green carbonate of copper, often used as an ornamental
stone as well as mined for an ore of the metal, is found somewhat in
Guilford, Cabarrus, and Mecklenburg counties. The fibrous variety has
been observed at Silver Hill and at Conrad Hill, in Davidson Count}7, and
in a number of other localities in North Carolina, but is rarely of any gem
value. In the Torrey Collection at the United States Assay Office, in
New York City, are a few fine gem pieces of malachite from the Copper
Knob mine in Ashe County.
PEARLS.
The Indians of Carolina, Georgia, Florida and Alabama, gathered
mussels and conchs, as shown by the numerous refuse piles and shell
heaps that abound upon the salt-water creeks. It is not a matter of
surprise that the Indians, as they opened these shells, should have care-
fully watched for pearls, and from the vast numbers examined, should
have accumulated a store. If the shores of Carolina, Georgia, and
Florida did not afford the larger and more highly prized pearls, it is
not impossible that pearls from the islands and lower portions of the
Gulf of Mexico, and even from the Pacific coast, may have found their
way into the heart of Georgia and Florida and into more northern
localities, to be there bartered away for skins and other articles. The
replies of Indians to Father Hennepin and others and the presence in
remote localities of beads, ornaments, and drinking-cups made of marine
shells and conchs, still peculiar to the Gulf of Mexico, confirm the
truthfulness of this suggestion.10
9 Analysts, Smith & Brush. Dana, Mineralogy, 5th ed., p. 572.
10 Ancient Aboriginal Trade in North America, by Charles Rau. Report of the
Smithsonian Institution for 1872, Washington, 1873 ; Gems and Precious Stones of
North America, New York, 1890-92 ; TJ. S. Commission Fish and Fisheries, 1S93-9S ;
Pearls, by Geo. F. Kunz, Charles H. Stevenson, Century Co., New York, 1907.
I
PUBLICATIONS
OF THE
NORTH CAROLINA GEOLOGICAL AND ECONOMIC SURVEY.
BULLETINS.
1. Iron Ores of North Carolina, by Henry B. C. Nitze, 1893. 8°, 239 pp., 20
pi., and map. Postage 10 cents.
2. Building and Ornamental Stones in North Carolina, by T. L. Watson and
F. B. Laney in collaboration with George P. Merrill, 1906. 8°, 283 pp., 32 pi.,
2 figs. Postage 25 cents. Cloth-bound copy 50 cents extra.
3. Gold Deposits in North Carolina, by Henry B. C. Nitze and George B.
Hanna, 1896. 8°, 196 pp., 14 pi., and map. Out of print.
4. Road Material and Road Construction in North Carolina, by J. A. Holmes
and William Cain, 1893. 8°, 88 pp. Out of print.
5. The Forests, Forest Lands and Forest Products of Eastern North Caro-
lina, by W. W. Ashe, 1894. 8°, 128 pp., 5 pi. Postage 5 cents.
6. The Timber Trees of North Carolina, by Gifford Pinchot and W. W. Ashe,
1897. 8°, 227 pp., 22 pi. Postage 10 cents.
7. Forest Fires: Their Destructive Work, Causes and Prevention, by W. W.
Ashe, 1895. 8°, 66 pp., 1 pi. Postage 5 cents.
8. Water-powers in North Carolina, by George F. Swain, Joseph A. Holmes
and E. W. Myers, 1899. 8°, 362 pp., 16 pi. Postage 16 cents.
9. Monazite and Monazite Deposits in North Carolina, by Henry B. C. Nitze,
1895. 8°, 47 pp., 5 pi. Postage h cents.
10. Gold Mining in North Carolina and other Appalachian States, by Henry
B. C. Nitze and A. J. Wilkins, 1897. 8°, 164 pp., 10 pi. Postage 10 cents.
11. Corundum and the Basic Magnesian Rocks of Western North Carolina,
by J. Volney Lewis, 1895. 8°, 107 pp., 6 pi. Postage 4 cents.
12. History of the Gems found in North Carolina, by George Frederick
Kunz, 1907. 8°, 60 pp., 15 pi. Postage 6 cents.
13. Clay Deposits and Clay Industries in North Carolina, by Heinrich Reis,
1897. 8°, 157 pp., 12 pi. Postage 10 cents.
14. The Cultivation of the Diamond-back Terrapin, by R. E. Coker, 1906.
8°, 67 pp., 23 pi., 2 figs. Postage 6 cents.
15. Experiments in Oyster Cultutre in Pamlico Sound, by Robert E. Coker.
In press.
16. A List of Elevations in North Carolina, by Joseph Hyde Pratt and
E. W. Myers. In preparation.
17. The Loblolly Pine in Eastern North Carolina, by W. W. Ashe. In prepa-
ration.
18. Shade Trees in North Carolina, by W. W. Ashe. In preparation.
19. The Tin Deposits of the Carolinas, by Joseph Hyde Pratt and Douglass
B. Sterrett, 1905. 8°, 64 pp., 8 figs. Postage J, cents.
ECONOMIC PAPERS.
1. The Maple-Sugar Industry in Western North Carolina, by W. W. Ashe,
1897. 8°, 34 pp. Postage 2 cents.
60 LIST OF PUBLICATION'S.
2. Recent Road Legislation in North Carolina, by J. A. Holmes. Out of
print.
3. Talc and Pyrophyllite Deposits in North Carolina, by Joseph Hyde Pratt,
1900. 8°, 29 pp., 2 maps. Postage 2 cents.
4. The Mining Industry in North Carolina During 1900, by Joseph Hyde
Pratt, 1901. 8°, 36 pp., and map. Postage 2 cents.
5. Road Laws of North Carolina, by J. A. Holmes. Out of print.
6. The Mining Industry in North Carolina During 1901, by Joseph Hyde
Pratt, 1902. 8°, 102 pp. Postage 4 cents.
7. Mining Industry in North Carolina During 1902, by Joseph Hyde Pratt,
1903. 8°, 27 pp. Postage 2 cents.
8. The Mining Industry in North Carolina During 1903, by Joseph Hyde
Pratt, 1904. 8°, 74 pp. Postage 4 cents.
9. The Mining Industry in North Carolina During 1904, by Joseph Hyde
Pratt, 1905. 8°, 95 pp. Postage J, cents.
10. Oyster Culture in North Carolina, by Robert E. Coker, 1905. 8°, 39 pp.
Postage 2 cents.
11. The Mining Industry in North Carolina During 1905, by Joseph Hyde
Pratt, 1906. 8°, 95 pp. Postage 4 cents.
12. Investigations Relative to the Shad Fisheries of North Carolina, by John
N. Cobb, 1906. 8°, 74 pp., 8 maps. Postage 6 cents.
13. Report of Committee on Fisheries in North Carolina. Compiled by
Joseph Hyde Pratt, 1906. 8°, 78 pp. Postage 4 cents.
14. Mining Industry of North Carolina during 1906, by Joseph Hyde Pratt,
A. A. Steel, and Douglas B. Sterrett. In press.
VOLUMES.
Vol. I. Corundum and the Basic Magnesian Rocks in Western North Caro-
lina, by Joseph Hyde Pratt and J. Volney Lewis, 1905. 8°, 464 pp., 44 pi.,
35 figs. Postage 32 cents. Cloth-bound copy 50 cents extra.
Vol. II. The Fish of North Carolina, by H. M. Smith. In press.
Vol. III. Miscellaneous Mineral Resources in North Carolina, by Joseph
Hyde Pratt. In preparation.
y Vol. IV. Mica Deposits of Western North Carolina, by Joseph Hyde Pratt
and Douglas B. Sterrett. In preparation.
Samples of any mineral found in the State may be sent to the office of the
Geological and Economic Survey for identification, and the same will be
classified free of charge. It must be understood, however, that xo assays, or
quantitative detekminations, will be made. Samples should be in a lump
form if possible, and marked plainly with name of sender outside of package,
post-office address, etc.; a letter should accompany sample and stamp should
be enclosed for reply.
These publications are mailed to libraries and to individuals who may de-
sire information on any of the special subjects named, free of charge, except
that in each case applicants for the reports should forward the amount of
postage needed, as indicated above, for mailing the bulletins desired, to the
tttate Geologist, Chapel Hill, N. C.
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NORTH CAROLINA GEOLOGICAL SURVEY
J. A. HOLMES, STATE GEOLOGIST
BULLETIN No. 13
CLAY DEPOSITS AND CLAY INDUSTRY
IN NORTH CAROLINA
A PRELIMINARY REPORT
HEINRICH RIES
RALEIGH
Guy V. Barnes, Public Printer
1897
Hf'lJL-
i
CONTENTS
PAGE
Illustrations 6
Letter of Transmittal 8
Preface 9
Chapter I. — The Origin of Clay 11
Chapter II. — Chemical properties of clay 15
Impurities in clay 15
Fluxing impurities . . 16
Alkalies in clay 1G
Soluble alkaline compounds 17
Insoluble alkaline compounds 17
Compounds of iron in clay 18
Lime in clay ; . . 20
Effect on the brick of calcium carbonate in clay 21
Magnesia in clays 23
Non-fluxing impurities , 23
Silica 24
Titanium 24
Organic matter 25
Water 26
Methods employed in making clay analyses 2T
The rational analysis of clay 30
Chapter III. — Physical properties of clay 33
Plasticity 33
Tensile strength 34
Shrinkage 35
Fusibility 36
Temperature at which clay fuses 37
Measurement of temperatures 3S
The thermo-electric pyrometer 38
Seger's pyramids :'»s
Slaking of clays 42
Minor physical properties of clays 42
Absorption of water 42
Texture 42
Taste 4:;
Color 4:;
Density 43
4 CONTENTS.
PAGE
Chapter IV. — Geology and geography of North Carolina clay deposits 44
Residual clays , 44
Sedimentary clays 46
The North Carolina clay working industry 48
Chapter V. — Kaolins or china clays 50
Character, Mining, Preparation for market 50
Distribution of the kaolins 50
Mineralogical character of kaolin 50
Properties of kaolin 51
Mining of kaolin 53
Preparation of kaolin for market 54
Deposits of kaolin in North Carolina 58
Kaolin in Jackson county 58
Macon county 62
Montgomery county 64
Richmond county 65
Uses of the North Carolina kaolins 68
Chapter VI. — Pottery Clays in North Carolina 71
The pottery industry 71
Requisites of a pottery clay 72
Stoneware manufacture 73
Pottery industry in Burke county 75
Catawba county 76
Lincoln county 77
Wilkes county 78
Chapter VII. — Fire-clays and pipe-cla}rs in North Carolina 80
Fire-clays SO
Fire-clays in Cleveland county 81
Guilford county S3
Pipe-clays in North Carolina S6
Manufacture of sewer pipes and tiles S6
Guilford county SS
Chapter VIII. — Brick-clays and brick manufacturing 92
General character of brick-clays 92
Requisites of brick-clays 93
Methods of brick manufacture 94
Soft-mud process 94
Stiff-mud process 96
Dry-press process 99
Chapter TX. — Brick-clay deposits in North Carolina 102
Brick-clays in Bladen county 102
Buncombe county 104
Burke county 107
Cleveland county 108
Cumberland county 110
Forsyth county Ill
Gaston county 113
CONTENTS. 5
PAGE
Chapter IX. — Continued.
Brick-clays in Guilford county 114
Halifax county , 116
Harnett county 119
Jackson county 121
Martin county 122
Mecklenburg county 122
Richmond county 125
Robeson county 126
Rowan county , 127
Surry county 128
Union county 129
Wake county 130
Wayne county 131
Wilkes county 134
Wilson county 136
Comparison of Wilson and Wayne county clays 138
Chapter X. — Manufacture of paving-brick 139
Requisite character of clay 139
Manufacture of paving-brick 140
Table of Chemical Analysis of Clays „ 142
Table of Physical Properties of Clays 146
Bibliography 150
Index 153
ILLUSTRATIONS.
PAGE
Plate I. Pomona Terra Cotta Works, Pomona, N. C Frontispiece.
II. Map showing distribution of geological formations in Xorth Carolina . . 44
III. Fig. 1, Kaolin washing and drying plant, Harris Clay Co 56
2, Harris Clay Co.'s mine, showing method of sinking pits in soft
kaolin 56
IV. Fig. 1, Wooden frame kaolin filter-press -. 58
2, Iron frame kaolin filter-press 58
V. Fig. 1, Residual kaolin deposit, Harris Clay Co.'s mine, near Webster.. . 59
2, Residual clay deposit, Powhatan Clay Mfg. Co., near Grover 59
VI. Fig. 1, Press for sewer-pipe, tile, and hollow brick 86
2, Chaser mill for tempering clay for sewer-pipe 86
VII. Fig. 1, Circular down-draft kiln for tile, etc 88
2, Tunnel dryers, used in brick making 88
VIII. Fig. 1, Stiff-mud auger end-cut brick machine ." . 98
2, Re-pressing brick machine 98
IX. Fig. 1, Interior view of a continuous brick-kiln 99
2, Exterior view of a continuous brick-kiln 99
X. Fig. 1, Up-draft brick-kilns, for burning common brick, at the State
Penitentiary, Raleigh, N. C 101
2, Down-draft brick-kiln. Eudaly type 101
XL Fig. 1, Black clay along Cape Fear river, at Prospect Hall 110
2, Poe Bros', clay bank, Fayetteville, N. C 110
XII. Fig. 1, Brick works of Carter and Shepard, Bethania 120
2, Clay deposit in railway cut, Spout Springs, C. F. & Y. V. railroad. 120
Fig. 1. Pump for removing kaolin from settling vats and forcing it into the presses. 57
2. Potter's jolly, No. 3 74
3. Vaughan sewer-pipe press S7
4. Dry-pan crusher 97
5. Dry-press brick machine 100
■
BOARD OF MANAGERS.
Govern ob. D. L. Russell, ex-officio Chairman, . . Raleigh.
Charles MoNamee, ....... Biltmore.
J. Turner Morehead, ...... Leaksville.
STATE GEOLOGIST.
J. A. Holmes, Chapel Hill.
LETTER OF TRANSMITTAL.
To His Excellency, Hon. D. L. Russell,
Governor of North Carolina
and Chairman of the Geological Board.
Sir: — I have the honor to transmit as bulletin 13 of the Survey series,
a preliminary report on some of the clay deposits and the clay industry
in North Carolina, by Dr. Heinrich Hies. This report is not intended
as a complete or final discussion of the clay deposits of this State. Their
examination has thus far been limited mainly to the regions about towns
and railway stations, where the need for information is greatest: but
during the next few years it is expected that this work will be ex-
tended to all portions of the State where there is a probability of dis-
covering workable deposits of clay or kaolin.
Meanwhile it is thought best to publish, in response to the calls for
immediate information, this preliminary report, which I regard as an
important contribution to our series of reports on North Carolina
resources. I believe it will be well received by the clay workers of the
State, and hope that it will prove useful to them.
Yours obediently,
J. A. Holmes,
State Geologist.
Raleigh, N. C,
July 15, 1897.
PREFACE
The following investigation of the North Carolina clays was under-
taken for the purpose of determining (1) the extent, qualities, appli-
cability of the clays occurring within the State; and (2) whether those
deposits now being utilized could be used for making other or better
products than those that are now being manufactured from them,
by varying the mixtures or by the use of different appliances in the
manufacture. The field work was earned on during the spring and
autumn of 1896, and many of the clay deposits (nearly 100) were
visited. Samples were collected from about seventy beds and sub-
mitted to chemical and physical investigation.
The chemical work was earned out in a careful and detailed manner
by Prof. Chas. Baskerville, of the University of North Carolina. In
each case the constituents determined were free and combined silica,
alumina, ferric oxide, lime, magnesia, alkalies, moisture, and water. In
certain cases determinations were also made of the ferrous oxide, organic
matter, sulphur, and titanic oxide. Of the high grade clays, such as the
kaolins, a rational analysis was made in each case. This, though of
great importance, has rarely been done in this country, although it is
often carried out abroad. From the rational analysis, as pointed out
in the report, it is possible to compute the percentage of clay substance,
quartz, and feldspar in the clay, a fact which is of great practical value
to the manufacturer, for it gives him an important guide in making up
the mixture for the body.
The physical investigations consisted in determining the amount of
water required to be added to give a workable mass, the shrinkage in
drying and burning of bricklets made from this mud; the color to which
the clay burns; the temperatures of incipient fusion, vitrification, and
viscosity; the cohesion or tensile strength of the air-dried clay, deter-
mined by making briquettes and pulling them apart in a cement testing
1 0 PREFACE.
machine; the texture of the clay; the slaking in water; and other minor
physical characteristics.
The fire tests were carried on in a regenerative gas furnace for tem-
peratures up to 2500 degrees F., but for temperatures above this a
Deville furnace was used.
The results of the work show that North Carolina contains an abun-
dance of kaolin of superior quality, as well as clays for the manufacture
of stoneware, pressed brick, sewer pipe, and probably paving brick if a
mixture of clays is used.
The presence of good clays for the better grades of structural mate-
rial is of itself a matter of importance, as at present nearly all such
wares are brought from other States at considerable cost. While the
sedimentary " bottom " clays yield smoother and usually better pro-
ducts than the residual ones, still experiments and practical tests show
that the product made from the latter is materially improved by the
proper manipulation.
Many of the products are easily accessible, being situated either along
navigable rivers or near the intersection of important lines of traffic.
As only a portion of the clay deposits has as yet been examined, this
must be regarded as a preliminary report. It is expected that these
investigations will be continued until the more promising clay deposits
in all parts of the State shall have been examined, and a final and more
elaborate report will then be prepared for publication.
Acknowledgments are due to the clay workers of the State for the
uniform courtesy with which they have aided the gathering of informa-
tion for this report.
The American Clay-working Machinery Co., of Bucyrus, O., The
Turner, Vaughn and Taylor Co., of Cuyahoga Tails, O., and the
Director of the New York State Museum have kindly loaned several
of the illustrations for this report.
ITeixkich TIies.
May 9, 181)7.
CLAY DEPOSITS AND CLAY INDUSTRY IN NORTH
CAROLINA.
By Heinrich Bjes, Ph. D.
CHAPTER I.
THE OEIGIJST OF CLAY.
Forming as it does one of the most abundant materials of the sur-
face of the earth's crust, the enormously extensive application of clay
is not to be wondered at. It is to be found almost everywhere, but
varies greatly in form, color, and other chemical and physical char-
acters. There are two properties, however, which are more or less con-
stant, and by means of which clay can be generally recognized. These
are plasticity when wet, so that any form can be given it by pressure;
and the retention of this form when air-dried.
Pure clay is composed of the mineral kaolinite, which is a hydrated
silicate of alumina, and masses of it are called kaolin. It rarely hap-
pens that kaolin is found in a strictly pure state, for more or less foreign
mineral matter is usually present, and may form such a large percentage
of the kaolin as to completely mask the kaolinite. The latter is known
as the clay substance, the foreign minerals being regarded as impurities.
Clay may therefore be defined as a mixture of kaolinite with more or
less quartz and other mineral fragments (hydrates, silicates, etc.) pos-
sessing usually plasticity when mixed with water, and when subjected
to a high heat becoming converted into a hard, rock-like mass.1
Kaolinite, the base of all clays, is not an original mineral of the
earth's crust, but a secondary one, resulting from the decomposition of
feldspars, and possibly sometimes from other aluminous mineral-. The
feldspars are a group of silicate minerals of rather complex composition,
but orthoclase (the common feldspar), which serves as the type of the
group, is a compound of silica, alumina, and potash, or in other words,
a double silicate of alumina and potash.
The change to kaolinite is brought about by weathering agents oi
the atmosphere which are continually at work on the minerals of the
earth's crust, disintegrating them or converting them into new uiiu-
1 The flint clays, though nearly pure kaolinite, possess little or no plasticity.
12 CLAY DEPOSITS IN XORTH CAROLINA.
eral compounds. The most active weathering agents are oxygen and
carbon dioxide, which by percolating waters are carried into the
most remote cracks and crevices of the rocks, and attack the various
mineral compounds, simply oxidizing some, decomposing others and
carrying part of their elements off as carbonates, while silica may be
left behind.
Under the action of these weathering agencies the feldspar is decom-
posed, the potassium being removed in the form of carbonate, while the
silica and alumina remain behind, and with water form the hydrated
silicate of alumina or kaolinite, whose composition is expressed by the
formula A1203, 2Si02, 2II20; or in the proportions of silica (Si02)
46.3^, alumina (A1203) 39. 8$, water (H20) 13.9^.
It sometimes happens that the percentage of alumina in clay is over
39.8, as in the case of many of the Missouri flint-clays, and TTheeler has
suggested that they may be mixtures of kaolinite and pholerite.1 The
latter is an amorphous variety of the former and contains -±5^ of
alumina.
The purity of a clay as formed will depend largely on the nature of
the parent rock or the associations of the feldspar. This mineral fre-
quently occurs in large vein-like masses, in which case its decomposition
would yield a bed of nearly pure kaolin, but more frequently it is asso-
ciated with quartz, or with quartz and mica, etc. When these pegma-
tite or granite veins decompose, the result is a bed of kaolin with par-
ticles of angular quartz and flakes of mica, etc., scattered through it.
These mineral impurities can usually be separated by washing.
Beds of kaolin occurring in or very close to their place of origin are
known as residual clays, and they may represent the purest as well as
the most impure forms of clay. The mineral impurities commonly
found in residual clays are feldspar, quartz, mica, garnet, hornblende,
augite, rutile, etc. Residual clays may form small vein-like masses,
or be of enormous extent. The kaolins near \Vebster and Sylva are
examples of the former, the surface clays around Greensboro of the
latter.
In the erosion of the earth's surface the residual clay is washed down
into the lakes and seas, where it is deposited in the form of a sediment,
but with the addition of many impurities.
Clays thus deposited are known as sedimentary clays, and are usually
far more plastic than the residual clays mentioned above.
The clays of the Cretaceous and Tertiary formations bordering the
Atlantic coast are all of sedimentary origin. Shales are simply har-
dened clays, their rock-like character being due to their having been
buried more or less deeply under other sediments formed subsequent
iMo. Geol. Surv., XI, 1897.
THE ORIGIN OF OkAY. 13
to them. On grinding them to a powder and mixing them with water,
they become plastic just like other clays.
By metamorphism a shale may lose its chemically combined water,
develop a cleavage, and become converted into a slate. It is then no
longer possible to develop any plasticity by grinding and mixing with
water.
Sedimentary clays may vary widely in their nature, even in the
same formation and within small areas. This is due to the variations in
direction and velocity of currents in the bodies of water where they
were deposited, for the finer clay would only be dropped in quiet water,
while where currents existed coarse sand only might be deposited.
Variations in the current at the same point would produce alter-
nating beds of clay and sand, while similar causes might develop large
lenses of clay, free from sand or comparatively so, surrounded by coarse
sand beds. The kaolin deposits of Aiken,. South Carolina, and the
black clays exposed in the bluffs at Prospect Hall, Xorth Carolina, are
examples of this.
Sedimentary clays may be either soft or hard. In the latter case
they are known as shales. Shales, on account of their rockdike con-
dition, are frequently deceptive, yet when ground and mixed with
water they possess the same plasticity as soft clay. On account of the
fusible impurities which they frequently contain, they are found to
be admirably suited to the manufacture of vitrified wares, but in Xorth
Carolina no shale deposits have yet been developed which are suitable
for the manufacture of clay products.
As clays show ail gradations from the purest kaolins to the most
impure brick clays, it is hard to draw any sharp lines of division be-
tween the kinds of clay used for one purpose or another, and conse-
quently no classification is here given.
As before stated, kaolinite forms the base of al] clays, and the rest
of the clay is composed chiefly of the two minerals quartz and feld-
spar. The relative proportion of these three can not be calculated
from the ordinary analysis, but if the amount of residue insoluble
in sulphuric acid and sodium hydroxide be determined, and this latter
analyzed for alumina, potash and soda, it is possible to calculate
the amount of clayd)ase, quartz and feldspar present in the clay. This
determination is of special importance in the case of clays used for the
manufacture of porcelain, white earthenware, stoneware, tiles, and
refractory wares.
The amount of clay-base may vary within wide limit-. In a strictly
pure kaolin it should theoretically be 10(K, but seldom exceeds tuv,.
On the other hand, it may get as low as 5 or 10 per cent., and in this
instance the material would resemble a sand more than clay. The per-
centage of feldspathic detritus is seldom large.
14 CLAY DEPOSITS IN NORTH CAROLINA.
In kaolins of great purity the clay substance consists of kaolinite, but
in impure clays the term is generally taken to mean the finest clay par-
ticles, viz., those under jjtq inches diameter. In impure clays the
clay substance, which may contain both ferric oxide and lime, often
forms the most plastic portion of the mass.
In the North Carolina clays the variations in clay substance and free
sand (quartz and feldspar with some mica) are shown by the following
extremes :
Clay substance.
Washed kaolin, Webster (53) 96.81 %
Bottom clay, Prospect Hall (12) 85.02%
Crude kaolin, Bosticks Mills (20) 47.14%
Free sand (quartz and feldspar).
Black clay, Prospect Hall (12) 15.05%
Kaolin, Bosticks Mills (20) 52.86%,
CHAPTER II.
CHEMICAL PEOPEKTIES OF CLAY.
The properties of clay are of two kinds, (1) chemical and (2) phys-
ical, and the action of clays under heat is not dependent on one class
of properties alone, but upon both acting together. Two clays may
correspond closely in chemical composition, but differ in their phys-
ical properties, and consequently act in a totally different way.
Pure clay, as previously stated, consists of the mineral kaolinite.
This is a white, pearly mineral, crystallizing in the monoclinic system,
the crystals presenting the form of small hexagonal plates. Its specific
gravity is 2.2 to 2.6, and its hardness is 2 to 2.5. It is naturally white
in color, and plastic when wet, but very slightly so. A microscopic
examination shows the plates of kaolinite to be collected in little
bunches, which if broken apart by grinding increase the plasticity.1 If
kaolin be formed into briquettes of the same shape as those used in test-
ing cement, its tensile strength, as determined by pulling these bri-
quettes apart in a testing machine, is usually 12 to 15 pounds per square
inch — a very low amount when compared with the tensile strength of
more plastic clays. Kaolinite is practically infusible, as much so as
silica or magnesite, but a slight addition of fusible impurities immedi-
ately lowers its refraetiveness.
IMPURITIES IN CLAY.
The impurities in clay are silica, iron oxides, lime, magnesia, potash,
soda, titanic acid, sulphuric acid, phosphoric acid, manganese oxide and
organic matter.2 They are generally present in the clay in the form of
oxides, silicates, carbonates, sulphates, phosphates, etc. The minerals
present in clay containing these impurities may be feldspar, quartz,
limonite, mica, garnet, hornblende, augite, calcite, gypsum, talc, etc.
The impurities in a clay will vary in effectiveness according to the
quantity present and the combination in which they exist. Thus cal-
cium or alkalies if present as silicates may serve as a most useful I lux.
whereas if the calcium is present as carbonate it may be very injurious.
The impurities found in clay may be divided into two classes accord-
ing to their effects: (1) fluxing impurities, and (2) non- fluxing ones.
1 The Clays of New Jersey, N. J. Geol. Survey, 1878. G. H. Cook.
2 All of these impurities are seldom present in the same clay.
16 CLAY DEPOSITS IN NORTH CAROLINA.
FLUXING IMPURITIES.
These include alkalies, ferric oxide, lime, magnesia and silica. Their
effectiveness or fluxing action is in the order given above; therefore, of
two clays having the same physical properties and the same total per-
centage of fusible impurities, the one might be more fusible than the
other on account of having a larger proportion of the more active of the
fluxes in its composition. For some purposes it is desirable as well as
necessary that the percentage of fluxes should be low, not only for
reasons of refractiveness, but also to prevent discoloration of the ware,
as when the clay is used for porcelain manufacture. On the other
hand, when the clay is to be used for paving brick or sewer-pipe, a high
percentage of fluxing impurities is desirable in order to produce a vitri-
fied body. In kaolins the fluxes may be as high as 7^, provided they
do not exert a coloring action. Thus some of the most celebrated por-
celain kaolins have 35$ of feldspar, which means about 5.5$ of potash.
In fire-clay 4 to 5$ is the permissible limit, depending on the physical
properties. For paving brick and sewer-pipe the total fluxes may run
as high as 16$.
The term fluxing impurities should not be misunderstood. All the
substances mentioned below as exerting a fluxing action do not become
effective at the same temperature. Thus quartz is a flux at extremely
high temperatures, while feldspar acts at a lower temperature, and iron
or lime at a lower one still. Furthermore the greater the amount of
feldspar present, the lower the temperature at which the quartz and
kaolinite act on each other, for the feldspar when fused seems to play
the same part that water does in promoting chemical action between
two substances which when dry do not act upon each other.
ALKALIES IX CLAY.
The alkalies present in clays may be of two kinds, viz.: the fixed
alkalies, potash, soda and lithia, and the volatile alkali, ammonia.
Ammonia. — This substance is abundant in moist clay, and is ab-
sorbed by the latter with great avidity. Indeed, it is responsible to a
large extent for the characteristic odor of clay.1 If the ammonia
remained in the clay it would act as a strong flux, but it is rendered
harmless for the simple reason that it passes off as a vapor at a tem-
perature considerably below dull redness, or may even volatilize with
the moisture in the clay during the early stages of burning.
The fixed alkalies, potash, soda, and lithia, will only vaporize at
high temperatures, and consequently their effect must be taken into con-
sideration in all stages of the drying and burning. Lithia is of very
1 F. Senft, Die Thonsubstanzen, p. 29.
CHEMICAL PROPERTIES OF CLAY. 17
rare occurrence and only apt to be present in the rare mica, lepidolite;
it may therefore be left out of consideration.
Potash and soda are present in almost every clay, from a trace up to
nine or ten per cent., with an average of one to three per cent.
The reason for this variation is easily apparent when we consider the
composition of pure clay and its derivation. Kaolinite, it will be
remembered, contains only silica, alumina and water, whereas orthoclase,
the common feldspar, has nearly l7fo of alkalies. The presence in the
clay, therefore, of varying amounts of undecomposed or even partly
altered feldspar would be sufficient to account for the alkalies found in
greater or less quantities in the majority of samples analyzed. Aside
from the feldspar, the only common rock-forming mineral containing
alkalies in abundance is mica. In a few cases potash or soda may be
present in the form of soluble salts. We may, therefore, recognize two
sources of the alkalies, viz., soluble and insoluble compounds.
SOLUBLE ALKALINE COMPOUNDS.
Soluble alkaline salts are very frequently present in clays, though
generally in very small quantities. They may come from the decom-
position of feldspar (as in the case of potassium carbonate), or may have
been introduced by percolating surface waters. In most regions the
soluble alkaline compounds are unimportant and hardly worth atten-
tion; but in areas of little rainfall, where evaporation exceeds precipi-
tation, they become concentrated near the surface. These soluble salts
may give the manufacturer considerable trouble. Unless decomposed
in burning or rendered insoluble in some way, they may form an
unsightly white coating on the surface of a burned brick or other pro-
duct. In a similar manner this crust may interfere with the formation
of a salt glaze by preventing the union of the sodium vapors with the
silica of the clay, or prevent the glaze adhering to the surface of pottery
which is glazed before burning.
Soluble alkaline sulphates are powerful fluxes. They may cause blis-
tering of the ware if the clay is heated sufficiently high to decompose
the sulphate and permit the escape of sulphuric acid gases.
In some clays containing sulphate of iron the latter may be decom-
posed by chemical reactions taking place in the clay and sulphuric acid
set free. This acid is apt to attack the alumina, of the clay-base, and,
if potash, soda or ammonia are present, give rise to potash, soda, or
ammonia alum, which can frequently be detected by tasting the clay.
INSOLUBLE ALKALINE COMPOUNDS.
The minerals feldspar and mica forming this class of alkaline salts in
clay are among the commonest of the rock-forming minerals. The
18 CLAY DEPOSITS IN NORTH CAROLINA.
feldspars are silicates of alumina and potash, or alumina, lime and soda.
Orthoclase is the only species furnishing potash, of which it contains
about 17$, while the lime-soda feldspars have from 4 to 12$ of soda de-
pending on the species.
The orthoclase is by far the commonest of the feldspars, and next
to it in point of abundance come albite and oligoclase, with about 12$
and 9$ of soda respectively. The species of feldspars present in a clay
may have some bearing on its refractiveness, for the soda feldspars are
more fusible than the potash ones.
The micas are complex silicates of aluminium with iron, magnesium,
and potassium. Muscovite, the commonest species of the group, con-
tains nearly 12$ of potash and may at times contain a little soda.
Feldspar is the only serious source of alkalies in clays, however, for
the mica is not always present in very large amounts. Mica alone is
extremely refractory, being unaffected at a temperature of 2550° I\,
while feldspar fuses completely at 2300° F.1
Alkalies, on account of their fluxing properties, especially if in the
insoluble form as silicates, are frequently of an advantage, as they serve,
in burning, to bind the particles together in a dense, hard body, and
permit the ware being burned at a lower temperature. In the manu-
facture of porcelain, white granite and C. C. ware (cream-colored ware),
the alkalies for fluxing are added to the body in the form of feldspar,
provided the kaolin does not already contain a sufficient amount of this
material. Much feldspar is mined in this country for potters' use, all
of it being the potash feldspar.
So far as is known, the alkalies exert no coloring influence on the
burned ware, although if an excess of feldspar be added to a white
burning kaolin, the latter may exhibit a yellowish tint when burned.
In the North Carolina clays the combined alkalies (potash and soda)
vary from .29$ in clay from Spout Springs to 4.62$ in brick clay from
Wilkesboro. The average is 1.50 to 2.5$. The washed kaolins usually
contain under one per cent. The pottery clays of North Carolina have
from 0.68 to 2.82$.
COMPOUNDS OF IRON IN CLAY.
Aside from being a flux, iron oxide is also the great natural coloring
agent of clays in both their raw and burned state. The mineral com-
pounds which may serve as the sources of iron oxides in clays are as
follows :
Silicates: Mica, hornblende, garnet, etc.
Oxides: Limonite, hematite, magnetite.
Sulphides: Pyrite, marcasite.
Sulphates: Melanterite.
Carbonates: Siderite.
i G. Vogt, Bull, de la Soc. Chim. de Paris ; and Chem. News, 1890, p. 315.
CHEMICAL PROPERTIES OF CLAY. 19
The silicate mineral, mica, is missing in very few clays. Of the
oxides, limonite and hematite are frequent impurities, and are often
introduced from the surface by percolating waters, or may result from
the decomposition of minerals, such as garnet. This fact is noticeable
in some of the less pure portions of the kaolin beds at Webster, North
Carolina. The iron oxides color the raw clay various shades of red
and yellow. Pyrite is frequently present in clays, especially in many
stoneware and fire-clays, its yellow, glittering metallic particles being
easily recognizable. When disseminated through the clay in small
grains it may be difficult to separate except by careful washing; but
when occurring in lumps, popularly known as " sulphur balls/' it is
much easier to extract. If the finely disseminated pyrite remained in
the clay, it would be found after burning that the clay was dotted with
fused spots of silicate of iron. Many of the first speckled brick so
extensively used at the present time were made in this manner.
The pyrite may readily become oxidized to the soluble sulphate of
iron, which, if present in sufficiently large amounts, imparts an inky
taste to the clay. Pyrite being such a strong flux, the addition of
1-J to 2$ by weight, according to Wipplinger,1 may exert a noticeable
effect in the increase of its fusibility.
In all the classes of iron compounds mentioned above, the iron is
present in one or two conditions, viz. as a ferrous or ferric salt; and
the fusibility of the clay depends somewhat on this condition, ferrous
salts being more fusible than ferric salts. In burning any clay the
ferrous salt will be changed to the ferric salt, provided the action of the
fire is oxidizing. If the fire exerts a reducing action, the same clay will,
under these conditions, fuse at a lower temperature.
Ferric silicate may be an original mineral impurity of the clay, but
many ferric compounds in clays result from the oxidation of ferrous
carbonate or ferrous hydrate in clay which has been introduced in solu-
tion. The presence of ferric hydrate in clay increases its absorptive
power for gases and solutions. On burning, the hydrate is of course
converted into an oxide.
If treated to an oxidizing fire, the presence of ferrous salts need not
therefore be considered, provided the heat is raised high enough to
oxidize them. The rapidity with which the temperature is raised is
important, for if the heat is raised too quickly the outer portion of the
clay may shrink and become dense before the air has had time to
permeate the clay and oxidize the iron in the centre of the body. This
is the cause of black cores sometimes seen in bricks whose surface is
red. This rapid heating may also bring about a differential shrinkage
between the interior and exterior of the brick and cause cracking.
1 Keramik, p. 26.
20 CLAY DEPOSITS IN NORTH CAROLINA.
Uiiburnecl clays may be yellow, blue, brown, red or gray in color,
depending on the relative amounts of ferrous and ferric salts present.
The same variety of shades and colors is produced in burning. Fer-
rous oxide (FeO) alone produces a green color when burned, while
ferric oxide (Fe203) alone may give a purple, and mixtures of the two
may produce yellow, cherry-red, violet, blue and black,1 a fact which is
of the greatest importance to manufacturers of unglazed wares. The
more intense the heat the deeper the color produced by the iron.
Seger 2 found that combinations of ferric oxide with silica produced
a yellow or red color, while similar compounds of the ferrous salt showed
blue and green.
The black coloration by iron produced by hard firing is often to be
seen on breaking open the arch bricks of a brick kiln. The surface of
these bricks may get black, due to the dust and ashes of the fire sticking
to it.
The bleaching of the iron color by the presence of lime is to be seen
in many calcareous clays, as described under lime. It may sometimes
happen, however, that a calcareous clay when burned does not become
buff, but shows a red surface, as if there were no lime present to neu-
tralize the iron color.
In such an instance as found by Seger, the core of the brick may
show the expected buff color. This was brought about by the sulphuric
acid vapors from the fuel uniting with the lime of the clay to form
calcium sulphate, thus preventing its union with the ferric oxide.
The percentage of ferric oxide permissible or desirable in a clay
depends on the quality of the latter. Kaolins, to be used in the manu-
facture of white ware, should have under 1$ if possible, although many
with 1.5$ produce excellent results. A greater percentage might be
present, provided there was also present three times as much lime to
neutralize its color.
If a kaolin has enough ferric oxide to produce a faint yellowish tinge
when burned, by burning it in a reducing atmosphere the color will be
bluish, and will be far less noticeable. The reduction is accomplished
by letting less air into the kiln, and the production of a smoky fire.
The North Carolina washed kaolins contain from .28$ to 1.86$; the
unwashed, 1.14$ to 1.86$; the pottery clays from 2.88.^ to 5.48$.
The total range of ferric oxide in the seventy-three samples of North
Carolina clays which were tested was from .28$ to 11.79^, with an
average of 1.5$ to 5$.
LIME IN CLAYS.
Lime is a common detrimental or fluxing impurity of most medium
or low grade clays. It may be present in one of three conditions, viz. :
1 Keramik, p. 258. 5 RotizUatt, 1874, p. 16.
CHEMICAL PROPERTIES OF CLAY. 21
a. As a silicate, such as in the feldspars.
b. As a simple carbonate, limestone or calcite, or in the form of a
double carbonate, as dolomite.
c. As a sulphate, such as gypsum.
The first two of these are primary mineral constituents of the clay,
the third is of secondary origin and results from chemical action taking
place in the clay.
The presence of lime as a silicate in clay is probably the form in
which it usually occurs, especially if the clay has been derived wholly
or in part from a region of feldspathic rocks. The common feldspar,
orthoclase, contains no lime, so that it probably comes from the lime-
soda feldspars. There are other silicates containing lime, but their pres-
ence is usually more difficult to prove with certainty.
When present as a silicate, lime acts as a flux, but it is less liable to
exert a decolorizing action on the clay, by the formation of a double
silicate of iron and lime, except at higher temperatures.
Calcium carbonate is very common in clays which have been derived
in part from limestone areas, or it may result from the decomposition
of lime-bearing feldspars. Its presence may be usually determined by
treating the clay with muriatic acid, which produces effervescence if
more than 4 or 5$ of calcium carbonate is present.
Lime if present in the form of lumps or pebbles is very injurious,
and should be removed by screening or washing. Finely divided lime
though, if not present in too large amounts, may be harmless. Clays
with 20 to 25$ of calcium carbonate may be used for common or even
pressed bricks, and also for earthenware. In the latter case the same
clay can often be utilized for glazing the pottery, requiring only the
addition of some fluxes.
EFFECT ON THE BRICK OF CALCIUM CARBONATE IN CLAY.
When occurring as carbonate in clay, lime becomes far more injuri-
ous. If the clay is under-burned, the calcium carbonate will be simply
broken up into carbon dioxide and lime. The former escapes, but the
lime, on the cooling of the brick, slakes, that is to say, it absorbs water
from the air, and swells, thus frequently bursting the brick.
If, however, the clay is thoroughly burned, the calcium carbonate
after being decomposed unites with any free silicate that may be
present and forms silicate of lime or probably also silicate of lime and
alumina. If iron oxide is present, the lime takes it also into combina-
tion and thereby destroys its coloring action, giving a buff product
instead of a red one, as would be the case if the iron oxide remained
free. It should also be stated, however, that a low percentage of iron
oxide in the clay without the presence of lime will also give a buff-
colored ware. This is the case with manv stoneware clays.
22 CLAY DEPOSITS IN NORTH CAROLINA.
In high-grade clays large amounts of lime do not have to be consid-
ered, for such materials cannot be used, but in the manufacture of build-
ing brick, or pressed brick, terra-cotta, etc., it is frequently necessary to
use a clay containing large percentages of lime, either from necessity or
to obtain a cream-colored ware. It therefore becomes a matter of
importance to know how much lime is permissible in a clay for this pur-
pose. In general, it may be said that a good brick can be made from a
clay containing 20 to 25$ of calcium carbonate, provided it is evenly
distributed through the clay and in as finely a divided state as possible.
Some clays contain lime in angular fragments or pebbles, which can
be frequently removed by screening.
Aside from lowering the fusibility of a clay to a marked extent, lime
also exerts a powerful effect on its shrinkage.
Seger1 found that calcareous or marly clays required usually only
20 to 24$ of water to convert them from a dry condition into a workable
paste, whereas other clays needed 28 to 35^ of water to accomplish the
same change. Furthermore, as calcareous clays lost not only combined
water but also carbon dioxide in burning, the bricks were the more
apt to be light and porous, and this increased with the amount of lime
present. They also shrink much less than other clays up to the points
of incipient fusion. This low shrinkage may become zero, and the
brick swell instead of shrinking. He also found that the difference
between the points of incipient fusion and viscosity was so small that
it was extremely difficult to bring a kiln of bricks made from calcareous
clay to vitrification without melting a large number.
Seger claims that the presence of calcium carbonate and ferric oxide
in the proportions of 3:1 is sufficient to produce a buff color.
Many clays contain calcium in the form of gypsum, the hydrated
calcium sulphate. It generally originates from the action on calcium
carbonate by sulphuric acid obtained by the oxidation and leaching of
pyrite in the clay. Gypsum frequently discloses its presence by the
formation in the clay of crystals or masses of its transparent variety,
selenite. It also not uncommonly occurs in masses of parallel fibres
filling cracks or cavities in the clay.
It serves as a flux, but may do considerable damage in burning by
its disintegration, the sulphuric acid thus set free causing in its escape
blisters on the surface of the wares.
There is another method by which lime may be introduced into clay,
and that is absorption. This may occur when a clay deposit rests on
a limestone or marl formation, and the lime being taken into solution
by the percolating waters is soaked up by the clay. In this event the
lower layers of the clay would be more calcareous than the upper ones.
1 Gesammelte Schrift, p. 265.
CHEMICAL PROPERTIES OF CLAY. 23
Few of the North Carolina clays are very calcareous. Out of the
seventy-three samples examined the lime varied from .1$ in the clay
at Prospect Hall to 2.55$ in Kirkpatrick's clay at Greensboro. This
latter is exceptionally high, for most of the North Carolina clays contain
under 1$.
Its action, therefore, in all of the samples tested amounts to very
little.
Marly clays are known to occur in the coastal plain formation near
the coast, but none of these have been tested.
MAGNESIA IN CLAYS.
Magnesia rarely occurs in clays in the same quantity as lime; in fact,
it rarely exceeds 2$. In the North Carolina clays, however, of which
samples were examined it seldom exceeds .75$, and is generally present
in about the same quantity as the lime.
Magnesia may be derived from the same classes of compounds as
lime, viz. silicates, carbonates and sulphates.
The silicates are probably by far the most abundant form of its occur-
rence in clay and are represented by the minerals mica, chlorite, and
hornblende (all scaly minerals) containing respectively 20-25$, 15-25$,
and 15$ of magnesia. The mica scales may be prominent in many
clays, and chlorite scales, if very abundant, might even tend to color
the clay green. Hornblende is mostly present in clays derived from
rocks of a very basic composition (that is, with a low silica percentage),
and the same may be said of pyroxene, which, however, is less common
than the hornblende.
Dolomite, the double calcium-magnesium carbonate, has been men-
tioned under the description of lime (p. 21).
Magnesium sulphate, or epsom salts, occurs sparingly in clays. It
is mostly to be found in those clays where sulphuric acid, set free by
the decomposition of pyrite, has attacked magnesium carbonates. The
presence of magnesium sulphate can frequently be detected by the
bitter taste which it imparts to the clay.
As far as the effects of magnesia are concerned with the chemical
properties of clay, they are probably the same as lime. This, however,
can only be stated with a reasonable amount of certainty, for magnesia
is generally present in such small amounts that its actual effect cannot
be detected.
NON-FLUXING IMPURITIES.
These include silica, titanic oxide, organic matter, and water. Both
silica and titanic oxide at high temperatures are fluxes.
24 CLAY DEPOSITS IN NORTH CAROLINA.
SILICA IN CLAYS.
Chemical analysis distinguishes two classes of silica, viz. (1) that com-
bined with aluminium in kaolinite, and (2) sand. The latter includes
quartz, and silica in combinations with various bases as in feldspar and
mica (excluding kaolinite). The two kinds of silica included in this
second class are insoluble in sulphuric acid and sodium hydroxide. If
this residue be further analyzed, it is possible to calculate the amount of
silica present as quartz and that contained in the clay in the form of
feldspar or mica. This is frequently an important matter, for the con-
dition of the silica may influence the fusibility of the clay to a marked
degree.
Free silica or quartz is present in all clays in variable amounts.
Cook * found a minimum of 0.2 of one per cent., and gives 5$ as the
average in the Woodbridge fire-clays. Wheeler2 gives the minimum as
0.5 of one per cent, in the flint clays, and the sand as 20 to 43$ in the
St. Louis fire-clays, and 20 to 50$ in the Loess clays.
Twenty-seven samples of Alabama clays contained from 5 to 50$ of
insoluble residue, mostly quartz.8
Seventy North Carolina clays had from 15.05 to 70.43$ insoluble
residue; while of three samples of which a rational analysis was run
the percentage of sand was from 24.55 to 56.58$, and the quartz per-
centage in these ran from 16.58 to 49.06$, and the feldspathic detritus
from 7.52 to 16.05$.
Free silica is considered by Bischof * to exert a fluxing action at high
temperatures, that is, over 2800° F.
The most important effects of free silica and sand are directed towards
the physical properties of clay. They lessen the plasticity, diminish
the tensile strength and also the shrinkage. If silica is present in ex-
cess and in grains of large size, it may cause the clay to expand in
burning. Quartz in fine grains lessens the shrinkage less than when
present in large ones.
TITANIUM IN CLAYS.
Titanium is probably of widespread occurrence in clay, though never
present in great quantity; it may be derived from rutile (TiOo") or
ilmenite (titaniferous iron ore). It was formerly looked upon as a
rare element and a non-detrimental impurity, but this idea of its rarity
has resulted from the fact that it is usually overlooked in chemical
analyses. According to Seger, it is often present in clay slates and
bauxites. Its effect on the refractiveness of a clay has always been
misunderstood, although its action was considered similar to silica.
1 N. J. Clay Rept., 1878, p. 213. 2 Mo. G-eol. Surv., XI, p. 54.
3 Forthcoming- Bulletin of Alabama Geological Survey. * Die Feuerfestcn Tlwjie. 1896.
CHEMICAL PROPERTIES OF CLAY. 25
Although the determination of titanium in clay requires no difficult
methods, it has, as a rule, not been determined in the chemical analyses
of clay except when specially desired.
In order to determine definitely what the effect of titanium was,
Seger and Cramer1 took a sample of Zettlitz kaolin (which has 98.5$
of clay substance) and mixed two samples of it with respectively 5$ and
10 fc of silica, and two other samples of the kaolin with respectively 6.65$
and 13.3$ of titanic oxide. These samples were molded into pyramids,
which were heated to a temperature above the fusing point of Avrought
iron with the following results :
1. Pure Zettlitz kaolin burned to a white, sharp-edged, dense body.
2. 100 pts. kaolin and 10% silica burned white.
3. " " " " 5% "
4. " " " 6.65% titanic oxide softened in heating aud showed a
blue fracture.
5. " " " '* 13.3% titanic acid fused to a deep blue enamel.
It will therefore be seen that titanium acts as a flux at lower tem-
peratures than silica, and calls to mind the fact that the blue color
given to some stoneware clays by hard firing may not be due always to
iron oxide.
ORGANIC MATTER IN CLAYS.
This is commonly noticed in many clays by the black color which it
imparts to them, but the clay may also be colored brown or blue from
the same cause.
The organic matter generally consists of finely divided pieces of plant
tissue, or large pieces of stems and leaves, which settled in the clay
during its deposition. All surface clays contain plant roots in their
upper layers, but these do not always exert a coloring effect.
Clays colored by organic matter, and containing no iron, burn white
as the plant tissue burns off at a bright redness, but if such a clay is
heated too quickly the surface of the piece becomes dense before all of
the organic matter has had time to escape from the interior, and the
latter remains dark colored. The presence of iron may be masked by
organic matter, so that the clay burns red, as-is_the case with the clays
from Prospect- Hall, on the Cape Tear river. Organic matter is sel-
dom determined separately in chemical analysis, but its quantity may
often be judged approximately from the relation between loss on igni-
tion and alumina.
Organic matter exercises the important property of increasing the
plasticity, but all clays having organic matter are not necessarily plastic,
for the presence of much sand may render such a clay very Iran, like
the Prospect Hall clays.
1 Ges. Schr., p. 411.
26 CLAY DEPOSITS IN NORTH CAROLINA.
In the weathering of clays, organic material, by its oxidation and
consequent evolution of carbonic acid, helps to break up the clay.
WATER IN CLAYS.
The water in clay is of two kinds:
1. Hygroscopic water or moisture.
2. Chemically combined water.
Moisture. — This may be as low as .5$ in air-dried clays or reach
30$-40$ in those freshly taken from the bank. In the air-dried speci-
mens of the North Carolina clays it ranged from .08 $ to 3.07$ in the
kaolins, .45$ to 4.50$ in the sedimentary clays, and .95$ to 1.90$ in the
residual brick clays.
Air-drying expels most of the moisture in a clay, and this is accom-
panied by a shrinkage which, in 70 samples tested from North Carolina,
ranged from 2$ to 13.3$. Sandy, coarse-grained clays usually show the
least shrinkage, but some of the fine-grained ones may act in a similar
manner. The amount of water which a dry clay needs in order to
develop an easily worked paste varies from 12$-20$ in lean ones and
25$-35$ for fat clays. The samples of North Carolina clays tested
required from 16$-40$. The more water that a clay absorbs the more
it has to part with in drying and the greater will be the shrinkage. If
the clay is fine-grained, rapid drying may cause it to split from the
active disengagement of steam.
In the manufacture of clay products the moisture is expelled by
exposing the ware to the sun or drying it in heated tunnels. The last
portions of moisture are driven off in the early stages of burning,
known as water smoking, during which time abundant white vapors
can be seen issuing from the kiln.
Combined water is present in every clay. In pure kaolin there is
nearly 14$ of it. In other clays the percentage varies with the amount
of clay-base and hydrates present. In the North Carolina clays the
loss on ignition (which practically amounted to combined water, those
containing organic matter being left out) varied from 4.04$ to 13.40$ in
the washed kaolins, 5.98$ to 9.00$ in the residual clays, and 4.17$ to
11.08$ in the sedimentary ones.
Combined water is driven off at a low red heat, and when this takes
place the clay begins to suffer an additional loss in volume or shrinkage.
It is a curious fact that while the amount of combined water does not
seem to stand in any close relation to the plasticity of a clay, neverthe-
less, when once driven off, the clay can no longer be rendered plastic
by the addition of water. The fire shrinkage in the North Carolina
clays varied from 2$-12$.
CHEMICAL PROPERTIES OF CLAY. 27
METHODS EMPLOYED IN MAKING CLAY ANALYSES.
The following brief statement of the methods employed in making
the analyses of clays for this report has been prepared by Dr. Charles
Baskerville, by whom the analyses were made:
Moisture. — Two grams are heated in a platinum crucible at 100° C.
until they show a constant weight. The loss is reported as moisture.
Loss on Ignition (combined water, and sometimes organic matter,
etc.). — The crucible and clay are heated with a blast lamp until there
is no further loss in weight.
Alkalies. — This same portion of clay, which has been used for de-
termining moisture and loss, is treated with concentrated sulphuric and
hydrofluoric acids until it is completely decomposed. The acids are evap-
orated off by heating upon the sand-bath. The cooled crucible is washed
out with boiling water to which several drops of hydrochloric acid have
been added. The solution after being made up to about five hundred
cubic centimetres is boiled, one-half gram ammonium oxalate added and
made alkaline with ammonium hydroxide; the boiling is continued until
but a faint odor of ammonia remains. The precipitate is allowed to
settle and is separated from the liquid by filtering and washed three
times with boiling water. The filtrate is evaporated to dryness and
ignited to drive off ammonium salts. The residue is treated with five
cubic centimetres of boiling water, two or three cubic centimetres of
saturated ammonium carbonate solution are added and the whole is
filtered into a weighed crucible or dish. The precipitate is washed
three or four times with boiling water and the filtrate evaporated to
dryness. Five drops of sulphuric acid are added to the residue and
then the crucible or dish is brought to a red heat, cooled in a desiccator,
and the alkalies are weighed as sulphates.
To separate the alkalies, the sulphates are dissolved in hot water,
acidified with hydrochloric acid, sufficient platinum chloride added to
convert both the sodium and potassium salts into double chlorides; the
liquid is evaporated to a syrup upon a water-bath, eighty per cent,
alcohol added, and filtered through a Gooch crucible or upon a tared
filter paper. The precipitate is thoroughly washed with eighty per
cent, alcohol, dried at 100° C. and weighed; the potassium oxide is cal-
culated from the double chloride of potassium and platinum.
When magnesium was present to as much as one-half of one per cent,
the magnesium hydroxide was precipitated with barium hydroxide solu-
tion, and the barium in turn removed by ammonium carbonate. When
the amount of magnesium was less than the amount named, this por-
tion of the ordinary process was not regarded as necessary.
Silica. — Two grams of clay are mixed with ten grams of sodium car-
bonate and one-half gram of potassium nitrate and brought to a calm
2S CLAY DEPOSITS IN NORTH CAROLINA.
fusion in a platinum crucible over the blast lamp. The melt removed
from the crucible is treated with an excess of hydrochloric acid and
evaporated in a casserole to dryness upon a water-bath, and heated in
an air-bath at 110° C. until all the hydrochloric acid is driven off.
Dilute hydrochloric acid is added to the casserole now, and the solution
brought to boiling and rapidly filtered.^ The silica is washed thor-
oughly with boiling water and then ignited in a platinum crucible,
weighed, and moistened with concentrated sulphuric acid. Hydro-
fluoric acid is cautiously added until all the silica has disappeared. The
solution is evaporated to dryness upon a sand-bath, ignited and weighed.
The difference in weight is silica.
Iron Sesquioxide.- — The filtrate from the silica is divided into equal
portions. To one portion in a reducing flask is added metallic zinc and
sulphuric acid. After reduction and filtration to free the liquid from
undissolved zinc and carbon, the iron is determined by titration with a
standard solution of potassium permanganate.
Aluminium Oxide. — To the second portion, which must be brought
to boiling, ammonium hydroxide is added in slight excess, the boiling
continued from two to five minutes, the precipitate allowed to settle
and then caught upon the filter, all the chlorides being washed out with
boiling water. The precipitate is ignited and weighed as a mixture of
aluminium oxide and iron sesquioxide. The amount of iron sesqui-
oxide already found is taken from this and the remainder reported as
alumina.
Calcium Oxide.— -The filtrate from the precipitate of iron and alum-
inium hydroxides is concentrated to about two hundred cubic centi-
metres, and the calcium precipitated in a hot solution by adding one
gram of ammonium oxalate. The precipitate is allowed to settle dur-
ing twelve hours, filtered and washed with hot water, ignited and
weighed as calcium oxide. When the calcium is present in notable
amounts, the oxide is converted into the sulphate and weighed as such.
Magnesium Oxide. — The filtrate from the calcium oxalate precipi-
tate is concentrated to about one hundred cubic centimetres, cooled and
the magnesium precipitated by means of hydrogen disodium phosphate
in a strongly alkaline solution, made so by adding ten cubic centimetres
of ammonium hydroxide (0.90 sp. gr.). The magnesium ammonium
phosphate, after standing over night, is caught upon an ashless filter,
washed with water containing at least five per cent, ammonium hydrox-
ide, burned and weighed as magnesium pyrophosphate.
The insoluble residue is determined by digesting two grams of clay
with twenty cubic centimetres of dilute sulphuric acid for six or eight
hours on a sand-bath, the excess of acid being finally driven off. One
cubic centimetre of concentrated hydrochloric acid is now added and
CHEMICAL PROPERTIES OF CLAY. 29
boiling water. The insoluble portion is filtered off, and after being
thoroughly washed with boiling water is digested in fifteen cubic cen-
timetres of boiling sodium hydroxide of ten per cent, strength. Twenty-
five cubic centimetres of hot water are added and the solution filtered
through the same filter paper, the residue being washed five or six
times with boiling water. The residue is now treated with hydro-
chloric acid in the same manner and washed upon the filter paper, and
free from hydrochloric acid, is burned and weighed as insoluble residue.
A portion of this is treated as the original clay for silica, aluminium
oxide, and iron oxide. Another portion is used for the determination
of the alkalies in the insoluble residue.
Titanic Oxide. — One-half gram clay is fused with five grams potas-
sium bisulphate and one gram sodium fluoride in a spacious platinum
crucible. The melt is dissolved in five per cent, sulphuric acid. Hy-
drogen dioxide is added to an aliquot part and the tint compared with
that obtained from a standard solution of titanium sulphate.
Sulphur (total present). — The sulphur is determined by fusing one-
half gram of clay with' a mixture of sodium carbonate, five parts, and
potassium nitrate, one part. The melt is brought into solution with
hydrochloric acid. The silica is separated by evaporation, heating
resolution, and subsequent filtration. Hydrochloric acid is added to the
filtrate to at least five per cent, and the sulphuric acid is precipitated by
adding barium chloride in sufficient excess, all solutions being boiling
hot. The barium sulphate is filtered off and washed with hot water,
burned and weighed as such.
Ferrous Oxide is determined by fusing one-half gram clay with five
grams sodium carbonate, the clay being well covered with the car-
bonate, the top being upon the crucible. The melt is dissolved in a
mixture of dilute hydrochloric and sulphuric acids in an atmosphere
of carbon dioxide. The ferrous iron is determined at once by titration
with a standard potassium permanganate solution.
The rational analysis is made from the results obtained by the chem-
ical analysis in the following way: The alumina found in the portion
insoluble in sulphuric acid and sodium hydroxide is multiplied by
3.51. This factor has been found to represent the average ratio be-
tween alumina and silica in orthoclase feldspar; therefore the product
just obtained would represent the amount of silica that would be presenl
in undecomposed feldspar. The sum of this silica with the alumina.
ferric oxide and alkalies equals the " felclspathic detritus.'' The dif-
ference between silica as calculated for feldspar and the total silica in
the insoluble portion represents the " quartz " or " free sand." The
difference between that portion of the sample insoluble in sulphuric
acid and sodium hydroxide and the total represents the "clay sub-
30 CLAY DEPOSITS IN NORTH CAROLINA.
stance." The method of analysis used to determine the mineralogical
character of the clay is called the rational method, and when carried
out in its simplest form, determines the amount of clay substance or
kaolinite, quartz, and feldspar present in the clay. If carried out more
completely it enables us to calculate the amount of calcite or limestone
(calcium carbonate), iron oxide and even mica in the clay.
THE RATIONAL ANALYSIS OF CLAY.
In the ordinary or ultimate quantitative analysis of clay the latter
is regarded as being composed of a given number of elements or oxides
of them, in given amounts, but gives no clue as to the condition in
which these substances exist, viz., whether they are present as oxides,
silicates, carbonates, etc., a point which it is often of the greatest im-
portance to know. Thus, as pointed out under calcium (Chemical Prop-
erties of Clay), if this substance is present as a carbonate it may be
extremely injurious, but if combined with silica in the form of feld-
spar it is beneficial, serving as a binding material (p. 21). Or, again,
the ultimate analysis does not point out the condition of the silica,
whether present as quartz (serving to lessen the shrinkage) or as a con-
stituent of feldspar (serving as a flux). A high percentage of total
silica in an ultimate analysis may be caused by an excess of feldspar
and not always by quartz.
The inferences which may be drawn from the ultimate analysis of a
clay are:
1. It may be said in general that the greater the amount of ferric
oxide in a clay the deeper red it will burn at any given temperature.
Small percentages of ferric oxide will only color the clay yellow.
2. We can see from the ultimate analysis whether there is sufficient
lime present to counteract the effect of the feme oxide.
3. It is possible to gain an approximate idea of the fusibility of the
clay from the total fluxes present, and also to see whether it is the
weaker or more powerful fluxes that are present.
4. A very high silica percentage generally indicates a sandy clay.
5. Clays high in alumina and combined water as a rule shrink con-
siderably in burning.
There are, however, many physical properties which the ultimate
analysis does not explain, because they are dependent largely on the
mineralogical composition.
It frequently happens that two clays show very close chemical com-
position, but act entirely unlike, and the explanation is almost self-
evident, viz., that the elements present in both clays are differently
combined.
The following table of analyses illustrates this, viz. :
CHEMICAL PROPERTIES OF CLAY. 31
1. That clays with the same ultimate composition may show a dif-
ferent rational composition (see analyses a and b below).
2. That clays may agree in both their ultimate and rational analysis
(see b and c below), but this is not very frequent:
Silica 47.60
Alumina 34.00
Ferric oxide 1.30
Lime trace
Magnesia .50
Alkalies 3.00
Loss on ignition 13.60
Total 100.00
Clay substance 88.34
Quartz 8.95
Feldspar 2.73
b.
c.
46.61
46.82
36.47
38.49
2.81
1.09
.14
trace
1.44
1.40
12.80
12.86
100.17
100.G6
96.08
96.55
1.93
2.30
1.99
1.15
100.02 100.00 100.00
The practical bearing of the rational analysis has thus far been
chiefly for those branches of the clay-working industry using mostly
materials of considerable purity, as in the manufacture of porcelain,
white earthenware, fire-bricks, glasspots and encaustic tiles; and its
importance lies in the fact that two bodies having the same rational
composition will usually act pretty much alike. That is to say, that
other things being equal, they will, for instance, usually have the same
shrinkage in burning.
In the manufacture of porcelain the body generally consists of a mix-
ture of kaolin, quartz and feldspar. Suppose that the mixture' has 60
parts of feldspar and 200 parts of kaolin, the latter having the rational
composition of the Wests Mill, 1ST. C, material, viz.:
Clay substance, 83.39; quartz, 14.98; feldspar, 1.58.
This would give us a mixture with rational composition of:
Clay substance, 60.32; quartz, 11.40; feldspar, 24.30.
If now for the Wests Mill kaolin we desired to substitute that from
near Bostick having:
Clay substance, 54.30; quartz, 43.85; feldspar, 1.S2,
and used the same amount as we did of the Wests Mills material, we
should get a mixture having:
Clay substance, 41.77; quartz, 33.31; feldspar, 20.3<>.
32 CLAY DEPOSITS IN NORTH CAROLINA.
This mixture having less feldspar and clay substance, but more
quartz, would probably show less plasticity and less shrinkage. Know-
ing, however, the rational composition of the Bostick kaolin, it is per-
fectly easy to add it in such proportions as will keep our mixture of the
same composition.
In the manufacture of tiles, where one clay body is pressed on to
another, it is highly essential that the two should have the same shrink-
age to prevent cracking during the burning and cooling.
Experiments tend to show that if the two bodies have the same
rational composition their shrinkages will be about the same, provided
there is not much difference in the coarseness of their grain. In porce-
lain and white earthenware manufacture the clays are ground so fine
that this point does not come into consideration.
A rational analysis has been made of all the I^orth Carolina kaolins
tested, and in the other clays the insoluble residue (quartz and feldspar
combined) was determined.
CHAPTER III.
PHYSICAL PKOPERTIES OF CLAY.
These are fully as important as the chemical ones, and sometimes
more so. In Germany the labors of Seger, Bischof, Olschewsky and
others have brought forth the significance which the physical properties
of clays have, and in this country the work of Orton and Wheeler has
corroborated them in many details.
Chemical analysis alone cannot be used as a basis of comparison, but
the physical characters must also be taken into consideration.
While the list of physical properties may be made of considerable
length, there are a number which are of special importance and will
be considered herewith. These are plasticity, fusibility, shrinkage, ten-
sile strength, slaking, absorption, density.
PLASTICITY IN CLAYS.
This is one of the most important properties of clays, for it permits
their being molded into any desired form, which they subsequently
retain.
Plasticity in clays is exceedingly variable. Those possessing little
plasticity are called " lean/7 while those which are highly plastic are
known as " fat " clays.
The cause of plasticity was for a long time supposed to be directly
■connected with the hydrated silicate of alumina, or kaolinite, and clays
high in kaolinite were said to be very plastic and vice versa. This is
plainly not so, as any series of clays tested will demonstrate.
Pure or nearly pure kaolins are very lean, while clays low in alumina
may be highly plastic. ) This may be shown by a few examples drawn
from the North Carolina clays tested, mentioning first that the tensile
strength of a clay (as will be explained later) is closely related to its
plasticity.
The examples to illustrate this point are as follows :
Tensile strength in
Per cent, of pounds per sq. in.
Alumina. Average. Maximum.
Lower clay, Roanoke Rapids (3) 16.09 200 218
Washed kaolin (53) 40.61 20 22
Clay, Spout Springs (17) 32.51 24 29
Prof. G-. H. Cook1 considered that plasticity was due to a plate struc-
1 N. J. Geol. Survey, Kept, on Clays, 1878.
3-i CLAY DEPOSITS IN NORTH CAROLINA.
ture present in the clay, the plates sliding over each other and thus
permitting mobility of the mass without cracking. As kaolinite is prac-
tically the only plate-like mineral omnipresent in the clay, the simple
plate theory does not seem entirely sufficient.
Olschewsky'1 was probably the first to suggest that the plasticity and
cohesion of a clay were dependent on the interlocking of the clay par-
ticles and kaolinite plates, and in this connection used the briquette
method of testing the plasticity or rather obtaining a numerical expres-
sion for it, by determining the tensile strength of the air-dried clay.
The more recent experiments of W. Aleksiejew and P. A. Cremiats-
chenski on the Russian clays2 show that plasticity is not only due to
the interlocking of the clay particles, but also varies with the fineness
of the grain, the extreme coarse and fine ones both having less plas-
ticity.
In this country Wheeler's work on the Missouri clays has substan-
tiated these views.3
Experiments by the writer on the Alabama clays*4 corroborate these
results still further, and the tests of the Xorth Carolina ones also point
in the same direction. The clays southeast of Spout Springs, for ex-
ample, which are very fine-grained, plainly show the lessening effect
on the tensile strength.
Whether, however, the greatest tensile strength depends on the pres-
ence of particles of certain size, or a mixture of different sizes, and, if
so, within what limits these sizes must be, is still to be determined.
Plasticity, whatever may be its exact cause, is an important property
from a commercial standpoint, for it facilitates the molding or burning
of the wares without cracking.
The amount of water required to develop the maximum plasticity
varies. If too little is added, the clay cracks in molding and is stiff and
hard to work. If too much water is used, the paste becomes soft and
retains its shape with difficulty. Lean clays usually require less water
to produce a workable paste than fat ones.
TENSILE STRENGTH OF CLAYS.
To state that the plasticity of a clay is lean, fair, good, or high is
necessarily only approximate and unsatisfactory, and a method by which
the degree of plasticity can be expressed accurately is much to be pre-
ferred.
Various methods for testing the plasticity of a clay have been devised,
but as most of them are practically useless, if for no other reason than
1 Topf . w. Zieg\. 1882, No. 29.
2 Zap. imp. russk. techn. obschtsch., 1896, XXX, pt. 6-7.
3 Mo. Geo!. Surv., XI, 1897, p. 102.
4 The Clay-working Industry in 1896, 18 Ann. Rept. U. S. Geol. Surv., pt. V. p. 1129.
PHYSICAL PROPERTIES OF CLAY. 35
that they are largely influenced by the personal equation, their discus-
sion need not be gone into here, and any one desiring to look them up
is referred to C. Bischof's work, " Die Feuerfesten Thone."
Two methods, however, approach the requirements:
The first consists in forming the clay into a bar of known section and
then noting the load required to crossbreak it.1
The second, devised by Olschewsky,2 consists in molding the clay into
briquettes of the same shape as those used in testing cement, allowing
them to air-dry, and then pulling them apart in a cement testing ma-
chine, noting the number of pounds pull required. Before breaking,
the cross-section of the briquette must be carefully measured and the
tensile strength per square inch calculated, as the clay shrinks in drying.
This is a perfectly rational method and supposes that as plasticity is
dependent on the interlocking of the particles, the tensile strength will
naturally stand in direct relation to it. Even though it is not yet cer-
tain that this is the cause of plasticity, still it is certain that with increase
in plasticity there is a rise in the tensile strength.
In the North Carolina clays the tensile strength varied from 5 lbs.
per sq. in. in a Webster kaolin to 220 lbs. per sq. in. in a brick clay
from Greensboro.
The residual clays tested were all of low tensile strength.
The clays were all ground to pass through a 30-mesh sieve before
being molded into the briquettes.
SHRINKAGE OF CLAYS.
The variable shrinkage of clays in drying has already been mentioned
in the discussion of water in clays. The amount of shrinkage depends
somewhat on the amount of water absorbed or the porosity of the clays.
But coarse-grained clays may absorb much water and yet shrink com-
paratively little. Having larger pores, they will permit the water to
escape more rapidly, and hence can often be dried quicker than fine-
grained ones, from which the water on account of the smallness of the
pores cannot escape so quickly.
If fine-grained clays are dried rapidly, the surface shrinks quicker
than the interior, and cracking may ensue, especially if the clay ha- a
low tensile strength.
The air shrinkage begins as soon as the clay is molded and set out
in the sun or put in a hot tunnel to dry, and continues until the
moisture is driven off.
The fire shrinkage generally commences when the combined water
begins to pass off, or about 1200° F. It varies just as the air shrinkage
did.
1 P. Jochem, Zeitscb. der Verein deutech. Trig., 18P5. - Topi". Zeit., 1882, No. -'•:.
36 CLAY DEPOSITS IN NORTH CAROLINA.
In the North Carolina clays the fire shrinkage was from 2-12$, with
an average of 4-6$.
The fire shrinkage is influenced by several conditions, viz. amount
of combined water, organic matter, and sand. The fire shrinkage in-
creases with the amount of organic matter and combined water in the
clay. Sand diminishes the shrinkage. Lime has the same tendency
and may even make the clay swell a little. Clays containing a large
amount of feldspar, will, instead of showing a steady shrinkage up to
the temperature of complete vitrification or sintering, often exhibit a
temporary increase of volume when the fusing point of the feldspar
(about 2300° F.) is reached.
Between the points at which the moisture has ceased coming off and
that at which the combined water begins to escape, the clay shrinks
little or none at all. Consequently in firing a clay the heat can be
raised rapidly between these two points, but above and below them it
must proceed slowly to prevent cracking the ware.
FUSIBILITY OF CLAYS.
In the heating of a clay, or subjecting it to a gradually increasing
temperature, it not only shrinks but begins to harden. After the
moisture has been driven off the clay bears some handling and is mod-
erately hard, but can be scratched by the finger-nail.
Accompanying the second shrinkage of the clay, beginning at a dull
red heat, there comes an increase in hardness and density, and at a
temperature of from 1500° to 2100° F., depending on the clay, it becomes
very dense, the individual particles are barely recognizable, and the
clay cannot be scratched with a knife. It is still porous, however. This
is the point of incipient fusion. With an increase in the temperature
of from 50° to 200° F., depending on the clay, an additional amount of
shrinkage occurs. The clay becomes hard, dense, impervious, the par-
ticles are no longer recognizable, and the maximum shrinkage has been
attained. This is the point of vitrification or sintering. "With a
further similar rise in temperature the clay becomes viscous or flows.
These three stages are not sharply marked, but with a little practice
the eye can detect the condition which the burned clay has reached.
With few exceptions, the point of vitrification seems to be midway
between incipient fusion and viscosity. The difference in temperature
between these two points varies from 75°-100° F. in calcareous clays,
up to 400° or more in the purer ones. Indeed, the majority of clays
show a difference of 300°-400° F. between incipient fusion and viscosity.
The practical value of this property is at once apparent, for many
clays require to be heated to vitrification, and the greater the margin
between this point and viscosity the better, for a kiln cannot be man-
aged within very narrow limits of temperature.
PHYSICAL PROPERTIES OF CLAY. 37
TEMPERATURE AT WHICH CLAY FUSES.
It may be said in general that, other things being equal, the fusi-
bility of a clay will increase with the amount of fluxes.
This is only to be regarded as an approximate statement, for all the
fluxing impurities do not act with the same intensity.
If the fluxes are the same, a fine-grained clay will fuse at a lower
temperature than a coarse-grained one, because in a clay with fine grain
the particles are closer together, and can interact better chemically when
they become softened by the heat. This fact may be brought out by a
comparison of the pipe-clay from the first pit at Pomona and that at
Spout Springs.
The former is coarse-grained, and, though containing 5.10$ of fluxes,
only vitrifies at 2250° F., while the latter, with only 3.81$ total fluxes,
vitrifies at 2150° because it is very fine-grained.
Several attempts have been made to express the relative fusibilities
of clays numerically, but none of them are wholly satisfactory, as they
do not give a series of numbers expressing the relative fusibilities of
different clays, which stand in the same order as the fusibilities them-
selves.
Until this can be done such formulae have no definite value, and, in
any case, it is more satisfactory to know the actual temperature of fusion
of a clay than to express it in relative terms.
Bischof 1 assumed that refractoriness of a clay is directly as the square
of the alumina and inversely as the silica and fluxes. He therefore
deduced the formula in which F. Q. stands for " Refractory quotient."
v n fAl2OsV
1-^- — Si02XRO"
This only holds good for comparing clays of the same fineness. When
there is a variation in this the formula no longer holds good.
Wheeler * has suggested the formula
F. F.
D + D' + C
in which F.F. is called the Fusibility Factor.
N = sum of non-detrimentals, or silica, alumina, titanic acid, water,
moisture and carbonic acid.
D = sum of detrimental impurities, or iron, lime, magnesia, alkalies,
sulphuric acid, sulphur, etc.
D'=sum of alkalies which Wheeler supposes to have twice the flux-
ing value.
The formula without C was not much more regular in its results
than Bischofs.
1 Die Feuerfesten Thone, p. 71, 1876. * Eng. and Min. Jour., LVIL, 1894, p. 224.
38 CLAY DEPOSITS IN NORTH CAROLINA.
Wheeler therefore adds the term C, which he makes
C = l when clay is coarse-grained and specific gravity exceeds. . .
C = 2 «
CC U U U (C «
" from. . .
....2 to 2.25
C = 3 "
44 44 C£ It U («
" from . . .
.. .1.75 to 2.0
C=2 «
" " fine-grained " "
" above...
r. .2.25
C = 3 "
<< 14 (C K 41 ((
" from. . .
.. .2 to 2.25
C = 4 "
(( 44 44 44 44 44
" from . . .
.. .1.75 to 2.0
This gives better but still not regular results. The insertion of a
term to account for fineness or coarseness is perfectly rational, but the
specific gravity is dependent on the mineral composition of the clay
and therefore indirectly connected with chemical constitution.
MEASUREMENT OF TEMPERATURES.
There are various forms of pyrometers for determining the tempera-
tures, depending, according to their principle, on the fusion of alloys
or single metals, thermo-electricity, fusion, spectro-photometry, expan-
sion, etc. Most of these are unreliable, and for their description one
is referred to any good text-book. Two forms of pyrometer deserve
detailed mention, the one on account of its extreme accuracy and
adaptability in many places where a little care is used, the other on
account of its very fair accuracy, cheapness, as well as ready applica-
bility to practical use.
THE THERMO-ELECTRIC PYROMETER.
Le Chatelier's thermo-electric pyrometer depends on the measure-
ment of a current generated by heating a thermo-pile. The latter con-
sists of two wires, one of platinum and the other of an alloy of 90#
platinum and 10fo rhodium, twisted together at their free ends for a
distance of about an inch, and the next foot or two of their length
enclosed in a fire-clay tube, so that when the couple is inserted into the
furnace only the twisted ends, which are held near the body whose tem-
perature is to be measured, will receive the full heat. The two wires
connect with a galvanometer, the deflection of whose needle increases
with the temperature at the point where the free end of the wire couple
is applied.
For use the instrument has to be first calibrated, but this can be
easily done with a little care.
As at present put on the market, the thermo-electric pyrometer costs
about $180, and this high price has always tended to restrict its use.
There is no reason, however, why one should not be made for about $35.
This pyrometer is accurate to within 5 or 10 degrees Fahr.
SEGER'S PYRAMIDS.
These consist of different mixtures of kaolin and fluxes, which are
compounded so that there shall be a constant difference between their
PHYSICAL PROPERTIES OF CLAY. 39
fusing points. Seger's series were numbered from 1 to 20, and the dif-
ference between their fusing points is 36° F. A later series, introduced
by Cramer, runs from .01 to .022 with a difference of 54° F. between
their fusing points. The higher numbers of the cones have also been
extended up to 36.
These pyramids have been recently recalibrated, and therefore the
fusing points and composition of the different numbers are given here-
with, being taken from the recently issued circular of the Thonin-
dustrie Laboratorium, in Berlin, where these cones were first made.
FUSION TEMPERATURES BASED UPON RECENT RECALCULATIONS FOR SEGER'S PYRAMIDS.
No. of
Cone.
032
021
€20
€19
€18
€17
€16
€15
014
€13
012
€11
€10
09
€8
07
€6
€5
€4
€3
Composition.
Fusion Point
0.5 Na.,0 )
0.5 PbO \
( 2 Si02
( 1 B.Oa
Cent.
590
Fahr.
1094
0.5 Na.,0
0.5 PbO \
0.1Al2O3
( 2.2 Si02
( 1 BP:>,
620
1148
0.5 Na.,0
0.5 PbO f
0.2 A1,03
( 2.4 Si02
j 1 B20:j
650
1202
0.5 Na90 )
0.5 PbO f
0.3 A1203
( 2.6 Si02
I 1 B203
680
1256
0. 5 Na.,0 )
0.5 PbO \
0.4 A1203
(2.8Si02
I 1 B A
710
1310
0.5 Na.,0 }
0.5 PbO \
0.5 A1203
f 3.0 Si02
1 1 B,o3
740
1364
0.5 Na.,0 )
0.5 PbO f
0.55 A1203
J 3. 1 Si02
I 1 B203 -
770
1418
0.5 Na.,0
0.5 PbO f
0. 6 A1203
|3.2Si02
1 1 B A
800
1472
0.5 Na.,0
0.5 PbO j"
0.65 A1.,03
\ 3.3 Si02
I 1 B203
830
1526
0.5 Na.,0 V
0.5 PbO /
0.7Al2O3
J" 3.4 Si02
1 1 B203
860
1580
0.5 Na.,0 }
0.5 PbO j"
0. 75 A1203
\ 3. 5 Si02
1 1 B203 '
890
1634
0. 5 Na,0 )
0.5 PbO f
0.8 A1203
f 3.6 Si02
I 1 B203
920
1688
0.3 K.,0 )
0.7 CaO \
0.2 Fe.,03
0.3 A12"03
j 3.50 Si02
I 0. 50 B203
950
1742
0.3 K.,0
0. 7 CaO \
0.2 Fe203
0.3 A1203
j 3.55 SiO.,
\0.45 B203
970
1778
0.3 K.20 )
0. 7 CaO \
0. 2 Fe203
0.3 A1203
{ 3.60 Si02
"(0.40 B,03
990
1S14
0.3 K20 )
0. 7 CaO J"
0.2 Fe.,03
0.2 A1203
{ 3. 65 SiO.,
} 0.35 B.,03
1010
is;, 0
0.3 K20 !
0.7 CaO f
0.2 Fe203
0.3 A1203
J 3. 70 SiO,
\0.30 B203
1030
L886
0.3 K.,0 \
0. 7 CaO j
0.2 Fe.,0.,
0.3 A1203
f 3. 75 SiO,
\0.25B2O;
1050
L922
0. 3 K.,0 )
0. 7 CaO J"
0.2 Fe203
0.3 A1203
( 3.80 Si02
"j 0.20 B,03
1070
L958
0.3 K.,0 )
0.7 CaO /
0.2 Fe2Os
0.3 A1203
( 3.85 Si02
"/ 0.1:, B903
1090
1994
40
CLAY DEPOSITS IN NORTH CAROLINA.
FUSION TEMPERATURES, ETC.— Continued.
Composition.
Fusion Point.
No. of
Cone.
02
01
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
0.3 K20
0.7 CaO
j
J
0.2Fe2OQ j
0.3 A1203J (
3.90 Si02
0.10 B203
Cent.
1110
Fahr.
2030
0.3 K.,0
0.7 CaO
0.2 Fe203 \
0.3 A1203 (
3.95 Si02
0.05 B203
1130
2066
0. 3 K20
0. 7 CaO
1
0.2Fe2O3 f
0.3 A1203 \
4 Si02
1150
2102
0.3 K20
0.7 CaO
0.2 Fe203 f
0.4 A1203 (
4 Si02
1170
2138
0.3 K20
0.7 CaO
0.05Fe2O3 j
0.45 A1203 (
4 Si02
1190
2174
0.3 K20
0.7 CaO
0.5 Al2034Si02
1210
2210
0.3 K20
0.7 CaO
0.5 Al2Os5Si02
1230
2246
0.3 K,0
0.7 CaO
0.6 Al2036Si02
1250
2282
0.3 K20
0.7 CaO
0.7 Al2037Si02
1270
2318
0.3 K20
0.7 CaO
0.8 Al2038Si02
1290
2354
0.3 K00
0.7 CaO
0.9 Al2039Si02
1310
2390
0.3 K20
0.7 CaO
1.0 Al2O310SiO2
1330
2426
0.3 K20
0.7 CaO
I
1.2 Al20312Si02
1350
2462
0.3 K20
0.7 CaO
1.4 Al20314Si0.2
1370
2498
0.3 K20
0.7 CaO
1.6 Al20316Si02
1390
2534
0.3 K20
0.7 CaO
1.8 Al20318Si02
1410
2570
0.3 K20
0.7 CaO
2.1 Al20321Si02
1430
2606
0.3 K20
0.7 CaO
2.4 Al20324Si02
1450
2642
0.3 K20
0.7 CaO
2.7 Al20327Si02
1470
26 7S
0.3 K20
0.7 CaO
3.1 Al20331Si02
1490
2714
0.3 K20
0.7 CaO
j
3.5 Al20335Si02
1510
2750
0.3 K20
0.7 CaO
3.9 Al20339Si02
1530
2786
0.3 K20
0.7 CaO
4.4 Al20344Si02
1550
2822
0. 3 K20
0.7 CaO
\
4.9 Al20349Si02
1570
2858
0.3 K20
0. 7 CaO
5.4 Al20354Si02
1590
2894
0.3 K20
0.7 CaO
6.0 Al2O360SiO2
1610
2930
0.3 K20
0.7 CaO
6.6 Al20366Si02
1630
2966
PHYSICAL PROPERTIES OF CLAY. 41
FUSION TEMPERATURES, ETC.- Continued.
Composition.
No. of i k
Cone.
™ 0.7 CaO j" '* ai2u3^smu2
27 K20 h on Aifl 200S1O
-7 Q ? CaQ j. ,..U AI2U3-UU&lU5
28 Al2O310SiO2
29 Al2038Si02
30 Al2036Si02
31 Al2035SiOo
32 Al2034Si02
33 Al2033Si02
34 Al2032.5Si02
35 Al2032Si02
36 AL,(X2Si09
Fu
sion Point.
Cent.
Fahr.
1050
3002
1070
3038
1000
3074
1710
3110
1730
3146
1750
3182
1770
3218
1790
3254
1810
3290
1830
3320
1850
3862
"When these pyramids are placed in a kiln or furnace they begin
to soften as the temperature is raised, and as it approaches their fusion
point the cones bend over until the tip is as low as the base. "When
this occurs the temperature at which they fuse is considered to be
reached.
If it is therefore stated that a clay vitrifies at cone 5, it means that the
amount of heat required to make cone 5 bend over is sufficient to vitrify
the clay. In this report it has not been thought advisable to use this
method but to give the actual temperatures. Comparisons can be easily
made by looking up the number of the cone in the foregoing table.
These cones are accurate to within 25°, which is entirely sufficient
for practical purposes. In actual use the cones are set in the kiln at
a point where they can be watched through a peep-hole but will not
receive the direct touch of the flames from the fuel.
It is well to put two or more cones in so that warning can be had of
the approach of the desired temperature.
In order to determine the temperature of a kiln, several cones of
separated numbers are put in, as, for example, .07, 1, and 5. Suppose
that .07 and 1 are bent over in burning, but 5 remains unaltered.
The temperature of the kiln was therefore between 1 and 5. The
next time 2, 3 and 4 are put in. 2 and 3 may be fused, but 4 remains
unaffected. The temperature therefore reached the fusing point of 3,
or 2174° F. If the cones up to about No. 2 are heated too quickly,
they are apt to swell up, and prevent themselves bending over.
Seger's cones are extensively used in Europe, and in America their
application is extending. Their one great advantage is that they indicate
not the actual temperature, but rather its action. Thus cone No. 1 does
not bend over as soon as the temperature of 2102° F. is reached, but only
when this temperature has penetrated the cone. It is not advisable to
42 CLAY DEPOSITS IN NORTH CAROLINA.
use a cone a second time, in case it lias not bent over in a previous burn-
ing. Such cones are apt to bend at a lower temperature.
In porcelain manufacture, cones of the same composition as the glaze
on the ware are sometimes used.
These cones can be obtained for about one cent each from Prof. E.
Orton, Jr., Ohio State University, Columbus, O.
SLAKING OF CLAYS.
"When a lump of clay is placed in water it begins to slake or break
up in a more or less characteristic manner, depending on the nature of
the clay. Some homogeneous clays split into a number of angular
fragments, others into scaly particles, while still others break up com-
pletely into their component grains. The rapidity of slaking varies,
depending largely on the density and toughness of the clays. Some
clays slake completely to pieces in two or three minutes, while others
may lie in water for an hour or two and remain totally unaffected.
This property is of practical importance in two ways. In washing
kaolins or stoneware clays it is desirable that they should fall apart
quickly when thrown into water, and thereby permit a quicker and
more thorough separation of the impurities.
Slaking is also of importance in tempering clays, for the easier they
break up the easier and more thoroughly will they become mixed in the
pugmill.
MINOR PHYSICAL PROPERTIES OF CLAYS.
The other physical properties of clay, such as absorption, fineness of
grain, taste, color, have been mentioned in connection with other prop-
erties and need be but briefly referred to here.
ABSORPTION OF WATER.
The absorption of clays varies of course, some taking up a large
amount of water, which they give off again in drying, with the risk of
cracking the clay unless dried very slowly. The presence of organic
matter, ferric hydrate and ammonia may increase the absorptive power.
The residual clays common throughout the western half of the State
often absorb a large amount of water, without showing much plasticity.
They are coarse-grained and very porous, and show the property not
uncommon to many clays, in that they become more plastic as water is
added up to a certain limit, but a slight addition over this causes the
clay to become soft and decrease rapidly in plasticity.
TEXTURE OF CLAYS.
Fineness of grain, as already mentioned, has an important bearing on
the fusibility of clays. It also diminishes the tensile strength, and,
PHYSICAL PROPERTIES OF CLAY. 43
with few exceptions, requires the clay to be slowly dried, and in burn-
ing to be slowly heated at first. In porcelain manufacture the particles
of clay must be of extreme fineness, and this has often to be brought
about by grinding.
TASTE OF CLAYS.
Tasting a clay will often give a clue to the presence of soluble salts,
such as sulphates of iron or magnesia, which may impart a bitter, inky
taste to the clay. The presence of grit may also be detected by grind-
ing a lump of the clay between the teeth.
COLOR OF CLAYS.
The color of a clay serves only as an indication of its quality within
very wide limits.
Many high-grade clays which burn white are in their original or green
state colored black by the presence of a small per cent of organic matter.
The latter, however, may mask the presence of iron, as in those from
Prospect Hall, which burn to a deep red.
Iron may color a clay green, yellow, red, gray, brown or black,
depending on the condition of its compound, whether ferrous or ferric.
In surface clays it frequently exists in the ferric condition as limonite
or hematite, and imparts a brilliant yellow or red to the clay. E"ot
unfrequently the upper part of a clay bank is yellow or red, due to the
presence of abundant ferric oxide, while the lower portion of it may
be blue or gray from the iron being less oxidized. Many kaolins with a
very small percentage of ferric oxide burn white in oxidizing fire, but in
reducing fire burn gray, due to a reduction of the iron from the ferric
to the ferrous condition.
The colors imparted by the different constituents have been mentioned
under the chemical properties. It should be remembered that in case
the clay does not burn to a color which the analysis would indicate, that
it may be due to the union of the elements in the clay with substances
in the fire gases of the kiln. Many coals contain sulphur. In burning
the sulphuric acid gases are apt to unite with the lime or other sub-
stances in the clay, with formation of sulphates.
DENSITY OF CLAYS.
The specific gravity of a clay varies with its mineralogical composi-
tion, and may run from about 1.75 to 2.60. Thus far it is not known of
itself to have any practical value. In the summary of tests at the end
of the report will be found the specific gravities of the North Carolina
clays here described, determined by Prof. F. P. Tenable.
CHAPTER IV.
GEOLOGY AKD GEOGEAPHY OF NORTH CAROLINA
CLAY DEPOSITS.
The clay deposits of North Carolina belong to two types, residual
and sedimentary, which, with their varieties, may be grouped as follows :
Kesidual : — Kaolins; tire-clays; and impure clays.
('Coastal plain clays, of Cretaceous or Tertiary age.
a j. . ! Sedimentary surface clays (for brick and pottery), mainly along
y j the streams and low-lands, in the Piedmont plateau and moun-
[_ tain counties.
The accompanying outline map (Plate II) indicates the general dis-
tribution of the geological formations in the State, except that no-
attempt is made to separate those of the coastal plain region.
RESIDUAL CLAYS.
These in general are to be found in any portion of the western half
of the State, that being the area underlain by the granitic, gneissic, and
schistose rocks from which they have originated by the decay in situr
as explained under the origin of clay.
The eastern border of this area of crystalline rocks passes through the
counties of Halifax, Eranklin, Wake, Chatham, Moore, Kichmond, and
Anson.
West of this line, which passes near Weldon, Raleigh and Rocking-
ham, we find the residual clays forming an almost universal mantle over
the surface. They are generally coarse-grained, red, brown or yellow
sticky clays, frequently of a lean character. Their thickness varies from
three to twenty or more feet, depending on the depth to which disinteg-
ration of the rock has taken place and the amount of erosion of the sur-
face that has occurred. In general, we may expect to find them of less
thickness on the steep slopes than on the gentler ones or level areas.
It not unfrequently happens that the clay has been little disturbed,
and the banded structure of the gneiss or schist from which it originated
may still be seen extending upward into the clay. As quartz decom-
poses more slowly than most rock-forming minerals, the veins of this
material are also to be seen at times traversing the clay.
Residual clays commonly contain many angular grains and frag-
ments of undecomposed or only partially decomposed mineral matter,
and the relative amount of this depends on the extent of the rotting of
the rock.
GEOLOGY AND GEOGRAPHY OF NORTH CAROLINA CLAY DEPOSITS. 45
The brickmakers are very prone to use these materials on account of
their sandy nature, their lean character making them much easier to work
by hand; at the same time their porous nature produces a porous, weak
brick unless properly burned, and at the smaller brickyards the burning
is seldom carried far enough.
The composition of two of these impure residual clays is given below :
Composition of Residual Clays.
Dean's Yard, Greensboro
Greensboro. Brk. & Tile Co.
Moisture 1.90 1.64
Silica 59.27 56.81
Alumina 22.31 20.62
Ferric oxide 6.69 6.13
Lime 25 .65
Magnesia 13 .58
Alkalies 90 4.47
Water (loss on ignition) 9.00 8.60
Total 100.45 99.50
Free sand 33.35 40.65
Fluxes 7.97 11.S3
The residual fire-clays found at Pomona and Grover are coarse-
grained, sandy clays of a semi-refractory nature, with much intermixed
quartz and mica. At times these two mineral impurities may become
so abundant that the portions of the vein holding them have to be
avoided in mining.
As these semi-refractory clay deposits have been but little worked
thus far, not very much can be said of their extent. Vein formations
such as they result from are often apt to be of a pocket-like nature, but
at times are very extensive, so that they should be well exploited before
much mining is done.
These residual clays are sometimes found such a short distance from
their point of origin that they still practically possess their residual
characteristics of leanness, coarseness, angularity of fragments, etc.
The kaolins, which also come under this head, are of the greatest
commercial value. They result from the decomposition of feldspar or
granite veins, so abundant in the crystalline area of ISTorth Carolina.
In width they vary from a few inches to 300 feet, and the kaolin
extends from the surface to a depth of 60 to 120 feet, depending on the
extent to which the feldspar has altered. Below this the fresh or par-
tially altered rock is met. In their unaltered state these vein.- may
serve as sources of feldspar or quartz, which, when of sufficient purity,
are available for potters' use.
The kaolin deposits at TTebster, N. C, have been worked for a num-
16 CLAY DEPOSITS IN NORTH CAROLINA.
ber of years to supply the potteries at Trenton, X. J., and East Liver-
pool, Ohio. The field work and laboratory tests carried on in con-
nection with the preparation of this report indicate additional ones of a
very promising nature.
SEDIMENTARY CLAYS.
The coastal plain deposits of North Carolina furnish the most exten-
sive beds of clay to be found within the State. They have been classed
as belonging to the Potomac (lower Cretaceous), Tertiary, and post-
Tertiary (Columbia) formations.1
The former are best exposed along the Cape Tear river below Eay-
etteville, and consist of dark-colored clays, at times very sandy and
frequently containing an abundance of organic matter.
The clay usually forms large lenses, and sometimes, by the increase
of sand, passes into sand beds. One of the best exposures of these
black Potomac clays is at Prospect Hall, 21 miles below Eayetteville;
but they are exposed also in many of the river bluffs from 10 to 60
miles below Eayetteville (p. 102).
The Eocene deposits are best exposed along the western border of the
coastal plain region in Moore and Harnett counties, lying near or at
the summits of the sand hills and ridges. Their thickness varies from
5 to 15 feet, or possibly more, and there usually is but little (2 to 6 feet)
of sandy overburden. The best known exposures of these are on the
Sprunt lands, 2 to 3 miles north of Spout Springs, and 2 miles southeast
of Southern Pines on the Seaboard Air Line Railway.
There are good exposures of clay in the cuts of the Cape Eear and
Yadkin Valley P. R. between Spout Springs and Eayetteville, the age
of which is not certain, though they are probably Eocene or Cretaceous.
The composition of these latter clays (see table at the end of report)
might lead one to assign a refractory character to them, but their
extreme fineness of grain causes them to fuse at comparatively low tem-
peratures. Their smoothness is marked, and they might be used for
other purposes.
Finely laminated clays of various colors are also to be found exposed
in railway cuts and river bluffs in many parts of the coastal plain
region, in some places associated with tertiary marls, and elsewhere
overlying them. Along the western border of the coastal plain region,
both in the river bluffs and on the divides between the streams, as are
to be seen at intervals along the Atlantic Coast Line R. R. from
Weldon to a few miles south of Eayetteville, are beds of finely laminated
clays varying in color from yellowish to nearly black, and often mot-
tled, which are believed to be a part of the Lafayette formation. None
1 J. A. Holmes. " The Kaolin and Clay Deposits of North Carolina," Trails. Amer. Inst. Min.
Eng. XXV, p. 929, 1896.
GEOLOGY AND GEOGRAPHY OF NORTH CAROLINA CLAY DEPOSITS. 47
of these clays has yet been fully tested, but the results of their exam-
ination will be described in a later report.
There is also to be found in the terraces bordering the larger streams
for some miles above and below where they pass from the hill country
into the coastal plain region, a series of red and brown loams, which,
near Weldon, Goldsboro and Fayetteville, in North Carolina, and at' as
many points similarly located in other Southern States, have been found
to make good brick when properly manipulated. These " brick loams,"
as they have been designated, are of still more recent origin than the
laminated Lafayette clays mentioned above, and they are classed with
the youngest of our extensive geological formations, that known as the
Columbia.
Many of the rivers farther inland, as they pass across the hill country,
and even in the mountain region, are often bordered by considerable
stretches of terrace which are underlain by brick or pottery clays, often
of excellent quality.
, The more sandy clays under these terraces are generally to be found
close to the river, while the finer grained and smoother ones have been
deposited nearer shore at the edge of the terrace, and when there are
several terraces they are usually found under the upper one.
Such terraces are abundant along the Catawba river near Morgan-
ton and Mount Holly; along the Yadkin river, especially at Wilkes-
boro and Elkin; along the Clarke river (south fork of Catawba river)
at Lincolnton, where clay to supply some fifty potters is dug.
It is from these terrace deposits of recent geologic age that some of
the best clays in the State are to be obtained. In depth they vary from
five to ten feet, and as some of these river valleys supply the lines of
railroad with an easy passage through the mountain regions, the clays
are well located for shipment either in their burned or unburned con-
dition.
These river clays are also well developed along the French Broad
river near Asheville; and( at Biltmore they have produced excellent and
extremely encouraging results.
It not uncommonly happens that the river terrace is formed on the
slope of some hill covered by coarse-grained, lean, residual clays, and
by the gradual creep of the soil the residual material moves down on to
the sedimentary clay underlying the terrace. Such conditions are not
uncommon, and at first sight the section of this kind exposed in a clay
bank presents a rather peculiar appearance.
As mentioned above, the sedimentary clays are also well developed
around Wilson, Goldsboro and Fayetteville.
With proper treatment, as will be mentioned later, these clays are
capable of excellent results, and yet by careless methods the product
that is sometimes produced is not fit to use.
48 CLAY DEPOSITS IN NORTH CAROLINA.
Just as much care should be taken in the manufacture' of brick as in
white ware. There is, unfortunately, too much disposition to regard
a brick as so many cubic inches of burned clay that must be able to
stick together and little more.
The omnipresence of residual brick clays in the South has had an
injurious effect on the clay-working industry, for when a large cotton
mill or other building is erected the contractor generally digs up the
nearest residual clay soil, the most siliceous he can find, and even then
sand is sometimes added to it to permit its mixing with the minimum
amount of labor.
This clayey sand is then molded by hand and hurriedly burned in
small scove kilns. The great amount of sand naturally tends to make
a porous brick, and burning the kiln barely to incipient fusion, and
never much beyond, prevents the clay from reaching its maximum
shrinkage. The result is a porous, soft brick.
The sedimentary clays generally make a smoother, denser brick, and
one which burns at a lower temperature, but the residual brick clays are
frequently capable of good results if properly handled.
Clays for making good common and pressed brick are of as much
importance in North Carolina as stoneware clays and kaolins, for prac-
tically all the pressed brick now used in the State are shipped from other
States.
THE NORTH CAROLINA CLAY-WORKING INDUSTRY.
The products at present manufactured in North Carolina include
stoneware, earthenware, fire-brick, sewer-pipe, flue-linings, drain-tile
and building brick.
Stoneware is manufactured by a number of small potters located
chiefly in the western part of the State. The clays used burn to a dense
hard body at moderate temperature, 2100° F., but the ware has a rough
surface aue to the glazing material, which contains much grit. The
same potters make red earthenware articles to a limited extent. "With
the available clays there is room for much improvement in the character
of the ware.
Fire-brick are manufactured at Pomona, Guilford county, Emma,
Buncombe county, and Grover, Cleveland county. In each case the
clays are coarse-grained, sandy ones, with much quartz and mica.
Those at Grover especially would probably make a very good grade of
refractory material, but their application has thus far been limited.
Sewer-pipe and flue-linings are only made at Pomona, Guilford
county, but the factory located at that place is turning out a very good
product, and it has recently been much enlarged.
Common brick are manufactured at many localities throughout the
GEOLOGY AND GEOGRAPHY OF NORTH CAROLINA CLAY DEPOSITS. 49
State, but pressed brick have not passed beyond the experimental stage;
although many of the clays are admirably adapted for this purpose, as
those near Asheville, Buncombe county, at Wilkesboro, Wilkes county,
around Goldsboro, Wayne county, and Raleigh, Wake county.
Many of these towns are at the intersection of several lines of railroad,
so that the product could be easily shipped.
In visiting the various localities for the collection of samples for
analysis and physical tests, this point has been borne in mind, and the
areas most accessible have been especially examined.
CHAPTER V.
KAOLINS OR CHINA CLAYS.
CHARACTER, MINING, PREPARATION POR MARKET.
North. Carolina is one of the important producers of kaolin used by
the manufacturers of white granite, C. C. (cream-colored) ware, and
porcelain, at Trenton, East Liverpool and other localities in the United
States, and the material produced stands second to none thus far mined
in this country.
All of the North Carolina kaolins thus far discovered are of a resid-
ual nature, that is, the material is found at the point where it originated.
They have resulted from the decay of veins of pure feldspar, pegmatite
or granite, and vary in their initial impurity according to the number of
foreign minerals which occurred in the vein from which they were
formed.
DISTRIBUTION OF THE KAOLINS.
Knowing thus the nature of their origin, it is possible to predict
approximately the limits within which they can occur. As the feld-
spar and granite veins are generally found cutting the gneisses,
granites or hornblende and mica schists, the kaolin deposits can occur
in any part of the central or western parts of the State, this being the
area underlain by the crystalline rocks. Large deposits have thus far
been recorded from Montgomery, Richmond, Cleveland, Burke, Jack-
son, and Macon counties.
MINEKALOGICAL CHARACTER OF KAOLIN.
The kaolin from most of these veins is a white, dense, soapy sub-
stance, soft and easily picked out. Through this may be scattered scales
of mica, garnet, quartz, etc. The mica is generally fresh in appearance
unless it is an iron-bearing species. The garnet is almost invariably
decomposed and forms rusty stains which can generally be eliminated
in washing. The quartz is practically always undecomposed and in
angular fragments. Its condition determines the necessity of its sepa-
ration; that is to say, if the quartz were- extremely fine its presence
would be harmless. If the vein was originally a coarsely crystalline
mass of quartz and feldspar, the former remains in such large fragments
that it is necessary to eliminate it by washing; but if the quartz and
KAOLINS OK CHINA CLAYS. 51
feldspar were intimately associated in a finely granular mixture, then
the quartz may be scattered through the kaolin in the form of a fine
siliceous powder, and if there are no other impurities with it, the quartz
can be left in the kaolin.
Indeed, it sometimes happens that there is so much finely divided
quartz present that it is impossible to separate all of it by washing.
This is the case with the kaolin from Troy.
Depending, therefore, on the character of the quartz, the washed
kaolin from different localities may show a very variable amount of
clay substances.
In the case of the Webster kaolin the quartz forms a large mass in
the centre of the vein, and is left standing while the kaolin is mined
away on either side.
In Plate V, facing page 59, fig. 2 shows a bed of residual clay near
Grover, and fig. 1 an extensive vein of residual kaolin near Webster.
PKOPERTIES OF KAOLIN.
Kaolin of good quality is pure white when washed and dried, but
often gray when wet. The purest North Carolina kaolin, and also other
American kaolins, show on microscopic examination bunched and also
isolated scales of kaolinite, plates and scales of white mica, grains of
quartz, and apparently feldspar grains.
The plasticity of kaolin is usually very lean, although some crude
kaolins are appreciably plastic to the feel. The tensile strength is always
low, and in the North Carolina kaolins varies on the average from 5 to
20 lbs. per square inch. Most kaolins absorb considerable water in
being worked into a plastic paste. They burn to a white body when
little iron is present, and the hardness and density vary with the degree
of temperature to which they are subjected, and also with the amount
of quartz and feldspar which they contain. In the manufacture of china
the kaolin is mixed with ball clay to give the mass plasticity, and feld-
spar to act as a flux. Quartz is also added to prevent excessive shrink-
age. It is in this connection that the value of a rational analysis is felt.
The rational analysis considers a clay as being made up of quartz,
feldspar, and kaolinite or clay substance, and shows the amount of each
present in the clay. If now the potter changes from the kaolin lie bas
been using to one from another locality, it will be possible for him, if he
has a rational analysis of this new clay, to determine without endless
experimenting how to vary the amount of quartz and feldspar whic
adds to his mixture in order to produce one which, with the new ka< lin,
will give as good results as the old one.
The method of rationally analyzing clays is discussed under the
"Chemical Analysis of Clay " (pp. 29-33), but a few points regardii g it
52 CLAY DEPOSITS IN NORTH CAROLINA.
may also be stated here. Clays may agree in their ultimate chemical
composition, but disagree widely in their rational composition. Clays
showing the same rational composition, will, other things being equal,
usually have the same shrinkage. If they differ in the degree of fine-
ness of their particles, they may show a different shrinkage, even though
they analyze alike rationally. In porcelain and white earthenware
manufacture the clay is generally ground so fine that this last point
does not have to be considered.
A rational analysis has been made of the kaolins of Xorth Carolina.
The fact that a kaolin does not contain 98$ of clay substance need not
cause the slightest uneasiness. The important requirement is a very low
percentage of iron. If in addition to clay substance the clay contains
quartz and feldspar, then just so much less quartz and feldspar will have
to be added in making up the porcelain or other mixture. The cele-
brated French kaolins which do not have to be washed sometimes con-
tain 38^ feldspar.1
An examination of the following table shows that there is consider-
able variation in the proportion of clay substance, quartz and feldspar
present.
Table showing variation in clay substance, quartz and feldspar.
Percentage of clay substance, quartz, and feldspar in North Carolina kaolins.
Clay
Locality. substance. Quartz. Feldspar.
Sylva (washed), N. Ca. Min. & Mfg. Co. (57) 94.21 5.75
Webster (washed), Harris Clay Co. (53)... . 96.81 0.07 3.12
(unwashed), G. Springer (54) 66.14 15.61 18.91
(washed), G. Springer (56) 93.24 ■ 6.60
Bostick Mills (unwashed) (21) 49.30 41.50 9.20
(22) 36.05 62.33
« (washed) (20) 54.30 43.85 1.S2
Troy, darker kaolin (64a) 14.71 83.94 1.91
(64) (washed) 20.83 76.20 2.34
" white kaolin (68) " 58.92 35.27 5.81
Wests Mill, Macon Co., crude kaolin (69)... 83.39 14.98 1.58
It will be seen from the above that the free sand or insoluble residue
in the North Carolina kaolins is nearly all quartz.
The variations in the total percentages of the washed samples is as
follows :
Variation in composition of kaolin, ivashed samples.
Silica 44.08 to S6.03$
Alumina 6.46 « 41.70
Ferric oxide 2S " 2. 97
Lime 15 " .50
Magnesia 09 " .20
Alkalies 25 « 2.4S
Water (loss on ignition) m 2.90 " 13.56
1 Seger's Ges. Schrift, p. 552.
KAOLINS OR CHINA CLAYS. 53
The special point of interest in these analyses is the iron percentage.
The per cent, of iron in the various washed kaolins and their color on
burning are as follows :
Table showing per cent, of ferric oxide in washed kaolin, and color on burning.
Ferric oxide, Color of
Locality. percentage. burned clay.
( .28
G. Springer, Webster " & 1 08 F O White.
Wests Mill 1.18 White.
Harris Clay Co., Webster 1.41 White.
Sylva 1.86 White.
( White, faint
Bostick Mills 2.14 \ .. '
( yellow tinge.
Dark kaolin, Troy 2.18 Light buff.
White kaolin, Troy 2.97 Red buff.
This affords an interesting series from which to determine the permis-
sible limit of iron in a kaolin. It would seem from this that the extreme
safety limit is 2$, but still under 1.5$ is more desirable. It should be
remembered that there might be 2 or 3$ of ferric oxide without its pres-
ence being noticed, provided there was also present 6 to 9$ of lime to
bleach it. But still it is undesirable to have to count on this, and even
if this condition existed the kaolin would burn yellowish white and not
pure white.
MINING OF KAOLIN.
Kaolin is usually soft enough to be mined with a pick and shovel.
If the kaolin deposit is large and broad, it can be worked as an open
pit, digging out the material with picks and shovels and loading it into
wheelbarrows or cars, which are drawn or pushed to the washing
troughs, or, if the pit is deep, brought to the foot of an incline and then
hauled up by means of a cable.
Most of the North Carolina kaolin deposits are vein formations whose
depth is comparatively great as related to their width. In such in-
stances the method of sinking pits is adopted. This consists in sinking
a circular pit in the kaolin about 25 feet in diameter. As the pit pro-
ceeds in depth it is lined with a cribwork of wood, as shown in fig. 2
of Plate III, which will be found facing page 56. This lining is ex-
tended to the full depth of the pit, which varies from 50 to 100 or even
120 feet. When the bottom of the kaolin has been reached the filling-
in of the pit is begun, the cribwork being removed from the bottom up-
wards as the filling proceeds. If there is any overburden it is generally
a good plan to use this for filling in the pits.
As soon as one pit is filled a new one may be sunk in the same manner
right next to it. In this ,way the whole vein is worked out, and, if the
54 CLAY DEPOSITS IN NORTH CAROLINA.
deposit is large, several pits may be sunk at the same time to increase
the output of the mine.
The kaolin is taken from the pit in buckets, which are operated by a
derrick. At the mouth of the pit it is discharged into barrows or cars.
Two other methods of mining may be mentioned.
If the deposit is deep and narrow, and the better portions of the kaolin
are irregularly scattered through the vein, it may be cheaper to sink
a shaft and run levels from this into the better parts of the bed. These
levels generally have to be timbered and the shaft also requires lining.
Hydraulic mining has been tried with success in some very sandy,
loose-grained kaolins, but is not used in Xorth Carolina. The method
as sometimes used consists in washing the clay down into the bottom
of the pit, whence it is sucked up by means of a pump and discharged
from the conveying pipe into the washing trough.
It is sometimes necessary to have a scraper to stir or loosen up the
clay in order to permit its being sucked up more easily. Where appli-
cable, this is a cheap and rapid method, but most kaolins are too dense
and not sandy enough to permit its being used.
At the Harris Clay Company's mines, near "Webster, the mines are
at a higher level than the washing plant, and the kaolin, after being
trammed for a few hundred feet from the mouth of the pits, is dis-
charged directly into a trough leading down the slope to the washing
works. A current of water is pumped up the slope and discharged into
the trough to wash the kaolin down.
A kaolin bed to be of commercial value should not be less than 8 feet
thick.
The workable depth depends on the distance below the surface to
which the feldspar has kaolinized.
PREPARATION OF KAOLIN FOR MARKET.
Most kaolins are washed before shipment. This is done to eliminate
coarse particles and substances such as iron, which would render the
clay fusible or discolor it in burning.
Two methods of washing may be used. The first consists in throw-
ing the kaolin into large circular tubs or " blungers " filled with
water; in these tubs there revolve arms which stir the mass up to a
mixture of creamy consistency. By this treatment the fine kaolinite
particles and some very fine quartz, feldspar and mica grains remain in
suspension while the coarser particles drop to the bottom. The water,
with the kaolin in suspension, is then drawn off to the settling tanks.
A modification of this consists in the use of a large cylinder, closed at
both ends. The cylinder is set in a horizontal position and contains an
axis with iron arms, which as the axis revolves serve to break up the
KAOLINS OK CHINA CLAYS. 0 0
•clay. The latter is charged through a hopper, and a current of water
passes into the end of the cylinder, while at the other end the water
passes out with the fine clay particles in suspension, the coarser ones
remaining in the cylinder.
The amount of water used has to be regulated by experiment. If an
excess is used, too much coarse material will be washed out of the cylin-
der, and conversely if the current is too slow, the clay will not yield a
sufficient percentage of washed material. The coarse sand remains in
the cylinder and has to be removed from time to time, depending on the
capacity of the cylinder and amount of coarse sand in the clay. \Vhen
the water and suspended clay leave the machine they are conducted to
the settling tanks.
This method is little used in this country for the purification of the
crude material, although it is extensively used abroad.
The prevalent method of washing kaolin in the United States is by
means of troughs, and the details of this method are as follows:
As the kaolin comes from the mine it is generally discharged into a
log-washer. This consists of a semi-cylindrical trough, in which there
revolves a horizontal axis bearing short arms. The action of these arms
breaks up the kaolin more or less thoroughly, depending on its density,
.and facilitates the subsequent washing. The stream of water directed
into the log-washer sweeps the kaolin and most of the sand into the
washing troughs, which latter are about 15 inches wide and 12 inches
•deep. They may be wider and deeper if the kaolin is very sandy;
in fact, they should be. The troughing is about 700 feet long, and to
utilize the space thoroughly it is broken up into sections (50 feet each
is a good length), these being arranged parallel, and connecting at the
ends, so that the water, with suspended clay, follows a zig-zag course.
This trough has a slight pitch in the North Carolina plants, being about
one inch in 20 feet, but this is a matter depending on the kaolin. If
the kaolin is very fine and settles slowly, the pitch need not be so great,
.and vice versa. A large quantity of very coarse sand in the kaolin is
a nuisance, as it clogs up the log-washer and upper end of the trough
more quickly, and causes so much more labor to keep them clear. As
it is, considerable sand settles there, and, to keep the trough clear, sand
wheels are used. These are wooden wheels bearing a number of iron
scoops on their periphery. As the wheel revolves these scoops catch up
a portion of the sand which has settled in the trough, and as each scoop
reaches the upper limit of its turn on the wheel, it, by its inverted posi-
tion, drops the sand outside of the trough. These sand wheels are a
help, but it is very often necessary to keep a man in addition shoveling
the sand from the trough.
A general view of the kaolin-washing plant at the Harris kaolin mine
56 CLAY DEPOSITS IN NORTH CAROLINA.
near Webster is shown in Plate III, fig. 1. At the end of the shed
on the right are the four sand wheels. Xext to these conies the trough-
ing, while in the lowest part of the illustration in front of the house are
the settling tanks. In the background along the foot of the hill are
the drying racks.
If the sand is finer it is not dropped so quickly, but distributed more
evenly along the trough and does not clog it up so fast.
The zig-zag arrangement of the troughing has been objected to by
some, as it produces irregularities in the current, causing the sand to
bank up in the corners at the bends, and also at certain points along the
sides of the troughing.1
The effect of this is to narrow the channel, and consequently increase
the velocity of the current, thereby causing the fine sand to be carried
still further towards the settling tanks.
This difficulty, which is not often a serious one, has been obviated
either by having the troughing straight, or by allowing the water and
suspended clay as it comes from the logwasher to pass through a section
of straight trough, and from this into another one of the same depth but
five or six times the width and divided by several longitudinal partitions.
The water and clay then pass into a third section, twice as wide as the
second, and divided by twice the number of longitudinal divisions.
By this means the water moves always in a straight course, but as it
is being continually spread out over a wider space it flows with an ever
decreasing velocity.
By the time the water has reached the end of the troughing nearly
all of the coarse grains have been dropped and the water is ready to be
led into the settling vats, but as a further and necessary precaution the
water is discharged onto a screen of 100 meshes to the linear inch.
The object of this is to remove any coarse particles that might possibly
remain, and also to remove sticks and other bits of floating dirt that
are sure to be introduced.
Two kinds of screens can be used: 1, stationary, and 2, revolving.
The stationary screen is simply a frame covered with 100-mesh copper
cloth and set at a slight angle. The water and suspended kaolin fall
on this and pass through. If they do not they run off the screen and
are lost.
A slight improvement is to have two or three screens overlapping,
so that whatever does get through the first will fall on the second.
If the vegetable matter and sticks are allowed to accumulate they
clog the screen up and nothing will run through. These stationary
screens therefore have to be closely watched.
The revolving screens are far better, for they keep themselves clean.
1 E. Hotop. Thonindustrie Zeitung, 1893.
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE III.
FIG. 1.- KAOLIN WASHING AND DRYING PLANT, HARRIS CLAY CO., NEAR WEBSTER.
(See also page 61.)
m
FIG. 2.— KAOLIN MINE, HARRIS CLAY CO., NEAR WEBSTER.
Showing method of sinking pits in the soft kaolin. (See pages 53 and 60.'
KAOLINS OB CHINA CLAYS.
57
Such a screen is barrel-shaped, and the water, with the kaolin in sus-
pension, is discharged into the interior and passes outward through the
screening. As the screen revolves, the dirt caught is carried upwards
and finally drops; but instead of dropping down upon the other side of
the screen, it falls upon a board which diverts it out on to the ground.
Fig. 1. — Pump used in forcing kaolin suspended in watek from the
settling vats into the pkesses.
The settling tanks into which the kaolin and water are discharged
may be, and often are, about 8 feet wide by 4 feet deep and 50 feet or
more long. As soon as one is filled the water is diverted into another.
The larger a settling tank, the longer it will take to till it and allow
the kaolin to settle, and delays due to this cause are expensive, especi-
ally when the market takes the output of washed kaolin as soon as it is
ready. Too many small tanks increase the initial cost of plant.
5S CLAY DEPOSITS EST NORTH CAROLINA.
If the kaolin settles too slowly, alum is sometimes added to the water
to hasten the deposition. When the kaolin has settled most of the
clear water is drawn off, and the cream-like mass of kaolin and water in
the bottom of the vat is drawn off into the slip pumps and forced by them
into the presses. Figure 1, on the preceding page, shows a form of
pump used for this purpose, made by the Turner, Vaughn and Taylor
Company of Cuyahoga Falls, Ohio.
The presses consist simply of a series of flat iron or wooden frames
between which are flat canvas bags. These bags are connected by
nipples with the supply tube from the slip pumps. By means of the
pressure from the pumps nearly all of the water is forced out of the
kaolin and through the canvas.
"When all the water possible is squeezed out the pressure is removed,
the press opened, and the sheets of semi-dry kaolin taken out. These
sheets are rolled up and put on the racks out in the open air or in a
steam-heated room to dry.
Plate IY, fig. 1, shows a kaolin filter press with wooden frame,
and fg. 2, such a press with an iron frame. The latter is preferable,
especially in climates where wood decays easily.
In a plant of steady and moderate capacity, both economy and ease
may be practised by paying a little attention to its proper arrangement.
It is a good idea to have cars on a track, or an endless belt run past
the presses and drying racks. The clay can then be taken right from
the presses and put on the cars or belt and taken right from them and
put on the racks.
As for every ton of crude kaolin usually only about two-fifths or
sometimes one-quarter of a ton of washed kaolin is obtained, the impor-
tance of having the washing plant at the mines will be easily seen, for
it avoids the hauling of 60 to 70$ of useless sand, which has to be washed
out before the kaolin can be used or even placed on the market.
DEPOSITS OF KAOLIN IN NORTH CAROLINA.
KAOLIN IN JACKSON COUNTY.
Near Sylva. — North Carolina Mining and Manufacturine; Co. The
kaolin mine of this company is two miles south of Sylva on the mountain
slope. The wall rock is a gneiss, now largely decomposed to a ferru-
ginous clay. The kaolin vein cuts this, striking about N. 15° E. Its
exact width is not known, but it is 8 to 10 feet in places. A 50-foot shaft
has been sunk on the vein, and from the foot drifts have been run in
both directions along the vein. This drift is about 4 feet wide and
6 feet high. That running to the east from the shaft is about 150
feet long, including two offsets due to faulting of 16 feet each. The
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE IV.
FIG. 1.— WOODEN FRAME FILTER-PRESS- FOR REMOVING THE WATER FROM THE WASHED KAOLIN.
FIG. 2.— IRON FRAME FILTER-PRESS, FOR REMOVING THE WATER FROM THE WASHED KAOLIN.
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE V.
FIG. 1.— RESIDUAL KAOLIN DEPOSIT, HARRIS CLAY CO., WEBSTER.
View looking N. E. along the strike, shows only half of the vein, the rock on the left being a large lens
of quartz in the center of the vein.
FIG. 2 —RESIDUAL CLAY DEPOSIT, NEAR GROVER.
Belonging to the Powhatan Clay Manufacturing Company. 'See page 82.)
KAOLINS OK CHINA CLAYS. 59
drift running west has gone only a short distance. A second tunnel
was started towards the east, about 8 feet above the bottom of the
shaft.
There are streaks of so-called " sand " at several points in the mine,
which are patches of only partially kaolinized rock. Several tons of
fresh feldspar have been shipped from this mine. The washed clay is
very fine-grained with no grit. Color pure white. Very smooth.
Slakes slowly but very completely. To produce a workable paste 40$
of water was required. This paste was lean, and shrunk 8fc in drying
and 4cr/o in burning, giving a total shrinkage of 12$. The tensile strength
of air-dried briquettes made from this paste was 15 lbs. per square inch.
Incipient fusion occurs at 2200° ¥., vitrification at 2450° F., and vis-
cosity at 2700° F.
The clay burns to a pure white, smooth body.
The shrinkage in drying and burning is 3$ less than in the case of
the kaolins from Florida.1
The following is the analysis of this clay:
Analysis of washed kaolin (No. 57) N. C. Mining & Mfg. Co., two miles south of Sylva.
Moisture 3.07
Silica (total) 44.08
Alumina 36.26
Ferric oxide 1.S6
Lime 43
Magnesia 20
Alkalies 50
Water (loss on ignition) 13.56
Total 99.96
Free sand 5.75
Total fluxes 2.99
From this analysis we get:
Clay substance 94.21
Quartz and feldspar 5.75
Specific gravity 2.31
The insoluble residue was not analyzed separately, as there was such
a small amount of it.
From the analysis it will be seen that the clay contains a high per-
centage of clay substance.
Near "Webster. — Harris Clay Company. The kaolin deposit of this
company is a large and very coarse pegmatite vein or dike with a max-
imum thickness of nearly 300 feet. In the middle there is a large
thick lens of quartz. (Plate V, fig. 1.)
1 Langenbeck, Chemistry of Pottery, 101.
60 CLAY DEPOSITS IN NORTH CAROLINA.
The vein runs almost north and south, and the kaolin is of high
quality, but has some quartz and mica, and occasionally garnet mixed
in with it.
The wall rock is a reddish, fine-grained, much decomposed gneiss,
and the boundary between the kaolin and gneiss is not always sharp.
There are really three distinct " veins " of kaolin included in the 300
feet mentioned above. A tunnel was driven across a portion of the
deposit from west to east, and the materials which were passed through,
together with their thickness, were as follows:
Section across the Harris Kaolin Mine near Webster.
Kaolin 28 ft.
Gneiss 23 "
Quartz 32 "
Kaolin (exposed in V tunnel) 56 "
Kaolin (bored through) 21 "
Kaolin (exposed in shaft) 22 "
182 ft.
The 21 feet exposed in boring were through kaolin, and ended in a
shaft 22 feet wide sunk in the eastern half of the vein. There were
several feet of kaolin beyond this shaft, giving over 100 feet of solid
kaolin in the eastern half of the vein. The tunnel was about 70 feet
below the surface.
The pits sunk in the kaolin vary from 15-25 feet in width and 80-100
feet in depth. The deepest thus far sunk is 125 feet through solid
kaolin. (Plate III, fig. 2, p. 56.)
Since April, 1896, the company has been following the strike of the
vein down the hill, toward the north, and has sunk several new pits in
this direction.
The washed kaolin from this mine is smooth to the taste and feeling
and shows little or no grit. In water it falls slowly but completely to
a fine powder. Forty-two per cent, of water were required to give a
workable paste, which was somewhat lean. It shrunk 6# in drying
and 4z/c in burning, giving a total shrinkage of 10$. The average ten-
sile strength of air-dried briquettes was 20 lbs. per square inch with a
maximum of 22 lbs. Incipient fusion occurred at 2300° F.3 vitrifica-
tion at 2500° F., and viscosity above 2700° F.
The clay burns to a white body. The ultimate and rational analysis
of this kaolin yielded the following results:
KAOLINS OR CHINA CLAYS. 61
Analysis of Kaolin {No. 53), Harris Clay Co.'s Mine, Webster.
Washed kaolin. Portion insoluble.
Moisture 35 ....
Silica 45.70 2.00
Alumina 40.61 0.55
Ferric oxide 1.39 0.27
Lime 0.45 ....
Magnesia 0.09
Alkalies 2.82 0.37
Water (loss on ignition) 8.98 ....
Total 100.39 3.19
Free sand 3.19
Total fluxes 4.75 ....
Specific gravity 2.43
This gives the following :
Clay substance 96.81
Quartz 0.07
Feldspar 3.12
100.00
The kaolin as mined is discharged into the upper end of a trough,
along which it is washed down to the works. It is discharged into the
upper end of the washing troughs, and, with the water, passes along
under 5 sand wheels, which extract a large amount of the fine sand and
keep the trough from becoming clogged. The kaolin, sand and water
then pass along 700 feet of troughing, gradually dropping the sand,
until the settling tanks are reached. There are 3 troughs, 4 pumps
and 4 presses, open-air drying racks, and a steam-drying room. The
capacity of the works is 24 tons per day of washed and dried kaolin.
(See Plate III, p. 56.)
The washed kaolin has to be hauled four miles to the railroad at Dills-
boro. The clay is dried in the steam chamber in three days, while on
the racks it requires two weeks.
Springer Clay Pit. — Geo. Springer, Jr., has recently opened a mine
of kaolin on the property of AVm. Buchanan, one-half mile northeast of
Webster. A drift has been run in from the side of the hill and across
the vein. In this tunnel the vein of kaolin shows up 25 feet wide and
strikes K 15° W.
Two headings have been run north and south from the drift for a
distance of five feet. About 50 tons of the crude material have been
thus far taken out.
The kaolin appears to be of excellent quality, but the presence of
some coarse angular quartz fragments necessitates it> washing.
Both the crude and washed clays were tested, and the two series of
tests are given in parallel columns for the sake of comparison. Xo. 54
is the crude material and Xo. 56 the washed kaolin.
62 CLAY DEPOSITS IN NORTH CAROLINA.
Physical tests of Kaolin, washed and crude, Springer pit.
Xo. 54. No. 56.
Crude kaolin. Washed kaoliD.
f Coarse to fine. Very fine.
Character ( gandy Sm00th_
Slaking Fast and complete. Slow and complete.
Water required to give paste 32% 38%
Plasticity Lean. Lean.
Air shrinkage 2 8
Fire shrinkage 4 4.5
Average tensile strength 6 lbs. 23
Maximum tensile strength 7 lbs. 24
Condition when burned Porous. Dense.
Color when burned White. White.
Incipient fusion 230(T F. 2350'- F.
Vitrification (incomplete) 2500° F. 2550c F.
Viscosity above 2700° F. above 2700° F.
Analysis of Kaolin, Springer pit, }i mile X. E. of Webster.
No. 54* Xo. 56.
Crude Insoluble Washed Insoluble
kaolin. residue. kaolin. residue.
Moisture 25 2.05
Silica 62.40 29.12 45.78 6.60
Alumina 26.51 3.S5 36.46
Ferric oxide 1.14 .65 .28
Ferrous oxide 1.08
Lime 57 .50
Magnesia 01 .04
Alkalies 9S .90 .25
Water (loss on ignition) . . 8.S0 13.40
Total .100.66 34.52 99.S4
Fluxes 2.70 2.15
Specific gravity 2.58 2.27
From the rational analysis we tet the following :
Clay substance 66.14 93.24
Quartz 15.61)
Feldspar 1S.91 / b,bU
It is plain that the effect of the washing has been to eliminate the
percentage of quartz and feldspar and relatively increase the clay sub-
stance nearly 30$. Of the fluxes only the alkalies have been decreased.
KAOLIN IN MACON COUNTY.
Xear "Wests Mill. — On the land of Geo. Brindel, near "Wests
Mill, is a deposit of kaolin of remarkable whiteness, which burns to a
* Composition of Clay substance of 54:
Silica 50.50 Alumina 34.24 Ferric oxide 0 74
Lime 0.36 Magnesia 0.01 Alkalies 0. 10
AVater 13 35
KAOLINS OR CHINA CLAYS. 63
pure white color, showing its excellent quality. It is very line-grained,
free from grit, and shows a few scattered white mica scales. It slakes
slowly but thoroughly.
The addition of 31$ of water gave a workable paste of the usual lean
character. The bricks made from this paste shrunk 6$ in drying and
6$ in burning, giving a total shrinkage of 12$. The air-dried bri-
quettes had an average tensile strength of 15 lbs. per square inch and
a maximum of 18 lbs. Incipient fusion occurs at 2300° F., vitrifica-
tion at 2600° F., and viscosity at over 2700° F. The clay burns to a
pure white body.
The following analysis of the unwashed sample shows its remarkable
purity:
Analysis of Kaolin (Wo. 09) from Geo. BrindeVs land, near Wests Mill.
Crude kaolin. Insoluble residue.
Silica (total) 53.10 15.23
Alumina 33.06 0.07
Ferric oxide 1.18 0.46
Lime 0.38
Magnesia 0.0S ....
Alkalies 0.S3 0.S0
Water (loss ou ignition) 11.32 ....
Total 99.95 16.56
Total fluxes 2.47
Specific gravity 2.31
From the above we get :
Clay substance S3.39
Quartz 14.9S
Feldspar 1.5S
Subtracting the second column from the first, we get the composition
of the clay substance, which, in the second of the two following col-
umns, is recalculated to 100. The clay substance, it will be seen, is
nearly pure kaolinite, but with a slightly greater amount of alumina
in proportion to the silica than is called for by the formula of kaolinite:
Composition of Clay Substance in Kaolin from Wests Mill.
Silica 37.87 15.4]
Alumina 32.99 39.51 i
Ferric cxide 0.72 0.St>
Lime 0.3S 0.45
Magnesia 0.0S 0.09
Alkalies 0.03 «'.,.:;
Water (loss on ignition) 11.32 L3.5S
83.39 99.98
64 CLAY DEPOSITS IN NOKTH CAROLINA.
KAOLIN IN MONTGOMERY COUNTY.
Eeae Teoy. — Considerable quantities of kaolin have recently been
discovered 4 miles west of Troy, Montgomery county.
From the various outcrops two samples were tested.
The first sample forwarded (No. 64) was a darker kaolin. This was
a fine-grained, gritty clay, which passes almost entirely through a 60-
mesh sieve. It slakes easily and quickly to fine grains.
The sample when washed yielded a residue of 40$, which is probably
somewhat larger than would be obtained in actual practice, and this
washed kaolin required 30$ of water to produce a workable paste that
was lean to the feeling. This paste shrunk 3$ in drying and an addi-
tional 10 '$ in burning, giving a total shrinkage of 13$. The average
tensile strength of air-dried briquettes was 9 lbs. per square inch with
a maximum of 12 lbs. per square inch. Incipient fusion occurred at
2100° F., vitrification at 2300° F., and viscosity at 2500° F.
The clay burns to a very pale buff.
The second sample forwarded was a white kaolin (No. 68) and does
not possess the grayish tint which the other does. It shrank 3$ in dry-
ing and 9$ in burning, giving a total shrinkage of 12$. The air-dried
briquettes had an average tensile strength of 10 lbs. per square inch
with a maximum of 12 lbs. Incipient fusion occurs at 2100° F., vitri-
fication at 2300° F., and viscosity at 2500° F. The kaolin burns to a
deeper buff than the preceding one.
The coloration of these two kaolins is against their use for white-
ware, but they might be used for higher grades of stoneware, encaustic
tiles, or in the body of refractory wares for laboratory use.
The crude white kaolin was at first tested, as its snow-white color
suggested that it might burn white and to a dense body without further
treatment. The results obtained were so similar to those of the washed
white kaolin that they are simply given in the appended table. The
tensile strength of the crude material was a few pounds greater and the
shrinkage in burning three per cent. less.
An examination of the following analyses indicates the rather high
iron percentage which accounts for the color of the burned clay. A
comparison of the analysis of the washed and crude kaolin also points
out that the percentage of sand has been reduced, but none of the iron
removed.
In the following analyses ~No. 64a represents the darker kaolin (crude)
from 4 miles west of Troy, ~Ro. 64 this darker kaolin washed, and No.
68 the white kaolin washed from the same localitv.
j
KAOLINS OR CHINA CLAYS. 65
Analyses of Kaolin 4 miles W. of Troy, Montgomery Go.
No. 64a. No. 64. No. 68.
Moisture 48 .53 .75
Silica 90.13 86.03 63.10
Alumina 4.99 6.46 23.33
Ferric oxide 1.86 2.14 2.97
Lime 13 .17 .15
Magnesia 01 .04 .09
Alkalies 1.03 1.00 1.90
Water (loss on ignition) .... 1.93 2.90 7.65
Total 100.56 99.27 99.94
Insol. residue 85.85 78.54 41.08
Total fluxes 3.03 3.35 5.11
Specific gravity 2.47 2.32 2.34
Analyses of insoluble residue from the above.
No. 64a. No. 64. No. 68.
Silica 84.64 77.25 38.25
Alumina 20 .30 .85
Ferric oxide 37 .26 .46
Alkalies 64 .73 1.52
85.85 78.54 41.08
From the above, by a rational analysis, we get the percentages of the
mineral ingredients as follows:
Mineral Composition of Kaolin 4 miles W. of Troy, N. C.
No. 64a. No. 64. No. 68.
Clay substance 14.71 20.83 58.92
Quartz 83.94 76.20 35.27
Feldspar 1.91 2.34 5.81
Composition of the clay substance in the above.
No. 61a. No. 64.
Silica 38.58 43.46
Alumina 33.66 30.04
Ferric oxide 10.46 9.30
Lime 91 .84
Magnesia 07 .19
Alkalies 2.70 1.33
Water (lost on ignition) 13.56 14.35
99.94 99.51
KAOLIN IN RICHMOND COUNTY.
Near Bostick. — Considerable residual kaolin has recently been
found on the property of Robert W. Steele, near Bosticks Mills, 14
miles north of Rockingham, Richmond county. A number of tesl
pits have been sunk and the exploitations indicate the presence of an
5
66 CLAY DEPOSITS IN NORTH CAROLINA.
abundant amount of material. The deposit could be readily trans-
ported to market. It is two miles from the end of a lumber railroad,
and after hauling to this point the lumber company would transport it
to the railroad at Hoffman, a distance of 12 miles, for not exceeding
50 cents a ton; or this timber railroad could be extended easily and
cheaply to the kaolin deposit.
The first point at which the kaolin appears is one mile south of Bost-
ick P. O and near Christopher Bostick's cabin, where it crops out for
a distance of fifty feet in a ditch by the roadside. It is next seen
on the opposite side of the road, at base of hill, but between these two
exposures is a red clay resulting from the decomposition of schistose
rock.
Just east of the first-mentioned exposure, and in the woods about 100
feet from the road, a test pit four feet square has been sunk (No. 21).
This showed lj feet overburden and then 3 feet kaolin. The pit had
been sunk 10 feet through kaolin, but had caved in. About 30 feet
from this another pit was sunk to a depth of 12 feet. This also shows
the kaolin from one foot below the surface down to the bottom (No. 20).
Several other small pits have been sunk within a radius of 75 feet, and
all penetrated the kaolin. The material is fine-grained, with compara-
tively few angular fragments. There are scattered stains of iron, but
these may disappear with depth.
Another series of pits (No. 22) have been sunk on Mr. Chapel's land,
one mile due west of No. 21. These pits were sunk to a depth of 10
feet, and the kaolin appeared at 18 inches from the surface and con-
tinued to bottom of pits. This kaolin is whiter than that at 21. Be-
tween the two deposits there is a shallow valley, and it is not known
whether 21 and 22 are portions of one vein or not.
Samples of Nos. 20, 21 and 22 were tested in their crude condition,
and Nos. 20 and 22 were also washed.
No. 20 is a fine-grained kaolin with little coarse grit, which slakes
slowly but completely to a fine-grained mass. It required 27.7$ of
water to give a workable paste, which shrank 4$ in drying and 9$ in
burning. Incipient fusion occurs at 2250° F., vitrification at 2500' F.,
and viscosity at 2700° F. The average tensile strength of air-dried
briquettes was 10 lbs. per square inch with a maximum of 14 lbs. per
square inch. The clay burned to a dense body with slightly yellowish
tint.
No. 21 slaked the same as 20. It required 26$ of water to make a
workable but lean paste, which shrunk 3.5$ in drying and 8# in burn-
ing. Incipient fusion occurred at 2300° F., vitrification at 2500° F.,
and viscosity at 2700° F. The clay burns to same tint as No. 20. Its
average tensile strength was 13 lbs. per square inch, with a maximum
of 16 lbs. per square inch.
KAOLINS OR CHINA CLAYS. 67
~No. 22 is a somewhat porous, fine-grained white clay with compara-
tively little grit, which slakes slowly but completely to fine grains.
It required 27.7$ of water to make a workable but lean paste. This
paste shrunk 4=fc in drying and an additional 8$ in burning. The aver-
age tensile strength of the air-dried briquettes was 15 lbs. per square
inch with a maximum of 16 lbs.
Incipient fusion occurs at 2250° F., vitrification at 2450° F., and vis-
cosity at over 2700° F.
The following analyses of these three samples (crude kaolin) were
made:
Analyses of Kaolin near Bosticks Mills, 14 miles ~N. of Rockingham, Richmond Co.
No. 21. No. 20.* No. 22.
Crude Insol. in Crude Insol. in Crude Insol. in
Kaolin. H2S04 etc. Kaolin. H2S04 etc. Kaolin. H2S04 etc.
Silica 68.15 47.45 70.63 48.10 73.70 62.33
Alumina 19.99 1.70 21.81 3.24 16.03
Ferric oxide 1.86 .20 1.49 .56 1.57
Lime 13 .20 .38
Magnesia 16 .29 .47
1 Na20 .72 ")
Alkalies 2.85 1.35 1.45 I ._ " nA y 1.90
J K2G .24 J
Moisture 17 .... .08 .... .... ....
Water (loss on ignition). 4.70 4.04 4.33 ....
Total 98.01 50.70 99.99 52.S6 98.38 62*33
Total fluxes 5.00 3.43 4.32
Specific gravity 2.52 2.41 2.43
From the above we obtain the mineralogical composition of the
kaolins as being:
Mineral composition of Kaolin near Bosticks Mills.
No. 21. No. 20. Mo. 22.
Clay substance 49.30 47.14 36.05
Feldspar 9.20 ) 16.13
S
Quartz .41.50/ 36.^°
A 5 -lb. sample of No. 20 was washed. The settlings amounted to
4r.Ofc7 which is probably somewhat larger than would be obtained in
actual practice. The washed kaolin required 26$ of water to give a
workable paste that was lean but smooth. This paste shrunk 3$ in
* Composition of Clay Substance of No. 20:
Silica —
47.88
did 04
Ferric oxide ...
1.90
Lime
0.42
0.80
Alkalies
l.di
Water
a 50
99.46
68 CLAY DEPOSITS IN NORTH CAROLINA.
drying, and there was an additional shrinkage of 9$ in burning. In-
cipient fusion occurred at 2250° F., vitrification at 2450 J F., and
viscosity at over 2700° F. There was a faint yellowish tint to the
burned ware.
Sample ~No. 22 was also washed. The washed material was 35^ of
the original mass. It required 29$ to give a lean but workable paste
that shrunk 4$ in drying and 7$ in burning, giving a total shrinkage
of life The air-dried briquettes had an average tensile strength of
8 lbs. per square inch and a maximum of 11 lbs. Incipient fusion
occurs at 2250° F., vitrification at 2450° F., and viscosity at over 2700°
F. The clay when washed was pure white, but when burned had the
faintest yellow tint.
An analysis was made of the washings from 'No. 20 and yielded the
following percentages :
Analysis of Washings from Kaolin (No. 20), near Bosticks Mills.
Total portion. Insoluble portion.
Silica ...., 71.12 44.38
Alumina 19.61
Ferric oxide 2.18
Lime 17
Magnesia 08
Alkalies 2.48
Water (loss on ignition) 4.33
Total 99.97 45.67
From the above we get the following:
Mineral composition of washings from the Bostick Kaolin No. 20.
Clay substance 54.30
Quartz 43.85
Feldspar 1.82
Composition of clay substance from the Bostick Kaolin, sample No. 20.
Silica 49.33
Alumina 35.90
Ferric oxide 3.15
Lime 31
Magnesia 14
Alkalies 3.15
Water (loss on ignition) S.00
Total 99.98
USES OF THE NORTH CAROLINA KAOLINS.
The foregoing tests of the kaolins from several localities are to be
looked upon as very promising, for they indicate the presence of much
material of a high grade.
KAOLINS OR CHINA CLAYS. 69
It would be possible' to make comparisons of the North Carolina
kaolins with those from other localities, but such comparisons have
little practical value, unless the chemical and physical characters of
each clay are known. Many ultimate and rational analyses of foreign
kaolins have been published, but few physical tests are given.1
As a matter of interest, some of the North Carolina kaolins may be
compared with celebrated foreign ones which are used in the manu-
facture of the highest grades of porcelain.
In the following columns the analyses, No. a (53) and No. b, are
those of washed kaolin from the mine of the Harris Clay Co., the first
analyzed by Chas. Baskerville, the second by C. Langenbeck.2 Number
c is an analysis of the well-known kaolin from Zettlitz, near Carlsbad,
in Bohemia.
Analyses of Kaolins : Webster, N. C. (a and b) and Zettlitz (c).
Nos. a (53). No. T>. No. c.
Silica . 45.70 45.80 46.82
Alumina 40.61 39.20 38.49
Water (loss on ignition) 8.98 13.11 12.86
Ferric oxide 1.39 .40 1.09
Lime 45 .45 ....
Magnesia 09 .15 tr.
Alkalies 2.82 .92 1.40
100.04 100.03 100.66
The washed white kaolin from 4 miles west of Troy, N. C. (No. 68),
is interesting to compare with a German kaolin from Sennewitz, near
Halle, (d) and which is used at Berlin for the manufacture of porcelain.3
The two are very similar in their ultimate composition, but disagree
strongly when their rational analyses are compared.
Analyses of Kaolin from Troy, JV. G. (68) and Sennewitz, Germany (d).
No. 68. No. d.
Moisture 75 ....
Silica 63.10 64.87
Alumina 23.33 23.83
Water (loss on ignition) 7.65 8.36
Ferric oxide 2.97 .83
Lime 15 ....
Magnesia 09 .50
Alkalies 1.90 1.39
99.94 99.7S
Clay substance 5S.92 63.77
Quartz 35.27 35.50
Feldspar 5.81 .73
1 ThoDindustrie Zeitung, 1893, p. 1311. -Chemistry of Pottery. 3Sefr. Ges. Sohr., p. 50.
70 CLAY DEPOSITS IN NORTH CAROLINA.
The North Carolina kaolins, which contain under one per cent, of
ferric oxide, are perfectly well adapted to the manufacture not only of
white earthenware, but also of the best grades of porcelain. Those
with 1-J to 2$ of ferric oxide could no doubt be used for lower grades
of white earthenware, while those containing 2 to 2^ of ferric oxide
might be utilized for mixing with fire-clays in the manufacture of
refractory apparatus.
Kaolin containing very little grit, which would be the case when it
had a very large percentage of clay substance, is eagerly sought after
by paper manufacturers. Kaolin is also used in the manufacture of
ultramarine. For this purpose it should be as low in iron and lime
as possible. An excess of silica is undesirable, but if too little is
present it may be added in the form of finely powdered quartz.
31
CHAPTEE VI.
POTTERY CLAYS IN NORTH CAROLINA.
THE POTTERY INDUSTRY.
The pottery industry of North Carolina has thus far been confined
entirely to small potteries of perhaps 25,000 gallons annual capacity,
whose trade is mostly local. There are between forty and fifty of these
small potteries in the state, and most of them are located near Jugtown
and Blackburn in Catawba county, and Henry in Lincoln county.
There are others scattered over the state, as at Wilkesboro, Wilkes
county, two miles north of Morganton, Burke county, and several
other localities.
All of the potteries in Lincoln and Catawba counties obtain a large
amount of their clay from the lowlands along the Clarke river (south
fork of Catawba) two miles north of Lincolnton, some of them having
to haul it 14 miles. They pay 50 cents a ton for it, and generally haul
the. clay on their return from a peddling trip, when their wagons would
otherwise be empty.
The clays used for pottery purposes in North Carolina are the finer
aluminous sediments underlying the river terraces to be found in many
of the broader valleys, and the better ones are generally found near the
shore line of the terrace. These terrace deposits of fine-grained, plastic
clay are common, and with an increasing demand for pottery clays
in the state, an abundance of the necessary material will probably be
found close at hand.
In addition to the clay deposits underlying the terraces along Clarke
river, especially north of Lincolnton, which have already been men-
tioned, the Catawba river, which flows by Morganton and Catawba,
and thence southward past Mt. Holly, has also a marked terrace devel-
opment; and the clays north of Morganton have already been used for
pottery manufacture.
A third series of deposits of terrace clays is to be found along the
Yadkin river.
Those at "Wilkesboro emphasize the importance of making a rather
thorough search for the proper kind of clay, for the material found
there at one point is only suitable for brick, while one-quarter of a mile
further it is eminently plastic, smooth, and burns to a dense hard body,
just such as is needed for stoneware.
72 CLAY DEPOSITS IN NORTH CAROLINA.
REQUISITES OF A POTTERY CLAY.
This term is meant to include the lower grades of earthenware and
stoneware clay. For common earthenware, such as flower-pots, almost
any red-burning, plastic clay will suffice, if it permits turning on the
potter's wheel and burns to a good red but not vitrified body.
It is also possible to make a very serviceable grade of earthenware
from calcareous clays, with up to 20 or 30 per cent, of calcium car-
bonate (provided it is finely divided and evenly distributed through the
clay), and cover the ware with an easily fusible glaze of clay, clay and
lead, or a mixture of fusible compounds. The majolica wares made in
Italy and Germany are made from such clays.
Stoneware clays require a little more attention.
They should possess good plasticity in order to permit molding or
turning without cracking.
Their tensile strength should be preferably not less than 125 lbs. or
150 lbs. per square inch.
They should not shrink excessively in burning, and should burn to a
dense vitrified body at a temperature of 2000° F. or 2100° F. if pos-
sible. The lower temperature of vitrification is of course an important
item of economy. For the same reasons the clay should permit of rapid
drying. It should also be smooth and as free from grit as possible.
The fluxing impurities in a stoneware clay should be sufficiently high
to produce a vitrified body. Iron is a desirable coloring ingredient.
Lime, if in small amounts, 2-3$, is not very objectionable, but a large
percentage may bleach the iron color, decrease the shrinkage and in-
crease the fusibility. Calcium sulphate is undesirable, for its dissocia-
tion at high temperatures may cause blistering.
It is frequently found that better results can be obtained by
mixing two different clays, the one furnishing stiffness and low shrink-
age, the other plasticity and easier fusibility. This is done by all of
the North Carolina potters, the two clays which they use being mixed
in equal proportions, although in their case the chief difference of the
clays used is in plasticity and stiffness.
Clays for making yellow ware are generally low grade fire-clays
which burn to a buff color. They are usually washed to eliminate any
coarse sand and pyrite nodules which they may contain. This is gen-
erally done in a circular vat or " blunger," in which there revolve
stirrers, as mentioned under " The Preparation of Kaolin " (page 54).
Yellow ware is first molded and burned to incipient fusion, the trans-
parent or opaque glaze applied and the ware burned again.
Some of the shale clays associated with the coal seams in North
Carolina might answer for this purpose, but they have not yet been
tested.
POTTERY CLAYS IN NORTH CAROLINA. 73
STONEWARE MANUFACTURE.
The methods at present employed within the State are somewhat
crude, but best adapted, perhaps, to the size of the plant and available
capital.
The clay is mixed in a vertical box, in which there is set a shaft with
iron cross-pieces. This shaft is turned by horse-power, and the clay
becomes mixed by the action of the iron arms. Before molding, the
clay is further wedged. It is tempered to quite a soft paste, whose
total shrinkage in drying and burning is 20-25^, according to the potters.
The molding is done on the old-fashioned " kick-wheel," and the green
ware dried on shelves set over a long, low, hot-air flue in the centre of
the room.
The wares are burned in a long, low kiln resembling a muffle in
form. The glaze is either old glass or furnace slag ground fine and
applied in the form of a slip. The glass is put on the wares set in the
upper end of the kiln, as it melts easier, while the ware set in the lower
end of the kiln is coated with the ground slag.
If a pottery clay possesses all the requisite chemical and physical
characters but is gritty, it is often possible to remove the grit by wash-
ing. This is best done in a circular tub in which there revolve stirring
arms, as mentioned under the head of kaolin washing. The water, with
suspended clay, is drawn off and the latter allowed to settle in tanks.
The clear water is then drawn off and the clay can be dried by steam
or in the sun. Sandy clays will dry quicker, but they do not burn to
as dense a body.
None of the North Carolina potters use Albany slip for glazing their
ware. If they did the product would be far more sightly than it is
now. The crude glaze which they use is cheap, but it cracks very
soon. "With a little experimenting of the proper nature it would be
possible to find glazes adaptable to the clays now being used. This,
together with the application of improved methods and some care,
would enable the North Carolina potter to put a far better grade of
ware on the market, and sell it at a correspondingly increased price.
At present nearly all of the earthenware and stoneware used in the
larger towns and cities of North Carolina comes from other states.
The molding is all done by hand, and in the present state of the
industry plaster molds have not been deemed necessary.
As has been already stated, many of these river clays are well adapted
to stoneware manufacture, and would give a far better product than is
now being made. Their temperature of vitrification is also high enough
to bear the application of Albany slip as a glazing material.
The Albany slip is an impure fusible clay found in the Eudson river
valley in New York state. It vitrifies at ls<><> F. and forms a brown,
74
CLAY DEPOSITS IN NORTH CAROLINA.
evenly colored coat. No other clay has yet been found which has these
qualities of such constancy.
In larger stoneware factories the kick-wheel is found insufficient.
For the ordinary symmetrical shapes a common potter's wheel can be
used, operated by steam power. Crocks, jugs and similar articles are
molded on this, the potter throwing a lump of clay on the revolving
wheel and then deftly working it up into the desired form simply by
using his fingers.
Fig. 2. — The Potters' Jolly Wheel, No. 8.
Many articles are molded on a jolly wheel. With this a plaster of
Paris mold is used to form the article. The mold is set on the wheel
and, while being revolved, a lump of the tempered clay is thrown into
it and worked out in a thin layer over the interior surface of the mold.
POTTERY CLAYS IN NORTH CAROLINA. 75
The mold is then set aside to dry, and the clay shrinks from the mold
and hardens sufficiently to be lifted out. Fig. 2 shows a jolly made
by the Turner, Vaughn & Taylor Co., of Cuyahoga Falls, Ohio.
The speed of drying depends on the clay. If possible, the drying is
done in a steam-heated room for a number of hours until the ware is
dry enough to be burned. If slip glaze is used the ware has to be
first dipped into it and once more dried before burning, but if salt glaze
is used the ware is put directly in the kiln.
The quicker the drying and burning which a clay will permit with-
out cracking the more economical it is to use it.
Very plastic clays have to be dried slowly to prevent cracking, but
this difficulty may be overcome by the admixture of more sandy ones.
Burning may be done in circular kilns, which are either up-draft or
down-draft in their action. The burning and cooling take from 5-8
days, depending on the clay.
The water-smoking can generally be carried on rapidly, but the cool-
ing should not be hurried, to avoid cracking.
POTTERY INDUSTRY IN BURKE COUNTY.
Near Morganton. — Three miles north of Morganton is the North
Carolina pottery, at present inoperative, but the plant is one of the
largest in the State. The clay which it is claimed was alone used is
on Manly McDowell's property, li miles west of Morganton and along
the road, an eighth of a mile from the Catawba river.
This clay (No. 51) directly underlies the terrace surface and is a fine-
grained, gritty, soft clay, overlain by 18 inches to 2 feet of yellow loam.
The bed of clay is 6-7 feet thick.
The addition of 36$ of water gave a stiff, somewhat smooth, but
rather lean mass, which shrunk 9.6$ in drying and -1.5;/ in burning,
giving a total shrinkage of 14.1$.
The air-dried briquettes of this clay had an average tensile strength
of 60 lbs. per square inch with a maximum of 81 lbs.
Incipient fusion occurs at 1950° F., vitrification at 2100° F., and
viscosity at 2250° F. The clay burns red.
The analysis of the clay is as follows:
Analysis of Pottery Clay [No. 51), Manly McDowell's, near Morganton.
Moisture 1.68
Silica (total) 69.58
Alumina 14.03
Ferric oxide 6.4 1
Lime 40
Magnesia 27
Alkalies 1.65
76 CLAY DEPOSITS IN NORTH CAROLINA.
Water (loss on ignition) 5.73
Total 99.75
Clay substance 45.47
Free sand 54.28
Total fluxes 8.73
Specific gravity 2.59
It is manifestly impossible that pottery could have been made from
this clay alone, on account of its low binding power, and a more plastic
material must have been mixed with it.
POTTERY INDUSTRY IN CATAWBA COUNTY.
Near Blackburn. — Many of the potters, especially those at Black-
burn, use a highly plastic, dark-colored clay obtained two miles north-
west of Blackburn on the property of M. Finger. This clay is smooth,
dense, and slakes slowly to irregular, scaly flakes. There is a noticeable
amount of organic matter present in it.
The addition of 30^ of water was required to give a workable mud,
which was very plastic. This paste shrunk 12$ in drying and an addi-
tional 7fo in burning, giving a total shrinkage of 19$. The briquettes
made from this clay had when air-dried an average tensile strength of
148 lbs. per square inch and a maximum of 200 lbs. Incipient fusion
occurred at 1950° F., vitrification at 2100° F., and viscosity at 2250° F.
The clay burns to a grayish brown body of good density.
The analysis of the clay is as follows:
Analysis of Pottery Clay (No. 50), 2 miles JJT, W. of Blackburn.
Moisture 2.08
Silica (total) 50.17
Alumina 28.77
Ferric oxide 2.88
Lime 05
Magnesia 22
Alkalies 1.04
Water (loss on ignition) 14.03
Total 99.24
Clay substance 73.19
Free sand 26.05
Total fluxes 4.19
Specific gravity 2.35
The high percentage of loss on ignition is due to the several per cent,
of organic matter in the clay. This also increases the plasticity and
adds somewhat to the air shrinkage.
POTTERY CLAYS IN NORTH CAROLINA. 7 <
POTTERY INDUSTRY IN LINCOLN COUNTY.
Near Lincolnton. — The clay along the Clarke river, northwest and
north of Lincolnton, supplies nearly fifty potters in Catawba and Lin-
coln counties.
The material is a fine-grained gray clay with occasional yellow iron
stains. Two samples were tested, No. 61 from the pits at end of lane
on T. Rhodes' property two miles northwest of Lincolnton, and No. 49
from about one-quarter mile farther up the river.
No. 61 is a fine, gritty clay with scattered mica scales. It slakes
slowly. The addition of 35$ of water gave a smooth, very plastic mass
which shrunk 10$ in drying and 7$ in burning, giving a total shrinkage
of life The air-dried briquettes of this clay had an average tensile
strength of 157 lbs. per square inch and a maximum of 1S6 lbs.
Incipient fusion occurs at 1900° F., vitrification at 2100° F., and
viscosity at 2300° F.
The clay burns to a dark red body.
This clay is not as plastic as that obtained northwest of Blackburn,
nor is its tensile strength always so great, as will be seen from the tests
of the next sample, but it is a good material for common stoneware.
The analysis of the clay is as follows :
Analysis of Pottery Clay {No. 61), T. Rhodes' land, 2 miles N. W. of Lincolnton.
Moisture 2.10
Silica (total) 57.20
Alumina 24.82
Ferric oxide 3.25
Ferrous oxide 1.42
Lime 73
Magnesia 13
Alkalies 93
Water (loss on ignition) 8.25
Total 98.83
Clay substance 02.27
Free sand 36.57
Total fluxes 0.40
Specific gravity 2.51
Sample ~No. 49 from the pits on T. Rhodes' property is finely gritty
clay which slakes slowly but completely. It required the addition of
40$ of water to make a workable paste, which was very plastic to the
feel. This paste shrunk 9.5$ in drying and 5.5$ in burning, giving a
total shrinkage of 15$. The air-dried briquettes made from tlii- mud
had an average tensile strength of 133 lbs. per square inch and a max-
imum of 158 lbs.
78 CLAY DEPOSITS IX XOBTH CAEOLIXA.
Incipient fusion occurred at 1900° F., vitrification at 2100° F., and
viscosity at 2300° F.
The clay burns reddish white at 1900° F. and deep red at 2100° F.
The composition of it is as follows :
Analysis of Pottery Clay {No. 49), Rhodes' land, 2£ miles N. W. of Lincolnton.
Moisture 69
Silica (total) 57.08
Alumina 26.11
Ferric oxide 4.64
Lime 20
Magnesia 16
Alkalies 1.42
Water (loss on ignition) 8.52
Total 9S.82
Clay substance 62.76
Free sand 35.96
Total fluxes 6.42
Specific gravity 2.53
POTTERY INDUSTRY IX WILKES COUNTY.
Near vYilkesboeo. — At the west end of the village of Wilkesboro a
small pottery has used the clay outcropping at the fork of the roads,
and also drawn upon an additional bed in a field to the north.
That dug along the road is a light bluish-white clav. tough, and con-
taining small amounts of fine grit. This is used to furnish stiffness to
the potter's mixture, while that from the field across the road furnishes a
bond in burning.
The stiff clay (Xo. 34) is fine-grained and contains little mica. It
slaked slowly and required the addition of 40$ of water to make a work-
able paste, which was slightly plastic. This shrunk 7.5$ in dry-
ing and 12$ in burning, giving a total shrinkage of 19.5$. The air-
dried briquettes had an average tensile strength of 51 lbs. per square
inch and a maximum tensile strength of 63 lbs. per square inch.
Incipient fusion occurred at 1900° F., vitrification at 2050° F., and
viscosity at 2200° F. The clay burns red and dense. Its composition
is as follows:
Analysis of Pottery Clay {No. 34), near Wilkesboro.
Moisture 1.28
Silica (total) 54.38
Alumina 27.27
Ferric oxide 5.48
Lime 45
Magnesia 41
POTTERY CLAYS IN NORTH CAROLINA. 79
Alkalies 68
Water (loss on ignition) 9.78
Total 99.73
Clay substance 75.73
Free sand 24.00
Total fluxes 7.02
Specific gravity 2.37
To the north of this locality one-half mile and underlying the broad,
low river terrace along the Yadkin river, is a large deposit of clay on
the land of Calvin Cowles. A deep trench has been run across the
property, exposing the clay throughout its length, and samples were
taken from this point.
It is a fine-grained, smooth, dark-colored clay, containing very little
grit. It slakes slowly to grains and granules. 35 $ of water were
required to give a workable mixture, which was very plastic. This
paste shrunk 10$ in drying and 5$ in burning, giving a total shrinkage
of 15$. The air-dried briquettes had an average tensile strength of 169
lbs, per square inch, and the maximum tensile strength amounted to
192 lbs. per square inch. Incipient fusion occurred at 1800° F., vitri-
fication at 2000° F., and viscosity at 2200° F.
The clay burns to a hard, dense, brownish-gray impervious body at
2000° F., and should make an excellent potter's clay. It required slow
drying and heating to avoid cracking. The composition of it is as
follows :
Analysis of Pottery Clay {No. 35), ]/2 mile north of Wilkesooro, C. Cowles' land.
Moisture 2.20
Silica (total) 54.24
Alumina 24.97
Ferric oxide 4.83
Lime 57
Magnesia 70
Alkalies 2.52
Water (loss on ignition) 9.-40
Total 99.43
Clay substance 67.0S
Free sand 32.35
Total fluxes 8.62
Specific gravity 2.-40
This is not unlike the clay at the pottery, but its finer grain, greater
percentage of alkalies, make it burn dense at a lower heat.
CHAPTER VII.
FIRE-CLAYS AND PIPE-CLAYS IN NORTH CAROLINA.
FIRE-CLAYS.
The fire-clay deposits of North Carolina are few in number as thus
far known. They are either residual deposits or the wash from them.
There are a number of siliceous clays in the State which at a moderate
temperature burn to a cream-white or white color, and the bricks made
from these clays are used for bakers' ovens and boiler foundations.
They are called fire-brick, but are not such in the true sense of the word.
Refractory clays occur at Pomona, Guilford county, and Grover,
Cleveland county, and are mined at both places.
While it is desirable that fire-clays should possess good plasticity and
low shrinkage, the main point is the refractory character. A good
fire-clay should be unaffected by 2500° F., but many good clays will
not stand this degree of heat, nor is it required for the uses to which
they are to be put. In general, it may be said that the fusible impuri-
ties of a fire-clay should not exceed 3J or 4 per cent, if it is fine-grained,
or even less if it is very fine-grained, but if coarse-grained they may
reach even 5$. The clay on the railroad near Spout Springs, for
example, has only 3.81$ of total fluxes, yet on account of its very fine
grain it is by no means refractory. If a fire-clay shrinks too much in
burning this may be often counteracted by the addition of "grog,"
viz., sand, ground fire-brick or other substances which would dilute the
shrinkage. Fire-clays which are fat and plastic generally burn to a
dense body, but crack considerably owing to their high shrinkage.
This may be counteracted best by mixing burned clay of the same or
some other kind with the fresh material. This burned clay or grog,
should be burned as dense as possible before use. Fine-grained or pow-
dered grog permits the brick to shrink more in burning than coarse-
grained, and bricks with the latter generally stand changes of tem-
perature better. Next to burned clay, quartz is the most important
grog.
If a fire-brick made only of clay and clay-grog still shrinks when
placed in the furnace, sharp quartz grains should be added, as they have
a tendency to expand on repeated heatings. Fine-grained quartz sand
should in no case be added as it tends to act as a flux in burning. The
addition of coarse quartz must also be within limits, for if too large it
loosens the stone by expansion.
FIRE-CLAYS AND PIPE-CLAYS IN NORTH CAROLINA. 81
A good fire-brick is sometimes made by mixing a non-plastic refrac-
tory clay with a very plastic, dense burning semi-refractory one.
Fire-brick are now mostly molded by hand and repressed. For a
time many manufacturers molded their bricks in stiff mud or even dry-
press machines, but most of them have returned to the old method.
FIRE-CLAYS IN CLEVELAND COUNTY.
Near Grover. — Surrounding the village of Grover is an extensive
series of outcrops of a light bluish-gray sandy clay of variable depth
and nature. In some pits it shows its residual character beyond a
doubt, but at other points, if of residual origin, it appears to have
been sorted over and compacted by water action. Two companies have
mined this clay, the Grover Brick Company and the Powhatan Clay
Manufacturing Company of Richmond, Ya.
The former company has one pit in a hollow along a stream three
quarters of a mile due S. W. of Grover station. The upper three feet
are loam with lumps of red clay, and under this come 6 feet of bluish-
white sandy clay (No. 43). The Grover Brick Company make their
white fire-brick from this.
A sample of this (No. 43) shows it to be a gritty, fine to coarse,
dense, tough clay, with abundant coarse quartz grains. It slakes slowly
to irregular grains and scales.
The addition of 32^ of water gave a workable mass of moderate plas-
ticity. This paste shrunk 10.6^ in drying and 6r/e in burning, giving a
total shrinkage of 16.6^. The average tensile strength of the air-dried
briquettes was 38 lbs. per square inch with a maximum of 42 lbs.
Incipient fusion occurs at 2100° F., vitrification at 2300° F., and vis-
cosity at 2500° F. The clay burns white at incipient fusion, but light
buff at higher temperature.
The white-burned brick made from this clay are sold as fire-brick.
The composition of the clay is as follows:
Analysis of Fire-clay {No. 43), Grover Brick Co.'s Eskridge pit.
Moisture ^6
Silica (total) (^--S
Alumina 1 8.83
Titanium oxide -'
Ferric oxide 2.60
Lime "°
Magnesia 13
Alkalies 2.29
Water (loss on ignition) 6.47
Total 100.33
6
82 CLAY DEPOSITS IN NORTH CAROLINA.
Clay substance 46.99
Free sand 53.30
Total fluxes 5.72
Specific gravity 2.57
About 500 feet IS". E. of the preceding is a second pit belonging to
the Powhatan Clay Manufacturing Company of Richmond, Va. It
is seven feet deep. They encountered the same bluish-white sandy
clay, and at the bottom of the excavation found considerable dense,
fine-grained plastic clay.
The bottom clay (No. 44) which they mine was sampled and tested
in order to determine its difference from the more sandy and commoner
clay. It is a very plastic clay and freer from grit than the other. It
slakes slowly and required the addition of 28^ of water to give a work-
able mud, which shrunk 8$ in drying and 5$ in burning, giving a total
shrinkage of 13//. The average tensile strength of the air-dried bri-
quettes was 39 lbs. per square inch with a maximum of 45 lbs.
Incipient fusion occurs at 2100° F., vitrification at 2300° T., and vis-
cosity at 2600° F. The clay burns to a yellowish-white body.
The analysis of the clay yielded as follows:
Analysis of Fire-clay (No. 44), Powhatan Clay Mfg. Co., S. W. of Grover.
Moisture 1.29
Silica (total) 53.07
Alumina 29.54
Ferric oxide 1.27
Ferrous oxide 1.00
Lime 0.15
Magnesia 0.14
Soda 0.S7
Potash 1.28
Water (loss on ignition) 9.93
Total 98.54
Clay substance 61.99
Free sand 36.55
Total fluxes 4.71
Specific gravity 2.24
The bricks made from this clay have the reputation of being free from
discoloration. This is due partly to the low iron percentage, and partly
to the fact that they are burned hard enough to oxidize the ferrous iron
and prevent its being brought to the surface of the brick afterwards in
solution and oxidized there to ferric oxide.
The brick have had an extended use in many of the eastern cities.
The clay (No. 45) in the other pit of the Powhatan Clay Manufac-
turing Company, one-half mile east of Grover (see Plate Y, fig. 2,
FIRE-CLAYS AND PIPE-CLAYS IN NORTH CAROLINA. 83
p. 59), is more like sample (44) from the pit of the Grover Brick
Company.
It is a mixture of fine and coarse white clay with abundant sand
grains and much mica. In water it slakes very slowly. Thirty-one
per cent, of water added to it gave a workable paste, which was lean
and gritty and shrunk 4^ in drying and 4.5$ in burning, giving a total
shrinkage t of 8.5$. The average tensile strength of the air-dried bri-
quettes was 31 lbs. per square inch with a maximum of 35 lbs. per
square inch.
Incipient fusion occurred at 2150° F., vitrification at 2350° F., and
viscosity at 2550° F. The clay burns to a yellowish-white.
Its composition is shown by the following analysis :
Analysis of Fire-clay (No. 45), Powhatan Clay Mfg. Co., yz mile E. of Grover.
Moisture 95
Silica (total) 64.13
Alumina 22.35
Ferric oxide 1.95
Lime 10
Magnesia 22
Alkaliesi Soda "
( Potash 1.81
Water (loss on ignition) 5.98
Total 98.48
Clay substance 46.88
Free sand 51.60
Fluxes 5.07
Specific gravity 2.51
There are two more openings in the same deposit a short distance
south of Grover. These clays around Grover are all good semi-refrac-
tory clays, and they make an excellent yellowish- white brick; but their
chief use up to the present time has been for the manufacture of light
brick. These are molded on stiff-mud. auger machines and repressed.
The pit from which the residual clay iSTo. 45 came is shown in fig. 2.
FIRE-CLAYS IN GUILFORD COUNTY.
Pomona Clay Bank. — The Pomona Terracotta Company has a
deposit of white, very sandy, coarse-grained clay on its property which
is used for the manufacture of fire-brick. Judging from the angular
grains in its substance, as well as the abundance of prominent mica
scales, it is probably a residual deposit which has been somewhat altered
by wash. It occurs on the south side of Xorth Buffalo creek and just
84 CLAY DEPOSITS IN NORTH CAROLINA.
east of the company's new factory. The available portion of it is three
feet thick, for it then changes into a very sandy clay which possesses
exceedingly low plasticity. The upper clay slakes very slowly to a
granular, gritty mass. It required 26$ of water to make a workable
paste out of it, and this was lean. This paste shrunk 10$ in drying and
2$ additional in burning, giving a total shrinkage of 12$. Air-dried
briquettes made from this paste had an average tensile strength of -17
lbs. per square inch and a maximum of 49 lbs. per square inch.
Incipient fusion occurs at 2150° F., vitrification at 2350° I\, and vis-
cosity at 2550° F.
The clay burns red or buff, depending on the intensity of firing and
oxidizing condition of the fire. Its chemical composition is as follows:
Analysis of Fire-clay {No. 25), Pomona Terracotta Works.
Moisture 9S
Silica (total) 70.45
Alumina 17.34
Ferric oxide 3.16
Ferrous oxide 33
Lime 25
Magnesia 22
Alkalies 70
Water (loss on ignition) 6.63
Total 100.06
Clay substance 48.26
Free sand 51.50
Fluxes 4.66
Specific gravity 2.55
The under clay (25a) is a very siliceous white clay that slakes slowly
and completely to irregular grains.
Thirty-three per cent, of water added to it gave a workable but very
lean mass which shrunk 3$ in drying and 3$ in burning, giving a total
shrinkage of 6$.
The average tensile strength of air-dried briquettes was 14 lbs. per
square inch with a maximum of 16 lbs. Incipient fusion occurred at
2200° F., vitrification at 2400° F., and viscosity at 2600° F. The clay
burns to a gray buff.
This clay is not used. Attempts have been made to mix it with the
sewer-pipe clay, but it would not take the salt glaze. The trouble is
probably similar to a case which Prof. E. Orton, Jr., cited to the writer
from Ohio, the difficulty lying in the extremely siliceous nature of the
clay, which does not possess enough alumina to unite with the silica
and salt to give the glaze, which is a silicate of aluminium and sodium.
The composition of this under fire clay is as follows:
FIRE-CLAYS AND PIPE-CLAYS IN NORTH CAROLINA. 85
Analysis of Clay (No. 25a), under the Fire-clay, Pomona Terracotta Works.
Moisture 1.17
Silica (total) 70.15
Alumina 15.51
Ferric oxide 3.34
Lime 83
Magnesia 07
Alkalies 3.75
Water (loss on ignition) 5.14
Total 09.96
Clay substance 39.46
Free sand 60.50
Total fluxes 7.99
There is probably much undecomposed feldspar in the clay, and while
the total fluxes are high, the grain is so coarse as to raise the fusing
point.
Woodroffe Clay Bank. — Tlios. Woodroffe, of Greensboro, has a
similar deposit of fire-clay about one mile north of the Pomona sewer-
pipe works and along the same creek. It is likewise a very gritty, tough,
dense, light gray clay, that slakes very slowly. Twenty-eight per cent,
of water was required to make a workable mixture. This shrunk 9.3$
in drying and 4^ in burning, giving a total shrinkage of 13.3/fc. Air-
dried briquettes of the mud had an average tensile strength of 51 lbs.
per square inch and a maximum of 56 lbs. per square inch. Incipient
fusion occurs at 2100° F., vitrification at 2300° F., and viscosity at
2500° F.
If burned reddish when heated to barely 2100° F., or in reducing fire
the clay remained white. This is the condition of the bricks manu-
factured from this fire-clay at Pomona, but if the clay is raised above
2100° F. and with an oxidizing lire the clay burns buff or red.
The composition of the clay from WoodronVs bank is shown by the
following:
Analysis of Fire-clay {No. 29), Woodroffe Bank.
Moisture 1.13
Silica (total) 71.60
Alumina 1 5.27
Ferric oxide •">••">•'>
Lime IT
Magnesia 21
Alkalies • -M -*
Water (loss on ignition) 5.40
Total 99.53
Clay substance 42.83
Free sand 56.70
Total fluxes 5.83
Specific gravity 2.60
86 CLAY DEPOSITS IN NORTH CAROLINA.
This closely approaches the Pomona Sewer-pipe and Brick Co.'s clay
in composition.
PIPE-CLAYS IN NORTH CAROLINA.
Clays which are suitable for the manufacture of sewer-pipe should
answer the following requirements:
They should be plastic to permit molding without cracking; they
should have a tensile strength of 125-150 lbs. The clay should burn
to a dense, hard, impervious body, of a red or deep red color. The dry-
ing should permit of rapidity, and the ware should not warp or crack
in doing so. The same may be said of the burning.
An excess of fluxing impurities may render a clay so fusible that in
burning it softens to such an extent as to lose its shape. It is a very
common practice therefore to use a mixture of clays, the one fusible to
form a bond in burning, the other much less so to preserve the shape
of the ware. This is done at Pomona, for example.
There should be a considerable but not excessive percentage of
silica in the clay for the salt vapors to unite with and form the glaze.
An excess of silica is detrimental, However, to the formation of a good
glaze, for the latter is a silicate of sodium and aluminium, and conse-
quently if there is an excess of silica and lack of alumina, a poor glaze,
or perhaps none at all, may form. This is probably the case with the
under fire-clay at Pomona, which for a while was mixed in with the
pipe-clay.
MANUFACTURE OF SEWER-PIPE AND TILE.
If shale or hard clay is used it has to be first ground in a dry pan,
but with soft clays they can be put directly into the wet pan or chaser
mill, which in a few minutes tempers each charge rapidly and thor-
oughly. (Plate YI, fig. 2.)
This method of tempering is far more thorough and quicker than a
pugmill, although requiring more power.
The tempered clay is generally taken to the upper story of the fac-
tory by means of bucket elevators and discharged into the clay cylinder
of the sewer-pipe press. (Pig. 3, p. 87, and Plate VI, fig. 1.)
The press (fig. 3, page 87) consists of two cylinders, an upper steam
and a lower clay cylinder, and the ratio of their diameters is generally
as 3 : 1. The clay cylinder is filled with clay, and the piston then forced
downwards by the piston of the steam cylinder above, the piston rod
of the two being continuous. This forces the clay out through the die
at the bottom. When the clay in the form of a pipe has issued to the
proper distance, the machine is stopped. If of small diameter the pipe
is sometimes simply broken off, but for large pipe and usually small
ones the pipe is cut off close to the mouth of the die either by means
of a wire or else by an automatic knife edge located within the die.
N. C. GEOLOGICAL SURVEY
BULLETIN 13, PLATE VI.
FIG. 1.— PRESS FOR SEWER-PIPE, TILE, AND HOLLOW BRICK.
FIG. 2— CHASER MILL FOR TEMPERING CLAY FOR SEWER-PIPE.
Yig. 3.— Vaughn Sewer-Pife Press, No. 7.
60 inch Steam Cylinder, 36 inch clay Cylinder.
88 CLAY DEPOSITS IN NORTH CAROLINA.
The edges of the pipe are trimmed and the pipe are then set on the
drying floor.
Small diameter pipe can be dried comparatively fast, but large ones
must be dried very slowly.
Sewer-pipe are usually burned in circular kilns of down-draft pat-
tern, which are from 16-25 ft. (rarely more) in diameter. The pipes
are set on top of each other, and when there are several sizes they are
nested. Figure 1 of Plate VII shows a circular down-draft kiln.
The burning can proceed quite rapidly on account of the thinness
of the ware. The salt is added to the fires when the temperature of
the kiln has reached its maximum.
Sewer-pipe should be free from blister, cracks and other defects.
They should also be straight.
Elbows and Y's are made by molding the clay in plaster molds, or
in the case of Y's and T's straight pieces of pipe are sometimes trim-
med to fit together in the desired shape, and the parts cemented by slip.
They have to be dried more slowly. Sewer-pipe are made from 2 to
2-J ft. in length, and in diameter from 3-30 inches.
GUILFORD COUNTY.
Pomona Terracotta Co.'s Works. — The Pomona Terracotta Com-
pany has its works and clay pits at Pomona, three miles west of Greens-
boro. The clays- occur in the bottom of the flat valley along both sides of
North Buffalo creek, and are practically of two kinds, a plastic pipe-
clay, and a white quartzose clay, called a fire-clay. The pipe-clay is
said to occur only on the north side of the creek and the fire-clay on
the south side. This is true for the sewer-pipe company's pits, and they
also claim it to hold true at other points above and below them on the
creek. There are four pits opened up in the pipe-clay. In the first,
or that nearest to the factory, there are five feet of dark clay, and two
feet of red. The material from this pit furnishes one-half of the sewer-
pipe mixture. That in the second pit is similar to the lower clay in the
first, but is said to shrink less in burning.
The upper red in the first pit (No. 27) is a lean, gritty clay, which
required the addition of 30$ of water to make a workable paste. In
water the clay slakes quickly to scaly fragments. The clay shrinks
10$ in drying and 6$ in burning, giving a total shrinkage of 16$. The
average tensile strength of the air-dried briquettes was 59 lbs. per
square inch, with a maximum of 67 lbs. per square inch. Incipient
fusion occurs at 2000° F., vitrification at 2150° F., and viscosity at
2300° F. The clay burns to a brownish red. Its composition is as fol-
lows :
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE VII.
£^
FIG. 1.— CIRCULAR DOWN-DRAFT KILN FOR TILE, &c.
5™ v.
jtJ$MLl
lUi I 1 m\ 1
W^^^^^^:
KB^^^^^^-1" *^
FiQ. 2.— TUNNE. DRYERS USED IN BRICK MAKING.
(See page 98.)
..1
FIRE-CLAYS AND PIPE-CLAYS IN NOETH CAROLINA. 81)
Analysis of upper Pipe-clay {No. 21), Pomona Terracotta Co.
Moisture 2.05
Silica (total) 54.28
Alumina 22.27
Ferric oxide 8.45
Ferrous oxide 1.33
Lime 45
Magnesia 18
Alkalies 60
Water (loss on ignition) 10.50
Total 100.11
Clay substance 67.57
Free sand 32.51
Fluxes 11.01
Specific gravity 2.50
The color of the fresh clay is evidently due to the high amount of
hydrated ferric oxide or limonite.
The under clay (No. 26) from this same pit is also a gritty clay, but
more plastic. It slakes slowly to scaly fragments. Forty per cent, of
water was required to make a workable mass, which shrunk 10$ in
drying and 6$ in burning, giving a total shrinkage of lQfc The air-
dried briquettes made from this material had an average tensile strength
of 86 lbs. per square inch and a maximum of 103 lbs. Incipient fusion
occurred at 2050° F., vitrification at 2250° F.? and viscosity at 2150° F.
The clay burns red. Its composition is shown by the following
analysis :
Analysis of under Pipe-clay {No. 26), Pomona Terracotta Co.
Moisture 1.53
Silica (total) 58.73
Alumina 23.94
Ferric oxide 3.71
Lime 05
Magnesia 09
Alkalies 1.25
Water (loss on ignition) 9.S0
Total 99.10
Clay substance 65.70
Free sand •*>•">. I"
Fluxes 5.1 ( >
Specific gravity 2.52
The clay in the second pit (No. 28) is a gray, gritty clay with numer-
ous quartz grains, tough, moderately fine-grained, ami -lake- slowl;
irregular granules.
v to
90 CLAY DEPOSITS IN NORTH CAROLINA.
It required the addition of 33^ of water to produce a workable mass,
which, however, was quite plastic, but did not feel as plastic as the
tensile strength would suggest it to be. This mixture shrunk 8$ in dry-
ing and 2>c/c in burning. The average tensile strength of the air-dried
briquettes was 145 lbs. per square inch, with a maximum of 160 lbs.
per square inch. Incipient fusion occurred at 2000° F., vitrification at
2200° F., and viscosity at 2400° F.
The clay analyzed as follows :
Analysis of Pipe-clay {No. 28), 2nd pit Pomona Terracotta Go.
Moisture 2.20
Silica (total) 70.75
Alumina 13.87
Ferric oxide 5.01
Lime 82
Magnesia 29
Alkalies 1.15
Water (loss on ignition) 5.00
Total 99.09
Clay substance 39.40
Free sand 59.70
Fluxes 7.27
Specific gravity 2.51
As these three clays serve different purposes in the manufacture of
the sewer-pipe, it may be well to compare them.
No. 26. Good plasticity.
No. 27. Gives a better red in burning, and vitrifies at lower tem-
perature.
^N"o. 28. Shrinks less and has better bonding qualities. The char-
acters are summed up in the following table :
Comparison of Pipe-clays, Pomona Terracotta Co.
No. of
the Tensile Temperature in F. Degrees.
Sam- Shrinkage. Strength. Incipient Vitri- Viscos-
ple. Feel. Drying. Burning. Av. Max. Fluxes. Fusion, fication. ity.
26 Plastic 10$ 6$ 86 103 5.10$ 2050° 2250° 2150°
27 Lean 10$ 6$ 59 67 11.07$ 2000° 2150° 2300°
28 Very plastic 8$ 3$ 145 160 7.27$ 2000° 2200° 2400°
The clay as it is mined is thrown into cars which are run to the foot
of an incline up which they are drawn by a cable to the factory. The
clay mixture is put through the usual chaser mill, each charge being
tempered about four minutes. It is then carried on an endless belt to
the pipe press. In their old building the company has Barber sewer-
pipe presses, and Penfield presses in the new works. There are several
FIRE-CLAYS AND PIPE-CLAYS IN NORTH CAROLINA. 91
stories of slatted drying floors in each of the two factories, and the heat
is supplied by coils of pipe on the lower floor. The diameters of sewer-
pipe made are the usual ones up to 24 inches in diameter, inside measure.
A second grade of sewer-pipe of the same sizes, manufactured here, is
now used largely as a substitute for stone culverts at public road cross-
ings. And in addition to these the company manufactures the follow-
ing: Terracotta well tubing, 10 to 24 inches inside diameter, and 2 feet
long; terracotta chimney flues; and farm drain tile 2^ to 12 inches in
diameter.
The burning is done in circular down-draft kilns, 26 ft. in diameter
and 8i ft. high, with inclined grate bars in the fire-places. Soft clinker
coal is used for fuel. There are 12 kilns altogether, with one stack
for two kilns. (See Plate I, frontispiece, for a general view of the
works.)
Flue linings and semi-fire-brick are also made and burned in the same
kilns.
The company has an abundance of available clay, as it controls much
land bordering the North Buffalo creek and has exploited the clay
b^ds to a considerable extent. It has a complete modern plant, having
recently more than doubled its capacity, and is turning out some excel-
lent material.
CHAPTER VIII.
, BRICK-CLAYS AND BRICK MANUFACTURE.
GENERAL CHARACTER OF BRICK-CLAYS.
Clays suitable for the manufacture of common brick are so widely
distributed in North Carolina that it is hardly necessary to say more
here than to refer to the detailed descriptions of the more important
occurrences.
In North Carolina two kinds of clay are used:
1. Residual clays.
2. Sedimentary clays.
The residual clays are to be found all over the Piedmont plateau and
mountain regions of the state, and their thickness depends on the depth
to which the rocks have disintegrated, and also on the slope of the land,
for on steep slopes the material is rapidly washed away. Residual clays
are usually impure. Those around Greensboro, which are the most
worked, showed from 8-12$ total fluxes. Owing to the high percentage
of undecomposed mineral matter in some of them, they are generally
gritty, sandy, and possess little plasticity. They frequently absorb a
large amount of water in molding, which they have to give off again in
drying, with the consequent danger of checking; this is especially apt to
happen when the soft-mud process of hand-molding is used. Owing to
their coarseness of grain the residuals do not fuse incipiently under
2000°-2100° F., while the sedimentary clays generally reach the same
condition at 1900° F. As very few of the smaller brickmakers reach
a temperature of over 1950° F. in burning, the brick are generally
underburned, porous and weak.
It has been noticed that when these clays are molded in a steam-
power machine, especially a stiff-mud machine, which requires less water
to be added to the paste, the resulting brick is smoother and denser.
Having less water, it shrinks less in drying, and consequently there is
less danger of cracking. The use of some permanent form of kiln also
gives better results, as the heat can be better regulated.
The sedimentary clays are found unde^Jying terraces along the rivers
or else in the valley bottoms, where the} represent the accumulation
of clay sediments in lakes or ponds. These clays are far preferable
to the residual ones, for they burn dense at a lower temperature; they
are more plastic, smoother, have greater tensile strength, and generally
burn to a better color than the residual clays.
J
BRICK-CLAYS AND BRICK MANUFACTURE. 93
REQUISITES OF BRICK-CLAYS.
The more impure clays are generally used for the manufacture of
building brick. They should burn to a good red color, preferably at a
temperature not greater than 2000° F. or 2100° F. They should have
enough fluxes to cement the particles to a hard and dense body at the
above temperature. From 5-7$ of iron is desirable, as this amount has
generally been found to exert the best coloring action. A large amount
of lime is undesirable, for it brings the temperatures of fusion and
incipient vitrification too close together, although Seger has shown that
with care a good brick may be made from a clay containing 20-25$ of
calcium carbonate. Its tendency, as previously stated (chemical prop-
erties of clays), is to lessen the shrinkage. If brick-clays contain lime,
it should be finely and evenly disseminated, for if in lumps, these are
apt to split the burned brick (see p. 21).
Sand seems generally to decrease the plasticity and tensile strength,
whether present in coarse grains as in the laminated black clay on the
Cape Fear river at Prospect Hall, or in a finely divided condition as in
the kaolin four miles west of Troy. It also diminishes the shrinkage to
a A^ariable extent. Indeed, sand is sometimes added to very plastic
clays to facilitate molding and decrease the shrinkage in drying and
burning. It should be borne in mind, however, that it is harmful to
go to the other extreme and add too much sand, for the tendency is to
produce a weak, porous brick, especially if hand-molded.
Fine-grained clays and very plastic ones generally require slow dry-
ing. The reason for this is that on account of the smallness of the pores
the moisture cannot escape so readily, and the outer portion of the
brick dries and shrinks quicker than the interior. The result is crack-
ing. Kapid drying may be prevented somewhat by adding salt water
to the clay; this is a common practice in portions of Missouri.1
Fine-grained clays very often have to be heated slowly in the early
stages of burning, although in the case of fine-grained clays with an
abundance of fine sand they can generally be heated rapidly, so far as
the North Carolina clays are concerned.
The range of the various constituents in the North Carolina brick-
clays is as follows :
Range of Constituents in North Carolina Brick-Clays.
Range. Average.
Silica * 52-70 G0.00
Alumina 13-2S 18.00
Ferric oxide | 1.5-11.5 6.00
Lime ?* 0.10-2.5 O.fiO
Magnesia 0.10-1.5 0.40
Alkalies
0.20-4.5
2.00
Water
4-12
7.00
Total fluxes
3.5-17.5
1 Mo. Geol. Survey, XI, p. 481.
9.00
'94 CLAY DEPOSITS IN NORTH CAROLINA.
This is about the usual composition of brick clays, with the exception
of lime and magnesia, which are somewhat low.
METHODS OF BRICK MANUFACTURE.
All clay when made into building brick has to go through the fol-
lowing stages :
1. Preparation (crushing or tempering, or both).
2. Molding.
3. Drying.
4. Burning.
Various methods may be used in each stage of the manufacture, and
this is especially the case in molding, and, therefore, four methods of
manufacture are generally recognized, according to the type of machine
used to shape the clay. These four processes are:
1. Soft-mud.
2. Stiff-mud.
3. Semi-dry press.
4. Dry press.
Each of these processes has certain advantages, and its applicability
depends on the character of the clay, capacity desired, and capital avail-
able.
SOFT-MUD PROCESS.
In North Carolina this is the one most generally used. It is adapt-
able to almost any clay, and requires the least amount of capital.
Tempering- the Clay. — The clays used are generally soft ones, such
as require no grinding. They are first tempered with water. This is
done either by throwing the clay into a large rectangular pit behind
the molding machine, pouring water over it and allowing it to soak, or
else tempering it in ring-pits. These consist of circular pits 15-20 feet
in diameter and 2-3 feet deep. In each pit there revolves a large iron
wheel attached to a post in the centre, and so geared that it travels
back and forth from the centre to the circumference of the pit as it
travels around. The clay is shoveled into the pit, water poured over it
and the mass allowed to soak for 12 hours, and it is then mixed by the
wheel for about six hours more. This is by far the best method of
tempering clay for the soft-mud process, for it mixes the clay into a
homogeneous mass, which is something a soak pit does not do.
Many small manufacturers in the South have a rather crude arrange-
ment for tempering their clay. It consists of a vertical rectangular
box, in which there is set an upright shaft with cross-arms. The clay
is thrown in at the top, and by the revolution of the shaft, operated by
horse-power, it is forced slowly downward and out at the bottom.
BRICK-CLAYS AND BRICK MANUFACTURE. 95
Pugmills are sometimes used in connection with soft-mud machines,
but are more frequently used in connection with the stiff-mud process,
and will be described under that head.
Molding the Brick. — The clay is molded by hand or in machines
operated either by steam or horse-power. When the clay is molded by
hand it is generally tempered somewhat softer, often too much so. A
wooden mold is used. The molder takes a chunk of clay from his
supply on a table near him, and forming it roughly he lifts it up and
then throws it downward into the mold, which has been previously
sanded on the inside to prevent the clay adhering. The mold is then
reversed onto a pallet, the brick drops out and is carried off by a boy,
the " off-bearer," and placed on the yard to dry.
A man can mold about 2500-3000 bricks per day by this method.
The day's work of molded brick, which have been spread out on the
yard to dry, are turned on edge at the end of the day to permit equal
drying. Sometimes a boy goes along the rows of brick and, with a flat
board fastened to the end of a stick, stamps the brick in order to square
them up in case the clay was too wet to hold its shape.
Hand-molding is a cheap method as far as cost of plant is concerned,
but the capacity is small. Hand-made bricks are generally porous and
light, as the clay receives little pressure in molding, but they are homo-
geneous in structure, and when hard-burnt are usually strong.
The celebrated Philadelphia red front brick were for a long time
molded by hand and then re-pressed.
When soft-mud brick are molded by machine the clay is fed into the
upper end of a rectangular box, which is really a vertical pugmill. The
clay passes downward and is forced into a six-brick mold at the bottom;
the latter, as soon as filled, being thrust out. Such machines have a
capacity of about 20,000 brick per day. It requires from 5 to 7 men to
operate one of these machines, that is, a shoveler, mold-sander, mold-
lander, who receives the mold and trims off the superfluous clay, and
two or three off-bearers to spread the brick on the yard.
Drying. — Soft-mud bricks are generally dried in the sun. As this
method requires considerable space, especially when large capacity is
required, it is sometimes found desirable to dry the brick on pallets
set one above the other on racks. This increases the drying capacity,
avoids handling until the brick are set in the kiln, and there is no loss
from washed brick. The drying takes a little longer.
Burning. — Soft-mud bricks are usually burned in scove-kilns; that
is, they are piled up in rectangular masses 35-iO courses high, and open
spaces or arches are left at intervals in the bottom of the pile these
arches running through the mass.
The exterior of the " kiln " is daubed over with mud. and one or two
96 CLAY DEPOSITS IN NORTH CAROLINA.
courses of brick, called the " platting," are laid natside down on the
top of the kiln to keep the heat in. Fires are then built in both ends
of the arches, and the interior of the kiln is gradually heated to the
desired temperature.
Burning is the most important step in the manufacture of brick. It
is important that the heat should be raised slowly during water-smoking
and also while the combined water is being driven off, and, furthermore,
that the temperature should be distributed as evenly as possible through-
out the kiln, for it is a common fault at many of the smaller yards that
the arches are almost melted while the upper courses can sometimes
barely be called salmon brick. In this connection there may be men-
tioned the practice followed by some manufacturers of adding coal-dust
to the brick to be placed in those parts of the kiln which do not receive
sufficient heat. In burning, the coal-dust in the brick ignites and sup-
plies additional heat where it is needed. The coal dust is added in the
proportions of one bushel to clay for 1000 brick, and is added to the
clay before it is tempered. Wood is the fuel commonly used in burning
soft-mud brick. The arches are often closed by iron doors, and these
should never be omitted, for a flood of cold air rushing into a mass of
red-hot brick is sure to do damage.
If the heat is raised too rapidly, the outer part of the brick shrinks
and becomes dense before the ferrous oxide of the interior has been
converted to the ferric oxide, and a black core is generally to be seen
in such cases; unequal shrinkage and consequent cracking also results
from the same cause.
STIFF-MUD PROCESS.
Preparation of the Clay. — This method of making brick is appli-
cable to either shales or clays. In the case of the former they generally
have to be prepared by grinding them in a dry pan. This consists of a
large circular revolving iron pan about 9 feet in diameter (fig. 4=,
p. 97). In this there are two iron rolls weighing 3000-1000 pounds
each, and which revolve by friction against the bottom of the pan. The
outer part of the bottom is perforated by slits one-fourteenth to one-
sixteenth inch diameter, according to the fineness to which the material
is to be ground.
For softer shales and tough clays a disintegrator is used.
Many of the North Carolina manufacturers pass their clay first
through a pair of rolls, but as in most instances where these are used
the clay contains no stones and needs only tempering, the advantage
of using the rolls is not apparent.
Tempering the Clay. — For a stiff-mud machine the tempering is
generally done in a pugmill. This consists of a horizontal trough ir»
BRICK-CLAYS AND BRICK MANUFACTURE.
97
which there revolves a shaft bearing knife blades set at a small angle.
The clay and water are fed in at one end and as they are pushed for-
ward towards the other end, where they are discharged into the machine,
they become thoroughly mixed. This is of considerable importance, for
in the case of laminated clays their structure should be destroyed by
thorough mixing. Pugmills are generally six or eight feet long, and
the longer the better. A wet pan gives better results than a piigmill,
for it not only crushes a soft clay but tempers it thoroughly.
Fig. 4. — Dry-Pan Ckusher.
There are many stiff-mud auger machines put on the market which
have a pugmill about three feet long, and many manufacturers have
bought them, probably for cheapness. In almost every case they give
dissatisfaction unless the clay is thoroughly tempered before being
molded in them, for the pugmill is entirely too short to be effective.
Molding. — Two types of stiff-mud machines are used, the plunger
.and the auger. In both the clay is discharged in the form of a rect-
angular bar. The plunger machine is intermittent in it- action; the
auger is continuous, sometimes intermittent, and perhaps tic favorite
method. The bar of clay may be 2^x4- inches or 9x4, according as the
brick is to be an end-cut or side-cut one.
The capacity of an auger machine is usually Prom 50,000 to 70,000
per day, but it may be less or more. Anger machine brick- arc apl to
he laminated, which aives a shelly structure to the brick. Some clavs
98 CLAY DEPOSITS IN NORTH CAROLINA.
show this more than others, and the same clay may show more lamina-
tions when side-cut than end-cut. Very plastic clays usually laminate
the most.
Auger machine brick are often repressed, especially if to be used for
paving or fronts. If pressed brick are to be made it is important to
test the clay on different stiff-mud machines first to determine which
works the best. Plate VIII shows an auger end-cut brick machine
(fig. 1), and a re-pressing machine (fig. 2).
The bar of clay as it is cut up into bricks is received on a belt which
carries the brick to the repressing machines or else to the " off-bearers."
who place them on cars which are run into a drying tunnel. Stiff-mud
brick are stiff enough when molded to permit of their being piled 6 or
8 courses high on the drying cars without crushing out of shape.
Re-pressing sharpens the form of the brick, but adds considerably to
the cost of manufacture.
The brick, when piled on the cars, are run into long tunnels, which
are heated by steam, coal or oil (see Plate VII, Hg. 2, p. 88). Recently
successful experiments have been made towards utilizing the waste
heat from the cooling kilns for drying the brick. The rapidity of the
drying varies from 20 to 50 or 60 or more hours according to the clay.
Rapid drying cracks many clays.
Few stiff-mud brick are dried in the sun.
Burning. — This is done either in up-draft or down-draft kilns. The
wp-draft kilns generally have permanent side walls, the ends and top
being closed up with brick and those at the ends daubed with mud.
Such kilns usually have a capacity of 150,000 to 200,000. The up-
draft kilns are cheaper to construct than down-draft ones, but there is-
a greater percentage of salmon brick obtained. Figure 1 of Plate X
(p. 101) shows an up-draft kiln used at the state penitentiary at Raleigh.
This has permanent side walls, which are braced by brick offsets.
Continuous kilns are sometimes used. This is the ideal method of
burning brick and the cheapest. They have been used most successfully
abroad and are gradually coming into extended use in this country..
The continuous kiln consists essentially of a long chamber of oval form,,
which is divisible into compartments by means of temporary partitions.
Each compartment has one or two entrances for wheeling the green
brick in and the burned brick out. There are four or more openings,,
covered by caps in the top of each chamber for feeding the fuel, as
will be mentioned later.
In the walls of the kiln are a series of flues connecting the chambers
with the chimney, and also by means of dampers, making connection
possible between any two chambers. Each chamber has a capacity of
20,000 to 22,000 brick, and in setting them vertical spaces are left under
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE VIII.
FIG. 1.— 3TIFF-MUD AUGER END-CUT BRICK MACHINE.
Shows a bar of clay issuing from the die of the machine. This is cut across by a wire at proper
intervals, thus dividing it into brick.
FIG. 2. — RE-PRESSING BRICK MACHINE.
The brick to be re-pressed are brought from the moulding machine on a belt Us shown in the
foreground), from which they are taken by a workman who places them,
two at a time, into the machine.
N. C. GEOLOGICAL SURVEY.
BULLETIN 13. PLATE IX.
FIG. 1.— INTERIOR VIEW OF A CONTINUOUS BRICK-KILN.
FIG. 2.— EXTERIOR VIEW, CONTINUOUS BRICK-KILN.
BRICK-CLAYS AND BRICK MANUFACTURE. 99
the charging holes in the roof. As each chamber is filled the temporary
(often paper) partition between it and the next one is put up, the object
of this being simply to prevent the draft from passing straight through
the whole kiln.
After each chamber is filled the two entrances are bricked up, leaving
a charging space, which is covered by an iron door. The kiln is started
by building a fire in the doorway of the first chamber and gradually
heating it up to the desired temperature. Coal slack is also charged
through the openings in the top. Many manufacturers no longer use
the top openings, but feed all the fuel through the doorways.
The important principle of the continuous kiln is that the heat from
this burned chamber is conducted into the next one either through the
flues in the wall or else through sheet-iron pipes placed to connect the
roof openings. In this way the heat raises the temperature of the next
chamber, so that less fuel need be used. When the kiln is once started
it takes from 200-300 pounds of fuel per 1000 brick.
The heat from a burning chamber cannot as a rule be carried safely
through more than three or four chambers before taking it off to the
chimney. The reason for this is that the hot-air collects moisture from
the brick in these chambers which are being heated up; it will easily
be seen that if carried through too many chambers the air will lose so
much heat that instead of gathering moisture it will begin to deposit it
on the brick.
It is sometimes necessary to aid the draft of a continuous kiln by
means of a small fan. The number of chambers in the kiln depends
on the size of the yard and available capital.
Continuous kilns are used in this country for burning common and
front brick, paving brick and fire-brick.
~No continuous kilns are in use in North Carolina, so that the illus-
trations shown are from one at the Catskill (N. Y.) Paving-Brick Works.
Fig. 1 of Plate IX shows the interior view of the kiln, which is empty,
while fig. 2 of the same plate shows the exterior view.
DRY-PRESS PROCESS.
This method is applicable to a variety of clays, but not to very sandy
ones, which have little cohesive nature. The advantages of it are wide
to'
range of character permissible in clays used, the brick made are sharp-
edged and smooth, and the green brick can generally be set directly in
the kiln.
The disadvantages of this method are, the necessity of weathering
the clay, increased cost of plant, and limited capacity.
Dry-press brick when properly burned arc a- strong aa other brick,
but if underburned they are easily affected by the weather.
100
CLAY DEPOSITS IX XORTH CAROLINA.
Preparation of the Clay. — The clay for making dry-press brick is
generally weathered first. This is accomplished by piling the clay up
under large sheds or spreading it out over the ground in a layer one to
two feet thick. If possible, it is frequently best to allow the clay to
weather for several months or even longer, depending on the nature of
the material. By this weathering the moisture becomes evenly dis-
tributed through the clay, the frost breaks it up and the decay of
organic material by the disengagement of carbonic acid produces the
same effect. The iron compounds may also become further oxidized.
Clays weather more actively in winter than in summer.
Fig. 5. — Drt-Pkess Bkick Machine.
When ready for use the clay is first pulverized, usually in a cen-
trifugal disintegrator of the Steadman type, and then passed through
a screen with meshes varying from one-eighth to one-sixteenth inch,
N. C. GEOLOGICAL SURVEY.
BULLETIN* 13. PLATE X.
iWUHlfr BR
FIG. 1 .— UP-DRAFT BRICK-KILNS, FOR BURNING COMMON BRICK, AT THE STATE PENITENTIARY,
RALEIGH, N C. 'See page 98.)
FIG. 2— DOWN-DRAFT BRICK-KILN, EUDLAY TYPE. (See also page 141.)
BRICK-CLAYS AND BRICK MANUFACTURE. 101
the finer mesh being used for front brick. The clay should not con-
tain too much moisture, as otherwise it clogs the screen.-
Molding the Brick, — The dry -press consists essentially of a steel
mold box with movable top and bottom. The clay is fed into the
mold automatically, and the plunger descends into the mold from above,
the pressure being applied by means of a toggle-joint or cam. After
the clay is pressed the plunger rises, as does also the bottom of the mold,
until the brick is level with the table, on which it is pushed forward
by the charger as it advances to refill the mold. The brick are set on
hand-cars and carried off to the kilns.
If the clay is very dry the edges are apt to crumble, and the brick
will not bear much handling. To avoid this the clay is sometimes dis-
charged from the screen into a pugmill, where it is moistened with
steam. This gives a brick with sharper edges and one which bears
handling better. The term semi-dry press is used when the clay is
moistened somewhat.
There are numerous types of dry-press machines, among which may
be mentioned those of the Boyd (fig. 5, p. 100), Simpson, Whittaker,
and Chambers patterns. The slower the pressure is applied in molding
the brick the less air will there be enclosed in it, and the less will be
the danger of its bursting by the expansion of the air.
Burning. — Dry-press brick are burned in either up-draft or down-
draft kilns. This process has to be conducted very slowly, for both the
drying and water-smoking have to be done in the kiln, and, on account
of the dense nature of the brick, the water can only escape slowly.
Drying and water-smoking may therefore take from six to eight days.
In burning front brick it is important that as few as possible should lie
exposed to the direct action of the flames. In up-draft kiln- the
arch brick are generally warped and discolored, while in down-draft
kilns the top courses are generally fire-flashed and also discolored from
the ashes of the fuel. These top brick are harder burned than the
bottom ones, and while useless for front brick, if not cracked they are
often desirable for walks or sewers.
The down-draft kiln is preferable for burning front brick, a- there
is less loss in the form of overburned or underburned brick. Plal X.
fig. 2, shows the Eudaly type of down-draft kiln, which is in common use.
CHAPTER IX.
BEICK-CLAY DEPOSITS IN NOKTH CAEOLIXA.
CLAYS IN BLADEN COUNTY.
Near Prospect Hall. — Following down the Cape Pear river from
Fayetteville, after passing Willis creek, there begin to appear large
quantities of black clay in the bluffs along the river. One of the best
sections is to be seen in a bluff 60 feet high on the property of Wil-
liam Whitted at Prospect Hall (see Plate XI, fig. 1, p. 110).
The upper 20 feet of the bluff are sand and gravel often heavily
stained with iron, but the lower forty feet are mostly black clay, roughly
separated into three somewhat lens-shaped beds, as follows:
Black, sandy clay, 8-10 feet (field sample No. 11).
Sand and sandstone, 10 feet.
Black, sandy clay, 8 feet (field sample No. 10).
Black clay, 4 feet, exposed at base of bluff (field sample No. 12).
The upper black sandy clay of the section (Xo. 11) has in places
abundant mica scales, and sometimes coarse sand grains. It slakes
slowly to large scaly fragments. Pyrite and lignite are both scattered
sparingly through the clay, but the pyrite is mostly in small grains.
The addition of 38/c of water gave a mass that was lean and gritty.
This paste shrunk 6$ in drying and 8^ in burning, giving a total shrink-
age of 14:fo. Air-dried briquettes of this paste had an average tensile
strength of 64 lbs. per square inch and a maximum of 77 lbs. per
square inch. Incipient fusion occurs at 1900° F., vitrification at 2100°,
viscosity at 2300°. It burns to a deep red, dense body.
The composition of this clay is:
Analysis of Brick-clay {No. 11), Prospect Ball.
Moisture 4.50
Silica (total) 56.13
Alumina j 17.80
Ferric oxide 5.85
Lime 10
Magnesia 79
Alkalies 2.45
Water (loss on ignition) 11.60
Total 99.22
Free sand 27.18
Total fluxes 7.29
Specific gravity 2.34
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 103
No. 11 is similar to E"o. 10, but contains more coars.e grit, and the mica
scales are abundant. It slakes slowly to large fragments, and required
the addition of 22^ of water to make a workable paste, which is very
lean. This paste shrunk 5$ in drying and 8^ in burning, giving a total
shrinkage of 13$. The tensile strength is very low as indicated by the
plasticity, being on the average only 46 lbs. per square inch, with a
maximum of 58 lbs. per square inch. Incipient fusion occurs at 2000°
F., vitrification at 2150° F., and viscosity at 2300° F. The clay burns
to a deep red body.
Its composition is as follows:
Analysis of Brick-clay {No. 10), Prospect Hall.
Moisture 2.80
Silica (total) ' 63.30
Alumina 15.87
Ferric oxide 5.48
Lime 27
Magnesia 21
Alkalies 2.10
Sulphur 1.78
Water (loss on ignition) 8.25
Total 100.36
Free sand 57.30
Total fluxes 10.11
Specific gravity 2.13
The organic matter is noticeable from the loss on ignition which the
clay undergoes. The total percentage of fluxes is greater than in Xo.
11, but their fluxing tendency is more than offset by the sand present.
No. 12 is the best clay of the three, as it contains less sand, mica scales
and pyrite. It is also more homogeneous, harder and denser. The sand
and mica grains are mostly between the layers of the clay. The clay
slakes slowly to large scaly fragments. It soaks up a large quantity of
water, and required 40$ to make a workable mud that had little plas-
ticity. This mud shrunk 12$ in drying and 5$ in burning, giving a
total shrinkage of 17$. The air-dried briquettes made from this paste
had an average tensile strength of 59 lbs. per square inch and a max-
imum tensile strength of 90 lbs. per square inch, [ncipiejil fusion
occurred at 1900° F., vitrification at 2100° F., viscosity at 2300° F.
The composition of the clay is as follow-:
Analysis of Brick-clay [No 12), Prospect Ball.
Moisture 4.26
Silica (total) •"'"'■, >•">
Alumina 20.8(3
10-J: CLAY DEPOSITS IN NORTH CAROLINA.
Ferric oxide 5.11
Lime 30
Magnesia 04
Alkalies 2.13
Sulphur 1.18
Water (loss on ignition) 9.94
Total 100.07
Free sand 15.05
Total fluxes 9.36
Specific gravity 2.30
The chief objection to these clays is their lean character. They stand
rapid heating and burn easily to a dense red body.
If molded into brick, it shonld be done by machinery that would give
them good pressure, and not by hand. The admixture of a more plastic
clay would be a still better method to follow.
They might possibly be worked for paving brick.
CLAYS IN BUNCOMBE COUNTY.
Penniman Clxvy Bank near Emma. — Along the line of the Southern
R. R., southwest of Asheville, on the road to Murphy, deposits of sedi-
mentary clays are to be found at a number of localities. Their largest
development is at Emma, two miles west of Asheville, where consider-
able quantities of brick are made by W. R. Penniman.
The section exposed in Penniman's bank is as follows:
Upper red clay 4 feet.
Lower gray clay (" fire-clay ") 3-10 feet.
Sand
The upper clay is tough, gritty, highly colored, and in places seems
to grade downward into the under gray clay.
The upper or brick clay slakes quickly to grains of sand and mica and
fine aluminous mud.
The addition of 20^ of water gave a workable paste of somewhat
plastic feel. This paste shrunk 9$ in drying and 4$ in burning, giving
a total shrinkage of 13^. The air-dried briquettes made from this mud
had an average tensile strength of 63 lbs. per square inch, with a max-
imum of 80 lbs. per square inch. Incipient fusion occurred at 2000°
E., vitrification at 2200° E., and viscosity at 2400° E.
The clay burns to a good red body. The following is the analysis:
Analysis of upper Brick-clay (iVT'>. 59). Penniman's.
Moisture 1.15
Silica (total) 66.27
Alumina 19.95
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 105
i Ferric oxide 3.16
Ferrous oxide 07
Lime 20
Magnesia 32
Alkalies 1.85
Water (loss on ignition) <;.17
Total 99.74
Clay substance 49.34
Free sand 50.40
Total fluxes 0.20
Specific gravity 2.50
The iron is mostly oxidized, as will be seen from the analysis and
also indicated by the color of the clay.
The under clay at this yard goes by the name of fire-clay. It is a
coarse-grained clay, full of mica scales and small angular quartz grain-.
In water it slakes quickly and completely, and on the addition of 28$
of water gave a workable and moderately plastic paste which shrunk
7$ in drying and 4$ in burning, giving a total shrinkage of 11$. The
average tensile strength of the air-dried briquettes made from this clay
was 58 lbs. per square inch, with a maximum of 60 11>-.
Incipient fusion occurs at 2050° F., vitrification at 2250° F., ami
viscosity at 2450° F. The clay burns gray buff. ■ The composition of
the clay is as follows :
Analysis of lower Brick-clay {"fire-clay") [No. 58), Peniriman's.
Total portion. Insoluble portion.
Moisture 80
Silica (total) 70.60 55.70
Alumina 17.21 .40
Ferric oxide 3.44 .5G
Lime 10
Magnesia 07
Alkalies 2.45 1.32
Water (loss on ignition) 5.00
Total . 99.73 57.98
Total fluxes 7. m
Specific gravity 2.48
From the above analysis we obtain:
Clay substance U.75
Quartz 54.30
Feldspar 3.68
106 CLAY DEPOSITS IN NORTH CAROLINA.
This clay is not unlike the bottom clay at Bethania, but contains
more free sand. The grains of the latter are mostly quartz, as seen
from the rational analysis.
This type of clay is not uncommon in ]N"orth Carolina, the clays at
Grover being of this kind, but they contain less iron. The predom-
inant character, however, is the fine-grained clay substance with the
coarse quartz grains scattered through it,
Mr. Penniman uses the upper clay for making common brick and
also for re-pressed brick, for it burns to a good red color. The brick are
molded in a Sword's machine, dried in the sun and burned in up-draft
open kilns with permanent side walls, of 185,000 capacity. The fuel
is coal. ■
The brick made from the lower clay are burned in the same kiln and
at the same time as the red clay. They are re-pressed. The chief use
of the lower clay brick is for boiler and furnace foundations and for
furnaces requiring only a low degree of heat. The bricks are white
or yellowish-white, and not burned very hard.
It is probable that a mixture of the upper and lower clay would make
a paving brick, although if a more plastic and slightly more fusible clay
than the upper one could be mixed with the lower clay, still better
results would be obtained. Such clays are to be found in many of the
lowlands along the valleys near Asheville.
Clays near Asheville and Biltmore. — The French Broad river
near Asheville is bordered at several points by broad stretches underlain
by clays of good quality for various purposes. Such a deposit has been
worked at Biltmore with eminent success, the products being common
and pressed brick, drain tile, and paving brick. The deposit has been
covered up now to permit land improvements, but the same belt of clay
land borders the river at other points.
It should be noted that the methods and machinery used at Biltmore
were of the most approved type.
Poor products may result very often as much from carelessness in
manipulation and the use of the wrong appliances and methods as in
the use of improper clay.
The other brickyards around Asheville are working residual clays for
making common brick to supply a local demand.
Clays near Fletcher. — The Buncombe Brick Co. at this locality
is engaged in the manufacture of both common, pressed and paving
brick. Their main bank is a light gray clay of slightly plastic and
somewhat gritty feel. It is fine-grained and slakes slowly. The addi-
tion of 25.5$ of water was required to give a workable mass, which
shrunk 4$ in drying and 7$ in burning, making a total shrinkage of 11$.
The air-dried briquettes had an average tensile strength of 37 lbs. per
square inch and a maximum of 40 lbs. per square inch.
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 107
Incipient fusion occurs at 2000° F., vitrification at 2200° F., and
viscosity at 2400° F.
The chemical composition of the clay is :
Analysis of Brick-clay {No. 65), near Fletcher.
Moisture 1.10
Silica (total) 75.08
Alumina 13.73
Ferric oxide 3.47
Lime 30
Magnesia 17
Alkalies 1.48
Water (loss on ignition) 4.65
Total 99.98
Clay substances 45.18
Free sand 55. SO
Total fluxes 5.42
Specific gravity 2.41
CLAYS IN BURKE COUNTY.
Near Morganton. — The clay underlying the terrace along the river
two miles west of the town becomes more sandy in character towards
the river. A sample from the brickyard of Mr. McDowell along the
river had 60^ of sand, while along the road, back from the river, there
was only 54^.
The clay as exposed in McDowell's brick-clay bank (Xo. 52) is a
loose, sandy, coarse clay, with abundant mica scales and quartz grains.
It slakes very quickly and completely to its component grains. The
addition of 22$ of water gave a lean but workable mud which shrunk
6$ in drying and 5^ in burning, giving a total shrinkage of IK.
The average tensile strength of the air-dried briquettes was 50 lbs.
per square inch, with a maximum of 83 lbs.
Incipient fusion occurs at 1950° F., vitrification at 2100° F., and
viscosity at 2250° F. The clay burns dark red at 2100° F.
The analysis of it gave:
Analysis of Brick-clay {No. 52), McDuicelVs day bank.
Moisture 1.80
Silica (total) 67.03
Alumina L6.88
Ferric oxide ,; 50
Lime 1-00
Magnesia 1.16
Alkalies 90
Water (loss on ignition) 4.78
Total 100.05
10S CLAY DEPOSITS IN NORTH CAROLINA.
Clay substance 39.90
Free sand , 60.05
Total fluxes 9.56
Specific gravity 2.61
The clay is used for making common brick, but they are molded in
ordinary hand-molds and burned barely to incipient fusion; with more
care and better machinery a very good brick could be made from it.
Probably there could be found a more plastic clay in the lowlands
between the railroad and the Xorth Carolina Insane Asylum.
CLAY IN CLEVELAND COUNTY.
Xear Grover. — Occurring in the region around Grover are beds
of surface clays which have no connection with the so-called fire-clays
previously mentioned (p. 81). At the works of the Cleveland Brick
Company just south of Grover, one of these beds has been opened up
and consists of an upper bed of tough, red, mottled clay, 6 feet thick,
and an under bed of very plastic clay not less than 3 feet thick.
The under clay (No. 46) is a gritty clay with small mica flakes and
coarse sand grains. It is slow in slaking. 35$ of water was required to
give a workable mass that shrunk 9$ in drying and 6.5$ in burning,
giving a total shrinkage of 15.5$. Air-dried briquettes of the clay
had an average tensile strength of 98 lbs. per square inch and a max-
imum of 115 lbs. per square inch. Incipient fusion occurs at 1900" F.,
vitrification at 2100° F., and viscosity at 2300° F. The clay burns
a rather light red. •
The analysis of the clay gives:
Analysis of Cleveland Brick Co's. under Clay [Wo. 46), just S. of Grocer.
Moisture 1.18
Silica (total) 61.75
Alumina 23 30
Ferric oxide 3.34
Ferrous oxide 50
Lime 27
Magnesia 25
Alkalies 1.31
Water (loss on ignition) 7.75
Total 99.65
Clay substance 60.62
Free sand 39.05
Total fluxes 5.67
Specific gravity 2.36
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 109
The upper clay is far less plastic, but very tough. It also required
26fo of water to make a workable paste, which was gritty to the feel
and somewhat plastic. This clay shrunk 7.5$ in drying and 5# in
burning, giving a total shrinkage of 12.5^. The average tensile
strength of the air-dried briquettes was 42 lbs. per square inch with a
maximum of 51 lbs. Incipient fusion occurred at 1950° F., vitrifica-
tion at 2150° F., and viscosity at 2350° F. The clay burns red.
The composition of this clay is as follows:
Analysis of Cleveland Brick Co.'s upper Clay (No. 47), just S. of Grover.
Moisture G.°>
Silica (total) 65.45
Alumina 20.02
Ferric oxide 4.18
Lime 25
Magnesia 2!>
Alkalies 1.51
Water (loss of ignition) 6.5S
Total 98.91
Clay substance 47.06
Free sand 51.45
Total fluxes 0.23
Specific gravity 2.61
While the upper clay is not as strong as the lower, still it burn- easier
to a red brick and shrinks less in burning.
The pit is about 300 feet from the yard, and the clay i- hauled in
carts. The tempering is done in a long open pugmill of Chambers's
manufacture. Molding is done in a Chambers's auger automatic end-
cut machine. A pair of rolls were formerly used for breaking the claw
but were found very unsatisfactory. A standard dryer heated by
steam-pipes is used. Exhaust steam is used in the daytime and live
steam at night.
The brick are burned either in scove kiln- or circular down-draft
ones. They are 16 feet in diameter, and there is one stack for every
two kilns, but Mr. Eskridge is about to put a aumber of small chim-
neys on each kiln.
The fire-brick are burned in the circular kiln. They are used for
the roof of the roasting furnaces at the Blacksburg (South Carolina)
acid works, and wear well. The furnace has a diameter of 2<> feet,
and the rise from circumference to centre is s inches.
The hard red brick are used around the acid works and resist the
action of the acid very well.
This clav is not unlike many of the alluvial clays in other parts of
110 CLAY DEPOSITS IN NORTH CAROLINA.
North. Carolina, and they show very well the influence of proper work-
ing and machinery in producing good results.
CLAY IN CUMBERLAND COUNTY.
Near Fayetteville. — South of the town are extensive beds of sedi-
mentary clays, whose general section involves 2-3 feet of coarse sand
underlain by at least eight feet of clay, and sometimes probably more.
The clays are best exposed at Poe & Bros.' yard, a half mile south of
Fayetteville. The clay as exposed here is a fine-grained, tough, bluish-
white clay with frequent thin iron stains, which give it a mottled
appearance. In some portions of the bank the clay is very smooth
and free from iron stains, and has been used for stoneware. ('Plate XI,
fig. 2.)
At the south of the pit is a bed of very tough clay, fine-grained and
broken by numerous small joints running in every direction. This por-
tion is not used, as it is claimed to be too tough to work.
A sample of the average run of the bank, excluding the top sand and
tough clay, which is not used, showed the clay to be a somewhat gritty,
medium-grained, tough clay which slakes quickly to grains ^-tOw*11 .
in diameter. It required the addition of 28 fo of water to make a work-
able mud, which felt quite plastic. This mass shrunk 8.5$ in drying
and 5fo in burning, giving a total shrinkage of 13. 5£. The air-dried
briquettes of this paste had an average tensile strength of 14-1 lbs. per
square inch and a maximum of 175 lbs. per square inch.
Incipient fusion occurs at 1900° F., vitrification at 2050" F., and
viscosity at 2200° F. The clay burns deep red.
The chemical composition of the clay is as follows :
Analysis of Pot's Brick-clay {No. 14), y2 mile S. of Fayettetille.
Moisture 2.48
Silica (total) 64.93
Alumina 17.0S
Ferric oxide 5.57
Lime 43
Magnesia 59
Alkalies 3.85
Water (loss of ignition) 6.58
Total 101.51
Clay substance 53.13
Free sand 45.90
Total fluxes 10.44
Specific gravity 2.55
A sample of the so-called " tough " clay was also tested with the
following results. It is a dense, somewhat gritty clay which slakes
s.1
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE XL
FIG. 1.— BLACK CLAY ALONG CAPE FEAR RIVER, AT PROSPECT HALL.
(See page 102.)
FIG. 2. — POE BROTHERS' CLAY BANK, FAYETTEVILLF., N. C.
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. Ill
slowly to rounded granules of variable size, mostly above o in. Little
mica was noticeable.. It required the addition of 28.5^ of water to
make an easily worked paste, which shrank 9.8$ in drying and 7< in
burning, giving a total shrinkage of 16.8$. Air-dried briquettes of this
clay had an average tensile strength of 84 lbs. per square inch and a
maximum of 120 lbs. per square inch. Incipient fusion occurs at
1850° F., vitrification at 2050° F., and viscosity at 2250° F. The clay
burns deep red, and requires somewhat slow heating to prevent crack-
ing. The composition of the clay as shown by analysis is as follow-:
Analysis of the "tough clay1' [No. 15), Poe's bank, l/2 mile S. of Fayetteville.
Moisture 3.23
Silica (total) 58.17
Alumina 20.10
Ferric oxide 7.43
Lime 00
Magnesia 77
Alkalies 2.60
Water (loss of ignition) 7.34
Total 100.24
Clay substance 48.09
Free sand 52.15
Total fluxes 11.40
Specific gravity 2.45
The greater toughness of this clay is due to its density.
This " tough clay " could probably be mixed advantageously with
the other. As this clay is manufactured into a very good brick, it may
be well to mention the method followed. The clay and sand are first
dumped into soak pits. From these they are shoveled into a Penfield
plunger machine and issue from this onto the cutting table, where they
are cut up into brick, the frame carrying the cutting wires being oper-
ated by hand-power. The drying is usually done on pallets and pro-
ceeds very slowly. The burning is done in permanent side-wall, up-
draft kilns, having a capacity of 170,000. Re-pressing the brick has
been attended with favorable results.
CLAY IN FORSYTH COUNTY.
Near Bethania. — The largest brick-making plain in the State is sit-
uated at this locality. It is owned by Messrs. Carter and Shepard.
(Plate XII, fig. 1, p. 120.)
The clay bank adjoins the yard and consists of a gray clay, the up] er
portions of which are intermixed with the wash of residual clay fr< m
the neighboring slopes. The lower portion, of which there is an
112 CLAY DEPOSITS IN NORTH CAROLINA.
abundance, is much superior to the top mixture, and the two have been
tested separately to determine their relative advantages.
The lower clay (32) is tough, somewhat coarse-grained, with grains
of quartz and small mica scales. It slakes slowly to grains.
The addition of 25^ of water gave a very plastic, workable mass,
which shrunk 10$ in drying and an additional 5$ in burning, giving a
total shrinkage of 15#. The tensile strength of the air-dried briquettes
showed an average of 127 lbs. per square inch and a maximum of 160
lbs. per square inch.
Incipient fusion occurs at 1900° F., vitrification at 2100° F., and
viscosity at 2300° F. The clay burns buff to red, dependent on the
temperature.
The composition of the clay is as follows :
Analysis of lower Brick-clay (No. 32), Bethania.
Moisture 90
Silica (total) 64.39
Alumina 19.11
Ferric oxide 5.39
Lime 80
Magnesia 22
Alkalies 1.72
Water (loss on ignition) 7.75
Total 100.28
Clay substance 53.18
Free sand 46.60
Total fluxes 8.13
Specific gravity 2.50
The upper mixture is a lean, stiff, sandy clay which slakes easily to
irregular grains and scales. It required 27/£ of water to give a work-
able mud, which was lean and gritty to the feel. This paste shrank
8.5$ in drying and 6^ in burning, giving a total shrinkage of 11.5^.
The air-dried briquettes had an average tensile strength of 65 lbs. per
square inch and a maximum of 89 lbs. per square inch. Incipient
fusion occurred at 2000° F., vitrification at 2150° F., and viscosity at
2300° F. The clay burns to a deep red. Its composition is shown by
the following analysis:
Analysis of the upper Brick-clay {No. 33), Bethania.
Moisture 1.85
Silica (total) 55.S1
Alumina 20.06
Ferric oxide 11.79
Lime 33
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 113
Magnesia 1G
Alkalies 1.42
Water (loss on ignition) 8.80
Total 100.22
Clay substance c>7.-14
Free sand 32.78
Total fluxes 13.70
Specific gravity 2.51
The upper clay contains more iron and burns to a deeper red, but
does not possess the tenacity or plasticity that the lower clay does.
Carter and Shepard's Clay Bank. — This clay at Bethania is used
for brick and drain tile. It is first put through rolls and then a pugmill,
after which it is molded in' a Steele auger machine. The drying is done
either on pallet racks or on heated floors. The brick are burned in a
Morrison kiln and are of a deep red color, but full of lamination-.
If the clay were prepared more thoroughly, and more of the under
clay used, it would probably give better results.
CLAY IN GASTON COUNTY.
IsTear Mount Holly. — The terraces along the Catawba river are well
developed around Mount Holly and furnish an abundance of clay.
About one-quarter mile south of town this clay has been opened up for
the manufacture of brick. The deposit lies at the shore line of the
terrace and about 35 feet above the river. It is not less than seven
feet thick and underlain by sand and gravel. Brick were formerly
made from it by Holobaugh, but the yard is no longer running.
The clay is somewhat gritty and slakes slowly but completely. A few
mica scales are scattered through it.
The addition of 29^ of water gave a very plastic paste, which shrunk
8^ in drying and 4.5^ in burning, giving a total shrinkage of 12. ."»'/.
The average tensile strength of the air-dried briquettes was 131 lbs.
per square inch with a maximum tensile strength of L60 lbs. per square
inch. Incipient fusion occurs at 1950° F., vitrification at 2100 I".,
and viscosity at 2250° F. The clay burns to a close red body.
The analysis of this clay yielded as follows:
Analysis of Brick-clay {No. 60), )i mile S. of Mt. Holly.
Moisture 1.43
Silica (total) (51.28
Alumina 20.83
Ferric oxide 5.51
Lime ''•'
Magnesia 14
8
114 CLAY DEPOSITS IX XOKTH CAROLINA.
Alkalies 81
Water (loss on ignition) 8.75
Total 99.27
Clay substance 50.99
Free sand 19.05
Total fluxes 6.98
Specific gravity 2.17
This clay should make a first-class brick that would stand re-pressing.
In composition and physical properties it is closely similar to the
clay for pottery dug northwest of Lincolnton, but is more san^y in its
nature.
CLAY IN GUILFORD COUNTY.
JSTear Greensboro. — Both residual and sedimentary clays occur in
abundance around the town, and both are utilized by the brick manu-
facturers. The Greensboro Brick and Tile Company's yard is located
on the northern edge of the town along the road to Pomona. The clay
is a reddish residual clay resulting from the decomposition of gneissic
rock, and opened up to a depth of 8 feet. This material is somewhat
more sandy in portions of the bank, but all of it is soft. A sample of
this clay was found to slake easily to its component grains. It required
28^ of water to produce a workable mass, which shrunk 9$ in drying
and 6$ in burning, making a total shrinkage of 15$. This paste was
moderately plastic. Air-dried briquettes of the clay had an average ten-
sile strength of 85 lbs. per square inch and a maximum of 96 lbs. per
square inch. Incipient fusion occurs at 2050° F., vitrification at 2250°
F., and viscosity at 2450° F. The clay burns to a red body.
Its composition is as follows:
Analysis of Greensboro Brick & Tile Co's. Clay {No. 21).
Moisture 1.64
Silica (total) 56.81
Alumina 20.62
Ferric oxide 6.13
Lime 65
Magnesia 58
Alkalies 4.47
Water (loss on ignition) S.60
Total 99.50
Clay substance 5S.S5
Free sand 40.65
Total fluxes 11.83
Specific gravity 2.44
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 115
The high per cent, of alkalies is evidently due to much undecom-
posed feldspar. A very good building brick is made from this clay.
The plant includes a pair of rolls, Freese disintegrator and Treese side-
cut auger machine. The brick are dried on a brick floor heated by hot
air passing through flues underneath. They have three Morrison kilns
in which soft coal is used. Re-pressing has been tried with fair results.
Dean's brickyard is on the southern side of town, and the clay is very
similar to that at the Greensboro Brick and Tile Company's yard.
It is a lean, gritty clay, with abundant grains of quartz, feldspar and
mica. In water it slakes easily to its component grains.
It absorbed 28$ of water in being worked into a paste, which shrunk
lOfc in drying and 6$ in burning, giving a total shrinkage of 16$. The
average tensile strength of air-dried briquettes was 66 lbs. per square
inch, while the maximum was 77 lbs. per square inch. Incipient fusion
occurred at 2100° F., vitrification at 2300° F., and viscosity at 2400° F.
The clay burns red. Its composition is shown by the following analysis:
Analysis of Dean's Bruk-clay {No. 30) pit, Greensboro .
Moisture 1.90
Silica (total) 59.27
Alumina 22.31
Ferric oxide 6.69
Lime 25
Magnesia 13
Alkalies 90
Water (loss on ignition) 9.00
Total 100.45
Clay substance 67.20
Free sand 33.25
Fluxes 7.97
Specific gravity 2.46
This clay is used for the manufacture of common brick. It is tem-
pered in a ring pit, molded by hand, dried in the sun, and burned in
scove kilns. The product is burned little beyond incipient fusion.
Watson's brickyard uses the same clay and methods as are used at
Dean's yard, just described.
Kirkpatrick's brickyard is situated along North Buffalo creek, and
the clay is a portion of the deposit to be found more or less continuously
along the creek all the way up to Pomona. It i< a gray, gritty clay,
dense and tough, and slakes slowly to irregular granules.
It required the addition of 3(K of water to make ;i workable paste,
which shrunk 11$ in drying and :>'< in burning, giving a total shrinkage
of lQfc. Air-dried briquettes of the very plastic paste had an average
116 CLAY DEPOSITS IN NORTH CAROLINA.
tensile strength of 220 lbs. per sqnare inch with a maximum of 232 lbs.
per square inch. Incipient fusion occurs at 1900° F., vitrification at
2100° F., and viscosity at 2300° F. It burns to a dense red body, but
requires slow heating. The composition is indicated by the following
analysis :
Analysis of Kirkpatrick' s Brick-clay {No. 31), Greensboro.
Moisture 1.50
Silica (total) 69.70
AlumiDa 12.87
Ferric oxide 6.13
Lime 2.55
Magnesia 57
Alkalies 2.79
Water (loss on ignition) 4.08
Total 100.19
Clay substance 35.27
Free sand 64.92
Fluxes 12.04
Specific gravity 2.48
The clay is discharged directly into a steel end-cut auger machine,
heated on drying floors, and burned in scove kilns.
CLAY IN HALIFAX COUNTY.
Near Roanoke Rapids. — There has been considerable demand for
brick at this locality for use in the construction of large cotton mills
being erected at this point. The clays used occur along or near the
Roanoke river, a few hundred yards south of the cotton mills. The
section is in general as follows:
Yellowish sandy clay (sample No. 1) 2 to 5 ft.
Plastic clay (exposed) (sample No. 2) 6 to S ft.
This upper sandy clay is coarse-grained and contains numerous small
concretions of sand cemented by limonite. A sample of this upper clay
was tested with the following results: The sandy, moderatelv coarse-
grained yellow clay slaked extremely slowly on account of its density.
It required 25^ of water to produce a workable paste, which to the feel
was very lean. This paste shrunk Sfc in drying and 5$ in burning,
giving a total shrinkage of 13#. Air-dried briquettes of the mud had
an average tensile strength of 46 lbs. per square inch and a maximum
strength of 50 lbs. per square inch. Incipient fusion occurred at 1900°
F., vitrification at 2050° F., and viscosity at 2250° F.
At 1900° the clay burned to a reddish, porous body, but at 2050° it
s
BRICK-CLAY DEPOSITS EN NORTH CAROLINA. 117
was fairly dense, but deep reddish brown. The little ferruginous con-
cretions fuse to black spots in burning.
The following is the composition of this upper sandy day.
Analysis of upper sandy Clay (JVo. 1), Roanoke Rapids.
Moisture 1.63
Silica (total) 67.55
Alumina 13.16
Ferric oxide S.54
Lime 17
Magnesia 28
Alkalies 2.65
Water (loss on ignition) 5.08
Total 99.06
Clay substance 41.98
Free sand 57.08
Total fluxes 11.64
Specific gravity 2.39
The insoluble residue (" free sand ") in the above indicates the sandy
character of the clay and the reason of its leanness and low tensile
strength.
The underlying clay is less sandy and feels far more plastic. It con-
tains a few small mica scales. It slakes moderately fast to grains of
small size, and is not a very dense clay. The following description ap-
plies to the part of this lower clay (6 to 8 feet thick) exposed and used
in the pits at Roanoke Rapids, and here designated the middle clay
(sample No. 2):
It required 26.5^ of water to make a workable mass, which was highly
plastic. This mud shrunk 10$ in drying and an additional 5$ in burn-
ing, giving a total shrinkage of 15v. Air-dried briquettes made from
this paste exhibited an average tensile strength of 151 pounds per square
inch and a maximum of 168 pounds per square inch. Incipient fusion
occurs at 1900° F., vitrification at 2050° F., and viscosity at 2250° F.
The clay burns to a red body, much smoother than the preceding sample.
The increased plasticity is very noticeable, and due no doubt in part
to the smaller quantity of sand present and perhaps greater fineness of
the grains.
The following is the composition of the clay:
Analysis of the middle Brick-clay [No. 2), Roanoke Rapids.
Moisture 2.45
Silica (total) 65.58
Alumina 11.04
Ferric oxide 5.76
Lime ' -
Magnesia -s
118 CLAY DEPOSITS IN NORTH CAROLINA.
Alkalies 2.30
Water (loss on ignition) 5.58
Total 99.71
Clay substance 56.70
Free sand 31.50
Total fluxes 9.06
Specific gravity 2.59
Another sample (No. 3) of this lower clay, and here designated the
under clay, represents its lower portion, extending for several feet
below the level of the present floor of the brickyard at Roanoke Rapids,
and was collected to show the uniformity of this lower clay. Its gen-
eral character may be seen from the following description :
To the feel the lower sample of the under clay was about the same
in grittiness and fineness of grain as the upper part of this lower clay
stratum (No. 2), but the plasticity was seemingly greater. The clay
slaked rather readily to irregular granules, requiring 26$ of water added
to it in order to produce a workable paste, which was very plastic. This
paste shrank 10.6^ in drying and 5$ in burning, making a total shrink-
age of 15.6/1 The average tensile strength of the air-dried briquettes
was 206 lbs. per square inch, and the maximum strength 218 lbs. per
square inch.
Incipient fusion occurred at 1900° F., vitrification at 2050° I\, and
viscosity at 2250° F. The clay burned to a dense red body. Its com-
position is as follows:
Analysis of the under Brick-clay (No. 3), Roanoke Rapids.
Moisture 2.05
Silica (total) 59.68
Alumina 16.09
Ferric oxide 8.91
Lime 1.35
MagDesia 14
Alkalies 3.24
Water (loss on ignition) 6.33
/•
Total 97.79
Clay substance 42.2S
Free sand 39.S2
Total fluxes 13.24
Specific gravity 2.56
A comparison of the three clays sampled from this locality is worth
while. The last two, it will be noticed, possess a much greater plas-
ticity than the first, a greater tensile strength, and burn to a denser and
harder body at the same temperature than the first one does.
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 119
The under bed of this bank is far better suited to the manufacture
•of good brick than the upper sandy one; and a mixture of the two
would be better than using either the upper sandy clay alone or this
with sand added. The latter only helps to make the brick more porous
in view of its naturally sandy condition.
Near Weldon. — Similar clays to those at Roanoke Rapids are dug
along the railroad south of the depot; they are used for the manufacture
of common building brick.
Near Halifax also there are extensive beds of clay, but these, like
those at Weldon, could not be carefully examined in time for the
present report.
CLAY IN HARNETT COUNTY.
Near Spout Springs. — There are three cuts along the line of the
C. F. & Y. V. R. R. between Fayetteville and Spout Springs in which
there are exposed considerable quantities of a purplish clay. The first
of these is between the 92d and 93d mile post,1 and just N.W. of
McClenehan cut. The clay comes up in a low, dome-shaped mass,
showing a maximum thickness of 8 feet above the roadbed. There is
very little sand covering, and the clay is remarkably homogeneous in
its character. An examination of a sample from this cut showed it to
be a fine-grained, tough clay, even grained and with conchoidal frac-
ture. It slakes easily in water to grains. It required 35$ of water to
give a workable paste that was only slightly plastic but smooth. This
paste shrank 10$ in drying and 4$ in burning, giving a total shrinkage
of 14$. Air-dried briquettes made from this paste had an average ten-
sile strength of 27 lbs. per square inch and a maximum of 31 lbs. per
square inch.
Incipient fusion occurred at 1950° F., vitrification at 2150° F., and
viscosity at 2350° F. The clay burns to a buff at 2000° F., but with
more firing turns red. The composition of it is as follows:
Analysis of Brick-clay {No. 16), C. F. & Y. V. R. R., 92-93 mile post.
Moisture 1.42
Silica (total) 64.16
Alumina -1.71
Ferric oxide 1.58
Ferrous oxide 1.08
Lime 23
Magnesia 1 5
Alkalies 77
Water (loss on ignition) 8.30
Total 99.40
1 Measuring from Wilmington.
£
120 CLAY DEPOSITS IN NORTH CAROLINA.
Clay substance 58.55
Free sand 40.90
Total fluxes 3.81
Specific gravity 2.43
The second cut is at the 100-mile post, and the clay shows nine feet
of thickness.
Here, again, the clay (No. 17) is very fine-grained and homogeneous,
hut not quite so gritty as the preceding. It slakes just the same, and
required 32^ of water to make a workable but rather lean paste, which
shrunk 8$ in drying and 6^ in burning, or a total of 14=fc. The air-dried
briquettes had an average tensile strength of 24 lbs. per square inch and
a maximum of 29 lbs. per square inch. Incipient fusion occurred at
1950° F., vitrification at 2150° F., and viscosity at 2350° F. The clay
burns to a smooth, red body. Its composition is:
Analysis of Brick-clay {No. 17), C. F. & Y. V. R,. R., at 100 mile pout.
Moisture , 1.35
Silica (total) 50.68
Alumina 32.51
Ferric oxide 3.06
Lime 30
Magnesia 02
Alkalies 58
Water (loss on ignition) 11.08
Total 99.58
Clay substance 83.43
Free sand 16.15
Total fluxes 3.96
Specific gravity 2.53
The third cut along the railroad is a half mile southeast of Spout
Springs and shows fully 12 feet of this clay; while a fourth exposure
of it is in the cut just northwest of Spout Springs station (Plate XII,
fig. 2).
The clay exposed in this last mentioned cut possesses the same homo-
geneous, tough, fine-grained character as those just described. A sample
(Xo. 18) tested from this place slaked quickly and, when mixed with
35$ of water, gave a workable, lean, smooth mass that shrunk 9$ in
drying and 8^ in burning, a total shrinkage of 17$. The air-dried,
briquettes made from this paste had an exceedingly low tensile strength,
19 lbs. per square inch on the average with a maximum of 25 lbs. per
square inch. Incipient fusion occurred at 2000° F., vitrification at
2200° F., and viscosity at 2400°. The clay burns to a red-gray dense
body. The following is the composition of this clay:
N. C. GEOLOGICAL SURVEY.
BULLETIN 13, PLATE XII.
FIG. 1.— BRICKWORKS OF CARTER AND SHEPARD, BETHANIA.
(See page 111.)
FIG. 2.— CLAY DEPOSIT IN RAILWAY CUT, SPOUT SPRINGS, C. F. & Y. V. RAILROAD.
*m
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 121
Analysis of Clay {No. 18), C. F. & Y. V. R. R., Spout Springs station.
Moisture 1.05
Silica (total) 53.65
Alumina 28.66
Ferric oxide 4.50
Lime 10
Magnesia 1.35
Alkalies 29
Water (loss on ignition) 10.79
Total 100.39
Clay substance 73.77
Free sand 26.65
Total fluxes 6.24
Specific gravity 2.41
CLAY IN JACKSON COUNTY.
^Tear Sylva. — Along the road south of Sylva and three-quarters of a
mile from the kaolin washing works is considerable outcropping of gray
clay (No. 55) with much quartz. There is also an abundance of mica
scales in it. The clay which has been experimented with in the hopes
that a ball-clay might be obtained from it by washing, contains too much
ferric oxide. Its chief application lies in the manufacture of pressed
brick, or to mix with a more plastic clay for vitrified wares, such as
sewer-pipe or possibly paving brick.
The clay, which varies from coarse to fine, contains abundant grains
of quartz as well as scales of mica. It slakes slowly to irregular grains.
The addition of 2Sr/> of water gave a tough but stiff mass, which to the
feel was gritty and plastic. The shrinkage in drying was 9$ and in
burning 5$, giving a total shrinkage of 14^. The average tensile
strength of the air-dried briquettes was 58 lbs. per square inch, with a
maximum of 67 lbs. Incipient fusion occurred at 2100° F., vitrifica-
tion at 2300° F., and viscosity at 2500° F.
The clay burns red. Its composition is as follows:
Analysis of Brick-clay {JSfo. 55), near Sylva.
Moisture 45
Silica (total) 66.70
Alumina 19.75
Ferric oxide 3.25
Lime 45
Magnesia 16
Alkalies 2.12
Water (loss on ignition) 6.65
Total 99.53
122 CLAY DEPOSITS IN NORTH CAROLINA.
Clay substance 47.28
Free sand 52.25
Total fluxes 6.08
Specific gravity 2.59
CLAY IN MARTIN COUNTY.
Near Williamston. — Two samples of residual clay from this locality
were submitted to the Geological Survey for testing. The first (No. 66)
was a moderately coarse-grained clay which slaked easily to irregular
grains. The addition of 40$ of water was required to give a workable
mass that to the feel was lean and gritty. This mud shrunk 13$ in
drying and 3$ in burning, giving a total shrinkage of 16$. Care had
to be .exercised in drying to prevent it from cracking. The average
tensile strength of the air-dried briquettes was 67 lbs. per square inch,
while the maximum was 78 lbs. Incipient fusion occurs at 2000° F..
vitrification at 2150° F., and viscosity at 2300 = F. The clay burns
red at incipient fusion, but above that the color deepens rapidly.
The second sample was similar in appearance to the first one, and,
like it, slaked easily to its component grains. The addition of 29$ of
water gave a workable but lean, sticky mass, which shrunk 10$ in dry-
ing and 2$ in burning, giving a total shrinkage of 12$. The air-dried
briquettes had an average tensile strength of 71 lbs. per square inch
with a maximum of 100 lbs. Incipient fusion occurred at 2000° F.,
vitrification at 2150° F., and viscosity at 2200° F.
The clay burns red at 2000° F., but the color becomes much deeper
with harder firing.
This clay cracks less than the previous one in drying, for the shrink-
age is less.
Both these clays illustrate the lean character and low-binding quali-
ties of some clays, both sedimentary and residual. Their porous
nature and avidity for water cause them to soak up large quantities of it,
and the consequent expulsion of this water brings about excessive shrink-
age and necessitates very slow drying. The only remedy in such cases
is the admixture with these lean, porous clays of other clays that are
more compact and have better binding qualities.
CLAY IN MECKLENBURG COUNTY.
Near Charlotte. — The region in the vicinity of Charlotte is under-
lain by sedimentary clays in the hollows, and residual clays on the
hills. While those in the hollows are largely composed of the wash
from the hills, still, on account of the sorting and elimination of coarse
particles which follow as a result of the washing, the lowland deposits
are smoother and more plastic.
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 123
One of the latter class is near D. K. Cecil's yard on Trade street at
the east edge of the town.
The section of this clay bank shows the following:
Loam (soil) 12-18 inches.
Clay 8 feet.
Sand
The clay is gray, mottled with iron stains, fine-grained, fairly smooth.
There is no mica apparent. It slakes quickly.
The addition of 25.8^ of water gave a moderately plastic paste with
somewhat gritty feel. This paste shrunk Qfo in drying and 6$ in burn-
ing, giving a total shrinkage of 12$. The average tensile strength of
air-dried briquettes was 88 lbs. per square inch with a maximum
strength of 95 lbs. per square inch.
Incipient fusion occurs at 1850° F., vitrification at 2050° F., and
viscosity at 2250° F.
The clay burns to a red, fairly smooth body. Its composition is as
follows :
Analysis of B. K. Cecil's Brick- clay (N~o. 39), Charlotte.
Moisture 1.35
Silica (total) 68.35
Alumina 13.13
Ferric oxide 6.87
Lime 2.10
Magnesia 32
Alkalies 2.86
Water (loss on ignition) 5.20
Total 100.18
Clay substance 38.73
Free sand 61.45
Total fluxes 12.15
Specific gravity 2.68
Mr. Cecil uses the clay for the manufacture of common brick. The
clay is molded in an auger side-cut machine, dried on pallets and burned
in scove kilns. The product is usually a hard, dense brick.
At Houser's yard, one-quarter mile from Cecil's, there is a similar
deposit of sedimentary clay. It contains an abundance of small quartz
grains. The bricks are barely burned to incipient fusion. Houser's
plant includes a pair of rolls, Brewer side-cut machine, and pallet racks.
The clay from this yard was not tested. It is situated along the
same stream as Cecil's deposit.
At F. M. Sassamon's brickyard, two miles northwest of Charlotte,
121 CLAY DEPOSITS IN NORTH CAROLINA.
the clay lies in a hollow and covers a number of acres. Its exact thick-
ness is not known, but it is not less than six feet. A sample of this clay
was examined and found to be a somewhat coarse-grained, porons clay.
It slakes moderately fast to fine aluminous mud and granules. The
addition of 35fc> of water gave a plastic mass, which shrunk 13.3$ in
drying and 8fo in burning, giving a total shrinkage of 21.3$. The dry-
ing could not be hurried, as otherwise cracking resulted. The average
tensile strength of the air-dried briquettes was 105 lbs. per square inch
with a maximum of 125 lbs.
Incipient fusion occurred at 1950° F., vitrification at 2100' I\, and
viscosity at 2250° F. The clay burns red.
Its composition is as follows:
Analysis of F. M. Sassamon's Brick clay (Wo 42). Charlotte.
Moisture 1.27
Silica (total) » . 65.95
Alumina 14.67
Ferric oxide 7.61
Lime 2.57
Magnesia 25
Alkalies 2.55
Water (loss on ignition) 5.52
Total 100.39
Clay substance 43.84
Free sand 56.45
Fluxes 12.98
Specific gravity 2.60
Shuman operates a deposit (No. 11) just north of Charlotte, which is
a mixture of sedimentary clay and residuum. It is about 9 feet thick
as exposed, and varies from a sandy clay to a fat, tough one.
Most of it is coarse-grained, gritty, and slakes slowly but completely.
The clay required the addition of 35$ of water to give a workable,
though lean mass. Its porous nature permitted rapid drying, and it
shrunk 5$ in doing so. The shrinkage in burning was 4$, giving a
total shrinkage of 9$. Air-dried briquettes had an average tensile
strength of 26 lbs. per square inch and a maximum of 2S lbs. Incipi-
ent fusion occurred at 2100° F., vitrification at 2200° T., and viscosity
at 2300° F. The clay burns to a reddish brick.
The composition of it is as follows:
Analysis of F. W. Shuman' s Brick-clay (No. 41), Charlotte.
Moisture 7.10
Silica 59.15
Alumina 18.36
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 125
Ferric oxide 6.04
Lime 20
Magnesia 34
Alkalies 1.72
Water (loss on ignition) 7.47
Total 100.38
Free sand 39.50
Total fluxes 8.30
Specific gravity 2.44
J. Asbury lias a brickyard about one and a half miles north of the
town. The section at the clay bank shows four feet of red clay (sample
No. 62) and under this six feet of very plastic blue clay. The addition
of 25$ of water gave a workable paste of good plasticity.
This paste shrank 7$ in drying and 5$ in burning. The average
tensile strength of the air-dried briquettes was 60 lbs. per square inch
with a maximum of 72 lbs. per square inch. Incipient fusion occurred
at 1900° F., vitrification at 2100° F., and viscosity at 2300° F.
The clay burns red. Its analysis shows the following:
Analysis of J. Asbury's upper red Brick-clay (No. 62), Charlotte.
Moisture 63
Silica (total) 60.33
Alumina 18.57
Ferric oxide 10.03
Lime 20
Magnesia 14
Alkalies 55
Water (loss on ignition) 7,83
Total 98.28
Clay substance 56.23
Free sand 42.05
Total fluxes 10.02
Specific gravity 2.60
CLAY IN RICHMOND COUNTY.
Near Rockingham. — A red, coarse-grained, sedimentary clay (Xo.
23) occurs at Roberdell, four miles north of Rockingham. The upper
portion of the deposit is somewhat sandy. In practice the bricks seem
to shrink considerably in burning and also to crack, but they burn to
a deep red color. The clejDosit is owned by R. L. Steele.
A sample of this clay slaked slowly to grains ?V to T\T in. diameter.
It required 26$ of water to make a workable paste which shrunk CVr
in drying and 8$ in burning, making a total shrinkage of 14$. It
required slow heating to avoid cracking. The average tensile strength
126 CLAY DEPOSITS IN NORTH CAROLINA.
of air-dried briquettes made from this paste was 133 lbs. per square
inch with a maximum of 154 lbs. Incipient fusion occurs at 2000° F.,
vitrification at 2200° F., viscosity at 2400° F. The clay bums to a deep
red. It is not fine or smooth enough to be used for pottery. The
composition of the clay is as follows:
Analysis of Brick clay {No. 23), 4 miles N. of Rockingham.
Moisture 1.98
Silica (total) 59.59
Alumina 22.07
Ferric oxide 4.27
Lime 65
Magnesia 49
Alkalies 2.70
Water (loss on ignition) 7.53
Total 99.28
Clay substance 51.63
Free sand 47.65
Fluxes 8.11
Specific gravity 2.54
CLAY IN ROBESON COUNTY.
^Near Red Springs. — Five or six brickyards have been in operation
at this locality for some years. The flat, wooded region around the
town is underlain by abundance of yellowish, coarse-grained, sandy clay
of extreme leanness. The abundant sand grains are nearly all pure
quartz.
The poor quality of this material is evident on sight, but a sample
(No. 19) was tested in order to demonstrate this fact, for there is a
tendency among many small manufacturers to use very sandy clay, as it
molds easier.
The examination showed it to be a porous, coarse clay, slaking fairly
fast in water. It required 17$ of water to make a workable mass
which was extremely lean. This paste shrank 8.8$ in drying and 4$
in burning, giving a total shrinkage of 12.8$. Air-dried briquettes
had an average tensile strength of 41 lbs. per square inch and a max-
imum of 51 lbs. Incipient fusion occurred at 2100° F., vitrification at
2250° F., viscosity at 2400° F. At 2100° F. it burns red, but is still
porous and weak.
The composition of the clay is as follows:
Analysis of Brick-clay {No. 19), Red Springs.
Moisture 1.09
Silica (total) 78.16
Alumina 8.26
Ferric oxide 4.09
Lime 40
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 127
Magnesia 22
Alkalies 2.91
Water (loss on ignition) 4.14
Total 99.27
Clay substance 15.22
Free sand 74.05
Total fluxes 7.62
Specific gravity 2.60
The chemical analysis indicates the large percentage of sand in the
clay, and the quantity and coarseness of this sand makes the clay too
lean. On account of this very high percentage of sand in the clay
considerable heat is required to make a hard brick of it.
None of the clay pits at Red Springs are deep, and it is not known
whether the clay increases with depth, but if it does the product would
be of much better quality by using it.
CLAY IN ROWAN COUNTY.
Near Salisbury. — Half a mile south of the station is an area of
swamp land underlain by considerable clay, mostly of a plastic nature.
The section shows 6 feet of clay underlain by sand, and the tract is
about an eighth of a mile long. There are occasional iron streaks in
the clay, but these are mostly confined to sandy spots. A sample of
this clay (No. 48) which was tested showed it to be medium-grained
with considerable grittiness. It slaked slowly and required the addi-
tion of 28$ of water to give a workable mixture which was very plastic.
This mass shrunk 8.5$ in drying and 5.5$ in burning, giving a total
shrinkage of 14$. The average tensile strength of air-dried briquettes
was 129 lbs. per square inch with a maximum of 144 lbs. Incipient
fusion occurs at 1850° F., vitrification at 2050° F., and viscosity at
2250° F.
The clay burns to a red color. Its composition is as follows:
Analysis of Brick-clay {No. 48), south side of Salisbury.
Moisture 1.91
Silica (total) 69.89
Alumina 15.31
Ferric oxide 4.39
Lime 55
Magnesia 16
Alkalies . .70
Water (loss on ignition) 6.37
Total 99.2S
Clay substance 47.3S
Free sand 51.90
Total fluxes 5.80
128 CLAY DEPOSITS IN NORTH CAROLINA.
This clay has been used at D. K. Cecil's brickyard for five years.
The clay receives no tempering, but is charged directly into a small
auger machine with a three-stream die. The bricks are dried in the
sun and burned in scove kilns.
The quality of the brick admits of much improvement, and the
quality of the clay warrants it.
CLAY IN SURRY COUNTY.
!Neae Elkin. — An opening has been made one mile west of town
along the railroad and on the property of the Pomona SeAver-pipe Co.,
and exposes the same yellowish clay as that noted at \Yilkesboro. The
clay is 8-10 feet deep and underlain by sand and coarse pebbles.
The clay itself (No. 38a) is fine-grained and contains numerous small
mica scales and fine grit. It slakes somewhat slowly to its component
grains. The addition of 16$ of water gave a workable but somewhat
lean mud, which shrank 7$ in drying and 9$ in burning. The average
tensile strength of the air-dried briquettes was 69 lbs. per square inch
and the maximum was 73 lbs.
Incipient fusion occurred at 1900° E., vitrification at 2100° E., vis-
cosity at 2300° 1". The clay burns red and gets very deep red or
brown on vitrifying.
The analysis of it yielded the following:
Analysis of Brick-clay (No. 38a), Pomona Co.'s bank, FAkin.
Moisture 90
Silica (total) 59.4S
Alumina 19.24
Ferric oxide 8.26
Lime 60
Magnesia 1.01
Alkalies 3.76
Water (loss on ignition) 6.41
Total 99.66
Clay substance 49.21
Free sand 50.35
Total fluxes 13.53
Specific gravity 2.59
Mixed with some more plastic clay, such as that used for sewer-pipe
at Pomona, this clay might possibly be used for the manufacture of
paving brick.
There are numerous points between Elkin and ISTorth ^Yilkesboro
where the cutting of gullies in the terrace has exposed this yellow clay.
The clay used at the brickyards just east and west of Elkin is resid-
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 129
ual material of uncertain character and not associated with that down
in the valley bottom.
"While these yellow clays of the lowlands would doubtless make a
good smooth building brick by the soft-mud process, it is doubtful if
they would work in an auger machine, and probably refuse to issue
from the die without tearing, for there is little bond between the clay
particles. In mixing, it also shows slight tendency by itself towards
the development of a laminated structure.
CLAY IN UNION COUNTY.
Near Monroe. — The lowlands southwest of the depot are underlain
by an abundance of blue clay, and though only about 6 feet deep,
still it covers a considerable area. As the creek which flows through the
lowland is approached the clay becomes more sandy.
A sample of this clay (No. 40) was found to be fairly smooth and
slaked slowly but rather completely. It required the addition of 23$
of water to produce a workable mass that was very plastic and that
shrank 6$ in drying and 3$ in burning, giving a total shrinkage of 9$.
Incipient fusion occurred at 1950° F., vitrification at 2150° F., and
viscosity at 2350° F. The clay burns red, but underburning produces
a yellowish red.
For a plastic clay the shrinkage is quite low.
The average tensile strength of the air-dried briquettes was 124 lbs.
per square inch with a maximum of 148 lbs. per square inch.
It is probable that some of the finer portions of this clay bed could be
used for the lower grades of stoneware.
The composition of the clay is as follows, the sample (No. 40) coining
from J. T. Shute's clay bank:
Analysis of Brick-clay {No. 40), Shute's clay bank, Monroe.
Moisture 1.65
Silica (total) 76.60
Alumina 9.98
Ferric oxide 4.46
Lime 30
Magnesia 27
Alkalies- 2.25
Water (loss on ignition) 4.30
Total 99.81
Clay substance 34.26
Free sand 65.55
Total fluxes 7.28
The clay contains a small amount of organic matter and is a good
illustration of the combination of low alumina and marked plasticity.
9
130 CLAY DEPOSITS IN NORTH CAROLINA.
J. T. Shute manufactures common brick from the clay at Monroe.
The clay makes a very fair product, but has to be burned carefully.
The bricks are molded in a Brewer auger machine with vertical pug-
ging cylinder attached.
CLAY IN WAKE COUNTY.
Near Raleigh. — Much clay of very plastic nature underlies the
bottom lands north and east of the city. It has thus far been worked
only for building brick, although promising experiments have been
made looking towards its utilization for the coarser grades of pottery.
A small deposit of considerable plasticity underlies the low ground
between Caraleigh Mills and the phosphate mill southeast of town.
This deposit is not nearly so extensive, however, as that north of the
town in the lowland along the Neuse river.
The clay used at the penitentiary is obtained from the lowland
southeast of the city. The upper two feet are a yellowish sandy clay,
but under this is a much fatter gray clay possessing considerable plas-
ticity to the feel, and frequently comparatively free from grit in the
form of coarse sand grains. A small amount of organic matter is
present. It is a tough, fairly compact clay which slakes rather fast to
grains and granules. It required the addition of 25$ of water to make a
workable mass, which shrunk 9.3$ in drying and 4$ in burning, giving a
total shrinkage of 13.3$. Air-dried briquettes made from this mixture
had an average tensile strength of 123 lbs. per square inch and a max-
imum tensile strength of 144 lbs. per square inch. Incipient fusion
occurred at 2000° F., vitrification at 2150° F., and viscosity at 2300° F.
The clay burns to a red, which increases in depth of color when the
clay is burned to vitrification. The composition of this clay is shown
by the following:
Analysis of Brick-clay {No. 23), Penitentiary Yard, Raleigh.
Moisture 1.60
Silica (total) 70.03
Alumina 15.64
Ferric oxide 2.SS
Lime 80
Magnesia 57
Alkalies 1.47
Water (loss on ignition) 6.37
Total 99.36
Free sand 54.55
Clay substance 44. SI
Total fluxes 5.72
Specific gravity 2.54
.
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 131
The low percentage of total fluxes accounts partly for the fusion
point being 2300°.
It is probable that some of the smoother portions of this clay deposit
would work very well for common stoneware.
The clay underlying A. Ii. Green's land on the north side of the
river is less gritty.
The clay-working industry around Raleigh is confined to the manu-
facture of common brick. These are made by the Caraleigh Mills
Company and the North Carolina State Penitentiary. Both used hand-
molds and dry the bricks in the sun and burn them in up-draft, open-
top kilns. Considering the method of molding, the clay makes a very
good red building brick. Steam-power machinery would no doubt
greatly increase the value of the product. Re-pressing has been tried
with considerable success, and brick thus treated were used in the gov-
ernor's mansion at Raleigh.
CLAY IN WAYNE COUNTY.
!STear Goldsboro. — There are extensive beds of sedimentary clay
underlying the lowlands southeast of the town. At the Goldsboro Brick
and Tile Company, or Grant's yard, one mile southwest of Goldsboro,
quite a large surface has been worked over in obtaining its clay, in order
to use the clay at the surface, which is far more sandy but of good plas-
ticity. The exact depth of the clay is not known.
A track runs along the central portion of the excavation, and the clay
is dug by means of scrapers and brought to cars on the track. These
cars are hauled to the foot of an incline and drawn up by cable to the
second floor of the works, where the clay is discharged. It passes first
through a pair of rolls and then to the pugmill, from which it is dis-
charged into a Kell's auger machine. The brick are side-cut, and the
cutting table is operated by hand power. Ten brick are cut at a time
and discharged from the cutting table on to a pallet. The bricks are
carried directly to the drying chambers. These consist of a series of
cupboards, across which runs a series of parallel steam-pipes, which
serve as a shelving. The pallets are shoved endwise into each cham-
ber. In the practice of this method a considerable per cent, of the
brick may be lost when, in pushing the pallet into the chamber, the
" off-bearer " pushes against the end brick instead of the pallet and
crushes the former all out of shape. The drying requires three days
when heat is applied during the daytime only. The yard is also
equipped with pallet racks.
Burning is done in up-draft kilns with a capacity of about 200,000
each. The bricks are burned to a light red.
The upper part of the clay consists of tough, light-blue plastic clay
132 CLAY DEPOSITS IX NORTH CAROLINA.
with much intermixed sand. The use of the rolls is supposed to break
up these lighter-colored lumps of clay, but it does not always do so
entirely, as can be seen from an inspection of the burned brick, the
lighter-colored lumps of the clay occasionally showing within. A wet
pan would probably give better results. The mixture of the sandy and
tough clay gives the best results and makes a good brick.
A sample of this clay was tested. It was a coarse to fine-grained
clay (No. 7) that slaked irregularly. The addition of 33 per cent,
of water gave a fairly plastic and somewhat tough mass, which shrunk
8$ in drying and 6$ in burning, giving a total shrinkage of 14X The
air-dried briquettes had an average tensile strength of 65 lbs. per square
inch and a maximum tensile strength of 74 lbs. per square inch. Incipi-
ent fusion occurs at 1900° F., vitrification at 2100° T., and viscosity at
2300° F.
This kind of clay should be thoroughly mixed, and when so treated
it burns to a uniform attractive red, but if the clay be not well mixed
the lumps of tougher clay are plainly seen if the temperature is raised
rapidly so that the iron in them does not get a chance to become thor-
oughly oxidized. The composition of this clay mixture is as follows:
Analysis of Gt ant's Brick-zlay (No. 7), Goldsboro.
Moisture 1.58
Silica (total) 66.05
Alumina 17.81
Ferric oxide 6.69
Lime 30
Magnesia 25
Alkalies 1.04
Water (loss on ignition) 6.32
Total 100.04
Clay substance 51.47
Total fluxes 7.76
Free sand 48.05
Specific gravity 2.53
Near the factory of the Goldsboro Brick and Tile Company is a con-
siderable quantity of tough clay which is called " fire-clay," but which
is not a true fire-clay as that term is generally used. This clay simply
requires a little more heat in burning the brick than the clay usually
employed.
A sample of this " fire-clay " showed it to be a tough, plastic, fine-
grained clay with scattered scales of mica, It slakes moderately fast
to a mixture of fine powder and small angular quartz grains. The addi-
tion of 25$ of water gave a plastic, workable paste that shrunk 8.5$ in
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 133
drying and an additional 5$ in burning, giving a total shrinkage of
13.5$. The air-dried briquettes made from this paste had an average
tensile strength of 107 lbs. per square inch and a maximum of 125 lbs.
per square inch. Incipient fusion occurs at 1950° F., vitrification at
2150° F., and viscosity at 2300° F. The clay burns to a deep red,
tough, dense body, and might be worked for stoneware.
The following analysis shows its composition:
Analysis of Grant's " Fire-clay " (No. 9), Goldsboro.
Moisture 1.12
Silica (total) 65.95
Alumina 13.51
Ferric oxide 4.64
Lime 35
Magnesia 36
Alkalies 2.82
Water (loss on ignition) 11.58
Total 100.33
Clay substance 49.63
Total fluxes 8.17
Free sand 50.70
Specific gravity , .• 2.55
On account of the high percentage of combined water the clay had to
be heated very slowly to prevent cracking.
II. Weil & Bros.7 yard and clay bank are about a mile and a half
southwest of Goldsboro. Their clay deposit, which is an extension of
that of the Goldsboro Brick & Tile Co., contains a considerable quan-
tity of plastic clay. This is 8 feet thick in places, and towards the
surface becomes mixed with sand. The clay is molded by hand and
pugged in a vertical mill operated by horse-power. The water-smoking
and burning is done in the rather short time of five days.
A sample of the plastic clay (No. 8) tested showed it to be moder-
ately fine with considerable grit and mica scales. The clay is some-
what porous but tough, and slakes slowly to irregular grains. The
addition of 25$ of water gave a workable mixture of fair plasticity. It
shrunk 8.3$ in drying and 3$ in burning, giving a total shrinkage of
11.3$. The air-dried briquettes made from the worked-up paste had
an average tensile strength of 85 lbs. per square inch and a maximum
strength of 102 lbs. per square inch. Incipient fusion occurs at 1900°
F., vitrification at 2100° F., and viscosity at 2300° F.
The clay burns to a red color. Underburning and imperfect oxida-
tion make the brick grayish-red or brown, and porous.
The composition of the clay is as follows:
134 CLAY DEPOSITS IN NORTH CAROLINA.
Analysis of Weil's Brick-clay (No. 8), Ooldsboro.
Moisture 1.85
Silica (total) 67.90
Alumina 18.74
Ferric oxide 3.1G
Lime 40
Magnesia 45
Alkalies 1.85
Water (loss on ignition) 6.03
Total 100.38
Clay substance 46.23
Total fluxes 5.86
Free sand 54.15
Specific gravity 2.57
CLAY IN WILKES COUNTY.
Near Wilkesboro. — The valley of the Yadkin river at this locality
is nearly three-quarters of a mile wide, and its broad, flat bottom is
underlain by an abundance of clay.
At D. SmoaWs yard, on the south side of the river just west of the
iron bridge, the clay is said to be 13 feet thick and to be underlain by
gravel and sand. As the river is approached, the surface sand increases
in depth. The clay is claimed to improve greatly with the depth, so
a sample (No. 37) was taken from the bottom of the deposit and one
(No. 36) representing the average material now used.
The latter (No. 36) is a fine-grained, yellowish clay with numerous
very small mica scales. It slakes quite rapidly and completely to fine
grains. The addition of 25^ of water gave a workable but lean paste.
This paste shrunk 5^ in drying and 10$ in burning, giving a total
shrinkage of 15$. The average tensile strength of the air-dried bri-
quettes was 74 lbs. per square inch with a maximum of 76 lbs. per
square inch.
Incipient fusion occurs at 1900° F., vitrification at 2100° F., and
viscosity at 2300° F.
At 2100° the clay burns to a good red, but above this temperature it
darkens rapidly.
The composition of this clay is as follows:
Analysis of Smoak's Brick-clay {No. 36), Wilkesboro.
Moisture 1.03
Silica (total) 53.75
Alumina 24.01
Ferric oxide 7.00
Lime 70
Magnesia 1.12
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 135
Alkalies . 2.94
Water (loss on ignition) 7.60
Total 100.04
Clay substance 54.04
Total fluxes 12.75
Free sand 46.00
Specific gravity 2.G3
The bottom clay (No. 37) at Smoak's brickyard is also a fine-grained,
yellowish-brown clay with abundant fine grit and small mica scales.
It slakes rather quickly and completely to its component grains. The
clay required 24$ of water to make a workable paste, which was some-
what lean.
This paste shrunk 6$ in drying and 9$ in burning, giving a total
shrinkage of 15$. The average tensile strength of the air-dried bri-
quettes was 71 lbs. per square inch with a maximum of 84 lbs.
Incipient fusion occurred at 1900° F., vitrification at 2100° F., and
viscosity at 2300° F.
The clay burns to a bright red at 1900° F., but this rapidly darkens
as the temperature is raised.
The physical characters of this clay are therefore closely similar to
that composing upper portions of the deposit.
The composition of this lower clay is as follows:
Analysis of Smoak's bottom Brick-clay (No. 37), Wilkesboro.
Moisture 2.10
Silica (total) 52.25
Alumina 20.66
Ferric oxide 11.14
Lime 60
Magnesia 1.08
Alkalies 4.62
Water (loss on ignition) 7.45
Total 99.90
Clay substance 57.45
Total fluxes 17.44
Free sand 42.45
Specific gravity 2.44
In fluxes this bottom clay runs several per cent, higher than the top
and contains less alumina.
This clay and the preceding one described underlie the same terrace
as does the pottery clay on the Calvin Cowles land, the two being not
more than half a mile apart (see p. 79).
136 CLAY DEPOSITS IN NORTH CAROLINA.
Mr. Smoak uses the yellowish clay for the manufacture of common
brick. It is molded by hand, dried in the sun and burned in up-draft,
permanent side-wall kilns. The clay makes a good brick, and also
yields promising results with re-pressing. Some of the re-pressed brick
are to be seen in the bank building at Xorth Wilkesboro.
CLAY IN WILSON COUNTY.
Near Wilson. — Sedimentary clay occurs in considerable quantity on
the east and northeastern edge of the town and is extensively worked.
The A. C. L. E. K. passes close to the deposits. At S. Lucas's yard,
northeast of the town along the railroad, the section is as f oIIoavs :
Sandy soil 1 ft.
Sand, clayey in spots 2 ft.
Sandy clay, red 3 ft.
Blue clay 3 ft. -f
The sandy soil is stripped and a mixture of the remaining portion of
the section used. Two openings have been made which show similar
sections, but the clay in the southern one is red while that in the north-
ern one is blue. Little iron concretions are not uncommon in the upper
portion of the bed, and these in burning produce fused spots.
The red clay (No. 4) is the more sandy of the two. It is a
gritty clay, porous and slakes very quickly. The addition of 32$ of
water gave a lean mass, which shrunk 10 fo in drying and 5$ in burning,
giving a total shrinkage of 15$. The average tensile strength of air-
dried briquettes made from this paste was SI lbs. per square inch and
the maximum 98 lbs. Incipient fusion occurred at 1800° F., vitrifica-
tion at 1950° F., and viscosity at 2100° F. The clay burns to a red
but not very dense body. With hard firing it becomes converted into a
black, impervious body in which the individual quartz grains stand
out with great distinctness.
The composition of the clay is as follows:
Analysis of red Brick-clay (No. 4), Lucas' Yard, N~. E. of Wilson.
Moisture 2.31
Silica (total) 62.99
Alumina 13.56
Ferric oxide 11.52
Ferrous oxide 0.33
Lime 10
Magnesia 29
Alkalies 2.07
Water (loss on ignition) 6.03
Total 99.20
BRICK-CLAY DEPOSITS IN NORTH CAROLINA. 13T
Clay substance 55.95
Total fluxes 14.31
Free sand 43.25
Specific gravity 2.62
The insoluble residue is probably mostly quartz, and the high per-
centage of ferric iron gives the clay its red color.
The blue clay is also gritty to the feel, somewhat finer grained than
the red, and slakes slowly to scaly grains in water. Like the red, it
shows no mica scales. It required 30$ of water to produce a workable
paste. This was quite plastic and shrunk 8$ in drying and 5.5$ in
burning, giving a total shrinkage of 13.5$. Briquettes of this air-dried
paste had an average tensile strength per square inch of 107 lbs. and.
a maximum of 129 lbs., much stronger, it will be seen, than the red.
Incipient fusion occurs at 1900° F., vitrification at 2050° F., and vis-
cosity at 2200° F. The clay burns to a red.
Its composition is as follows:
Analysis of Lucas' blue Brick-clay {No. 5), N. E. of Wilson.
Moisture 1.70
Silica (total) 68.90
Alumina 14.36
Ferric oxide 6.04
Lime 03
Magnesia 31
Alkalies 2.30
Water (loss on ignition) 5.83
Total 99.47
Clay substance 48.72
Total fluxes 8.68
Free sand 51.75
Specific gravity 2.45
Mr. Lucas has a second clay bank east of the town, from which he also
uses the clay for making common brick. The clay in appearance and
feel, chemical composition and physical properties, is closely like that
described above as used at the other yard, but the claim is made that it
not only shrinks less in burning but even swells sometimes. For this-
reason the clay was examined. The only apparent difference from that
at the other yard, northeast of the town, lies in its slightly higher fusi-
bility, and, consequently, with only the same amount of firing as that
given to the other clay, this one would shrink less. It is a gritty clay
which slakes slowly and requires the addition of 33$ of water to give a
workable paste that to the feel was very plastic. This paste shrunk
11$ in drying and 4$ in burning, giving a total shrinkage of 15$.
138 CLAY DEPOSITS IN NORTH CAROLINA.
The air-dried briquettes made from this paste had an average tensile
strength of 138 lbs. per square inch and a maximum of 155 lbs. per
square inch.
Incipient fusion occurred at 1950° F., vitrification at 2100° F., and
viscosity at 2250° F. The color of the burned clay was red. Its com-
position, as shown by the following analysis, corresponds closely with
that of the preceding sample.
Analysis of Lucas' Brick clay (No. 6), E of Wilson.
Moisture 1.68
Silica (total) 68.28
Alumina 13.59
Ferric oxide 5.66
Lime 15
Magnesia 47
Alkalies 2.82
Water (loss on ignition) 6.00
Total 98.65
Clay substance 43.69
Total fluxes . 7.69
Free sand 53.55
Specific gravity 2.52
Other clays of the same nature are exposed for some distance along
the railroad track north and south of Wilson. A number of buff brick
have been made from a deposit lying south of the town.
COMPARISON OF CLAYS FROM WILSON AND WAYNE COUNTIES.
The clays at Wilson and Goldsboro are, as has been previously stated,
of sedimentary nature and somewhat similar in character.
Experiments and actual practice point to the fact that very different
results can be obtained from these clays by the use of different methods.
Hand-molding, improper tempering and hurried burning give a poor,
porous, badly-colored brick. Steam power machines give a much
smoother brick. Auger machines were tried by some and given up in
disgust, but the machines used had the shortest possible pugmill and
the clay received no other tempering. When rolls are used they seldom
do more than flatten out the tough lumps of clay. In a cheap auger
machine the die is often improperly constructed, and laminations of the
worst kind may be produced in the brick. If the brick is not thor-
oughly burned, these laminations will result in the shelling off of frag-
ments from the brick.
CHAPTER X.
MANUFACTURE OF PAVING BRICK.
Few paving brick are manufactured in North Carolina, but as some
of the clays give indications of applicability for this purpose, it may
be well to say a few words regarding the manufacture of brick for pav-
ing purposes. General practice has shown that shales are par excel-
lence the material for making paving brick, for on account of their
fusible impurities they burn to such a dense body. Shales, however,
are not always obtainable, and then other clays have to be used. It
is highly probable that mixtures of clays can be used in North Carolina
for this purpose. ' A mixture of the top and bottom clay from Emma,
in Buncombe County, was tried and burned to a dense, hard body. The
clays at Elkin and Wilkesboro also burn to a dense, impervious mass,
but they lack somewhat in plasticity and would have to be mixed with
a more plastic clay.
REQUISITE CHARACTER OF CLAY.
Clays used for making paving brick should have sufficient fluxing
impurities to enable them to burn to a dense, impervious body at a
moderate temperature.
Wheeler1 gives the following average composition of a paving brick
clay deduced from fifty reliable sources.
Average composition of paving-brick clay.
Minimum Maximum
percent. percent. Average.
Moisture 0.5 3.0 1.5
Silica 49.0 75.0 56.0
Alumina 11.0 25.0 22.5
Ferric oxide 2.0 9.0 0.7
Lime 0.2 3.5 1.2
Magnesia 0.1 3.0 1.4
Alkalies 1.0 5.5 3.7
Water (loss on ignition) 3.0 13.0 7.0
Total mixes 13.0
Chemical composition alone does not determine the use of a clay for
paving brick. It should be quite plastic to permit molding without
1 Vitrified Paving Brick.
140 CLAY DEPOSITS IN NORTH CAROLINA.
tearing in a stiff-mud auger machine, but not excessively plastic, other-
wise laminations result.
From a commercial standpoint, it is of course desirable that the
shrinkage in drying and burning should be moderate, and that the clay
will permit drying in 24 to 36 hours. In fact, the lengthening of any
of the stages of the process of manufacture increases the cost.
An important point is that the greater the difference in temperature
between incipient fusion and viscosity the safer it is to thoroughly
vitrify the brick. The difference in temperature between incipient
fusion and viscosity should not be less than 250° F. and preferably
400° F.1
The color of a paving brick is no indication of its quality.
MANUFACTURE OF PAVING BRICK.
If shale is used it is first crushed in a dry pan and then screened.
The screened clay is mixed with water in a pugmill of the type de-
scribed under building brick.
From the pugmill the clay passes into the stiff -mud machine, which
has been already mentioned (p. 97). Few paving brick manufacturers
now use anything except the auger machine. The brick may be either
end-cut or side-cut according to the clay. Re-pressing the green brick
is also commonly done, but the manner of re-pressing may have a
marked effect on the wearing power of the brick.
Experiments by Prof. E. Orton, Jr.,2 have shown that end-cut
re-pressed paving brick are the toughest.
The brick are generally piled on cars and run into tunnels to dry.
These tunnels are heated by steam-pipes, or coal or oil fires.
The cars are run in at one end and always discharged from the
other.
Paving brick should be burned in down-draft kilns, as they give far
better results than the up-draft ones. The kiln may be either circular
or rectangular. Circular kilns have small capacity and are cheap to
erect, but little used outside of Ohio. Their capacity is about 25,000
brick.
Rectangular kilns of 150,000 to 200,000 capacity are the most used.
There are several types, but their principle is the same. The flames
and heat enter the kiln at the bottom and pass upwards in jDOckets set
against the wall of the kiln and running half-way or three-quarters to
the roof. The heat escapes from the top of the pockets or bags into
the kiln, passes downward through the brick and out through the open-
ings in the floor to the flues leading to the chimney.
1 Olchewsky. in Post. Chem. Tech. Analyse, 1890, and Wheeler, Vitrified Paving Brick, 1895.
2 Clay Worker, Feb. and March, 1897.
MANUFACTURE OF PAVING BRICK. 141
The difference between the various makes of kiln consists in the size
and shape of the fireplaces, arrangement of flues, slight differences in
bag walls, number of stacks, etc. Among the various types may be
mentioned those of Eudaly, Graves, etc. Figure 2 of Plate X (p. 101)
shows a Eudaly down-draft kiln.
As paving brick soften somewhat in burning to vitrification, it is nec-
essary not to make too many courses, otherwise the lower ones are liable
to be crushed out of shape. The water-smoking period varies accord-
ing to the clay, but 3-4 days is the average, and the burning takes from
4 to 7 days longer. The kiln should be cooled very slowly in order to
anneal the brick and give it that great degree of toughness character-
istic of all good pavers.
Great care should be taken to avoid any cold air entering the kiln
and checking the pavers.
At several localities continuous kilns are used in the burning of pav-
ing brick, but while they work fairly well, they are not yet a thoroughly
established success.
142
CLAY DEPOSITS IN NORTH CAROLINA.
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I
BIBLIOGEAPHY.
Such a list could be made to include thousands of titles, but all that
is intended here is to give the titles to the more important and easily
obtained works on clays and the manufacture of clay products.
The German works contain much that is of importance on the tech-
nology of clay-working, and many of them can be obtained at reason-
able rates.
For an exhaustive index the reader is referred to the Bulletin of the
U. S. Geological Survey, by J. C. Branner, given below.
The articles which are mainly locality reports are marked a; those
dealing largely with the technology alone, b; reports treating of both
are marked c.
Barber, E. A. Pottery and Porcelain of the United States. Xew
York, 1893. (Historic.)
Bischof, C. Die Feuerfesten Thone. Leipzig, 1895 (b).
Blue, A. Vitrified Bricks for Pavements, 3d Ann. Kept. Ontario
Bureau of Mines, p. 103. Toronto, 1893 (b).
Blatchley, AY. S. Clays of Coal-bearing Counties of Indiana, Ind.
Geol. Surv., 20th Ann. Kept., p. 24, 1896 (c).
Bock, O. Die Ziegelei-Industrie. Leipzig.
Branner, J. C. Bibliography of Clays and the Ceramic Arts, Bull.
IT. S. Geol. Surv. No. 143, 1896.
Chamberlin, T. C. Geol. of Wisconsin, vol. II, p. 235, 1877, and I,
p. 668, 1883. Describes Milwaukee brick and clay (a).
Cook, G. H. Clays of Xew Jersey, Geol. Surv. X. J., 1878 (a).
Cook, R. A. Manufacture of Fire-brick at Mt. Savage, Md., Trans.
Amer. Inst. Min. Eng., vol. XIY, p. 698, 1886 (b).
Cox, E. T. Porcelain, Tile and Potters' Clays, Ind. Geol. Surv.,
1878, p. 154 (a).
Davis, C. T. Bricks, Tiles and Terra Cotta. Philadelphia,
1884, second edition 1889 (b).
Dummler, K. Ziegel und Thonwaaren Industrie in den Yereinigten
Staaten. Halle, 1894 (b).
Griffiths, H. H. Clay Glazes and Enamels. Indianapolis, 1S95 (b).
Hill, R. T. Clays of the United States, U. S. Geol. Survey, Mineral
Resources, 1891, p. 474 (a).
Hofman and Demond. Tests on the Refractory Character of Fire-
clays, Trans. Amer. Inst. Min. Eng., vol. XXIY, p. 42, 1895 (b).
_
BIBLIOGRAPHY. 151
Holmes, J. A. The Kaolin and Clay Deposits of North Carolina,
Trans. Am. Inst, Min. Eng. XXV, p. 929, 1896 (a).
Irelan, L. Pottery, 9th Ann. Eept. Cal. State Mineralogist,
p. 240, 1890 (5).
Johnson, W. I). Clays of California, 9th Ann. Report. Cal. State
Mineralogist, p. 287, 1890 (a).
Kerr, W. C. Geology of North Carolina, vol. I, 1875, pp. 29G, 297.
Ladcl, G. Clays of St. Louis County, Mo., Bull. Mo. Geol. Surv.
No. 3, 1890 (a).
Langenbeck, K. Chemistry of Pottery. Easton, 189 G (b).
Lesley, J. P. Kaolin Deposits of Delaware and Chester Counties,
Pa., Ann. Kept. Pa. Geol. Survey, p. 571, 1885 (c).
Loughridge, K. H. Clays of Jackson Purchase Kegion, Kentucky,
Kentucky Geol. Surv., p. 77, 1888 (a).
Meade, D. W. Manufacture of Paving Brick, Trans. Amer. Soc.
Civ. Eng., vol. XXIY, p. 553, 1893 (&).
Orton, Edward, Jr. Clays and Clay-working Industries of Ohio,
Ohio Geol. Survey, vol. VII,^part I, p. 69, 1893 (b).
Periodicals :
Brick (monthly), Chicago, 111.
Brickbuilder (monthly), Boston, Mass.
Brickmaker (bi-weekly), Chicago, 111.
Clay (quarterly), Willoughby, O.
Crockery and Glassware Journal (weekly), N. Y.
Clay-worker (monthly), Indianapolis, Ind.
Paving and Municipal Engineering, Indianapolis, Ind.
| Thoninclustrie Zeitung, Berlin, Germany.
Topfer- und Ziegler-Zeitung, Berlin, Germany.
Phillips, Wm. B. Eng. Min. Jour., XLII, p. 326; and Jour. Iron
and Steel Industry, 1887, No. 1, p. 389 (c).
Piatt, F. Test of Fire-Brick, Pa. Geol. Survey, Kept. M. M., p. 270,
1879 (b).
Pies, LI. Clays of United States, Mineral Industrv, 1891, vol.
II (c).
Pies, H. Clays of Hudson Kiver Valley, 10th Ann. Kept, of N. Y.
State Geologist, 1890 (c).
Pies, IL. Clay Industries of New York, Bull. N. Y. State Museum,
vol. Ill, No. 12," 1895 (c).
Pies, H. Technology of Clay-working Industry and Analyses of
Clays of U. S., IT. S. Geol. Surv., 16th Ann. Kept., pt. IV, p. 523 (6).
Pies, H. Pottery Industry of United States, 17th Ann. Kept. U. S.
Geol. Survey, pt. Ill, p. 842 (&).
\
152 CLAY DEPOSITS IN NORTH CAROLINA.
Hies, H. The Clays of Florida, 17th Ann. Kept. U. S. Geol. Sur-
vey, pt. Ill, p. 871 (a).
Ries, H. Clays of Alabama, Bull. Ala. Geol. Survey, 1897 (a).
Ries, H. The Clay-working Industry in 1896, 18th Ann. Rept.
U. S. Geol. Survey, pt, Y, p. 1105, 1897 (c).
Ries, H. The Ultimate and Rational analysis of Clays and their rela-
tive advantages, Trans. Amer. Inst. Min. Eng., XXVIL
Smith, E. A. Clays of Alabama, Ala. Indus, and Sci. Soc, vol. II,
1892 (a).
Smock, J. C. Mining Clays in New Jersey, Trans. Amer. Inst.
Min. Eng., Ill, p. 211, 1874-75 (&).
Smock, J. C. Xew Jersey Clays, ibid., vol. YI, p. 177, 1879 (a).
Spencer, J. W. Clays of Georgia, Ga. Geol. Surv., p. 276, 1893 (a).
Struthers, J. Le Chatelier Thermo-electric Pyrometer, School of
Mines Quarterly, vol. XII, p, 143, and vol. XIII, p. 221 (b).
Wheeler, H. A. Fusibility of Clays, Eng. and Min. Jour., XYII,
p. 224, 1894.
Wheeler, H. A. Yitrifled Paving Brick. Indianapolis, 1895.
Wheeler, H. A. Clays of Missouri, Mo. Geol. Survey, vol. XI, 1896.
Young, Jennie J. Ceramic Art. Xew York, 1878 (b).
Zwick, F. Die Ziegel Industrie. Leipzig, 1894.
NDEX.
PAGE
Absorption of water by clays 42
Air-drying of clays 26
Alabama clays, silica in 24
Aleksieje w cited 34
Alkalies in clay 16, 17,
advantage of
coloring influence of , in . . 18
determination of, in clay 27
fixed in clay
soluble alkaline compounds
sulphates as fluxes
insoluble " "" "
silicates as fluxes —
Aluminium oxide in clay, determination of. .28
Ammonia in clay 16
Analyses of clays (see brick-clay, fire-clay,
pottery-clay, pipe-clay and kaolin),
142,149
methods of making 27
rational analyses 9, 29, 30
Asbury's brickyard 125
Auger machine 97
Asheville, brick clay near — 104
Baskerville, Chas., analyses by ... 9, 27
quoted 27
Bibliography 150
Biltmore, brick-clay near 106
Bikchof, C, quoted 24,35
Blackburn, pottery industry at . . 76
Bostick, kaolin near . 65
Brick-clay deposits in North Carolina. . .92, 102
Brick for building 93
effect of calcium carbonate on 21
manufacture, methods of 94
soft-mud process — ....94
stiff- " " 96
dry-press " • 99
Brick-clays and brick manufacture 92
Brick-clays, general characters of 92
effect of sand on 93
requisites of 93
analyses of 103,104,
105, 107, 108, 109, 110, 111, 112, 113,
114, 115, 116, 117, 118, 119, 120, 121,
122, 123, 124, 125, 126, 127, 128, 129,
130, 132, 133, 134, 135, 136, 137, 138.
preparation of 94, 96, 100
tempering 94, 96
molding 95, 97, 101
burning 95, 98, 101
Brick-clay, deposits in North Carolina 102
in Bladen county 102
near Prospect Hall 102
PAGE
Brick-clay, in Bladen County, on property
of Wm. Whitted 102
in Buncombe county — 104
Penniman's clay bank, near
Emma 104
near Asheville and Biltmore. 1C6
near Fletcher 106
Buncombe Brick Co 106
in Burke Co 107
near Morganton 107
in Cleveland Co 108
near Grover 108
in Cumberland Co 110
near Fayetteville — 110
in Forsyth Co HI
near Bethania Ill
Carter & Shepherd's clay b'k.113
in Gaston Co 113
near Mt. Holly 113
in Guilford Co 114
near Greensboro 114
Dean's brickyard 115
Kirkpatrick's brickyard 115
Watson's brickyard 115
in Halifax Co 116
near Roanoke Rapids 116
" Weldon 119
" Halifax 119
in Harnett Co ... ... 119
near Spout Springs 119
in Jackson Co 121
near Sylva 121
in Martin Co 122
near Williamston 122
in Mecklenburg Co 122
near Charlotte 122
Cecil's yard 123
Houser's yard 123
Sassamon's yard 123
Shuman's deposit 124
Asbury's brickyard 125
in Richmond Co . • 125
near Rockingham 125
in Robeson Co 12&
near Red Springs . . 126
in Rowan Co 127
near Salisbury 127
in Surry Co 128
" near Elkin 128
in Union Co 129
near Monroe 129
Shute's clay-bank 129
in Wake Co 130
154
INDEX.
Brick-clay, in Wake Co., near Raleigh 130
in Wake Co., Penitentiary brick
yard 130,131
Green's property 131
Caraleigh Mills Co 131
in Wayne Co 131
near Goldsboro 131
Goldsboro Brick and Tile Co.131
Weil & Bros, yard 133
in Wilkes Co 134
Smoak's yard 134
in Wilson Co 136
near Wilson 136
Lucas property 137
BrindeFs kaolin deposit 62
Buncombe Brick Co 106
Burke Co., pottery industry in 75
brick-clays in 107
Burning brick 94,95,96,98,101
updraf t kilns 98
continuous kilns 98
Calcium carbonate in clay 21
effect on brick 21
Calcium oxide in clay 28
Caraleigh Mills, brick-clay at 130
Carbonate of iron as source of iron in clays. . 19
Carbonic acid, action on feldspar 12
Carter and Shepard's clay bank 113
Catawba county, pottery industry in 76
Cecil's brickyard 123
Clay substance 14
Clay, absorption of water 42
absorbing lime 22
alkalies in 16
ammonia in 16
analyses of 142-149
bases in 11, 15, 16, 17, 18, 20, 21, 22, 23
brick (see brick-clay) 92
chemical analj'sis of 27
chemical properties of 15
china 50
character of for paving-brick 139
color of, unburned 20
color of 43
composition of (see analyses) 11
compounds of iron in 18,19,20
comparison of, from Wilson and
Wayne counties , 138
Cretaceous and Tertiary 12
defined 11
density of 43
effect of calcium carbonate in, on
brick 21
Forsyth county Ill
near Fayetteville 110
fire-shrinkage of 35
fire-clay (see fire-clays, p. 155).
fluxing impurities in 15-23
fusibility of 36
geology and geography of, in N. C 44
hornblende in 12
impurities in 15
lime in 15,20
magnesia in 15, 23
Clay, non-fluxing impurities in 23
origin of n
organic matter in 25
pipe-clay in North Carolina , 86
plasticity of 25. 26. 33. 34
preparation of 54,94,96,100
properties of 11, 14
pure, composition of 11, 14
purity of, depends on 12
physical properties of 33, 42
pottery clays in N. C 71
pottery clay, requisites of 72
removing lime from 21
residual clays (see residual) .... 12, 44, 92
substance 14
sedimentary 12, 13, 46, 92
shrinkage of 35
silica in 24
silica, two classes of , in 24
silica, free, in 24
silica in Alabama clays 24
" " North Carolina 24
slaking of 42
sulphuric acid in 15
taste of 43
tempering the 94, 96
temperature at which clay fuses 37
tensile strength of 34,35
texture of 42
titanium in 24
variation in composition of 13, 14
water in 26
working industries 48
Clay, brick, near Asheville 106
Bethania .111
Biltmore 106
Charlotte 122
Elkin 128
Fayetteville 110
Fletcher 106
Goldsboro 131
Greensboro 114
Grover 108
Halifax 119
Monroe ..129
Morgan ton 107
Mount Holly 113
Prospect Hall 102
Raleigh 130
Red Springs 126
Rockingham 125
Roanoke Rapids 116
Salisbury 127
Spout Springs — 119
Sylva 121
Weldon 119
Williamston 122
Wilson 136
Wilkesboro 134
Clays from Wilson and Wayne counties
compared 138
Clay deposits, geology and geography of
North Carolina. 44
Cleveland cou nty , fire-clays in 81
INDEX.
155
Cleveland county, brick-clays in 108
Cook, Prof. G. H., quoted 33
Continuous kilns . ...98
Coal mixed with clay in burning brick 96
Color of clays 43
Compounds of iron in clay 18
Combined water in clay 26
Cramer cited 25
Cremiatschenski cited 34
Deans' brickyard 115
Density of clays 43
Deposits of kaolin in North Carolina 58
Dry-press process 99
preparation of clay for 100
molding- in 101
burning the brick in 101
Determination of moisture in clay 27
water " "" 27
alkalies " " 27
silica " " 27,28
iron sesquioxide 28
aluminium oxide 28
calcium " 28
magnesium " 28
insoluble residue 28
titanic oxide — 29
sulphur 29
ferrous oxide 29
rational analyses 29
Distribution of the kaolins 50
Elkin, brick-clay near 128
Emma, Penniraan's clay bank near 104
Fayetteville, brick-clay near 110
Feldspar, orthoclase 11, 17, 18
action when fused 16
alkalies in 16,17,18
weathering of 12
Ferric oxide in clay . ..19
percentage desirable 20
Ferric silicate in clay, effect of 19
Fire-brick, manufactured 48
Fire-clays 80
characteristics of 80
analyses of 81, 82, 83, 84, 85
in Cleveland Co 81
near Grover 81
in Guilford Co 83
Pomona clay-bank 83
Woodroffe clay-bank 85
Fletcher, brick-clay near 106
Fluxes, in clay, per cent. of,16, 17, 18, 19, 20, 21, 22
Fluxing impurities in clay 15-23
Forsyth county, brick-clays in Ill
Fusion of clay, incipient 36
stages of 36
temperature of 37
Fusion temperatures, table showing 39-41
Fusibility of clay 36
Gaston county, brick-clay in 113
Geology and geography of North Carolina
clays 44
Goldsboro, brick-clays near 131
Goldsboro Brick and Tile Co 131
Greensboro, brick-clay near 114
Greensboro Brick and Tile Co.'s yard 114
Green's property 131
Grover Brick Company 81
Grover, brick-clays near 108
Gypsum in clays 22
Guilford county, fire- clays in 83
Pomona clay-bank 83
Woodroffe clay-bank — 85
pipe-clays in 88
Pomona Terra Cotta Co.'s
works 88
brick-clay in 114
Halifax county, clay in 116
brick-clays near 119
Harris Clay Co 59
Harnett county, brick-clays in 119
Hematite, an impurity in clay 18, 19
Houser's brickyard 123
Holmes, J. A., cited 46
Hornblende in clays 23
Hygroscopic water in clay 26
Ignition, loss on, in clay 27
Industry, clay working in North Carolina. . .48
pottery, The 71
Impurities in clay . .15, 16, 17, 18, 19, 20, 21, 22, 23,
24,25
fluxing impurities 16
non-fluxing impurities 23
in residual clay 12
Infusibility of kaolinite 15
Insoluble residue, determination of 28
Iron compounds in clay 18, 19, 20
Iron sesquioxide, determination of 28
Iron, a coloring agent 19, 20
percentage permissible in clay 20
in N. C. kaolins 20
sources of, in clay 18
Incipient fusion of clay — 36
Jackson county 58
brick-clay in — 121
kaolin in 58, 59, 60, 61, 62
Jolly-wheel — 74
Kaolin, analyses of 59, 61, 62, 63, 65, 67, 68, 69
Kaolin, Bostick's Mills 65
china clay 50
comparisons of North Carolina with
foreign ones 69
composition of 52
distribution of 50
fluxes in 16
Harris Clay Co.'s mine 59
iron in 53
Jackson county 58
mineralogical character of 50
mining of 53
Montgomery county 64
North Carolina Mining and Mfg. Co.'s
mine 58
preparation of 54
plasticity of, inci-ease by grinding.. 15
properties of 51
Richmond county 65
Springer's pit 61
Steele's deposit 65
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156
INDEX.
Kaolin, Sylva 58
Troy 64
uses of, North Carolina 68
Wests Mill 62
Webster 59
Kaolinite, composition of 11, 12
described 15
formation of 11
origin of 11
refractoriness of 15
Kilns 98
up-draf t 98
continuous 98
Kirkpatrick's brickyard 115
Langenbeck cited 59
Lime, compounds of, in clays 20, 21, 22
absorption of into clays 22
as carbonate, effect on clay 21
as silicate, ik " " 21
as sulphate, " " " 21,22
effect on brick 21
in North Carolina clays 23
Limonite, a frequent impurity in clays. .18, 19
Lincoln county, pottery industry in 77
Lincolnton , pottery industry near 77
Lithia in clays 16
Lucas, brickyards of 137
Macon county, kaolin in 62
Magnesia, origin of, in clay 23
in clays. 23
in North Carolina clays 23
Magnesium carbonate 23
oxide in clay, determination of .28
sulphate 23
Manufacture of brick 92
of stoneware 73
of sewer-pipe and tiles 86
of paving-brick 139, 140
Martin county, brick-clay in 122
McDowell, Manly, pottery clay 75
Measurement of temperature 38
Mecklenburg county, brick-clay in 122
Methods employed in making clay analyses. 27
Methods of brick manufacture 94
soft-mud process 94
stiff-mud process 96
semi-dry press 94, 101
dry-press 99
Mineral impurities in clay 15
Mining of kaolin 53
Moisture in clays — . 26
hygroscopic 26
chemically combined 26
determination of 27
Molding brick . 94, 95, 97, 101
Monroe, brick- clays near 129
Montgomery county, kaolin in 64
Morganton, pottery industry near 75
brick-clays near 107
Mount Holly, brick-clays near ] 13
Non-fluxing impurities in clay 23
North Carolina clay-working industry, The. 48
deposits of kaolin in 58
pottery clays in 71
North Carolina fire-clays and pipe-clays in. .80
pipe-clays in 86
brick-clay deposits in 102
clays, silica in 24
Olschewsky quoted 34, 140
Organic matter in clays 25
effect of, on clay 25
Origin of clays u
Orton, E., Jr., cited 84, 140
Oxides in clay 15, 18
Oxygen, a weathering agent 12
Paving brick, manufacture of .... 139,140,141
analysis of clay for 139
character of clay requisite for
139
kilns for 140. 141
Penitentiary yard, Raleigh, brick-clay at .130
Penniman, clay bank, near Emma 104
Percentage of iron admissible in clay 20
in N. C. kaolins 20
Physical properties of clay 33, 42
Pipe-clays in North Carolina 86
analyses of 89,90
methods of manufacture. .86, 87, 88
in Guilford county 88
Pomona Terra Cotta Co's works. 88
requirements of 86
tensile strength of 86
Plasticity in clays 34
in kaolinite increased by grind-
ing 15
effect of organic matter on 25
Poe & Bros, yard 110
Pomona Terra Cotta Co 83, 88
Sewer-pipe and Brick Co 86
Potash in clay 11, 15, 16, 18
Pottery clays in North Carolina 71
Pottery clay, requisites of 72
analyses of 75. 76, 77, 78, 79
Burke county 75
Blackburn 76
Catawba county 76
Cowles, Calvin 79
Lincoln county 77
near Lincolnton 77
Rhodes, T 77
Wilkes county 78
Wilkesboro 78
Pottery industry, The 71
in Burke county 75
at Blackburn .' — 76
in Catawba county .76
in Lincoln county 77
near Lincolnton ... 77
near Morganton 75
in Wilkes county 78
in Wilkesboro 78
Powhatan Clay Mfg. Co 81, 82
Preparation of clay for bricks 94, 96, 100
fire-clay 80, 81
kaolin 54, 55, 56, 57, 58
pipe-clay 86
pottery-clay 72
clay for paving-bricks 140
timh Carolina Sfate library
Raleigh
INDEX.
157
Pressed brick
Properties of kaolin
Prospect Hall clays
Pyramids, Seger's ...
Pyrite in clay ..
Pyrometers
49
51
.102,103,104
38
18,19
38
Thermo-electric, The 38
Seger's pyramids 38
Purity of clay depends on 12
Raleigh, brick clays near 130
Rational analysis of clay, The 30
method of making 29
practical bearing of 31
Refractoriness of clay 37
Requisites of a brick-clay 93
fire-clay . . 80
pipe-clay 86
Red Springs, brick-clay, near 126
Residual clays 12,44,92
composition of 45
impu rities in 12
Residue, insoluble, determination of .. 28
Rhodes property, pottery clay 77
Richmond county, kaolin in 65
brick-clay in 125
Roanoke Rapids, brick-clay near 116
Rockingham, brick-clay near .125
kaolin near 65
Roberdell, brick-clay at 125
Robeson county, brick-clay in 126
Rowan county, brick-clay in 127
Salisbury, brick-clay near 127
Sand, effect of, on brick-clays 93
Sassamon's brickyard 123
Sedimentary clays 46, 92
Seger, quoted 20, 22. 52
Seger's pyramids 38
•> fusion temp, ratures of 39, 40, 41
Semi-dry-press process 94, 101
Sewer-pipe 86
method of manufacture. .. 86,87,
88,91
Pomona Terra Cotta Co 88
Shales, used as clays 12,13
metamorphism of 13
Shrinkage of clays 35, 36
Shute's clay-bank 129, 130
Shuman's deposit 124
Silica, determination of in clays 27
in clays 24
effects of on clays 24
Silicates, in clay 11
of iron in clay 18, 19
Slaking of clays 42
Smoak'syard 134
Soda in clay 15,16,17
Soft-mud process 94
tempering the clay 94
molding the brick 95
Soft-mud burning 95
Spout Springs, brick-clay near 119
Springer clay-pit 61
Stiff-mud process 96
tempering the clay 96
molding 97
burning 98
Stoneware manufacture 73, 74, 75
Sulphur in clay, determination of 29
Sulphates as a source of iron in clays .... 18, 19
Sulphides " " " " " " " ... 18,19
Sulphuric acid in clays 15
Surry county, brick-clay in 128
Sylva, brick-clay near . 121
Table of variations in clay substance 52
Taste of clays 43
Temperature at which clay fuses 37
measurement of 38
Tempering clay, soft-mud process 94
stiff-mud " 96
Tensile strength of clays 34
Terra-cotta ware 88
Company, Pomona 88
Texture of clays 42
Thermo-electric pyrometer, The 38
Tiles, manufacture of 86
Titanium in clay 24
as a flu x 25
Titanic oxide, determination of 29
Union county, brick-clay in 129
Uses of North Carolina kaolin 68
Variations in clay 13,14
Variation in clay substance, etc., table
showing 52
Viscosity of clay 36
Vitrification of clay 36
Wake county, brick-clays in 130
Water in clays 26
absorption of, by clays 42
hygroscopic 26
combined 26
Watson's brickyard ... 115
Wayne county, brick-clays in 131
Weathering of feldspar .12
Webster, kaolin near 59
Weil & Bros, brickyard 133
Weldon, brick-clays near 119
Wests Mill, kaolin near 62
WT heeler cited 34,37,139
Whitted, Wrilliam, clay on land of 102
Wilson county clays 136
brick-clays in 136
Wilson, brick-clays near 136
Wilkes county " " in 134
pottery industry in 78
Wilkesboro, pottery industry near 78
brick-clays near ..134
Williamston 122
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STATE LIBRARY OF NORTH CAROLINA
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