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Diq.izeobvl^OOQle
WORKS OF
Dr. GEORGE P. HERRILI,
JOHN WILEY & SONS.
Thicd Bdilion, RcTiHd uid EnlircHl. m, i-(-5g
piC»> one dauble-pa(e and )■ [uD-paga platen uid
•4 Hgaru Id teit. C\alb, Ij.od.
Tb« Non- metallic MIhtbIi.
Tbtlr Occumacs tuid Ums. Second Bdidoa
RnHwd and Enlusad, Svo, di + 431 pi
j8 fnltpagB pintea, moitly half-tfnxca, uu
Bmm [a tbo Mxt Cloth, tt.ae.
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PLATE I.
Views in Graphite Mine neat Hague, Warren Couniy, New ^°''K OOqIc
[From photograph by C. D. Walcoll,] ^ O
[Fronlispiecc.]
r'S
THE
NON-METALLIC MINERALS.
THEIR OCCURRENCE AND USES.
GEORGE P^MERRILL,
Htad Cttrater of Geology in tin U. S. NaUonat Miuatm, and
FrtftSMr e/ Gtology in tht George Washvigton (Jontterly Coimriiian) Uwitrnty,
Wiuhaigfon, D. C; Author of " Stones for BiHl4ing and DecoratioH,"
"Seelu, Sock-titathtring, and Soili," " CotitribiUioni to a
History <^ Asiuricoit Ctology," etc.
SECOND EDITION, REVISED
FIKST THOUSAND
NEW VORK :
JOHN WILEY & SONS.
London: CHAPMAN & HALL, Liumn.
19 lO
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Vi\5 3i.y\^ ^>h.:^..LM--
Coprriillt, T904, 19IO,
GEORGE P. MERRILL
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PREFACE TO THE SECOND EDITION.
The first editkm of this work was little more than a reprint
of a handbook of the collections in Applied Geology in the
U. S. National Museum. An attempt was there made, for the first
time in America, to bring together widely scattered notes relating
to many of the minor and little used mineraJs, it being felt that with
the rapid development of the arts the time had come for a review,
at least, of this branch of the mining industry, as well as a look into
future possibilities, so far as the development of natural resources
would permit. Since the work was written, much has been accom-
plished in the way of both study and exploitation, as will be evident
to one who will peruse the voluminous publications of the U. S.
Geological Survey and the columns of the trade and mining journals,
and it is felt that the time has now arrived for putting the matter
in a form more concise as well as more comprehensive. la doing
this, the author has availed himself of the great mass of literature
passing through his hands as Head Curator of the Department of
Geology, as well as an experience of near thirty years in collecting,
observing and arranging the materials under his care. He has
drawn for information upon every available source, and has striven
to give full credit therefor.
The name Non-Metallic, as used, it may be well to state, relates
to the uses to which the various substances are put rather than to
their true mineral nature. Otherwbe expressed, the materials here
described are considered with reference to their uses other than as
sources of metals. In several instances, it is evident, the same mate-
rial may be utilized for its metallic constituents as well, as is the case
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with the mangaji'ese oxides, but In such cases this phase of the sub-
ject is touched upon but lightly.
It should scarcely be necessary to state that in several instances,
as those of cements, coals, phosphate, etc., the subject matter is so
comprehensive that each might well demand a. volume by itself.
In these cases, summaries only are attempted and reference made to
authentic treatises in the accompanying biblit^aphies.
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TABLE OF CONTENTS AND SCHEME OF
CLASSIFICATION.
L The Kements: ,„,
Diainond - i
Graphite 6
3. Sulphur 14
IL Sulphides and araenkles:
I. Realgar and orpiment ; auripigment aj
-^, Cobak mmereb 35
Cobahile 35
Smahhe a6
Skutterudite »7
Glaucodot 87
Unnjcite 37
Sychnodymile aS
Erythrile or cobftK bloom 38
Aabolite 38
3. AracDopyrile; mispickel or arsenical pyrites 30
4. Ldllingitei leucopyrite ji
5. Fyriies 3a
6. lytrhoiite 38
7. Molybdenite 39
8. Patronite; vanadium sulphide 41
m. Hftlides;
t. Halite; sodiiun chkuide; or comtnon.nlt 43
3. Fluorite 63
3. Cryolite 65
IV. Ondes;
1. Silira 67
Quartz ; . 67
FUut '. 68
Buhntone 68
Tripoli 69
Diatomaceous earth 70
a. Corundum and emery 73
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VI T^BLE OF CONTENTS AND SCHEME OF CLASSIFICATION.
IV. Oxides— Co nxiimal; ?«ob
3. Bauiite 89
4. Diaspore 103
5. Gibbsile; hydrargillite J03
6. Ocher; mineral pa[Ql 104
7. Ilmenite; meiucraniie, or liunic iron iii
8. Rutile 113
9. Chromite; chrome iron ore 114
10. Manganese oxides lal
Fiankliniie 133
Hausmannite iia
Brauoiie lat
Folianile 113
Pfro1u«te 113
Manganite 113
Psibmelane i»3
Wad or bog manganese 1*4
tl. Mineral waters 131
V. Carbonates:
I. Calcium carbonate 135
Cakile; ca.ic spar; Icebnd ^«r 135
Limestones 138
Portland cement 141
Roman cement 144
Chalk I4S
Playing marbles 14S
Lithographic limestones 147
9, Dolomite 151
3. MagncMte 153
4. Witherile 157
5. Stroniianite 158
6. Rhodochrosite; diallogile 159
7. Natron 159
8. Trona; urao 159
VI. Slliates:
I. Feldspars 161
3. Micas 164
3. Asbestos 183
4. Garnet 197
5. Zircon 199
t. Spixlumene and petalite 30a
7. Lazurite; lapis lazuli; native ultramarine 303
8. Allanlte; orthite 304
9. Gadoliniie 305
10. Cerite 307
11. Rhodonite 307
13. Steatite; talc and soapstone 30S
13. Pjirophyllite; agalmatolite and pinile ai6
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TABLE OF COlfTENrS AND SCHEME OF CLASSIFICATION. vii
IV. Silicates — Conlimttd; paoi
14. Sepjoliie; meencbduiii ai8
15. CInys 3JI
16. Fulier'a-tarth jjl
VIL NiolMles, Uniabtes, and tungstates:
t. Columbite and taataliEe J55
a. Yttrotantalite 355
3. SamarsVite 156
4. Wolframite, HUbnerile and Ferberite 257
5. Scheelite 263
VIII. Phaspbaus and vanadates:
I' Apatite; rock phosphates; guano, etc 166
a. Monasite 303
3. Torbemite 307
4, WaTcllile 308
S- Ambiygonite 309
6. Triphylite and lithiophilhe 310
7. Vanadinitc 311
8. Descioizite 313
XI. Nitrates:
I. Niter, potassium nitrate 315
». Soda nher 315
3. NilrOHAkile 31S
X. Borates:
I. Borax or lineal; borate of soda 313
1. Ulexite; boronatrocalcite 322
3. Colemanile; Priceite 321
4. BoiacltcOT stassfurtite; borate of magnesia 311
XI. Uia nates:
I. Uianiniie; pitchblende 330
a. Carnolite 333
XII. Sulphates :
1. Barile; heavy spar 334
2. Gypsum 337
3. Celeslile 343
4. Mirabilite; Glauber mtt 344
5. Olauberite 347
6. Thenardite 348
7. Epsomlte; epsom sahs 348
8. Polyhatite; kainite arul kieserile 349
9. Alums:
Kalinite 350
Tschermigite 350
Mendoaite ■ 351
Pickeringite 351
Halotrtchite 351
Apjonite 35 1
Alunnogen 35a
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viii TylBLE OF CONTENTS AND SCHEME OF CLASSIFICATION.
XII. Sulphates — Continutd: paoi
Alurainite 355
Alunite 3SS
Alum slate or shale 357
XIIL Hydrocarbon compounds:
1. Coal series 359 .
Peat 360
Lignile or brown coal 36a
Bilumionus coal 363
Torbanite 363
Anthracite coal 364
a. Bitumen series 3O7
Marsh gas; natural gas 37a
Petroleum 373
Asphaltum; mineml pitch 375
Manjak 38r
Elatertte; mineral caoutchouc .... 38a
Wurtallite 38a
Albertite , 383
Gr&hamite 384
Carbonjte or natural coke 3S5
Uintaite; gilsonite 386
3, Ozokerite; mineral nax; native' paraffin 388
4. Resins Sgr
Succinite; amber 391
Retinite 393
Chcmawinite 393
Gum copal 394
XIV. Miscellaneous:
I. Grindstones; whetstones and bones. 400
9. Millstones .--.. 409
3. Pumice 410
4. Rottenstone .-. ...... 4ri
5. Madsiones 413
6. Molding sand... 413
7. Sand for mortars and cements 418
8. Sand for glass making ....... 419
9. Glauconitic sand 4M
10. Rood-making materiats 43t
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LIST OF ILLUSTRATIONS.
I, Views in Graphite Mine, near Hague, Warwn Co., N. Y. From
photograph by C. D. Walcott Fiontiq>iece
II. Section of Sail Beds at Slassfurl, Germany. Trans. Edinbuigb Geo-
It^cal Society. Vol. V, 1884 56
III. Tripoli Mine, Seneca, Mo. From a photograph 70
IV. Bed of Diatom Earth, Great Bend of Pitt River, Shasta Co., Gal. From
photograph by J. S. Diller, U. S. Geol. Survey 7a
V. Vein beiweeo Peridotite and Gneiss, Corundum Hill, Macon Co., N. C.
After ]. H, Pratt, Bull. No. 180, U. S. Geol. Survey 76
VI. Fig. 1, Corundum Vein at Laurel Creek, Ga. After J. H. Pratt, Bull.
No. 180, U.S. Geol. Survey 78
Fig, a, Bauxite Bed, Saline Co., Ark. From photograph by C. W. iJayea,
V. S, Geol. Survey 78
VI!. Microstructure of Emery. After Tscbermak, Min. u. Pet. Mittheil.,
XIV, Part IV 8a
VIII. Church Bauxite Bank, showing Method of Mining. From a phologiaph
by C. W. Ilayea, U. S. Geol. Survey 94
IX. Fig. I, Segiegaiion Veins of Chrome Iron, near Ruslenburg, South Africa.
From Trans. Geol. Soc. of South Africa 116
Fig. 3, Open Cut Manganese Mine, Crimora, Virginia. After Thos. Wat-
son, Mineral Resources of Virginia I16
X. Botryoidal Psilomelane, Crimora, Viiginia 114
XI, Ideal Sections to Show Origin of Manganese through Weathering of
Limestone. After Penrose, Ann. Rep. Geol. Survey of Arkansas,
Vol. I, 1890 it6
XII. Views Showing Occurrence of Calcite in Iceland. After Thorroddsen. . . ijC
XIII. Fig. I, Limestone Quarry, Rockland, Me. From pbotograph by E. S.
Bastin, U. S. Geol. Survey 138
Fig. a. Limestone Quarry, Oglesby, III. From a photograph by E. C.
Eckel, U. S. Geol. Survey 138
XIV. Cement Quarry, near Whitehall, Ulster Co., N. Y. From photograph
by N. H. Darton, U. S. Geol. Survey 144
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X UST OF ILLUSTRATIONS.
XV. Fig. 1, Quairy of Lithographic Limestone, Solcnhofcn, Bavaria.
From a photograph 154
Fig. ], Stockivork of Magnesite Vrina in Serpentine, near Winchester,
Riverside Co., Cal. After F. L. Hess, Bull. No. 333. U. S.
Geol. Survey. 154
XVI. Fig. 1, Magnesitc Outcrop, Hiion Ranch, Mendocino Co., Cat. Ihid. 156
Fig. i, Sonoma Magnesitc Mine, near Cauidero, Cal. Ibid. 156
XVn. Fig. I, Feldspar Quarry, Topsharo, Me, From photograph by E.
S. Bastin, U. S. Geol. Survey its
Fig. 2, Feldspar Quarry, South Glastonbury, Conn. Ibid- 161
XVIIL Fig. I, Large Spodumene CrysUls in Granitic Rock, Etta Mine,
Black Hills, S. D. From photograph by E. O. Hovey aoo
Fig. 1, Soapstone Quarry, Nelson Co., Va. After Thos. Watson,
Mineral Resources of Virginia. 100
XIX. Soapstone Quarry, Lafayette, I'ennsylvania 314
XX. Kaolin P.t, Delaware Co., Pennsylvania 320
XXI. Fig. 1, Kaolinite, and Fig. 3, Washed Kaolin as Seen under the
Microscope ■■ 22%
XXII, Fig. I, Halloysile, and Fig. 1, Glacial (Leda) Clay, as Seen under the
M icroscope. 830
XXIII. Bed of Glacial (Leda) Clay, Lewiston, Me., from photograph hy L. H.
Merrill 232
XXIV. Fig. I, Fuller's Earth Pits, Quincy, Fla. After H. Ries, Clays, Their
Properties and Uses; Fig. 2, Phosphate Pit, Florida 351
XXV. Fig. 1, Clay, Albany. Wyo., and Fig. i, Fullers' Earth, as Seen under
the Microscope aS4
XXVI. Map of the Ftorida Phosphate Regions, after G. H. Eldridge, U. S.
Geol. Survey 278
XXVII. Sections through the Tennessee Fho^hate Beds. After C. W. Hayes,
U. S. Geol. Sun-ey 382
XXVIII. Phosphate Mine, Mt. Pleasant, Tenn, Showing Area Stripped, and
Method of Mining. From photograph by C. W. Hayes, IJ. S.
Geol. Survey 184
XXIX. Monazite Mining, Gallney, S. C. From photograph by Douglas
Slerrelt, U. S. Geol. Survey 304
XXX. Borax Mine, near Daggett, Cal. Interior and Exterior Views. From
photographs 316
XXXI. Gypsum Quarry, Fort Dodge, Iowa. From photograph by Iowa
Geol. Survey 338
XXXII. Map Showing Developed Coal Fields in the United Stales. From
Rep. of Eleventh Census 360
XXXIII. Fig. I, Typical Moss or Peat Bog, near Augusta, Me. After E. S.
Bastin. Bull. 376. U. S. Geol. Survey; Fi^. 2, Scciion ota Peal
Biig, near Mias, Russia. From a photograph by A. M. MiUcr.. 361
XXXIV. Fig. 1, Quarry in Bituminous Sandstone, Oklahoma. After G. II.
Eldridge, U. S. Geol. Survey; Fig. a, Ditto, Santa Cruz District,
California 364
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LIST OF ILLUSTRATIONS.
XXXV. Microstructure of Mies Schist Used in Making Hones; Fig. i cut
across the grain; Fig. i, cut parallel with grain 404
XXXVI. Fig. I, Quarry in Mica Schiat used in malting Whetstones, Pike
Manuracturing Cii.; Fig. a. Quarry in Novacull.e, Arkansas,
Pike Manufaclurina Ct 406
XXXVII. Microstructure of (i) Arkansas Novaculile, and (3) Batisbon Raior
Hone. The dark bodies in (3) are Garnets 408
XXXVIII. Fig. I, Bed of Pumice Dust, Kansas. From a photograph; Fig. a.
Quarry of Quartt Sand, Ottawa, lit. From a photograph 41a
FIGURES IN TEXT
I. Diamond Crystals. Ann. Rep. U. S, National Museum, 1903 a
3. Section of Kimberley Mines, S. Africa. After Rennert 3
3. Largest Known Black Diamond. After Kunz, Min. Resources of the United
States, 1902 4
4. Block of Limestone with Alternating Layers of Sulphur. From Ann. Rep.
U. S. National Museum, 1899 ao
5. Plan of Pyrite Lens. Louisa Co., Va. .'Uter Thos. Watson, Mineral Re-
sources of Virginia , 34
6. Section Showing Stringers of Pyriie Interleaved with Schist. Ibid 35
7. Map of Id Quimica Palronite Area, Minasragra, Peru. After D. F. Hewelt,
Bull. Am. Inst. Min. Eng.. 1909 4a
8. Crystals of Halite; Slassfurt, Germany. From Ann. Rep. U. S. National
Museum, 1899 45
9. Map of Petite Anse, Louisiana. After Hilgard 51
10. Section of Petite Anse, La. Ibid 5*
11. Crystals of Sylvite. From Ann. Rep. U. S. National Museum, 1899 54
II. Section of Fiuorite Vein, Chittenden Co., Ky. After W. S. T. Smith, Prof.
Papers, U. S. Geoi. Survey, No, 36 64
13- t^orundum Crystals. From Ann. Rep. U. S. National Museum, 1906 73
14. Ideal Section of Corundum Contact, Corundum Hill, Macon Co., N. C.
After J. H. Pratt, Bull. U. S. Geol. Survey 75
15. Map of Corundum Hill, North Carolina. Ibid y6
16. Map of Buck Creek Peridolite Area. Ibid 77
17. Map of Laurel Creek, Ca., Peridotite Area. Ibid 78
18. Map of Corundum ^reas of Canada So
ig. Map showing Location of Emery Deposit, Chester, Mass 85
to. Cross-section of Old Emery Mine, Chester 86
at. Map showing Geological Relation of Georgia and Alabama Baiudle Deposits.
Alter C. W. Hayes, Ann. Rep. U. S. Geol. Survey 98
aa. Section to show Residual Nature of Baurite Deposit. Ibid 99
33. Cross-section of Rutherford and Barclay Paint Mine, Lehigh Gap, Penn.
After C. E. Hesse loS
94. Ground Plan of Crjmora Manganese Deposhs. After C. E. Hall 136
15. Sections through Crimora l.Ianganese Deposits. Ibid [36
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UST OF ILLUSTRATIONS.
a6. Section of MongancK Deposit near Bahia, Brazil. After Biaoner, Trans.
Am. Inst, Min. F.ngs 13S
37. Map showing Mica -producing Areas of North Carolina. After Douglas
Sterrelt, Bull. 315, U. S. Geol. Survey, 1907 170
aS. Sections of Mica Veins, Yancey Co., N. C. Ahnt W, C, Kerr, Trans. Am.
Inst. Min. Engs., Vol. 8, 1880 171 ■
ag. Generalized Section of Mica Mine near Cusler, S. D. After D. Sterrett,
Bull. 380, U. S. Geol. Survey 174
30. Section through Lake Girard Mica Mine, Quebec, Canada. .After Cirkel.
Mica, Occurrence, Eiploilation and Uses 175
31. Section of Vein in Baby Mine. North Burgess, Ontario, Ibid 1 76
3s. Mtca-bearing Pyroxene Dike in Gneiss. An Illustration of Pocket Deposit.
After Cirkel. Ibid 177
33. Mica-bearing Pyroxene Dike in Limestone. Ibid. 178
34. Sectionof Asbestos-bearing Rocks, Thetford, Canada. After Cirkel, Asbestos,
Its Occurrence, Expk>it3tion and Uses iljo
35- MapShowingScrpentineAreasinEastemTownshipof Quebec. Ibid 190
36. Vertical Section Wall of Asbestos Pit, Black like, Canada 191
37. Bk>ck of Serpentine with Vein of Asbestiform Mineral. From Rep. U. S.
National Museum, 1899 191
38. Outlines of Garnet CrysUls 19S
39. Outlines of Zircon Cryauls 100
40. Section Showing Apatite Deposits in Wallingford Mica Mine. After Cirkel , 370
41. Seciion through Apatite and Mica Depodts, Templeton, Canada. Ibid 174
43. Map of Tennessee Phosphate Region. After C. W. Hayes, 17th Ann. Rep.
V. S. Geol. Survey 383
43. Seciion Showing Mode of Occurrence and Formation of Residual Phosphates
in Tenn. After C. W. Hayes, U. S. Geol. Survey 386
44. Typical Seciion, Lower Portion of Phosphate Beds, Montpelier, Idaho. After
F. B. Weeks, Bull. 315, U. S. Geol. Survey a88
45. Map of Monazite Areas in the Carolinas. After J. H. Pratt, Trans. Am.
Inst. Min. Engrs 305
46. Outlines of Vanadinite Crystals 314
47. Map of Chilean Nitrate Region. After Fuchsand De launey 318
48. Section of Tilted Borate Beds, Furnace Valley, California. After C. R. Keyei,
Bull. Am. Inst. Min. Engrs., 1909 335
49. Sketch Map of California Borax Localities. Ibid 336
50. Ide&l Section of Bennett Barile Mine, Pittsylvania Co., Va. After Watson
Mineral Resotlrces of Virginia 336
51. Sketch Map of Gila River Alum Deposit. After C. W. Hayes, Bull. 315, U.
. S. Geol. Survey 353
5*. Seciion Across Bullah.Delab Mountab, Showing Alunte Beds. After Pill-
man, Min. Resources N. S. Wales 35^
53. Plan of Pilch Lake, Trinidad. After S. F. Peckham 376
54. Section of Asphalt Vein East of Havana, Cuba. After R. C. Taybr 378
55. Section through Quarry of Gilson Paving Co. After G. H. EMrJdge, U. S.
Geol. Survey 380
ovGoo'^lc
THE NON-METALLIC MINERALS,
tXCLUSlVE OF GEMS, BUILDING STONES, AND MARBLES.
L THE ELEMENTS.
I. CARBON.
The numerous compounds of which carbon forms the chief
constituent are widely variable in their physical properties and origin.
As occurring in nature few of its members possess a definite chemical
composition such as would constitute a true mineral species, and
they must for the most part be looked upon as indefinite admixtures
in which carbon, hydrogen, and oxygen play the more important
r6Ies, For present purposes the entire group may be best con-
sidered under the heads of (i) The Pure Carbon series; ^s) The
Coal series, and (3) The Bitumen series, the distinctions being based
mainly on the gradually increasing amounts of volatile hydrocarbons,
a change which is accompanied by a variation in physical condition
from the hardest of known minerab through plastic and liquid to
gaseous forms. Here will be considered only the members of the
pure carbon series, the others being discussed under the head of
hydrocarbon compounds.
Diamond. — ^This mineral crystallizes in the isometric system,
with a tendency toward octahedral forms, the crystals showing curved
and striated surfaces. (Fig. i.) The hardness is great, 10 of Dana's
scale; the specific gravity varies from 3.1 in the carbonados to 3.5
in good clear crystals. The luster is adamantine; the colors, white
or colorless, through yellow, red, orange, green, blue, brown to black.
The transparent and highly refractive forms are of value as gems,
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THE NON-METALLIC MINERALS.
and can best be discussed in works upon this subject. We have
to do here rather with the
rough, confused cn-stal-
Hne aggregates or round-
ed forms, translucent to
opaque, which, though
of no value as gems, are
of the greatest utility in
the arts. To such forms
the name black diamond,
bort, and carbonado are
applied.
Origin and occur-
rence.— The origin of
the diamond has long
been a matter of dis-
cussion. A small pro-
portion of the diamonds
iits of gravel or sand. In
so-called blue gravel, formed.
F "-
i
§
i
9
i
9
L
— Diamomi crystals; characteristic forms.
[U. S. National Museum.]
of the world are found in alluvial de
the South African fields they occur in a
according to Lewis, along the line of contact between an eruptive
rock (peridot ite) and highly carbonaceous shales. They were
regarded by Lewis as originating through the crj'stallization of the
carbon of the shales by the heat of the molten rock. De Launay
states, however, that there is no necessary connection between the
shales and the diamond, and shows wilh apparent conclusiveness
that the latter occur often in a broken and fragmental condition,
such as to indicate beyond doubt that they originated at greater
depths and were brought upward as phcnocrj-sts in the molten
magma at the time of Us intrusion. The primary origin of the
diamonds he regards as through the crx'stallization, under great
pressure, of the carbon contained in the basic magma in the form
of metalhc carbides.
The diamond-bearing rock, i.e., the true parent rock, is now very
generally conceded to be the peridotite, and to which Lewis gave
the name kimberlUe.
The Brazilian diamonds come mainly from Minas Geraes and the
ovGoO'^lc
Paraguaca district, in the State of Bahia, where Ihey are found in
detrital material resulting from the breaking down of sedimentary
metamorphic rocks. These rocks, as described by Branner,'
belong to the La\TaI series of Carboniferous formations, and con-
sist of fake-bedded pinkish red sandstone, conglomerate and
quartzite. The washings yielding the diamonds are altogether
along streams that flow over these beds or their detrital ma-
SECTION OF KrMBERLEY MINE
. .':'^ae1gpiii-re.''''^--'-«o:.'.-l- Vy ■■ 7,-V;->ir„,K'„,.!'.„'' •' "^
Fig. 1. — Section of Kimberiey Diamond Mines,
[After Rennen.]
terials and there b apparently no doubt that they — and the
quartzite in particular — represent the parent rock. Cases of
finding of diamonds in the quartzite matrix have been reported,
but apparently need authentication. There are no eruptive rocks
in connection with the beds over the greater part of this
district, and the diamonds, so far as yet determined, cannot
be attributed to an igneous origin, Branner, however, notes
the exbtence of considerable areas of serpentine (altered peri-
dotite?) underlying the sedimentary series, and it is surmised as
possible that such may have been the original source of the
' Engineering and Mining Journal, LXXXVII, igog, p. 981.
ov Google
4 THE NON-METMLUC MINERALS.
diamonds themselves. The problem cannot be considered as yet
solved.
According to Kunz,' 95 per cent of all diamonds at present
Fig. 3. — Largest Known Black Diamond. Weight 3150 carats.
[U. S, Geological Survey.]
obtained come from the Kimberly Mines, Griqua Land, west South
Africa; of these, some 47 per cent are bort. The remainder come
from Brazil, India, and Borneo. A few ha\'e been found in North
America, the Ural Mountains, and New South Wales, but these
countries are not recognized as regular and constant sources of
supply. The .Australian diamonds, it may be noted, have been found
in igneous rocks, of the nature of diabase, or dolerite.^ Recently
' Gems and Precious Stones, New Yoj
> Geol. Mag., Vol. VI, Nov., 1909, p.
..Coo'^lc
diamonds have been reported from near Murfreesboro, in Pike
County, Arkansas, associated with peridotites imder much the same
conditions as in South Africa.
The largest known gem diamond is the Cullinan, found in 1905
in the Premier Mine, Transvaal, South Africa. This, before cutting,
measured roughly 4X21X2 inches and weighed 3,024! carats. The
largest black diamond, or carbon, is that shown approximately
natural size in F^. 3. Thb was found in the Paraguaca district
of Brazil in 1895, and weighed 3,078 carats.
Uses. — The material, aside from its use as a gem, owes its chief
value to its great hardness, and is used as an abrading and cutting
medium in cutting diamonds and other gems, glass, and hard materials
in general, such as can not be worked by softer and cheaper sub-
stances.
With the introduction of machinery into mining and quarrying
there has arisen a constant and growing demand for black diamonds,
or bort, for the cutting edges of diamond drills, and to a less extent
for teeth to diamond saws.
The crystallized diamond is not suitable for these purposes
owing to its cleavage property. The best bort or carbonado
comes, it is said, from Bahia, Brazil, where it is found as small,
black pebbles in river gravels. The ordmary sizes used for drills
weigh but from one-half to i carat, but in special cases pieces weigh-
ing from 4 to 6 carats are used. It is stated that the crowns of large
drills, 10 inches in diameter, armed with the best grade of carbonado,
are sometimes valued as high as $10,000.
BIBLIOGRAPHY.
M. Babiket. Tbe Diamond and other precious stones-
Report ot the Smithsonian Institution, 1870, p. 333.
A. DaubiSe. Annates des Mines, 7th Ser., IX, 1876, p. 130,
Remarking on the occurrence of platinum associated with petjdotites, he calls
attentioD 10 the fact that Maskel/ne had shown tbe diamonds of South AMca
and Borneo to occur in a decomposed peridotite.
OxvnxE A. Derby. Geology of the Diamantiferous Region of the Province ot
Faiant^ Brazil.
American Journal of Science, XVIII, 1S79, p. 310.
Geology of the Diamond.
American Journal of Science, XXIII, 1882, p. 97.
R. CoEBH- Igneous origin of the Diamond.
Proceedings, Manchester Literary and Philosophical Society, 1SS4, p. 5.
ov Google
6 THE NON-MBTALUC MINERALS.
H. Carvtll Lewis. The Genesis of the Diamond.
Science, VIII, i8S6, p. 345.
Gardner F. Williams. The Dimnond Mines of South Africa. ■
Transactions of the American Institute of Mining Engineen, XV, 1S86, p. jg^
Orville a. Debbv. The Genesis of the Diamond.
Science, IX, 1887, p. 57.
Discovery of Diamonds in a Meteoric Stone-
Nature, XXXVIl, 1887, p. no.
Diamond Mining in Ceylon.
Engineering and Mining Joumal, XLTX, 1890, p. 678-
A. Meevyn Suith. The Diamond Fields of India.
Engineering and Mining Journal, I.III, i8g2, p. 454.
Olives Whipple Humtihgtoh. Diamonds in Mclcorites.
Science, XX, 189J, p. 15.
Diamonds in Meteoric Stones.
The American Geologist, XI, 1893, p. a8a. (Abstract of paper by H. Moissan,
Comptes Rendus 1893, pp. 116 and 128.)
Henxi Moissan. Study of the Diamantiferous Sands of Brazil.
Engineering and Mining Joumal, LXII, i3q6, p. 333.
Henbv Carvill Lewis. I. Papers and Notes on the Genesis and Matrix of the
Diamond, edited by Prof. T. G. Bonney.
The Geological Magazine, IV, 1S97, p. 366.
Sir WiLLiAii Crooees. Diamonds.
Nature, LV, 1897, p. 3^5.
L. DZ Launav. Les Diamants du Cap.
Paris, 1897.
Okville a. Derbv. Brazilian Evidence on the Genesis of the Diamond.
Thejoumalof Geology, VI, 1898, p. III.
H. W. FuRMiSS. Carbons in Braxil. U. S. Consular Reports, iSgS, p. 604. See also
En^neering and Mining Journal, LXVI, 1898, p. 60S.
U. J. Klincke. Gites Diamantiiares de la R^publique sud-Africaine.
Annales des Mines, XIV, 1S98, p. 563.
Gabdheb F. WnxiAHS. The Diamond Mines of South Africa. The Macmitlan
Company, London, 1901.
George F. Kimz and H. S. Washington. Diamonds in Arkansas.
Transactions American Institute of Mining Engincera, XXXIX, 1908, p. 169.
J. C. Branneb. The Diamond-Bearing Highlands of Biatil.
Engineering and Mining Joumal, LXXXVII, 1909, p. gSi.
Victor Hartog. Petrographic Notes on the Diamond-bearing Peridotites of Kim-
berly, South Africa.
Economic Geologist, IV, No. 5, 1909, p. 438. This paper gives full bibliog-
raphy of African mines up to date.
Graphite. — Graphite, plumbago, or black lead, as it is variously
called, is a darii steel-gray to black lustrous mineral with a black
streak, a hardness of but 1.2, and a specific gravity of from 2.25 to
2.27. The prevailing form of the mineral is scaly or broadly foliated,
ov Google
ELEMENTS. 7
with a bright luster, but it is sometimes quite massive and columnar
or earthy, with a dull coal-like luster.
Its most characteristic features are its softness, greasy feeling,
and property of soiling everything with which it comes in contact.
Molybdenite, the sulphide of molybdenum, is the only mineral with
which it is hkely to become confounded. This last, however, though
very similar in general appearance, gives a streak with a slight
greenish tinge, and when fused with soda before the blowpipe yields
a sulphur reaction. Chemically, graphite is nearly pure carbon.
The name black lead is therefore erroneous and misleading, but has
become too firmly established to be easily eradicated.
The analyses given below show the composition of some of the
purest natural graphites.
L«»Utr.
Dirbon.
Aih.
Volatile
M,tt«.
98.817
99.791
97.6a6
99-815
0.180
■S94
.109
As mined the material is almost invariably contaminated by
mechanically admixed impurities. Thus the Canadian material as
mined yields from 22,38 to 30.51 per cent of graphite; the best
Bavarian, 53.80 per cent. The grade of ore that can be economi-
cally worked naturally depends upon the character of the impurities
and the extent and accessibility of the deposit. It is said' that
deposUs at Ticonderoga, New York, have been worked in which
there was but 6 per cent of graphite.
Occurrence and origin. — Graphite occurs mainly in the older
crystalline metamorphic rocks, both siUceous and calcareous, some-
times in the form of disseminated scales, as in the crystalline hme-
stone of Essex County, New York, or in embedded masses, streaks,
and lumps, often of such dimensions that single blocks of several
hundred pounds weight are obtainable. It is also found in the
form of true beds and veins.
The fact that the mineral is carbon, one of the constituents of
* EQi^aeenng and Mining Journal, LXV, 1898, p. 356.
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8 THE NON-METALLIC MINERALS.
animal and vegetable life, has led many authorities to r^ard it, like
coal, as of vegetable orgin. While this view is very ■ plausible it
can not, however, be regarded as in all cases proven.
That graphite may be formed independently of organic life is
shown by its presence in cast iron, where, on cooling, it has crys-
tallized out, in the form of bright metallic scales.
Carbon b also found in meteorites which are plainly of igneous
origin, and which have thus far yielded no certain traces of either
plant or animal remains. It is, however, a well-known fact that
coal — itself of organic origin — has in some cases been converted into
graphite through metamorphic agencies, and intermediate stages like
the graphitic anthracite of Newport, Rhode Island, afford good
illustrations of such transitions. Certain European authorities' have
shown that amorphous carbonaceous particles in clay slates have
been converted into graphite by the metamorphosing influence of
intruded igneous rocks. Prof. J. S. Newberry described an occur-
rence of this nature in the coal fields of Sonora, Mexico,' as follows:
" All the western portion of this coal field seems to be much broken
by trap dikes which have everywhere metamorphosed the coal and
converted it into anthracite. At the locality examined the metamorphic
action has been extreme, converting most of the coal into a brilliant
but somewhat friable anthracite, containing 3 or 4 per cent of volatile
matter. At an outcrop of one of the beds, however, the coal was
found converted into graphite, which has a laminated structure,
but is unctuous to the touch and marks paper hke a lead pencil.
The metamorphism is much more complete than at Newport (Rhode
Island), furnishing the best example yet Icnown to me of the con-
version of a bed of coal into graphite."
In New York State and in Canada, graphite occurs in Laurentian
rocks, both in beds and in veins, a portion of the latter being appar-
ently true fissure veins and others shrinkage cracks or segregation
veins which traverse in countless numbers the containing rocks. It is
said ' that in the Canadian regions the deposits occur generally in
' Beck and Luzi, Berichte der Deutschcn Chemischen Gesellschalt, 1S91, p. aj.
'School of Mines Quarterly, VIIl, 1887, p. 334.
' See On the Graphite of Ihc Laurentian ot Canada, by J. W. Dawson, Proceediags
ot the Geological Society of London, XXV, i8jo, p. iii, and an article on Graphite
by Prof. J. F. Kemp in The Mineral Industry, II, 1893, p. 335.
ovGoo'^lc
ELEMENTS. 9
limestone or in their immediate vicinity, and that granular varieties
of the rock, often contain large crystalline plates of the mineral.
At other times the mineral is so finely disseminated as to give a
bluish-gray color to the limestone, and the distribution of the bands
thus colored seems to mark the stratification of the rock. Further,
the plumbago is not confined to the limestones; lai^e crystalline
scales of it are occasionally disseminated in pyroxene rock or pyral-
lolite, and sometimes In quarizite and in feldspathic rocks, or even
in magnetic oxide of iron. In addition to these bedded forms,
there are also true veins in which graphite occurs associated with
caldte, quartz, orthoclase, or pyroxene, and either in disseminated
scales, in detached masses, or in bands or layers separated from
each other and from the wall rock by feldspar, pyroxene, and quartz.
Kemp describes' the graphite deposit near Ticonderoga, New York,
as in the form of a true fissure vein, cutting gametiferous gneiss,
which has an east and west strike. The vein at the "big mine"
runs north iz° west, and dips 55° west The vein filling is evidendy
orthoclase {or microciine) with quartz and biotite and pockets of
calcite. Besides graphite, it contains tourmaline, apatite, pyrite,
and sphene.
Walcott^ describes the graphite at the mines 4 miles west of
Hague, on Lake George, New York, as occurring in Algonkian
rocks, and as probably of organic origin.
At the mines the alternating layers of graphite shale or schist
form a bed varying from 3 to r3 feet in thickness. The outcrop may
be traced for a mile or more. The gunetlferous sandstones form a
strong ledge above and below the graphite bed. The appearance
is that of a fossil coal bed, the alteradon having changed the coal
to graphit-e and the sandstone to indurated, gametiferous, almost
quartzitic forms. The character of the graphite bed is well shown
in the accompanying plate (PI. I), from a photograph taken in 1890,
It is here a little over 9 feet in thickness and is formed of alternating
layers of highly graphidc sandy shale and schist.
' Prelimiiuiiy Report on the Geology of Essex County, Contributions from the Geo-
logical Departmeat o[ Columbia Collie, tS93, pp. 451, 453.
• Bulletin of the Geologiral Society ol America, X, 1898, p. ii?.
ovGoo'^lc
lO THE NON-METALLIC MINERALS.
F. L. Hess describes • the graphite of Santa Maria, Mexico, as
occurring in beds in sandstone which has been much folded and also
intruded by granitic dikes. There are at least seven beds of varying
thickness. The folding to which the enclosing sandstone has been
subjected has in many instances so squeezed the yielding graphite
as to form lenticular masses, in places upward of 20 feet in thickness
which within a short distance may pinch out to mere knife-like edges.
The wall rock of the mines, as may be surmised from the above, is
mainly sandstone, though sometimes of granite. The graphite is
wholly amorphous, but is said to be very pure. It would appear
to owe its origin to the metamorphism of beds of coal through the
intrusion of igneous rocks, as in the case described by Newberry.
According to J, Walther^ the Ceylonese graphite occurs in
coarsely foliated or stalky masses in veins in gneiss which, where
mined, is decomposed to the condition of laterite. The veins are
regarded as true fissures, and vary from 12 to 22 cm. (about 43 to
8J inches) in width.
The graphite of Northern Moravia occurs in gray to black
crystalline granular ArcJuean limestone interbedded with amphibo-
lites and muscovite gneiss, the limestone itself being often serpen-
tinous, in this respect apparently resembling the graphitic portions
of the ophicakites of Essex County, New York. The material is
quite impure, showing on the average but 53 per cent of carbon
and 44 per cent of ash, the latter being made up largely of siUca
and iron oxide, with a little sulphur, magnesia, and alumina. This
graphite is regarded as originating through the metamorphism of
vegetable matter included in the original sediments, the agencies
of metamorphism being both igneous intrusions and the heat and
pressure incidental to the folding of the beds.'
As to so much of the graphite as occurs in beds there seems,
then, little doubt as to its origin from plant remains which may be
imagined to have existed in the form of seaweeds or to have been de-
rived from diffused bituminous matter. The origin of the vein
material is not so evident, though it seems probable that it is due
' Ei^neering Magazine, XXXVIII, 1909, pp. 3^-48.
' Records of the Geologira! Survey of India, XXIV, iSqi, p. 41.
■ Jahrbuch k. k. Geologische Reicbsansult, 1897, XLVII, p. 11.
ovGoo'^lc
ELEMENTS. ii
to the metamorphism of bituminous matter segregated into veins,
like those of albertite in New Brunswick or of gilsonite, ia Utah.
Kemp states that the Ticonderoga graphite must have reached the
fissure as some volatile or liquid hydrocarbon, such as petroleum,
and become metamorphosed, in time, to its present state. Walther
believes the Ceylon material to have originated by the reduction
of carburetted vapors. (See also under origin of diamonds,
p. 2.)
The total quantity of carbon in the fonn of graphite in the Lauren-
dan rocks of Canada has been estima.ted by Dawson as equal to that
in the form of coal in any similar areas of the Carboniferous system of
Pennsylvania.
Sources. — The chief sources of the graphite of commerce are
Austria and Ceylon. Other sources of commercial importance are
Germany, Italy, Siberia, the United States, Canada and Mexico.
The chief deposits of commercial value in the United States are at
Ticonderoga, and Hague, N. Y.,and Clay County, Alabama, where
the material occurs in disseminated scales in a mica-free granite.
An earthy, unpure graphite, said to be suitable for foundry facings,
is mined near Newport, Rhode Island. In Chester County, Penn-
sylvania, the material is mined from deposits in mica schist. Other
American localities are: Bartow County, Georgia; Bloomingdale,
New Jersey; ClintonviUe, New York; Wake County, North Caro-
lina; Lehigh and Berkscounties, Pennsylvania; Salt Sulphur Springs,
West Virginia; St. Johns, Tooele County, Utah,
Neaj Centersville, Georgia, there is mined from open cuts a
graphitic schist consisting essentially of from 5 to lo per cent of
amorphous graphite and tajcose minerals, which presumably origi-
nated through the metamorphism of carbonaceous slates.
Graphite is a very common mineral in the Laurentian rocks of
Canada. The most important known localities are north of the
Ottawa River, in the townships of Buckingham, Lochaber, and
Grenville. At Buckingham it is stated masses of graphite have
been obtained weighing nearly 5,000 pounds. At Grenville the
graphite occurs in a gangue consisting mainly of pyroxene, wollas-
tonite, feldspar, and quartz, while the country rock is limestone.
ov Google
la THE NON-METALLIC MINERALS.
Blocks of graphite have been obtained weighing from 700 to 1,500
pounds, '
Graphite is also found in Japan, Australia, New Zealand, Green-
land, Guatemala, Germany, and in almost all the Austrian provinces,.
the most important and best known deposits being those of Kaiser-
berg at St, Michel, where there are five parallel beds occurring in
a grayish-black graphite schist, the beds varying from a few inches
to 6 yards. The only workable deposit in Germany is stated to be
at Fassau in Bavaria. The material occurs in a feldspathic gneiss,
seeming to take the place of the mica. The beds have been worked
chiefly by peasants for centuries, and the output used mainly for
crucibles.*
Uses. — Graphite is used in the manufacture of "lead" pencils,
lubricants, stove blacking, paints, refractory crucibles, and for
foundry facings. In the manufacture of [lencils only the purest
and best varieties are used, and high grades only can be utilized for
lubricants. For the other purposes mentioned impure materials can
be made to answer. In the manufacture of the Dixon crucibles,
a mixture of 50 per cent graphite, 33 per cent of clay, and 17 per
cent of sand is used.
The low grade graphitic material obtained from graphitic schbts,
near Centersville, Georgia, is used as a "filler" in the manufacture
of fertilizers, it being claimed for it that it prevents absorption of
moisture, and incidental caking.
Preparation. — In nature graphite is usually associated with harder ■
and heavier materials, which it is necessary to eliminate before
the material is of value. In New York it b the custom to crush
the rock in a battery of stamps, such as are used in gold milling,
and then separate the graphite by washing, its lighter specific gravity
permitting it to be floated off on water, while the heavy, injurious
constituents are left behind. Mica, owing to its scaly form, can not
be separated in this manner, and hence micaceous ores of the mineral
are of little if any value,
' Descriptive Catalogue of Economic Minerals of Canada, 1S76, p. 139.
• The Journal of the Iron nod Steel tnstitute, 189a, p. 739.
ovGoo'^lc
ELEMENTS
13
Prices. — The value of the mineral varies whh its quality. In
1907 the crude lump was reported as worth $S a ton and the pulver-
ized $30.
The annual output as given ' for the principal countries is as fol-
lows:
world's PKODCCnON o
Voir.
Auslri*.
Canada.
M«ico.
Gennany,
India.
It&ly.
Si'S
'90°
1907
Metric
33^663
Metric
Itms.
1.743
Metric
tons.
3.»3
Metric
9.148
4,033
Metric
tons.
1,858
'AT
Metric
9, 7 JO
9,160
Metric
i,86j
Ceylon produced in 1906, 36,578 Ions. Some 7,000,000 pounds of graphite are
produced artificially by the International Graphite Company, at Niagara Falb,
New York.
BIBUOGRAPHY.
J. W. Dawson. On the Graphite of the Laurentian of Canada-
Quarterly Journal Gcolc^cal Society of London, XXVI, 1870, p. 113.
M. BoNNETOY. Mimoire sur la Otologic et I'Esploiiatioa des Gtles de Graplute de
la Boheme MSridionale.
Annales des Mines, 7th Ser., XV, 1879, p. 157.
JoBN S. Newberry. Tiie Origin of Grapliite.
School of Mines Quarterly, VIII, 1887, p. 334.
Der Graphitbcrgbau auf Ceylon.
Berg- und Huttenmannische Zeitung, XLVII, 18S8, p. 323.
J. Waltheh. Ueber Graphit^nge in lereetitcm Gneiss (Laterit) von Ceyloo.
Zeitschrift der Dculschen Geologischen Gesellschafl, XLI, 1889, p. 359.
A. Paii-mjsch. Die Graphitbergbaue im stldlichen Bohmen.
Berg- und Huttenmarnisches Jahrbuch. XXXVII, 1889, p. 95.
T. ,^NDRKS. Graphite Mining in Austria and Bavaria, (Abstract.)
Journal of the Iron and Steel Institute, 1890, p. 738.
J. P0STI.ETHWAITE. The Borrowdale Plumbago; its Mode of Occurrence and
Probable Origin.
Proceedings of the Geological Society of London, Session, 18S9-90, p. 114.
On ihe formation of Graphite in contact -melamorphism.
American Journal of Science, XLII. 1891, p. 514. Review of article in Be-
richte der Deutschen Chemiachen Gesellschaft, XXIV, p. 1884, 1891.
■ The Mineral Industry, VI, 1S97; VIII, 1S99.
ov Google
14 THE NON'METALUC MINERALS.
W. Lvzt. Zur Kenntniss des Graphitkohletistoffes. CSetichte der Deutschen
Chemischen Gesellschaft, XXIV, pp. 4085-4095. 1891.)
Neues Jahrbuch fUr Mineralogie, Geologic und Faleontologie. 1S93. II, Part
3, p, J41. (Abstract.)
E. Weinschene. Zur Kcnntiiiss der Graphitlagerstfttten. Chcmiscb-geologischc
Studieo von Dr. Emst Weinschenk.
I. Die Graphitlagecsl^tten des bayerischen Grenzgebirges. Habilitations-
schrift zur Erlangung der venU Icgendi an der K. technischen Hochschule.
MOnchen, 1897.
Fkamz Kbetschuer. The Graphite Deposits of Northern Moravia.
Transactions of the North of England Institute of Mining and Mechanical
Engineering, XLVII, 1898, p. 87.
2. SULFHUK.
The color of this mineral when pure is yellow, sometimes brownish,
reddish, or gray through impurities. Hardness, 1,5 to 3.5. Specific
gravity, 2.05. Insoluble in water or acids. Luster resinous. It
occurs native in beautiful crystals, or in massive, stalactitic and sphe-
roidal forms. Once seen the mineral b as a rule readily recognized,
and all possible doubts are set at rest by its ready burning with a
faint bluish flame and giving the irritating odors of sulphurous anhy-
dride. In nature it is often impure through the presence of clay and
bituminous matters, and sometimes contains traces of selenium or
tellurium.
Origin and mode of occurrence. — Sulphur deposits of such extent
as to be of economic importance occur as a product of volcanic
activity, or result from the alteration of beds of gypsum. On a
smaller scale, and of interest from a purely mineralogical standpoint,
are the occurrences of sulphur through the alteration of pyrite and
other metallic sulphides.
As a product of volcanic action sulphur is formed through the
oxidation of hydrogen sulphide (H,S), which, together with steam
and other vapors, b a common exhalation from volcanic vents and
solfataras. Such de[>osits on a small scale may be seen incrusting
fumaroles in the Roaring Mountain or associated with the sinter
deposits of the Mammoth Hot Springs in the Yellowstone Park. It
may also be produced through the mutual reaction of hydrogen
sulphide (H^) on sulphuric anhydride (SO,), the product beirg
sulphur (S) and water (HjO) as before. To these types belong the
ovGoO'^lc
sulphur deposits of Utah, CaUfomia, Nevada, and Alaska in the
United States, as well as those of Mexico, Japan, Iceland, and other
volcanic regions. Sulphur is derived from the sulphate of lime (gyp-
sum or anhydrite) through the reducing action of organic matter.
The sulphate, through the loss of its oxygen, becomes converted into a
sulphide, which, through the carbonic acid in the air and water,
becomes finally reduced to hydrt^en sulphide with the formation of
calcium carbonate.
According to Fuchs and De Launay' there is formed at the same
time with the hydrogen sulphide, a polysulphide, which in its turn
yields a precipitate of sulphur and carbonate of lime. The maxi-
mum amount of sulphur which would thus result from the decompo-
sition of a given amount of g3^sum is stated to be 24 per cent. This
method of origin is illustrated in the celebrated deposit of Sicily,
where the sulphur occurs partially disseminated through and partly
interbedded with a blue-gray limestone. Beneath the sulphur beds
as they now exist are found the remnants of the older gypseous beds,
which through decomposition have yielded the materials for the lime
and sulphur beds now overlying.
With these Sicilian sulphurs occur a number of beautiful secondary
minerals, as celestite, calcite, aragonite, and selenite.
Sulphur derived directly from metallic sulphides is of little
economic interest. Kemp states' that masses of pyrite in the cal-
ciferous strata on Lake Champlain may yield crusts of sulphur an
inch or so thick, and it is not uncommon to find small crystals of
the mineral resulting from the alteration of galena, as described by
George H. Williams,' at the Mountain View (Maryland) lead mine.
The minute quantities of sulphur found in marine muds are
regarded by J. Y. Buchanan* as due to the oxidation of metallic
sulphides, which are themselves produced by the action of animal
digestive secretions on preexisting sulphates, mainly of iron and
manganese.
Localities. — ^The principal localities of sulphur known in the
United States are, in alphabetical order: Alaska, California, Idaho,
' Traite des Giles Minf raux et Mf talUftres, I, p. 259.
*The Mineral Industry, II, 189J, p. 585.
' Johns Hopldna Univeisiy Qrculars, X, 1891, p. 74.
'Proceedings of the Koyal Society of Edinburgh, XVIII, 1890-91, p. 17.
ov Google
i6
THE NOH-MET^LUC MINERALS.
Louisiana, Nevada, Texas, Utah, and Wyoming. With the possible
exception of those of Louisiajia, these may all be traced to a solfataric
origin. The Alaskan deposits,' according to Dall, are best developed
on the islands of Kadiak and Akutan. California deposits have in
times past been worked at Clear Lake, in Modoc County, in Colusa
Coimty, in Tehama County, and in Napa County. The Louisiana
deposits lie in strata of Quaternary Age, and are derived from
gypsum. The following facts relative to this deposit are from Pro-
fessor Kemp's paper, already alluded to:
Probably the richest and geographically the most accessible of
the American localities is in the southwestern part of the State, 33^
miles west of New Orleans and 12 miles from Lake Charles. The
first hole which revealed sulphur was sunk in search of petroleum.
While more or less bituminous matter was revealed by the drill, the
great bed of sulphur is the main object of interest, A number of holes
have since been put down with the results recorded below, leaving
no doubt but that there is a very large body which awaits exploitation.
The first explorations were made by the Louisiana Petroleum and
Coal Oil Company, This was succeeded by the Calcasieu Sulphur
and Mining Company. The Louisiana Sulphur Mining Company
followed, and finally the American Sulphur Company, The records
of 8 holes are appended. Nos. i and 2 are about 150 feet apart.
Nos. 2, 3, and 4 were put down in :886,
T BOIE-HOLES T
T HAVE PENETRATED THE SULPHUR B
No...
Gnaet'i Wells.
^S-
Anwrkui Sulphur
Cmpany.
No...
No.».
No. 4.
No. 6.
No. J.
No. 8.
Clay, quicksand, and gravrl. . .
333
680
3
4a6
70
"I
5S
345
91
57
35°
95
"S
3'
370
30
499
44
Sulphur bed, 70 to 80 per cent.
Gjpsum and suJphur
Depth of b(Jc in f>M
1,331
SSa
6»
S>5
603
602
598
!9«
I. Stopped in sulphur.
* Alaska and its Resources, Boston, 1870.
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Analyses from the large bed in holes No. 2 and No. 3 gave the
following:
503 feel. .
533 fe"- ■
54g feet. .
The difficulties in development which have, however, been largely
overcome, lie in the quicksands and gravel, which are wet and soft,
and in the soft rock {hole i), which yields sulphurous waters under a
head, at the surface, of about 15 feet.
Sulphur deposits, supposedly due to the oxidation of sulphuretted
hydrogen, occur over wide areas in northern El Paso and Ree\es
counties in Texas. The country rock b limestone and the sulphur
wholly superficial and associated with g)'psum or loosely consolidated
detritus of the nature of sand and gravel.
Nevada. — The Nevada deposits occupy the craters of extinct
hot springs near Humboldt House. These craters or cones are
described by Russell ^ as situated on the open desert, above the surface
of which they rise to a height of from 20 to 50 feet.
Nearly all of the cones are weathered and broken down, and
are all extinct. The outer surface of the cones is composed of cal-
careous tufa and siliceous sinter, forming irregular imbricated sheets
that slope away at a low angle from the orifice at the top. The
interiors of these structures are filled with crystalline gypsum, which
in at least two instances is impregnated with sulphur. One of the
cones has been opened by a cut from the side in such a manner as
to expose a good section of the material filling the interior, and a few
tons of the sulphur and gypsum removed. The percentage of sul-
phur is small, and the economic importance of the deposit somewhat
doubtful. The cone that has been opened is surrounded on all sides
' Transactions of the New York Academy of Sciences, I, 1881-1882, p, 172.
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i8 THE N0N-MET.4LUC MINERAIS.
by a large deposit of calcareous and siliceous material, thus forming
a low dome or crater, with a base many times as great in diameter
as the height of the deposit. These cones correspond in all their
essential features with the structures that surround hot springs that
are still active in \'arious parts of the Great Basin, thus leaving no
question as to their origin. They are situated within the basin of
Lake Lahontan, and must have been formed and become extinct
since the old lake evaporated away.
Sulphur is reported as occurring in the chemically formed deposits
that surround Steamboat Springs, situated midway between Car-
son and Reno, Nevada, and in the Sweetwater Mountains, on the
boundary between California and Nevada. The extent and geolog-
ical relations of these last mentioned deposits are unknown.
Another Olustration of deposits of the volcanic type is that fur-
nished by the Rabbit-Hole Sulphur Mines. These are located in
northwestern Nevada, on the eastern border of the Black Rock
Desert, and derive their name from the Rabbit-Hole Springs, a
few miles to the southward. The hills bordering on the east are
mainly of rhyolite, with a narrow band of water-laid volcanic tuff
along the immediate edge of the desert. At the mines the angular
fragments of volcanic rock, have been cemented by opal and other
siliceous infiltrations since their deposition, so that they now form
brittle siliceous masses, with pebbles and fragments of older rocks
scattered through them. In many places these porous tuffs and
breccias are richly charged with sulphur, which fills all the interstices
and sometimes lines large cavities with layers of crystals 5 or 6 feet
in thickness. In the Rabbit-Hole District sulphur has been found
in quantities for a distance of several miles along the border of
the desert, but the distribution is irregular and uncertain, and is
always superficial, so far as can be judged by the present openings.
The sulphur has undoubtedly been derived from a deeply seated
source, from which it has expelled by heat, and escaping upward
along the lines of faulting, has been deposited in the cooler and
higher rocks in which it b now found, though whether the deposi-
tion took place by direct sublimation or through the decomposition
of hydrogen sulphide can not now be told with certainty. Judging
from the siliceous material that cements the tuffs, it is evident that
b/Goot^lc
ELEMENTS. 19
the porous rocks in which the sulphur is now found were pene-
trated by heated waters bearing sLica in solution previous to the
deposition of the sulphur. The mines occur in a narrow north-
aod-south belt along a line of ancient faulting which b one of the
great structural features of the region. The absence of a recent
fault-scarp, together with the fact that the mines are now cold and
do not give off exhalations of gas or vapor, shows that the solfataric
action has long been extinct, though at the Cove Creek Mines, men-
tioned below, the deposition Ls still in progress. . i.
Utah. — Several sulphur deposits occur in central Utah, in and
about Sulphurdale, a small mining camp some twenty miles north
of Beaver. The best known of these are the Cove Creek beds,
situated about four miles south of Cove Fort. The deposits have
been exploited in an itinerant way for over thirty years, but their
full extent is not as yet known. They have been described by G.
Vom Rath,' A. F. Du Faur,^ and W. T. Lee.^
The country is one of late Quaternary volcanic activity, and the
sulphur, which is evidently due to the oxidation of exhalations of
hydrogen sulphide, occurs filling the interstices of volcanic tuffs —
in part rhyolitic — and in horizontal sheets, cracks and fissures in
the same. The material occurs in all degrees of purity, that which
is worked varying from 15 to 85 per cent sulphur. The average
output of the region is given as about 1,000 tons. Vom Rath esti-
mated the capacity of the Cove Creek deposit as some 1,300,000
tons.
Skily. — Of the foreign localities of sulphur, the most noted at
present are those of Sicily and Japan. The first-named deposits
are described as occurring in Miocene strata involving, from below
up, sandy marls with beds of salt, limy marls and lignite, gyp-
sum and limestone impregnated with sulphur, black shales, and
micaceous sands. Overlying all these is a white, marly Pliocene
limestone, while below the Miocene is the Eocene nummulitic
limestone. The sulphur is found in veinlets and sometimes in
' Keues Jftbrb. fOr Min. u. Pet., I, i88), pp. 139-68.
'Transactionsofthe American Institute of Mining Engineers. XVI, 1888, pp. 33-35.
' Bulletin 315, 1904, U. S. Geological Survey, pp. 485-89.
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9o THE NOri-METALLIC MINERALS.
larger masses, which ramify through the cellular limestone, as shown
in Fig. 4.
The yield in sulphur varies from 8 to 25 per cent, rarely running
as high as 40 per cent Below 8 per cent the rock can not be worked
economically. More or
less petroleum and bit-
umen are foimd in the
mines. Barite and celes-
tite sometimes accompany
the sulphur.
The mining regions
are in the southern cen-
tral portion of the island ;
Girgenti and Larcara are
the chief centers. The
mines are distributed over
an area of 160 to 170
Fig. 4. — Block of limestone (light) wiih alter- i.:i„.„„, /„i, ,
imiing bands of sulphur (daSi). SicLlv. kJometers (about 100
[U. S. National Miiseum.) miles) from east to west,
and 85 to 90 kilometers
(55 miles) from north to .south. They occur in groups around
centers, partly because the sulphur-bearing stratum is not continu-
ous, and partly because the sulphur indications are concealed by
later deposits. The region is miiih faulted.
Japan. — The Japanese sulphur deposits are all of volcanic origin,
and the Abosanobori Mine, in Kushiro village, Kawakami-gori,
Kushiro Province, Hokkaido, may be taken as fairly typical. The
mine is on a conical-shaped mountain of augite andesite which, on
its northern side, b open and looks down upon a plain covered with
lava, and is shut in by the walls of the old crater on the other sides.
Sulphur b found in different parts of these walls in massive heaps,
and sulphurous fumes still issue nearly everj-where about the mines.
The ore as taken from the mines carries from 35 per cent to 90 per
cent of sulphur, which b extracted by steam refining works at Hyocha,
some 35 miles dbtant.'
' The Mining Industry of Japan, by Wada Tsunashiro, 1893.
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ELEMENTS. »
Other Japanese localities are: The Aroya Mines, at Onikobe
village, Rikiizen Province, and the active volcano of Icvo-San, in
Yezo.
In addition to these localities may be mentioned the following,
'lU alphabetical order; Austria, Celebes, Egypt, France, Greece,
Hawaii, Iceland, Italy, Mexico, New South Wales, New Zealand,
Peru, Russia, Spain, and the West Indies.
Extraction and preparation. — Sulphur rarely occurs in nature in
any quantity sufficiently pure for commercial purposes. In freeing
it from its impurities three methods are employed: (i) Melting,
(2) distillation, and (3) solution. In the first the ore is simply dry
roasted at a low temperature or treated with superheated steam
unto the sulphur melts and nms off. The process is extremely
wasteful. A process of fusion in a calcium chloride solution has
come into use of late years, and bids fair to yield better results than
either of the above. In the distillation process the ore is heated
in iron retorts until the sulphur distills off and is condensed in
chambers prepared for it. The product is mosdy in the form of
"flower of sulphur." The method is expensive, but the resultant
sulphur very pure. In the third process mentioned the ore is treated
with carbon disulphide, which dissolves out the sulphur and from
which it is recovered by evaporation. This method, whfle giving
good results, is also expensive and somewhat dangerous, owing to
the explosive nature of the gases formed.*
Uses. — Sulphur is used mainly for the making of sulphuric acid,
though small amounts are utilized in the manufacture of matehes, for
medicinal purposes, and in the making of gunpowder, fireworks, in-
secticides, for vulcanizing india rubber, ete. In the manufacture ol
sulphuric acid the sulphur is burned on a grate to sulphurous anhy-
dride (SO2) which is then conducted with a slight excess of ah into
lai^ lead-lined chambers and mixed with steam and nitrous fumes,
where the SOj is oxidized to the condition of SO3 (sulphuric anhy-
dride) and takes up water from the steam, formmg H3SO4 (sulphuric
acid). Ordinary roll sulphiu* is quoted in the current price-lists at
from 1} to 2} cents per pound. (See also under iron pyrites, p. 32.)
■ The Mineral iDduMr^, II, 1S93, p. 600.
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THE NON-METALUC MINERALS.
BIBLIOGRAPHY.
R. PuMPKLLY. Sulphur in Japan.
Geological Researches tn China, Mongolia, and Japan. Smithsoman Condi*
buttons, XV, 1867, p. II.
I. C. Russell. Sulphur DeposiCs of Utah and Nevada.
Transactions of the New York Academy of Science, I, 18S1, p. 168.
A. Faber du Faub. The Sulphur Deposits of Southern Utah.
Transactions of the Americaii Institute Mining Engineers, XVI, 18B7, p. 33.
The Sulphur Mines of Sicil)'.
Engineering and Mining Journal, XLVI, iSSS, p. 174.
V< LuuNTiA. Sulphur Mines of Sidly.
U. S. Consular Report No. 108, 1889, pp. 146-15S-
3. ARSENIC.
This substance occurs native in the form of a brittle, tin-white
metal, with a specific gravity of 5.6 to 5.7 and a hardness equal to
3,5 of the scale. On expKKure it becomes dull black on the imme-
diate surface' It is found, as a rule, in veins in the older crystalline
rocks associated with antimony and ores of gold and silver. Some
of the more celebrated localities for the mineral, as given by Dana,
are the silver mines of Freiberg, Annaberg, Marienberg, and Schnee-
berg in Saxony; JoacMmsthal in Bohemia; Andreasberg in the
Harz; Kapnik ajttd Orawitza in Hungary; Kongsberg in Norway;
Zmeiv in Siberia; St. Maria aux Mines, Alsace; Mount Coma
dei Darden, Italy; Chafiarcillo, Chile; San Augustin, Hidalgo,
Mexico, and New Zealand. In the United States it has been found
at Haverhill, New Hampshire; Greenwood, Maine; near Leadville,
Colorado; and on Watson Creek, Frozen River in British Columbia.
The arsenic of commerce is, however, rarely obtained from the
native mineral, but is prepared by the ignition of arsenical pyrites
(FeAsi) or arsenical iron pyrites (FeSjjFeAsj). The white arsenic
of commerce (arsenious acid, As,0,), though occurring sometimes
native as ai^enolite in the form of botryoidal and stalactitic crusts
of a white or yellowish color, is, as a rule, obtained as a by-product
in the metallurgical operations of extracting certain metals, particu-
larly cobalt and nickel, from their ores. Such ores as Niccolite,
a nickel arsenide (NiAs), Gersdorffite NiAsS), Rammelsbergite
(NiAsj), Smaltite (CoAs,), Skutterudite (CoAs,), Proustite (Ag^S,),
and other arsenides and sulpharsenides on roasting give up their
ovGoO'^lc
SULPHIDES AUD ARSENIDES. ^3
arsenic in the form of fumes, which are condensed in chambers
prepared for this purpose.
Uses. — Arsenic is utilized in the form of arsenious acid (As,Oj)
in dyeing, calico printing, in the manufacture of various pigments,
in arsenical soaps, in the preparation of other salts of arsenic, and
as a preservative in museums, particularly for the skins of animals
and birds. See further on p. 32.
II. SULPHIDES AND ARSENIDES.
I. REALGAK AND OBPIMENT.
Realgar is a monosulphide of arsenic, AsS, = arsenic, 70.1 per
rant, sulphur, 29.9 per cent. Hardness, 1.5 to 2; brittle; specific
gravity, 3.55; color, aurora-red to grange-yellow; luster, resinous;
streak the color of the mineral. Orpiment, or auripigment as it
is also called, is a trisulphide of arsenic of the formula As,Sj, =
arsenic, 61 per cent, sulphur, 39 per cent. Hardness and specific
gravity essentially the same as realgar, with which it is commonly
associated.
Occurrences. — Realgar and oipiment are very beautiful, though
not abundant minerals which occur associated with ores of silver
and lead in the various mining regions of Japan, Hungary, Bohemia,
Transylvania, and Saxony, They have been reported in the United
States in beds of sandy clay beneath lava in Iron County, Utah,
and form the so-called "arsenical gold ore" of the Golden Gate
Mine, Mercur, Tooele County, this same State, also in San Bernar-
dino County, California; Douglas County, Oregon, and in minute
quantities in the geyser waters of the Yellowstone National Park,
The realgar and orpiment of the Coyote mining district. Iron
County, Utah, occur in a compact, sandy clay, occupying a horizontal
seam or layer about 2 inches thick, not distinctly separated from the
day, but lying in its midst in lenticular and nodular masses. The
bulk of the layer consists of realgar in divergent, bladed crystab,
closely and confusedly aggregated, sometimes forming groups of
brilliant crystalline facets in small cavities toward the center of the
mass. The orpiment is closely associated with the realgar in the
ov Google
S4 THE NON-MET^LUC MINERALS,
form of small and delicately fibrous crystalline rosettes and small
spherical aggregations made up of fine radial crystals, and also in
bright yellow, amorphous crusts in and around the mass of the
realgar. Fine parallel seams of gypsum occur both above and below
the layer, and the strata of arenaceous clays above for 30 feet or more
are charged with soluble salts which exude and effloresce upon the
surface of the bank, forming hard crusts- The whole appearance
and association of the minerals indicates that they have been formed
by aqueous infiltration since the deposition of the beds.'
Orpiment is said * to occur at Tajowa, near Neusohl, Hungary,
as nodular masses and isolated crystals in ciay or calcareous marl.
Uses. — Realgar is used mainly in pyrotechny, yielding a very
brilliant white light when mixed with saltpeter and ignited. It is
now artificially prepared by fusing together sulphur and arsenious
add.* Orpiment is used in dyeing and in preparation of a paste
for removing hair from skins. According to the British consular
reports there were exported from Baghdad in 1897, some 55,600
pounds of the mineral for use as a pigment. As with realgar, the
mineral is now laigely prepared artificially. The name orpiment
is stated by Dana to be a corruption of aurtpigment, golden paint,
in allusion to the color.
BIBUOGRAPHY.
W. P- Blake. Occurrence of Realgar and Orpiment in Utah Territory.
American Journal of Science, XXI, 1881, p. 319.
H. B. Fulton. Arsenic in Spanish Pyrites, and its elimination in the local treat*
ment for production of capper precipitate.
Journal of the Society of Chemical Industry, V, 1SS6, p. 396.
Production of Arsenic in Cornwall and Devon.
Engineering and Mining Journal, LII, 1S91, p. 96.
William Thouas. Arsenic.
The Mineral Industry, II, 1S9J, p. 35.
' W, P. Blake, American Journal of Science, XXI, i88r, p.
'H. A. Mien, Mineialogicai Magaane, July, 189a, p. 34.
•Wagner's Chemical Technolt^, p. 87.
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SULPHIDES MND MRSENIDBS.
2. COBALT MINERALS.
Several minerals contain cobalt as one of their essential con-
stituents in sufficient quantity to make thetn of valu6 as ores. In
other cases the cobalt exists in too small quantities to pay for working
for this substance alone, and it is obtained as a by-product during
the process of extraction of other metals, notably of nickel- The
common cobalt-bearing minerals, tt^ether with their chemical com-
position, mode of occurrence, and other characteristics, are given
below:
Cobaltite. — Cobaltine, or cobalt glance. This is a sulphar-
senide of cobalt of the formula CoAsS, — sulphur, 19.3 per cent;
arsenic, 45.2 per cent; cobalt, 35.5 per cent; hardness, 5.5, and
specific gravity 6 to 6.3. The luster is metallic and color silver-
white to reddish. When in crystals, commonly in cubes or pyrito-
hedrons. Analysis of a massive variety from I, Siegen, Westphalia;
II, Skutterud, Norway, and III and IV, Daschkessan, in the
government of Elizabethpol, Caucasus, as given by various authori-
ties, yielded results as below:
I-
II.
III.
IV.
45-3'
(9-35
33-7'
1.63
43-46
20.08
33-"'
3-23
35-97
31-73
17.90
1-44
44-»6
'7-55
9 -85
o.a6
40.7'
In Saxony the mineral occurs in lodes in gneiss and in which
heavy spar (barite) forms the characteristic gangue. It is associated
with other metallic sulphides, notably those of lead and copper. At
Skutterud and Snarum, Norway, the cobaltiferous fahlbands, accord-
ing to PhiUips, " occur in crystalUne rocks varying in character be-
tween gneiss and mica schists, but from the presence of hornblende
they sometimes pass into hornblende schists; among the accessory min-
erals are garnet, tourmaline, and graphite. These schists, of which
' Ore Deposits, by J. A. Phillips, p. 389.
ovGoo'^lc
36
THE NON-METMLUC MINERALS.
the Strike is north and south, and which have an almost perpendicular
dip, contain fahlbands very similar in character to those of Kongs-
berg. The ores worked are cobalt glance, arsenical and ordinary
pyrites, containing cobalt, skutterudite, magnetic iron pyrites, copper
pyrites, molybdenite, and galena. Nickel ores do not accompany
the ores of cobalt at this locality in any appreciable quantity. The
principal fahlband is known to extend for a distance of about 6
miles, and is bounded on the east by a mass of diorite which pro-
trudes into the fahlband, while extending from the diorite are small
dikes or branches traversing it in a zigzag course. It is also inter-
sected by dikes of coarse-grained granite which contain no ore, but
which penetrate the diorite."
The Skutterud Mine in 1879 produced 7,700 tons of cobalt ore,
which yielded 108 tons of cobalt concentrates containing from 10
to II per cent of cobalt, worth about ;^ii,ooq.
At Daschkessan the ore occurs under a sheet of diabase, the
cobaltite being in the wall rock of this sheet, which carries also
garnets and copper pyrites. In 1887, 1,216 kilograms of the mineral
were extracted ; in 1888, 928 kilograms, and in 1889, 1 2,960 kilograms,
besides some 3,000 kilograms of cobalti'erous matter obtained in
treating the cobaltiferous copper ores.'
Smaltite. — This is essentially a cobalt diai^nide of the formula
CoAsy = arsenic, 71,8 per cent; cobalt, 28.2 per cent; hardness, 5.5
to 6; specific gravity, 6.4 to 6.6. Color, white to steel-gray. Through
the assumption of nickel the mineral passes by gradations into
chloanthite.
Analyses of samples from (I) Schneebeig, Saxony, and (II) Gun-
nison County, Colorado, as given by Dana, yielded results as below
Comtitueats.
Sulphur
Cobalt
:b,Got>^lc
SULPHIDES AND ARSENIDES. a?
The mineral occurs like cobaltite in veins associated with other
metallic arsenides and sulphides.
The name safflorite is given to a cobalt diarsenide closely resem-
bling smaltite, but differing in being orthorhombic, rather than iso-
metric in crystallization. The composition as given by Dana is
quite variable, running from 6i per cent to 70 per cent arsenic, and
10 to 23 per cent cobalt, with 4 to 18 per cent of iron and smaller
amounts of sulphur, copper, nickel, and bismuth. It is found
associated with smaltite in various localities.
Skuttemdite is the name given to a cobaltic arseniae of the
formula C0AS3, =• arsenic, 79.3; cobalt, 20.7. It is of a tin-white
color, varying to lead-gray, has a hardness of 6, and specific gravity
of 6.72 to 6.86. It occurs associated with cobaltite, titanite, and
hornblende in a vein in gneiss at Skutterud, Norway.
Glaucodot is a sulpharsenide of cobalt and iron of the formula
(Co,Fe) AsS, = sulphur, 19.4 per cent; arsenic, 45.5 per cent;
cobalt, 23.8 per cent; iron, 11.3 per cent. Color, grayish; hardness,
5; specific gravity, 5.9 to 6. Actual analysis of a Chilean variety
yielded (according to Dana) As 43.2, S 20.21, Co 24.77, Fe "-QO. It
is therefore essentially a ferriferous cobaUite, that is, a cobaltite in
which a part of the cobalt has been replaced by iron. The mineral
is foimd at Huasco, Chile, associated with cobaltite in a chloritic
schist. The name alioclasite is given to a variety of glaucodot con-
taining bismuth and answering to the formula Co(As,Bi)S. The
composition as given is somewhat variable. Arsenic, 28 to 33 per
cent; bismuth, 23 to 32 per cent; sulphur, 16 to 18 per cent; cobalt,
20 to 24 per cent; iron, 2.7 to 3.8 per cent. It is reported only
from Orawitza, Hungary.
Linnsite is a sulphide of cobalt with the formula CojS^, = sul-
phur, 42.1 percent; cobalt, 57,9 per cent; a part of its cobalt is com-
monly replaced by nickel, giving rise to its variety siegeniie. The
mineral is brittle, of a pale steel-gray color, tarnishing red. Hard-
ness, S-S and specific gravity, 4.8 to 5. When crystallized it is com-
monly in octahedrons. The following analyses of a nickel-bearing
variety (siegenile) are qiioted from Dana:
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THE NON-METALUC MtNERALS.
ConstituooU.
S.
CO.
Ni.
Pe.
Cu.
41.00
39-7°
41-54
43.86
15.69
39.56
30-53
S.31
1.96
3-37
Ji
Mineral Hill, Mao-land. .
Mine La MoCte, Missouri.
The mineral occurs in gneiss in Sweden; with barite and siderite
a MUsen; in limestone with galena and dolomite at Mine La Motte,
Missouri, and with sulphides of iron and copper in chloritic schists
in Maryland.
Sycbnodyinite has the fonnula (Co,Cu),Sj, and yields sulphur,
40.64 per cent; copper, i8.g8 per cent; cobalt, 35.79 per cent;
nickel, 3.66 per cent; iron, 0.93 per cent. It is of a steel-gray color,
metallic luster, and has a specific gravity of 4.75.
^ythrite or cobalt bloom is the name given to a hydrous
cobalt arsenate of the formula Co,As,Oi+ 8H,0, = arsenic pentoxide,
38.4 per cent; cobalt protoxide, 37.5 per cent, and water, 24.1 per
cent. It occurs in globular and reniform shapes and earthy masses
of a crimson to peach-red color associated with the arsenides and
sulpharsenides mentioned above and from which it is derived by a
process of oxidation. In Churchill County, Nevada, it occurs as
a decomposition product of a cobalt-bearing niccolite. It is also
found at the Kelsey Mine, Compton, in Los Angeles County, Cali-
fornia; associated with cobaltite at Tambillo and at Huasco, Chile,
and under similar conditions in various parts of Europe.
Asbolite or earthy cobalt, is a black and earthy ore of man-
ganese (wad) which sometimes carries as high as 30 per cent of
cobaltic oxide. It takes its name from the Greek aapokaivoo, to
soil like soot. Boselite is an arsenate of lime, magnesia, and cobalt
with the formula (Ca,Co,Mg),As20g,2HjO, = arsenic pentoxide,
51.4 per cent; lime, 28.1 per cent; cobalt protoxide, 12-5 per cent;
water, 8 per cent. It is of a light to dark rose-red color; hardness,
3.5; specific gravity, 3.5 to 3.6, and vitreous luster. Sphsero-
COlmltite is a cobalt protocarbonate of the formula CoCO^ = carbon
dioxide, 37.1 per cent; cobalt protoxide, 62.9 per cent. It is also of
a rose-red color, varying to velvet-black. Hardness, 4, and specific
gravity, 4.03 to 4- 13. It occurs but sparingly, associated with roselite
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SULPHIDES AND ARSENIDES. 39
at Schneeberg in Saxony. Remiogtonite is a hydrous carbonate
the exact composition of which has not been ascertained. Cobalto-
menite is a supposed selenide of cobalt. Biebeiite, or cobalt
vitriol, is a sulphate of the formula CoSO,+ 7HjO. The color is
flesh to rose-red. It is soluble in water, has an astringent taste,
and occurs in secondary stalactitic form. Pateraite is a possible
molybdate of cobalt.
Aside from the possible sources mentioned above, cobalt occurs
very constantly associated with the ores of nickel (niccolite, millerite,
chloanthite, etc.), and is obtained as a by-product in smelting. Con-
siderable quantities have thus from time to time been obtained from
the Gap Mines of Pennsylvania, Mine La Motte, Missouri, and
Lovelock, Nevada. Certain gold-copper mines in the Quartz-
burg district. Grant County, Oregon, are also producers. The
nickel mines of New Caledonia are perhaps the most pro-
ductive. The ore here, a silicate, carries some 3 per cent of cobalt
protoxide.
A vein of cobalt ore near Gothic, Gunnison County, Cotorado,
is described as lying in granite, the gangue material being mainly
caldte, throughout which was disseminated the ore in the form of
smaltite. With it were associated erythrite, a small amount of iron
pyrites, and native silver. An analysis of this ore yielded as below:
Aisetuc 63-81
Sifica a.6o
Lead a.oS
Sulphur I - 55
Bismuth. .
Nickel..."
Silver. . , .
94-89
A cobalt ore, consisting of a mixture of glaucodot and erythrite,
occurring near Carcoar Railway Station, New South Wales, has the
composition given below:
ovGoO'^lc
THE NON-METALLIC MINERALS,
CooatituenU.
Moisture . :
Metallic arsenic
Metallic cobalt. .. .'.
Metallic nickel
Metallic irOD
Alumina
Metallic mai^anese
Metallic calcium. .
MagneMum
Gold
Silver
Sulphur
Gangue (insoluble in adds). .
1.4S0
Trace.
Trace.
According to the Annual Report, Department of Mines, for
1888, this ore occurs concentrated in irregular hollows and bunches,
often intimately mixed with dioiite in a line of fissure between an
intrusive diorite and slate, the fissure running for some distance follow-
ing the line of junction between the two rocks, and being presumably
formed at the time of the extrusion of the diorite.
Other cobalt ores, carrying from 13 to 15 per cent of cobalt oxide,
occur near Nina.*
Uses. — Cobalt is produced and sold in the form of oxide and
used mainly as a coloring constituent in glass and earthem wares.
Only some 200 tons are produced annually the world over. The
market value of the material is variable, but averages about $3 a
pound.
BIBUOGRAPHy.
FUCHS er Db Ladmay. Tnut£ des Gttes Miniiaui, II, pp. 75-91.
3. ARSENOPVBrTE; UISFICKEL; OK ARSENICAL PYRITES.
Composition. — Somewhat variable. Essentially a sulpharsenide
of iron of the formula FeAsS, or FeS,, FeAs,, = arsenic, 46 per cent;
sulphur, 19.7 per cent, and iron, 34,3 per cent. The name danaite
is given to a cobaltiferous variety. The specific gravity of the mineral
'Complete analyses of these are given in Catalogue o( the New South Wales
Exhibit, World's Columbian Exposition, Chicago, 1S93, p. 33a.
. Coo'^lc
SULPHIDES. AND ARSENIDES.
31
varies from 5.9 to 6.2. Hardness, 5.5 to 6. Colors, silver-white
to steel-gray; streak, dark gray to black ; luster, metallic. Brittle.
Occurrence and uses. — See under LoUingite.
4. LOLLmOITE; LEUCOPYRITE.
The prismatic arsenical pyrites, or leucopyrile, is esseotially a
diarsenide of iron, with the formula FeAs2, though usually contami-
nated with a little sulphur and not infrequently cobalt, bismuth, or
antimony. It has a specific gravity of 7 to 7.4, hardness of 5 to 5.5,
metallic luster, and silver-white to steel-gray color. Either lollingite
or arsenopyrite can be readily recognized by the strong odor of
garlic given off when roasted.
Occurrence and uses. — Arsenopyrite and l6llingite both occur
commonly in crystalline rocks and associated with other metallic
arsenides and sulphides, and with ores of gold, silver, tin and lead.
Mispickel is itself at times highly auriferous and forms a valuable
ore of gold as in New South Wales, California and Alaska. Both
minerals, often associated with the alteration product scorodiie,
occur in veins intersecting the older crystalline rocks m Orange,
Putnam and Essex coimties. New York. Near Kent, in Putnam
County, the vein is in gneiss and consists of a white quartz gangue
with varying proportions of the arsenide and iron pyrites. It has
a northerly strike, and is in close proximity and runs parallel with a
dike of basic igneous rock, though there is no apparent connection
between the two. Hand-sorted samples of this ore yielded:
CooititueoM.
Per Cent.
a.90
36.11
a. 17
J3.73
36.Q0
suTpC;,cs"'.v.".:::::;;:::::;
99.90
Near Menville and in other places in Orange County, arsenopy-
rite— associated with leucopyrite and the hydrous arsenate scoro-
dite — occurs in crystalline limestone. Near Christiansburg, Mont-
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3 a THE NON-METALLIC MINERALS.
gomery County, Virginia, granular mispickel occurs intimately
associated with iron p)Tites in quartz schist.
That these arsenides could be utilized as sources of arsenic is
apparent. As a matter of fact, however, a very large portion of
the arsenic of commerce is obtained as a by-product in the smelting
of arsenical ores of gold, silver, copper, etc., and still larger quanti-
ties might thus be obtained — more, indeed, than the market demands
— did smelters arrange to condense and save the fumes from their
smelters. It has been stated that from the stacks of the Washoe
smelter (at Anaconda, Montana) there escaped during each day of
August, 1905, some 57,270 pounds of arsenic;* in fact, that from
this smelter alone the waste arsenic at that time eitceeded six times
the entire domestic output In spite of these abundant sources of
supply in the western mining regions, proximity to market and
other advantages have favored a moderate developiaent elsewhere.
In Putnam County, New York, ore from a lode varying from 12 to
30 feet in width is mined and from it a product obtained averaging
25 per cent of metallic arsenic. Recent developments have also
been made in the Virginia deposit noted. Aside from that of the
white arsenic of the druggists the material app>ears in the market in
form of a variety of salts and industrial preparations, as Sheep dip,
Paris Green, London Purple, etc. Some 1,700 long tons of white
.arsenic were produced in this country in 1907 and 5,000 tons im-
ported.
5. PYRITES.
Two forms of the disulphide of iron are common in nature.
The first, known simply as pyrite or iron pyrites, occurs in sharply
defined cubes and their crystallographic modifications, or in granular
masses of a brassy-yellow color.
The second, identical in composition, crystallizes in the orthorhom-
bic system, but is more common in concretionary, botryoidal, and
stalactitic forms, which are of a dull grayish-yellow color. This form
is known as marcasite or gray iron pyrites. Both forms have the
* Journal of AmericaD Chemical Socieljr, XIX, 1907.
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SULPHIDES AND ARSENIDES.
33
chemical composition, FeS2,=iion, 46.6 per cent and sulphur, 53.4
per cent.
The ore as mined is, however, never chemically pure, but con-
tains admixtures of other metallic sulphides, besides, at times, con-
siderable quantities of the precious metals. The foUowing analyses'
of materials from well-known sources will serve to show the general
variation :
CoDstituents.
I.
II.
III.
IV.
V.
VI.
VII.
Sulphur
48.0
48.0
I'.b
"■S
3.7
48.01
41.01
40.00
35.00
4.00
47-76
43.99
3-69
1.99
46.40
39-00
1.50
9-»S
3-75
li;S
^PP"
7.60
10.00
8.70
Trace.
Trace.
Trace.
Trace,
Lead. . .
0.64
I, Milan, Coos County, New Hampshire; II. Rowe, MassachusettEi III. Louisft
County, Virginia; IV. Sherbrooke, Canada; V. Rio Tinto, Spain; VI. near Lyons,
Fraoce; VII. Westphalia, Germany.
Pyrite is sufBciently hard to scratch glass, and this, together with
its color, crystalline form, and irregular fracture, is sufficient for
its ready determination in most cases. Once known, it is thereafter
readily recognized. Owing to its yellow color, the mineral has by
ignorant persons been mistaken not infrequentiy for gold — ^which,
however, it does not at all resemble— and has hence earned the not
very flattering but quite appropriate name of "fool's gold." In
certain cases, however, it carries the precious metals, and in many
regions is sufficiently rich in gold to form a valuable' ore.
Mode of occurrence and origin. — Pyrite is one of the most widely
disseminated of minerals, both geologically and geographically,
occurring in rocks of all kinds and of all ages the world over. It is
foimd m the form of disseminated grains throughout the mass of a
rock, or along the line of contact between basic eruptives and sedi-
mentaries; as irregular and sporadic and concretionary masses in
sedimentary rocks and modem sands and gravels; iii the form of
■ Mineral Resources of the United States, 1883-1884, p. 877.
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34 THE NON-METMLUC MtSERALS.
true fissure veins, and as interbedded, often lenticular masses,
sometimes of immense size, lying conformably with the strat-
ification (or foliation) of the inclosing rock. On the immediate
surface the mineral is in most cases considerably altered
by oxidation and hydration, forming the caps of gossan or
limonite.
The origin of the mineral in the older crystalline rocks,
as that of the rocks themselves, is not infrequently somewhat
obscure. In sedimentary rocks it is undoubtedly due to the
precipitation of the included ferruginous matter by sulphureted
and deoxidizing solutions from decomposing animal and vegetable
matter.
At the Stella mine, DeKalb Junction, St. Lawrence County,
New York, the country rock b a light gray gneiss, the well-marked
Fig. 5. — Plan of pyrite lens, Louisa County, Virginia, (o) Pyrite; (ft) schist.
[After Thos. Watson, Mineral Resources of Virginia,]
foliadon showing a strike of N. 20" to 30° E,, and dipping 20° to
30° to the northwest It b probably a sheared igneous rock of
pre-Cambrian age. At the mine the gneiss incloses a band of fine-
grained, dark-colored schbt 15 to 20 feet in width. This is also
regarded as an; altered igneous rock intrusive in the gneiss. The
pyrite occurs in a series of overlapping lenses in thb schbt.
These may vary from 200 to 250 feet in length, with an average
thickness of 12 feet. The lump ore, as shipped, carries some
35 per cent of sulphur. The average mill ore carries but some 27
per cent, which amount is brought up to 44 or 45 per cent by
careful concentration.
Pyrite outcroppings are found in Louba and Prince William
counties, Virginia, over an area some t\vo miles in length. The ore
occurs in the form of lenses (see Figs, g and 6), often of large size,
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SULPHIDES ^ND ARSENIDES. 35
in crystalline schists, the largest thus far reported in Louisa County
being 700 feet in length with a maximum thickness of 60 feet, and in
Prince William County, 1,000 feet in length with a width of 10 feet.
They are stated ' by Watson to conform in dip and strike with the
schists, which in Louisa County is 60° to 6$° to the southeast, and
north 10° to 20" east; for Prince William County the dip is 25°
to 55° to the northwest, the strike remaining the same. The contact
between the ore bodies and the country rock is described as unusually
sharp, though occasional gradations are met with. Thin layers
of grayish white limestone often occur interlaminaled with the
schists and sometimes in close juxtaposition with the ore bodies.
Fic. 6. — Section showing slringen of pyrile (a) interleaved with schist (h).
[After Tbos. Watson, Mineial Resources of Viiginis.]
Dr. Watson is disposed to regard the pyrite as having originated
through a process of replacement of some of these limestone bodies
by sulphides.
The ore is massive and consists of fine, and, at times, very compact
aggregates of granular pyrite. As mined it averf^es from 43 to 45
per cent sulphur.
At Rio Tinto, Spain,^ the ore is described as occurring in immense
masses several thousand feet in length, and from 300 to 800 feet
in wklth, extending in depth to an unknown distance. The
ore is very clean and massive, containing besides sulphur and
iron only some 2 to 4 per cent of copper and traces of silver
and gold. The material is mined wholly from open cuts and
' Mineral Resourcts of Virginia, p. 190.
' A Visit to the Pyrites Mines of Spain, Eng. and Min. Jour., LVI, 1893, p. 498-
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36 THE NQN-METALUC MINERALS.
to a depth of some 400 feet The country rock is described
as of Silurian and Devonian schists, the ore occurring near
contact with diorites.
Uses. — With the exception of the small amount utilized in
the preparation of vermilion paints almost the sole value of
the pyrite is for the manufacture of sulphiuric acid and the
sulphate of iron, known a^ green vitrol or copperas. In the
process of making sulpliuric acid the ore is roasted or burnt
in specially designed ovens and furnaces until the mineral is de-
composed, the sulphur fumes being caught and condensed in
chambers prepared for the purpose. By the Glover and Gay-
Lussac method from 380 to 390 parts of sulphuric acid of a
density of 66° Baufn^ may be obtained for each 100 parts of sul-
phur in the ore, or about 2,565 pounds of acid to one ton (2,000
pounds) of average ore.
According to F. Stolba,' the so-called Bohemian fuming sul-
phuric acid is made from vitriol obtained from Silurian pyritiferous
schists ("vitriolschiefer"). The method as given is as follows:
Large masses of the schist, which consist essentially of a quartzose
matrix containing pyrite, carbonaceous matter, and clay, are exposed
to the weathering action of the atmosphere for three years. The
products of oxidation so formed are ferrous sulphate and sulphuric
acid, which latter acts energetically upon the clay, and finally alu-
minum sulphate and other sulphates are yielded. The ferrous sul-
phate at first formed becomes by oxidation ferric sulphate, which,
together with the aluminum sulphate, is the principal product of
the weathering of the vitriol slate. Ferrous sulphate remains only
in small quantities. The next operation is lixiviation of the mass
with water, after which the liquor obtained is concentrated to a
density of 40" Baum6, and finally evaporated in pans until, on
cooling, a crystalline cake of vitriol stone is obtained. The vitriol
stone is now calcined in order to remove the greater part of its water.
The resulting product, when heated to a very high temperature in
day retorts, yields sulphuric anhydride, and a residue, termed
' Journal o( the Society of Cliemical Industry, V, iSS6, p. 30.
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SULPHIDES AND ARSENIDES.
colcothar, remains in the retorts. The composition of vitriol stone
and colcothar will be seen from the following analyses : '
Fe,0, 20.07 Fe,{SO.V
A1,0^ 4.67 AUSO.),
FeO 0.64 FeSOi
MnO Traces. MgSO,
CaO 0.14 CaSO,
MgO 0.39 CuSO,
K,0 0.07 K,SO,
Na-0 0.05 Na^O,
CuO o.io HjSO,
SiO, 0.10 MnO, As, «ndP,0, .
jr*\Jt . - ' ,-.... i.ntceS' oju,_.
SO, 40-51 H,0..
H,0 3a-S"-99'3a
OOLCOTHAS.
Pe,0, 74.61 SO,...
\l,0, "-53 3HJ, 1,17
MgO 3-23 Cud 0.30
■CaO 0.83 HjO 1.30 — 99.04 ■
Pyrite on decomposing in the presence of moisture in the ground
sometimes gives rise to an acid sulphate of iron. This may attack
aluminous minerals when such are present, giving rise thus to solutions
■^f sulphate of iron and alumina, which come to the surface as "alum
springs," or, if no alumina is present, merely as iron or chalybeate
springs, which are of more or less medicinal value. The presence
of such sulphates in a soil is readily detected by the well-known
astringent taste of green vitriol and alum, even where the quantity
is not sufficient to appear as a distinct efHorescence. Impregnation
of these salts in soils are by ignorant persons sometimes assumed
to be of great medicinal value, and the writer has in mind a case
in one of the Southern States, in which the aqueous leachings of such a
soil were regularly bottled and sold as a specific for nearly all the
il!s to which the flesh is heir, though prescribed especially for flux,
wounds, and ulcers. (See also under Alum, p. 350.)
In the manufacture of copperas the ore is broken into small pieces
and thrown into piles over which water is allowed to drip slowly. A
* The Geology of England and Wales, p. J79.
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THE NON-METALLIC MINERALS.
natural oxidation takes place, whereby the sulphide b transformed
into a hydrated sulphate. The latter being soluble, runs off in
solution in the water, which must be collected and evaporated in order
to obtain the salt. Thus prepared the sulphate is used in 'dyeing,
in the manufacture of writing-ink, as a preservative for wood, and as
a disinfectant. It has also been used in the manufacture of certain
brands of fertflizers.
The analysis given below show (i) the composition of fresh
pyrite from the Coal Measures of Mercer County. Pennsylvania,
and (2) and (3) that of two varieties of paint produced from it by
calcination.*
CoMtitucoU.
I.
U.
IIL
96.. 6,
Trace.
0.41s
.697
6.300
.160
13- "o
9-195
0.405
77-143
-543
7-334
5-194
■653
-45°
Water and carbonaceoui m&tter
,.9.6
roo.ooo
.00.000
100.000
6, PYRRHOTrrE: magnetic pvrites.
This form of iron sulphide differs from either of the pyrites just
described not merely in the relative proportions of sulphur and iron,
but in its bronze color and property of being attracted by the magnet.
Moreover it does not show flie cubic crystal forms of pyrite and in-
deed is rarely found in crystals at all.
' Report M. M. Second Report of Progress in the Laboralory of the Survey at
Harrisburg, Second Geological Survey of Pennsylvania, 1879, p. 374.
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SULPHIDES AND ARSENIDES. 39
The content in sulphur (38 to 39 i>er cent) is too small to make
it of immediate value in the manufacture of sulphuric acid. It is
stated, however, that in certain cases, as at the Sudbury nickel mines
where the mineral occurs so closely associated with ores of other
metals as to necessitate a common treatment for all, the sulphurous
fumes from the roasters can be economically condensed and utilized
in the ordinary way. It is a safe prediction that in the not very
distant future the mineral must be utilized as an ore of iron.
BIBLIOGEIAPHY.
W. H. Adams. The Pjrites Deposits of Louisa CoTinty, Virginia,
Transactions of the Ameiicaa Institute of Mining Engineers, XII, 1SS3, p. 517.
WiLLiAH Mastvn. Pyrites.
Mineral Resources of the United States, 1883-84. P- S77.
J. H. Collins. The Great Spanish Pyrites Deposits.
EngineeiiQg and Mining Journal, XL, 1S85, p. 79.
E. D. Peters. A Visit to the Pyrites Mines of Spain.
Engineering and Mining Journal, LVI. 1893, p. 498.
Frank L. Nason. Origin of the Iron Pyrites Deposits in Louisa County, Virginia.
Engineering and Mining Joumal, LVII, 1894, p. 414.
M. Drillon, The Pyrites Mines of Sain-Bel.
Minutes of Proceedings of the Institute of Civil Engineers, CXIX, 1894-95,
p. 470.
7. MOLYBDENITE,
Thb is a disulphide of molybdenum having the formula MoSg, =
sulphur, 40 per cent; molybdenum, 60 per cent.
The mineral, like graphite, occurs in black, shining scales,
sometimes hexagonal in outline and with a bright metallic luster.
It is soft enough to be readily impressed with the thumb nail, and
leaves a bluish-gray trace on paper. On procelain it leaves a lead-
gray, slighdy greenbh streak. This faint greenish tinge, together
with its property of giving a sulphur reaction when fused with soda,
furnishes a ready means of distinguishing it from graphite, which
it so closely resembles. Through alteradon it sometimes passes
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40 THE NON-METALLIC MINERALS.
over into molybdite or molybdic ocher, a straw-yellow to white
ocherous mineral of the formula M0O3, = oxygen, 33.3 per cent;
molybdenum, 66.7 per cent.
Occurrence. — The mineral has a wide distribution, occurring in
embedded masses and disseminated scales in granite, gneiss, syenite,
crystalline schists, quartz, and granular limestone. It is found in
Norway, Sweden, Russia, Saxony, Bohemia, Austria, France, Peru,
Brazil, England, and Scotland, throughout the Appalachian region
in the United States and Canada, and in various parts of the Rocky
and Sierra Nevada Mountains. In Okanogan County, Washington,
the mineral occurs in beautiful large flakes in an auriferous quartz
vein transversing slates.
At Crown Point, in Chelan County, this same State, molybdenite
occurs in a nearly horizontal quartz vein cutUag a gray biotite granite,
the mineral itself being in the form of crystals and flakes 20 mm.
or more in diameter, and in small seams extending through the
quartz in all directions.^ In British Columbia it has been reported ^
as occurring in massive veins sometimes 8 inches in width. At
Cooper, Washington County, Maine, the mineral is found in dikes
of pegmatite cutting granite and also in the granite itself adjacent to
the dikes. The pegmatites, in this instance are regarded as approx-
imately contemporaneous with the granite, representing the latest
crystallization of the granitic magma, and the molybdenum sulphide,
an original constituent of the magma, crystallizing early during the
process of cooling.^
On Quetachoo-Manicouagan Bay, on the north side of the Gulf
of St, Lawrence, the mineral is reported *_as occurring disseminated
in a bed of quartz 6 inches thick, in the form of nodules from i to 3
inches in diameter, and in Sakes which are sometimes 12 inches
broad by i inch m thickness. It is also found in the form of finely
disseminated scales or small bunches among the iron ores of the
Hude Mine at Stanhope, New Jersey, sometimes constituting as
high as 2 per cent of the ore.
' A. R. Crook, Bullelin Geological Sociely of America, XV, 1904, p. iSj.
> Journal Canadian Mining Instituie, VII, 1904, p. 164.
* G. O. Smith, Bullelin 26, U. S. Geological Survey, 1904,. p. 19E.
' Geology of Caoada, iS6j, p. 754.
0 Got>^lc
SULPHIDES AND ARSENIDES. 41
Molybdenum is also a consti.uent of the mineral wulfenite, or
molybdate of lead.
Uses. — The principal use to which molybdenite has as yet been
put is in the preparation of molybdates for the chemical laboratorj'.
It b stated that a fine blue pigment can be prepared from it, which
it has been proposed to use as a substitute for indigo in dyeing silk,
c»tton, and linen. The metal molybdenum is produced but rarely,
and only as a curiosity, and has a purely fictitious value. Up to
the present time there has been no constant demand for the mineral
nor regular source of supply.
8. pateonite: vanadium sulphide.
The name patrtmite or Rizo-patronita has recMitly (1906) been
applied to a peculiar amorphous asphaltic-appearing material,
nearly black in color, breaking with a smooth to uneven and irregular
fracture and which analyses show to be essentially a vanadium sul-
phide, though in nature almost universally admixed with silica,
alumina, iron oxides and other impurities.
Composition. — The composition of the crude material as given
"by different authorities is as below:
I
II.
III,
10.8S
3.8s
It
54-06
6.88
a, 00
3.9J
4.5° I
11 11
t'4
Fe ::"
0-33
Trace
S-63'
1.90
9.88-
100.00 gj.jo'
■"■~
:. LarflBly arbooBCBOus.
I. CooUlmd «lto Ni. 1.87: C. 3
The formula for the minerals as suggested by these analyses is
somewhat uncertain, but may be VS*. With the patronite occurs an
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43 THE NON-MET^LUC MINEMLS.
asphaJtic compound, to which the name Quisqueile has been given;
a coke-like, material yielding some 86.63 P^ <^s"t f''^ carbon; a
little free sulphur; an iron-nickel sulphide and the impurities noted
in the analyses.
Occurrence. — Although vanadium-bearing hydrocarbons are not
uncommon, material of the composition and character indicated has
thus far been reported only from Minasragra, some 46 kilometers
Fig. 7. — Map of La Quimira patron ite area, Minasagra, Peru.
[Aflei D. F. Hewetl, Bulletin American Institute of Mining Engineers, 1909.]
from Cerro de Pasco in Peru, The region is one occupied by Jura-
trias and Cretaceous shales, sandstones, and limestones dipping
toward the northeast, much faulted and injected by dikes of trachyte,
andesite, dolerite, diabase, and quartz porphyry. The entire vana-
dium-bearing deposit consists of a lens-shaped mass occupying one
of the faults. The maximum width is some j8 feet and the length, so
far as ascertained, 350 feet, with a strike N. 20° W., and dip of 75° W.
This lens-shaped mass b composed mainly of three constituents,
(i) quisqueite, a black, lustrous -hydrocarbon of a hardness of 4.5
and specific gravity of 1.75; {2) a dull black, coke-like hydrocarbon
ovGoc^lc
of a hardness of 4,5 and specific gravity of 2.4; and (3) the patronite.
The relative position of these is shown in Fig, 7.
Origin. — No satisfactory explanation of this deposit is as yet at
hand. Very probably the entire deposit may have been formed as
have other asphaltic vein masses in Utah and elsewhere, i.e., the
material was forced into the shales while in a plastic condition.
It is conceivable, writes Hillebrand, that the injected material
was originally homogeneous and that segregation took place sub-
sequently.
Uses. — ^The material is roasted to drive off the volatile con-
stituents and the residue used as a source of vanadium salts for
metallurgical purposes.
BIBUOGR.\PHY.
D. Foster Hewett, Transactions of ihe .American Institute of Mining Engineers,
Febniary, 1909, pp. 191-316. (Vanadium Deposits in Peru.)
W. F. HU.1.EBRANI). The Vanadium Sulphide, Palronile, and its Mineral Associates.
From Minasraga, Peru.
Journal American Chemical Soeietv, XXIX, July, 1907.
I, halite; sodiuu chloride; or common salt.
Composition. — XaCl, = sodium, 60.6 per cent; chlorine, 39.4 per
cent. The natural substance is nearly always more or less impure,
as noted later. Hardness, 2.5; specific gravity, 2,1 to 2.6 per cent.
Colorless or white when pure, bjit often yellowish or red or purplish
from the presence of metallic oxides and organic matter. Readily
soluble in cold water, and has a saline taste. Crystallizes in the
isometric system, usually in cubes, rarely with octahedral modifi-
cations. The faces of the crystals (particularly when prepared
artificially) are often cavernous or hopper-shaped. Sometimes
occurs in fibrous forms, which it has been suggested are pseudo-
morphous after fibrous gypsum. Often found in the form of
massive, crystalline granular aggregates commonly known as rock
salt.
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44 THE NOfi-METALUC MINERALS.
Sylvite, the chloride of potassium, sometimes occurs associated
with halite, where it has formed under similar conditions. From
halite it can be distinguished by its crystalline form, that of a com-
bination of cube and octahedron (see Fig. ii), and more biting taste.
Owing to its ready solubilitj' it is rarely found in a state of nature.
Bischofite, the chloride of magnesium, is still more soluble and prac-
tically unknown except in crystals artilically produced.
COMPOSITION ot sAtT m
MV
won
S LOCALITIES.
Vari«i« of Salt.
i
I
ilk
H
i
I
■c
I
If
1^
1
1
.2
1
^
Authoritia.
Kxk sail.
06. J6
M
...J Tr.
BischoC.
oiSu
i:i>
i;;.
G. H. C'->li.
C. B. Havden.
GoesKnian.
0.
G. H. Cooli.
si:
SiSSiii.--
■■■■|°o'
r:
oiis
O.Oi
0.07
Sta tail.
0.5KJ
0.S4O.J4
0.14
tM
cad^"?: :::;::::: :;:::::
0.48
'■4-1
t'*l'°""n
11 ""-
"■ibS
11:
::::
SaU f™. ipring! and latcj
Dienie, 6eTTnan Lorraine. . .
GodiTieh. Ontario
£'S.S;S,;::::;:::
Ho<;l;ing Valley. Ohio
I . so.Goc^iian.
....,o.i>c,«i..
;:; R
°:!°l.:.::
;:oi
;,4o!Gof5smaTi.
Origin and occurrences. — Sodium in the form of chloride, to which
is commonly given the simple name of salt is one of the most widely
disseminated of natural substances, and not infrequently occurs in
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H^UDES. 45
such quantities interstratified with other rocks as to assume propor-
tions of geological importance. It b to the material occurring in
this form that the name rock salt is commonly applied. As existing
to-day the principal deposits of the world are a result of evaporation
of seawaters or deposits from springs. In either case the ultimate
source of the material was probably the same, the springs simply
deriving their supply from pre-existing beds of marine origin. Inas-
Fic. 8. — Cluster of halite crystals. Stassfurt, Germany.
[U, S. National Museum.]
much as seawaters carr)' in solution other salts than sodium chloride,
so it happens that the beds of marine salt are almost invariably con-
taminated or interstratified with carbonates, chlorides, and sulphates
of various substances which have been deposited in the inverse order
of their solubilities as e\-aporation proceeded. The following list
includes the more common associations: (i) carbonates of lime and
magnesia in the form of limestones, marls, and dolomites; (2)
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46 THE NON-METALLIC MINERALS.
sulphate of lime in the form of anhydrite and gypsum; (3) chlo-
ride of sodium, or common salt, and these followed in regular order
by the sulphates of magnesia and soda (Epsom salt and Glauber's
salt) and the chlorides of potassium and magnesium. These last
are, however, so readily deliquescent that they are rarely found
crystallized out in a state of nature, as above noted.
Such having been the method of formation, it is scarcely necessary
to state that salt beds are not confined to strata of any one geological
horizon, but are to be found wherever suitable circumstances have
existed for the formatbn and preservation. The beds of New
York State and of Canada and a part of those of Michigan lie among
rocks of the Upper Silurian Age. They are regarded by Professor
Newberry as the deposits of a great salt lake or sea that formerly oc-
cupied central and western New York, northern Pennsylvania, north-
eastern Ohio, and southern Ontario, and which he assumed to have
been as large as Lake Huron, or possibly Lake Superior. Apart of the
Michigan beds, on the other hand, were laid down near the base of
the Carboniferous series, as were also those of the Ohio Valley, and
presumably those of Virginia, while those of Petite Anse, Louisiana,
are of Cretaceous, or possibly Tertiary Age. The beds of the West-
em States and Territories are likewise of recent origin, many of them
being still in process of formation.
The English beds at Cheshire, the source of the so-called "Liver-
pool" salt, are of Triassic Age, as are also those of Vic and Dieuze
in France, Wurtemburg in Germany, and Salzburg in Austria,
while those of Wieliczka in Austrian Poland, and of Parajd in
Transylvania are Tertiary.
Salt is now manufactured from brines or mined as rock salt in
fifteen States of the American Union. These, in the order of their
apparent importance, are Michigan, New York, Kansas, California,
Louisiana, Illinois, Utah, Ohio, West Virginia, Nevada, Pennsyl-
vania, Virginia, Kentucky, Texas, and Wyoming. At one time
Massachusetts was an important producer of salt from sea waters.
The industry has, however, been gradually languishing, and may
ere now be wholly extinct. In Cahfomia salt is obtained largely
from sea water, but also from salt lakes and salines. In Michigan,
Ohio, the Virginias, Pennsylvania, and Kentucky salt is obtained
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H^UDES.. 47
from brines obtained from springs or by sinking wells into the salt-
bearing strata, while in New York, Kansas, Louisiana, and the
remaining States it is obtained both from brines and by mining as
rock salt.
Of the foreign sources of rock salt the following districts are the
most important: (i) The Carpathian Mountains, (a) the Austrian
and Bavarian Alps, (3) Western Germany, (4) the Vosges, {5) Jura,
(6) Spain, (7) the Pyrenees and the Celtiberian Mountains, and
(8) Great Britain, while sea salt is an important product of Turks
Island in the Bahamas, of the island of Sicily, and of Cadiz, Spain.
Space can here be devoted to details concerning but a few of diese
localities, preference naturaUy being given to those of the United States.
The beds of New York State, of Ontario, northern Pennsylvania,
northeastern Ohio, and eastern Michigan all belong to the same
geologic group — are the product of similar agencies. They have
been penetrated in many places by wells, and from the results ob-
tained one is enabled to form some idea of their extent and thickness.
Below is given a summary of results obtained in boring a well to
a depth of 1,517 feet at Goderich, Canada. Beginnmg at the sur-
face, the rocks were passed through in the following order:
Pt. In.
I. Clay, gravel, marls, limestone, dolomite, and gypsum variously
inteislratificd i 997 o
a. First bed of rock salt 30 11
3. Dolomite with marls 31 i
4. Second bed of rock salt »S 4
S- Dolomite 6 10
6. Third bed of rock salt 34 10
7. Marl, dolomite, and anhydrite So 7
8. Fouith bed of rock salt 15 5
9. Dolomite and anhydrite. 7 o
10. Fifth bed of rock salt 13 6
11. Mari and anhydrite 135 6
I J. Sixth bed of rock salt 6 o
13. Marl, dolomite, and anhydrite 133 o
Total thickness of formations passed throu^ 1,517 feet-
Total thickness of beds of salt 116 feet
The sectbn shows that the ancient sea or lagoon underwent
at least six successive periods of desiccation, and especial attention
is called to the remarkable r^ularity of the deposits. On the
oklest sea bottom (13) the carbonates and sulphates of lime and
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48 THE NON-METMLUC MINERALS.
magnesia were deposited first, being least soluble. Then followed
the salt, and this order is repeated invariably. The other con-
stituents mentioned as occurring in the waters of lakes and seas
are not sufficiently abundant to show in the section, or owing to
their ready solubility have been in large part removed since the
beds were laid down. Chemical tests, however, reveal their presence
in small but varying quantities.
Although salt was manufactured from the brine of springs, near
Onondaga Lake, in New York, as early as 1788, and has been regu-
larly manufactured from the brine of wells since 1798, it was not
until subsequent to the discovery of extensive beds of rock salt in the
Wyoming Valley, while boring for petroleum, that the mining of
the material in this form became an established industry. In June,
1878, a bed of rock-salt 70 feet in thickness was found in the valley
above mentioned, at a depth of 1,270 feet. Subsequently other
borings in Wyoming, Genesee, and Livingston counties disclosed
beds at varying depths. In 1885 the first shaft was sunk at Pifford
by the Retsof Mining Company, the salt bed being found at a depth
of 1,018 feet. Other shafts have since been sunk, the first about
a mile west of the Retsof, the second about 2 mQes south of Leroy,
and the third at Livonia, in Livingston County. The salt wh«i
taken from the bed is of a gray color, due to the presence of clay,
which renders solution and recrystallization necessary when de-
signed for culinary purposes. The thickness of the beds and their
depth are somewhat variable. The following figures are quoted
from Dr. Engelhardt's report.^ At MorrisviUe, in Madison County,
it is li'feet thick and at a depth of 1,259 feet; at Tully, in Onon-
daga County, it varies from 25 to 318 feet, at depths of from 974
to 1,465 feet. The seven beds found at Ithaca have a total thickness
of 248 feet, the uppermost lying at a depth of 2,244 ^eet. In the
Genesee Valley the beds vary in depth from 750 to 2,100 feet, and
in thickness from 40 to 93 feet. In the Wyoming Valley the depth
varies from 610 to 2,370 feet below the smiace, and in thickness
from 12 to 85 feet.''
' The Mineral Industry, ils Statislics and Trade for 1891, by R. P. Roihwell.
' For a very complete historical and geological account of these salt beds and the
method of manufacture, see Bulletin No. 11, of Ibe New York State Museum, 1SQ3,
by F. J. H. Merrill.
o,Got>^lc
HALIDES. 49
Ohio. — The first attempts at salt making in this State was made
in 1798 with brines from salt springs in Jackson County. These,
which became known as the Scioto Valley Works, were abandoned
about 1818 owing to the discovery of richer brines in the Kanawha
Valley and elsewhere. Drilling for salt began in the Muskingum
Valley near Zanesville in 1817, and by 1833 the output of this val-
ley alone amounted to 300,000 or 400,000 bushels annually. At
the present date (1909) the principal works are in Meigs, Morgan,
Franklin, Wayne, Medina, and Summit counties. During the years
immediately following the Civil W^ there were thirteen furnaces
in the State for the evaporatk>n of brines. The number has gradually
declined to five, owing to the cheaper production from wells in
Michigan and New York. The densest of the Ohio brines come
from the Berea Grits, but the amount is small; the so-called Big
Salt Sand is the most prolific source. The wells vary in depth
from i,coo to 3,000 feet.*
Michigan. — The salt-producii^ areas of this State are, so far
as now known, limited to the counties of Iosco, Bay, Midland,
Gratiot, Saginaw, Huron, St. Clair, Manistee, and Mason, the beds
of the Saginaw Valley lying in the so-called Napoleon sandstone,
at the base of the Carboniferous. Professor Winchell has estimated
this formation to cover an area of some 17,000 square miles within
the State limits- The beds of the St. Clair Valley, on the other
hand, are in upper Silurian strata, being presumably continuous
with those of Canada. The manufacture of salt from brines pro-
cured from these beds began in the Saginaw Valley in i860, and
has since extended to the other regions mentioned. According to
F. E. Engelhardt the rock-salt deposits in the Upper Silurian beds,
with a thickness of 115 feet, were reached at Marine City, in St.
Clair County, at a depth of 1,633 ^'^^^'' ^.t St. Clair, St. Clair County,
at a depth of 1,635 ^^^^1 ^^^ ^'^^ ^ thickness of 35 feet. At Caseville,
in Huron County, the beds lie at a depth of 1,164 f^t> "nd at Bay
City, Saginaw Bay, at 2,085 f^^t. the salt beds being 115 feet in
thickness. At Manistee the bed is 34 feet thick, lying 2,000 feet
below the surface, while at Muskegon, in the Mason well, it was
50 feet thick at a depth of 3,200 feet.
' Bulktia No. S, Geological Surve]' of Ohio, 1906.
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5° THE NON-METALUC MINERALS.
Kansas.— la this State the rock salt occurs in beds regarded as of
Permian age, and has been reached by means of shafts in several
counties in the southern and central part of the State. The following
is a section of a shaft sunk in Kingman in 1888-89:
Fe«t.
"Red-beds," red arenaceous, limestones, ferruginous clays, and clay shales
with thin strealu of gray shales and bands of gypsuni as satin spar 450
Gray or bluish "stale," with 1 feet of limestone at 500 feet 140
Red clay shale 4
Gray "slate," with occasional streaks of limestone, a to 8 inches Ihictc, and some
salt partings and satin spar with ferruginous stain 78
Fiist rock salt, pure white >
Shale and "slate," bluish, with vertical and other seams of salt, from i to 3
inches thick 36
Rock salt 4
Shales, with salt II
Rock salt 7
Shale 3
Rock sail 3
Salt and shale, alternate thin seams 61
Rock salt II
Shale iiV
Rock salt 5
Shales and limestone S
Rock sail, bottom of it not reached 5
Total 810
Borings and shafts have also proven the existence of beds of salt
in other parts of the State, as at Kanopolis, Lyons, Caldwell, Rago,
Pratt, and Wilson. According to Dr. Robert Hays' it is safe to
assume that beds of rock salt from go to 1 50 feet in thickness under-
lie fully half the area from the south line of the State to north of
the Smoky River, an area from 20 to 50 miles in width. Although
the mining of rock salt began in this region only in 1888, the annual
output has already reached over 1,000,000 barrels.
Louisiana. — Salt in this State is derived from Petite Ange, a
small island rising from the marshes on the southern coast and con-
nected with the mainland by a causeway some 2 miles in length.
According to E. W. Hilgard* the deposit is probably of Cretaceous
Age, and presumably but a comparatively small residual mass
' Geological and Mineral Resnirces of Kansas, 1893, p. 44.
' Smithsonian Contributions to Knowledge, XXIII. On the Geology ot Lowei
Louisiana and the Salt Deposit on Petite Anse I^nd.
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of beds once extaiding over a much larger area, but now lost through
erosion. (See F^. lo.) G. D. Harris,' however, regards them as
deposits from springs ascending from deep-seated sources along lines
of faults, the dome-shaped structure being due to the gradual
Fio. 9. — Map of Petite Anse, Louisiana.
{After Hilgard.]
forcing up of the deposit first formed by the crystallization of new
material brought up by hydrostatic pressure from beneath.
Kentucky. — Salt in Kentucky is obtained from the brine of
springs and wells in Carboniferous limestone. In Meade County
brine accompanies the natural gas, the latter in some cases being
' Economic Geobgist, IV, No. 1, 1909.
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THE NON-METALUC MINERALS.
utilized as fuel for
its evaporation.
Springs in Webster
County furnished
salt for Indians long
anterior to theoccu-
pancy of the county
by whites, and frag-
ments of their clay
kettles and other
utensils used in the
work of evapora-
tion are stiU occa-
sbnally found.
Texas, — The oc-
currences of salt are
numerous and wide-
spread. Along the
coast are many la-
goons and salt lakes,
from which con-
siderable quantities
are taken annually.
"Besides the lakes
along the shores
many others occur
through western
Texas, reaching to
the New Mexico
line, while northeast
of these, in the Per-
mian regk>n, the
constant recurrence
of such names as
Salt Fork, Salt
Creek, etc., tell of
the prevalence of
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MAUDES. 53
similar conditions." In addition to the brines there are extensive
beds of rock salt. That which is at present best developed b
located in the vicinity of Colorado City, in Mitchell County, The
bed was found at a depth of 850 feet, with a thickness of 140 feet.
At the " Grand Saline" in Van Zandt County, a bed of rock salt
over 300 feet in thickness was found at a depth of 225 feet.
England. — In England the salt occurs at Cheshire in two beds
interstratified with marls and clays. The upper, with a thickness
varying from 80 to go feet, lies at a depth of some 120 feet below
the surface, and the second at a depth of 226 feet has a thickness
varying between 96 and 117 feet. The accompanying general
sections are from Davies' Earthy and other Economic Minerals.
AT wirrON, Ni
TO THE LOWER BED OF SALT.
Fl. Ii
I. Calcareous mar] 15
1. Indurated red clay 4
3. Indurated blue clay and marl 7
4. Argillaceous marl r
5. Indurated blue day I
6. Red day with sulphate of lime in irregular brandies 4
7. Indurated red day with grains of sulphate of lime interspersed 4
8. Indurated brown clay with sulphate of lime crystallized in irregular masses
and in large proportions 12
g. Indurated blue clay with lamina of sulphate of Ume 4
10, Argillaceous marl 4
11. Indurated brown ciay laminated with sulphate of lime 3
11. Indurated blue clay laminated with sulphate of lime 3
13. Indurated red and blue day 13
14. Indurated brown clay with sand and sulphate of lime irregularly inter-
spersed through it. The fresh water, at the rate of 360 gallons a
minute, forced its way through this stratum 13
15. Argillaceous marl 5
16. Indurated blue day with sand and grains of sulphate of Ume 3
17. Indurated brown clay as next above 15
18. Blue day as strata next above i
19. Brown day as strata next above 7
ao. The top bed of rock salt 75
ai. Layers of indurated clay with veins of rock salt running through them 31
31. Lower bed of rock salt 115
Total 341
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54 THE NON-METALLIC MINERALS.
Poland. — At Wieliczka, in Austrian Poland, the salt occurs in
massive beds stated to extend over an area some 20 by 500 miles, with
a maximum thickness of 1,200 feet. At Parajd, in Transylvania,
beds belonging to the same geological horizon are estimated to
contain upward of 10,000,000,000,000 cubic feet of salt.
Fic. II. — Cluster of sylvitc crystals, showing chatacleristic cubo^jctahedral forms.
Slassfurt, Germany.
[U. S. National Museum,]
Cermany. — One of the most remarkable deposits of the world,
remarkable for its extent as well as for the variety of its products, is
that of Stassfurt, in Prussian Saxony. On account of its unique char-
acter, as well as its commercial importance, being to-day the chief
source of natural potash salts of the world, a little space may well be
given here to a detailed description.'
' Jourinl of the Sue iciy of Chemical Induslry, II, iS8i, i)|i. J46, 147.
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HAUDES. SS
Stassfurt is about 25 nules southwest of the city and fortress of
M^deburg, in Prussia. It lies in a plain intersected by the river
Bode, which takes its rise in the Harz Mountains. The salt industry
here is a very old one, dating back as far as the year 806. Previous
to 1839 the salt was produced from brine pumped from wells sunk
about 200 feet into the rock. The brine, in the course of time,
became so weak that it was impossible to carry on the manufacture
without loss. In 1839 the Prussian Government commenced bor-
ing with the object of discovering the whereabouts of the bed of rock
salt from which the brine had been obtained. In 1843, seven years
after the commencement of the borings, the top of the rock salt was
reached at a depth of 356 meters. The boring was continued through
another 325 meters into the rock salt without reaching the bottom
of the layer. At this total depth of 581 meters the boring was sus-
pended. On analyzing the brine obtained from the bore-bole, it
was found to consist, in 100 parts by weight, of —
Sulphate of calcium 4.01
Chloride of potassium 2.24
Chloride of magnesium ^9-43
Chloride of sodium 5.61
This result was not only imexpected, but disappointing, since the
presence of chloride of magnesium in such quantities dispelled for
the time all hopes of striking pure rock salt. The Government,
however, guided by the opinions expressed by Dr. Karsten and
Professor Marchand, to the effect that the presence of chloride of
m^nesium in such quantities was probably due to a depxisit lying
above the rock salt, determined to further investigate the matter,
and in the year 1852 the first shaft was commenced, which after five
years had penetrated, at a depth of 330 meters, into a bed of rock salt,
passing on its way, at a depth of 256 meters, a bed of potash and
magnesia salts of a thickness of 25 meters.
On referring to the section of the mines (Plate II) it will be seen
that the lowest deposit of all consists of rock salt. The bore-hole
was driven 381 meters into it without reaching the bottom of the
layer. Its depth is therefore unknown. The black lines drawn
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so THE NON-METALUC MINERALS.
throu^ the rock-salt deposit represent thin layers of anhydrite
7 miUimeters thick, and almost equidbtant. The lines at the top
of the rock salt represent thin layers of PolyhaUile, the trisulphate
of potash, magnesia, and lime. The deposit lying immediately
on the bed of rock salt consists chiefly of the mineral Kieserile, a
sulphate of magnesia. Still farther toward the surface the deposit
consbts of the double chloride of potassium and magnesium, known
as CamaUUe, mixed with sulphate of magnesia and rock salt. The
deposit to the right, on the rise of the strata, consists of the double
sulphate of potash and magnesia combined with one equivalent of
chloride of magnesium, and intermingled with common salt to the
extent of 40 per cent. The double sulphate is known as Kainite
and is a secondary formation, resulting from the action of a limited
quantity of water on a mixture of sulphate of magnesia and the
double chloride of potassium and magnesium, as contained in the
uppermost deposit previously spoken of.
Sixteen different minerab have been di^overed in the Stassfurt
deposits. They may be divided into primary and secondary for-
mations. Those of primary formation are rock salt. Anhydrite,
Polyhailite (K3SO4, MgSO*. 2CaS04, 2H3O) Kieserite {MgSOi,
H2O), CamallJte (KCl,MgCla, 6H2O), Boracite (2(Mg3B80i6),
MgCla), and Douglasite (2KCl,FeCl3, 2HaO). Those of secondary
formation, resulting from the decomposition of the primary minerals
are nine in number, namely : Kainite (KaSO^, MgS04, MgCl26H20);
Sylvite (KCl); Tachydrite (CaCla, 2 MgCl2 + i2HzO); Bischofite
(MgCla, 6H2O); Krugite (K2SO4, MgSO*, 4CaS04, 2H2O); Reich-
ardtite (MgSO*, 7H2O); Glauberite {CaS04, NaaSOO; Schonite
(KaSO*, MgS04, 6HaO}, and Astrakanite (MgSO*, 4H2O). Only
four of these nuncraJs have any commercial value, namely: CamaUite,
Kainite, Kieserite, and rock salt. The jaeld of boracite, which is
found in nests in the CamaUite region of the mine, is too insignifi-
cant to be classed among those just mentioned.
In certains parts of the CamaUite region, the rock salt is found
crystaUized in the form of the cube and the octahedron, sometimes
colored different shades of red and blue.
Methods of mining and manufacture.- In the manufacture of
salt three principal methods are employed. The first, if, indeed, it
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Prussian Shafts.
Secfion o( Salt Bedsal Stassfurt, Germany. (-~- -, -, -,|^
(Trans. Edinburgh Geological Society. Vol. V, 1884.] ^lOOglC
[Facing page $6.]
J, Google
HALIDES- 57
can be called manufacture, consists in mining the diy salt from an
open quarry, as in the Rio Virgen and Barcelona deposits, or by
means of subterranean galleries, the methods employed at Petite
Anse and in Galacia.
At Petite Anse the method of mining and preparation, as given
by Mr. R. A. Pomeroy,' is as follows:
Mining is done by means of galleries on two levels. There are
i6 to 25 feet of earth above the salt deposit. The contour of the
latter conforms nearly with that of the surface- The working shaft
b 168 feet deep. The depth of the first level of floor is ga feet; to
the second, 70 feet farther. The remaining 8 feet are used for a
dump. The galleries of the first level were run, on an averse, 40
feet in width and 25 feet and upwards in height, leaving supporting
pillars 40 feet in diameter.
The galleries of the second level are run 80 feet in width and
45 feet in height, leaving supportii^ pillars 60 feet in diameter.
The lower pillars are so left that the weight of the upper ones rests
upon them in part, if not wholly, with a thickness of at least 25 feet
of salt rock between. Galleries aggregating nearly i mile in length
have beai run on the upper level and some 700 feet on the
lower.
The salt as it comes from the mine is dumped into corrugated
cast-iron rolls, which crush it. Next it goes into revolving screens,
which take out the coarser lumps for "crushed salt" and let the
fine stuff pass to the buhrstones. These grind the salt, and from
them it goes to the pneumatic separators, which take out the dust
and separate the market salt into various grades. Taking the dust
out is essential to the production of a salt that will not harden, since
the fine particles of dust deliquesce readily, and on drying cement
the coarse particles together.
On the Colorado Desert the salt occurs in the form of a crust a
foot or more in thickness, resting on a shallow lake of brine. This
crust, which is covered with a thin layer of dust and sand blown
over it from the surrounding desert, is cut away longitudinally, much
■ TtansBctioiis of the AmerlaD Institute Mining Engineen, XVII, 1SS8, 18S9,
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58 THE NON-METALLIC MINERALS.
as ice is cut in the North. When loosened, the block, falling into
the water beneath, is cleaned of its impurities, and is then thrown
out on a platform to diy, after which it is ground and packed for
market. In many parts of the arid West the salt is obtained merely
by shoveling up the impure material deposited by the evaporation
of salt lakes and marshes during seasons of drought. In this way
is obtained a large share of the material used in chloridizing ores.
In the preparation of salt from sea water, solar evaporation alone
is relied upon nearly alt(^ether. This method, like the next to be
mentioned, depends for its efficiency upon the fact already noted
— that sea water holds in solution besides salt various other ingre-
dients, which, owing to their varying degrees of solubility, are depos-
ited at different stages of the concentration. In Barnstable County,
Massachusetts, it was as follows: A series of wooden vats or tanks,
with nearly vertical sides and about a foot in depth, is made from
planks. These are set upon posts at different levels above the
ground, and so arranged that the brine can be drawn from one
to another by means of pipe^. Into the first and highest of these
tanks, known as the "long water room," the water was pumped di-
rectly from the bay or artihcial pond by means of windmills, and there
allowed to stand for a period of about ten days, or until all the sed-
iment it may carry was deposited. Thence it was run through pipes
to the second tank, or " short water room," where it remained exposed
to evaporatbn for two or three days longer, when it was drawn off
into the third vat, or "pickle room," where it stood until concen-
tration had gone so far that the lime was deposited and a thin pellicle
of salt began to form on the surface. It was then nm into the fourth
and last vat, where the final evaporation took place and the salt itself
crystallized out Care was requisite, however, lest the evapora-
tion proceed too far, in which case sulphate of soda (Glauber's salt)
and other mjurious substances could also be deposited, and the quality
of the sodium chloride thereby be greatly deterbrated.
As to the capabilities of works constructed as above, it may be
sakl that during a dry season vats covering an area of 3,000 square
feet would evaporate about 32,500 gallons of water, thus producing
some 100 busheb of salt and 400 pounds of Glauber's salt. The
moist climate of the Atlantic States, however, necessitates the roof-
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HAUDES. 59
ing of the vats in such a manner that they can be protected or exposed
as desired, thereby greatly increasing the cost of the plant. Sundry
parts of the Pacific coast, on the other hand, owing to thtir almost
entire freedom from rains during a large part of the year, are pecu-
liarly adapted for the manufacture by solar evaporation. Hence,
while the works on the Atlantic coast have nearly all been discon-
tinued, there has been a corresponding growth in the West, and
particularly in the region about San Francisco Bay.
The methods of procedure in the CaUfomia works do not differ
materially from that already given, excepting that no roofs are
required over the vats, which are therefore made much larger. One
of the principal establishments in Alameda County may be described
as follows : The works are situated upon a low marsh, naturally cov-
ered by high tides. This has been divided, by means of piles driven
into the mud and by earth embankments, into a series of seven vats
or reservoirs, all but the last of which are upon the natural surface
of the ground — that is, without wooden or other artificial bottoms.
The entire area inclosed in the seven vats is about 600 acres, neces-
sitating some 15 miles of levfes. The season of manufacture lasts
from May to October. At the beginning of the spring tides, which
rise some 12 to 15 inches above the marsh level, the fifteen gates of
reservoir No. i, comprising some 300 acres, are opened and the
waters of the bay allowed to flow in. In this great artificial salt lake
the water is allowed to stand until all the mud and filth have become
precipitated, which usually requires some two weeks. Then, by
means of pumps driven by windmills, the water is driven from
reservoir to reservoir as concentration continues, till finally the salt
crystallizes out in No. 7, and the bittern is pumped back into the
bay. The annual product of the works above described is about
3,000 tons.
A somewhat similar process is pursued in the manufacture of salt
from inland lakes, as the Great Salt Lake, Utah.
The water is pumped from the lake into ponds prepared for
its reception and situated above the level of the lake surface.
In the first pond the mechanically suspended matters are left as
sediment or scum, and the water passes into the second in a clear
condition. The ponds cover upward of a thousand acres, and the
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6o THE NON-METALLIC MINERALS.
drain channels leading from them aggregate 9 miles in length.
The pumping continues through May, June, and July. A fair idea
of th : rate of evaporation in the thirsty atmosphere of the Great Basin
may be gained from contemplating the fact that to supply the volume
of water disappearing from the ponds by evaporation requires the
action of the pumps -lo hours daily in Jime and July. This is equal
to the carrying away of 8,400,000 gallons per day from the surface
of the ponds.
"The 'salt harvest' begins in August, soon after the cessation
of pumping, and continues till all is gathered, frequently extending
into the spring months of the succeeding year. An average season
yields a layer of salt 7 inches deep, which amount would be deposited
from 49 inches of lake water. The density at which salt begms to
deposit, as observed at the ponds and confirmed by laboratory
experiments, is 1.2121, and that of the escaping mother liquors is
1.2345. The yield of salt is at the rate of 150 tons per inch per
acre.1
Owing to the depth below the surface of the salt beds in Ohio,
Michigan, and other inland States, the matetiat is never mined as
in the cases first mentioned, but is pumped to the surface as a brine
and there evaporated by artificial heat. In the Warsaw Valley region
the beds lie from 800 to 2,500 feet below the surface, and are reached
by wells. These are bored from 5J to 8 inches in diameter and are
cased with iron pipes down to the salt. Inside the first pipe is then
introduced a second 2 inches in diameter, with perforations for a
few feet at its lower end, and which extends nearly, if not quite, to
the bottom. Fresh water is then allowed to run from the surface
down between the two pipes. Thb dissolves the salt, and forms a
strong brine which, being heavier, sinks to the bottom of the well
and b pumped up through the smaller or inner tube. At Syracuse
the wells are not sunk into the salt bed itself, but into an ancient
gravel deposit which is saturated with the brine. Here the intro-
duction of water from the surface is done away with. Irt those
cases, not at all uncommon, where the brine flows naturally to the
surface in the form of a spring, pumping is of course dispensed with.
' J. E. Tatmagc Science, XIV, 1889, p. 443,
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The methods of evaporation vary somewhat in detail. In New
York the brine is ran in a continuous stream in large pans some 130
feet long by 20 feet wide and 18 inches deep. As it evaporates the
salt is deposited on the bottom, and, by means of long-handled
scrapers, is drawn on the sloping sides of the pan. Here it is allowed
to drain, and is afterwards taken to the storage bins for packing or
grinding,' Salt thus produced, it should be noticed, is never so
coarse as the so-called rock salt, or that which has formed by natural
evaporation. In Michigan the brine from the wells is first stored
in cisterns, whence it is drawn off into large shallow pans, known
technically as "settle;^," where it is heated by means of steam pipes
to a temperature oi iTS", until the point of saturation b reached.
It is then drawn into a second series of pans, called "grainers,"
where it is heated to a temperature of 185°, until crystallization
takes place.
The strength of brines, and therefore the quantity of water that
must be evaporated to produce a given quantity of salt, varies
greatly in different localities. At Syracuse the brine contains 15.35
per cent of salt; at the Saginaw Valley, 17.91 per cent; at Saltville,
Virginia, 25.97 P^r <^™t; while Salt Lake contains 11,86 per cait,
and the waters of San Francisco Bay but 2,37 per cent The amount
of impurities in the final product depends on the care exercised in
process of manufacture, rapid boiling giving less satisfactory results
than slower methods. The Syracuse salt has been found to contain
98.5a per cent sodium chloride; California Bay salt 98.43 per cent
and 99.44 per cent; and Petite Anse 99.88 per cent The impurities
in these cases are nearly altogether chlorides and sulphates of lime
and magnesia.
In many works, and particularly those of Michigan and Ohio,
bromine is distilled and condensed from the bittern left from the
crystallization of the salt. It is stated ' that in some of the Ohio
works the liquid remaining from the dbtillation of the bromine is
run into a cistern and treated with lime. This neutralizes any add
' For details, see Salt and Gypsum Industries ol New Yoik, by Dr. F. J. H. Mer-
rill, Bulletin No. 11, New York St«e Museum, 1893.
* Bulletin No. 8, Geological Survey of Ohio, 1906.
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6a THE NON-METALLIC MINERALS.
remaining from the bromine process. The liquid is then con-
densed by boiling in open pans, until calcium chloride separates
out.
The Cheshire (En^and) salt beds are worked both by mining
as rock salt and by pumping the brine. Formerly both upper and
lower beds were mined, but flooding and falling in of the roofs
caused the work to be discontinued on the upper beds. That now
mined as rock salt comes wholly from the lower bed, and being
impure is used mainly for agricultural purposes.
At Wieliczka the salt is likewise mined from galleries resembling
in a general way those of a coal mine. These, according to Brehm,'
begin at a depth of about 95 meters, forming several levels connected
by stairways, the lowermost gallery being at a depth of 312 meters,
or some 50 meters below sea level. These galleries have a total
length of some 680 kilometers. They are connected with one
another by means of eleven pits of which seven are utilized for
hoisting purposes. The work goes on continually night and day
the year through. The salt is cut out in the form of blocks, leaving
huge chambers, the roof being sustained by means of large columns
of salt left standing. The temperature within these chambers is
very uniform, varying only between 10° and 15" C. The air is dry
and healthful. The miners hew out of the salt statues of the saints,
pyramids, and chandeliers. One chamber, called the Chapel of
St. Antoine, with its altar, statues, columns, etc., is still in a condi-
tk>n of perfect preservation after a lapse of two centuries.
The output of salt in the United States for 1900 amounted to
upwards of 20,000,000 barrels of 280 pounds each, of which 85 per
cent was from mines and wells in New York, Michigan, and Kansas.
For 1907 the output was 29,704,128 barrels, valued at $7,439,537.
The annual output for the entire world amounts to upwards of
10,000,000 metric tons.
Uses. — ^The principal uses of salt have always beai for culinary
and preservative purposes. Aside from these, it is also used in
certain metallurgical processes and in chemical manufacture, as in
the preparation of the so-called soda ash (sodium carbonate), used
• MEirveilles de la Nature. La Terre, etc., p. 315.
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H^UDHS. , 63
in glass making, soap making, bleachii^, etc., and in the preparation
of sodium salts in general Clear, transparent salt has been utilized
in a few instances in optical and other research work.
2. FLUORITE.
This is a calcium fluoride, CaF„ = fluorine, 48.9 per cent ; calcium,
51. 1 per cent. The most striking features of the mineral are its
cubic crystallization, octahedral cleavage, and fine green, yellow,
purple, violet, and sky-blue colors. White and red-brown varieties
are also known. The mineral is translucent to transparent, and
of a hardness somewhat greater than calcite (4 of Dana's scale).
Occurrence. — The mineral occurs, as a rule, in veins, in gneiss,
the schists, limestones, and sandstones. It is also a common gangue
of metallic ores, panicularly those of lead and tin.
The principal American sources are Rosiclare, in southern Illi-
nois, and on the opposite side of the Ohio River, in Kentucky, though
deposits have been reported in Smith, Trousdale, and Wilson coun-
ties in Tennessee, and near Yuma, Arizona,
At Rosiclare the fluorspar occurs in what are regarded as true
fissure veins varying from 4 to 40 or more feet in width in the
Lower Carboniferous limestone. The original veins were, however,
much smaller, the crevices having been enlarged by circulating
waters, and the present great width being due to a partial replace-
ment of the limestone.
On the hanging-wall side of the veins the fluorspar contents are
not pure, and often contain fragments of the country rock. There
is also no sharp contact of the vein with the wall. Near the foot-
wall the fluorspar is often found in solid masses from 2 to 12 feet
in thickness. With the fluorspar there is nearly always associated
calcspar, galena, and sphalerite, and occasionally pyrite, chalcopy-
rite, and barite.
The depth to which the deposits extend has not been determined,
but they have been worked to a depth of 200 feet without any appar-
ent diminution in width of the vein, and Emmons regards it as
reasonable to assume that they will extend as far down as the Trenton
and Cambrian limestone.
At the Riley mine, in Crittenden County, Kentucky, the fluorite
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THE NON-METALLIC MINERALS.
occurs as a vein filling a fault fissure between the St. Louis (sub-
Carboniferous) limestone on the southeast, and the BirdsviUe quartz-
ite on the northwest. The vein is some 3 to 4i feet in width,
striking N, 44° E, The south-
eastern wall, so far as exposed,
consists of red residual clay and
chert, with scattered blocks of the
limestone. Toward the bottom
of the shaft — some 75 feet, as
shown in Fig. 12 — is a strip of
shale about 3 feet in thickness,
apparently dragged in along the
fault plane. The vein filling mat-
ter is mainly fluorite, with some
white calcite and barite. Banding,
parallel with the walls, is sometimes
appaxeot The fiuorite of both
Illinob and Kentucky is regarded
as deposited from solutbns, the
material being originally a minor
constituent of the deeper-lying
limestone, whence it was leached
by ascending thermal waters, the
activity of which was excited by
the intrusions of the neighboring
peridotites.
In both States the deposits are
worked by means of shafts and
drifts. As taken from the mine,
mineral is, In some cases,
concentrated by a handcobbing
machine and by the use of water-
jigs, though in some cases it is shipped directly from the mine
after havmg been simply washed. In a number of cases the
lead and zinc ores commingled with the fluorite are saved as by-
products.
Fig. 12. — Section of fluorite vein,
Chittenden County, Kentucky'.
[After W. S. I. Smith, Prof. Paper U.
S. Geokigic&l Survey, No. 36.]
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MAUDES. 65
lUinois and Kentucky are the principal sources of fluorspar as
at present mined in America. The actual amount there existing
is probably more than sufficient to supply the demand for many
years to come. The average output at date of writing is between
40,000 and 50,000 tons, valued at from $5 to $10 per ton, according
to quality.
Uses. — The material is used mainly as a flux for iron, in the
manufacture of opalescent glass, and for the production of hydro-
fluoric acid.
BIBUOGRAPHY.
S. F. ElluoNS. Fluorspar Deposits of Southern Illinois.
Transadioiis of the American Institute of Mining Engineers, XXI, 1893, pp.
31-53-
H. F. Bain. Fluorspar Deposits of Southern Illinois.
U. S. Geological Survey, Bulletin No, 155, 1905.
W. S. I. SuiTH. Lead, Zinc, and Fluorspar Deposits of Western Kentucky.
U. S. Geological Survey, Prof. Paper No. 36, 1905, pp. 107-307,
3. CRYOLITE.
Composition. — Na^AlF,, —aluminum, 12.8 percent; sodium, 32.8
per cent; fluorine, 54.4 pwr cent. The mineral is, as a rule, of snow-
white color, though sometimes reddish or brownish, rarely black,
and coarsely crystalline granular, translucent to subtransparent. It
has a hardness of 2.5; specific gravity of 2.9 to 3, and in thin splinters
may be melted in the flame of a candle.
The name is from the Greek word Kpvos, ice, in allusion to
its translucency and ice-like appearance.
Mode of occurrence. — Cryolite occurs, as a secondary product,
in. the form of veius. It is rarely found in sufficient abundance to
be of commercial value, the supply at present coming almost wholly
from Evigtok in South Greenland. The country rock here is said
to be granite, and the vein as described in 1866 • was 150 feet in
' Paul Quale, Report of Smithsonian Institution, iS66, p, 398.
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66 THE NON-METALLIC MINEKALS.
greatest breadth, and was exposed for a distance of 600 feet The
principal mineral of the vein was cryolite, but quartz, siderite, galena,
and chalcopyrite were constant accompaniments, irregularly dis- ■
tributed through the mass. In 1890 the mine as worked was de-
scribed as elliptical in shape, 450 feet long by 150 feet wide, the pit
being some 100 feet deep. The drills had penetrated 150 feet deeper
and found cryolite all the way. Johnstnip, as quoted by Dana,*
describes the cryolite as "limited to the granite; he distinguishes a
central and a peripheral part; the former has an extent of 500 feet
in length and 1,000 feet in breadth, and consbts of cryolite chiefly,
with quartz, siderite, galena, sphalerite, pyrite, chalcopyrite, and
wolframite irregularly scattered through it. The peripheral por-
tion forms a zone about the central mass of cryolite; the chief min-
erals are quartz, feldspar, and ivigtite, also fluorite, cassiterite,
molybdenite, arsenopyrite, columbite. Its inner limit is rather
sharply defined, though there intervenes a breccia-like portion con-
sisting of the minerals of the outer zone inclosed in cryolite; be-
yond this it passes into the surrounding granite without distinct
boundary."
Cryolite in limited quantity occurs at the southern base of Pike's
Peak, in Colorado, and north and west of St. Peter's Dome. It is
found in vein-like masses of quartz and microdine embedded in
granite.
Uses. — The material has been utilized in the manufacture of
soda, and sodium and aluminum salts, and to a small extent in the
manufacture of glass and procelain ware. It is also used in the
electrolytic processes of extracting aluminum from its ores, as now
practiced.
The principal works utilizing the Greenland cryolite in chemical
manufacture are, at time of writing, those of the Pennsylvania Salt
Manufacturing Company at Natrona, Pennsylvania. From 5,000
to 10,000 tons are imported annually, valued at about $iz
per ton,
' System of Minemlogy, i8ga, p. 167.
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IV. OXIDES.
Quartz. — ^The mineral quartz, easily recognized by its insolu-
bility in acids, glassy appearance, lack of cleavage, and hardness,
which is such that it readily scratches glass, is one of the most common
and widely disseminated of minerals. Chemically it is pure silica,
of the formula SiOj. It crystallizes in the hexagonal system with
pyramidal terminations, and is one of the most attractive of minerals
for the amateur collector. The conunon form is, however, massive,
occurring in veins in the older crystalline locks. Common sand
is usually composed mainly of quartzose grains which, owing to
their hardness and resistance to atmospheric chemical agencies,
have withstood disintegration to the very last.
The terms rose, milky, and smoky are applied to quartzes which
differ from the ordinary type only in tint, as indicated. Chalcedony is
the name given to a somewhat hom-like, translucent or transparent
fonn of silica occurring only as a secondary constituent in veins, or
isolated concretionary masses, and in cavities in other rocks. Agate
is a banded variety of chalcedony. The true onyx is similar to
agate, except that the bands or layers of different colors lie in even
planes. Jasper is a ferruginous, opaque chalcedony, sometimes used
for ornamental purposes. Opal is an amorphous form of silica,
containing somewhat variable amounts of water.
Quartz occurs as an essential constituent of granite, gneiss,
mica schist, quartz porphyry, and liparite, and also as a secondary
constituent in the form of veins, filling joints and cavities in rocks of
all kinds and all ages.
Uses. — The finer clear grades of quartz were formerly used to
some extent for spectacle lenses and optical work. Its main value
is for abrading purposes, either as quartz sand or as sandpaper,
and in the manufacture of pottery. For abrading purposes it is
crushed and bolted, like emery and corundum, and brings a price
barely sufficient to cover cost of handling and transportation. There
is a remarkable variation in quartz as relates to its suitability for
abrasive purposes, some varieties on crushing giving rise to sharp,
splintery fragments possessing a h^ degree of cutting or abrading
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68 THE NON-METALUC MINERALS.
power, while others yield sands that are dull and of less value. As
a rule the clear, glassy quartz will yield a sharper sand than the
opaque and milky forms.
Ground quartz is used to some extent as a "filler" in paints, and
as a scouring material in soaps. (See further under Sand for glass
making, p. 419).
Flint is a chalccdonic variety of silica found in irregular nodular
forms in beds of Cretaceous chalk. These nodules break with a
conchoidal fracture and interiorly are brownish to black in color.
By the aboriginal races the flints were utilized for the manufacture of
knives and general cutting implements. Later they were used in ihe
manufacture of gun-flints and the "flint and steel" for producing
fire. At present they are used to some extent in the manufacture of
porcelain, being calcined and ground to mix with the clay and give
body to the ware. In this country the same purpose is accomplished
by the use of quartz. Small round nodules of flint from Dieppe,
France, are said to be used in the Trenton (New Jersey) pottery
works for grinding clay by being placed in revolving vats of water
and kaolin. All the flint now used in this country is imported either
as ballast or as an accidental constituent of chalk.
As the material is worth but from $1 to $2 a ton delivered at
Trenton, it may be readily understood that transportation is a rather
serious item to be considered in developing home resources.
According to Mr, R. T. Hill, nodules of black flint occur in enor-
mous quantities in the chalky limestones — the Caprina Hmestones —
of Texas. Numerous localities are mentioned, the most accessible
being near Austin, on the banks of the Colorado River.
Buhrstone, or burrstone, is the name given to a variety of
chalcedonic silica, quite cavernous, and of a white to gray or slightly
yellowish color. The cavernous structure is frequently due to the
dissolving out of calcareous fossils. The rock is of chemical origin
— that is, results from the precipitation of silica from solution, and
presumably through the action of organic matter. In France the
material occurs alternating with other unaltered Tertiary strata in
the Paris basin. It is also reported in Eocene strata in South
America, and in Burke and Screven counties along the Savannah
River in eastern Georgia in the United States. The toughness
of the rock, together with the numerous cavities, imparts a sharp
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OXIDES. t9
cutting power such as renders it admirably adapted for millstones,
and in years past material for this purpose has been sent out from
French sources all over the civilized world.
ItipoU is the commercial name given to a peculiar porous rock
associated with the Lower Carboniferous limestones of soutiiwest
Missouri, and regarded as having originated through the leachmg
out of the lime carbonate from a higUy siliceous member of the
series.^ The rock is of a cream-white or slight pink cast, fine grained
and homogeneous, with a distinct gritty feel, and, though soft, suf-
ficimtly tenacious to permit of its being used in the form of thin
disks of considerable size for filtering purposes. According to Hovey ^
the deposit is known to underlie between 80 and 100 acres of land,
in the form of a rude ellipse, with its longer diameter approximately
north and south. From numerous prospect holes and borings it
bas been shown to have an average thickness of 15 feet, the main
quarry of the present company showing a thickness of 8 feet. The
following section is given from a well sunk in the northern part of
the area;
E»rtli o to 4
Tripoli 4 30
Stiff red day lo aij
Mixsd cbett, day, and ocber ai) 40
Cherty limestone 40 93
Cherly limestone bearing galena. 93 1,03
Limestone 103 I38
Limestone bearing spbaleritc and galena 1 38 136
Soft msgncsian limestone — 136 173
The tripoli is everywhere underlain by a relatively thin bed of
stifi red clay, and also traversed in every direction by seams of the
same material from i to 3 inches thick. These seams and other
joints divide the rock into masses which vary in size up to 30 inches
or more in diameter. Microscopic examinations as given by Hovey
show the rock to contain no traces of organic remains, but to be
made up of faintly doubly refracting chalcedonic particles from 0.01
to 0.03 millimeter in diameter. The chemical composition, as
shown from analysis by Prof. W. H, Seaman, is as follows:
' Bulletin No. 340, U, S. Geological Survey, 1908, p. 433-
• Scientific American Supplement, July a8, 1894, p. 15487.
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THE NON-METALLIC MINERALS.
Percent.
98.100
0,140
0.008
Iron oride (FeO and FcjO,)
■■»■■»■
The material boiled in a 10 per cent solution of caustic soda for
three hours, yielded 7,28 per cent soluble silica.
Aside from its use as a filter the rock is crushed between buhr-
stones, bolted, and used as a polishing powder. To a small extent it
has been used in the form of thin slabs for blotting purposes, for
which it answers admirably, owing to its high absorptive property,
but is somewhat objectionable on account of its dusty character.
The view (Plate III) shows the character of a quarry of this material
as now worked by the American Tripoli Company at Seneca, in
Newton County.
Diatomaceous or infusorial earth, as it is sometimes wrongly
called, is, when pure, a soft, pulverulent material, somewhat resem-
bling chalk or kaolin in its physical properties, and of a white or
yellowish or gray color. Chemically it is a variety of opal (see analy-
ses on p. 72),
Origin and occurrence of deposits. — Certain aquatic forms and plant
life known as diatoms, which are of microscopic dimensions only,
have the power of secreting sOica in the same manner as mollusks
secrete carbonate of lime, forming thus their tests or shells. On
the death of the plant the siliceous tests are left to accumulate on the
bottom of the lakes, ponds, and pools in which they lived, form-
ing in time beds of very considerable thickness, which, however,
when compared with other rocks of the earth's crust, are really of
insignificant proportions. Like many other low organisms the
diatoms can adapt themselves to a wide range of conditions. They
are wholly aquatic, but live in salt and fresh water and under widely
varying conditions of depth and temperature. They may be found
in living forms in almost any body of comparatively quiet water
in the United States. The exploring steamer Challenger dredged
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OXIDES. 71
them up in the Atlantic from depths varying from 1,260 to 1,975
fathoms, and from latitudes well toward the Antarctic Circle. Mr.
Walter Weed, of the U. S. Geological Survey, has recently reported
them as living in abundance in the warm marshes of the Yellow-
stone National Park, while Dr. Blake reported finding over 50
species in a spring in the Pueblo Valley, Nevada, which showed a tem-
perature of 163° F.
Although beds of diatomaccous earth are still in process of forma-
tion, and in times past have been formed at various epochs, the
Tertiary period appears for some reason to have been peculiarly
fitted for the growth and preservation of these organisms, and all of
the known beds of any importance, both in America and foreign
countries, are of Tertiary .^ge. The best known of the foreign
deposits is that of Bilin, in Bohemia. This b some 14 feet in thick-
ness. When it is borne in mind that, according to the calculations
of Ehrenberg, every cubic inch of this contains not less than 40,000,-
000 independent shells, one stands aghast at the mere thought of the
myriads of these litUc forms which such a bed represents. Some of
the deposits in the United States are, however, considerably larger
than this. What is commonly known as the Richmond bed extends
from Herring Bay, on the Chesapeake, Maryland, to Petersburg,
\'irginia, and perhaps beyond. This is in some places not less than
30 feet m thickness, though very impure. Near Drakesville, in
New Jersey, there occurs a smaller deposit, covering only some 3
acres of territory to a depth of from i to 3 feet. Some of the largest
deposits known are in the West. Near Socorro, in New Mexico,
there is stated to be a deposit of fine quality which crops out in a
single section some 6 feet in thickness for a distance of 1,500 feet.
Geologists of the fortieth-parallel survey reported abundant de-
posits in Nevada, one of which, in the railroad cutting west of Reno,
showed a thickness not less than 300 feet, of a pure white, pale
buff, or canary-yellow color. Along the Pitt River, in Cahfomia,
there is stated to be a bed extenduig not less than 16 miles, and in
some places over 300 feet thick {see Plate IV). In the northern
part of Santa Barbara County the earth occurs m quantities which
are seemingly truly mexhaustible. In the region about Lompoc,
south of the Santa Inez River, beds are exposed over an area of at
least 3 square miles, and wliich have, in places, a thickness of
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72
THE NON-METALLIC MINERALS.
SEveral hundred feet.' Four miles west of Lompoc i,ooo feet in
thickness of beds are exposed, and in the Burton Mesa the "pure
diatomaceous earth " is stated to be 2,000 feet in thickness. Numer-
ous other localities are mentioned where the material is almost equally
abundant.2 Near Linkville, Klamath County, Oregon, there occurs
a deposit which has been traced for a distance of ro miles, and shows
along the Lost River a thickness of 40 feet. Beds are known also
to occur in Idaho, near Seattle, in Washington, and doubtless many
more yet remain to be discovered. A deposit of unknown extent,
pure white color, and almost pulp-like consbtency, has been worked
in South Beddingham, Maine. Others of less purity occur near
South Framington, Massachusetts, Lake Umbagog, New Hamp-
shire, at Whitehead Lake, Herkimer County, New York, and at
Grand Manan, New Brunswick.
Chemical composition. — As already intimated, this earth is of a
siliceous nature, and samples from widely separated localities show
remarkable uniformity in composition. Of the following analyses,
No. I is from Lake Umbagog, New Hampshire, No. II from Morris
County, New Jersey, and No. Ill from Pope's Creek, in Maryland.
As will be noted, the silica percentage is nearly the same in all.
ConstituenW.
I.
11.
III.
80 -53
5-89
I -03
0-3S
80.66
3-84
""o\\k'
81 -5J
3-43
6.04
Water and organic malter
11.03
.4.01
The substance may therefore be regarded as a variety of opal.
Uses. — The main use of diatomaceous earth is for a polishing
powder. It is, however, an excellent absorbent, and has been utilized
to mix with nitroglycerine in the manufacture of dynamite. It has
' A block ol this material some 5 feet in diam
lections of the National Museum is reported as con;
diatoms, and 35 per cent of sponge spicules and r
fonns among the diatoms are Coscinodiscus robuslu:
■Xei among the geological col-
!sling of some 75 per cent of
idiolaria. The most abundant
Aainoptyckus uttdulalus, and
RalfHi, two species ot Raphontui, Biddulpkia aurila, and an undetermined species
of Synedra.
' Bulletin No. 315, U. S. Geological Survey, 1906, p. 438.
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PLATE IV.
Bed of Diaiom Earlh, Great Bend of Pitt River, Shasta County, California.
(From photograph by J. S. Diller, U. S. Geological Survey J
[Facing page 72.]
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jvGooi^lc
OXIDES. 73
also been used to some extent in the preparation of the soluble silicate
known as water glass, and still again as a non -conductive material
for steam boilers, etc. The demand for the material is quite small,
not nearly equal to the supply. The Maryland and Nevada de-
posits are the principal ones now worked. During the year 1897
the entire output was about 3,000 tons, valued at some $30,400.
2. CORUNDUM AND EMERY.
Conindimi, — Composition, sesquioxide of aluminum, AIjO,,
^oxygen, 47.1 per cent; aluminum, 52.9 per cent. In crystals
Fig. ij. — Conindum crystals, characteristic forms.
[U. S. National Museum.]
often quite pure, but frequently occurring associated in crystalline
granular masses with magnetic iron, and often more or less altered
into a scries of hydrated aluminous compounds, as damourite. The
crystalline form of the mineral is hexagonal, or siz-sided In outline,
often with cur\-ed sides and square terminations, giving rise to
roughly barrel-shaped forms, as shown in Fig. 13.
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74 THE NONMET^LUC MINERALS.
A pnjminent basal cleavage causes the crystals to break readily
with smooth flat surfaces at right angles with the axis of elongation.
The massive forms frequently show a nearly rectangular parting or
pseudo-cleavage.
The most striking physical property of the mineral is its hard-
ness, which is 9 of Dana's scale. In this respect it ranks then next
to the diamond. The color varies from white through gray, brott-n,
yellow, blue, pink, and red; luster, adamantine to vitreous; specific
gravity, 3.95 to 4.1. The highly colored transparent red and blue
forms are valuable as gems, and are known under the names of
ruby and sapphire. The consideration of these forms is beyond the
limits of this work.
Occurrence. — Although widespread as a mineral, corundum un-
mixed with a large proportion of magnetite (forming emery) has been
found in comparatively few localities in sufficient abundance to be
of commercial value. The most important deposits known in the
United States are in southwestern North CaroUna, the Laurel
Creek region of northern Georgia, and central Montana. Within
a few years corundum-bearing syenites, covering an area of many
square miles, have been found in Renfrew, Hastings, and Halberton
counties in Ontario, Canada.
According to Pratt, most of the corundum that has been mined
in the United States for abrasive purposes has been obtained from
the eastern part of the section, where it is associated with a long belt
of basic magnesian rocks (perklotites) extending from Tallapoosa
in east central Alabama, to Trenton, New Jersey, with disconnected
outcrops north of New Jersey, as in Connecticut, Massachusetts,
New Hampshire, and Maine.. In the southern portion of this belt
the perklotites have reached .their greatest development, in some
localities outcropping over an area of several hundred acres. At
Webster, in Jackson County, North Carolina, the peridotite occurs
intrusive in the homblendic gneiss, the corundum occurrmg in great-
est abundance at or near the line of contact between the two rocks.
Associated with the corundum are nearly always at thb locality a
series of secondary minerals, including vermiculite, chlorite, and
talcose, and serpentinous materials.
An ideal cross-section of one of the corundum contact veins at
ovGoO'^lc
OXIDES. 75
Corundum Hill, in Macoa County, is shown in Fig. 14, while a map
of the country, showing the character of the surrounding rocks,
is shown in Fig. 15. The mine at Corundum Hill has been until
recently one of the most important in the country, and may be
described in some detail as illustrating the mode of occurrence of the
materiaL The formation here is a rather blunt, lens-shaped mass
Fig. 14, — Ideal cross-scclion of a corundum contact veiD at Corundum Hill Min^
North Carolina; a, fresh and unaltered gneiss; b. dextyed gneiss; c. vermiculite;
d, green chlorite; e. corundum -bearing zone; /. green chlonte, g, enstatite; h, talcow
rock; i, clay; ;, altered dunite; k. unaltered dunite.
[U. S. Geological Survey.]
of peridotite (dunite) exposed over an area of about 10 acres. A
number of veins have been worked, but, with the exception of the
one marked "Shaft" on the map, they have soon pinched out.
Most of the mining has been done on the south side of this for-
mation, as described by Pratt, by means of open cuts, and later by
tunnels. Plate V shows the entrance to this tunnel, with the peri-
dotite on the left and the gneiss on the right beyond the cut. For
neariy the whole distance of the southern boundary of the dunite
formation a cut has been made, following the contour of the hilL
This is sometimes wholly within the gneiss, and at other times wholly
within the peridotite, and again cutting directly across the contact.
The tunnels are all to the left of the cut, and have encountered
corundum almost continuously for a distance of 1,280 feet.'
' These mines have now liyog) been for several years abandoned.
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76 THE NON-MET/fLLlC MINERALS.
The materials collected from the mines at Corundum Hill are
in the forms known as block, crystal, and sand ores. The mean-
ing of the terms is obvious. A small amount of garnet is occasionally
found associated with the corundum in the vein along the southern
contact.
f^^ E3 ^ ^M
Fig. 15. — Map of peridot ite formation at Corwndum Hill, Macoo County, N. C
[U. S. Geological Survey.]
At what is known as the Buck Creek, or CuUakeenee Mine,
about 20 miles southwest of Franklin in this same county,
corundum is found associated with a compact mass of peridotite,
covering about three-quarters of a square mile, forming the largest
mass that is known in the Appalachian belt. A topographic map
6f this area, showing the association of the various tx)cks, is shown
in Fig. 16.
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PLATE V.
VciD between Peridotite and Gneiss, Corundum Hill, Macon Couniy, North Carolina.
[After J. H. Prall, Bullelin No. 180, U. S. Geological Survey,]
[Fating page ^6.■\ ^,^^\c
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OXIDES. 77
The vein here is described as differing from most of the corundum
veins in the peridotite rocks in that it is composed essentially of
plagioclase feldspar, and hornblende, which bear a relation to each
other similar to that of the feldspar, quartz, and mica in pegmatite
dikes. There is an abundance of ore at this mine, but it has been
as yet unexploited, owing to difficulty of transportation.
F1C.16, — Mapof the Buck Creek peridotite area, showing the lelatian of the ai
lite dikes.
[U. S. Geological Survey.]
At Laurel Creek, in Georgia, on what is known as Pine Moun-
tain, in Rabun County, there is a large outcrop of peridotite coverii^
several hundred acres, along the contact of which with the gneiss large
deposits of corundum have been found. Fig. 1 7 shows the relation of
the gneiss and the perido'ite. The formation here occupies two small
hills, which, on account of their rough and barren nature — a feature
characteristic of regions occupied by iron magnesian rocks — offer
a sharp contrast to the surrounding country. A large open cut on
the east side of the formation follows, for the most part, along the
contact to a depth of some 200 feet. (Plate 6, Fig. 1.) At its lower
end this cut encounters what is known as the Big or Dunite Vein of
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78
THE NON-METALLIC MINERALS.
massive corundum, the cut having followed on a contact vein of
crystallized corundum. Although this vein is near the contact of
the peridotite with the gneiss, it is separated from the same by a
band of peridotite and a small vein of sand corundum. This has
been one of the most famous mines in the country, and has furnished
ore of an exceptionally high grade.
Fio. 17. — Map of the peridotite formation at Laurel Creek, Rabun Coaut^, Georgia.
[U. S. Geological Survey.]
A large part of the corundum that has been found in Montana
is of the sapphire variety, and is used as gem material. Hence its
consideration belongs properly to a treatise on gems. But at one
locality, not far from Bozeroan, in Gallatin County, corundum, in
well-defined hexagonal crystals, of all sizes up to 10 millimeters in
diameter and 20 to 30 millimeters in length, "has been found in
considerable quantity in an igneous rock composed essentially of
ortbodase feldspar, corundum, and biotite. The rock has at tiroes
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Fig. I. — Corundum Vein al Laurel Creek, Georgia.
[After J. H. Prart, Bullelin No, i8o, U. S. Geological Survey.]
Fio. J.— Bauxite Bed, Saline County, Arkansas,
n photograph by C. \V. Hayes, U. S, Geological Survev.]
PLATE VL CoOQIc
[Facing page ^S.]
J, Google
a somewhit gneissic structure, and in these portbns the corundum
is found in a more or less finely divided condition, and in other
portions, where the rock has a pegmatitic character, the corundum
is coarsely crystallized and surrounded by orthoclase. The per-
centage of corundum is quite large. The colors vary from bluish
gray to almost colorless.
Near the entrance of Yogo Gulch, in Fergus County, in this
same State, feldspathic igneous rocks allied to the minettes have
been found carrying sapphires. The rock occurs in the form of
two parallel dikes about 800 feet apart, which can be followed for
over a mile in a nearly east-and-west course, their general width
being from 6 to 20 feet. The rock, which is much decomposed
on the surface, has a dark gray, decidedly basic appearance, and
is very tough. The sapphires are mainly of some shade of blue, and
occur in the form of sharp, distinct crystals. The material is used
wholly for gem purposes.
In Ontario, Canada, the corundum occurs as a primary constitu-
ent of syenite, the rocks varying from a normal syenite to a nepheline
syenite and a mica syenite, the mineral being most abundantly
developed in the normal syenite. The rocks occur as dikes cutting
through the gneisses, the corundum existing in such abundance as to
average perhaps 12 per cent of the entire mass, and in crystab of
all sizes up to 50 millimeters in diameter. The principal areas thus
far discovered, as shown in the accompanying map (Fig. 18), occupy
an area some 75 miles in length extending from Renfrew County
westerly through Hastings into Haliburton, with smaller areas in
Peterborough and Frontoiac coimties.
The corundum deposits of India have been described by T. H.
Holland.' The mineral here occurs in a matrix of deep flesh-colored
feldspar, which is in bands or lenticular masses and has associated
with it often a considerable portion of sillimanite, rutile, spinel,
and mica.
Corundum in what is apparently commercial quantities has
been reported in the ranges near Mts. Painter and Pitts in South
Australia. The mineral occurs in the form of segr^ation lumps,
' Geology of iDdia, Part lit, Economic Geology.
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So THE NON-METALLIC MINERALS.
rough hexagonal crystals and irregular shaped masses disseminated
throughout a schistose metamorphic rock consisting mainly of black
mica.
Origin, — The origin of the corundum in the occurrences above
noted can be in part surmised from the descriptions which have
been given. It is evident that, in the majority of cases, such result
from the direct crystallization of aluminum oxide from a molten
Fig. i8. — Map of corundum areas of Canada.
Experimental work by Morozewicz ' has shown that from super-
saturated alumina-silicate magmas deficient in the alkalies, lime,
magnesia, and iron, the alumina may all separate out as corundum.
With increasing amounts of the alkalies and lime, the feldspars, in
varying proportions, may appear. The presence of magnesia and
iron is likely to give rise to minerals of the spinel group, as well.
These results are all in accord with Montana, North Carolina and
Canadian occurrences and may pix>bably be considered as hoal.
' Tschennak's Min. u. Petr. Mitthdl.. XVIII, 1898.
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OXIDES.
8i
The sapphires occurring in the basic rock from Yogo Gulch,
Montana, are regarded by Pirsson^ as of pyrogenic origin, that is,
as resulting from the direct crystaUization of the oxide, which has
in this case been derived from aluminous material dissolved from
shales by the molten rock during its intrusion. It seems most
probable that the Indian corundum, even including the ruby of
Burmah, is of secondary origin — a result of metamorphism.
Emety, — The rock emery takes its name from Cape Emeri, on
the island of Naxos, where it occurs in great abundance. Mineral-
ogically it has been regarded by various authorities as either a mechan-
ical admixture of corundum and magnetic iron ore or as simply a
massive iron spinel — hercynite. So far as the Naxos emery is con-
cerned, the first view in imdoubtedly correct, the two minerals
occurring in about the proportion of two parts of corundum to one
of magnetite and other minerals. Physically emery is a massive,
nearly opaque, dark-gray to blue black or black material, with a
specific gravity of 4 and hardness of 8, Dana's scale, breaking with
a tolerably regular fracture, and always more or less magnetic.
Chemically the material is quite variable. Below are the results
of analyses by Dr. J, Lawrence Smith, from whose papers on the
subject these notes are partially compiled.
LooJitie*.
Alumina.
Iron.'
Umt.
Sine*.
W.ter.
61 -OS
63-5°
70.10
60.10
44-OI
51-93
»7-'S
33-25
i:i
33 ■«
So.ai
44.11
4».as
19 -S'
9.63
1-30
If.
V.&
1.40
9-63
1.61
vz
8.13
4.1a
6.88
1.80
3.<3
S-'S
S-46
S-48
4.81
1.00
Swnos
S.6»
Nicaris j
»-53
Chesler, Massachusetts.
' American Journal of Science, Vol. IV, 1894. P- 4*-
' It is stated that the American Plate Glass companies, while accepting aa emery
carrying as high as 60 per cent Fe,0,, will not accept this in the form of an arti&cial
admixture of corundum and magnetite. It mtist be the natural, crystalline
admixture.
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83 THE NON-MET^LUC MINERALS.
Geologically emery, like corundum, belongs to the older crystal-
line rocks. In Asia Minor it occurs in angular or rounded masses
from the size of a pea to those of several tons weight, embedded
in a blue-gray or white crystalline limestone, which overlies mica-
ceous or homblendic schists, gneisses, and granites. Superficial
decomposition has, as a rule, removed more or less of the more
soluble portions of the limestone, leaving the emery nodules in a red
ferruginous soil. With the emery are associated other aluminous
minerals as mentioned below.
According to Tschermak' the Naxos emery occurs mostly in the
form of an iron-gray, scaly to schistose, rarely massive, aggregate
consisting essentially of magnetite and corundum, the latter mineral
being in excess. In addition to these two minerals occur hematite
and limonite, as alteration products of the magnetite. Margarite,
muscovite, biotite, tourmaline, chloritoid, diaspore, disthene, stauro-
lite, and rutile occur as common accessories; rarely are found
spmel, vesuvianite, and pyrite. Under the microscope he finds the
emery rock to show the corundum in rounded granules and some-
times well-defined crystals with hexagonal outlines, particularly in
cases where single individuals are embedded in the iron ores. (Plate
VTI, Fig. 2.) In many cases, as in the emery of Krenino and
Pesulas, the granules are partially colored blue by a pigment some-
times irregularly and sometimes zonally distributed. The corundum
grains, which vary in size between 0.05 mm. and 0.52 mm. (averaging
about 0.22 mm.), are very rich in inclosures of the iron ores, largely
magnetite in the form of small, rounded granules. The quantity of
these is so great as at times to render the mineral quite opaque,
though at times of such dust-like fineness as to be translucent and of
a brownish color. The larger corundums are often injected with
elongated, parallel-lying clusters or groups of the iron ores, as
shown in Fig. 3, of the plate from Tschermak's paper, and are sur-
rounded by borders of very minute zircons. The iron ore, as noted
above, b principally magnetite, but which, by hydration and oxida-
tion, has given rise to abundant limonite. The magnetites are in
the form of rounded granules and dust-like particles, and also at
' Minenlogiicbe und Petrographiacbe Mittheilungen, XIV, 1S94, p. 313.
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PLATE VII.
Microstructurc of Emery.
[After Tscheimak, Min. u. Pet. Mittheil., XIV, Part IV.]
[Facing p<igt St.]
b, Google
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times in well-defined octahedrons. In their turn the magnetites also
inclose particles of corundum very much as the metallic iron of
meteorites of the pallasite group inclose the olivines, and as shown
in Fig. 4 of the plate.
The following account of these deposits and the method of work-
ing is by A. Gobantz: '
Naxos, the largest of the Cyclades Islands, is remarkable as being
one of the few localities in the world producing emery on a large
scale; the deposits, which are of an irregularly bedded or lenticular
form, being mostly concentrated on the mountains at the northern
end of the islands, the most important ones being in the immediate
vicinity of the village of Bothris. The island is principally made up
of Archaean rocks, divisible into gneiss and schist formations, the
latter consisting of mica schists altematii^ with crystalline lime-
stones. The lenticular masses of emery, which are quite variable
in size, ranging in length from a few feet to upward of loo yards
and in maximum thickness from 5 to 50 yards, are closely asso-
ciated with the limestones, and, Ss they follow their undulations,
they vary greatly in position, lying at all kinds of slope, from hori-
zontal to nearly vertical. Seventeen different deposits have been
discovered and worked at different times. These range over con-
siderable heights from 180 to 700 meters above sea-level, the largest
working, that of Malia, being one of the lowest. This important
deposit covers an area of more than 30,000 square meters, extending
for about 500 meters in length with a height of more than 50 meters.
This was worked during the Turkish occupation, and it has supplied
fully one-half of all the emery exported since the formation of the
Greek Kingdom. The highest quality of mineral b obtained from
two comparatively thin but extensive deposits at Aspalanthropo and
Kakoryakos, which are 435 meters above the sea-level. The mineral
is stratified in thin bands from i to 2 feet in thickness, crossed
by two ot^er systems of divisional planes, so that it breaks into nearly
cubical blocks in the working. The floor of the deposit is invariably
' Oesterreichische Zeitschrlft tUr Berg- und HUttenwesen, XLII, p. 143. Abstract
in the Minutes and Proceedings of the Institute of Civil Engineers, CXVII, pp. 466-
468.
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84 THE NON-METALLIC MINERALS.
crystalline limestone, and the roof a loosely crystalline dolomite
covered by mica schist. The underlying limestones are often
penetrated by dikes of tourmaline granite, which probably have
some intimate connection with the or^in of the emery beds above
them.
The working of the deposits is conducted in an extremely primi-
tive fashion. The rock b first broken by fire-setting, A piece of
ground about 5 feet broad is cleared from loose material, and a
pile of brushwood heaped against it and lighted. This bums out
in about twenty-four or thirty hours, when water is thrown upon the
heated rock to chill it and develop fractures along the secondary
divisional planes in the mass of emery, and so facilitate the breaking
up and removal of the material. Sometimes a crack is opened
out by inserting a dynamite cartridge, but the regular use of explosives
is impossible as, owing to the hardness of the mineral, it can not be
bored with steel tools.
The only deposits of emery at present worked in the United
States occur on what are known as North and South Mountains,
near Chester, in Hampden County, Massachusetts, and Peekskill
in Westchester County, New York. The Chester deposits were
first described by Dr. C. T, Jackson (in 1864) and developed by
Dr. H. S. Lucas, the material being at first regarded as mainly
magnetite and worked as an iron ore.
The vicissitudes of the operations here, like those of the chromite
deposits near Baltimore, form one of the interesting chapters in the
history of mining operations in the United States, but which can not
be here touched upon.
The deposits have been frequently described, as noted in the
bibliography, the facts which are here given being derived mainly
from the recent works of B. K. Emerson and J. H. Pratt. The
country rock is schistose epidotic-amphibolite of doubtful origin, but
which Pratt thinks may be an altered eruptive. The emery-bearing
veins conform in a general way with the winding of the schbt, and
have a strike of approximately north 20° east, south 20° west, dip-
ping to the eastward at an angle of some 70°, As first shown,
where cut by the Westfield River, the vein is very narrow, but
widens rapidly to the north, attaining a width of 17 feet, of which
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OXIDES.
85
some 10 feet are emery, the remainder being mainly magnetite.
The vein, or bed, cuts through both North and South Mountains,
and has been traced a distance of some 5 miles, though the emery
is not continuous for the entire distance. It can, however, be traced
by means of streaks of chlorite (corundophillite) which almost invari-
ably accompany it. Othw characteristic associates are the above noted
margarite and magnetite,
talc, and black tourma-
line, the vein material it-
self being described as a
chloritic m^netite con-
taining in abundance
bronze-colored grains of
emery and, along the
borders of the thicker
portion of the main
vein and of the eastern
vein, a considerable
quantity of brown-black
tourmaline in delicate
stellate forms. The part
of the vein rich in emery
shows the material in the
form of a dark gray,
nearly black massive
rock, throughout which
the corundum is dis-
seminated in the form
of small crystals, some-
times 5 to 15 millimeters in diameter and of
color.
Six mines have fropi time to time been opened on this deposit,
as shown in Fig. 19. At the Melvin Mine the vein varies from
6 to 16 feet in width. A cross-section of the Old Mine is given
in Fig, 20. The limits of the deposit as given by Emerson are:
Length, 4 miles; depth, 750 feet (above the level of the brook),
and with an average width of 4 feet.
-jm
t
%
Fio. 19. — Map showing location of emery deposits
at Chester, Massac husetts.
[U. S. Geological Siirver.]
a rich bronze
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86 THE NON-METALLIC MINERALS.
The origin of this ore
has, naturally, been a mat-
ter of some speculation,
Emerson regards it as most
probable that the emery-
magnetite material was
originally a deposit of lim-
onite, which was formed
by the replacement of lime- S
stone, and into which alu- ^
mina was carried by infil- S"
trating solutions and de- *
posited as allophane and -|
gibbsite, ultimately altered
into corundum and mag-
netite by metamorphism. "S
Pratt, on the other hand, |
r^ards the amphibolite as |
probably an altered eruptive ^ ij
rock, and argues that the »»
magnetite and corundum I c
are both segregations of "■
basic materials from the .§
igneous magma, i.e., are ^
products of magmatic dif- O
ferentiation. ^
The Feekskill emery oc- «
curs in the form of a hard, |
dark gray to nearly black i
rock which the microscope \
has shown to consist es- ^
sentially of corundum, spi- ^
nel, and magnetite, the first
named in varying propor-
tions up to 50 per cent of
the mass. It is associated
in the form of lenses and
I
i
J, Google
OXIDES. 87
bands, with intrusive rocks — gabbros — from which it was doubtless
derived by a process of magmatic segregation. The extent of the
individual deposits is very irregular and unreliable. The mines
are all open cuts located on natur^ outcrops, the yield from any
one opening being rarely over 100 tons and frequently much less.
The annual output is but 500 to 700 tons, and the material
regarded commercially as inferior to that of Naxos, but well
adapted for emery wheels and like purposes.
Sources. — ^The chief foreign commercial sources of emery are those
of Gumuch-dagh, between Ephesus and the ancient Tralles: Kulah,
and near the river Hermes in Asia Minor; and the island of Naxos,
whence it is quarried and shipped from Smyrna, in part as ballast,
to all parts of the world. The chief commercial source in the
United States, or indeed, in North America, is Chester, Massachu-
setts, and PeekskiU, New York, as above noted. The island of
Naxos b stated to have for several centuries furnished almost
exclusively the emery used in the arts, the material being chiefly
obtained from loose masses in the soil. The mining at Kulah
and Gumuch-d^h was begun about 1847, and at Nicaria in
1850.
Uses. — In preparing for use, the mineral, after being dug from the
soil or blasted from the parent ledge, is pulverized and bolted in
various grades, from the finest flour to a coarse sand, the excess of
magnetite, where such exists, being extracted by means of an electro-
magnet The commercial prices vary according to grade from 3 to
10 ceats a pound.
The chief uses of both emery and corundum, as is well known,
are in the form of powder by plate-glass manufacturers, lapidaries,
and stone workers; as emery paper, or in the form of solid disks
made from the crushed and bolted mineral and cement, known
commercially as emery wheels. The great toughness and superior
cutting power of these wheels render them of service in grinding
glass, metals, and other hard substances, where the natural stone is
quite inefficient.
An "emery" recently put upon the market consists of an artificial
admixture of Canadian corundum and magnetite. The cutting
power of the mixture is less than that of the natural emery, where
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88 THE NON-METALLIC MINERALS.
the two substances are so closely intercrystallized, and among those
who know, it will rarely be accepted as an equivalent.
(See further under Grind- and Whetstones, p. 400.)
BIBLIOGRAPHY OF CORUNDUM AND EMERY.
J. Lawkxhce Smith. Memoir on Emery — First part — On ihe Geology and Miner-
alogy of Emery, from observations made in Asia Minor.
American Journal of Science, X, 1850, P- 3S4-
Memoir on Emery — Second Part — On the Minerals associated w.t Emery.
American Journal of Science, XI, 1851, p. 53.
Charles T. Jaceson. discovery of Emery in Chester, Hampden County, Massa-
chusetts.
Proceedings of the Boston Society of Natural History, X, 18S4, p, 84.
American Journal of Science, XXXIX, 1865, p. 87.
Chakles U. Shepakd. A Description of the Emery Mine of Chester, Hampden
County, Massachusetts.
Pamphlet, 16 pp., London, 1S65.
J, Lawrence Smith. On the Emery Mine of Chester, Hampden County, Massachu-
setts.
American Journal of Science, XLII, 1866, pp. 83-93.
Original Researches in Mineralogy and Chemistry, 1884, p. Iii.
C. W. JeneS. Corundum of North Carolina.
American Journal of Science, III, 1871, p. 301.
Chaiu.ee U. Shepakd. On the Corundum Region of North Carolina and Georgia.
American Journal of Science, IV, 1873, pp. rog and 175.
FSedekice a. Gehth. Corundum, its Alterations and Associated Minerals.
Proceedings of the American Philosophical Society, XIII, 1873, p, 361.
C. W. Jenks. Note on the occurrence of Sapphires and Rubies in situ with Coiun-
duro, at the Culsagee Mine, Macon County, North Carolina.
Quarterly Journal of the Geological Society, XXX, 1874, p. 303.
W. C. Kerb. Corundum of North Carolina,
Geological Survey of North Carolina, I, Appendix C, 1875, p. 64.
C. D. SiOTH. Corundum and its Associate Rocks.
Geological Survey of North Carolina, I, Appendix D, 1875, pp. 91-97.
R. W. Raymond. The Jenks Corundum Mine, Macon County, North Cardina.
Transactions of the American Iikstitute of Mining Engineers, VII, 1878, p. 83,
J. Ylrtcax. Cotundum in North Carolina.
Proceedings, Academy of Natural Sciences, Philadelphia, XXX, 1878, p. 333.
F. A. Genth. The so-called Emery-ore from Chelsea, Bethel Township, Delaware
County, Peimsylvania.
Proceedings, Academy of Natural Sciences, Philadelphia, XXXII, i8Se^ p. 311.
C. D. Smith. Corundum.
Geological Survey of North Carolina, II, r88i, p. 43.
F- A. Genth. Contributions to Mineralogy.
ProceetUngs of the American Philosophical Society, XX, i88a.
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OXIDES 89
T. M, Chatard. Corundum and Emery.
Mineral Resources of the Uniled States, 18S3-84, p. 714.
The Gneiss-Dunyle Contacts of Corundum Hill, North Carolina, in lelatko
to the Origin of Corundum.
Bulletin No. 42, U. S. Geological Survey, 1887, p. 45.
G. H. Williams. Noriles of the "Cortlandt Series."
American Journal of Sdence, XXXIII, 1887, p. 194.
F. A. Gekth, Contributions to Mineralogy.
American |ournal of Science, XXXIX, 1890, p. 47.
A. GoBADTZ. The Emery Depouts of Naios.
Engineering and Mining Journal, LVIII, 1894, p. 394.
Fkahcis p. King. Corundum Deposits of Georgia.
Bulletin No. 2, Geological Survey of Georgia, 1894, 133 pp.
T. D. Pahet. Emery and Other Abrasives.
Journal of the Franklin Institute, CXXXVII, 1894, pp. 353, 411.
J. C. Trautwine. Corundum with Diaspore, Culsagec Mine, North Caiolina.
Journal of the Franklin Institute, XCIV, p. 7.
J. VOLNEY Lehis. Corundum of the Appalachian Crystalline Bell.
Transactions of the American Institute of Mining Engineer^ XXV, 1895, p. 85s,
■ The Corundum Linds of Ontario.
Canadian Mining Review, XVII, 1S9S, p. 191.
B. K. EUEBSON. Moni^raph, XXIX, U. S. Geological Survey, 1898, p. 117.
J. H. Pratt. Bulletin No. 180, U. S. Geological Survey, 1901.
H. C. Uaohts. Twenty-third Annual Report State Geologist of New York, 1903.
F. D. Adaus and A. E. Baklow. Nephelin and Associated Alkali Syenites oE
Eastern Ontario.
Transactions of the Royal Society of Canada, II, 1908-09.
3, BAUXITE.
Composition. — AUOa-aHjO, —alumina, 73.9 per cent; water, 26.1
per cent. Commonly impure through the presence of iron oxides,
silica, lime, and magnesia. Color, white or gray when pure, but
yellowish, brown, or red through impurities. Specific gravity, 2.55;
structure, massive, or earthy and clay-like. According to Hayes '
the bauxites of the Southern United States show considerable variety
ID physical appearance, though generally having a pronounced
pisolitic structure. The individual pisolites vary in size from a
' The Geological Relations of the Southern Appalachian Bauxite Deposits.
Transactiona of the American Institute of Mining Engineers, XXIV, 1894, pp.
850-251
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go THE NON-METAUIC MINERALS.
fraction of a millimeter to 3 or 4 centimeters in diameter, although
most commonly the diameter is from 3 to 5 millimeters. The matrix
in which they are embedded is generally more compact and also
lighter in color. The larger pisolites are composed of numerous
concentric shells, separated by less compact substance or even open
cavities, and their interior portions readily crumble to a soft
powder.
In thin sections the ore is seen to be made up of amorphous
flocculent grains. The matrix in which the pisolites are embedded
may be composed of this flocculent material segregated in an irregulary
globular form or in compact oolites, with sharply defined outlines.
Or both forms may be present, the compact oolites being embedded
in a matrix composed of the less definite bodies. In some cases the
interstices between the oolites are filled either wholly or in part with
silica, apparently a secondary deposition.
The pisolites also show considerable diversity in structure. In
some cases they are composed of the same flocculent grains as
tiie surrounding matrix, from which they are separated by a thin
shell of slightly denser material. This sometimes shows a number
of sharply defined concentric rings, and is then distinctly separa'.ed
from the matrix and the interior portion of the pisolite. The latter
is also sometimes compos"d of imperfectly defined globular masses,
and in other cases of compact, uniform, and but slightly granular
substance. It is always filled with cracks, which are regularly radial
and concentric, in proportion as the interior substance has a uniform
texture. Branchii^ from the larger cracks, which, as a rule, are
partially filled with quartz, very minute cracks penetrate the inter-
vening portions. Thus the pisolites appear to have lost a portion
of their substance, so that it no longer fills the space within the outer
shell, but has shrunk and formed the radial cracks. No analyses
have been made of the difl'erent portions of the pisolites or of the
pisolites and matrix separately, and it is impossible to say whether
any differences in chemical composition exist. It may be that some
soluble constituent has been removed from the interior of the pisolites,
but it is more probable that the shrinking observed is due wholly to
desiccation.
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Scattered throughout the ground mass are occasional fragments
of pisolites, whose irregular outlines have been covered to varying
depths by a deposit of the same material as forms the concentric
sheik, and thus have been restored to spherical or oval forms.
The following table will serve to show the wide range of com-
position of bauxites from various sources:
I VAKIOOS LOCALITIES.
L««lhi«.
ao»
TiO,
AlA.
Pe^,
H,0. H,0,
Pfii. Analyat.
1. Baux. France:
37 ^Sj
91. OS
ii
J.JS
30.3
6fl.30
,6.9c
64.14
4'^J''
48.91
61. IS
48:8
.4.3S
i.Sj
1%
I'i
'oeville.
c. Hard and compaci
"".46
B°-
4. Viiieve,-™c. H^rauit
France, whita vanely.
J. Wochein. Germany
6. Lan«dorF, Gennony:
tferiS."':::::::-
;i:li
'3,
LLJl.
7. Vi«clsberg, Germany
Pkilli^ ■
20.43|' .6s
lo. Floj^Co., GeoiBia
Nichols
J.JO
■ .(.8
16.76
ij. Bamsl^y Estate, Dinwiiid
Slation.Gwrtria. .\-o. 7..
14. Pulaski Co.. Arkansas:
fsVi
ProF. H. C.
White
I I:;;;;;;;;;-'
'l-^^±
14' 86
■ K^,
h. No. j.-o.) CaCOj, No. j.-ii.t CaCO,. No. j
FeO + F=^,. No. 7.— 0.8s C»0 o.j8 MeO. o.,o &
MgO, 0.09 K,0 o.Tj NbjO, trace COj. No. 9.— FeO 1
o.j6CO^ No, .0.— o,8oCa0.o,iCMB0.
det., 0.69 CaO. trace MsO. o.
Origin and mode 0} occurrence. — The mineral received its name
from the village of Baux (or Beaux') in Southern France, where a
highly ferriferous, pisolitic variety was first found and described by
Berthier in 1821. The origin of the mineral, both here and elsewhere,
has been a matter of considerab'e discussion. The following notes
' Hence the au should leceWe tbe •ound of long o, and not that of the au in oui
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9a THE NON-METALLIC MINERALS.
relative to the foreign occurrences are from a paper by R. L.
Packard ;'
The geological occurrence of the bauxite of Baux was studied
by H. Coquand ^ who describes the mineral as of three varieties,
pisolitic, compact, and earthy. The pisolitic variety occurs in highly
tilted beds alternating with limestones, sandstones, and clays, be-
longing to the Upper Cretaceous period, and in pockets or cavities
in the limestone. The limestone containing the bauxite and that
adjacent thereto is also pisolitic, some nodules being as large as the
fist. The pisolitic bauxite has sometimes a calcareous cement,
and at others is included in a paste of the compact mineral. Coquand
supposed that the alumina and iron oxide composing the bauxite
were brought to the ancient lake bed in which the lacustrine lime-
stone was formed, by mineral springs, which, discharging in the
bottom of the lake, allowed the alumina and iron oxide to be dis-
tributed with the other sediments. In some cases the discharge
occurred on land, and the deposit then formed isolated patches.
Sometimes the highly ferriferous mineral predominates over the
aluminous (white), at others diaspore is found enveloping the red
mineral, while in other cases it b mixed with it, predominating largely
and sometimes manganese peroxide replaces ferric oxide.
M, .\ng^3 describes the bauxite of Var and H^rault and gives
analyses. In the red mineral of Var druses occur with white bauxite
running as high as 85 per cent AI2O3, and 15 per cent H2O, cor-
responding to the formula AlgOa-l-HaO. He refers with apparent
approval to the prevailing theory of the formation of bauxite, accord-
ing to which solutions of the chlorides of aluminum and iron in contact
with carbonate of lime undergo double decompositfon, forming
alumina, iron oxide, and calcium chloride. Other deposits in the
south of France, in Ireland, Austria, and Italy, seem to him to con-
firm thb view, because they also rest upon or are associated with lime-
stone. The bauxite deposit in Puy de Ddme can not, however, be
explained by this theory, because it is not associated with limestone,
but rests directly upon gneiss and is partly covered by basalt. The
' ' Mineral Resources of the United Stales, 1S91, p. 14S.
' Bulletin de la SociA^ Gfolt^ique de France, XXVHI, 1S71, p. 98.
■Bulletin de la Soci^t^ G£o1ogique de Prance, XVI, 18SS, p. 345.
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OXIDES. 93
geological sketch map of the deposit near Madriat, Puy de D6me,
shows gneiss, basalt, with uncovered bauxite lai^ely predominating,
and patches of Miocene clay, while a geological section of the deposit
near Villeveyrac, H^rault, shows the bed of bauxite conformably
following the flexures of the limestone formation when covered by
more recent beds, and when exposed and denuded occupying cavities
and pockets in the limestone. This occurrence is substantially the
same as that of the neighboring Baux. M. Ang^ agrees with M.
Coquand in attributing the bauxite to geyserian origin, but uses as
an illustration of the contemporaneous formation of bauxite the
deposits from the geysers of the Yellowstone Park, which is evidently
due to a misunderstanding. No petrographical examination of the
bauxite of Fuy de Ddme was made nor any attempt to trace a
genetic relation between the latter and the accompanying basalt.
The occurrence is, however, noteworthy, and an examination might
show that it is another instance of the direct derivation of bauxite
from basalt, which is maintained somewhat imperfectly in the two
following instances.
Lang ' describes the bauxite in Ober-Hessen, as found in the
fi^ds in rounded masses up to the size of a man's head, embedded in
a clay colored with iron oxide. The chemical composition and
petrographical examination seems to show that it is a decomposition
product of basalt, . The process he explains as follows: By the weath-
ering of the plagioclase feldspars, augite, and olivine, nearly all the
silica had been removed, together with the greater part of the lime
and magnesia; the iron bad been oxidized and hydrate of alumina
formed. The residue of the silica had crystallized as quartz in the
pores of the mineral
A more detailed account of the derivation of bauxite from basalt
is given in an inaugural dissertation by A. Liebreich.^ The localities
described are the southern slope of the Westerwald near Miihlbach,
Hadamar, in the neighborhood of lesser Steinheim, near Hanau, and
especially the western slope of the Vogelsberg, Germany. Chemical
analyses show certain differences in the composition of samples from
■ Berichte der Deutschea Cbembchen Gesellschaft, XVII, 1S84, p. 3893.
' Abstiucted in ihe Chemiiches . eniralblalt, iSg>, p, 94.
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94 THE NON-METALLIC MINERALS
different places, the smaller amount of water in die Freoch bauxite
causing him to refer it to diaspore, while the Vofceisberg mineral is
probably gibbsite (hydrargillite). The Vogelsberg oauxlte occurs in
scattered lumps or small masses, partly on the surface and pardy
embedded in a grayish-white to reddish-brown clay, which contains
masses of basaltic iron ore and fragments of more or less weathered
basalt itself. Although the latter was associated intimately with the
bauxite, a direct and close connection of the two could not be found,
but an examination of thin sections of the Vogelsberg bauxite showed
that most specimens still possessed a basaltic (anamesite) structure,
which enabled the author to determine the former constituents with
more or less certainty. Lath-shaped portions representing altered
plagioclase feldspars filled with a yellowish substance preponder-
ated. Filling the spaces between these were cloudy, yellow, brown,
and black transparent masses which had eyidendy taken the place
of the former augite. Laths and plates of titanic iron, often fractured,
were commonly present, and the contours of altered olivine could be
clearly made out. The basalt of the neighborhood showed a structure
fully corresponding with the bauxite. Olivine and titanic iron
oxide were found in the clay by washing. The basaltic iron ore
also showed the same structure.
But two localities in the United States have thus far yielded bauxite
in commercial quantides. These are in Arkansas and the Coosa
VaUey of Georgia and Alabama.
According to Branner the Arkansas beds occur near the railway
in the vicinity of LitUe Rock, Pulaski County, and near Benton,
Saline County. The exposures vary in size from one to twenty
or more acres, and aggr^ate something over a square mile. This
does not, in all probability, include the total area covered by bauxite
in the counties mentioned, for the method of occurrence of the deposits
leads to the supposition that there are others as yet undiscovered.
Like all bauxite, the Arkansas material varies more or less in
cok)r and in chemical composition. At a few places it i5 so chained
with iron that attempts have been made to mine it for iron ore.
Some of the samples from these pits assay over 50 per cent of metallic
iron. This ferruginous kind is exceptional, however. From the
dark-red varieties it grades through the browns and yellows to pearl-
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Gooi^lc
Diqilizeobyl^OOQlC
OXIDES. 95
gray, cream colored and milky white, the pinks,~browns, and grays
being the more abundant. Some of the white varieties have the
chemical composition of kaolin, while the red, brown, and gray have
but litde silica and iron, and a high percentage of alumina. The
analyses given on page 91 show the composition of this bauxite as
compared with that of other localities.
According to C. W. Hayes ^ the bauxite of the Bryant district
in Saline County is a decomposition product, in place, of nepheline
syenite. The bauxite bed is described as resting directly upon a
kaoUnized type of the syenite (locally known as chimney rock), and
overlaid by Tertiary sands and gravels. The thickness of the bed
over a large part of the district is from 10 to 15 feet, though in places
reaching a maximum of 40 feet. Both the underlying kaolinized
TDck and the overlying Tertiary sands and gravels are more easily
eroded than the bauxite and hence the latter, where erosion is well
advanced, is apt to stand out in the form of a low ridge. Two
distinct types of ore are recognized in this district, (i) granitic and
(2) pisolitic. The first mentioned lies next to the kaolinized syenite,
is of a yellowish-gray color, a spongy structure and is quite free from
any trace of pisolites, showing, on the contrary, distinct traces of
of the crystalline ("granitic") structure of the original syenite,
in which the nepheline and orthoclase have been preserved only
in form of skeletons of alumina. Original cleavage surfaces of these
minerals can even at times be detected, though more frequently the
structure is quite obliterated. This type of ore occurs also in the
form of well-rounded boulders from 2 or 3 inches to 2 feet in diameter.
Such are surrounded by a dense structureless shell or crust from
i to j of an inch in thickness, but within which the material resumes
the normal, spongy form. Both portions have essentially the same
composition. The boulders were presumably simply waterwom
masses of the syenite. Dr. Hayes regards this form of the bauxite
as in every case derived directly from the syenite by the decomposi-
tion of the feldspar and nepheline (elaeolite), and the removal in
solution of the silica, lime and alkalies. The second class of ore
mentioned — the pisolitk; — forms the upper part of the bauxite bed,
' Twemy-first Annual Report, U.S. Geological Survey, 1899-1 900, Part. Ill, p. 446.
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9* THE NON-METALLIC MINERALS.
or sometimes constitutes the entire bed, resting directly upon tha
kaolin. There b a well-marked gradation in the character of the
ore from one part of the district. to another, the one sometimes pre-
vailing and sometimes the other.
The origin of the two types, as here associated, has not been
satisfactorily worked out, though possibly that of the pisolitic type
offers the fewest difficulties. After a discussion of the various
■ possibilities, Dr. Hayes sums up the matter as follows:
"The syenite of the bauxite region was intruded under a light
cover of Paleozoic rocks. These were subjected to rapid erosion
and the surface of the syenite was exposed. Either its subjacent
portions retained a considerable portion of their original heat, or a
fresh supply of heat was furnished by renewed intrusions or dynamic
disturbances. The region was then covered by a body of water
probably cut off from the sea, and salt, or highly alkaline. The
alkaline waters by some means gained access to the heated portbns
of the syenite and dissolved its minerals. The heated waters re-
turned to the surface heavily charged with the constituents of the
syenite in solution. They were still efficient solvents, however, and
acted upon the syenite at the surface, removing most of the silica,
along with the lime and the alkalies, but leaving the alumina and
depositing in place of the constituents removed about as much, or
more, alumina as the rock originally contained. Some of the alumina
brought to the surface in solution was deposited by this metasomatic
process, replacing a part of the silica removed from the syenite, but
a larger part was thrown down as a gelatinous precipitate on the
bottom of the water body and somewhat evenly distributed over
the undulating syenite surface, at the same time acquiring the piso-
litic structure and becoming mingled with the boulders of aluminized
syenite. Most of the spring exits were in the immediate vicinity
of the syenite areas, so that there the water was most strongly
impregnated with the various salts in solution and hence precipitation
of the alumina was most rapid. Wherever the ascending solutions
found their way to the surface by an isolated conduit through the
Tertiary sediment already deposited, a local deposit of greatw or
less extent was formed. The precipitation of the alumina must
have taken place almost immediately after the solution emerged
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OXIDES. 97
from the conduit, otherwise the bauxite would have been much
more widely disseminated, or even entirely dissipated in the sur-
rounding sediments."
As stated above, and as acknowledged by Dr. Hayes, this theory
is not altogether satisfactory, far less so, in fact, than that proposed
for the formation of the deposit in Georgia and Alabama. The
chief difficulty lies in the finding of a satisfactory solvent for the
original aluminous silicate and a cause for the rapid precipitation
of the alumina, when once in solution.
The Georgia and Alabama deposits, according to Hayes, are
found irregularly distributed within a narrow belt of country extending
from Adairsville, Georgia, southwestward, a distance of 60 miles,
to the vicinity of Jacksonville, Alabama, The only poin^ at which
it has been worked on a commercial scale are at Hermitage furnace,
i; miles north of Rome, Georgia, n:;ar Six Mile Station, south of
Rome, and in the dike district near Rock Run, Alabama. (See
Fig, 21.) The oldest rocks of the region are of Cambrian Age, and
are subdivided on lithologic grounds into two formations, the Rome
-sandstone below and the Connasauga shale above. The former
consists of 700 to 1,000 feet of thin-bedded purple, yellow, and white
sandstone and sandy shales. The Connasauga formation is between
2,000 and 3,000 feet in thickness. It consists at the base of fine
aluminous shales; the upper portbn is more calcareous, and locally
passes into heavy beds of blue seainy limestone.
Above the shale is the Knox dolomite. It consists of from 3,000
to 4,000 feet of gray, semicrystalline, siliceous dolomite. The silica
is usually segregated in nodules and beds of chert. These, in the
process of weathering, remain upon the surface, and with the other
insoluble constituents form a heavy, residual mantle a hundred feet
or more in thickness covering all the outcrops of the formation. It is
associated with these residual materials that the extensive deposits
of limonite and bauxite are foimd. The geological structure of the
region is complicated, and for its details the present reader is referred
to Dr. Hayes's original paper.
The bauxite deposits in the Rock Run district are regarded as
^ical for the entire region, and are described as follows:
Four bodies of the ore were being worked in 1893 on a con-
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9* THE NON-METALLIC MINERALS.
siderable scale, and all show practically the same form. The south-
ernmost of the four, called the Taylor bank, is located 3^ miles north-
east of Rock Run, near the western base of Indian Mountain. (See
Fig. 21}. .Mthough the heavy mantleof residual material effectually
conceals the underlying rocks, the ore appears to be exactly upon the
[Atler C. W. Hayea, U. S. Geological Survey.]
faulted contact between the narrow belt of Knox dolomite on the
northwest and the sandy shales and quartzites of Indian Mountain
on the southeast. It is covered by three or four feet of red sandy
clay, in which numerous fragments of quartzite are embedded. The
ore-body is an irregularly oval mass, about 40 by 80 feet in size. Its
contact with the surrounding residual clay, wherever it could be
observed, appears to be sharp and distinct, and, about the greater
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OXIDES. 99
portion of its circumference, very nearly vertical. A certain amount
of bedding is observable, although no trace can be detected in the
surrounding residual material. Upon the northwestern or down-
hill side of the ore-body this bedding is very 'distinct Layers of
differently colored and differently textured ore alternate in regular
beds, a few inches in thickness, and above these are thinner beds
of chocolate and red matmal, probably containing considerable
kaolin. These beds have a steep dip, somewhat greater than the
slope of the hillside, but in the same direction. They are not simply
inclined planes, however, but are curved, so as to form a steeply
pitching trough. With increasing distance from the ore-body the
UminatioD becomes less distinct, and the beds pass gradually into
Fig. as. — Sectionsboningtherelationof bauxite to mantle of residual clay ID Geotgia.
[After C. W. Hayes, U. S.Geological Survey.]
a homogeneous mottled clay. The accompanying section, Fig. 22,
shows these relations of the ore and residual mantle.
At the Dyke-bank (see Fig. 21), about a mile northeast of the one
above described, the stratification is well shown in portions of the
deposit. Beds of yellow and gray, fine-grained material alternate
with others of pisolitic ore. The beds dip at an angle of about 40,°
and are curved so as to form a steep trough. The compact material
also shows distinct cross-bedding, both primary and secondary planes
dipping in flie same direction.
In the Gain's Hill bank, about 250 yards north of the Dyke bank,
the ore-body shows a more regularly oval form than in most of the
other deposits, and is also somewhat dome-shaped, swelling out
laterally from the surface downward, as far as the working has pro-
Although spme of the workings have gone to a considerable depth
(in a few cases 50 feet or more), the bottom of the ore-body has
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lOO THE NON-METALUC MINERALS.
not been reached in any case. The ore varies in composition with
depth, but not in a uniform manner, nor more than do different
portions at the same depth. The deepest pits have not gone below
the base of the surrounding residual mantle, so that no observations
have yet been made with r^ard to the relations between the ore
and the country rock; and nothing has yet been observed which
warrants the conclusion that the ore, if followed to sufficient depth,
will be found interbedded with the underlying formations, or even
that it will be found occupying cavities in the limestone — although
the latter is quite possible.
Concerning the origin of these deposits it is stated tiiat no eruptive
rocks, either ancient or modem, are found in the vicinity, nor are there
any rocks in this region which, by weathering, could yield bauxite as
a residual product. Hence, any satisfactory explanation must give
the source from which the material was derived, the means by which
it was transported, and the process of its local accumulation.
The ore is associated with the Knox dolomite or with calcareous
sandy shales immediately overlying the dolomite. The Connasauga
formation, consist'ng of 2,000 feet or more of aluminous shales,
invariably underlies the dokimite at greater or less distance beneath
the ore-bearing regions, and is probably the source from which the
alumina was derived.
The region has been profoundly faulted. Undoubtedly the
dislocations of the strata generated a large amount of heat. The
fractures facilitated the circulation of water, and for considerable
periods the region was probably the seat of many thermal springs
which it is reasonable to suppose were the agents by which the
alumina salt was brought to the surface.
The oxygen contained in the meteoric waters percolating at great
depths through the fractured strata would readily oxidize the sul-
phides disseminated in the aluminous shales. Sulphates would thus
be formed, the most abundant of which was ferrous sulphate. Some
sulphate of aluminum must also have been formed, together with the
double sulphate of potassium and aluminum, especially in the absence
of sufficient potash to form alum with the whole.
In its passage from the underlying shales through several thou-
sand feet of dolomite the heated water would become h^bly charged
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with lime, in addition to the ferrous and aluminous salts already in
solution. But calcium carbonate reacts upon aluminum sulphate,
forming a gelatinous or flocculent precipitate which consbts of alu-
minum hydroxide and the basic sulphate. This reaction may have
taken place at great depth and the resulting flocculent precipitate
been brought to the surface in suspension. From analogy with
pisolitic sinter and travertine now forming, such conditions would
appear to be highly favorable for the production of the structures
actually found in the bauxite. The precipitate was apparendy
collected in globular masses by the motion of the ascending water,
and constant changes in position permitted these to be coated with
successive layers of more compact material. Finally, after having
received many such coatings, the pisolites were deposited on the bor-
ders of the basin, and the interstices filled by minute oolites formed
in a similar manner or by the flocculent precipitate itself. Slight
differences in the conditions prevailing in the several springs, such as
concentration and relative proportion of the various salts in solution,
also temperature and flow of the water, would fffoduce the variation
in the ch^acter of the ore observed at different points.
A small portion of the ferrous sulphate was oxidized and pre-
cipitated along with the bauxite, but the greater part was carried
some distance from the springs and slowly oxidized, forming the
widespread deposits of limonite in this region.
Pittman describes highly ferriferous bauxite covering several
square miles of territory in the Innverell and EmmaviUe districts
of New South Wales. The material occurs "capping small hills, and
in many cases surrounding points of eruption."
"It is clearly," he says, "of volcanic origin, and while in some
cases it appears to consist of volcanic ash, in others in may have been
derived from the decomposition of basalt in silu." The analyses
quoted show it to run from 30 to 60 per cent of alumina; 2 to 42
per cent of iron oxide; 6 to 33 per cent of water, and equally varying
proportions of silica and minor impurities.'
Uses. — The better-known use of bauxite is as an ore of alumi-
num, for which piurpose it lies beyond the scope of the present work.
I Mineral Resources of N. S. Wales, by E. F. Fittmao, 1901.
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loa THE NOfJ-METALUC MINERALS.
It may, however, be well to state that before the ajuminum can be
satisfactorily extracted the ore is purified by chemical processes.
The principal use aside from this is for the manufacture of alums
and other aluminum salts such as are used in baking powders and
dyes. It is believed that the mineral, owing to its highly refractive
qualities, will be utilized in the manufacture of fire-brick and cru-
cibles. An alumino-ferric cake, a by-product obtained in tlie puri-
fying process, is claimed as of value for sanitary and deodorizing
purposes. The price of the crude ore varies greatly, according to
purity. The average price for the past few years has been about
$5 a ton.
BIBLIOGRAPHY OF CRYOLITE AND BAUXITE.
Paul Quale. Account of the Cryolite of Greenland.
Annual Report of the Smithsonian Institution, iS66, p. 398.
M. H. COQUAND. Sur les Bauxites de la chatne des Alpines (Soucbes-du-Rh6ne) et
leur ftge gfologique.
Bulletin de la SociA£ G&logique de France, ad Ser., XXVIII, 1870-71, pp.
98-115.
Edwasd Nichoi^. An Aluminum Ore
Transactions of the Americ&n Institute of Mining Engineeia, XVI, 18S7, p. 905.
P. JOHNSTBUP. Sur le Gisement dc la Kiyolithe au Greenland.
Bulletin de la Sod^t* Miniralogie de France, II, 1888, p. 167.
M. AucE. Note sui la Bauxite, son origine, son Age et son importance g^ologique.
Bulletin dc la Soaiti G^logique de FVance, 3d Ser., XVI, 18S8, p. 345.
Stanislas Meunier. R6aponse a des observations de M. Aug£ et de M. A. de Gn»-
soune sur I'histoire de la Bauxite et des Minerals Sid^rolithiques.
Bulletin de la Soci#t# Gteloglque de France, 3d Ser., XVII, 1SS9, p, 64.
R. L. Faceakd. Aluminum.
Mineral Resources of the United States, 1891, p. 147.
Tbia paper contains numerous references to which the present ccMn[^let has
not had access..
Hbkrv McCalley. Bauxite.
The Mineral Industry, II, 1893, p. 57.
C. WiLLARD Hayes. The Geological Relations of the Southern Appalachian Bauxite
Deposits.
Transactions ot the American Institute of Minbg Engineers, XXIV, 1894, p. 343.
W. P. Blake. Alunogen and Bauxite of New Mexico.
Transactions of the American Institute of Mining Knginrrn, XXIV, 1894, p.
Fkamcis Laur. The Bauxites. A Study of a New Mineralogical Famfly.
Transactions of the American Institute of Mining Engineers, XXIV, 1S94,
jvGooi^lc
Fbahcis Laos. On Bauxite.
Minutes of tbe Proceedings of the Institute Civil Engineos, CXX, 1894-9;,
Pt. 2, p. 443.
J . C. Brahker. The Bauxite Deposits of Arkansas.
Tbe Journal of Geology, V, 1897, pp. 263-289.
Tros. Watsok. The Georgia Bauxite Depoaits; their Chemical Conatitutioa and
American Geologist, July, 1901, pp. 25-43.
4. DIASPORE.
This is a hydrous oxide of alutninum corresponding to the for-
mula A1,0„H,0, — alumina, 85 per cent; water, 15 per cent; hard-
ness, 6,5 to 7, It is a whitish, grayish sometimes brownish or
yellowish mineral, occurring in the form of thin flattened or acicular
crystals and also fohated, massive, and in thin plates or rarely stakc-
titic. It ii transparent to subtranslucent, and sometimes shows
violet-blue colors when looked at in one direction, or reddish-blue
or asparagus-green In others. Luster, vitreous or pearly.
Occurrence. — ^The mineral commonly occurs with corundum and
emery in dolomite and granular limestone or crystalline schists. In
the United States it occurs in lai^ plates in connection with the
emfery rock at Chester, Massachusetts.
Uses. — See under Gibbsite.
5. CmBSITE; EYDKAfiGnXTTE.
This is also, like diaspore, a hydrous oxide of aluminum, corre-
sponding to the formula A1^0„3H,0, = alumina, 65.4 per cent; water,
34.6 per cent. The mineral is of a whitish, grayish, or greenish
color, sometimes reddish through impurities, and occurs in flattened,
hex^onal crystals, or in stalactitic and mammillaiy and incrusting
surfaces. Its occurrence is similar to that of diaspore.
It has been shown that the so-called laterite of the Seyschellian
Islands in the Indian Ocean is a mixture of quartz, iron oxides and
hydrargyllite. Whether or not the last named is in such form as
to be of economic value is not yet apparent.
Uses. — Neither diaspore nor gibbsite have as yet been found
in sufficient quantities to be of economic importance. Should
they be So found, their value as a source of alumina is easily
apparent
ovGoO'^lc
THE NON-MBTMLUC MINERALS.
The term ocher as commonly used applies to earthy and pulveru-
lent forms of the minerals hematite and limonite, but which are al-
most invariably more or less impure through the presence of other
metallic oxides and ai^llaceous matter. In nature the material
rarely occurs in a suitable condition for immediate use, but needs
first to be prepared by washing and grinding, and perhaps roasting.
Various varietal names are applied to the ochers, according to
their natural colors or sources. The original " Indian red " was a
red argillaceous ocher, with a purplish tinge, found on the island
of Ormuz, in the Persian Gulf. A large part of the pigment of this
name is now prepared artificially from iron pyrites. Umber is a gray,
brown, or reddish variety containing manganese oxides and clay.
It derives its name from Umbria, in Italy, where material of this
nature was first utilized. Sienna is a highly argillaceous variety, also
from Italy, near Sienna.
The natural colors of the ochers are dependent on the degree of
hydration and oxidation of material and the kind and amount of
impurities. In a general way the hematites are of a deep red color,
while the limonites are yellow or brown. Either color is liable to
shade variations, according to amount and kind of impurities. The
colors are intensified, or otherwise varied, by roasting.
Artificial ochers are produced by roasting iron pyrites (sulphide
of iron) or an artificial sulphate \green vitriol). (See under Pyrite.)
The materials known commercially as rouge, crocus, and Indian red
are quite pure ferric oxide, prepared by roasting pyrite or by other
artificial means.
r OCHEKS IH THEIK KATUBAI, COKDmOH.
Light veUow. .
..Hucoc
!, Pwe Co., Virginii
. Bciks Co., Peni
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Light brown paint e
Blown-purple paint d
a. MxOe from nd [oanlilertnu om mined at Atalli
b. Uule bf IroD Clad Paint Company, of Clcvelaai
tew York.
Cm Prom on mined at Lake Superior, Michigan.
d. Ore tram Jackson Mine, Michigan.
A "blue ocher," formed by the decomposition of the Utica shales
in Lehigh County, Pennsylvania, has the following composition:
Coiutitusnta.
Ignition (water and carbon)
Quani
Combined ^lica
Alumina with traces of feiric oxide.
Magnesia
Alkalies, etc
A second variety, from ij miles northwest of Breinigsville, and
which was sold as a yellow ocher, yielded:
Silica, 60.53; alumina, 17.40; ferric oxide, 9.27; lime, 0.08;
magnesia, 1.92; water, 5.51; alkalies, 5.27.
Origin and mode 0} occurrence. — These vary greatly. In some
cases deposits of this nature are formed by springs. Such result
from the leaching out from the rocks, by carbonated waters, of iron
in the protoxide condition, and its subsequent deposition as a hy-
drated sesquioxide. In other cases they are residual products
formed by the removal, by solution, of the lime carbonates of cal-
careous rocks, leaving their insoluble residues — the clay and iron
oxides — in the form of a red, yellow, or brown ocherous clay. Again,
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io6 THE NON-METALLIC MINERALS.
they may result from the decomposition (oxidation) of beds of pyrite
(iron disulphide) and from the decomposition of beds of hematite,
and by the disintegration of the more compact forms of limonite.
Still again, they may resuh from the decomposition of schists and
other rocks rich in iiion-bearing silicate minerals. The yellow ochers
of the Little Catoctin Mountains, near Leesburg, Virginia, are thus
stated to be residual products from the decomposition of hydro-
mica or damourite schists.
An extensive deposit, or line of deposits, of yellow ocher near
Cartersville, Georgia, is described as occurring in the form of ex-
tremely irregularly branching veins intersecting a shattered quartzite
of Cambrian age. The veins often expand into bodies of consider-
able size, and when the ocher is removed, rooms 6 to lo feet in
diameter are sometimes left, connected by narrow, winding passages.
The contact between the ocher and quartzite is never sharp, but
there is a gradual transition from one to the other, " The quartzite
first becomes stained a light yellow and loses its compact, close-
grained texture. This phase passes into a second, in which the rock
is perceptibly porous, having a rough fracture and a harsh feel, and
containing enough ocher to soil the fingers. In the next phase the
ocher preponderates, but is held together by a mote or less con-
tinuous skeleton of silica, although it can be readily removed with a
pick. The final stage in the transition b the soft yellow ocher,
fillit^ the veins, which crumbles on drying, and contains only a small
proportion of silica in the form of sand grains," An examination with
the microscope seems to point unmistakably to an origin through
a chemical replacement of the silica of the ^quartzite by the iron
oxide, as has been shown by Van Hise to have taken place in .he
case of the hematite ores of the Lake Superior region. The chem-
btry of the process is not, however, quite clear. The rocks are
faulted, and may at some time have been permeated by heated
solutions. Water from the surface rocks containing in solution iron
carbonate or other ferrous salt, penetrating downward through the
shattered quartzite, would meet with oxidizing solutions, and the iron
would be precipitated as limonite, and in thb particular case in an
ocherous form. Thus far the reaction is not difficult to understand,
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OXIDES. 107
but to account for the removal of the silica is not so easy. The
heated solutions from below, perhaps alkaline, may have been instru-
mental in bringing it about, and perhaps also the carbonic acid
hberated during the process of oxidation.*
A paint ore found near Lehigh Gap, Carbon County, Pennsylva-
nia, though not properly an ocher, may be described here for want of
a better place. The raw material is a dull shaly or slaty rock,
of a dark gray color, sandy texture, and quite hard, and if descrip-
tions are correct is probably an arenaceous siderite or carbonate
of iron.
According to C. E. Hesse ' the paint bed is of unknown extent
except so far as indicated by outcrops along the southern border
of Carbon County, about 27 miles north of Bethlehem, where it
occurs in a well-defined ridge of Oriskany sandstone. Along the
outcrop the beds are covered by a cap of clay and by the decomposed
portion of the Marcellus slate. Beginning with this slate the meas-
ures occur in the following descending order:
a. Hydrauhc cement (probably Upper Helderberg), very hard
and compact.
b. Blue clay, about 6 inches thick.
c. Paint ore, varying from 6 inches to 6 feet in thickness.
d. Yellow clay, 6 feet thick.
e. Oriskany sandstone, forming the crest and southern side of
the ridge. It is extremely friable, and disintegrates so readily that
it is worked for sand at many points. (See Fig. 23.)
The paint bed is not continuous throughout its extent. It is
faulted at several places; sometimes it b pinched out to a few inches,
and again increases in width to 6 feet. The ore b bluish gray,
resembling limestone, and is very hard and compact. The bed is
of a lighter tint, however, in the upper than in the lower part,
and this is probably due to its containing more hydraulic cement
' Hayes and Eckel, Contributions to Economic Geology, Bulleljn No. 113, Series
A, Economic Geology, XXIV, U. S. Geological Survey, 1901, pp. 437-431. See also
Bullelia No. 13, Geological Survey of Georgia, 1906.
'Tiansactbns of the American Institute of Mining Engineers, XIX, 1891, p. 391.
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io8 THE NON-METALLIC MINERALS.
in the upper strata. The paint ore contains partings of clay and
slate at various places. At the Rutherford shaft there are five
bands of ore alternating
with clay and slate, as
follows: Sandstone (hang-
ing wall), clay, ore, slate,
ore, clay, ore, slate, ore,
cement, slate (foot wall).
These partings, however,
are not continuous, but
pinch out, leaving the ore
without the admixture of
clay and slate. Near the
outcrop the bed becomes
brown hematite, due to the
leaching out of the lime
and to complete oxidation.
Occasionallystreaks of hem-
atite are interleaved with
the paint ore. In driving
up the breasts toward the
outcrop the ore is found at
the top in rounded, partially
Fic.*3-— Section across the bed, Rutherford and oxidized, and weathered
Barclay Mine. „ , „, ,
[After c. E. Hesse.] masses, called "bomb-
shells," covered with iron
oxide and surrounded by a bluish clay. In large pieces the ore
shows a decided cleavage.
Some of the mines of Clinton iron ore (hematite) in New York
State, and the hematite ores of St. Lawrence County, are used in
paint manufacture, as are also ferruginous shales and slates. The
green, brown and blue shales occurring in the Chemung formation
in Cattaraugus County have thus been utilized as well as the red
shale occurring at the base of the Salina formation in Herkimer
Coimty. The utility of the material depends, naturally, upon the
amount of iron contained by it and the facility with which it can
be reduced to a gritless powder. Even the red roofing slates
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OXIDES. 109
of Washington County find a limited application along these
lines.
A mineral paint mined on Porter Creek, near Healdsburg,
Sonoma County, California, is said 1 to consist of hematite and
silicate of iron in the form of a compact mass lying between hom-
blendic rock, actinolite, and mica schist on the one side and rotten
serpeitine on the other. The vein has a north-of-east course, and
is some 60 feet in width. The material is mined from a tunnel,
crushed, ground between buhrstones, and bolted, making a paint
fit for mixing with oils or japan.
Preparation. — As already intimated, only a small portion of the
ocher is used in its natural condition, it being first roasted and then
ground, the grinding being either "dry" or in oil. The roasting
deepens the color to a degree dependent upon the length of time the
ore is exposed. Yellows are convened into browns and reds, and
the ocher rendered less hydrous at the same time. The crude ore
as mined is not infrequently separated from the coarser or heavier
impurities by a process of washing in running water, whereby the
ocher, in a state of suspension, is drawn off into vats, where it is
allowed to settle, the water decanted, and the sediment made up
into bricks and dried, when it is ready for grinding.
The method pursued at Caldbeck Falls, in Cumberland, Eng-
land, is as follows, the ocher occurring here in a vein in granite and
admixed with quartz: ^
"The umber is brought down by an overhead tramway and
passed through a hopper into a wash barrel consisting of a cylinder
formed of parallel bars one-eighth of an inch apart, having a perfo-
rated pipe conveying water, for its axis. By this means the umber
is washed through, the quartz being retained; the former then passes
to an edge-runner, the casing of which is of sufficient depth to allow
of the submersion of the rollers. The rate of revolution is about
14 to the minute, and the finer floating particles flow into the di^
mill. The bed of this mill is a single block of granite, and ovei it
' Twelfth Annual Report of the, State Minemlogist, 1894, p. 406.
' Journal of the Society of Chemical Industry, October, 1S90, p. 953.
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no THE NON-MET^LUC MINERALS.
the four buhrstone blocks are dragged; the finer 'floating' particles
of umber pass to a second mill of the same kind, then through a
brass wire sieve (to remove particles of peat and heather that have
been floating throughout the process) to settling tanks, composed of
brickwork lined with cement After settling for four hours four-
fifths of the water is drawn off, and the umber, now of the con-
sistency pf slurry, filter-pressed and dried. It has the following
composition :
CoMliluenhi.
Per Cent.
«-14
11
Trace
Trace
34.70
6. is
siii^ :;:::::::;::::;;:::
100.08
In diis form it is put upon the market.
At the Lehigh Gap Mines the ore, as it comes from the mines,
is free from refuse, great care having been taken to separate slate
and clay from it in the working places. It is hauled in wagons to
kilns, which are situated on a hillside for convenience in charging.
The platform upon which the ore is dumped is built from the top of
the kiln to the side of the hill. The ore is first spalled to fist size
and freed from slate, and is then carried in buggies to the charging
hole of the kiln.
The kiln works continuously, calcined ore being withdrawn and
fresh charges made without interruption. The ore is subjected for
forty-eight hours to the heat, which expels the moisture, sulphur,
and carbon dioxide. About ij tons of calcined ore are withdrawn
every three hours during the day. The outside of the lumps of
calcined ore has a light-brown color, while the interior shows upon
fracture a darker brown. Great care is necessary to regulate the
heat so that the ore is not overbumt. When this happens the
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product has a black, scoriaceous appearance, and is unfit for
the manufacture of metallic paint, as it is extremely hard to
grind.
The calcined ore is carried from the kiln in wagons to the mill,
where it is broken to the size of grains of com in a rotating crusher.
The broken ore is carried by elevators to the stock bins at the top
of the building, and thence by shutes to the hopper of the mills, which
grind it to the necessary d^ree of fineness. Elevators again carry
it to the packing machine by a spout, and it is packed into barrels
holding 500, 300, or loo pounds each.
Uses. — ^The ochers are among the most widespread and readily
accessible of coloring materials, and have been used by savage and
civilized people, both ancient and modem. The war paint of the
American Indian was not infrequendy an ocher mixed with oil or
grease. According to William J. Russell,^ the pigments used by the
Egyptians and others since the earliest times were of hematite, and
mostly of an odhtic variety, apparently closely corresponding to
the Clinton hematites of New York State. As tested, such were
found to contain from 79.11 to 81.34 per cent ferric oxide.
The ochers are now used mainly in the manufacture of paints for
exteriors, as of buildings, the rolling stock of railways, bridges, and
metal roofing. They are also used as a pigment for coloring mor-
tars, and in the manufacture of linoleums and oilcloths. Mixed
with a certain proportion of oxide of manganese, the ochers have
been used to produce desirable colors in earthenware. The Cald-
beck Falls material noted is said to be utilized, in addidon to the pur-
poses mentioned, for the coloring of various kinds of brown paper.
The raw ocher (that is, ocher not roasted), of a light-yellow color,
was at one time in great demand, particularly throughout New
England, for painting floors.
The value of the prepared material is but a few cents a pound.
> Nature, XUX, 1894, P- 374-
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"a THE NON-MET^LUC MINERALS.
BIBLIOGRAPHY.
Funk A. Hill. Report on the MetalUc Paint Ores along the Lehigh River.
Annua) Report, Pennsylvania Geological Survey, 1S86, Tt. 4, pp. 1386-1408.
This is an important paper, givii^ posjtioa of ore beds, methods of mining
and manufacture.
Conrad E. Hesse. The Paint Ore Mines at Lehigh Gap.
Transactiooi of the American Institute of Mining Engineeis, XIX, 1890, p. 311.
C. W. Haves and E. C. Eckel. Occunence and Development of Ocher Deposits
in the Caiteisville District, Georgia.
Bulletin No. 313, Series A, Economic Geology, XXIV, U, S. Geol. Survey,
7. ilhentte; uenaccanite ; or titanic iron.
Composition. — FeTiO,, = oxygen, 31.6 per cent; titanium, 31.6
per cent; iron, 36,8 per cent; hardness, 5 to 6; specific gravity, 4.5
to 5; color, iron-black with a submetallic luster and streak; opaque.
Differs from magnetite, which it somewhat resembles, by its crys-
talline fonii and by its influencing but slightly the magnetic
needle.
Mode 0} occurrence, — Its common form is massive, or in thin plates
or laminae, or as small granules, sometimes disseminated through
the mass of rock or loose in the sand. In microscopic forms it is
a common constituent of eruptive rocks, both acid and basic. Not
infrequently it occurs in large masses, closely resembling magnetic
iron ore. In the parish of St. Urbian, Bay St. Paul, Province of
Quebec, Canada, is such a bed, stated to be 90 feet in thickness and
to have been traced, with some interruptions, for a mile. The bed
is in anorthite feldspar rock of Laurentian age. The ore is quite
pure, and carries some 48.6 per cent titanic acid. At Kragero, in
Norway, the mineral occurs in the form of veins in diorite. In
Virginia it is found in granular masses, containing apatite.
Uses, — The mineral has as yet proved of little economic impor-
tance. It is stated that the presence of titanium has an important
bearing upon the qualities of iron and steel, but as such it is beyond
the scope of this work. As long -qgo as 1846 an attempt was made
to use a ferrocyanide of titanium as a green paint in place of the
poisonous arsenical greens. Later (1861) other patents were granted
in England for titanium pigments. A deep-blue enamel, resembling
the smalt prepared with the oxide of cobalt, has also been prepared
ov Google
from it, but as yet the mineral, though abundant and cheap, has
practically no economic use. In the course of time it will probably
be utilized in the manufacture of titanium steel.
8. RUTILE.
Composition and general properties. —This mineral is a titanium
oxide, having the formula Ti02,='Oxygen, 40 per cent, and titanium,
60 per cent The hardness is 6 to 6.5; specific gravity, 4.18 to 4.25;
luster, metallic adamantine, opaque as a rule, rarely transparent;
cotor, reddbh brown to red, rarely yellowbh, blue, or black; streak,
pale brown. The mineral crystallizes in the tetragonal system,
and is commonly found in prismatic forms longitudinally striated,
and often in geniculate or knee-shaped twins. Not infrequently it
occurs in the form of fine thread-like or ackular crystals penetrating
quartz. It b insoluble in acids and infusible before the blowpipe.
Brookite and octahedrite have the same composition and essen-
tially the same physical properties and mode of occurrence.
Mode of occurrence. — Rutile occurs mainly in the older crystalline
granitic rocks, schists, and gneisses, but is also foimd in metamorphic
limestones and dolomites, sometimes in the mass of the rock itself,
or in the quartz of veins. Being so nearly indestructible under nat-
ural conditions, it gradually accumulates in the d^ris resulting
from rock decomposition, and is hence not an unconunon constit-
uent of auriferous sands.
Localities. — Some of the better-known localities are the apatite
deposits of KragerS, in Norway; Yrieux, near Limoges, in France;
the Ural Mountains; and the Appalachian r^ions of the United
States. Graves Mountain, Georgia; Randolph County, Alabama,
and the Magnet Cove region of Arkansas are celebrated localities.
Near Roseland, Nelson Comity, Virgima, rutile is found dissemi-
nated a coarsely crystalline quartz feldspathic rock of evident igneous
origin. The mineral occurs mainly in the form of small granules
of all sizes up to 2 or 3 millimeters in diameter, which are sometimes
disseminated with remarkable uniformity throughout the feld-
spathic ground-mass or again segregated in the quartz; rarely pieces
of several pounds' weight have been found loose in the soil. The
rock is remarkably free from other minerak than those mentioned.
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114 THE NON-METALLIC MINERALS.
and there is a complete absence of titaniferous iron or heavy con-
stituents such as would render -difficult a separation of the rutil^ by
the ordinary gravimetric methods.
The ore is mined from open cuts, stamped and concentrated on
the premises, the yield varying from 5 to 25 per cent of rutUe concen-
trates in the form of a beautiful resinous red-brown sand.
Uses. — Much attention has of late been paid by metallurgists to the
question of the influence of titanium on cast iron and steel. The
consensus of opinion at date of writing is apparently to the effect
that such is beneflciaL According to A. J. Rossi cast iron may be
improved in both transverse and tensile strength from 20 to 30 per
cent by the addition of small amounts of titaniferous alloys. Quite
similar results follow its use in steel. Small amounts of titanium
are also used in the manufacture of artificial teeth and of porcelain
ware, in both cases serving as a pigment. It b also used in dyeing
leathers and in the preparation of the "carbons" used m electric
lights.
Until the establishment of the mill at Roseland, Virginia, some
200 to 300 pounds only of rutile were annually produced in the
United States, and 40,000 to 90,000 poimds in Norway, the average
value being about 10 cents per pound. The Virginia works are
capable of producing from 1,000 to 2,000 poimds per day.
BIBUOGRAPHY.
G. F. Mebbill. Rutile Mining in Virginia.
Engineeiing and Minii^ Journal, March S, igoi.
Thos. Waison. Mineral Resources of Virginia.
9. CHROHITE.
Chromite is a mineral of the spinel group, and of the theoretical
formula FeO,Cra03. This equals a percentage of chromic oxide
of 68 per cent, but the natural mineral has often alumina and ferric
iron replacing a part of the chromium, so that 50 per cent chromic
oxide more nearly represents the general average. The ordinary
demand, it may be stated, is for an ore carrying 45 per cent and
upward of chromic acid.
The analyses given on the next page will serve to show the vary-
ing character of the mino-al.
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Ii6 THE NON-METALUC MINERALS.
Chromite, like magnetic iron, is black in color and of a metallic
luster, but differs in being less readily if at all attracted by the ma^et
On a piece of ground glass or white unglazed porcelain it leaves a
brown mark, and fused with borax before the blowpipe it gives a
green bead.
Occurrence and origin. — Chromite is a common constituent in the ,
form of disseminated granules of basic eruptive rocks belonging to
the peridotite and pyroxenite groups and in the serpentinous and
talcose rocks which result from their alteration. It is never found in
true veins or beds, though sometimes in segregated, nodular masses
somewhat simulating veins on casual inspection. The more common
form, as noted above, is that of small masses and detached granules,
which, when freed from the inclosing rock, form the ore known as
chrome sand.
It is stated by J. H. Pratt, that in North Carolina chromite occurs
wider conditions very similar to those of corundum, ie., at and near
the line of contact between the intrusive peridotites and gneissk
rocks. It is thought probable by Pratt that the mineral was held
in solution in the molten magma at the time of its intrusion into the
country rock. Such a magma, he states ^ would be like a saturated
liquid, and as it began to cool the minerals would crystallize, not
according to their fusibility, but according to their solubility in the
molten material. The more basic minerals (in this case chromite)
being, according to the general law of cooling and crystallizing magmas,
the least soluble, would be the first to separate out. These early
crystallizations woiUd naturally take place near the line of contact
of the eruptive material with the previously solidified rocks, since
cooling would be here first manifested. Convection currents would
tend to bring new supplies of material and hence the deposits would
become enriched. F. Cirkel " reports a wide variation m the char-
acter of the deposits in Canada, no two being alike. In some cases
the ore occurs in disseminated granules and in others in lenses or
pocket-shaped deposits as knolls or kidney-shaped accumulations,
distributed through cracks in solid serpentine, or s^egated and in
contact with intrusions of granitic rock. This author, however,
' Transactions of ihe .\m. Inst, of Mining Engineers, XXIX, 1S99 ( 1900), p. 35.
' Report on Chrome Iron Ore Deposits in the Eastern Townships of Quebec.
Ottawa, 1909.
jvGooi^lc
— Segregalion Veins of Chrome Iron, near Rustenburg, South Africa.
[From Trans. Geological Society of South Africa.]
Fig. a. — Open Cut Manganese Mine, Crimora, Virginia.
[After Thos. Walson, Mineral Resources of Virginia.]
PLATE IX.
[Facing page itfi.]
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OXIDES. 117
finds nothing to support an oft-repeated assertion to the effect that
all of the commercially important deposits lie along the contact
of the serpentine with the granite or other rocks; in fact, some of
the larger deposits axe far removed from such contacts.
In the Transvaal, South Africa, the deposits occur associated
with igneous rocks rich in hypersthene and poor in plagioclase feld-
spars. They occur in what are described as fairly well-defined
bedded veins with dip and strike roughly analogous to that of the
neighboring sedimentary beds, the thickness of the veins varying
from 5 feet downward, and usual'y maintaining a fairly uniform
width for some distance. The following section is given showing
the occurrence at Mooihoek :
Pt.Ia.
I. Flne-gcsined fikble weaihered dark greenish noritic rock, rich in rhombic
pyrocene with scattered chiomite grains o o
3. Chrome iron vein composed of dark almost black granular ore t o
3. Fine-grained granular dirty greenish hypersthenite a 4
4. Black finegrained friable granukir chrome-iron ore nilh small lighter-cobred
in^;ular patches 4 6
5. Dark granular slightly giecriish byper^tbenite identical with No. 3 a 6
6. Vein of black powdery chtome-iron ore closely resembling No. 4 4 6
7. Granular hypersthenite with scattered grains of chroniite.
It tvill (b.us be seen that there are three separate sheets of the
chrome ore with a collective thickness of about lo feet. The presence
in the country rock of scattered grains of chromite shows, however,
that the deposits are not in true veins, but evidently segregations out
of the molten magma, as in Canada and North Carolina. In all of
these cases it is evident that the chromite deposits are to be considered
as original and not due to the alteration of the peridotite into serpen-
tine. Baumgartel,' it is true,describessecondarychromites origin-'t-
ing through the decomposition of chromiferous diopsides in Bosnian
peridotites, but there is nothing to show that such secondary deposits
ever occur of such magnitude as to be of commercial importance.
The principal domestic solutes of chromium are at present Del
Norte, San Luis Obispo, Shasta and Placer counties m California,
though formerly mines in Lancaster County, Pennsylvania, and
the Bare Hills re^on near Baltimore were very productive. The
American supply of material is to-day derived very largely from
Canadian sources, the distribution of the mines being coincident
' Tschermak's Min. u. Petr. Mitthdl., XXIII, 1904, p. 393.
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ii8 THE NON-METALUC MINERALS.
with that of the Cambrian serpentines, from which is derived the
asbestos and which occur in a belt extending from Southern Vermont
to Gaspe in the Province of Quebec. Along the course of this belt
chromite exists at several points, and many attempts have been
made at mining, but in most instances the mineral has been found
in too small a quantity to be of commercial value. The most im-
portant field is in what is known as the Thetford Black Lake area,
and especially in the township of Coleraine. The deposits are of
an exceedingly irregular character, having no definite form and no
tendency to adhere to dimensions in special directions and apparently
have no relation to each other. Masses of ore have been found
varying up to 50 or 75 feet in greatest diameter.
On account of the irregular character of the deposits there has
always been, and presumably always will be a considerable amount
of uncertainty in mining and little dependence can be placed upon
surface indications. The quality of ore that can be worked to com-
mercial advantage is naturally wklely variable, Cirkel states that
in the Canadian area a rock must yield at least 20 per cent of
chromite in order to be utilized.
Chrome ore is also found in Newfoundland; the Russian Urals;
in Asia Minor and European Turkey, and in Macedonia; in Aus-
tralia, New Zealand and New Caledonia, in all cases so far as known
the deposits occurring in peridotite or serpentine.
Uses. — Chromium is used in the production of the pigments
chrome-yellow, orange, and green, and in the manufacture of bichro-
mate of potash for calico printing and certain forms of electric bat-
teries, A small amount is also used in the production of what is
known as chrome steel.
Chrome-ore linings for reverberatory furnaces have been suc-
cessfully adopted in French, German, and Russian steel works.
The bottom and walls of the furnace are lined with the ore in lai^e
blocks, united by a cement formed by two parts of ore finely groimd,
and one part of lime as free from silica as possible.
The best composition used for lining reverberatory furnaces is
found to be from 36 to 40 per cent of chromic oxide, 18 to az per cent
of clay, 9 to 10 per cent of magnesia, and at most 5 per cent of silica.'
■ Journal of the Iron and Steel Institute, 1S95, pp. 506, 507. Abstract from L'Echo
des Mines, XXI, p. 584.
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OXIDES. 119
Chrotnite has be«i also successfully used as a hearth-lining for
copper-smelting purfx>ses.
"The chrome industry in America originated in the discovery
in 1827 of chrome ore in the so-pentine of the Bare Hills region,
some 6 miles north of Baltimore, Maryland. Mr, Isaac Tyson, Jr.,
began the manufacture of 'chrome-yellow' from this material in
Baltimore, in 1828. Finding that the chrome ore was always con-
fined to serpentine, Mr. Tyson began a systematic examination of the
serpentine areas of Maryland, which could be easily traced by the
barren character of the soil which they produce. A narrow belt of
serpentine extends across Montgomery County, and while chrome
ore is occasionally found in it, nothing of economic importance has
ever been discovered in Maryland south of the areas known as
'Soldiers' Delight' and 'Bare Hills.' Northeastward, however, the
deposits become much richer. The region near Jarrettsville was
productive, and thence the serpentine was traced to the State line
in Cecil County. Near Rock Springs the serpentine turns and
follows the State line eastward for 15 miles. On the Wood farm,
half a mile north of the State line and 5 miles north of Rising Sun,
in Cecil County, Mr, Tyson discovered in 1833 a chromite deposit,
which proved to be the richest ever found in America. This prop-
erty was at once purchased and the mine opened. At the surface
it was 30 feet long and 6 feet wide, and the ore so pure fliat each
10 cubic feet produced a ton of chrome ore, averaging 54 per cent
of chrome oxide. The ore was hauled 12 miles by wagon to Port
Deposit, and shipped thence by water to Baltimore and Liverpool.
At a depth of 20 feet the vein narrowed somewhat, but immediatdy
broadened out ^ain to a length of 120 feet and a width of from
10 to 30 feet. The Wood Mine was worked almost continuously
from 1828 to 1881, except between the years 1868 and 1873. During
that time it produced over 100,000 tons of ore and reached a depth
of 600 feet.
" Between 1828 and 1850 Baltimore supplied most of the chrome
ore consumed by the world; the remainder came from the serpen-
tine deposits and platinum washings of the Urals, The ore was at
first shipped to England. After 1850 the foreign demand for Balti-
more ore declined gradually till i860, since which time almost none
has been shipped abroad. The reason for this was the discovery in
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I20 THE NON-MET^LUC MINERALS.
1848 of great deposits of chromite near Brusa, 57 miles southwest of
Constantinople, by Professor J. Lawrence Smith, who was employed
by the Turkish Government to examine the mineral resources of
that country. Other deposits were also discovered by him 15 miles
farther south, and near Antioch."
Between iSSo and 1892 the annual production of chromite in the
United States varied between 1,500 and 3,000 tons. During the
succeeding decade the production was gready diminished. Statistics
for 1908 show an output, wholly from California, of but 280 long
tons, valued at about $20.00 per ton. Some 7,876 tons were im-
ported during this same year. The principal sources of supply
are now Canada, Greece, New Caledonia, New South Wales, Russia
and Turkey. The Canadian output during 190S is placed at 7,225
tons.
BIBLIOGRAPHY.
Lake Chrome and Mineral Company, of Baltimore County.
Amerian Mineral Gazette and Geological Magazine, I, April i, 1664, p. 153.
Harrie Wood. Chromite and Manganese.
Mineral Products of New South Wales, Department of Mines, 18S7, p. 4a.
L'eber schwedisches Chroiiiroheisen und Maitinchromslabt.
Berg- und Hill ten mAnniache Zeitung, XLVII, 188S, p. 167.
Die Chromeisenerz-lAgecsUUlen Ncuseelaods.
Berg- und HilttenmS.nni5che Zeitung, XLVII, 1S8S, p. 375.
Chromite Mined at Cedar Mountain.
Eighth Annual Report of the Slate Mineralogist of California, 18SS, p. 37.
Chrome Iron Ore from Orsova.
Journal of the Iron and Steel Institute, i38q, p. 316.
Chrome Iron in Shasta and San Luis Obispo Counties.
Tenth Annual Report of the Stale Mineralogist of California, 1S90, pp. 583
and 63S.
Chrome Iron.
Twelfth and Thirteenth Reports of the State Mineralogist of California,
1S94 and 1896.
Chromic Iioti: Its Properties, Mode of Occuirenn, and U«eL
Jountal of the General Mining Assoication of the Province of Quebec, 1894-95,
p. loS.
W. F. Wilkinson. Chrome Iron Ore Mining in Asia Minor.
Engineering and Mining Journal, LX, 1895, p. 4.
Wh. Glenn. Chrome in the Southern Appalachian Region.
Transactions of the American Institute of Mining Engineers, XXV, 1895,
p. 481.
Gkoxgk W. Maynabd. The Chromite Deposits on Port au Port Bay, New Found-
land.
Transactions <A the American Insthute of Mining Engineers, XXVII, 1S97,
p. 383.
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J, H. Pbatt. The Occurrence, Origin, and Chemical Composition of Cliromitc, with
especial reference to the North Carolina Deposits.
Transaclions of the American Institute of Mining Engineers, XXfX, 1899,
F. CtsKEL. Report on Chrome Iron Ore Deposits i:
of Quebec, Ottawa, 1909.
Eastern Townships. Province
10. MANGANESE OXIDES.
The element manganese exists in nature under many different
forms, of which those in combination as oxides, carbonates, and
silicates alone need concern us in this work. The principaf known
oxides are Manganosite (MnO) ; Hausmannite (MnO,Mn,0,) ;
BraimiteC3Mn,0„MnSiO,); Polianite (MnO,) ; Pyrolusite (MnO,);
Mai^anite (Mn,O^H,0); Palomelane (H^MnO,); and Wad, the
last being, perhaps, an earthy impure form of psilomelane. To this
list should be added the mineral franklinite, a manganiferous oxide
of iron and zinc. Of these, the first named, manganosite, b rare,
having thus far been reported only in small quantities associated
with other oxides in Wermland, Sweden. The other forms are
described somewhat in detail as below. It should be stated, how-
ever, that with the exception of the well-crystallized forms it is
often difficult to discriminate between them, as they occur admixed
in all proportions, and, moreover, one variety, as pyrolusite, may
result from the alteration of another (manganite). The better defined
sf)ecies may be separated from one another by their comparative
hardness, streak, and hydrous or anhydrous properties, as shown
in the accompanying table.
Variety.
^^l
Color.
Stnak.
t^^Z
i 11
4.3 4.«
Reddish brown to
black
Chtttnut-browo, . . , .
Brown-black
Black
Black or blue-black.
Red-brown to black..
Brown- black.
Bnuiniu
Bmwn-bUcIt
Brown-black to ateeU
Anb^drou.
PoKiuiite
PyroluHle
a Do.
Hydro™.
Do.
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THE NON-METALLIC MINERALS.
The chemical relationship of the ores as found in nature is thus
set forth by Penrose : '
Proloiide (MnO)
Proto-sesquioxide (Mn,0,)
Sesquioxidc (MiijO,)
Peroxide (MnO^
(MnO) . .
(Mn,OJ .
Btaunite (Mn,Oj)
Fyroluute, Polianite (MnO,)
Pyrochroite <MnO.H,0).
Manganile (Mi.,0„H,0).
iPslomelane.
Wad.
Manganese oxides frequently occur admixed in indefinite pro-
portions with the hydrous oxide of iron, Umonite, giving rise to the
manganiferous limonites.
Franklinite. — This may be termed rather a manganiferous
ore of iron and zinc than a true ore of manganese. Nevertheless,
as the residue after the extraction of the zinc is used in the manu-
facture of spiegeleisen, we may briefly refer to it here. The mineral
occurs in rounded granules or octahedral crystals of a metallic
luster and iron-black color, associated with zinc oxides and silicates
in crystalline limestones, at Franklin Furnace, New Jersey. It bears
a general resemblance to the jnineral magnetite, but is less readily
attracted by the magnet and gives a strong manganese reaction-
Its average content of manganese oxides Mii,0, and MnO is but from
15 to 20 per cent.
Hausmamiite. — This form of the ore when crystallized usually
takes the form of the octahedron, and may be readily mistaken for
franklinite, from which, however, it differs in its inferior hardness,
lower specific gravity, and in being imacted upon by the magnet.
It occurs in porphyry, associated with other manganese ores, in
Thuringia; is also found in the Harz Mountains; Wermland,
Sweden, and various other European localities. In the United
States it is reported as occurring only in Iron County, Missouri.
The mineral in its ideal purity consists of sesquioxide and protoxide
of manganese in the proportion of 69 parts of the former to 31 of
the latter. Analyses of the commercial article as mined are not
at hand.
Braunite. — This, like hausmannite, crystallizes in the form of the
octahedron, but is a trifle harder. Chemically it differs, in that
analyses show almo.<^t invariably from 7 to 10 per cent of silica,
'Annual Report of the Geological Survey of Arkansas,!, 1890, p. 541.
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though as to whether or no this is to be considered an essential
constituent it is as yet difficult to say. Analyses I and II, on p 124,
show the composition of the mineral as found. The ore is reported
as occurring both crystallized and massive in veins traversing por-
phyry at Ochrcnstock in Ilmcnau, in Thuringia, near Defeld in the
Harz; Schneeberg, Saxony, and various other European localities.
Also at Vizianagram in India; in New South Wales, Australia, and
in the Batcsville region, Arkansas.
PoUatlite. — Like pyrolusite, yet to be noted, this form of the ore
is chemically a pure manganese binoxide, carrying some 63.1 per
cent metallic mai^anese combined with 36.9 per cent oxygen. From
pyrolusite it is readily distinguished by its increased hardness.
So far as reported, it is a rather rare form of manganese, though
possibly much that has been set down as pyrolusite may be in
reality polianite.
Pyrolusite occurs in the form of iron-black to steel-gray, some-
times bluish opaque masses, granular, or commonly in divergent
columnar aggregates sufficiently soft to soil the fingers, and in this
respect easily separated from the other common forms excepting wad ;
not known in crystals except as pseudomorphs after manganite.
In composition it is quite variable, usually containing traces of iron,
silica, and lime, and sometimes barium and the alkalies. Analyses
III and IV, on p. 124; as given by Penrose, will serve to show the
general average. This is a common ore of manganese, and is
extensively mined in Thuringia, Moravia, Bohemia, Westphalia,
Transylvania, Australia, Japan, India, New Brunswick, Nova
Scotia, and various parts of the United States.
Hai^;aiiite differs and is readily distinguishable from the other
ores thus far described, in carrying from 3 to 10 p>er cent of com-
bined water, which can readily be detected when the powdered
mineral is heated in a closed tube. From cither psilomelane or
pyrolusite it is distinguished by its hardness. \Vhen in crystals it
takes prismatic forms with the prism faces deeply striated longi-
tudinally. Its occurrence is essentially the same as that of
braunite.
Psilomelane. — This is, with the possible exception of pjTolusite,
the commonest of the manganese minerals. The usual form of
occurrence is that of irregular nodular or botryoidal masses em-
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134 THE NON-METALLIC MINERALS.
bedded in residual clays. It is readily distinguished from manganite
or wad by its hardness, and from hausmannite. braunite, or polianite
by yielding an abundance of water when heated in a closed tube.
The sample from the Crimora Mines in Virginia, shown in Plate X,
is characteristic. The composition of the commercial ore is given
in analyses V, VI, and VII, below.
Wad or Bog Manganese is a soft and highly hydrated form
of the ore, as a rule of little value, owing to impurities (analysis VIII).
Asbolite is the name given to a variety of wad containing cobalt (see
p. aS). See further Rhodonite and Rhodochrosite, pp. 159, 304.
ANALYSES at HANOAHESE ORES
BniuDite.
Pyroiusita.
P>ilQme!«n*.
W«l.
I.
II.
III.
IV
V
VI
VII
VllI
8747
1%
90-15
88.98
S3
«o.,
63^6
600
354a
3'SS
o-«
0.18
IIS
0-95
3 OS
H.d .:.::::::;:;:
33 SI
II- Bl^eraburff Germuiy.
III. Chcvcrii Novk ScotiA.
IV. Cape Breton.
VI SchnMbcTS Sutony
VII Cnmo-i Virgiiui
VIII. Bic Hmrbor Cape Bre
Origin. — ^The deposits of manganese oxides which are of sufhdent
extent to be of conmiercial importance are believed to be in all cases
of secondary origin; that is, to have resulted from the decompo-
sition of preexisting manganiferous sihcate constituents of the older
crystaUine rocks and the subsequent deposition of the oxides in
secondary strata. Indeed in many instances the ore has undergone
a natural segregation, owing to the decomposition of the parent
rock and the accumulate of the manganese oxide, together with
other difficult soluble constituents in the residual clay. Thus Penrose
has shown' that the deposits of the Batesville (Arkansas) region
result from the decay of the St Clai' limestone, the various stages
of which are illustrated in the accompanying Plate XI. The fresh
' Annual Repoil of Ihe Geological Survev of Arkansas. I. 1890.
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6 =
an;;-!
11-
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limestone) as shown by analysis, contains but 4.30 per cent manga-
nese oxide (MnO), while the residual clay left through its decom-
position contains 14.98 per cent of the same constituent.
Occurrence. — As above noted, the ore is found in secondary rocks,
iind as a rule in greatest quantities in the clays and residual deposits
resulting from their breaking down. The usual form of the ore is
that of lenticular masses or irregular nodules distributed along the
bedding planes, or heterogeneously throughout the clay. Penrose
describes the Batesville ores as sometimes evenly distributed through-
out a large body of clay, but in most places as being in pockets sur-
rounded by clay itself barren of ore. These pockets vary greatly in
character, being sometimes comparatively solid bodies separated by
thin films of clay, and containing from 50 to 500 tons of ore; some-
times they consist of lai^e and small masses of ore embedded together,
and ogam at other times of small grains, disseminated throughout
the clay. In the Crimora (Virginia) deposits the ore (psilomelane)
is found in nodular masses in a clay resulting from the decomposi-
tion of a shale which has been preserved from erosion through sharp
synclinal folds.
The position and association of these deposits may be best
understood by reference to the accompanying figures,' Fig. 24 being
that of the ground plan of the immediate vicinity of the mine, while
F^. 25 represents cross-sections along the lines marked in Fig. 24.
The country rock is a massive Potsdam sandstone overlaid by shales,
the latter having undergone extensive decomposition, giving rise to
clay deposits in which the ore now occurs. At the east, along the
line AA in Fig. 24, the sandstone dips to the westward. At CC is
an anticline from which the beds dip both toward the west and east,
forming thus a syncline the axis of which is indicated by the Ime BB.
The sections across this syncline (Fig. 25) show the accumulated
clay from the decomposition of the shales, in which the man-
ganese occurs. The ore is found very irregularly distributed
throughout the clay in lumps and masses from the size of a small
pebble to those weighing a ton or more. The basin is described
t From Geological Notes od the Manganese Ore Deposit of CTimora, Virginia.
By Charles E. Hall, Trans. Am. tnst. of Min. Engs., VoL XX, iSgt, pp. 47, 48.
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THE NQN-METALUC MINERALS.
SECTION No. 1
SECTION No. 4
FlQ. 15. — Sections through Crimora manguiese
[After C. E. HaU.]
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iAL Sections SHOwrHC the formation of MAHSAHESE-SEARiNe
CLAY FROM THE DECAY OF THE S T.Ct AIR UME STONE.
Bmwc Cheit [^MANStMSC<BeM>HaCL*''E3lZAnDLlnEaTMte
ST.CLAIR UMOTOHC LOS*0CttMOI0»l.S»«0»TW«
Fia.1. ofnaiNAL ooMnnoN orxHE f?ocK9.
FI8.2. FIRST STAOE OF DECOMPOSITION.
FILS. lecOND 8TACC OF DEC0r*>O9mON .
FK:.4. THIRD STAU OF DECOMPOSnWM.
. PLATE XI.
li Sections to Show Olgir of Manganese through Weathering of Limestone.
' [Aflu PennMC, Ann, Kep. Geol. Survey of Arkansas, Vol. I, 1892.]
[Facing page 116.]^^ |^
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OXIDES. I a?
as some 500 feet in width and 800 to 900 feet in length, the ore-bearing
day extending to a mairimnm depth, so far as determined, of 300
feet.
The manganese appears to have been here originally disseminated
throughout the sandstone and shales and to have leached out, pre-
sumably as a carbonate, by percolating water, and redepo^ted in
the basin, where the flow was retarded for a sufficient time for oxida-
tion to take place.
In Cuba, maganese is found in the province of Santiago, the
principal occurrence being in a belt lying back of the Sierra Maestra
and extending from the vicinity of Guantanamo upon the east to
Manzanillo upon the west The ore, which may be either manganite,
pyrolusite, or wad, singly or all together, occurs as a rule upon hills
or knolls composed of sedimentary rocks — sandstones and lime-
stones— in disconnected or pocket deposits and under such con-
ditions as to point unmistakably to an origin through the influence
of circulating waters. The ore is often associated with a hard
jasper, or "bayate," occurring in large masses, or in the form of
disseminated nodules or veinlets in the ore. The occurrence and
association are such as to indicate that the two substances were
deposited nearly contemporaneously, and from the water of hot
springs.
Branner has described the maganese (psilomelane) deposit of
Bahia, Brazil, as occurring in the form of a sheet or bed of from a
few decimeters to ten meters thickness, standing at an angle of 60^
in decomposed mica schist (Fig. 26.)
'Qog manganese is described as occurring in an extensive deposit
near Dawson settlement, Albert County, New Brunswick, on a
branch of Weldon Creek, covering an area of about 25 acres. In
the center it was found to be 26 feet deep, thinning out toward
the maigin of the bed. The ore is a loose, amorphous mass, which
could be readily shoveled without the aid of a pick, and contained
more or less iron pyrites disseminated in streaks and layers, though
large portions of the deposit have merely a trace. The bed lies In a
valley at the northern base of a hill, and its accumulation at this
particular locality appears to be due to springs. These springs are
rtill trickling down the hillside, and doubtless the process of pro-
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laS THE NON-METALLIC MINERALS.
ducing bog manganese is still going on.' A bed of manganese ore
in the government of Kutais, in the Caucasus, is described as occur-
FiG. a6. — Sections of manganese deposit near Bahia, Brazil.
[After Braoner, Transactions of the American Institute of Mining Engineere.]
ring in nearly horizontally lying Miocene sandstones. The ore is
pyrolusite and the bed stated as beii^ 6 to 7 feet in thickness.^
Mining and preparation. — The mining and preparation of man-
ganese ores is, as a rule, a comparatively simple process. At the
Crimora (Virginia) mines the material is excavated by means of
shafts and tunnels, and taken to the surface, where it is crushed,
washed, screened, and dried for shipment. The machinery all
works automatically, and the ore is not handled after having once
passed into the crusher.'
' Annual Report of ttie Geological Survey of Canada, VII, 1S94, p. 146 M.
' F. Drake, Transactions of the American loaiiiute o( Mining Engineers, XXV,
1898, p, 131-
* The washing plant and a vertical section of the works of the Crimora Mines are
given in the Engineering and Mining Journal for March 32, iSgo, the same having
drawn for its information on the American Manufacturer of Pittsburg. (Date not
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OXIDES.
1^9
Uses. — The various uses to which manganese and its compounds
are put may be divided into three classes: AHoys, oxidizers, and
coloring materials. Each of these classes includes the application
of manganese in sundry manufactured products, or as a reagent
in carrying on difTerent metallurgical and chemical processes. The
most important of these sources of consumption may be summarized
as follows:
° I Without iron,
\ An alloy of maDgancse, Bluminum, zinc.
Silver bronze i and copper, wiui a ccTtain quantity of
( silicon.
Alloys of mangaaesc with aluminum, nnci tini lead, mag-
Coloring materials..
Manufacture of chlorine.
Manufacture of bromine.
As a decolorizer of gloss (also for coloring glass, see coloring
materials).
As a diyer in varnishes and paints.
LcClajich('s battery.
Preparation of oxygen on a small scale.
Manufacture of disinfectants (manganates and permanganates).
Calico printing and dyeing.
Coloring glass, pottery, and brick-
Paints
1 Violet.
Besides these main uses a certain amount is utilized as a flux in
smelting silver ores, and, in the form of its various salts, is employed
in chemical manufacture and for medicinal purposes. Pyrolusite
and some forms of psilomelane are utilized in the manufacture of
chlorine, and for bleaching, deodorizing, and disinfecting purposes,
also in the manufacture of bromine.
In glass manufacture the manganese is used to remove the green
color caused by the presence of iron, and to impart violet, amber,
and black colors.
The amoimt of manganese actually used for other than stricdy
. metallurgical purposes in the United States is, however, small,' The
value depends somewhat upon the uses to which it is to be applied.
■ Miaetal Resources of the United States, i
)». P- 178-
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13°
THE NON-METALLIC MINERALS.
Pyrolusite and psilomelane only are of value in the production
of chlorine as above noted. These are rated according to their
percentages of peroxide of manganese (Mn02). The standard for
the German ores is given at 57 per cent Mn02, and 70 per cent
for Spanish. For the manufacture of spiegeleisen the prices are.
based on ores containing not more than 8 per cent silica and 0.10
per cent phosphorus, and are subject to deductions as follows:
For each i per cent silica in excess of 8 per cent, 15 cents a ton;
for each 0.02 per cent phosphorus in excess of o.io per cent, i cent
per unit of manganese. Setdements are based on analysis made
on samples dried at 212°, the percentage of moisture in samples
as taken being deducted from the weight. The prices paid at
Bessemer, Pennsylvania, in 1894, based on these percentages, were
as below:
Prica per Unit.
Iron,
6
6
6
6
CenU
2S
16
Otherwise expressed, the value ranges from $5 to $12 a ton,
according to quality and condition of the market.
The total aimual output of mines in the United States is but
some 5,000 to 6,000 tons. This because with the exception of those
at Crimora, Virginia, the deposits are of low grade or small in size.
It is probable that the total consumption in pottery and glass
manufacture does not exceed 500 tons a year, of which about two
thirds are used in glass making. The amount ti&ed in bromine manu-
facture and the other purposes enumerated probably amounts to
another 500 tons. The remainder is used in connection with iron and
steel manufacture, chiefly in the production of steel and a pig iron
containing considerable manganese for use in cast-iron car wheels.
In the crucible process of steel manufacture mai^anesc is charged
into the pots, either as an ore at the time of charging the pots, or it
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is added as spiegeleisen or ferromanganese at the time of charging
or during the melting, usually toward the dose of the melting, so
as to prevent too great a loss of manganese by oxidation. In the
Bessemer and open-hearth process the manganese is added as spiegd-
eisen or ferromanganese at or near the close of the process, just
before the casting of the metal into ingots.
It has been found in recent years that a chilled casi-iron car
wheel containii^ a percentage of manganese is much tougher.
Btronger, and wears better than when manganese is absent. For
this reason large amounts of manganiferous iron ores are used in
the manufacture of Lake Superior pig iron intended for casting
into chilled cast-iron car wheels. (See also The Mineral Industry,
Vni, 1899.)
II MINERAL WATESS.
From a strictly scientific standpoint any water is a mineral water,
since water is itself a mineral — an oxide of hydrogen. Common
usage has, however, tended toward the restriction of the name to
such waters as carry in solution an appredable quantity of other
mineral matter although the actual amounts may be extremely
variable.
Of the various salts held in solution, those of sodium, calcium,
and iron are the more common, and more rarely, or at least in
smaller amounts, occur those of potassium, lithium, magnesium,
strontium, silicon, etc. The most common of the acids is carbonic,
and the next probably sulphuric.
Classification. — ^The classification of mineral water is a matter
attended with great difficulty from whatever standpoint it is ap-
proached. Such dassification may be either geographic, geologic,
therapeutic, or chemical, though the first two are naturally of little
value, and the therapeutic, with our present knowledge, is a prac-
tical impossibility. The chemical classification is, on the whole,
preferable, although even this, owing to the great variation of methods
of stating results used by analytical chemists, is at present attended
with some difficulty. Dr. A. C. Peale, the well-known authority
on American mineral waters, has su^ested the scheme given below,'
' Annual Report of the United States Geologicfti Survey, 1891-93, p. 64.
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ija THE NON-METALLIC MINERALS.
and from his writings has been gleaned a majority of the facts here
given.
According to their temperatures as they flow from the springs
the waters are divided primarily into (A) thermal and (B) non-thermal,
a thermal water being one the mean annual temperature of which is
70° F. or above. Each of these groups is again subdivided according
to the character of the acids and their salts held in solution as below:
Clan I. Alkaline.
°" "•=■*» jsats-
ISuIpbated.
Any spring of water may be characterized by the presence or
absence of gas when it is designated by one of the following terms:
(i) Non-gaseous {free from gas). (3) Carbonated (containing car-
bonic-acid gas). (3) Sulphureted (containing hydrc^en sulphide).
(4) Azotizcd (containing nitrogen gas). (5) Carbureted (having
carbureted hydrogen).
In cases where there is a combination of gases such is indicated
by a combination of terms, as sulphocarbonated, etc. The classes
may be further subdivided according to the predominating salt in
solution, as (i) sodic, (2) lithic, (3) potassic, (4) calcic, (5) magneac^
(6) chalybeate, (7) aluminous.
The alkaline waters, Class I above, include those which are
characterized by the presence of alkaline carbonates. Generally such
are characterized also by the presence of free carbonic add. Neariy
one-half the alkaline springs of the United States are caldc-alkaline,
that is, carry calcium carbonate as the principal constituent. The
saline waters indude those in which sulphates or chlorides predomi-
nate. They are more numerous than are the alkaline waters. The
alkali-saline class indudes all waters in which there is a combination
of alkaline carbonates with sulphates and chlorides; the add class
includes all those containing free add, which is mainly carbonic,
though it may be silicic, muriatic, or sulphuric.
The character of the salts held in solution is the same for both
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thermal and non-thermal springs, thoug'i as a general rule the amount
of salt is greatest in those which are classed as thermal. Thus at
the Hot Sprii^ of \'irgiiiia one of the springs, with a temperature of
78° F., has 18.09 grains to the gallon of solid contents, while another,
with a temperature of no'* F., has 33.36 grains to the gallon.
Source 0/ mineral w<Uers. — Pure water is an universal solvent and
its natural solvent power is increased through the carbonic acid
which it takes up in its passage through the atmosphere, and by this
same acid and other organic and inorganic acids or alkalies which
it acquires in passing through the soil and rocks. The water
of all springs is meteoric, that is, it is water which has fallen upon
the earth from clouds, and gradually percolatii^ downward issues
again in the form of springs at lower levels. In this passage through
the superficial portion of the earth's crust it dissolves the various
salts, the kind and quantity being dependent upon the kind of
rocks, the temperatures and pressure of the water, as well as the
amount of absorbed gases it contains.
Both the mineral contents and the temperature of spring waters
are dependent upon the geological features of the countiy they
occupy. As a rule springs in regions of sedimentary rocks carry a
larger proportion of salts than those in regions of eruptive and meta-
morphic rocks. Thermal springs are limited to regions of com-
parative recent volcanic activity, or where the rocks have been
disturbed, crushed, folded, and faulted, as in mountainous regions.
Occasional thermal springs are met with in undisturbed areas, but
such are regarded as of deep-seated origin, and to owe their tempera-
tures to the great depths from which they are derived.
Distribution, — Mineral springs of some sort are to be found in
each and all of the States of the American Union, though naturally
the resources of the more sparsely settled States have not as yet been
fully developed. For this reason the table given on page 134 is to
a certain extent misleading.
Uses. — The mineral waters are utilized mainly for drinking and
bathing purposes, the thermal springs being naturally best suited for
bathing, and the non-thermal for drinking purposes.
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THE NON-MBTALUC MINERALS.
PKODDCTION or lOHEEAL WATERS IN 1899 BY STATES AND TEKRnOKIES.
State or Territory.
Alabama
Arkansas
California
Colorado
Connecticui
Florida
Indiana
Kentucky
Louisiana
Maryland
Massachusetts . .
Michigan
Minnesota
Missouri . .
Nebraska
New Hampshire
New Jersey
NewMenco
New York
North Carolina
Ohio
Oklahoma
Pennsylvania
Rhode Island
South Carolina
Tennessee
Teias
Vermont
Virginia
Washington
West Vi^nia
Wisconsin
Stales or Territories of 01
Toul
(gilloiis).
99,193
1.175.053
1,960,770
761,150
"3.S53
346,198
685,763
615,419
493.500
370,943
7<)7,'r
681,811
48.498
835.349
'.199.013
8,007,093
1,409,598
534.ti4
35.350
1.430.489
594.208
171,571
56,108,810 (7,387,269
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CARBONATES.
V. CARBONATES.
CALCIUM CARBONATE.
Caldte, Calc Spa;, Iceland Spar. — These are the names given
to the variety of calcium carbonate crystallizing in the rhombohedral
division of the hexagonal system. The mineral occurs under a great
variety of crystalline forms, which are often extremely perplexing
to any but an expert mineralogist. The chief distinguishing charac-
teristics of the mineral are (i) its pronounced cleav^e, whereby it
splits up into rhombohedral forms, with smooth, lustrous faces,
and (2) its doubly refracting property, which is such that when
looked through in the direction of either cleavage surfaces it gives a
double image. It is to this property, accompanied with its trans-
parency, that the mineral, as a crystallized compound, owes its
chief value, though as a constituent of the rock limestone it is applied
to a great variety of industrial purposes. When not sufficiently
transparent for observing its doubly refracting properties the mineral
is readOy distinguished by its hardness (3 of Dana's scale) and its
easy solubility, with brisk effervescence, in cold dilute acid. This
last is likewise a characteristic of aragonite, from which it can be
distinguished by its lower specific gravity (2.65 to 3.75) and its
cleavage. Calcium carbonate, owing to its ready solubility in
terrestrial waters, is one of the most common and widely disseminated
of compounds. Only the form known as double spar, or Iceland
spar, will here be considered.
Origin and mode of occurrence. — Calc spar is invariably a second-
ary mineral occurring as a deposit from solution in cracks, pockets,
and crevices in rocks of all kinds and all ages. The variety used
for optical purposes differs from the rhombohedral cleavage masses
found in innumerable localities only in its transparency and freedom
from fiaws and impurities. The chief commercial source of the
mineral has for many years been Iceland, whence has arisen the
term Iceland spar, so often applied. For the account of the occur-
rences of the mineral at this locality, as given below, we are indebted
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136 THE NON-METALUC MINERALS.
mainly to Th. Thoroddsen.' The quarry is described as atuated
on an evenly sloping mountainside at Reydarfjord, about 100 meters
above the level of the ocean and a little east of the Helgustadir farm.
(See Plate XII.)
The veins of spar are in basalt, and at this spot have been laid
bare through the erosive action of a small stream called the " Silfur-
lakur," the Icelandic name of the spar being " Silfurberg " The
quarry opening is on the western side of this brook, and at date
of writing was some 72 feet long by 36 feet wide (see Fig. 1 of plate).
In the bottom and sides of this opening the calc spar is to be seen in
the form of numerous interlocking veins, ramifying through the basalt
in every direction and of very irregular length and width, the veins
pinching out or opening up very abruptly. In Fig. 2 of plate is
shown an area of some 40 square feet of the basaltic wall rock, illus-
trating this feature of the occurrence. Fig, 3 of the same plate
shows the largest and most conspicuous vein, the smaller having been
omitted in the sketch. The high cliffs on the north side of the
quarry are poorer in calc-spar veins, the largest dipping underneath
at an angle of about 40°.
A comparatively small proportion of the calc spar as found is
fit for optical purposes. That on the immediate surface b, as a rule,
lacking in transparency. Many of the masses, owing presumably
to the development of incipient fractures along cleav^e lines,
show internal, iridescent, rainbow hues; such are known locally as
" litsteinar" (lightstones). Others are penetrated by fine, tube-like
cavities, either empty or filled with clay, and still others contain
cavities, sometimes sufi&ciently large to be visible to the unaided eye,
filled with water and a moving bubble. The most desirable material
occurs in comparatively small masses embedded in a red-gray clay,
filling the vein-like interspaces in the bottom of the pit. The non-
t.ansparcnt variety, always greatly in excess, occurs in cleavable
masses and imperfectly developed rhombohedral, sometimes i to 2
feet in diameter, associated with stilbite.
Calc spar has been exported in small quantities from Iceland
since the middle of the seventeenth century, though the business
■Geok^ka Forcningens I, Stockholm Forhandlingar, XII, 189a, pp. 347-154.
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I' late: xri.
s Showing Otrurrcnte of Cakf;e in Ictlanil.
[AflcrThorrwlilseii,]
[Foci'ig piigf i3f>L^
b,L.ooglc
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CARBONATES. 137
was not conducted with any degree of regularity before the middle
of the nineteenth century, prior to that time every one taking what he
-liked or could obtain, askii^ no one's permission. About the time
Bartholin discovered the valuable optical properties of the mineral
(in 1669), the royal parliament under Frederick III granted the
necessary permission for its extraction,' It was not, however, until
1850 that systematic work was begun, when a merchant by the
name of T. F, Thomsen, at Seydisfjord, obtained permission of the
owner of some three-fourths of the property (the pastor Th. Erlends-
son) to work the same. The quarried material was then transported
on horseback to the Northfjord, and thence to Seydisfjord by water.
In 1854 the factor H. H. Svendsen, from Eskifjord, leased the pastor's
three-fourths' right for 10 rigsdalers a year, and the remaining fourth,
belonging to the Government, for 5 rigsdalers. Svendsen worked the
mine successfully up to 1862, when one Tullinius, at Eskifjord, pur-
chased the pastor's three-fourths and leased the Government's share
for five years, paying therefor the sum of 100 rigsdalers (about $14
or $15). This lease was renewed for four years longer at the rate
of 5 rigsdalers per year, and for the year 187a at the rate of 100
rigsdalers, when the entire property passed into the hands of the
Government in consideration of the payment of 16,090 kroner (about
$3,800). From that time until 1882 the mine remained idle, when
operations were once more renewed, though not on an extensive
scale, owing, presumably in part, to the fact that Tullinius, the
last year he rented the mine, had taken out a sufficient quantity to
meet all the needs of the market. Over 300 tons of the ordinary
type of the spar is stated to have been sent to England and sold to
manufacturers at about 30 kroner a ton, though to what use it was
put is not stated.
M. Lebonne describes ' ramifications of the calcite veins into the
neighboring rock, which have never been worked, and it is suggested
that their exploitation might result in an increased output.
' Laws of Iceland, I, 1668, pp. 331, jaa.
'ComptM Rendus, Vol. V, 1887, p. 1144.
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138 THE NON-MET/ILLtC MINERALS.
The workings have not been carried to a sufficient depth to fully
indicate the extent of the deposit. For the most part the calcite is
rendered semiopaque by minute cracks following the gliding and
cleavage planes, and apparendy produced by pressure.
Aside from the locality at Helgustadir, calc spar in quantity
and quality for optical purposes is known to occur only at DJupi-
fjerd, in West Iceland.
Limestones. — Any rock composed essentially of carbonate of
lime is commonly designated a limestone. Pure limestone is a
compound of calcium oxide and carbonic acid in the proportion
of 56 parts of lime (CaO) to 44 parts of the acid (C02). In its
crystalline form, as exemplified in some of our white marbles, the
rock is therefore but an aggregate of imperfectly developed calcite
crystals, or, otherwbe expressed, is a crystalline granular aggr^ate
of calcite. In this form the rock is white or colorless, sufficiently
soft to be cut with a knife, and dissolves with brisk effervescence
when treated with dilute hydrochloric or nitric acid.
As a constituent of the earth's crust, however, absolutely pure
limestone is practically unknown, all being contaminated with more
or less foreign material, either in the form of chemically combined
or mechanically admixed impurities. Of the chemically combined
impprities the most common is m^nesia (MgO), which replaces
the lime (CaO) in all proportions up to 21.7 per cent, when the rock
becomes a dolomite. This in its pure state can readily be distin-
guished from limestone by its greater hardness and in its not effer-
vescing when treated with cold dilute acid. It dissolves with effer-
vescence in hot acids, as does limestone. As above noted, all stages
of replacement exbt, the name magnesian or dolomitic limestone
being applied to those in which the magnesia exists in smaller pro-
portions than that above given (21,7 per cent). Iron in the form
of protoxide (FeO) may also replace a part of the lime. Of the
mechanically admixed impurities silica in the form of quartz sand
or various more or less decomposed silicate minerals, clayey and
carbonaceous matter, together with iron oxides, are the more abun-
dant. These exist in all proportions, giving rise to what are known
as siliceous, aluminous, or clayey, carbonaceous, and ferruginous
limestones. Phosphatic material may exist in varying proportions,
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Fig. 1. — Limestone Qiiarry, Rockland, Maine,
n photograph by E. S. Bastin, U. S. Geological Survey'.]
Fic. 2. — Limestone Quarry, Oglesby, Illinois.
a photograph by E. C. Eckel, I!. S. Geok^ical Surv.
PLATF. XIII. I
[Facing page
jOOQ Ic
■e 1.8.1 •^'
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CARBONATES. 139
forming gradatioDS from phosphatic limestones to true phos-
phates.
Limestones are sedimentary rocks formed mainly through the
deposition of calcareous sediments on sea bottoms; many beds,
however, as the oolitic limestones, show unmistakable evidences of
true chemical precipitation. They are in all cases eminently strati-
fied rocks, though the evidences of stratification may not be evident
in the small specimen exhibited in museum collections. Varietal
names other than those mentioned above are given, and which are
dependent upon structural features, adaptability to certain uses, or
other peculiarities. A shaly limestone is one partaking of the nature
of shale. Chalk is a fine pulverulent limestone composed of shells
in a finely comminuted condition and very many minute foramin-
ifera, as ebewhere noted. The name chalky limestone is frequently
given to an earthy limestone resembling chalk. Marl is an impure
earthy form, often containing many shells, hence called shell marl.
An oolitic limestone is one made up of small rounded pellets like
the roe of a fish; a hydraulic limestone one suited to the manufac-
ture of hydraulic cement, and so on. The name marble is given
to any calcareous or even serpentinous rock possessing sufi&cient
beauty to be utUized for omament;il purposes.
Uses. — Aside from their uses as building materials as described
elsewhere,! limestones are utQized for a considerable variety of
purposes, the most important being that of fluxes and the manu-
facture of mortars and cements. Their adapatility to the last men-
tbned purposes is due to the fact that when heated to a temperature
of 1,000" F. they lose their carbonic acid, becoming converted into
anhydrous calcium oxide (CaO), or quicklime, as it is popularly
called; and further, that this quicklime when brought in contact
with water and atmospheric air greedily combines with, first, the
water, forming hydrous calcium oxide (CaOH20), and on drying
once more, with the carbonic acid of the air, forming a more or le s
hydrated calcium carbonate. In the process of combining with
water the burnt lime (CaO) gives off a large amount of heat, swells
to nearly twice its former bulk, and falls away to a loose, white
' See Slones for Building and Decoration. Wiley & Sons, New Yorlc
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I40 THE NON-METALUC MINERALS.
powder. This when mixed with siliceous sand forms flie commoa
mortar of the bricklayers, or, if with sand and hair, the plaster for
the interior walls of houses. Quicklime formed from fairly pure
calcium carbonate sets or hard,ens after but a few days' exposure,
the induration, it is stated, being due in part to crystallization. The
less pure forms of limestone, notably those which contain upwards
of lo per cent of aluminous silicates (clayey matter), furnish, when
burned, a lime which slakes much more slowly — so slowly, in fact,
that it is not infrequently necessary to crush it to powder after burn-
ing. The same limes when slaked are further differentiated from
those already described by their property of setting (as the process
of induration is called) under water. Hence they are known as
hydraulic limes or cements, and the rocks from which they are made
as hydraialic limestones. Their property of induration out of con-
tact with the air is assumed to be due to the formation of calcium
and aluminum silicates.* Inasmuch as these silicates are practically
insoluble in water, it follows that quite aside from their greater
strength and tenacity they are also more durable; indeed there seems
no practical limit to the endurance of a good hydraulic cement, its
hardness increasing almost constandy with its antiquity. Certain
stones contain the desired admixtures of lime and clayey matter in
just the right proportion for making hydraulic cement, and are '
known as natural cement rock. In the majority of cases, however,
it has been found that a higher grade, stronger and more enduring
material, can be made by mixing in definite proportions, determined
by experiment, the necessary constituents obtained, it may be, from
widely separated localities. As noted above m^nesia is a common
constituent of limestone and from the present standpoint it may be
considered as an impurity. In the natural cements, however, the
presence of an amount under 20 per cent is not considered as detri-
mental, provided the alumina and silica are present in sufficient
' As assumptbn 3ret awaiting proof. Eckel, however, gives this assumed silicate
in Portland cemeni, as having the approiimaie formula jCaCSiO,, (vhich corre-
sponds to the proportion of 73.6 per cent CaO and 16.4 per cent SiO,. As a matter
of fact, however, analyses of cements show invariably the presence of more oc less
alumina, and if such silicates are actually formed they must be of a more complex
nature, and it is possible the mixture would be best represented by the formula
3(3CaOSiO,).y (aCaOAIjOO-
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CARBON>4TES. 141
propordoDS. A higher temperature is, however, necessat7 for burn-
ing than with the pure lime carbonate. In the making of the artifi-
cial admixture the presence of magnesia in amounts exceeding 5
per cent is considered undesirable.
The exact relationship existing between composition and adaptabil-
ity to lime-making does not seem as yet to be fully worked out As
is well known, the pure while crystalline varieties yield a quicklime
inferior to the softer blue-gray, less metamorphosed varieties. Never-
theless, there are certain distinctive qualities, due to the presence and
character of impurities, which led Gen. Q. A. Gillmore to adopt the
following classification:
(i) The common or fat Ernes, containing, as a rule, less than 10 per
cent of impurities.
(3) The poor or meagre limes, containing free silica (sand) and other
impurities in amounts varying between 10 per cent and 25
per cent.
(3) The hydraulic times, which contain from 30 to 35 per cent of
various impurities.
(4) The hydrauUc cements, which may contain as much as 60
per cent of impurities of various kinds.
Most cemmts are manufactured from artificial admixtures of
materials, and their considerations bdong, therefore, more properly
to technology. Nevertheless it has been thought worth the while
here to give in brief the matter below relative to a few of the more
important and well-known varieties now manufactured.
Portland Cement. — This takes its name from a resemblance
of the hardened material to the well-known limestone of the
island of Portland in the English Channel. As originally made on the
banks of the Thames and Medway, it consists of admixtures of chalk
and clay dredged from the river bottoms, in the proportions of three
volumes of the former to one of the latter, though tljiese proportions
may vary according to the purity of the chalk. These materiab are
mixed with water, compressed into cakes, dried and calcined, after
which it is ground to a fine powder and is ready for use. The
following analyses from Heath's Manual of Lime and Cement will
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143 , THE NOS-METALUC MINERALS.
serve to show the varying composition of the chalk and clay from the
English deposits:
UppCT chBlk.
G™y chalk.
Clay.
97.90 to 98.60
.66 1.59
■35 -74
87-35 to 96..'ii
..67 6.84
.10 .50
.38 .46
•14 -93
-41 4.39
.
1 55 to 70
3 '5
3 4
4 8
4 5
It is stated that the presence of more than very small quantities
of sand, iron oxides, or vegetable matter in the clay is detrimental.
A good cement mud before burning may contain from 68 to 78
per cent of calaum carbonate, 21 to 15 pei cent of silica, and from
10 to 7 per cent of alumina.
The following analyses from the same source as the above serve
to show (I) the composition of the clay; (II) the mixed day and
chalk or " slurry," as it is called, and (III) the cement powder pre-
pared from the same:
civ.
A.
Csnoit.
62.13
a.13
4.48
69.97
11.77
30.4S
8.0s
1.48
15-03
»13
i.a4
7-59
Eckel defines ' a Portland cement, as the term is now commercially
used, as the product obtained by finely pulverizing a clinker formed
by burning to semifusion an intimate artificial mixture of finely
ground calcareous and argillaceous material, consisting approx-
' Cements, Limes and Plasters. Wiley & Sons, New York.
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CARBONATES.
H3
imately of three parts of lime carbonate to one part of sQica, alumina
and iron oxide. The ratio of lime (CaO) in the finished product,
to all other constituents named, should not be less than 1.6 to i, or
more than 3.3 to i.
Several brands of Portland cement are now manufactured in
America on the above basis, the proportions having been worked
out by experiment. At the Coplay Cement Works, in Lehigh County,
Pennsylvania, a blue-gray crystalline limestone and dark-gray more
siliceous variety are ground and mixed into the desired proportions,
molded into a brick, and burnt to the condition of a slag. The
material is then ground to a powder and forms the cement.
The chemical composition of the samples as given are as follows:
Constitoentfl.
Cement Comijpund
SiUca (SiO.)
Alumina (ALO,)
Iron Oxide (Fe,0,)
Calcium carbonate (CaCO^
MognesiaD Caibonste (MgCO,) .
An impure limestone, forming a portion of the water-lime group
of the Upper Silurian formations at Buffalo, New York, forms a
"natural cement" rock which is utilized in the manufacture of the
so-called Buffalo Portland Cemait'
The so-called Rosendale cement is made from the Tentaculite or
Water Limestone of the lower Helderberg group as developed in
the township of Rosendale, Ulster County, New York. According
to Darton' there are two cement beds in the Rosendale-Whiteport
region, at Rosendale the lower bed or dark cement averaging some
21 feet in thickness and the upper or light cement 11 feet, with 14
to 15 feet of water-lime intervening. In the regjon just south of
Whiteport the upper white cement beds have a thickness of 12 feet
and the lower or gray cement of 18 feet, with 19 to 20 feet of water-
lime beds between them. The underlying formation is quartzite.
'Cement Rock and Gypsum Depoails in Buffalo, J. Pohlman,
the American Institute of Mining Engineers, XVII, 1SS9, p. 350.
■ Report of the Stale Geologist of New York, I, 1893.
Tiatuacttons of
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144 THE NQN-METALLIC MINERALS.
The method of mining the material from the two beds, as well as
their inclination to the horizon, is shown in Plate XlV.
Rotnan Cement. — The original Roman cement appears to have
been made from an admixture of volcanic ash or sand (pozzuolana,
peperino, trass, etc.) and lime, the proportions varying almost
indefinitely according to the character of the ash. The English
Roman cement is made by calcining septarian nodules dredged up
from the bottoms of Chichester Harbor and off the coast of Hamp-
shire, and from similar nodules obtained fn»n the Whitby shale
beds of the Lias formations in Yorkshire and elsewhere. The
following analysis of the cement stone from Sheppey, near South
End, will serve to show the character of the material:
'I
6
3
75
IS
SO
oo
lOO.OO
The names concrete and beton are applied to admixtures of mor-
tar, hydraulic or otherwise, and such coarse materials as sand,
gravel, fragments of shells, tiles, bricks, or stone. According to
Gillmore the matrix of the beton propor is a hydraulic cement,
while that of the concrete is non- hydraulic. The terms are, however,
now used almost synonymously.
Aside from their uses as above indicated limestones are used in
the preparation of lime for fertilizing purposes. For this purpose,
as before, the lime carbonate is reduced to the condition of oxide
by burning and then allowed to become air-slaked, when it remains
in the condition of a fine powder suitable for direct application to
the land as is the plaster made from gypsum. A lime prepared by
burning oyster shells is utilized in a similar manner.
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If
sis
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jvGooi^lc
CytRBONATES. 145
Finely ground raw limestone is sometimes used with good effect.
In regions favorably situated, as the salt regions of Mkhigan, large
quantities of limestone are used in the manufacture of soda ash, or
carbonate of soda, which in its turn is used in the manufacture of
glass. Limestone of a high degree of purity is required for this
purpose.
The name chalk is givoi to a white, somewhat loosely coherent
variety of limestone composed of the finely comminuted shells of
marine mollusks, among which microscopic forms known as
foraminifera are abundant The older text-books gave one to
tmderstand . that foraminiferal remains constituted the main
mass of the rock, but the researches of Sorby * showed that
fully one-half the material was finely comminuted shallow-water
forms, such as inoceramus, pecten, ostrea, s[>onge spicules, and
echinoderms.
Chalk belongs to the Cretaceous era, occurring in beds of varying
thickness, alternating with shales, sands, and clays, and often in-
cluding numerous nodules of a dark chalcedonic silica to which the
name flint is given. Though a common rock in many parts of Europe,
it is known to American readers mainly by its occurrence in the
form of high cliffs along the English coast, as near Dover. Until
within a few years little true chalk was known to exist within the
limits of the United States. According to Mr. R. T. Hill' there are,
however, extensive beds, sometimes 500 feet in thickness, extending
throughout the entire length of Texas, from the Red River to the
Rio Grande, and northward into New Mexico, Kansas, and Arkansas.
These chalks in many instances so closely simulate the English
product, both in physical properties and chemical composition, as
to be adaptable to the same economic purposes. The following
analyses from the report above alluded to serve to show the com-
parative compoation:
' Address lo Geological Socitiy of London, February, 1879.
' Annual Report of the Arkansas Geologiotl Survey, II, 188S.
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THE NON-METALUC MINERALS.
ConatLtumts.
Lower
Count/.
Comfon.
Arkanus.
White
aiff
Chaik,
93.41
1.38
"■59
■41
88.48
Trace.
9-77
94-18
'■37
3-49
1.41
98.40
.08
94-09
■31
3^6.
Carbonate of maEnesia .
Silica and insoluble silicates....
Fhosplloric acid, alumina, and loss
.41
Trace.
J.V)
-70
..8
■55
99-98
99-50
,ox
TOO
.00
Chalk is used as a fertilizer, either in its crude form or burnt, in
the manufacture of whiting, in the form of hard lumps by carpenters
and other mechanics, and in the manufacture of crayons. Washed,
chalk is used to give body to wall paper; as a whitewash for ceilings;
as a thin coating on wood designed for gilding, being for this purpose
mixed with glue; to vary the shades of gray in water-color paints,
and as a poHshing powder for metals.
The marl conamonly used in cement work is described by Eckel as
a fine-grained friable limestone which has been deposited in the beds
of existing or recently extinct lakes. The deposition of the lime may
have been due simply to the escape of the excess of carbonic acid
necessary for holding it in solution, or to the abstraction of the car-
bonic acid by plants, particularly algae and mollusks, in the two
last cases the remains of the organisms constituting an appreciable
portion of the material. The beds are lenticular or basin-shaped,
and of relatively small size — a natural consequence of their mode of
origin, and limited largely to the lake countries of glaciated regions.
Playing Marbles. — At Oberstein on the Nahe, Saxony, playing
marbles are made in great quantities from limestone. The stone is
broken into square blocks, each of such size as to make a sphere
the size of the desired marble. These cubes are then thrown into
a mill consisting of a flat, horizontally revolving stone with numerous
concentric grooves or furrows on its surface. A block of oak of
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C^RBON^TES. 147
the same diameter as the stone and resting on the cubes is then
made to revolve over them in a current of water, the cubes being
thus reduced to the spherical form. The process requires but about
fifteen minutes.
Lithographic Limestone. — For the purpose of lithography
there is used a fine-grained homogeneous limestone, breaking with
an imperfect, shell-like or conchoidal fracture, and as a rule of a
gray, drab, or yellowish color. A good stone must be sufficiently
porous to absorb the greasy compound which holds the ink and
soft enough to work readily under the engraver's tool, yet not too
soft. It must be uniform in texture throughout and be free from all
veins and inequalities of any kind, in order that the various reagents
used may act upon all exposed parts alike. It is evident, therefore,
that the suitability of this stone for practical purposes depends
more upon its physical than chemical qualities. An actual test
of the material by a practical lithographer is the only test of real
value for stones of this nature. Nevertheless, the analyses given
on the next page are not without interest as showing the variation
in composition even in samples from the same locality.
Localities. — Stones possessing in a greater or less degree the
proj>er qualities for lithographic purposes have from time to tune
been reported in various parts of the United States; from near
Bath and Stony Stratford, England; Ireland; Department of Indre;
France, and also Silesia, India, and the British American possessions.
By far the best stone, and indeed the only stone which has as yet
been found to satisfactorily fill all the requirements of the hthcg-
rapher's art, and which is the one in general use to-day wherever
the art is practiced, is found at Solenhofen, and Pappenheim, on the
Danube, in Bavaria. These beds are of Upper Jurassic or Kimmer-
ic^an Age and form a mass some 80 feet in thickness, though natu-
rally not all portions are equally good or adapted for the same kind
of work. The stone varies both in texture and color in different
parts of the quarry, but the prevailing tints are yellovrish or drab.
In the United States materials partaking of the nature of lithographic
stone have been reported from Yavapai County, Arizona; Talla-
dega County, Alabama; Arkansas; Lawrence County, Indiana; near
Thebes and Anna, Illinois; James and Van Buren counties, Iowa;
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i
THE
^1
NON-METALLIC MINERALS
rrniii
a s 1 1 1 a s:
1 1 f 1 1 1 1
MMlli
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1 i ? 1 S 1 1 b 1 S S
1
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1 u .
p p
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i
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fl
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;
h
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SSI;
p p :
i 8 :
if
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1 i I
I
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p p e ;
S « S i
5 £ :
3 p :
* J
s 1 1 :
i 1 ;
1
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J, Google
CARBONATES. 149
Hardin, Estelle, Kenton, Clinton, Meade, Rowan, Wayne, and
Simpson counties, Kentucky; near Saverton, Ralls County, Missouri ;
Clay and Overton counties, Tennessee; Bumet and San Saba
counties, Texas; near Salt Lake City, Utah, and at Fincastle, Vir-
ginia. While, however, from nearly, if not quite every one of these
localities, it was possible to get small pieces which served well for
trial purposes, each and every one has failed as a constant source
of supply of the commercial article, and this for reasons mainly in-
herent in the stone itself. It is very possible that ignorance as
to proper methods of quarrying may have been a cause of failure
in some cases.
The Arizona stone according to first reports seemed very promising.
Samples submitted to the writer, as well as samples of work done upon
it, seemed all that could be desired. It is stated by Mr, W. F.
Blandy that the quarries are situated on the east slope of the Verdi
range, about 2 miles south of Squaw Peak and at an elevation of
about 1,200 feet above the Verdi Valley, 40 miles by wagon road east
of Prescott. Two quarries have thus far been opened in the same
strata, about 1,000 feet apart, the one showing two layers or beds
384 feet in thickness, and the other three beds 3,188 feet in thick-
ness. As exposed the beds, which are of Carboniferous Age, are
broken by nearly vertical Assures into blocks rarely 4 or 5 feet in
length. Owing to the massive form of the beds and the conchoidal
fracture the stone can not be split into thin slabs, but must be sawn.
No satisfactory road yet exists for its transportation in blocks of
any size, and such material as has thus far been produced is in small
slabs such as can be packed out on the backs ol animals.
The Alabama stone as examined by the writer is finely granular
and too friable for satisfactory work. Qualitative tests showed
it to be a siliceous magnesian limestone. It is, of course, possible
that the single sample shown does not fairly represent the product.
The Arkansas deposit is situated in Township 14° N., R, is" W. of
the 5th p.m., sections 14, 23, and 24, Searcy County. The color is
darker than that of the Bavarian stone- The reports of those who
have tested it are represented as being uniformly favorable.
The Illinois stone is darker, but to judge from the display made in
the IlUnois building at the World's Columbian Exposition, 1893, is
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ISO THE NON-METALLIC MINERALS.
capable of doing excellent work and can be had in slabs of good
size.
The Indiana stone is harder than the Bavarian, and samples
examined were found not infrequently traversed by fine, hard veins
of calcite.
The stone from Saverton, Missouri, is compact and fine grained,
with, however, fine streaks of calcite running through it. It leaves
only a small brownish residue when dissolved in dilute acid. This
stone has been worked quite successfully on a small scale. The
State geolo^st, in writing on the subject, says:' "Some of the
beds of the St. Louis limestone (Subcarboniferous) have been
successfully used for lithographic work. No bed is, however,
uniformly of the requisite quality, and the cost of selection of
available material would seem to preclude the development of an
industry for the production of lithographic stone."
From the deposit at Overton, Tennessee, it is stated slabs 40 by
60 inches by 3* inches thick were obtained, though little, if anything,
is now being done. An analysis of this stone is given in the table.
Other promising finds are reported from McMinn County, in the
same State. According to the State geological reports, the stone lies
between two beds of variegated marble. The stratum is thought
to run entirdy through the county, but some of the stone is too hard
for lithographic purposes. The best is found 8 miles east of Athens
on the farm of Robert Cochrane, and a quarry has been opened by
a Cincinnati company, which pays a royalty of $250 per annum.
It is sold for neariy the same price as the Bavarian stone. It is a
calcareous and argillaceous stone, formed of the finest sediment, of
uniform texture, and possesses a pearl-gray tint. The best variety
of this stone has a conchoidal fracture and is free from spots of all
kinds.
In Meade Coimty, Kentucky, the stone furnishing the best
lithographic material occurs' in a nearly horizontal layer about 3
feet in thickness. The entire output is stated to be "of good quality
for an engraving and printing base for certain classes of work." The
' Bulletin No. 3, Geological Survey of Missouri, 1890, p. 38.
'S. J. Kubel, Engineering and Minii^; Journal, November 33, 1901, p. 668.
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CARBONATES. 15^
Stone is of a blue-gray color, can be had in large sizes, and is being
quite generally used in the south and southwest, where it is stated
to compare very favorably with the imported Bavarian material. The
quarries are operated by the American Lithc^raphic Stone Company,
located at Brandenburg. In Rowan County the stone, according to
E. O. Ulrich,' occurs in nearly horizontal layers interstratified with
yellow limestone, arenaceous oolite, and shales belonging to the
St. Louis division of the Subcarboniferous formations. The quarries
now developed lie east and across the river from the town of Yale.
The bed yielding lithographic material is some 15 feet in thick-
ness, and is overlaid by an equal thickness of stripping. The
presence of flattened nodules of flint form the chief drawback as the
quarry is at present developed. The stone has been tested in the
lithographic department of the U. S. Geological Survey and found
satisfactory.
A lithographic stone is described in the State survey reports of
Texas as occurring at the base of the Carboniferous formations near
Sulphur Springs, west of Lampasas, on the Colorado River, and to
be traceable by its outcrops for a distance of several miles, the most
favorable showing ^being near San Saba. The texture of the stone
is good, but as it is filled with fine reticulating veins of calcite, and as
moreover the lithographic layer itself is only some 6 or 8 inches in
thickness, it is obvious that little can be expected from this source.
A stone claiming many points of excellence has for some years
been known to exist in the Wasatch range within a few miles of
Salt Lake City, and several companies are or have b.:en engaged in
its exploitation.
Very encouraging reports of beds examined by men whose opin-
ions should be conservative, come from Canadian sources, and it is
passible a considerable industry may yet be here developed, though
little is being done at present. The descriptions as given in the
geological reports are as follows:^
" The lithographic stones of the townships of Madoc and Mar-
mora and of the counties of Peterboro and Bruce have been examined
' Engineering and Mining Jnumal, June ag, 1901, p. S95.
'Geology of Canada, 1863.
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IS3 THE NON-METALLIC MINERALS.
and practically tested by lithographers, and in several ca?es pro-
nounced of good quality; ihey have also obtained medals at various
exhibitions. They were obtained from the surface in small quarries,
and possibly when the quarries are more developed better stones,
free from 'specks' of quartz and caldte, wilt be available in large
slabs."
It should be stated that in actual use the principal demand is
for stones some 23 or 28 by 40 inches; the largest ones practically
used are some 40 by 60 inches and 3 to 3^ inches thick. The better
grades sell as high as 22 cents a pound.
2. DOLOIUTE.
This is a carbonate of calcium and magnesium (Ca,Mg), COj,"
calcium carbonate, 54.35 per cent; magnesium carbonate 45.65 per
cent. Hardness 3.5 to 4; specific gravity 2.8 to 2 9; colors when
pure, white, but often red, green, brown, gray or black fiom impuri-
ties. Dolomite, like calcite, occurs in massive beds or strata either
compact or coarsely crystalline, and is to the eye alone often indis-
tinguishable from that mineral. Like limestone, the dolomites occur
in massive forms suitable for building purposes, or in some cases as
marble. From the limestone they may be distinguished by their
increased hardness and by being insoIub> in cold dilute hydrochloric
acids The dolomites, like the limestones, are sedimentary rocks,
though it is doubtful if the original sediments contained sufficient
magnesium carbonate to constitute a true dolomite. Th^ are
r^arded rather as having resulted from the alteration of limestone
strata by the replacement of a part of the calcium carbonate by
carbonate of magnesium.
Uses. — Aside from its use as a building material, dolomite has
of late come into use as a source of magnesia for the manufacture of
high y refractory materials for the linings of converters in the basic
processes of steel manufacture. According to a writer in the Indus-
trial World' the magnesia is obtained by mixing the calcined dolo-
mite with chloride of magnesia, whereby there is formed a soluble
"June I, i8g3.
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CARBONATES.
153
caldc chloride which ?s readily removed by solution, leaving the
insoluble magnesia behind. Accordii^ to another process the cal-
cined dolomite is treated with dissolved sugar, leading to the forma-
tion of sugar of lime and deposition of the magnesia; the solution
of sugarof lime is then exposed to carbonic acid gas, which separates
the Ume as carbonate, leaving the sugar as refuse. Recently it has
been proposed to use magnesia as a substitute for plaster of Paris
for casts, etc.
The snow-white coarsely crystalline Archean dolomite com-
mercially known as snowflake marble, and which occurs at Pleasant-
viDe, in Westchester County, New York, is finely ground and used
as a source of carbonic acid in the manufacture of the so-called
soda and other carbonated waters.
3- KAGNESITE.
This is a carbonate of magnesium, MgCO„= carbon dioxide,
53.4 per cent; magnesia, 47.6 per cent. Usual'y contaminated
with carbonates of lime, iron and free silica.
The following analysis will serve to show the average nm of
the material, both in the crude state and after calcining:
StNTi.,
Greece.
Cnide JiiagJietiU.
90.0 to 96.0
0-5
77.6
13.=
94.46
4.40
FeO 0.08
■ 0-5*
Water 0.34
81.461095,36
0.83 to io.9»
o-Sow 3-54
0.73 to 7-98
Burnt magtusile.
S""^
Alumina and ferric oxide
The mineral occurs rarely in the form of crystals, but is commonly
in a compact, finely granular condition of white or yellowish color
somewhat resembling unglazed porcelain, and more rarely crystal-
line granular, Uke limestone or dolomite.
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154 THE NON-METALUC MtUERALS.
It is hard (3.5 to 4.5) and brittle, with a vitreous luster, and is
unacted upon by cold, but dissolves with brisk effervescence in hot
hydrochloric acid.
Origin and occurrence. — The mineral is nearly, if not quh^
always secondary and, in many cases at least, a product of alter-
ation of eruptive rocks rich in olivine or other iron magnesian sili-
cates. A theoretical view of this origin, as given by various authori-
ties, is shown in the following formulas :
SMgaFeSiaOg + sCOj + 4H2O + O -
Olivine Cvbon Wmler Oxygni
dioxide
aHiMgsSijO. + FejO, + 3MgC0, + 2SiOa.
Sapentina MacnetiM Mt^ncsit* QuArts
The beds in the Swiss Tyrol are, however, regarded by M. Koch *
as due to an alteration of limestone throu^ the downward perco-
lation of magnesian solutions, a process closely akin to the now
commonly accepted idea of dolomization. The descriptions thus
far given regarding the Canadian and Styrian deposits, while not
conclusive, would seem to indicate that these m^t also result from
the alteration of beds of sedimentary origin.
It naturally follows that magnesite deposits originating through
the alteration of olivine rocks are commonly associated with ser-
pentines. Such occur, as a rule, in the form of granular aggregates
and irregular veins, some of which are apparently mere shrinkf^e
cracks, as shown in Fig. 2, Plate XV. They may vary from mere
threads to bed-like masses perhaps 20 feet in thickness. It is prob-
able, from their mode of formation, that such deposits are all
comparatively shallow, extending little, if any, below the po'manent
water level. This statement is, however, founded largely on theo-
retical considerations.
LocalUies. — Although a common mineral, magnesite in sufficient
quantities to be commercially important is comparatively rare. The
principal loccJities outside of the United States, so far as now known,
are Austria, Greece, and India, although the material is reported
' Zeil. deut. geol. Gesel. XLV, pt. a 1S93.
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— Quarry of Lilhographic Limeslone, Solenhofcn, Bavaria.
[From a photograph.]
— Slockwotk of Magnesile Veins in Serpenline, near Winthosler, Riverside
County, California.
[After F. L. Hess, Bulletin No, 355, U. S. Geological Survey.]
PLATE XV.
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CyiRBONMTES. iSS
AS occurring in Italy, Norway, Russia, South Africa, Australia, and
Mexico. In the United States the only commercially important
localities are in California, though at one time material occurring in
the form of small shrinkage cracks or gash veins in the serpcntinous
depos Is of Lancaster County, Pennsylvania, and adjacent parts of
Maryland was worked to a considerable extent, the material being
utilized in the manufacture of Epsom salts.
Attention was first directed to the California deposits by W. P.
Blake.' These were subsequently inspected by H. G. Hanks, the
State mineralogist, and have since been the subject of a special
monop'aph by Mr. Frank L. Hess ' of the United States Geological
Suivey.
According to these various authorities the Califomian deposits
are scattered along the coast range from Mendocino County as far
south as Kem and Santa Barbara counties. These are being or
have been worked in Sonoma, Santa Clara, Tulare and Napa counties.
In all cases the material occurs in connection with more or less
decomposed serpentinous rocks which are themselves a product of
decomposition of igneous rocks, of which olivine was the prevailing
constituent.
Loose boulders of a peculiar granular, almost saccharoidal form
of magnesite, looking much Ike a crystalline dolomite, have been
found for many years in the glacial drift south of Quebec, and within
a few years the material has been reported as having been found in
place in the township of Grenville. The outcrops are described as
being, in some cases, upwards of loo feet in width and to have been
traced for a distance of a quarter of a mile. The material is, how-
ever, by no means pure magnesite, but carries a varying amount,
sometimes as h^ as 40 per cent of intermixed calcite and other
impurities.
In Styria the magnesite lies- among beds of Silurian age, consisting
of argillaceous shales, quartzites, dolomites, and limestones resting
upon ^eiss. The beds in the Swiss Tyrol are said to be associated
with subcarboniferous limestone. The Grecian deposits are on the
island of Euboea on the eastern coasts. According ;o a writer in
' Pacific Railroad Reports, V, p. 308.
* Bulletin No, 355, U, S, Geological Survey, 1908.
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iS6 THE NON-METALUC MINERALS.
the Journal of the Society of Chemical Industry for May 31, 1909,
the principal deposits of Indian magnesite lie in the "Chalk Hills,"
two miles from tiie town of Salem in the Madras Presidency, where
they cover an area of some 2,000 acres, occurring in abundant
irregular veins of unknown depth, but having a total aggregate of
some 60 feet in thickness. These veins are in dunite which has
undergone alteration into serpentine with the usual secondary magne-
site, chalcedony, etc.
Uses, — In its raw state magnesite is used as a source of carbon
dioxide the gas being obtained by calcining the material in retorts.
The residue is sod to makers of efractory bricks, which are used for
basic furnaces The calcined materia! is commercially classified,
according to the temperature which has been employed, as (a) cal-
cined or caustic magnesia and (fc) dead burnt, sintered, or shrunk
magnesia. The caustic magnesia is obtained by calcining at a
temperature of 800° C. It is used for Sorel or oxychloride cements,
fireproof partitbns, plaster, artificial stone, steam packing, flooring,
grindstones, millstones, emery wheels, etc. Lai^e quantities are
used in paper manufacture. Sorel cemait is formed by mixing the
caustic magnesia with a solution of magnesian chloride. This
cement is very hard, white, and of great durability.
Th. Schlossing has proposed ' to utilize magnesian hydrate
obtained by precipitation from sea water by lime for the preparation
of fire-brick, the hydrate being first dehydrated by calcination at a
white heat, after which it is made up into brick form.
According to the Industrial World ' magnesite as a substitute
for barite in the manufacture of paint is likely to prove of impor
tance. The color, weight, and opacity of the powder add to its
value for this purpose. In Europe it is stated the material b used
as an adulterant for the cheaper grades of soap.
Prices. — During 1907 the material, 96 to 98 per cent pure, was
quoted as worth $6 to $8 a ton in New York City. Material
containing as high as 15 to 30 per cent silica and 8 to 10 per cent
of iron is said to be practically worthless. Crude magnesite is
ovGoO'^lc
1. — Magnesile Outcrop, Hixon Ranch, Mendocino County, California.
[After F. L. Hess, Bulletin No. 353, U. S. Geologica! Survey.]
Flo, I. — Sonoma Magneaile Mine, near Cazadero, California.
[After F. L. Ht»s, Bulletin No. 355, U. S. Geological Survey.]
PLATE XVI.
[Facing page 156.]
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J, Google
CARBONATES.
quoted as worth from $3 to $4 a ton at the mines in California.
The calcined material, the form in which it is sold to paper manu-
factuTO^, brings from $12 to $20 a ton. It requires about 3.4 tons
of crude to make one ton of calcined.
4. WnHESTTE.
This is a carbonate of barium of the formula BaCo^ —baryta,
77.7 per cent, carbon dioxide, 22.3 per cent. Color, white to yellow
or gray, streak white; translucent. Hardness, 3 to 3.75; specific
gravity, 4.29 to 4.35. When crystallized, usually in form of
hexagonal prisms, with faces rough and longitudinally striated.
Common in globular and botryoidal forms, amorphous, columnar,
or granular in structure. The powdered mineral dissolves readily
in hydrochloric acid, like caldte, but is easily distinguished from
this mineral by its great weight and increased hardness, as well as by
its vitreous luster and lack of rhomboidal cleavage, which is so
pronounced a feature in calcite. From barite, the sulphate of barium,
with which it might become confused on account of its high speci&c
gravity, it b readily distinguished by its solubility in acids as above
noted. From strontianite it can be distinguished by the green color
it imparts to the blow-pipe flame.
Localities and mode of occurrence. — The mineral occurs appar-
ently altogether as a secondary product filling veins and clefts in older
rocks and often forming a portion of the gangue material of metal-
liferous deposits. The principal localities as given by Dana are
Alston Moor, Cumberland, where it i; associated with galena; in
large quantities at Fallowfield, near Hexam in Northumberland; at
Anglezarke in Lancashire; at Arkendale in Yorkshire, and near
St. Asaph in Flinishire, England; Tamowitz, Silesia; Szlana,
Hungary; Leogang in Salzburg; the mine of Arqueros near Co-
quimbo, Chile; L. Etang Island; near Lexington, Kentucky, and
in a silver-bearing vein near Rabbit Mountain, Thunder Bay, Lake
Super or.
Uses. — The mineral has been used to but a shght extent in the
arts. As a substitute for lime it has met with a limhed application
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THE NON-METALLIC MINERALS.
n making plate glass, and is also said to have been used in the manu-
:'acture of beet-sugar, but is now being superseded by magnesite.
5. STRONTIANITE,
This is a carbonate of strontium, SrCOj, = carbon dioxide, 29.9
per cent; strontia, 70.1 per cent. Often impure through the presence
of carbonates and sulphates of barium and calcium. Colors, white
to gray, pale green, and yellowish. Hardness, 3.5 to 4, Specific
gravity 3.6 to 3.7. Transparent to translucent. When ciystallized
often in acute, spear-shaped forms. Also in graunlar, fibrous, and
columnar globular forms. Soluble like calcite in hydrochloric acid,
with effervescence, but readily distinguished by its cleavage and
greater density. The powdered mineral when moistened with hydro-
chloric acid and held on a platinum wire in the Same of a lamp
imparts to the flame a very characteristic red color.
Occurrence. — According to Dana the mineral occurs at Strontian
in Ai;gyllshire, in veins traversing gneiss, along with galena and
barite; in Yorkshire, England; at the Giant's Causeway, Ireland;
Clausthal in the Harz; Braunsdorf, Saxony; Leogang in Salzburg;
near Brixlegg, Tyrol; near Hamm and Miinster, Wcstphaha. In
the United States, at Schoharie, New York, in the form of granular
and columnar masses and also in crystals, forming nests and geodes
in the hydraulic limestone; at Clinton, Oneida County; Chaumont
Bay and Theresa, Jefferson County; and MifOin County, Pennsyl-
vania.
Utes. — Strontiatute, so far as the writer has information, has but
a limited application in the arts. It is stated' that "basic bricks"
are prepared from it by mixing the raw or burnt strontianite with
clay or argillaceous ironstone in such proportions that the brick
shall contain about 10 per cent of silica, and then working it into a
plastic mass with tar or some hea\'y hydrocarbon. After molding,
the bricks are dusted with fine clay or ironstone, dried, and burned.
The effect of the dusting is to form a glaze on the surface, which
protects the brick from the moisture of the air. Like celestite, it
'Journal ol the Society ot Chemical Industry, III, 1884, p. 33.
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CARBONATES. IS9
is also used in the production of the red fire of fireworks. The
demand for the material is small, and the price but from $2.50 to
$4 a ton.
6. bhodochrosite; dialogite.
This is a pure manganese carbonate of the formula MnCO„ =
carbon dioxide, 38.3 per cent; manganese protoxide, 61.7 per cent.
The color is much like that of rhodonite (see p. 204), from which,
however, it is readily distinguishable by its rhombohedral form,
inferior hardness (3,5 to 4.5), and property of dissolving with effer-
vescence in hot hydrochloric acid, while rhodonite is scarcely at
all attacked. The mineral is a common constituent of the gangue
of gold and silver ores, as at Butte, Montana; Austin, Nevada, etc.
So far as known the mineral has as yet no commercial value.
7. NATRON, THE NTTEUM OF THE ANCIENTS.
This b a hydrous sodium carbonate, Na,CO, + ioH,0, = carbon
dioxide, 15.4 per cent; soda, 21.7 per cent; water, 62.9 p>er cent.
Occurs in nature, according to Dana, only in solution, as in the
soda lakes of Egypt and elsewhere, or mixed with other sodium car-
bonates. The artificially crystallized material is of white color
when pure, soft, and brittle, and with an alkaline taste. Crystals,
thin, tabular, monoclinic. Thennonatrite, also a hydrous sodium
carbonate of the formiila Na,C0i+HjO, -carbon dioxide, 35.5
per cent; soda, 50 per cent, and water 14.5 per cent, occurs under
similar conditions, and is considered as derived from natron as a
product of efflorescence. (See 'further under Sodium sulphates,
P- 333-)
8. trona; urao.
This is a hydrous sodium carbonate, corresponding to the for-
mula Na,CO,.HNaCO, + 2H,0, = carbon dioxide, 38.9 per cent;
soda, 41.2 per cent; water, 19.9 per cent.
Found in nature as an efflorescence or incrustation from the
evaporation of lakes, particularly those of arid regions. W. P.
Blake has recently described' crude carbonate of soda (Trona)
' Engineering and Mining Journal, LXV, 1S9S, p. il
J, Google
i6o
THE NON-METALUC MINERALS.
occurring in the central portion of a basin-shaped depression or
dry lake in southern Arizona, near the head of the Gulf of California.
The deposit covers an area of some 60 acres to a depth of from i to
3 feet, the lower portion being saturated with water from a solution
so strong that when exposed to the air soda is deposited at the rate
of an inch in thickness for every ten days. In its native condition
the soda is naturally somewhat impure, from silt blown in from
the surroundii^ land. The analysis given bdow shows the general
average:
Cooitituenla.
PerCmt.
1. 14
4-7*
,5:S
Iron oiides and alumiDa
100.00
See furthw under Themardite, p. — .
BIBUOGRAPHV OF LIMES AND CEMENTS.
Out of the maaj hundieds of titles th&t might be given, a few only «ie selected.
Thooe desiring may find a veiy full bibliognLpby in a series of pa.pers on The Cliemi-
cal and Physical Examinations of P<»tlaAd Cement. Journal of the American Chemi-
cal Society, XV and XVI. ' 1893-1894.
Q. A. GiLUioitE. Practical treatiae on Limestones, Hydraulic Cements, and Mortars.
New YoA, 1863, 333 pp.
The Cement Works on the Lehigh.
Second Pennsylvania Geological Survey, Lehigh District, D. D, 1875-76, p. 59,
Hontv C. E. Reid. The Science and Art of the Manufacture of Portland Cement
with Observations on some of its Constructive Applications.
London, 1877.
JOHAHM BiELEMBEtto. Method for Utilizing Siliceous Earths and Rocks in tbt
Manufacture of Cements, tor the purpose of imparting to them Hydraulic Propers
ties. (German Patent No. 24038, November aS, 1881.)
Journal of the Society of Chemical Industry, III, 1884, p. no.
U. CtnooNcs. Hydraulic Cements, Natural and Artificial, their Compumtive Values.
Massachusetts Institute of Technology, November, 1887.
M. H. Le CHATEUea. Recherches Expirimentales sur la Constitution des Moitien.
Hydrauliques.
Chu. Dunod, Paris, 1SS7.
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SILICATES. i6i
M. A. Pkost. Note sur la Fabrication et les PropriA& dcs CiineDta de Laitier
Annales des Mines, XVI, 1889, p. 158.
H. Pearsth Bsuuell. Natural and Artificial Cements io Canada.
Science, XXI, 1893, p. 177.
M. H. Lk Cbatelies. Proc&]£s d'Essai des Matfriauz HTdrauliquM,
Annales des Mines, IV, 1893, p. 367.
A. H. Heath. A Manual of Lime and Cement
London, 1S93, 315 pp.
G. R. Redosavb. Calcareous Cements: Their Nature and Use*.
London, 1895, 232 pp.
UUAH CuMHiNCS. American Cements.
Boston, 189S, 299 pp.
Cbabi.es D. tAiiESON. Portland Cement, its Manufacture and Use.
New York, 1898, 191 pp.
Bbbnakd L. Green. The Portland Cement Industry of the Worid.
(Reprinted from Journal of the Asaodation of Engineering Societies. "XXt
June, 1898.)
E. C. Eckel. Cements, limes and Plasters. Wiley & Sons, New York, 1905.
VI. SILICATES.
L FELDSPARS.
The name feldspar is given to a group of minerab resembling
each other in being, chemically, silicates of aluminum with varying
amounts of lime and the alkalies potash and soda. All members
of the group have in common two easy cleavages whereby they
split with eveoj smooth, and shining surfaces along planes inclined
to one another at angles of nearly if not quite 90°. They vary
from transparent through translucent to opaque, the opaque form
being the more frequent. In colors they range from clear and
colorless through white and all shades of gray to yellowish, pink, and
red, more rarely greenish.
On prolonged exposures to the weather they become whitish
and opaque, gradually decomposing into soluble carbonates of
lime and the alkalies, and soluble silica, any one of which may be
wholly or in part removed by percolating waters, leaving behind a
residual product, consisting essentially of hydrous silicates of alu-
mina, to which the names kaolin and clay are given (see p. 217).
The hardness of the feldspars varies from 5 to 7 of Dana's scale;
ov Google
l6a THE NON-METALLIC MINERALS.
specific gravity 2.5 to 2.8 They are fusible only with difficulty, and
with the exception of the mineral quartz are the hardest of the
common light-colored minerals. From quartz they are readily
distinguished by their cleavage characteristics noted above. Geolog-
ically the feldspars belong to the gneisses and eruptive rocks of
all ages, certain varieties being characteristic of certain rocks and
furnishing important data for schemes of rock classification. Nine
principal varieties are recognized which on crystallographic grounds
are divided into two groups. The first, crystallizing in the mono-
clinic system, including only the varieties orthoclase and hvalophane;
the second, crystallizing in the triclinic system, including micro-
clinic, anorthoclase, and the albite-anorthite series, albite, oligo-
dase, andesine, labradorite, and anorthite. The above-mentioned
properties are set forth in the accompanying table.
Ortho-
Hy.lo-
Micro-
thoclaH
Albitg,
Olifro-
clue.
Ande-
Labra-
te
Kli<:«,aO,.. .
Aluiiuna.AM>)
6<.7
16.9
•:;•
ifi.ti
1:^
«:=
tx
6d,o
M\%
"::
11.0
8,0
4.0
16.4
'i.t^'.l
j.e-j!;
asSsrr:::
3.4-1.6
6.c>-6!<
i-xv.
>.t^S.S
6.0-1.0
..S6--.T
6.0-J.O
It;',
CryiU]i™.yt
HonocUnic.
TricKnic.
Of the above those which most concern us here are the potash
feldspars orthoclase and microcline, two varieties which for our pur-
poses are essentially identical both as regards composition and gen-
eral physical properties as well as mode of occurrence. Indeed,
although crystallizing in different systems they are as a rule indis-
tinguishable but by microscopic means or by careful crystallographic
measurements.
Occurrence. — The potash feldspars are common and abundant
constitutents of the acid rocks — such as the granites, gneisses, syen-
ites— the orthoclase and quartzose porphyries, and the Tertiary and
modem lavas — such as trachyte, phonolite, and the liparites.
Among the older rocks they frequently occur in large dikes
or vein-like masses of coarse pegmatitic crystallizatkin, the indi-
vidual crystals being in some cases a foot or more in diameter. The
ov Google
Fic. 1.— Feldspar Quarry, Topsham, Maine.
[From phoiograph by E. S. Bastin, U. S. Geological Survey.]
Fig. 1. — Feldspar Quarry, South Glastonbury, Conneclicut.
[From photograph by E. S, Baslin, U. S. Geolt^ical Survey.
PUTE xvn.
[Fating page i6».]
ov Google
J, Google
SIUCATES. 163
associated minerak are quartz and white mica, with beryl, tour-
maline, garnet, and a great variety of rarer minerals. The ordinary
white mica of commerce comes from deposits of this nature and
often the two minerals are mined contemporaneously. Such of
our feldspars as have yet been worked for ecomomic purposes occur
associated only with the older rocks — the granites and gneisses
of the Archean and Lower Paleozoic formations.
Near Topsham, Maine, is one of these pegmatitic intrusions,
rutming parallel with the strike of gneissoid schbts in which it lies, i.e.,
northeast and southwest. The quarry is in the form of an open cut
in the hillside, some 300 feet long by 100 feet wide, and of very
irregular contours. The present floor and the sides of the cut are
of feldspar, containing irregular bodies of quartz and mica, the
first named occurring in large masses entirely free from other min-
erals, though a second grade is taken out which is in reality an in-
timate mixture of quartz and feldspar.
The quartz occurs, besides as mentioned above, in the form of
irregular bodies, sometimes 6 or 8 feet across and 15 feet or more
long. It also occurs in cavities, or geodes, in the form of flattened
crystals. The mica is here of little economic importance, being
embedded in the feldspar and occurring along the seams in the form
of narrow, lanceolate masses, often arranged in small radiating con-
ical forms with their apexes outward.
It should be noted that the rock pegmatite, a coarse aggregate
of quartz and feldspar, is often mined and utilized for the same
purpose, as b the pure feldspar itself. Albite, when occurring with
the othoclase, is also mined and utilized in the same manner.
The principal feldspar quarries thus far worked are in the eastern
United States, from Maine to New Jersey. The material is mined
from open cuts, being blasted out with powder and separated from
adhering quartz, mica, and other minerals by hand, after which it
is shipped in the rough to the potteries, or in some cases ground and
bolted in the near vicinity. In times past the material has been
ground under huge granite disks mounted like the wheels of a cart
on an axle through the center of which extended a vertical shaft.
By the slow revolution of this shaft the wheels traveled around in
a limited circle over a large horizontal granite slab. The pieces of
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i64 THE NON-METALLIC MINERALS.
spar being placed upon the horizontal slab were thus slowly ground
to powder. A more modern method is by means of the so-called
Cyclone crusher. The value of the uncrushed material delivered
at the potteries is but a few dollars a ton. Hence, while there axe
unlimited quantities of the material in different parts of the Appa-
lachian region, but few are so situated as to profitably worked.
Uses. — The feldspars are used mainly for pottery, being mixed
in a finely pulverized condition with the kaolin or clay. When
subjected to a high temperature the feldspar fuses, forming a glaze
and at the same time a cementing constituent. There are other
substances more readily fusible which are utilized for this purpose
in the cheaper kinds of ware, but it is stated that in the highest
grades of porcelain, as those of Sevres, feldspar is the material used.
The proportions used vary with different manufacturers, each having
adopted a formula best adapted for his own workings.
For more than fifty years experiments have from time to time
been made with a view of extracting the potash from feldspars on
a commercial scale and also of using the ground feklspar in its crude
or raw state as a fertilizer. The cheapness of the Stassfurth potash
salts has thus far militated against the development of the first-named
industry, and while experiment has shown that plants will assimOate
a certain amount of potash from the raw, finely ground feldspar,
the effect of such appUcaUon has not proven sufficient to warrant its
general adoption.
In the same way attempts have been made to utUize &e potash
of the nepheline in phonolites, but the results have been unsuccessful,
owing to the insoluble character of the silicate.'
The labrador feldspar occurring as the chief constituent of a
gabbro near Duluth, Miimesota, is crushed and made into sandpaper
for use in woodworking.
Under thb head are comprised a number of distinct mineral
species, alike in crystallizing in the monoclinic system and having a
highly perfect basal cleavage, whereby they split readily into thin,
translucent to transparent, more or less elastic sheets. Chemically
• Deul. Landes. Prcsse, XXXVI, 1909.
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SILICATES. 165
they are in most cases orthosilicates of aluminum with potassium
and hydrogen, and in some varieties magnesium, ferrous and ferric
iron, sodium, lithium, and more rarely barium, manganese, titanium,
and chromium. Seven species of mica are commonly recognized,
of which but three have any commercial value, though a fourth
form, lepidolite, may perhaps be utilized as a source of lithia salts,
and a fifth, roscoelite,as a source of salts of vanadium. Of these three
forms the white mica, muscovite, and the pearl-gray phlogopite are
of greatest importance, the black variety, biotite, being but little
used. Muscovite, or potassium mica, is essentially a silicate of alu-
minum and potassium, with small amounts of iron, soda, magnesia,
and watCT. Its cobr is white to colorless, often tinted with brown,
green, and voUet shades. When crystallized it takes on hexagonal
or diamond-shaped forms, as do also phlogopite and biotite. Its
industrial value lies in its great power of resistance to heat and acids,
its transparency, and its wonderful fissile property, in virtue of which
it may be split into extremely thin, flexible sheets. Phlogopite,
or magnesian mica, differs from muscovite in being of a darker, deep
pearl-gray, sometimes smoky, often yellowish, brownish red, or
greenish color and lacking in transparency. Biotite, or magnesia
iron mica, differs in being often deep, almost coal black and opaque
in thick masses, though translucent and of a dark-brown, yellow,
green, or red color in thin folia. It further differs from the preceding
in that its folia are less elastic, and the sheets of smaller size. Lep-
idolite, a lithia mica, is much more rare than either of the above, is
of a pale rose or pink color, the folia usually of small size, commonly
occurring in scaly granular forms without crystal outlines. The
following table will serve to show the varying composition of the
four varieties mentioned:
Vuiety.
SiO,. 'AW)^'pey3,
FeO. ! MgO. 1 00.
Kfi-
Na^.
Hrf>.
Muicavite
4=
JI 36
66
65
IB
"oifiO
.J:w::::::
\
6.
0.49
0.80
4.83
s'46
ri
61
?6
.i:i:vi.
t-!a§
'it
-
"
■•
•■••
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i66 THE NON-METALUC MINERALS.
Although the basal cleavage which permits of the ready splitting
of the mica into thin sheets is the only one sufficiently developed
to be of economic importance, the mica as found is often traversed
by sharp lines of separation, called gliding planes, which may, by
their abundance, be disastrous to the interests of the miner. Such
partings, or glidii^ planes, supposed to be induced by pressure,
are developed at angles of about 66}" with the cleavage, and may
cut entirely through a block or extend inward from the margin only
a short distance and come to an abrupt stop. In many cases these
planes divide the mica into long narrow strips, from the breadth of a
line to several inches in thickness, with sides parallel, and as sharply
cut as though done with shears.
The imperfections in mica are due to inclosures of foreign min-
erals, as flattened garnets, to the presence of free iron oxides, often
with a most beautiful dendritic structure, to the partings or gliding
planes noted above, and to crumplings and V-like striations which
destroy its homogeneity.
Occiarence. — Mica in quantity and sizes to be of economic
importance is found only among the older rocks of the earth's crust,
particularly those of the granite and gneissoid groups. Musco-
vite and biotite are among the commonest constituents of siliceous
rocks of all kinds and ages, white phlogopite is more characteristic
of calcareous rocks. It is, however, only when developed in crystals
of considerable size in pegmatitic and coarsely feldspathic veins,
or, in the case of phlogopite, in gneissic and calcareous rocks asso-
ciated with eruptive pyroxenites, that it becomes available for eco-
nomic purposes. The associated minerals are almost too numerous
to mention. The more common for muscovite are quartz and
potash feldspar, which form the chief gangue materials in crystals
and crystalline masses, sometimes a foot or more in diameter. With
these are almost invariably associated garnets, beryls, and tour-
malines, with more rarely cassiterite, columbite, apatite, fluorite,
topaz, spodumene, uraninite, etc. Indeed, so abundant are, at times,
the accessory minerals in the granitic veins, and so perfect their
crystalline development, that they furnish by far the richest collecting
grounds for the mineralogists. Of these minerals the quartz and
ov Google
SILICATES. 167
feldspars are not infrequraitly mined contemporaneously with the
mica and utilized in the manufacture of pottery and abrasives.
Origin. — It is now commonly assumed that these pegmatitic
"veins" are undoubted intrusives, though to some authorities it
seems scarcely possible thai the extremely coarse aggregates of quartz,
feldspar, and mica, with large garnets, beryls, and tourmalines, can
be a direct result of cooling from an igneous magma. To such it
appears more probable that they are portions of an original rock
mass altered by exhalations of fluorhydric acids, like the Saxon
"greisen." Others regard them as resulting from the very slow
cooling of granitic material injected in a pasty condition, brought
about by aqueo-igneous agencies, into rifts of the pre-existing rocks.
It must be remembered that the high degree of dynamic metamorph-
ism which these older rocks have imdergone renders the problems
relating to their origin extremely difficult. As to the origin of the
Canadian phlogopite there seems no reason for not adopting the
conclusion of Cirkel, who r^ards it as a product of crystallization
from an aqueo-igneous solution, which permeated upward along
lines of fracture either in pyrosenic rocks or along the line of contact
between these rocks and the prevailing gneisses and limestones.
The common association of apatite with the phlogopite indicates
a common and practically contemporaneous origin for both.
Localilies. — From what has been said regarding occurrences, it
is evident that mica deposits are to be found mainly in regions
occupied by the older crystalline rocks. In the United States,
therefore, one need look for them only in the States bordering im-
mediately along the Appalachian range and in the granitic areas
west of the front range of the Rocky Mountains,^ In the Appa-
lachian region south of Canada mica mines, worked either for mica
alone or for quartz and felds[)ar in addition, have from time to
time been opened in various parts of Maine, New Hampshire,
Connecticut, Maryland, Virginia, North Carolina, and perhaps
other States, but in none of them, with the exception of New Hamp-
shire and North Carolina, has the business proven sufficiently
lucrative to warrant continuous and systematic working. Indeed,
''The region of the Black Hills of South Dakola is an impoitant exception.
J, Google
i68 THE NON-METMLUC MINERALS.
were it not for the increased demand lately arising for the use of
mica in electrical machines it is doubtful if any but the most favorably
situated mines would remain longer in operation in the United
States, This for the reason not so much that foreign mica is better
as that it is cheaper.
Muscovite. — In Maine muscovite has been mined in an inter-
mittent manner along with quartz and feldspar at the well-known
mineral localities at Paris Hill and Rumford, Oxford County; Au-
burn, Androscoggin County; Topsham, Sagadahoc County; Edge-
comb, Lincoln County, and other counties in the southeastern part
of the State. In New Hampshire the industry has assumed greater
importance. The mica-bearing belt is described by Professor C. H,
Hitchcock as usually about z miles in width, and extending from
Easton, in Grafton County, to Surry, in Cheshire County; being best
developed about the towns of Rumney and Hebron. The mica
occurs in immense coarse granite veins in a fibrolitic mica schist,
and is found in sheets sometimes a yard in length, but the more
common sizes are but lo or 12 inches in length. Immense beryls,
sometimes a yard in diameter, and beautiful large tourmalines occur
among the accessory minerals. Mines for mica were 0[>ened at
Grafton as early as 1840, and as many as six or eight mines have
been worked at one time, though by no means continually. Other
mines have been worked in Groton, Alexandria, Grafton, and
Alstead, in Grafton County; Acworth and Springfield, Sullivan
County; Marlboro, Cheshire County; New Hampton, Belknap
County, and Wilmot, Merrimack County.
As seen by the present writer, in 1894 the veins in Grafton County
cut sharply across the fibiolitic schist, and though the vein materials
adhere closely to the wall rock on either side, without either selvage
or slickensides, still the line of demarcation is perfectly sharp.
There seems no room for doubt but that the vein material was
derived by injection from below, though from their extremely irreg-
ular and universally coarsely crystalline condition we must infer
that the cdndition of the injected magma was more in the nature
of solution than fusion, as the word is ordinarily used, and also
that the rate of cooling and consequent crystallization was very
slow. The feldspars frequently occur in huge crystalline masses
ov Google
SIUC4TES. i69
several feet in diameter, though sometimes more finely intercrystal-
lized with quartz in the form known as pegmatite. The mica is
by no means disseminated uniformly throughout the vein, but on
the contrary is very sporadic, and the process of mining consists
merely in following up the mineral wherever indications as shown
in the face of the quarry are sufficiently promising. Most of the
mines are in the form of open cuts and trenches, though in a few
instances underground cuts have been made for a distance of a
hundred feet or more. The mica blocks as removed are of a beautiful
smoky-brown color, and often show a distinct zonal structure, in-
<]^ating several periods of growth. The associated feldspar is
not in all cases orthodase, but, as at the Alexandria mines, some-
times a faint greenish triclinic variety.
In Connecticut some mica (muscovite) has been obtained in
connection with the work of mining feldspar and quartz in and
about the towns of Haddam, Glastonbury, and Middletown, but the
business has never assumed any importance.
South of the glacial limit mica mining has proven more successful
from the reason that the gangue minerals (fddspar and quartz) are
in a state of less compact aggregation, due to weathering, the feldspar
being often reduced to the state of kaolin, and hence readily removed
by pick and shovel.
North Carolina. — It is for the above reason, in part, that the
mica industry has prospered in North Carolina more than elsewhere
in the eastern United States. The deposits here were first described
in a systematic manner by W. C. Kerr ^ in 1880, and have since been
the subject of numerous investigations on the part of the State and
United States Geological Surveys.* As in New Hampshire and else-
where the mica occurs in intrusive masses of pegmatite which have
most frequently followed the lines of least resistance in the inclosing
Archaean gneisses and schists, fonning thus what Kerr described
as bedded veins, although he recognized their mtrusive character.
The area of the mica-bearing pegmatites extends entirely across
the western part of the State in a northeasterly and southwesterly
direction, from Virginia to Georgia, but the chief centers of produc-
■ Trensaclions of Ihe American Institute of Mining Engineers, VIIT, p. 457.
' See D. B. Sterrett, Bulletin No. 315, U. S. Geological Survey, p. 400.
ovGoo'^lc
170
THE NON-METALLIC MINERALS.
tion have been in Mitchell, Yancey, Macon, Jackson, Haywood,
Ashe and Cleveland counties. (See map, Fig, 27.) Sterrett recog-
nizes three zones, or belts, (i) the Cowee-Black mountain, (2) the
Blue Ridge and (3) the Piedmont. The first runs nearly through
the State parallel with its western border; the second follows the
Blue Ridge and extends several miles to the southeast along the
foothills. It is the least important of the three. The Piedmont belt
Fig. 37. — Map showing mica -producing areas of North Carolina.
[Afler Dougbs SKrretl, Bulletin No. 315, U, S. Geological Surrcy, 1907.
lies southeast of the ridge, mainly in Cleveland, Lincoln, Burke and
Stokes counties.
The pegmatites form, for the most part, Iens-sha[>ed masses
conformable with the schistosity of the country rock in one or several
parallel planes. In cross-section some are short and bulky, with a
length but two or three times their thickness, while others are long
and tapering, often much branched, and follow the windings and con-
tortions of the inclosing rock. (See Fig, : 8.)
The size of the dikes is variable, but as a rule none are worked
of a thickness less than one ol two feet and then only when excep-
ov Google
11
p
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3-'" ^ ^ I
S-S iS- a,
* a. B
|i I
si
Is
J, Google
172 THE NON-METALUC MINERALS.
tionally rich. As elsewhere, the mica is rarely uniformly dissemi-
nated throughout the rock, nor does it keep the same relative position
in any one dike for long distances. In some of the larger dikes the.
rock is so coarsely crystalline as to yield cleavage masses of feldspar
several tons in weight, and mention is made of a feldspar crystal
weighing nearly a thousand pounds, and of sheets of mica three and
four feet in diameter.
In Alabama, along a line stretching from Chilton County, north-
east, through Coosa, Clay, and Cleburne counties, there are numer-
ous evidences of prehistoric mica mining. Many pits are met with
around which pieces of mica are still to be seen. In some places,
as in Mitchell County, North Carolina, large pine trees have grown
up on the d^ris, so that a considerable time must have elapsed
since the mines were worked.
In Colorado mica has long been known to be widely disseminated
and to occur in many places in bodies of workable size. Many
mines have been located, but the product has always proved worthless,
until in the summer of 1884 the Benver Mica Company opened a
mine near Turkey Creek, about 35 miles from Denver. This mica
is of fair quality, and quite a considerable quantity of it has been
mined. It is slightly brown, and the largest plates which have yet
been cut are not more than aj by 6 inches in size. Only an extremely
small percentage of the gross weight is available for cutting into sheets.
Mica of good quality and large plates has also been recently reported
from the neighborhood of Fort Collins.
In Wyoming mica has been found in workable quantities near
Diamond Park and in the Wind River country, as well as at many
points along the mountain ranges in Laramie County. It has recently
been mined to some extent at Whalen CaSon, 30 miles north of
Fort Laramie, and some of the product has been shipped to the
Eastern market
In New Mexico mica has been mined near Las Vegas and
Petaca. In California many deposits of mica have been noted,
especially at Gold Lake, Plumas County; in Eldorado Coimty;
Ivanpah district, San Bernardino County; near Susanville, Las-
sen County, and at Tehachapi pass, Kem County. In 1883 a
lai^e deposit was discovered in the Salmon Mountains, in
ov Google
SlUCATES. 173
the northwestern part of the State, and some prospecting was
done.^
The mica-bearing deposits of the Black Hills of South Dakota
have been variously regarded by observers as intrusive granites
or true segregation veins lying parallel to the apparent bedding.
Newton and Jenny ^ Blake,^ and Vincent regarded them as intrusive,
while Carpenter * and Crosby * held the opposite view.
According to Blake the mica occurs in granitic masses, remark-
able for the coarseness of their crystallization, the constituent min-
erals being usually large and separately segregated. " Large masses
of pure quartz are found in one place and masses of feldspar in
another, and the mica is often accumulated together instead of being
regularly disseminated through the mass. It also occurs in large
masses or crystals, affording sheets broad enough for cutting into
commercial sizes." Associated with the mica at this point are the
minerals quartz and feldspar, mainly a lamellar albite (Clevelandite),
which form the gangue, and irregularly disseminated cassiterite
(tinstone), gigantic spodumenes, black tourmalines, and, in small
quantities, black mica, beryls, garnets, columbite, and a variety of
phosphatic minerals, such as apatite, triphylite, etc.
Sterrett describes ° a mica deposit near Custer as occurring in a
pegmatite intruded into gneiss and biotite schist, dippmg with the
country rock about 50° to the southwest (See Fig. 29.) The intru-
sive is about 30 feet in thickness at the surface and 28 feet at the
300-foot level. The mica occurs in two streaks or "veins "from i to8
feet wide, along each wall, the middle portion being practically barren,
or at best too poor to work. The mica occurs mostly in flattened
or tabular blocks lying perpendicular to the walls and varying up to
5 inches in thickness and from 3 to 8 inches in diameter. Crystals
a foot in diameter are, however, not rare, while some have been found
of three times that dimension. In certain portions of the pegmatite
' Miaeial Resources of the United States, 1SSJ-S4, p. 911.
* Geology of the Block Hills of Dakota, Monograph, U. S. Geolgoical Survey, 1880.
' Engineering and Mining Journal, XXXVI, 1883, p. 145.
' Tiansaclions of the American Institute of Mining Engineers, XVII, 1SS9, p. 570 .
* Proceedings of the Boston Society of Natural History, XXIII, 1884-S8, p. 48S.
* Bulletin No. 3S0, U. S. Geological Survey, 1909.
ovGoo'^lc
174 THE NON-METALLIC MINERALS.
there occurs abundant black tourmaline in size up to lo inches in
diameter, and it is noteworthy that in these portions the mica content
is poor.
In Nevada mines have been worked in the St. Thomas mining
district, Lincohi County, the mica occurring in hard, glassy quartz
rock forming an outcrop some 200 feet wide by 600 feet long in
gneiss and schists. At the Czarina Mine, located in May, 1891,
near Rioville, the mica occurs under similar conditbns. The
. Fig. 99. — Generalized section of mica mine, near Custer, South Dakota.
[After D. Stenett, Bulletin No. 380, U. S. Geological Survey.]
mineral seems to follow the division plane of the stratification, along
the line or axis of a fold. This line runs north and south, slightly east
of north of the main trend of the range, thus running into Arizona a
few miles north of Rioville. In fact the mica belt forms the boun-
dary line between Nevada and Arizona for 50 miles. The mica,
mostly small, is abundant, but marketable sizes are rare, and not
to be had without a great deal of hard work.^
Merchantable mica has been reported on the Payette River and
Bear Creek, in the Cceur d'Alene region of Idaho, and in Oregon
and Alaska. Also in the Saguenay district of Canada; in the vicinity
of Mattawa, north of Ottawa; in Ontario and in Britbh Columbia.
' MiiKral Resources o{ the United States, 1893, p. 754.
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StUCATES. 175
The India mica mines occur in coarse intrusive p^matidc-
granite dikes, cutting what is known as the newer gneiss of
Singrauli. At Inikurti the crystals are at times as much as 10 feet
iu diameter. Sheets 4 or 5 feet across have been obtained, it is
stated, free from such adventitious inclusions as would spoil their
commercial value. ^
Phlogopite. — The occurrence of the pearl-gray mica phlogopate
in commercial quantities is much more restricted and so far as b at
present known, is limited to an area of some 520 square miles north
of Ottawa, in the province of Quebec, Canada, and in the townships
of Burgess, Lanark, and Loughborough, province of Ontario. The
deposits are closely associated with intrusive pyroxenic rocks which
penetrate the Laurentian gneisses and overlying crystalline limestone,
sometimes running parallel with the gneisses and again cutting across
Fig. 30. — Section through Lake Girard Mica Mine, Quebec, Canada.
[After Cirkct: Mica, Occuirence, Exploitation, and Uses]
tiiem. R. W, Ells has given'' thecondilionsof occurrence as follows:
' Geology of India, ad ed., 1895, p. J4.
Bulletin of the Geological Society of America, V, 1894, p. 4S4.
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176 THE NON-METALLIC MINERALS.
I. In pyroxene intrusive rocks which either cut directly
across the strike of grayish or other colored gneisses or are
intruded along the line of stratification. Some of these deposits
have been worked downward along the contact with the gneiss,
where the mica Is most generally found, for 350 feet, as at the
Lake Girard Mine (Fig. 30), and irregular masses of pink calcite
FlO. 31- — Section of vein in Baby Mint, Nortli Burgess, Ontario.
[After Cirlcel: Mica, OccurreiKe, Exptoitalion, and Uses.]
are abundant In certain places apatite crystals occur associated
with the mica, but at other times these are apparently wanting.
As in the case of apatite deposits, mica occurring in this
condition would apparendy be found at almost any workable
depth.
In pyroxene rocks near the contact of cross-dikes of diorite
or feldspar, the action of which on the pyroxene has led to the forma-
tion of both mica and apatite. Numerous instances of thb mode
of occurrence are found, both in the mines of apatite and mica,
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the deposits of the latter in certain areas being quite extensive and
the crystals of large size. (Fig. 3 1 .)
3. In pyroxene rock itself distinct from the contact with the
gneiss. In these cases the mica crystals, often of large size but
frequently crushed or broken, apparently follow certain lines of
faults or fracture. Some of these deposits can be traced for several
yards, but for the most part are pockety. Some of these pyroxene
[ Fio. 3a. — Mica-bearing pTToxene dike in gneiss. An iilustTalion of pocket deposits,
[After Cirkel: Mica, OccurrcDce, Exjdoitalion, and Uses.]
masses are very extensive, as in the case of the Cascade Mine on
the Gatineau River and elsewhere in the vicinity. In these cases
calcite is rarely seen and apatite is almost entirely absent. When
cut by cross-dikes conditions for the occurrence of mica or apatite
should be very favorable.
4. Dikes of pyroxene, often large, cutting limestone through
which subsequent dikes of dbrite or feldspar have intruded, as in
Hincks township. The crystals occurring in the pyroxene near to
the feldspar dikes are often of large size and dark color, resembling
in this respect a biotite mica, {Fig. 33.)
It is stated by Dr, Ells that when the pyroxene is of a light shade
ovGoO'^lc
178 THE NON-METALLIC MINERALS.
of greraish gray and comparatively soft, the mica is corre-
spondingly light colored and clear, and in some places ahnost
approaches the muscovite in general appearance. As the pyrox-
ene becomes darker in color and harder in texture, the mica
assumes a correspondingly darker tint and a brittle or harder
character, and in certain cases where dikes of blackish hom-
blendic diorite are present the mica also assumes a black color as
well.
The principal areas at present worked are in the belt which
extends from North Burgess, in the province of Ontario, approxi-
mately along the strikeof the gneiss into the territory adjacent to
the Gatineau and Lievre.
FlO. 33. — Mica-bearing pyroxene dike in limestone. An illustration of pocket deposits.
[After Cirkel: Mica, Occurrence, Exploitation, and Uses.]
Biotite. — Black mica (biotite, iepidomelane, etc.) is a much more
conmion and widely distributed variety than the white, but unlike
the latter is found not so much in veins as an original constituent
disseminated in small flakes throughout the mass of eruptive and
metamorphosed sedimentary rocks. The small sizes of the sheets,
their color, and lack of transparency render the material, as a rule,
of little value. In Renfrew County, Canada, the mineral occurs
in large cleavable masses, which yield beautiful smoky-black and
greenish sheets sufficiently elastic for industrial purposes.
Lepidolite. — This variety of mica is much more rare than any
of the others described. While in a few instances it has been
reported as accompanying muscovite in certain granites, as those
of Elba and Schaistausk, its common form of occurrence is in the
coarse pegmatitic veins already described, where it is associated
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SIUCATES. 179
with muscovite, tourm^ines, and other minerals of similar habit.
As a rule it is readily distin<;uished from other micas by its beautiful
peach-blossom pink color, though sometimes colorless and to be
distinguished only by the lithia reaction.' The folia are thicker
than those of muscovite and of small size, the usual form being
that of a scaly granular aggregate. At Auburn, Mame, it is found
both in this form and forming a border a half inch, more or less,
in width about the muscovite folia. The more noted localities in
the United States are Auburn, Androscoggin County; Hebron, Paris,
Rumford, and Norway, Oxford County, Maine, where it is asso-
ciated with beautiful red and green tourmalines and other interest-
ing minerals; Chesterfield, Massachusetts; Haddam, Coimecticut;
the Black Hills, South Dakota; and near San Diego, California.
The most noted foreign locality is Zinnwald, Saxony, where the
mineral occurs in large foliated masses together with quartz form-
ing the gangue minerals of the tin veins. Also found in Moravia.
(See further under Spodumene, p. 200.)
Roscoelite, Vanadium mica. — ^The name roscoelite has been
given to a clove-brown to greenish, micacous mineral occurring
in minute scales, stellate or fan-shaped forms, and of a somewhat
doubtfid chemical formida. It may be mentioned here as a possible
future source of vanadium salts. On the next page are given the
results of two analyses from a recent paper by W. F. Hillebrand,
(1) being of material from Placerville, Colorado, and (2) from
Eldorado County, California.
Occurrence. — The material has been reported as filling cavities in
quartz at the Granite Creek gold mines near Coloma, El Dorado
County, California, and in the Magnolia district of Colorado. More
recendy deposits of some considerable economic importance have
been found near Placerville in San Miguel County, in the last-named
State. The roscoelite is described ' as occurring as an impregna-
tion in the lower bed of what is known as the La Plata sandstone
(Jurassic). The beds at this point are nearly horizontal, the por-
tion carrying the roscoelite occurring in a nearly continuous band
' The mineiat when mobtened with hydrochloric acid and held on a wire in the
flame of a lamp imparU to the flame a brilliant lilhta-red color.
' F. L. Ransome, American Journal of Science, X, August, 1900.
ovGoc^lc
iSo
THE NON-METALUC MIKERALS.
approximately parallel to the bedding planes and varying in thick-
ness from a few inches up to 5 or 6 feet, the vanadiferous portion
being readily distinguished from the prevailing light-buff sand-
stone by the greenish tint imparted by the roscoelite. The vanadif-
erous zone is, however, quite irregular, the roscoelite sometimes
constituting 30 per cent of the mass of the sandstone and from
this fadii^ out to nothing. It is often associated with Camotite
(see p. 332).
JUJALlfSES or ROSCOEUTE, A VANADIUM mcA.
SiO,
TiO,
v.o,
ALO,.
FtO,
CaO
BaO
MgO
K,0
Na-O
HjOatios"
H,0 at los'-joo".
H,0 above 300°. . .
Roicoelite froni
Eldondo
County.Caai-
Vses. — Until within a few years almost the only commercial
use of mica was in the doors or windows of stoves and furnaces,
the peepholes of furnaces and similar situations where transparency
and resistance to heat were essential qualities. To a less extent
it was used in lanterns, and, it is said, in the portholes of naval vessels,
where the vibrations would demolish the less elastic ^ass. In
early days it was used for window panes, and is, in isolated cases^
still so used to some extent. For all these purposes the white
variety muscovite is most suited. For use in stoves and furnaces
the mica is generally split into plates varying from about one-eighth
to one sixty-fourth of an inch in thickness. In preparing these
plates for market the first step is to cut them into suitable
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sizes. Women are frequently employed in this work. The cutter
sits on a special bench which b provided with a huge pair of shears,
one leg of which is firmly fixed to the bench itself, while the movable
leg is within convenient grasp.
There is an enormous waste in the processes of preparation.
One hundred pounds of block mica will scarcely yield more than
about fifteen pounds of the cut material, and sometimes even less.
The proportion varies, of course, with different localities.*
According to J. H. Pratt ^ the North Carolina mines yield from
1 to lo per cent of mica, and of this amount not over lo to 15 per
cent will yield commercial sheet mica. Sheeted blocks will some-
times yield 30 to 40 per cent, and very rarely 75 per cent. Many
of the Western mines do not yield more than 2 or 3 per cent of cut
mica. Sterrett states that the New York mine at Custer, South
Dakota, averages about 6.6 per cent of rough mica, Cirkel states '
that under ordinary circumstances the Canadian phlogopite mines
must yield at least 1,350 pounds of trimmed mica for every 100 tons
of rock moved from depths not exceeding 300 feet, in order to be
profitable. The percentage amounts of sizes of the trimmed mica
is extremely variable, A fairly good average b given as: 50 per
cent of i"x3"; 30 per cent of 2"x3"; 10 per cent of 2"% 4,";
6 per cent of 3" x 5", and 4 per cent of 4" x 6" and over.
Mica being a non-conductor is of value for insulating purposes,
and since the introduction of the present system of generating
electricity there has arisen a considerable demand for it in the con-
struction of dynamos and electric motors. For these purposes
the mica must be smooth and flexible, as well as free from spots
or inequalities of any kind. It is stated that it should be sufficiently
fissile to split into sheets not above three one-hundredths inch in
thickness, and which may be bent without cracking into a circle
of 3 mches diameter. Strips of various dimensions are used in
building up the armatures, the more common sizes being about
I inch wide by 6 or 8 inches long. Muscovite serves the purposes
* Engineering and Mining Journal, LV, 1893. p. 4.
' Mineral Resources of the United States, 1904.
* Mica, Its Occurrence, Exploitation and Uses, p. 46.
jvGooi^lc
182 THE NON-METALLIC MINERALS.
well, but is less used than phlogopite, the latter serving equally
well, and being less desirable for stoves and furnaces. Black mica
would doubtless serve for many purposes, could it be procured
in sheets of sufficient size.
Mica scraps such as until within a few years have been thrown
away as worthless are now utilized by grinding, the product being
used for a variety of purposes, noted below. The material is, as
a rule, ground to five sizes, such as will pass through sieves of 80,
100, 140, 160, and 200 meshes to the inch, respectively. The prices
of tlie ground material vary from 5 to 10 cents a pound according
to sizes. Large quantities of ground mica are used m the manu-
facture of wall paper, in producing the frost effects on Christmas
cards, in stage scenery, and as a powder for the hair, being sold
for the latter purposes under the name of diamond powder. The
so-called French " silver molding " is said to be made from ground
mica. It is also used as a lubricant, and as a non-conductor for
steam and water heating; in the manufacture of door-knobs and
buttons. It is stated further that owing to its elasticity it can be
used as an absorbent for nitroglycerine, rendering explosion by
percussion much less likely to occur. Small amounts of inferior
qualities are also mixed with fertilizers where it is claimed to be
efficacious in retaining moisture. A brilliant and unalterable
mica paint is said to be prepared by first lightly igniting the ground
mica and then boiling in hydrochloric acid, after which it is dried
and mixed with collodion, and applied with a brush. Owing to
the unalterable nature of the material under all ordinaiy conditions,
and the fact that it can be readily colored and still retain its bril-
hancy and transparency, the ground mica is peculiarly fitted for
many forms of decoration. Much of the ground material now
produced is stated to be sent to France.
The chief and indeed only use for lepidohte thus far developed
is in the manufacture of the metal lithium and lithia salts. For
possible uses of roscoelite see under Vanadates.
Prices. — The total value of the cut mica produced annually in
the United States during the past fifteen years has varied from $50,000
to over $360,000, while the value of the imports has varied between
$5,000 and $100,000. During 1901 but 360,000 pounds of cut
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SIUCATES. 183
mka were produced, valued at $98,859, During the same period
there were produced 2,171 tons of scrap mica, valued at $19,719.
Statistics for 1907 show 1,060,182 pounds sheet mica valued at
$349,311, and 3,025 short tons of scrap, valued at $42,800. The
price of the tut mica, it should be stated, varies with the size of
the sheets, the larger naturally bringing the higher price. The
average price of the cut mica, all sizes, is not far from $1 a pound,
while the scrap mica is worth perhaps half a cent a pound. The
dealers' lists, as published, include 193 sizes, varying from ij by
2 inches up to 8 by 10 inches, the prices ranging from 40 cents to
$13 a pound. For electrical work upward of 400 patterns are
called for, the prices varying &om 10 cents to $2.50 a pound.
BIBLIOGRAPHY.
W. C. Kerb. The Mica Veins of North Carolina.
Transactions of tbc American Institute of Mining Enginecra, VIII, 1879, p. 457.
Mekwyn Suith. Miis Mining in India.
Engineering and Mining Journal, LXVIII, 1S99, p. 146.
R. W. Ells. Bulletin on Mim.
Mineral Resources of Canada, 1904.
Fritz Cireel. Mica, Its Occurrence, Exploilalion, and Uses.
Mines Branch, Department of Interior, Canada, 1905.
G. W. COLLES. Mica and the Mica Industry.
Journal of Franklin Institute, CX and CXI, 1905-06.
Ralfb Stokes. India Mica Industry.
The Mining World, XXIV, 1906, pp. 606 and 773.
Douglas Stewiztt. Investiga.iiona Relating to Mica, etc., in 1906.
Bulletin No. 315, U. S. Geologic»l Survey, igo6, p. 400. ■
3. Asbestos.
The name asbestos in its original sense includes only a fibrous
variety of the mineral amphibole; hence it is a normal metasilicate
of calcium and magnesium with usually varying amounts of iron and
manganese, and not infrequently smaller quantities of the alkalies.
As is well known, the amphiboles crystallize in the monoclinic system
in forms varying from short, stout crystals, like common hornblende,
to long columnar or even fibrous forms, to which the names actinolite,
tremolite, wid asbestos are applied. The word asbestos is derived
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l84 THE NOS-METALUC MINERALS.
from tbe Greek a<r/Se<rTos, signifying incombustible, in allusion to its
fire-proof qualities. The name amianthus was given it by the Greeks
and Romans, the word signifying undeBled, and was applied in
allusion to the fact that cloth made from it could be readily cleansed
by throwing it into the fire. As now used, this term is properly
limited to fibrous varieties of serpentine. Owing to careless usage,
and in part to ignorance, the name asbestos* is now applied to at
least four distinct minerals, having in common only a fibrous struc-
ture and more or less fire- and acid-proof properties. These four
minerals are: First, true asbestos; second, anthophyllite; third,
fibrous serpentine (chrysotile), and, fourth, crocidolite. The true
asbestos is of a white or gray color, sometimes greenish or stained
yellowish by iron oxide. Its fibrous structure is, however, its most
marked characteristic, the entire mass of material as taken from
the parent rock being susceptible of being shredded up into fine
fibers sometimes several feet in length. In the better varieties
the fibers are sufficiently elastic to permit of their being woven into
cloth. Often, however, through the effect of weathering or other
agencies, the fibers are brittle and suitable only for felts and other
non-conducting materials. The shape of an asbestos fiber is, as a
rule, polygonal in outline and of a quite uniform diameter. Often
however, the fibers are splinter-like, running into fine, needle-like
points at the extremity. The diameters of these fibers are quite
variable, and, indeed, in many instances there seems no practical
limit to the shredding. Down to a diameter of 0.002 mm. and some-
times to even 0,001 mm. the fibers retain their uniform diameter and
polygonal outlines. Beyond this, however, they become splinter-
like and irregular as above noted.
The mineral anthophyllite, like amphibole, occurs in both mas-
sive, platy, and fibrous forms, the latter being to the imaided eye
indistinguishable from the true asbestos.
Chemically this mineral is a normal metasilicate of magnesia of the
formula CMg,Fe)Si03, differing, it will be observed, from asbest6s
> Also spelled asbestus. The lermiiuitioa at seems most desirable when tbe deri-
vation of tbe word b considered.
J, Google
SIUCATES 185
proper in containii^ no appreciable amount of lime. It further
differs in crystallizing in the orthorhombic rather than the mono-
clinic system, a feature which is determinable only with the aid of a
microscope. The shape and size of the fibers are essentially the same
as true asbestos. The fibrous variety of serpentine to which the
name asbestos is commercially given is a hydrated metasilicate of
magnesia of the formula H,Mg,Si,0, with usually a part of the
magnesia replaced by ferrous iron. It differs, it will be observed,
from asbestos and anthophyllite in carrying nearly 14 per cent
of combined water and from the first named in containing no lime.
This mineral is in most cases readily distinguished from either of the
others by its soft, silk-hke fibers and further by the fact that it is
more or less decomposed by acids. As found in nature the material
is of a lively oil-yellow or greenish color, compact and quite hard,
but may be readily reduced to the white, fluffy, fibrous state by
beating, hand-picking, or running between roller; The length of
the fiber is quite variable, rarely exceeding 6 inches, but of very
smooth, uniform diameter and great flexibility.
The mineral crocidolite, although somewhat resembling fibrous
serpentine, belongs properly to the amphibole group. Chemically
it is anhydrous sQicate of iron and soda, the iron existing in both
the sesquioxide and protoxide states. More or less lime and magnesia
may be present as combined impurities. The color varies from lav-
ender-blue to greenish, the fibers being silky like serpentine, but with
a slightly harsh feeling. The composition of representative speci-
mens of these minerals from various sources is given in the accom-
pan3Tng table.* (See pp. 186, 187.)
Mode of occurrence and origin. — Concerning the associations,
occurrence, and origin of the fibrous structure of these minerals
existing literature is strangely silent. It is known that all occur
in regions occupied by the older eruptive and metamorphic rocks.
It is probable that in the fibrous forms the mineral is always secondary,
and in the true (amphibole) asbestos due in part, at least, to shearing
' From Notes on .Asbestos and Asbestifonn Minerals, by George P. Merrill. Pro-
ceedings of the U. S. National Museum, XVIII, 1S95, pp. 381-193.
J, Google
THE NONMETjiLLlC MINERALS.
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i88 THE NON-METALUC MINERALS.
agencies; that is, to movements in the mass of a rock whereby a
mineral undergoing crystallization would be compressed laterally
and drawn out along the line of least resistance. It is even probable
that the structure is but an extreme development of the prismatic
cleavage, due to the shearing forces.
The asbestos of Alberene, in Albemarle County, Virginia, occurs
in thin platy masses along slickensided zones in the so-called soap-
stone (altered pyroxenite) of the region, the fibers always running
parallel with the direction of the movement which has taken place.
The same is true of the asbestos found in the magnetite mines near
Blacksburg, in Cherokee County, South Carolina, where the fibrous
structure is developed only along shear zones. At Alberton, Mary-
land, the fibrous anthophyllite occurs along a slickensided zone be-
tween a schistose actinolite rock and a more massive serpentinous
or talcose rock, which is also presumably an eruptive peridotite or
pyroxenite. The fibration here runs also parallel with the direction
of movement as indicated by the slickensided surfaces.
The Sail Mountain (Georgia) asbestos is anthophyllite, of a
grayish-white color, though often stained by iron oxides. The
entire mass of the material as mined is made up of groups of bundles
of more or less radial fibrous structure, the fibers tending to form
spherical bunches, though, owing to imperfect development caused
by interference in crystallization, the radial structure is obscured
and the mass consists of fibrous sheaves or bundles running in all
directions. As mined, it is said to consist of over 90 per cent of
material which can be utiUzed as fiber. Within an area a little more
than one-half mile square, in the vicinity of Sail Mountain, there are
stated to be six separate masses of this material, each one roughly
elliptical in shape, with their longer axes approximately parallel and
running north 80° east. The country rock is gneiss, and the asbestos
itself is regarded by Diller ' as an altered igneous rock. The
Iwgest mass reported had a length of about 75 feet and a maximum
width of 50 feet. It has been mined to a depth upwards of 50 feet.
The asbestiform serpMitine, as noted elsewhere, occurs in short,
disconnected gash veins which traverse the massive rock of the
' Mineral Resources of the U. S., 1907.
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SILICATES. 1S9
same general nature in every direction. These veins axe short,
rarely more than a few feet in length, and it is impossible that there
should have been any appreciable differential movement between
their walls. The present writer has attempted to account for these
on the assumption that the vein cavities were formed by shrinkage,
and the vein filling by a process of growth of the fibers from the walls
of the cavities inward,'
Localities. — As akeady stated true amphibole asbestos occurs
only in regions of eruptive and metamorphic rocks belonging to the
Archiean and Paleozoic formations. The same is true of anthophyllite.
Fibrous serpentine occurs sporadically with the massive forms of
the same rock which is, so far as known, almost invariably an altered
eruptive,* The three forms are therefore likely to occur in greater
or less abundance in any of the States bordering along the Appa-
lachian system, but are necessarily tacking in the great Interior
Plains regions, recurring once more among the crystalline rocks
of the Western Cordilleras and the Pacific coast. The principal
States from which either the true asbestos or anthophyllite has
been obtained in anything like commercial quantities are Massa-
chusetts, Connecticut, New York, Maryland, Virginia, North Caro-
lina, South Carolina, Georgia, and Alabama, though it has been
reported from other Eastern as well as several of the Western States.
Fibrous serpentine (chrysotile, or amianthus) occurs in small amounts
at Deer Isle, Maine; in northern Vermont; at Easton, Pennsylvania;
Montville, New Jersey; the Grand Cation region of Arizona; in
the Casper Mountains of Wyoming, and in the State of Washing-
ton. It is known also to occur in Newfoundland,
Asbestiform serpentine occurs in Canada, in an mterrupted belt
of serpentinous rocks extending from the Chaudifere River, in Quebec
• On the Forroalion at Veins ot Asbestiform Serpentine. Bulletin of the Geolc^ral
Sodetjr of America, XVI, 1905, p. 133.
'The Montville, N. J., occuirence is evidently an eiception, as is also perhaps
that of the Grand Cafion region. In the Brst-mentioned instance the seipentine
results from the alteration of nodular masses of gray and white pyroxene. The veins
of fibrous material are here, as a rule, roughly parallel to the outer surfaces ot these
nodules. They ate small, and of no commercial value. {See On the Serpentine ot
Montville, N. J. By Geo. P. Merrill, Proc. U. S, National Museum, XI, 1885, pp.
105-111.)
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THE NON-METMLUC MINERALS.
province, southwesterly to the Vermont line, and beyond. The
principal producing points thus far developed are in the Thetford
Fic. 34. — S«ctba of asbestos-bearing rocks, Thetford, Canada.
[After Cirlcel: Asbestos, Its Ocmneoce, Exploitation, and Uses.]
and Black Lake area, which begins at a point between the towns of
St Joseph and St. Francis, and extends southwesterly into Broughton,
FlO. 35. — Map showing serpentine areas in Eastern Townships of Quebec.
[After Cirltel: Asbestos, Its Occurrence, Eitpbitation, and Uses.]
Thetford, Coleraine, Wolfestown and Ham, A second area begins
at Danville and extends through Brompton, Oxford, Bolton, and
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SILICATES.
'9*
Potton to the Vermont line. This area has as yet been productive
only at Danville. A third area occurs on the Gasptf Peninsula.
At Thetford the serpentine occurs in a series of apparently discon-
nected masses of comparatively small extent which are presumably
altered gabbros or peridotites that were intruded into the prevailing
schbts. These serpentinous masses have been in their turn intruded
by dikes of diabase and granite. The fibrous material occurs in
the form of short gash veins, evidently shrinkage cracks, which
traverse the massive rock in all directions. These are at best but
a few inches in width, pinching out to mere knife-like edges, and
of but a few feet in lengtli. The edges of two adjacent veins often
overlap, but are apparently wholly disconnected (see Fig. 36).
They also cut one another
at every conceivable angle.
\'ein5 which do not pinch
out to knife edges are
often split up, or "frayed
out" at the ends, like a
ragged piece of cloth.
They occur at inter\'als
of a few inches to many
feet, the wkler the vein
the greater the intervening fig.. 36.— Vertic;
distance, as a rule. The Bl
vein material is itself of
almost silk -like liber, though the individual fibers rarely extend
from wall to wall, but are interrupted by splinters and granules of
the massive material. Veins of more than 3 or 4 inches in width are
rare, though 6 inches in width has been reported.
The Vermont asbestos is of the same type as the Canadian. It
is found near Eden, in Lamoille County, and the adjacent town of
Lowell, in Orleans Coimty, in the northern part of the State. At
Eden the mines occur in the south face of Belvidere Mountain, where
there b a great mass of serpentine intruded between a micaceous
schbt below and a homblendic schist above. The serpentine
occurs in the form of bold escarpments, and the mining b carried
on whoUy from open cuts. The veins are rarely more than three-
il section «-all of a
ick Lake, Canada.
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iga THE NON-METALLIC MINERALS.
fourths of an inch in width. At Lowell two types of material are
met with, the one with fibers standing practically at right angles with
the walls, as in the localities described, and the other with fibers
parallel to the slickensided faces of joints. This last variety is
much the more brittle, and as it occurs in layers seldom more than
an inch in thickness, is less desirable.
According to Pratt, the serpentine asbestos of the Grand Canon
region is exposed only in the cafion wall in Coconino County, Arizona.
FlO. 37. — Serpemine asbestos in masiive serpentine.
[ U. S. National Museum.]
The material is found in a serpentinized limestone belonging to the
Algonkian series, where, in contact with intrusive sheets of basalt,
the serpentinized areas are almost constant over an area of some
9,000 feet in length, but only from 18 to 24 inches in thickness. The
asbestiform seams are quite regular, varying in width up to 3
inches, the fibers being at times of a most beautiful golden color,
and remarkably soft and silky. The smaller seams yield the highest
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SILICATES. 193
grade of material, but the quality as a whole is very high, as good as
that of Canada, or elsewhere.
The veins lie nearly 5,000 feet below the rim of the Cafion, and
within the area of the National reservation.
The Italian asbestos which finds its way to the American markets
is both of the amphibolic and serpentinous varieties, both being re-
markable for the beautiful long fibers they yield. The amphibolic
variety, the true asbestos, comes from Mont Cenb, and the serpen-
tinous variety from Aosta.
Methods of mining and preparation. — The mining of asbestos is
carried on almost wholly from open cuts and shallow tunnels. Rarely
does it pay to follow the material to any great depth.
In the mining of the Canadian material the rock b blasted out
and the asbestos separated from the inclosing rock by a process
known as "cobbing," whk:h coqsists in breaking away the fibrous
material from the walls of the vein or from other foreign ingredients
by means of hammers.
The cobbed material is separated into grades, according to
quality, which depends upon the loigth, fineness, and flexibility of
the fiber. During 1888 the finest grades brought prices varying from
$So to $110 a ton. The prices at times have gone even higher.
The amphibole asbestos, on the other hand, rarely brings over $20
a ton.
Uses. — The uses of asbestos are manifold, and ever on the
increase. Among the ancient Greeks it was customary to wrap
the bodies of those to be burned in asbestos cloth, that their ashes
might be kept intact. In the eighth century Charlemagne is said
to have used an asbestos tablecloth, which, when the feast was over,
he would throw into the fire, after a time withdrawing it cleaned but
unharmed, greatly to the entertainment of his guests. The most
striking use to which the material is put is the manufacture of fire-
proof cloths for theater curtains, for suits of firemen and others
liable to exposure to great heat. It is also used for packing pistons,
closing joints in cylinder heads, and other fittings where heat, either
dry or from steam and hot water, would shortly destroy a less durable
substance. For this purpose it is used in the form of a yam, or as
millboard. The lower grades, in which the fibers are short or
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194 THE NON-METMLUC MINERALS.
brittle, are made into a felt which, on account of its non-conducting
powers, is utilized in covering steam boilers. It is also ground
and made into cements and paints, the cement being used as a non-
conductor on boilers, and the paint to render wooden structures
less susceptible to fire. In the chemical laboratory the finely fibered,
thoroughly purified asbestos forms an indispensable filtering medium.
For this purpose the true asbestos is preferable to the fibrous serpen-
tine.' In the manufacture of cloth, rope, and other materials where
strength and flexibility of fiber are essential the serpentine asbestos
(chrysotile) is preferable to the amphibobc form, though, owing to its
hydrous condition, it is, in reality less fire-proof.
Within a few years it has been found that the massive material
previously considered as waste at the mines could, by proper treat-
ment, be reduced to a fibrous pulp admirably adapted for a wall
plaster, and similar uses. This material is known under the com-
mercial name of asbestic.
The chief use of asbestos is based upon its highly refractory or
non-combustible nature. The popular impression that it is a non-
conductor of heat is, according to Professor Donald, erroneous, the
non-conducting character of the prepared material being due rather
to its porous nature than to the physical properties of the mineral
itself.* Owing to the comparatively high price of asbestos, it is, in
the manufacture of the so-called non-conducting materials, largely
admixed with plaster of Paris, powdered limestone, dolomite, mag-
nesite, diatomaceous earth, or carbonaceous matter, as hair, paper,
sawdust, etc. With the possible exception of the magnesite (carbon-
ate of magnesia) these are all less effective than the asbestos, and
deteriorate as well as cheapen the manufactured article. The
following table will serve to convey some idea of the relative portions
of the various materials used as non-conducting pipe coverings.
* Prof. A. H. Chester: Some Misconceptioiu Conceming Aabcstoi. Eogmeeriiig
nnd Mining Journal, LV, 1893, p. 531,
' The Mineral Industry, II, 1893, p. 4.
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Asbestos sponge, molded:
Plaster of Faiii
Fibrous asbeslos ....
Eire-felt sectioual coveriag;
Asbestos
Carbonaceous matter (hair, papor, sawdust el
Magnesia sectional covering;
Carbonate of magnesia. . .
F%rous asbestos
Asbestos-sponge cement felting:
Pondeicd limestone
Plaster of Paris.
Asbestos .....
Foeiil meal:
Insoluble silicate..
Carbonaceous matter (hair, paper, sawdust, c
Soluble mineral matter
Moisture
At Phillipsburg, New Jersey, and the adjoining town of Easton,
Pennsylvania, a mineral pidp is prepared from a metamorphic rock
of somewhat mixed composition, occurring in the immediate vicinity.
As quarried, the material is hard, compact and massive, though
with a somewhat fibrous structure, and of a gray white or greenish
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196
THE NON-METALLIC MINERALS.
color, the variatbn in color being due to the different stages of
alteration which the rock has undergone. The least altered material,
of a white or gray color, consbts essentially of the mineral tremolite,
which, as the writer has elsewhere ^ noted, undergoes alteration into
serpentine, giving rise to the green color above noted. According to
Professor F. P. Peck,^ the tremolite at times also undergoes an altera-
tion into talc. The unaltered tremolite has the following composition :
Conitiuents.
Per cone
*5
S
w
41
W-40
The massive serp^tinous rock resulting from its alteration, and
which is used in the manufacture of the better grades of pulp, has
die following composition :
Percent.
4S.>3
1 -^^
".30
99.96
The material is groimd between French buhrstones and is used
in the manufacture of rubber goods and as a filler in paper manu-
facture. The ground pulp, at the mills, was quoted in 1904 as worth
$6.50 per ton.
' Proceedings U. S. National Museum, XII, 1890, p. 599.
> Annual Report SUtc Geologist of New Jersey, 19*4. P- 1^3-
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SIUCATES. 197
The annual amount of asbestos of all kinds produced in the
United States varies from 600 to 1,000 tons, valued at about $15 per
ton. Some 30,000 tons of asbestos and asbestic are produced by the
Canadian mines, a considerable proportion of which finds its way into
American markets.
BIBUOGRAPHY.
A. LivERSUXSE. Minerals o[ New Souih Wales, i8S8, p. i8o. Gins list of lonlhin.
J. T. Donald. Asbestoe in Canada. ,
The Mineral Industry, I, 1S91, p. 30; also II, iSgj, p. 37.
L. A. Klein. Notes on the Asbestos Industry of Canada.
The Mineral Industry, I, 189a, p. 3a,
Rttoou Maxloch. Asbestos in South America.
Engineering and Mining Journal, LVIII, 1894, p. 371.
C, E. Willis. The Asbestos Fields of Porl-au-Port, Newfoundland.
Engineering and Mining Journal, LVIII, 1894, p. 5S6.
Gbokge p. Mersill. Notes on Asbestos and Other AsbesUfoim Mlnerall.
Proceedings of the U. S. National Museum, XVIII, 1S95, p. 381.
H. Nellzs Thoupson. Asbestos Mblng and Dressing at Thetford.
The Journal of the Federated Canadian Mining Institute, 1897, II, p. 173.
See alao the Canadian Mining Review, XVI, 1897, p. 136.
Robert H. Jones. Asbestos and Asbestic: Their Properties, Occurrence, and Use.
London, 1S97, pp. 36S.
J. F. Keup. Notes on the occunence of Asbestos in Lamoille and Orleans counties
VeimonL
Mineral Resources of the United States for 1900 et seq.
Georce p. Messill. On the Formation of Veins of Asbestiform Serpentine.
Bulletin of the Geological Society of America, XVI, 1905, p. 113.
F. CiRSEL. Asbestos, Its Occunence, Exploitation, and Uses.
4. GARNET.
The chemical composition of the various minerals of the garnet
group is somewhat variable, though all are essentially silicates of
alumina, lime, iron, or magnesia. The more common types are
the lime-alumina garnet grossuiarile, and the iron-alumina garnet
alamandiie. Other varieties of value as minerals or as gems are
Pyrope, spessartite, andradite, bredbergile, and uvarovite.
The ordinary form of the garnet is the regular 12- or 34-sided
solid, the dodecahedron and trapezodedron, as shown in F^. 38.
The color is dull red or brown, though in the rarer forms yellow,
green, and white. Hardness from 6.5 to 7.5 of the scale.
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198 THE NON-METALLIC MINERALS.
Occurrence. — Garnets occur mainly in metaniorphic siliceous
rocks, such as the mica schists and gneisses, and though sometimes
found in limestones and in eruptive rocks, are rarely sufficiently
abundant to be of economic importance. In the gneisses and schists,
however, they at times preponderate over every other constituent,
varying from sizes smaller than a pin's head to masses of 100 pounds'
weight, or more.
The most important garnet-producing regions pf the United
States are Roxbury, Connecticut, Warren County, New York, and
Delaware County, Pennsylvania. At the first-named locality, the
garnets occur in a mica schist; in New York they are found in
pKt. 38. — Outlines of garnet crystals.
laminated pockets scattered through beds of a veiy compact horn-
blende feldspar rock, the size of the pockets ranging from 5 or 6
inches in diameter to such as will yield 1,000 pounds or more. In
the Delaware County localities the garnets occur in aggregates of
small crystals in a quartzose gneiss.'
One of the most noted gamet regions of the world is that near
Prague, Bohemia. According to G. F. Kunz,* the garnets of the
pyrope variety are indigenous to an eruptive rock now changed to
serpentine, and the mineral is found "loose in the soil or in the
lower part of the diluvium, or embedded in a serpentine rock. . . .
In mii'in;.^ the earth is cut down in banks and only the lower layer
mo\i,l, and the garnets are separated by washing. The earth
'The ^:inMal Industry, V, 1896.
'Transactions at ihe American Institute of Mining Engineeis, XXI, 189a, p. 341.
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SILICATES. 199
is first dry-sifted and then washed in a small jig consisting of a
sieve moved back and forth in a tank of water."
Accordii^ to Mr. D. B. Sterrett, the garnets at Roxbury, noted
above, occur in the form of dodecahedrons of all sizes up to an inch
and a half in diameter, embedded in a mica schist.
The present quarry is situated upon a hilltop some three miles
outside of the town of Roxbury. Mining is done wholly by open
cuts. The rock is blasted out by dynamite and broken into masses
suitable for handUng, which are then raised from the quarry, dumped
into a gravity car, and run to a crushing mill. The schist is soft,
crushii^ easily, the garnets coming out, in large part, free from
the matrix and unbroken.
From the crusher pieces of all sizes up to a hen's egg fall through
a chute and are scattered evenly over a broad belt, some 2 feet
in width and 12 or more in length, over which small streams
of water are kept playing in order to settle the dust and cleanse
the garnets. On either side of this belt men are employed to pick
out the garnets, which are placed upon a small belt above moving
in the same direction. This carries them to the storing bins, where
they are run into sacks of 100 pounds' weight each and shipped.
The waste at the quany is very great, amounting, it is estimated,
to from one-half to three-fourths of the entire amount mined.
Uses. — Aside from their uses in the cheaper forms of jewelry,
garnets aje used for abrading purposes and mainly as a sand for
sawing and grinding stone or for making sandpaper. The material
is of less value than corundum or emery, owing to its inferior hard-
ness. The commerciai value is variable, but as prepared for market
it is about 3 cents a pound.
S- ZIRCON.
This is a silicate of zirconium, ZrSiO,, = silica, 32.8 per cent;
zirconia, 67.3 per cent; specific gravity, 4.68 to 4.7; hardness, 7.5;
colorless, grayish, pale yellow to brown or reddish brown. Ordi-
narily in the form of square prisms {Fig. 39).
Zircon is a common constituent of the older eruptives like granite
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Fto. 39. — Oudines of liicoa oysMls. .
aoo THE ms-METALUC MINERALS.
and syenite, and also occurs in granular limestone, gneiss, and
the schists. It is so abundant in the elaeolite syenites of Southern
Norway as to have given rise to the varietal name Zircon syenite.
Although widespread as a rock constituent it has been reported
in but few instances in sufficient abundance to make it of commercial
value. Being hard and very durable it resists to the last ordinary
atmospheric agencies, and hence is to be found in beds of sand,
^^^ gravel, and other debris resulting from
^/y--^^ y''^ V^. *^^ decomposition of rocks in which it
V'^ /- V^ primarily occurs. It has thus been
reported as found in the alluvial sands
in Ceylon, in the gold sands of the
Ural Mountains, Australia, and other
places. In the United States it occurs
in considerable abundance in the ebeo-
Ijte syenite of Litchfield, Maine, and
is also found in other States bordering
along the Appalachian Mountains. The most noted localities are in
Henderson and Buncombe counties in North Carolina, whence several
tons have been mined during the past few years from granite debris.
Uses. — See under Monazite, p. 298.
6. SPODtJUENE ANB FETALITE.
Spodnmene. — This is an aluminum-lithium silicate of the formula
LiAl(SiO,)„ = silica, 64.5 per cent; alumina, 27.4 per cent; lithia,
8.4 per cent; in nature more or less impure through the presence of
small amounts of ferrous oxide, lime, magnesia, potash, and soda.
Luster, vitreous to pearly; colors, white, gray, greenish, yellow, and
amethystine purple, transparent to translucent. Usual form that of
flattened prismatic crystals, with easy cleavages parallel with the
faces of the prism. Also in massive forms. Crystals sometimes
of enormous aze, as noted below.
Mode oj occurrence. — Spodumene occurs commonly in the coarse
granitic veins associated with other lithia minerals, together with
tourmaline, beryls, quartz, feldspar, and mica. The chief localities
as given by Dana are as below:
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Fig. 1.— Large Spodumene CrysUls in Granitic Rock, Etta Mine, Black Hills,
South Dakota.
[From photograph by E. O. Hovey.]
Flc. 1. — Soapstone Quarry, Nelson County, VirRinii
[After Thos. Watson, Mineral Resourcesof Virginia.
PLATE XVIII. GoOqIc
[Facing page »oo:\ O
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" In the United States, in granite at Goshen, Massachusetts,
associated at one locality with blue tourmaline and beryl; also
at Chesterfield, Chester, Huntington (formerly Norwich), and
Sterling, Massachusetts; at Windham, Maine, with garnet and
stauroUte; at Peru with beryl, triphyUte, petalite; at Paris, in
Oxford County; at Winchester, New Hampshire; at Brookfield,
Connecticut, in small grayish or greenish-white individuals looking
like feldspar; at Branchville, Connecticut, in a vein of pegmatite,
with lithiophilite, uraninite, several manganesian phosphates; near
Stony Point, Alexander County, North Carolina, the variety hid-
denite in cavities in a gneissoid rock with beryl (emerald), monazite,
rutile, allanite, quartz, mica; near BaLground, Cherokee County,
Georgia; in South Dakota at the Etta tin mme in Pennington County,
in immeaise crystals. At Huntington, Massachusetts, it is associated
with triphylite, mica, beryl, and albite."
At the Etta tin mine, in the Black Hills of South Dakota, the
mineral occurs, according to W, P. Blake, in sizes the magnitude of
which exceeds aU records. Crystalline masses extend across the
face of the open cut from 3 to 6 feet in length and from a few inches
to 12 and 18 inches in diameter. The g^antic crystals preserve the
cleavage characterbtics and show the common prismatic planes.
The color is lighter and b without the delicate creamy-pink hue of the
specimens from Massachusetts. It b very hard, compact, and tough
and b difficult to break across the grain. Some of the fragments are
translucent. See (Plate XVIII.)
The chief foreign localities of spodumene are Ut6 in Sddermanland,
Sweden, where it is associated with magnetic-iron ore, tourmalines,
quartz, and feldspar, near Sterzing and Lisens, in Tyrol; embedded
in granite at Killiney Bay near Dublin, and at Peterhead. Scotland.
Uses. — Spodumene and the lithia-mica lepidolite are used in
the manufacture of lithia salts, although the industry is not yet
one of great importance. The price of the crude material varies
with the percentage of lithium, which as noted is greatest in the first-
named mineral. During the year 1901 the prices ranged from $1 1.00
to $40.00 per ton. the total production for the year being but 1,750
tons, derived mainly from California and in the form of lepidolite.
Petalite, another lithium-aluminum silicate containing 3.5 to
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20a THE JJON-MET^LUC MNERALS.
5 per cent lilhia occurs associated with lepidolite, tourmaline, and
spodumene in an iron mine at Utd, Sweden, with spodumene and
albite at Pern, Maine, and with scapoUte at Bolton, Massachusetts.
7. lazurite; lapis lazuli; or native ultramarine.
Composition essentially Na,(NaS,, Al)AljSijOu, = silica, 31.7 per
cent; alumina, 26.9 per cent; soda, 27.3 per cent; sulphur, 16.9
per cent; hardness, 5.5; specific gravity, 2.38 to 2.45. Color, rich
azure-violet or greenish blue, translucent to opaque. The ordinary
lapis lazuh is not a simple mineral as given above, but a mixture
of lazurite, hauynite, and various other minerals.
The followii^ analyses quoted from Dana serve to show the
heterogeneous character of the material as found:
Loulitio.
i,s-
^iaisr-
Ferric
^•:
ssa.
Water.
H,0.
^^.
Ori nt
45-33
4054
4S-7*
12-33
43-«3
»S-34
o!86
1.30
"356
"43
"-S4
0-35
3.31
Andes
4.3*
Occurrence. — The localities are mostly foreign. The ultramarine
reported not long ance as occurring near Silver City, New Mexico,
has been shown by R. L. Packard to be a magnesian silicate.
Mexico, Chile, Siberia, India, and Persia are the chief sources.
The following regarding the Indian localities is taken from Ball's
Geolc^ of India, Part III.
The lapis lazuli sold in Kandahar is brought from Sadmoneir
and Bijour, where it is said to occur in masses and nodules embedded
in other rocks. It is also said to have been found at Hazara, and
in Khelat Several writers speak of its occurrence in Beluchistan,
but possibly this may be due to some confusion in names. Beyond '
a question it does exist in Badaksham, the mines south of Firgamu,
in the Kokcha valley, having beai described by Wood in the narra-
tive of his journey to the Oxus.
The entrance to the mines is on the face of the mountain at an
elevation of about 1,500 feet above the level of the stream. The
country rocks are veined, black and white limestones. The principal
mine as represented in elevation pursues a somewhat serpentine
ovGoO'^lc
SILICATES. 30$
direction. The shaft by which one descmds to the gallery is about
lo feet square, and 30 paces long, with a gentle descent, and is
unsupported by pillars. Fires are used to soften the rock and cause
it to crack; on being hammered it comes off in flakes, and when the
precious stone is disclosed a groove is picked round it, and together
with the portion of the matrix it is pried out by means of crowbars.
Three varieties are distinguished by the miners, the nili, or indigo
colored, the asmani, or sky-blue, and the sabzi, or grera. The labor
is compulsory, and mining was only practiced in the winter. Ac-
cording to Wood, these mines and also those for rubies had not been
worked for years, as they had ceased to be profitable. Formerly the
produce from these mines, which must have been considerable, was
exported principally to Bokhara and China, whence a portion foimd
its way to Europe.
Marco Polo states that the azure found here was the finest in the
world, and that it occurred in a vein. The Yamgan tract, in which
the mines were situated, contained many other mines, and doubtless
Tavemier referred to it when he spoke of the territory of a Raja
beyond Kashmir and toward Thibet, where there were three moun-
tains close to one another, one of which produced gold, another
gratuUs (garnets, or rather balas rubies), and the third lapis lazuli.
A small quantity of the mineral is said to be imix>rted into the
Punjab from Kashgar, and a mine is reported to exist near the
source of the Koultouk, a river which falls into Lake Baikal.
Uses. — Ultramarine for coloring purposes has in modem times
lost much of its value, owing to the discovery by M. Guimet in
1828 of an artificial substitute. Formerly it was much used as a
pigment, being preferred by artists in consequence of its possessing
greater purity and clearness of tint. According to Ball,' the artificial
substitute is now commonly sold in the bazars of India under the
same name, lajward, for about 4 rupees a seer, while at Kandahar
in the year 1841, according to Captain Hutton, the true lajward,
which was used for house painting and book illuminating, was sold,
when purified, at from 80 to 100 rupees a seer. Mr, Emanuel
states that the value of the stone itself, when of good color, varies,
according to size, from 10 to 50 shillings an ounce. In Europe the
' Geology of India, III, p. 53S.
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a04 THE NON-METALLIC MINERAIS.
refuse in the manufacture is calcined, and affords delicate gray
pigments, which are known as ultramarine ash.
Lajward is prescribed internally as a medicine by native phy-
sicians; it has been applied externally to ulcers. That it possesses
any real therapeutic powers is, of course, doubtful.
Although no longer a source of any considerable amount of the .
ultramarine of commerce, the compact varieties of the mineral, such
as that from Persia, are "highly esteemed for the manufacture of
mosaics, vases, and other small ornaments.
8. allanite; orthite.
This is a cerium epidote of the formula HR"R'",Si,Oi„ in which
R" may be either calcium or iron {or both) and R"' aluminum, iron
cerium, didymium, or lanthanum. The analyses given below are
selected from Dana's Mineralogy as showing variation in the com-
position sufficient for present purposes:
Silica (SiOJ
Thoria (ThO.)
Alumina (A1,0,)
Iron scsquioxide (FtO,)
Cerium sesquioiide {Cefi^
Didymium sesquioxide (t)i,0.) .
Lanthanum sesquloxide (La,0^
Yttrium sesquiowdc (YjOJ
Etbinum sesquioride (Er,0,) ...
Iron protoiide (FeO)
ManganeEC (MnO)
Lime (CaO)
Magnesia (MgO)
Potash (K,0)
Soda (Na,0)
Water (Kfi)
9.89'
Trace.
(I) HitWrti. Norway: <in Vtwrby, Sweden: (lH) NduD Couaty. Virginia.
When in crystals often in long slender nail-like forms (ordiite) ;
also massive and in embedded granules. Color, pitch-black, brown-
ish, and yellow. Britde, Hardness, 5.5 to 6. Specific gravity, 3.5
to 4.2. Before the blowpipe it fuses and swells up to a dark, slaggy,
magnetic glass.
Localities and mode of occurrence. — The more common occur-
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SIUCATES.
205
rence is in the form of small, acicular crystals as an original con-
stituent in granitic rocks. It also occurs in white limestone, asso-
ciated with magnetic-iron ore, and in igneous rocks as andesite, diorite,
and rhyolite. At the Cook Iron Mines, near Port Henry, New York,
it is reported as occurring in great abundance and in ciystab of
extraordinary size, in a gangue of quartz and orthoclase.
The variety orthite occurs in forms closely simulating rusty
nails in the granitic rock about Brunswick, Maine. In Arendal,
Norway, it is found in massive forms. At Finbo, near Falun,
Sweden, in acicular cij'stals a foot or more in length. In Amherst
and Fauquier counties, Virginia, it occurs in lai^e masses, as it
also does near Bethany Church, Iredell County, North Carolina,
and Llano County, Te.\as. At Balsam Gap, Buncombe Count)',
North Carolina, it occurs in slender crystals 6 to 12 inches long and
in crystalline masses, in a granitic vein and under similar conditions
at the Buchanan and Wiseman mines in Mitchell County.
Use&. — See under Monazite, p. 307.
9. GADOLINITE.
This is a basic orthosiUcate of yttrium, iron, and glucinum,
though with frequently varying amounts of didymium, lanthanum,
etc. The formula as given by Dana is GliFeYjSijO,o, = silica,
23.9 per cent; yttrium oxides, 51.8 per cent; iron protoxide, 14.3
per cent, and glucina, 10 per cent. Actual analyses yielded results
as below:
I.
SiUca (SiO,) 14. 15
Thoiia (ThO,)
Yttrium sesquioride (VjO,)
Cerium sesquioride (Ce.O,)
Didymium scsquioxide (DijO.)
Lanthanum scsquioxide (Lik,0,}
Iron scsquioxide (Fe.O,)
Iron protoxide (FeO)
Berylmm (Glucina) protoxide (BeO) .
Lime (CaO)
■'7
45-56
CI) YtWby. new Stwlchdm. Sweden; (II) L
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2o6 THE NON-METMLLIC MINERALS.
The mineral is sometimes found in form of rough and coarse
crj'stals, but more commonly in amorphous, glassy forms. Hard-
ness, 6.5 to 7; specific gravity, 4 to 4,47. Color, brown, black, and
greenish black, usually translucent in thin splinters and of a grass-
green to olive-green color by transmitted light. No true cleavage;
fracture conchoidal or splinterj' like glass, and with a vitreous or
somewhat greasy luster. Through oxidation and hydration the
mineral becomes opaque, brown, and earthy. Hence masses are
not infrequently found consisting of the normal glassy gadolinite
enveloped in a brown-red crust of oxidation products. On casual
inspection the mineral closely reembles samarskite and the dark,
opaque varieties of orthite, but is easily distinguished from the
fact that before the blowpipe it glows brightly for a moment and
then swells up, cracks open, and becomes greenish without fusing.
Some varieties (the normal anisotropic forms) swell up into cauli-
flower-like forms and fuse to a whitish mass. Like orthite, it gives
a jelly when the powdered mineral is boiled in hydrochloric acid.
LocalUies and mode oj occurrence. — The mineral occurs mainly
in coarse pegmatitic veins associated with allanite and other allied
minerals. The principal locality in the United States thus far
described is some five miles south of Bluffton on the west bank
of the Colorado River, in Llano County, Texas, The region is
described ' as occupied by Archiean rocks with granite, and occasional
cappings of limestone.
A coarse deep- red granite is the most abundant, and is cut by
numerous extensive veins of quartz and feldspar which carry the
gadolinite, in pockety masses, and the other minerals mentioned.
Most of the mineral thus far found is altered into the brown-red
waxy material noted above and occurs in the form of masses weir-
ing half a pound and upward. One "huge pointed mass, in reality
a crystal, weighed fully 60 pounds"; another, 42 pounds. One
of the earliest opened pockets yielded some 500 kilos (i too pounds)
of the mineral.
Of the foreign localities those of Kirarfvet, Broddbo, and Finbo,
■ American Journal ot Science, XXXVIIl, 1889, p. i^^. See also Bulletin No. 340,
U. S. Geologital Survey, 1908, pp. j86-2^.
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SIUCATBS.
307
near Falun, Sweden, and at Ytterby, near Stockholm, are important,
the mineral here occurring in the form of rounded masses embedded
in a coarse granite. On the island of Hittero, in the Flecke fiord.
Southern Norway, crystals sometimes four indies across have been
obtained.
Uses. — See under Monazite, p. 307.
rO. CERITE.
This is a silicate of the metals of the cerium group and of a com-
plex and doubtful formula. The analyses below, taken from Dana's
System of Mineralogy, will serve to show the varying character
of the mineral.
Silica (SiOp
Cerium onde (Ce.O,) . . . .
Didymium oxide (Di,0^. .
Iron oride (FeO) .
Alumina (Al,0,) .
Lime (CaO)
Water (H,0)
5-7'
35-37
18.18
33-2S
34.60
3-18
The mineral occurs in gneiss and mica schist, and is of s pre-
vailing pink to gray color.
Uses. — See under Monazite, p. 307.
II. RHODONITE.
This is a metasilicate of manganese of the formula MnSiO,,
—silica, 45.9 per cent; manganese protoxide, 54.1. As a rule,
iron, calcium, or zinc replaces a part of the manganese. The pre-
vailing form of the mineral when in crystals is that of rough, tabular,
or elongated prisms with rounded edges. It is also common in
massive highly cleavable forms, and in disseminated granules.
Rarely, as in the Ekaterinburg district of Russia, it occurs in massive
forms suitable for ornamental work. Color, brownish red, flesh-
red, and pink; sometimes rose-red. Hardness, 5.5 to 6.5. Specific
gravity, 3.4 to 3.68.
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ao8 THE NON-MET^LUC MINERALS.
On exposure the mineral undergoes oxidation, becoming coated
with a black film and giving rise thus to indefinite admixtures of
silicate, oxides, and carbonates of manganese.
The mineral occurs in abundance associated with the iron ores
of Wermland, Sweden, and at other localities in Europe; in Ekaterin-
burg, Russia, as above noted, A vein of the massive material was
discovered some years ago, near Waits River, Vermont, and it has
been reported as occurring near Sitka, Alaska. The zinciferous
variety associated with the zinc ores in granular limestones of Sussex
County, New Jersey, is known as fowlerite.
So far as the writer has information, rhodonite has as yet little
commercial value, excepting as an ornamental stone. To some
extent it has been utilized in glazing pottery and as a flux in smelt-
ing furnaces.
13. steatite; TALC; AND SOAPSTONE.
Steatite, or talc, is a soft micaceous mineral of the formula
H2Mg3Si40i2, and consisting when pure of 63.5 per cent of silica,
31.7 per cent of magnesia, and 4,8 per cent of water. Its most
striking characteristics are its softness, which is such that it tan be
readily cut with a knife or even with the thumb nail, and soapy
feeling, there being an entire absence of anything like grit. The
prevailing colors are white or gray and apple-green. Several varietal
forms are recognized ; the name talc a as rule being applied to the dis-
tinctly foUaceous or micaceous variety, while that of steatite is re-
served for the compact cryptocrystalline to coarsely granular
forms.
PyraUolite and rensselaerite are names given to varietal forms of
talc resulting from the alteration of hornblende or pyroxene. Such
forms are found in various portions of northern New York, Canada,
and Fniland. According to Dana, a part of the so-called agalmatolite
used by the Chinese is steatite.
The name soapstone is given to dark-gray and greenish talcose
rocks, which are soft enough to be readily cut with a knife, and
which have a pronounced soapy or greasy feeling; hence the name.
Such rocks are commonly stated in text-books to be compact forms
ovGoO'^lc
SILICATES. 909
of Steatite, or talc, but as the writer has elsewhere pointed out,' and
as shown by the analyses here given, few of them are even approx-
imately pure foims of this mineral, but all contain varying propor-
tions of chlorite, mica, and trcmohte, together with perhaps unaltered
residuals of pyroxene, granules of iron ore, iron pyrites, quartz,
and, in seams and veins, calcite and magnesian carbonates.
Composition. — The varying composition of talc is shown in
the series of analyses given below:
LonEty.
KO.. |aW)»| P«0.
MgO
arf>
UoO
N.rf)
K,0
H^.
Total!.
fi^tt'Mi^; N.'c^^u^: ; :
60. so
61. ID
61.3s
6.. 8s
60.60
::;:
v.v.
Hi'
-s
V6.
o.to
Not
deter.
■d.
loo.ja
i.So
...»
The following analyses of soapstone have been made in the
laboratory of the U. S. National Museum:
ANALVSES OP
MAPS'
rONE.
IxMahtr. SiO,.
Ufi^
FeO.
MgO
a>o.
UnO.
Na.O
K^.
H^.
TotaU.
6.08
.1:11
1-11
).6j
i;i
a^-jo
Trace
0.1.
1
'S:li
Guilford Co.. North CaroliM. ^o.oj
ZS
0..,
Occurrence and origin. — ^Talc in all its forms is presumably
always a secondary mineral, a product of alteration of other mag-
nesian silicates. If resulting from the alteration of a pure eostatite,
the process might be illustrated as follows; 4(MgSi) Oj2 + H2O +
<;02=H3Mg8Si40i3 + MgC03, or, if from tremolite, as follows;
CaMgsSiiOia+HaO+COa-HaMgaSi^Oja+CaCOa. In the large
majority of cases it is safe to assume that the alteration is from min-
erals carrying more or less alumina and iron, in which case the latter
may separate out as an oxide or may remain, replacing a pordon of
■ Rocks, Rockweathering, and Soils, ad ed., p. 95.
ovGoo'^lc
aro THE NON-MET A LUC MINERALS.
the lime or magnesia, in any case a less pure- variety of talc
resulting.
New York. — Talc in quantities sufficient to be of commercial
importance occurs in beds intercalated in schistose Azoic limestones
in the towns of Edwards and Fowler, near Gouvemeur in St. Law-
rence County, The beds dip with the inclosing rock at a h%h angle,
the individual "veins" varying from a few inches to 20 feet in width.
The mineral, which is regarded by Smyth ^ as an alteration product
of schistose aggregates of enstatite, or perhaps tremolite, is mainly
in the form known as agalite and rensselaerite, the one a smooth,
fibrous variety and the other foliated and lamellar, either being of a
beautiful white - color. Masses of unaltered tremolite still occur
imbedded in the tak, which also at times carries a small amount of
quartz. These are the largest and most extensively worked deposits
at present known within the limits of the United States.
Virginia. — Numerous deposits of talc occur in Fairfax County,
Virginia, the material being invariably associated with lenses of
dioritic or gabbroic rock in such a manner as to indicate that they
originated through the alteration of the more basic, non-feldspathic
portions of these intrusives. The mineral is mainly in schistose and
somewhat fibrous form and is found in very indeiinitely outlined
lenses extending with their longer axes in a northeast-southwest
direction conforming closely with the general strike and dip of the
inclosing rock. The lenses or pockets of commercial material are
of comparatively limited extent, but a few feet in width, though they
may be reaching to a depth beyond practice mining. The bodies
of good, gritless material wedge out, often quite abruptly, and be-
come interleaved with harder, amphibolic and chloritic minerals,
wholly without discemable law or system. Small cross veins some-
times occur, which are filled with light-green, foliated talc. Such
Me, however, too small to be taken into account in working.
The mining is carried on by a system of comparatively shallow
open trenches which are abandoned when through the presence of
water or deterioration of product they became unprofitable. The
material found near Wiehle and Hunter's Station is used largely in
foundry work.
' Fifteenth Annual Report of the State Geologist of New York, 1895.
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The Carolinas. — In western North Carolina and northern Georgia,
particularly in Cherokee and Swain counties in the first-named State,
and in the Cohutta Mountains of Murray County in the last, are
numerous beds of very clean white or greenish fibrous talc occurring
in part, at least, in connection with the marble beds. Some of the
material is soft, white, and almost translucent, while other is tough
and semi-translucent, horn-like. The beds are mostly very irregular
in extent as well as in quality of material.
According to Dr. Pratt the talc formation begins in Swain County
about six miles east of the Valley River Mountains, following up the
valley of the Nantehala to near the Macon County line, whence it
ascends Nelson Creek ravine, crossing the mountain at Red Marble
Gap. Entering Cherokee County it then follows Valley River, cross-
ing it and the Hiawassee near Muiphy and following thence the
Nottely River Valley into Geoigia. The country rock of the talc
region is mainly marble and quartzite, bordered by gneiss and
crystalline schists, the talc itself occurring in connection with the
marble and lyir^ for the most part directly between the marble
and quartzite, but sometimes inclosed wholly in the marble. The
material is found in lenticular masses and is of good quality only
where the beds have been protected by the capping of quartzite;
elsewhere it is more or less stained by iron oxides, and otherwise
injured. There is a considerable variation in the character of
the talc throughout the region. To the east of Red Marble Gap
it is of a bluish-white color and much of it sufficiently compact to
allow of its being cut and used for slate pencils; that to the west is
of a pale greenish-white to bluish-white color, and more fibrous
and foliated. All the varieties are regarded by Pratt as alteration
products of tremolite.
Soapstone occurs mainly associated with the older crystalline
rocks and in some cases is undoubtedly an altered eruptive; in others
there is a possibility of its being a product of metamorphism of mag-
nesian sedimentaries. The principal beds now known lie in the
Appalachian regions of the eastern United States, though others have
recendy been found in California, and there is no reason for supposing
that many more may not exist in the Rocky Mountain regions. The
beds, if such they can be called, are not extensive, as a rule, but occur
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2ia THE NON-METALLIC MINERALS.
in lenticular masses of uncertain age intercalated with other mag-
nesian and homblendic or micaceous rocks frequently more or less
admixed with serpentine. The rock, like serpentine, is traversed
by bad seams and joints, and the opening of any new deposit is
always attended with more or less risk, as there is no guarantee
that sound blocks of suflacient size to be of value will ever be ob-
tainable.
LocalUies. — An extensive bed of fine quality soapstone was dis-
covered as early as 1794 at Francestown, New Hampshire. This
was worked as early as 1802, and up to 1867 some 5,500 tons had
been quarried and sold. Other beds, constituting a part of the same
formation, occur in Weare, Warner, Canterbury, and Richmond,
in the same State. All of these have been operated to a greater
or less extent.
Fine beds of the stone also occur in the town of Orford, and
an important quany was opened as early as 1855 in Haverhill, but
it has not been worked continuously.
At least sixty beds of soapstone are stated ' to occur in Vermont,
mosdy located along the east side of the Green Mountain range,
and extending nearly the entire length of the State. The rock
occurs associated with serpentine and hornblende, and the beds,
as a rule, are not continuous for any distance, but have a great thick-
ness in comparison with their length. Several isolated outcrops may
occur on the same line of strata, perhaps miles apart, in many cases
alternating with beds of dolomitic limestone.
Beds occur in the towns of Readsboro, Marlboro, New Fane,
Windham, Townsend, Athens, Grafton, Andover, Chester, Caven-
dish, Baltimore, Ludlow, Plymouth, Bridgewater, Thetford, Bethel,
Rochester, Warren, Braintree, Waitsfield, Moretown, Duxbury,
Waterbury, Bolton, Stow, Cambridge, Waterville, Berkshire, Eden,
Ixiwell, Belvidere, Johnson, Enosburg, WestfieU, Richford, Troy,
and Jay. Of these those of Grafton and Athens are stated to have
been longest worked and to have produced the most stone. The
beds lie in gneiss. Another important bed occurs in the town of
Weatherfield. This, like that of Grafton, b situated in gneiss, and
the material can be had in ine.<diaustible quantities. It was first worked
' G«okigy of Vermom, 1861, Vols. I and II.
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about 1847. The Rochester beds were at one time of great importance,
the stone being peculiarly fine grained and compact. It was once
much used in the manufacture of refrigerators. The bed at New
Fane occurs in connection with serpentine, and is some half mile in
length by not less than 12 rods in width at its northern extremity.
In Massachusetts quarries of soapstone have been worked from
time to time m Lynnfield and North Dana. The Lynnfidd stone
occurs associated with serpentine. It has not been quarried of late,
but was formerly used for stove backs, sills, and steps. In New
York State soapstone and talc occur in abundance near Fowler and
Edwards in St Lawrence County. Some of this is very pure,
nearly snow-white talc, and is quarried and pulverized for com-
mercial purposes, as already noted.
In Pennsylvania, in the southern edge of Montgomery County,
extending from the northern brow of Chestnut Hill between the
two turnpikes acrosss the Wissahickon Creek and the Schuylkill to
a point about a mOe west of Marion Square, there occurs a long,
straight outcrop of steatite and serpentine. The eastern and central
part of this bdt on the southern side consists chiefly of steatite, while
the northern side contains much serpentine, interspersed through
it in lumps. Only in a few neighborhoods, as at LaFayette, does
either the steatitie or serpentine occur in a state of sufficient purity
to be profitably quaried. (Plate XIX.) On the east bank of the
Schuylkill, about 2 miles below Spring Mill, a good quality of mate-
rial occurs that has long been successfully worked. The material
is now used principally for stoves, fireplaces, and furnaces, though
toward the end of the eighteenth century and during the early part
of the nineteenth, before the introduction of the Montgomery County
marble, it was in considerable demand for doorsteps and sills. It
proved poorly adapted for this purpose, owing to the unequal hard-
ness of the different constituents, the soapstone wearing away
rapidly, while the serpentine was left projecting like knots, or "hob-
nails in a plank."
Several small deposits of soapstone occur in Maryland, and
some of them have been worked on a small scale. The material is
of good quality, but apparently to be had only in small pieces.
In Virginia soapstone occurs in Fairfax, Fluvanna, and Bucking-
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914 THE NON-METALUC MlNER/ttS.
ham counties. There is also a bed at Alberene, Albemarle Comity,
a little west of Green Mountain. This is the bed so extensively
worked by the Alberene Soapstone Company. From these points
the bedfl extend in a southwesterly direction through Nelson Comity,
where tiiey are associated with serpentine; thence across the James
River above Lynchburg, and present an outcrop about 2 miles west
of the town on the road leading to Liberty; also one some 2^ miles
west of New London. Continuing in the same direction the bed
is seen at the meadows of Goose Creek, where it has been quarried
to some extent. Parallel ranges or soapstone appear near the
P^ River in Franklin County. About 30 miles southwest from
Richmond, at Chula, in Amelia County, there are outcrops
of soapstone said to be of fine quality, and in former times quite
extensively operated by the Indians. They have been reopened
within a few years and the material is now on the market.
North Carolina contains, in addition to an abundance of the finest
grades of talc and steatite as already noted, beds of the compact
common soapstone. Deposits in Cherokee and Moore counties
furnish especially desirable material for lubricating and other pur-
poses. Murphy, Guilford, Ashe, and Alamance counties are also
capable of affording good materiak, but much of it is inaccessible
at present on account of-poor railroad facilities.
Beds of soapstone are stated to occur in Saline County, Arkansas,
and in Chester, Spartanburg, Union, Pickens, Oconee, Anderson,
Abbeville, Kershaw, Fairfield, and Richmond counties in South Caro-
lina. Llano County, Texas, and Santa Catalina Island, California,
also contain good material of this nature.
Uses. — The uses to which talc and soapstone are put vary
greatly according to purity and physical characteristics. The white,
fibrous talc, from St. Lawrence County, New York, is used as a
filler in paper manufacture, something like 30 per cent of the weight
of printing paper being made up of this material. Pulverized talc
is also used as a lubricator, for which purpose it is remarkably
well adapted. Rubbed between the thumb and finger the powder
is smooth and oily, without a particle of grit. It is also used in
soap making, for which purpose it can, however, be considered
only as an adulterant, increasing the weight but not the cleaning
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J, Google
J, Google
properties of the article. It is further used as a dressing for fine
leathers, and in considerable quantities in foundry work. Small
quantities are used by shoe and glove dealers, and large quantities
in the form of "talcum powder" for toilet purposes. The pure
creamy-white talc, such as is obtained from North Carolina, is
used for crayons and slate pencils, while the still finer, crypto<rystal-
iine varieties are used by tailors under the name of French chalk
and for making the tips for gas burners. Fine compact grades of
a somewhat similar rock (agalmatolite) are used extensively in
China and Japan for small ornaments. The stone is readily carved
in fine sharp lines, and is a general favorite for making the grotesque
images for which these countries are noted, and which are often sold
throuji^out the country under the name of jadestone.
The following account of the soapstone industry of China is tak^i
from the Engineering and Mining Journal of September 30, 1893.
The material referred to as soapstone is, however, very probably
agalmatolite,
"The mines are distant 42 miles from Wenchow, and are reached
by a boat journey of 35 miles up the river, followed by a land journey
of 7 miles over rough ground. The hills containing steatite are
owned by 20 to 30 families, who in some cases work the mines them-
selves, in others engage miners to do it on their account. The
galleries are driven into the sides of the hills, and are often nearly
a mile in length. The stone when first extracted is soft, hardening
on exposure to the air. It is brought out of the mine in shovels,
and is sold at the pit mouth to the carvers at a uniform price of about
one-half a poiny per pound. This when the purchaser buys it in
gross. When picked over the mineral varies very considerably in
value — according to the color, size of the lump, or its shape. The
colors are given as purple, red, mottled red, black, dark blue, light
blue, gray, white, eggshell-white, 'jade,' beeswax, and 'frozen.'
Of these 'jade' (the white variety, not the green) and 'frozen' are
the most valuable. The industry finds employment for some 2,000
miners and carvers. A great impetus was given to it by the opening
of Wenchow to foreign trade. Previous to that event the chief
purchasers were officials and literary men, and the article most often
carved was a stamp or seal. When it was discovered that foreigners
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ai6 THE NON-MET^LUC MINERALS.
admired the stone, articles were produced to meet what was supposed
to be their taste. Such were landscapes in low or high relief, flower
vases, plates, card trays, fruit dishes, cups, teapots, and pagodas.
If left to his own devices the native carver proceeds first to examine
his stone, much as a cameo cutter would do, to discover how best
he can take advantage of its shape and shades of color." (See
further undo: Agalmatolite.)
The soapstones are suited for a considerable range of appli-
cation. Although so soft, they are among the most indestructible
and lasting of rocks, but are too slippery and perhaps of too somber
a color for general structural purposes. At present the chief use of
the material in the United States is in the form of thin slabs for sinks,
stationary washtubs, laboratory fittings, and electric switchboards.
At one time it was quite extensively used throughout New England
in the manufacture of stoves for heating purposes and to some extent
for fire-brick, the well-seasoned stone being thoroughly fireproof.
Ilie putting upon the market of imseasoned materials or of material
with bad veins, which caused the stone to crack or perhaps fly to
fragments when subjected to high temperature, aroused a prejudice
against the employment of this material, and the manufacture is
stated to have been to a considerable extent discontinued as a con-
sequence. In the manufacture of either stoves or washtubs, slabs
of considerable size, free from segregation nodules of quartz, pyrite,
or other minerals, or fram dry seams, are essential. As but few of
Ae now known outcrops can furnish material of this nature, the main
part of the business of the country is in the hands of but two or
three companies. The waste material from the quarries, or the
entire output in certain cases, is pulverized and used as a lubricant
or white earth, as is the micaceous variety.
13. PySOPHYLUTE; AGAIUATOLITE; AND FINITE (iN PART).
This is a hydrous silicate of aluminum corresponding to
the formula H^O, ALjOg, 48103. The analyses given below
show the average compositioo of the material as it occurs
in nature:
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Loc«lity.
KKmi.
Ahunina.
W.t«^.
Remwki.
65-93
I7-9S
»9-S4
7.08
5-40
V of iron, mignesia,
) and lime.
Deep River, North Carolina..
The mineral is not known in distinct crystak, but occurs rather
in foliated lamellar, massive and compact forms, closely resembling
some forms of talc, for which its soapy or greasy feeling renders it
very likely to be mistaken, though its hardness (a to 3.5) is somewhat
greater. The prevailing colors are white or greenish gray and dull
red, variously mottled.
Occurrence. — ^The principal localities furnishing pyrophyllite in
any considerable quantities in the United States are in the eittreme
north-central portion of Moore County and the south-central por-
tion of Chatham County, Nortli Carolina. The deposits are asso-
ciated with slates, but usually separated from them by bands of
siliceous and iron breccia from 100 to 150 feet in thickness. The
formation has a strike of approximately 55°-6o° E. and dips 60°-
70°-!- NW., and has been traced for a distance of upward of 6 miles.
Some of the bands are highly siliceous and of poor quality. Others
are entirely free from grit. Small seams of quartz often penetrate
the bed, and occasional particles of chlorite and hematite occur,
giving the material a speckled appearance. Of the 500 feet max-
imum thickness of the bed not over 100 feet are workable, and of
this not more than 25 per cent can be expected to prove merchant-
able.'
Uses. — The more compact varieties, like that of Deep River,
are used for making slate pwncils and tailors' chalk, or French
chalk, so-called. The still more compact forms, known as agal-
matolile and pagodite, are used extensively by the Chinese and
Japanese for making small images and art objects of various kinds.
Dana states, however, that a part of the so-called Chinese agal-
matolite is in reality pinite and a part steatite. The objects sold
by Chinese dealers at the various expositions of late years under
the name of jadestone are, however, of agalmatolite.
■ J. H. Pnn, Economic Paper No. 3, Nonh Caroliiw Ceologicsl Sune; , 1900.
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9l8
THE NON'METALUC MINERALS.
Finite: Agalmatolite in part. Composition, a hydrous silicate
of aluminum and the alkalies. According to Dana,' the name is
made to include a large number of alteration products of white
spodumene, nepheline, feldspar, etc. Professor Heddle has de-
scribed ^ a pinite (agalmatolite) occurring in large lumps of a sea-
green color, surroundir^ crystalline masses of feldspar in the granites
of Scotland, and which he regards as alteration products of oligo-
clase. The composition as given is : Silica, 48,72 per cent; alumina,
3T,56 per cent; ferric oxide, 2,43 per cent; magnesia, 1.81 per
cent; potash, 9.48 per cent; soda, 0.31 per cent; water, 5.75 per
cent.
r4. sepiolite; meerschauu.
This mineral is a hydrous silicate of magnesia, having the com-
position indicated by the formula H,Mg^i,Oi„= silica, 60.S per
cent; magnesia, 27,1 per cent; water, 12,1 per cent. The prevail-
ing colors are white or graybh, sometimes with a faint yeUowish,
reddish, or bluish-green tinge. It is sufficiently soft to be impressed
by the nail, opaque, with a compact structure, smooth feel, and
somewhat day-like aspect; rarely it shows a fibrous structure. In
nature it rarely occurs in a state of absolute purity. The first three
of the following analyses are quoted from Dana's Minerak>gy:
LoMlily
SiC
MgO,
FeO, I Hrt).
CO,.
Turkev
6... 7
61.30
53-97
S7-IO
=8.43
38-39
13.50
17. >6
0.06
0.08
/CuO
10.87
Trace
9.83
9.74
H.78
0.67
0.56
JHygroscopfcH,0
The name is from the German words Meer, sea, and Sckaum,
foam, in allusion to its appearance. The chief commercial localities
are in Asia Minor, Bosnia, and New Mexico.
' System of Mineralogy, 61b ed., p. 631.
' Mineralogical Magazine, IV, p. 315,
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SIUCATES. ai9
Mode of occurrence and origin. — According to J, Lawrence
Smith,* the Asiatic material occurs in the form of nodular masses
in alluvial deposits on the plain of Eski-Shehr. It was thought by
him to owe its or^in to the carbonate of magnesia derived from the
adjacent mountains, decomposed after its separation by waters
containing silica. This supposition he based in part upon the
presence of the carbonate in variable amounts in the sepiolite nodules,
and in part upon their association, even in the same mass, with
serpentine. In the light of to-day it would seem more probable that
the serpentine was itself a product of alteration of an igneous mag-
nesian rock (peridotite) and the sepiolite and magnesite (MgCOg)
incidental products, or perhaps products of a further alteration of the
serpentine in its turn. F. Katzer describes^ the Bosnian material
as likewise occurring in form of lumps and masses irregularly dis-
tributed throughout a Tertiary conglomerate, and also in lumps,
veins and aggregates in serpentine, the last named rock being de-
rived from a bronzite peridotite. He conceives the alteration (ser-
pentinization) to have been brought about through the agency of
water-carrying carbonic acid, a part of the magnesia separating out
as a carbonate, while a smaller portion combined with silica and
water to form the sepiolite.
In an article in the Cyclopedia of Arts and Sciences it is stated
that the meerschaum of the Crimea forms a stratum some 2 feet
thick beneath a much thicker stratum of marl. Cleveland in his
elementary treatise on minerals (1822) states that at Anatolia, in
Asia Minor, meerschaum occurs in the form of a vein more than
6 feet wide (?), in compact limestone. -At VaUecas, Spain, a very
impure form is stated to occur in the form of beds and in such
abundance as to be utilized for building material. Aside from the
localities above mentioned, sepiolite is known to occur in Greece,
at Hrubschitz in Moravia, and in Morocco, in all cases being asso-
ciated with serpentine, with which it is apparently genetically
related.
' Araeikan Journal of Science, 1S49, VIII, p. »S$.
' Berg- u. UUtteom&im. Jahrb., LVII, p. 65, Abstr. in Cbem. Abstr., Ill, October
=. '909. P- '^1-
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320 THE NON-METALUC MINERALS.
According to Kunz,' meerschaum has occasionally been met with
in compact masses of smooth, earthy texture in the serpentine
quarries of West Nottingham Township, Chester County, Pennsyl-
vania, Only a few pieces were found, but they were of good quality.
It also occurs in grayish and yellowish masses in the serpentine in
Concord, Delaware County, Pennsylvania. Masses of pure white
material, weeing a pound each, have been found in Middletown,
in the same county, and of equally good quality at the Cheever
Iron Mine, Richmond, Massachusetts, in pieces over an inch across,
also in serpentine at New Rochelle, Westchester County, New
York. Two localities for meerschaum have of late years been
exploited in the upper Gila valley of New Mexico, one some 23
miles northeast of Silver City, on Alunogen Creek and the
other about 12 miles northwest of the same city, in the caiion
of Bear Creek. The rock forming the walls of this cafion, and in
which the meerschaum occurs, is a gray cherty limestone of sup-
posed Ordovician Age, with intercalated strata of sandstone. The
meerschaum is reported " as occurring in veins, lenses, seams, and
balls, all but the last named filling fractures and joints in the lime-
stone. Chert is a common gangue mineral, and with it occur quartz,
calcite and clay. Two types or varieties of material are found:
One in the form of irregular nodules of all sizes up to several inches
in diameter, having an uneven fracture, and somewhat fibrous,
leathery, porous structure, and the other in a more massive form
and compact nature. The origin of the material seems to not have
been worked out, nor has the commercial value of the deposit yet
been fully demonstrated. The analysis given on p. 218 is of a
sample from the Dorsey claim on Bear Creek.
Uses. — The mineral owes its chief value to its adaptability for
smokers' use, being utilized in the manufacture of what are known
as meerschaum pipes. In Algeria a soft variety is used in place
of soap at the Moorish baths and for washing linen.
According to a writer in the Engineering and Mining Journal,'
the Eski-Shehr mineral is mined from pits and horizontal galleries in
' Gem* and Precious Stones, p. 189.
'D. B. Sterrett, Bulletin No, 340, U. S, Geologkal Survey.
' Volume LIX, 1895, p. 464.
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U-.
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much the same manner as coal. As first brought to the surface
it is white, with a yellowish tint, and is covered with red clayey
soil. In this condition it is sold to dealers on the spot. Before
exporting the material is cleaned, dried, and assorted, the drying
taking place in the open air, without artiiicial heat in summer, and
requiring from five to six days. The bulk of the material is sent
direct to Vienna and Paris.
15. CLAYS.
The term clay as commonly used is made to comprise materials of
widely diverse origin and mineral and chemical composition, but
which have in common the property of plasticity when wet, and
that of becoming indurated when dried either by natural or artificial
means. Of so variable a nature is the material thus classed that
no brief definition can be given that is at all satisfactory. , One
may perhaps describe the clays, as a whole, as heterogeneous ag-
gregates of hydrous and anhydrous aluminous silicates, free silica,
and ever-varying quantities of free iron oxides and calcium and
magnesian carbonates, all in a finely comminuted condition.
Origin and mode of occurrence. — The clays are invariably of
secondary origin — that is, they result from the decomposition of
pre-existing rocks and minerals and the accumulation of their less
soluble residues, either in place (residual clays) or through the
transporting power of ice and water (drift clays). That silicate
of aluminum is so characteristic a constituent of nearly all clays
is due to the fact that this substance is one of the most insoluble
of natural compounds, and hence when, under the action of atmos-
pheric or subterranean agencies, rocks decompose and their more
soluble constituents — as lime, magnesia, potash, soda, or even
silica — axe removed, the aluminous silicate remains.
The kaolins, which may be regarded as the simplest of clays,
are the product, mainly at least, of the decomposition of fcldsp>ars,
a form of decomposition which consists essentially of hydration
and a more or less complete removal of the lime and alkalies and
a part of the silica. The following tables show the composition
of the common feldspars and the approximate loss and gain of
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223 THE NON-METALUC MINERALS.
material they undergo in passing into the condition of kaolin. The
formula SijO^IjH^ given is, it should be noted, that of the mineral
kaolinite, of which the material kaolin is commonly regarded as an
impure form.
SiO, Al-O, Yi-O H,0 %
I. Orthodase 64.86 18.29 16.85 100.00
Lost 43-34 '6-85
Taken up . .
Kaolinite 31.61 18.19 ^ ^-45
SiO, A1,0, Na,0 H,0
Alhite 68.81 19.40 1 1.79
Lost 45'87 1 1.79
Taken up 6.85
Anorthite. .
Lost
Talfen up .
6.85
H,0
Kfu>linite 43'3o 3^-63 la.gi 93.8$
From this it appears that, in the case of orthodase and albite,
two-thirds of the silica and all the alkalies are removed. In all,
over half of the feldspathic constituents are lost during the transi-
tion, while, in the anorthite, only the lime is carried away. The
proportional loss and gain is shown as follows:
Onhoelsae.. iSi,0,AlK-4SiO,-K,0 + iH,0-Si,O^I^..
Albile 2Si,OrMNa-4SiOj-Na,0 + 2H,0 = SijO,Al^^
Anorthite. . . Si,0,A],Ca - CaO + 3H,0- Si,O^I,H,.
In Other words, two molecules of albite or orthoclase are neces-
sary for the formation of one molecule of kaolin, while, in the case of
anorthite, one molecule is sufficient to produce one molecule of
kaolin.
As to the method by which this decomposition is brought about
authorities differ. It has been commonly assumed that the same
was a purely superficial phenomenon, a form of weathering. Tlie
observed frequent asociation of kaolin with fluorine minerals led
von Buch and Daubr^e to suggest that in certain instances the
haolinization, as this form of decomposition is called, might be
due to exhalations of fluorhydric acid. J. H, Collins showed by
experiment the possibility of such an origin, and was led to think,
ovGoO'^lc
SILICATES, aaj
}n the case of veins and bands sometimes extending far below the
drainage level, no other conclusion was tenable.' Dr. Heinrich
Ries, in a paper read before the American Ceramic Society in 1900,
gave it as his opinion that the kaolins of Cornwall (England) and
possibly those of Zeltlitz in Bohemia were of deep-seated origin and
due to fluoric exhalations, as noted above. Recently H. RSsler
has come forward with an apparently exhaustive paper in which he
advocates this origin for all kaolins.* Inasmuch, however, as many
American kaolins do not occur in veins, but so far as observed are
merely superficial phases of granitic decomposition, so far-reaching
a conclusion cannot at present be accepted unqualifiedly. The
fact that a large portion of American kaolin deposits occur, so far
as known, in regions south of the glacial limit seems to substantiate
the prevailing opinion that such are due to long-continued — secu- .
lar — decay of rock masses through the action of heat and cold, mois-
ture and the carbonic acid of rainfalls, in short are due to weathering
processes, as arc many of the common days. It has been repeatedly
shown that rocks of any tyi>e containing aluminous sHicates will on
prolonged decomposition through atmospheric influences break down
into clayey soils and clays, the nature of which is dependent to a
considerable extent upon the character of the parent rock. Such
are the residual clays of non-glaciated regions, and of limestone
caves, and perhaps also the so-called Indianaite of Lawrence County,
Indiana.3
The assorting and transporting power of running waters rarely
allows beds of kaolin or other residual clays to remain in a
condition of virgin purity or even in the place of their origin. The
minute size and the shape of the constituent particles are such as
to render them easy of transportation by rains and running streams
to be redeposited in regularly stratified and laminated beds when
the streams lose their carrying power by flowing into lakes and
seas. It is through such agencies that have been formed the bedded
Leda and Champlain clays of the glacial period, the Cretaceous
' MineraloRical Magazine, VII, 1S86-87, p. 217.
' Neuea Jahrb. fUr Min. Geol. u. Pal. XV Beilage-Band, 1. Heft, 190a.
' See Rocks, Rock weathering, and Soils, id ed., pp. 150-373.
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224 7'H£ NON-METALLIC MINERALS.
clays of New Jersey and the fire clays of the Coal Measures, though
their original constituents may have been of purely chemical or
of mechanical origin.
The glacial clays of Wisconsin have been described by Cham-
berlain as owing their origin mainly to the mechanical grinding
of glacial ice upon strata of limestone, sandstone, and shale, resulting
in a comminuted product that now contains from 25 to 50 per cent
of carbonates of lime and magnesia. This product of glacial grind-
ing was separated from the mixed stony clays produced by the same
action by water either immediately upon its formation or in the
lacustrine epoch closely following. The process of separation
must have been rapid and comparatively free from the agency of
carbonated waters, otherwise the lime and magnesia would have
been leached out.
The formation of beds of clay has been confined to no par-
ticular period of the earth's history, but has evidently gone on ever
since the first rocks were formed and when rock decomposition began.
The older beds are as a rule greaily indurated and otherwise altered,
and in many instances no longer recognizable as days at aJL
Throughout the Appalachian region clay beds of Cambrian and
Silurian ^es have, by the squeezing and shearing incident to the
elevation of this mountain system, become converted into argillites
and roofing slates.
Mineral and chemical composUion. — Formed thus in a variety
of ways, and consisting frequently of materials brought from diverse
sources, it is easy to comprehend that the substances ordinarily
grouped under the name of clay may vary widely in both mineral
and chemical composition. It may be said at the outset that the
statement so frequently made to the effect that kaolinite or even
kaolin is the basis of all clays is not well substantiated.
Kaolinite is in itself not properly a clay, nor is it plastic. Further,
in many cases it is present only in non-essential quantities. More
open to criticism yet, because more concise, is the statement some-
times made that clay is a hydrated silicate of alumina having the
formula Al3C)3,2Si02 + 2H20. It is doubtful if, with the exception
of kLolin and halloysite, a day exists which could be reduced to
such a formula excepting by a liberal exercise of the imagination.
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SIUCATES. 22$
There is scarcely one of the silicate minerals that wQl not when
sufficioitly finely comminuted yield a substance possessing those
peculiar physical properties of unctuous feel, plasticity, color, and
odor which are the only constant characteristics of the multi-
tudinous and heterogeneous compounds known as clays.' Dau-
br^e, as long ago as 1878,^ pointed out the fact that by the
mechanical trituration of feldspars in a revolving cylinder with
water, an impalpable mud was obtained, which remained many
days in suspension, and on drying formed masses so hard as to
be broken only with a hammer, resembling the argillites of the
Coal Measures.
The kaolins, when examined under the microscope, are found
to consist largely of extremely minute colorless shreds of material
"which may be kaolinite; intermixed with this are fragments of
undecomposed feldspars and particles of quartz and other refrac-
tory minerals as tourmaline, iron ores, mica, etc., that were con-
stituents of the parent rock and have escaped decomposition. The
ordinary residual clays have a yet more indefinite composition, as a
rule are more or less ferruginous and contain sand particles, grains
of magnetite, titanic iron, garnet, rutile or any of the less destructible
minerals. The drift or transported clays are like heterogeneous
aj^egates. Prof. W. O. Crosby has shown that the ordinary glacial
Champlain or Leda clays of Cambridge, Massachusetts, contain
but from one-fourth to one-third their bulk of what he designates
"true clay," the remainder being finely comminuted material of
various kinds which he calls rock flour. The brick clays at Lewis-
ton and vicinity contain, as shown by the microscope, a compara-
tively small amount of material that can be designated kaolin, but
carry particles of free quartz, scales of mica, bits of still undecom-
posed feldspar and other silicate minerals, and more rarely tourma-
line, etc. Many of these clays are h^jhly calcareous, also — indeed
'ReffTTUig to the odor of day when a shower of rain firsX begins to wel a dry,
dayey soil, Mr. C. Tomlinson has remarked that it is commonly attributed to alumina,
and yet pure alumina gives oft no odor when hroathed upon or wetted. The fact is,
tbe peculiar odor refErred to belongs only to impure days, and chiefly to tboee that
contain oxide of iron. (Proceedings of the Geological Aasodatloai I, p. 343; qmted
in Woodward's Geology of Et^land and Wales, p. 439.)
*Geo)ogie Elpftimentale, 1S79, p. 351.
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aaO THE NON-METALUC MINERALS.
both lime and magnesia, in the form of carbonate, are common con-
stituents of any but the residual clays. The alkalies potash and'
soda are also common constituents, though occurring as silicates
in the undecomposed residual material. Iron in some of its forms,
as hydrated oxide, carbonate or sulphide, is an almost universal
constituent of clays of all kinds.
The above remarks will explain why a purely chemical analysis
of a clay may be of litde value for the purpose of ascertaining its
suitability for any particular purpose. It is essential that we know
not merely the presence or absence of certain elements, but also
how these elements are combined. Further than this, except in
brick and tile making, few clays are used in their natural condition,
being first purified by washing or mixed with other constituents to
give them body or fire-resisting properties.
Kinds and classiJUation. — From a geological standpoint the
clays may be divided into two general classes, as above noted, (i)
residual, and (z) transported, the first class including a majority of
the kaolin, halloysite, etc., and the second the ordinary brick and
potters' clays, the loess, adobe, Leda, and the bedded alluvial deposits
of the Cretaceous, Carboniferous, and other geological periods.
Special names, based upon such properties as render them peculiarly
adapted to economic purposes, are common. We thus have (i)
the kaolin and China clay, (2) potters' clay, {3) pipe clay, {4) fire
clay, (s) brick tile, and terra cotta clays, etc., (6) slip clays, (7)
adobe, and (8) fullers' earth. These will be discussed in the order
given, though they must necessarily be discussed but briefly, since
the subject of clays alone could be made to far exceed the entire
limits of the present volume. The names fat and lean clays are
workmen's terms for clays relatively pure and plastic or carrying
a large amount of mechanical admixtures, such as quartz sand.
The term ganister is sometimes applied to a siliceous fire-clay or a
mixture of fire-clay and sand used for refractory purposes in steel
and iron works,'
' The name is somewhat loosely applied, and incapable of exact definition. Page,
in his dictionary of lemis, defines il as "The local name for a fine hard-grained grit
which occurs under certain coal beds in Derbyshire, Vorluhire, and the north of
England."
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SILICATES. aa?
(i) China clays. — Under the name of kaolin, or China clay, it is
customary to include a white pulvenJent highly plastic material,
resulting from feldspathic decomposition, and used in the manu-
facture of the finer grades of porcelain and china ware. The name
kaolin, as applied, is due to a. misconception, the material being
supposed to be similar to that obtamed by the Chinese at Kaoling
(Highrklge), and from which was made the high grades of Chinese
porcelain.
According to Richthofen,' however, the material from which
the porcelain of Kjng-te-chin is made is not kaohn at all, as the
word is now used, but a hard greenish rock which occurs intercalated
between beds of clay slate. He says:
" This rock is reduced, by stamping, to a white powder, of which
the finest portion is ingeniously and repeatedly separated. This is
then molded into small bricks. The Chinese distinguish chiefly
two kinds of this mineral. Either of them is sold in King-tc-chin
in the shape of bricks, and as either is a white earth, they oSer no
visible differences. They are made at different places, in the
manner described, by pounding hard rock, but the aspect of the
rock is nearly alike in both cases. For one of these two kinds of
material, the place Kaoling ('high ridge') was in ancient times in
high repute; and though it has lost its prestige since centuries, the
Chinese stiU designate by the name ' Kao-ling ' the kind of earth
which was formerly derived from there, but is now prepared in other
places. The application of the name by Berzelius to porcelain
earth was made on the erroneous supposition that the white earth
which he received from a member of one of the embassies occurred
naturally in this state. The second kind of material bears the name
Pe-tun-tse ('white clay'),"
The following analysis will serve to show the average compo-
sition of (i) the natural material from King-te-Chin, such as is
used in the manufacture of the finest porcelain; (II) that from the
same locality used in the so-called blue Canton ware; (III) that of
the English Cornish or Cornwall stone; (IV) washed kaolin from
'American Journal of Science, 1871, p. 180.
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aa8 THE NON-METALUC MINERALS.
St. Yrieux, France, and (V) washed kaolin from Hockessin, Dela-
ware.'
CoaMitaentt.
I.
II.
111.
IV.
V.
73-SS
ai.09
\l$
■=7
1.17
48.68
36.9J
13.13
48.73
37-o»
■79
.16
\'i
17 A3
■"5
.46
i.»6
MuDc^a.
Po^. . . .
Combined »at«r....
Total
1.61
W.62
99-70
99-9*
9983
ii».09
Plate XXI, Figs, i and 3, will serve to show the shape and
fcind of the particles in the mineral kaolinite and in a prepared sample
of the Hockessin kaolin, as seen under the microscope.
The name halloysite is given to a white or yellowish material
closely simulating kaolin in composition, but occurring in indurated
masses, with a greasy feci and luster, and which adheres strongly to
the tongue, a property due to its capacity for absorbing moisture.*
As it is utilized for much the same purpose as is kaolin, it is included
here.
Halloysite is described by Gibson" as occurring in a bed some
3 feet in thickness, lying near the base of the Lower Siliceous (L,
Carboniferous) formation, a little above or close to the Black Shale
(Devonian), in Murphrees Valley, Alabama. This bed has been
worked with satisfactory results near Valley Head, in Dekalb
County. The present writer has found the material in compara*
tively small quantities, associated with kaohn, in narrow veins ia
the decomposing gneissic rock near Stone Mountain, Georgia. A
■ Analyses 1 end II by J. E. Whitfield, Bulletin 17, U. 5. Gralofpcal Survey; III
from Langenbect'i Chembtiy of Pottery; IV from Zirkel's Lehrbuch der Pctro-
graphie. III, p. 758, and V by George Sleiger, U. S. Geological Survey.
' This proprrty b characteristic of nearly all clay compounds when they aie dry.
It is lo this same property that many of (he so-called "mBds(oncs"owe thrir Imagi-
nary virtues. Nearly all the stones of this type emmined by the writer have proved
to be of indurated clay, halloysite, or a closely related compound. When applied
to a fresh wound, such adhere until they become satumted with moisture, when they
fall away. Their curative powers are of course wholly imaginary.
' Geok^iatl Survey of Alabama. Report on Muiphreei Valley, 1B93, p. in.
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PLATE XXI.
Fig. I, Kaolinite, and Fic, i, Washed Kaolin as Seen under ihe Microscope.
[U. S. Nalional Museum.] ,
[Faciitg page 128.]^ ^)ij ' ^'
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sjmikr occurrence is described near Elgin, Scotland. Near TUffer,
Styria, halloysite is described ' as occurring in extensive thick and
veinlike agglomerations in porphyry. It is quite pure, and in the
form of irregular nodules of various sizes, frequently with a pellucid,
steatite-like central nucleus, passing outwardly into a pure white
substance, greasy to the touch, in which are occasionally included
minute pellucid granules. Outside it passes into an earthy, friable
substance. The following analyses show the varying composidoa
of halloysite from (I) E^in, Scotland, (II) Steinbruck, Styria, and
(III) Detroit Mine, Mono Lake, California:
Conttituent*.
I.
II.
IIL
HI
1. 4 J
0.2$
19-34
40.7
38.40
D.60
1.50
It
Water . . .
18.00
iSjm
99..O
A white chalky halloysite from the pits of the Frio Kaolin Mining
Company in Edwards County, Texas, has the composition giverk
below as shown by analyses made in the laboratory of the depart-
ment of Geology in the National Museum :
Per Cat.
4S.8>
39-77
0.30
13.38
W.»7
The material is somewhat variable, corresponding in composition
to the halloysite described by Dana, and being, in part, non-plastic,
and in part plastic to an extraordinary degree. The plastic portions
are almost as gritless as starch paste. Its appearance under the
microscope is shown in Plate XXII, F^. i, the interspaces of the
' Mineralogical MagAiine, II, 1878, p. 264. ,
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330 THE NON-METALUC MINERALS.
visible angular particles being occupied by the pasty, almost amor-
phous material. The particles themselves act very faintly on polar-
ized light, and it is not possible to determine their miner^ogical
nature by optical means alone. Much of the material is evidently
of a colloidal nature.
The name Indianaite was given by Cox to a variety of halloy-
site found in Lawrence County, Indiana, and regarded by him as
resulting from the decomposition of Archimedes (Lower Carbonif-
erous) limestone. It is represented as forming a stratum from
6 to lo feet thick., underlying a massive bed of Coal Measure con-
glomerate TOO feet thick and overlying a bed of limonite 2 to 5 feet
thick. The material like kaolin is used in the manufacture of
porcelain ware. The composition as given by Dana is as follows:
Silica 39 f)er cent, alumina 36 per cent, water 23.50 per cent, lime
and magnesia 0.63 per cent, alkalies 0.54 per cent, total 99.67 per
cent.
(2) The potters' and (3) pipe clays belong mainly to what are
known geologically as bedded clays, and are as a rule very siliceous
compounds, carrying in some instances as much as 50 per cent of
free quartz and 6 to 10 per cent of iron oxides and other impurities.
They are highly plastic and of a white to blue, gray, or brown color
and bum gray, brown, or red. The tables on page 248 will show
the varying composition of materials thus classed.
(4) The fire clays, so called on account of their refractory nature,
differ mainly in the small percentages of lime and the alkalies
they carry, and to the absence of which they owe their refractory
properties.
The bedded clays include also most of the brick, tile, and terra
cotta clays. In the United States they reach their maximum de-
velopment in strata of Cretaceous and Carboniferous ages. To
the Cretaceous age bebng the celebrated plastic clays of New Jersey
and South Carolina and a very large proportion of the brick, tile,
and terra-cotta clays of Delajvare,' Maryland, and Virginia. The
New Jersey beds are very extensively utilized in Middlese.\ County
' This of course does not include ibe kaolin depoaiu of Hockessin, Nawcastle
County, and similar deposits.
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PLATE XXII.
Fio. I, Halloysile, and Fw. i, Glacial (Leila) Clay, as Si-en umlcr Ihe MirrMcopei ^
[U. S. Nalional Museum.] ^ ^ ^'^'^ ' ^
[I'atiftg page ajO.l
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SlUC/tTES. aji
and fully described in the State Geological Reports,* from which
the following section is taken :
Peat.
(i) Dark-colored clay (with beds and Inmiiue of Ignite) 50
(1) Sandy clay, with sand in alternate layers 40
{3) Stoneware clav bed 30
(4) Sand and sandy clay (with lignite near the bottom) 50
(s) South Amboy fire-clay bed 30
{61 Sandy clay (generally red or yellow) 3
(7) Sand and kaolin 10
(8) Feldspar bed S
(9) Micaceous sand bed 20
(10) Laminated clay and sand 30
(11) Pipe clay (top white) , 10
(tj) Sandy day (including lea£ bed) j
(13) Woodbridge firc<lay bed ao
(14) Fire-sand bed 15
Raritsn clay beds:
(is) Fireclay 15
(16) Sandy day 4
(17) Potters' clay ao
Totiil 347
The Aiken, or Savannah River region of South Carolina furnishes
a remarkable illustration of transported or bedded clays free from
admixture with foreign materials. These clays are nearly pure
kaolin, the materials of which were derived from decomposing
granites and brought by easterly flowing rivers of Cretaceous times
to be deposited in the quiet marginal waters of the then existing
seas. The beds as now uplifted are overlaid by sand and gravels
of the Lafayette and other subdivisions of the Pliocene period, and
are themselves interbedded with sands and gravels bearing witness
to the varying strength of the currents instrumental in their trans-
portation. The material is reportetl as yielding on analysis; SiOa
45.02 per cent; AI2O3 38.1)8 per cent; FeaOa 0.77 percent; FiOz
0.85 per cent; CaO 0.03 per cent; MgO 0,07 per cent; Na20 0.55
per cent; K3O 0.26 per cent; Ignition 13.58 per cent,^
* Report on Clay Deposits of Woodbridge, South Amboy, and other places in New
Jersey, 1878.
' A Prctiminary Report on Clays of South Carolina, by Earle Sloan, 1904.
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aja THE NON-METALUC MINERALS.
The following section from Bulletin No. 3 of the Geological
Survey of Missouri will serve to show the alternating character o(
the Coal Measure clays at St Louis and their varying qualities as
indicated by the uses to which they are put: *
"(i) Loess, 20 feet
"{2) Limestone (Coal Measure), 5 feet.
" (3) Clay, white and yellow, used for sewer-pipe manufacture,
called 'bastard fire clay,' 3 to 4 feet.
"(4) Clay, yellow and red, sold for paint manufacture and for
coloring plaster and mortar, called 'ochre,' 3 feet.
"{e) Clay, gray to white, used for paint manufacture and filling,
1 foot 6 indies.
" (6) Pipe clay, variegated, reddish brown and greenish, called
'keel,' 12 feet,
"(7) Sandstone.
"(8) Slaty shale.
"(9) Coal.
"(10) Fire clay, becoming sandy toward the base."
When first mined these Coal Measure clays are usually very
hard, but on exposure to the weather slake and fall into powder.
They are as a rule much less fusible than are the glacial clays, and
are used mainly in the manufacture of fire brick, sewer pipe, terra-
cotta stoneware, as crocks, fruit jars, jugs, etc., glass and gas retorts,
smelting pots, etc. Some of these articles are made direct from the
natural clays, while others are from a mixture of several clays or of a
clay mixed with pwwdered quartz and feldspar.
(5) For ordinary brick-making purposes a great variety of ma-
terials are employed; in some cases residuary deposits, and in others
alluvial and sedimentary. Throughout the glacial regions of the
United States a fine unctuous blue-gray material, laid down in estu-
aries during the Champlain epoch, the so-called Leda clays, are
the main materials used for this purpose. The bowlder clays of
the glacial regions are also sometimes used when sufficiently homo-
geneous.
■ BulletiD No. 3, Geokigiail Survey of Minoiui, 1890.
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SILICATES 333
The prevailing colors of the Leda clays are blue-gray below
the zone of oxidation and yellowish or brownish above. They all
carry varying amounts of iron, lime, magnesia, and the alkalies,
and when burned turn to red of varying tints. They fuse with
comparative ease and are used, aside from brick and tile making,
for the coarser forms of earthenware, as flower pots, being as a
rule mixed with siliceous sand to counteract shrinkage. The mining
of such material is of the simplest kind, and consists merely of
scraping away the overlying soil and sand, if such there be, and
removing the day in the form of sidehill cuts or open pits.
Plate XXIII, facing page 232, shows a cut in one of the beds at
Lewiston, Maine. The material here is fine and homogeneous,
of a blue-gray color, and contains no appreciable grit It is
mixed with siliceous sand and used for making bricks, baking
red. An analysis of the material in its air-dry state yielded
results as below:
P>rcBiug«.
09
?5
99.61
The appearance of the Lewiston clay under the microscope is
shown in Plate XXIII, Fig. 2.
Leda clays from Beaver County, Pennsylvania, used in the
manufacture of terra cotta at New Brighton, are reported * as having
the following composition :
' Second Geological Survey of Pennsylva
P- »57^
, Report of Chemic&l Aoalysei
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THE NON-METALLIC MINERALS.
CmudcuonW.
46.160 67.780
26.976 16.390
7.214 4.570
a!2io !6oo
1.530 .717
3.146 3-001
...330 6.340
99.386
99.088 1
Vitrified brick for street pavements are made from fusible clays,
sometimes in their natural condition and sometimes mixtures of
ground shale and clay.
The following analyses are given of the materials used by the
Onondaga Vitrified Pressed Brick Company, of New York;*
0^.,.^.
layer in
■hale bank
11,
eatslitbl"
Red shale.
Blue shale.
Clar-
35. +0
9.46
3.34
23.81
■9S
4.34
4-3°
'i\
S-oi
533°
18.85
6-SS
4-49
Trace.
4S-3S
13.19
■in
1.14
8.90
Water and organic matter
7.60
99*8i
99-5')
99.89
99-79
99-86
(6) The name slip clay is given to a readily fusible, impalpably
fine clay used for imparting a glaze to earthenware vessels. These
clays carry iron oxides, potash, and soda, together with lime and
magnesia, in such proportions that they vitrify readily, forming
thus an impervious glass over those portions of the ware to which
ihey are applied.
The following analyses show (I) the composition of a slip clay
used in pottery works in Akron, Ohio, and (II) one from Albany,
New York:
< fiulleliD of the New York State Museum, III, No. 13, March, 1895. Claj
Industries of New York, p. 300.
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ConalitucnH.
I. II.
60.40
11
4.18
0.87
0.6^
ox)9
8,0s
S8-S4
"5-4"
6.30
3-40
4-45
Carbonic acid and water
8.0S
,co.oc
100.47
The Albany clay is stated by Nason ' to glaze at comparatively
low temperatures and to rarely crack or check. It occurs in a
stratum 4 to 5 feet thick. It is used very extensively in the United
States, and has even been shipped to Germany and France.
(7) The name adobe is given to a calcareous clay of a. gray-brown
or yellowish color, very fine grained and porous, which is sufficiently
friable to crumble readily in the fingers, and yet has sufficient coher-
ency to stand for many years in the form of vertical escarpments,
without forming appreciable talus slopes. It is in common use
throughout Arizona, New Mexico, and Mexico proper for building
material, the dry adobe being first mixed with water, pressed in
rough rectangular wooden molds some 10 by 18 or more inches and
3 or 4 inches deep, and then dried in the sun. In some cases chopped
straw is mixed with it to increase its tenacity. Buildings formed
of this material endure for generations and even centuries in arid
climates. The material of the adobe is derived from the waste of
the surrounding mountain slopes, the disintegration being mainly
mechanical According to Prof. I. C. Russell it is assorted and
spread out over the valley bottoms by ephemeral streams. It con-
sists of a great variety of minerals, among which quartz is con-
spicuous. The chemical nature of the adobes varies widely, as
would naturally be expected, and as is shown in the following
analyses from Professor Russell's paper:^
' Forly-seventh Annual Report of the Slate Geologist of New York, 1893, p. 468.
' Subaerial Deposits of North America, Geological Magazine, VI, 1889, pp. 389
and 342-
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33*
THE NON-METMLUC MINERALS.
ANALYSES 01* ADOBE.
SiO .
AlA. ...
Fe-O,. ...
MnO
CaO
M^....
K-O
Na-O. ...
ca
I^::::
CI
H,0
Organic m
ToUl,
66.6Q
.6.67
4.1M
0.64
36.40
0.67
Tmce
0.77
35-84
Trace.
Tiace.
K)-S7
(8) The name loess is given to certain Quaternary surface de-
posits closely simulating adobe, but concerning the origin of which
there has been considerable dispute. Deposits in the United States
are, according to the best authorities, or subaqueous origin. Clays
of this nature are, as a rule, higher in silica than the adobes and
correspondingly poorer in alumina. Loess is a common surface
deposit throughout the Mississippi Valley, and is in many instances
of such consistency as to be utilized for brickmaking.
The analyses given on p. 237 are from Professor Russell's paper.
Properties of Clays. — The cause of the peculiar properties of
clays, particularly those of plasticity and induration, cannot as
yet be said to have been fully explained. Various explanations
have been made with reference to plasticity, but none which have
proven to be conclusive. It has been ascribed to the alumina,
to the combined water and the shape and size of the constituent
particles and to the presence of colloidal matter, but no one
quality seems to cover all cases, and in the end it will probably
be shown that there are many phases of plasticity due perhaps
to as many causes. Cook thought to show • that some of
die non-plastic clays which become plastic on kneading were
* Report on Clky Deposits^ Geological Survey of New Jeraej.
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P tmt LOEBS OF tHE MISSISSIPPI V
Conatitueote.
SiO,
ALO,
F?0..
TiO,
P,Or
MnO
c»o
MgO
N«,0
K-O
&?:;::::::::::
SO-
c.
Touil
a.6R
64.61
a. 03
,10.64
3-53
0^6
0.51
a. Coataiiu H of organic matter, dried at 100° C.
composed of masses of hexagonal plates or scales piled up in loi^
bundles, and that the kneading necessary to produce plasticity broke
up the bundles leaving a homc^neous matrix of crushed material
derived therefrom. Subsequent investigation has, however, failed
to confirm this view. The presence of combined water has un-
doubtedly some effect, since clays so highly heated as to drive off this
water are no longer plastic. The alumina alone cannot be the
cause, otherwise kaolin would be one of the most plastic of clays,
which is far from being the case. Moreover there are other hydrous
aluminum compounds which are not plastic in the least. Accord-
ing to certain Russian authorities plasticity is due not only to the
interlocking of clay particles but varies with the texture, the ex-
tremely coarse and fine varieties being less plastic than the inter-
mediate forms. This view has, in the past, been held by Dr. H.
Ries and H. A, Wheeler.^ H. Rosier ^ regards plasticity as due to
the flattened form of the constituents, their softness and their fine-
ness, and there is much to support this view.
■ Clajr DepoailB and Clay Industi7 in North Carolina, Bulletin No. ij, North
Cuolina Geological Survey, 1S97. See abu Clayi, Occurrences, Properties, and Vacs,
1906.
' Neues Jahib. lOr Min. u. Paleon., Beilage-Band, a. Heft, Vol. XV, 1901.
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338 THE NON-METALLiC MINERALS.
So far as the compiler's own observations go, plasticity is not
dependent wholly upon hydration nor size nor shape of the constit-
uent particles. The glacial (Leda) clays are made up of fresh,
sharply angular particles of various minerals and contain less than
5 per cent combined water; yet in their natural condition they are
extremely plastic, and scarcely less so when mixed with two-fifths
their bulk of ordinary siliceous sand, as is done in the process of
brickmaking. The Albany County, Wyoming, clay, on the other
hand, equally or even more plastic and exceedingly pasty, is made
up of extremely minute particles of fairly uniform size, scarcely
angular, and apparently all of the same mineral (colloidal) nature
throughout. This yields some 16 per cent of water, on ignition, as
shown in analysis, p. 247. On the whole, the evidence seems to
show that the plasticity is due to the manner in which the particles
conduct themselves toward moisture, and this is apparendy de-
pendent upon the size and shape and the proportional admixture
of varying sizes of the constituents rather than upon their chemical
composition. The colloidal nature of the constituents of certain
clays is undoubtedly an important factor.^
The expulsion of the absorbed and combined water in a clay is
nearly always accompanied by a diminution in volume, which varies
directly as the water, or the purity of the clay. Pure kaolin shrinks
as much as one-fourth of its bulk, it is stated, sometimes even
more. The sandy clays used in making sewer-pipe and stoneware
shrink in the tempered state from one-ninth to one-sixteenth, usually
about one-twelfth.
A clay, when all the water of crystallization is expelled, will not
shrink any more at red heat, but with increased heat will continue
to shrink up to the moment of fusion. A pure kaolin apparently
shrinks when heated a second time, even if the water is all expelled
by the first heat, yet it is practically impossible to fuse it. But a
good flint clay containing some sand will lose all shrinkage on being
once calcined at white heat. Such clay is then used to counteract
shrinkage in a body of green clay, as b also siliceous sand. Many
I See The Colloidal Matter of Clay and lis Measutemeni, Bulletin No. 388, U. S.
Geological Survey, 1909.
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SlUCATES. 939
clays contain sand enough naturally and some are so sandy as to
actually expand on heating, though usually at the expense of sound-
ness of structure; for the particles of clay will shrink away from
the grains of sand, rendering the product very friable.
The refractory or fire-proof property of clay depends largely
upon the alumina and silica, and their freedom from all constituents
which are fusible in themselves or which would combine with others
to form a flux. Pure alumina, or pure quartz alone, is practically
infusible. The constituents tending to make a clay fusible are
iron, soda, potash, lime, and magnesia. Which of these b the more
detrimental it would be difficult to say. Iron is not so powerful
a flux as either potash or soda; but on the other hand it is much
more abundant, and may moreover impart an unsatisfactory cobr.
The extent to which iron may be present without detriment
is a point on which authorities do not agree. The Stourbridge
clay of England has 2.35 per cent of iron, with extremes of 1.43 and
3.63 per cent. Gros Almerode clay has 2,12; Coblentz, 2.03; New
Castle, 2.32, and yet all these are famous fire clays. Test mixtures
of iron and pure kaolin have been run higher than this and have
stood well, but as a general rule it is unsafe to rely for Are qualities
on a clay with over 2 per cent of iron, particularly if the other im-
purities are developed in any amount. It is a well-known principle
in chemistry that mixtures of bases are much more active fluxes
than an equal amount of any one base; so with iron, its effect shows
worse when in presence of other fluxing agents.
The condition of the iron, whether as a sesquioxide or protoxide
is also an important matter, the latter form only, it is stated, being
likely to combine with the silica, to form silicates.
Sulphide of iron ha.s a bad effect, since its decomposition gives
rise to the lower oxide; the effect which the sulphur may have must
also receive consideration. Iron in the uncombined state imparts
to a piece of ware a buSor red color; when combination begins
and progresses the ware becomes of a bluish-gray cast, deepening
as the fusion of the iron proceeds, and finally becoming glassy black
if much iron is present.
In any but the glacial clays the comparatively small amounts
of lime and magnesia present causes them to be but little thought
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aAO THE NON-METALUC MINERALS,
of as detrimeatal. They occur both as silicates and carbonates.
When present as carbonates they combine at a higher temperature
tiian is required for iron or potash. The Milwaukee brick clays,
as already noted, carry. considerable amounts of carbonates of Ume
and magnesia, and require a very hot bum, but when once the lime
and silica combine they destroy the effect of 5 per cent of iron, and
impart a cream color. A brick of this kind presents an even, fine-
grained, vitrified appearance on its fracture.'
The amount of potash which a clay may contain and keep its fire
properties b variously put by different authorities. As with iron,
kaolin will stand a good deal when no other base is present, but a
multiplicity of bases makes fusion easy. Titanic acid in the form
of ilmenite or rutile, is regarded as neutral to fire qualities, being
itself practically infusible.
Testing clays. — Knowing the effect of the various constituents in
promoting fusion or imparting color changes it might at first thought
seem that chemical analyses would serve to indicate the uses to which
any clay was best adapted. In practice, however, it is not customary
to rely wholly on analyses, but rather to couple them with special
tests made to ascertain their strength and fire-resisting properties.
Fire tests are of two kinds — one consists in subjecting the clay
' They (lime and magnesia) have also ihc remarkahle property of uoiling with the
iroD ingredient to form a light-rolorcd alumina-lime-magnesia-iroD silicate, and thus
the product is cream-colored instead of red. Mr. Sweet has shown by analysis that
the Milwaukee light-colored hrick contain even more iron than the Madison red
brick. At numerous points in the Lake region and in the Foi Kiver valley cream-
colored brick are made tram red clays. In nearly or quite all cases, whatever the
origina] color o( the clay, the brick are reddish when partially burned. The explana-
tion seems to be that at a comparatively moderate temperature the iron constituent
is deprived of its water and fully oxidized, and is therefore red, while it is only at
a lelatively high heat that the union with the lime and magnesia takes place, giving
rise to the light color. The calcareous and magnesian clays are, therefore, a valuable
substitute for true aluminous days, for they not only bind the mass together more
firmly, but give a color which is very generally admired. They have also this practical
advantage, that the efiects of inadequate burning are made evident in the imperfect
development of the cream color, and hence a more carefully burned product is usualkf
secured. It is possible to make a light-colored brick from a clay which usually bums
red by adding lime. The amount of lime and magnesia in the MUwaukec brick is
about 35 per cent In the original clays in the form of carbonates they make up about
40 per cent. (Geology of Wisconun, 1, 1873-79, P- ^0
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to absolute heat without the action of any accompaniments, and
the other in putting the clay through the course of treatment for
which it is designed to be used. The former develops the absolute
quality of the clay as good or haiS, the latter proves or disproves
the fitness of the clay for any particular work. The latter is better
of course as a business test wherever it b practicable to use it. The
former can be made only in a specially adapted furnace. The clay
in this test is cut into one-inch cubes with square edges, and is set
in a covered crucible resting on a lupip of clay of its own kind, so
that it touches no foreign object The heat is then applied, and
its effect will vary from fusing the mass to a button to leaving it
with edges sharp and not even glazed on the surface. Experience
soon renders one proficient in judging of clays by this test.'
A method of testing the fusibility of clays by comparing them
with samples of known composition and fusibUity has of late years
come into extensive use. These prepared samples, known from
their inventor and their shape as Seger's pyramids, or cones, consist
of mixtures in varying proportions of kaolin and certain fiuxes, so
prepared that there is a constant difference between their fusing
points. When such cones, together with the samples to be tested,
are placed in a furnace or kiln, they begin to soften as tiie tem-
perature is raised, and as it approaches their fusion points 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 have
been reached.^
Uses. — Clay when moistened with water is plastic and suf-
ficiently firm to be fashioned into any form desired. ' It can be
shaped by the hands alone; by the hands applied to the clay as
it turns with the potter's wheel, or it can be shaped by molds,
presses, or tools. When shaped and dried, and then burned in
an oven or kiln, it becomes firm and solid, like stone; water will
not soften it, it has entirely lost its plastic property, and is per-
roanendy fixed in its new forms, and for its designed uses. These
'Geological Survey of Ohio, Economic Geology, V, pp. 651-655.
See Dr. Ries's paper on Norih Carolina clays, already quoted, and also his
numerous contributions on their subject in the volumes of the United States Geolog-
icai Surrey relating to mineral statistics.
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343 THE NON'METALUC MPJERMLS.
singular and interesting properties are possessed by clay alone,
and it b to these it owes its chief utility. It is used (i) for making
pottery; (2) for making refractory materials; (3) for making build-
ing materials; (4) for miscellaveous purposes.
Pottery. — Clay worked into shapes and burned constitutes
earthenware. The ware of itself is porous, and will allow water
and soluble substances to soak through it. To make it hold
liquids, the shaped day before burning is covered with some sub-
stance that in the burning of the ware will melt and form a glass
coating or glazing which will protect the ware, and give it a clean,
smooth surface. The color of the ware depends on the nature of the
clay. Clays containing oxide of iron bum red, the depth of color
depending on the amount of the oxide, even a small fraction of 1 per
cent being sufficient to give a buff color.
Clay containing oxide of iron in sufficient quantity to make it
partially fusible in the heat required to bum it is called stoneware
clay. The heat is carried far enough to fuse the particles together
so that the ware is solid and will not allow water to soak through
it; but not so far as to alter the shapes of the articles burned. The
oxide of iron by the fusion combines with the clay, and instead
of its characteristic red, gives to the ware a bluish or grayish
color.
Clay which is white in color and -entirely free from oxide of iron
may be intimately mixed with ground feldspar or other minerals
which contain potash enough to make them fusible, and the mixture
still be plastic so as to be worked into forms for ware. When burned,
such a composition retains its white color, while it undergoes fusion
sufficient to make a body that will not absorb water. Ware of this
kind is called porcelain or china.
Refractory materials. — Modern improvements in metallurgy,
and furnaces for many other industrial purposes, are dependrat
to a great degree on having materials for construction which will
withstand intense heat without fusing, cracking, or yielding in any
way. The two materials to which resort is had in alnMSt all cases are
pure aluminous clay, and quartz in the form of sand or rock. They
are both infusible in any but the verj- highest furnace heats. A clay,
however, is liable to have in it small quantities of fusible constituents
ovGoO'^lc
SlUCATES. 243
and to shrink whai heated to a high temperature. Quartz rocks
are liable to crack to pieces if heated too rapidly, and both the
rocks and sand are rapidly melted when in contact with alkaline
earths, or metallic oxides, at a high temperature. They do not,
however, shrink in heating. Bricks to resist intense heat are made
of clay, of sand, or of a mixture of clay and sand. The different
kinds are specially adapted to different uses.
To make fire bricks a clay which stands an intense heat is se-
lected. This is tempered so that it may not shrink too much or
unevenly in burning, by adding to the raw clay a portion of clay
which has been burned till it has ceased to shrink and then ground,
or a portion of coarse sand, or a quantity of feldspar. These ma-
terials are added in the proportions which the experience of the
manufacture has found best. The formula for the mixture is the
special property of each manufacturer, and is not made public. The
materials, being mixed together and properly wet, are- mokled in
the same way as common bricks, and after they have dried a little
they are put into a metallic mold and subjected to powerful pressure.
They are then taken out, dried, and burned in a kiln at an intense
beat.
It does not appear which is the best for tempering, burned and
ground clay, or coarse sand, or feldspar. Reputable manufacturers
are found who use each of these materials, and make brick that
stand fire well.
Fire bricks intended, in addition to their refractory qualities, to
retain their size and form under intense heat without shrinkage,
have been made to some extent The English Dinas bricks are
of this kind, and the German and French "silica bricks." The
Dinas bricks are of quartz sand or crushed rock, and contain very
litde alumma and about i per cent of lime. They stand fire re-
markably well, the lime causing the grains of sand to stick together
when the bricks are intensely heated. In the other "silka bricks,"
fire clay to the amount of 5 or 10 per cent is mixed with the '
sand, the plastic material causing the particles of sand to adhere
sufficiently to allow handling before burning.
Paper clay. — Clay which is pure white and that also which is
discolored and has been washed to bring it to a uniform shade of
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244 THE NON-MBTaLUC MINERALS
color, is used by the manufacturers of paper hangings, to give the
smooth satin surface to the finished paper. It is used by mixing it
up with a thin size, applying it to the surface of the paper, and
then polishing by means of brushes driven by machinery. The
finest and most uniformly colored clays only are applicable to this
use, and they are selected with great care. Clay is also used to
give body and weight to paper. Heavy wrapping paper, such as
is used by the United States Post-office Department, must, according
to specifications, contain 95 per cent of jute butts and 5 per cent of
day. The cheaper forms of confectionery are very heavily adulter-
ated with this material.
Alum clay. — A large quantity of clay is used for making alum.
A rich clay is needed for this purpose.
The white clay of Gay Head and Chilmark, Martha's Vineyard,
Massachusetts, was at one time used extensively for alum-making,
according to Edward Hitchcock.'
As a substitute for sand in making mortar and concrete, clay is
perhaps the best material to be found. For this purpose the clay b
burnt so that it is produced in small irregular pieces that are very
hard and durable. These pieces are then ground to a fairly fine
powder, which is mixed with the lime or cement as sand would be.
The result is a very strong mortar, in some cases stronger than when
sand is employed.^
The so-called gumbo clays, sticky, tough, and dark-colored
clays of the Chariton River region, Missouri, are hard burned and
used for railroad ballast and macadam.
Under the names of Rock Soap and Mineral Soap there have from
time to time been described varieties of clay which, owing to their
feeling, are suggestive of soap, and which in a few instances have
been actually used in the prparation of this material.
A rock soap from Ventura County, California, has be«i described
by Prof. G. H. Koen^ as a mixture of sandy and clayey or soapy
material in the proportion of 45 per cent of the first and 55 per cent
of the second. The chemical composition of the material and of
the two portions is given below:
' ' American Journal of Science, XXII, 1S33, p. 37.
■ The World's ProgieM, February, 1S93.
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Crude
S»ndy
portion.
Soapy
JKMtlOn
67-55
"■97
111
13.67
69^0
Trace
4-55
73 'o
iNotdc
minrd.
670
Alumina and iron
Nearly all the silica is in a soluble or opalescent state
and the aliunina either a hydrate or very basic silicate. It
is said^ that at one time the material was made into a variety of
Tiseful articles, as "salt water soap," scrubbing and toilet soap,
tooth powder, etc.
A somewhat similar material from Elk County, Nevada, has
been used for like purposes, and put upon the market under the
name of San-too-gah-choi mineral soap. This clay is of a drab
color, with a slight pinkish tint, a pronounced soapy feeling and
slight alkaline reaction when moistened and placed upon test paper.
An analysis by R. L. Packard in the laboratory of the U. S. National
Museum yielded:
Silica
Alumina...
Iron oiidei.
Magnena..
Soda
Potash
Ignition...,
Total,
Mention may be made here also of the material sold in the shops
under the name of Bon Ami, and used for cleansing glass and other
like substances. This under the mictoscope shows abundant ml-
■ Sixth Annual Report of the State Mineralogist of California, 1S86, Pt. i, p. 139.
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346 THE NON-METALUC MINERALS.
nute sharply angular particles, consisting of partially decomposed
feldspar mixed with a completely amorphous mineral which may
be opalescent silica or possibly a very finely comminuted pumice.
An analysis by R. L. Packard yielded:
CosMinusiti.
PerCoiL
S9.86
18.74
9-34
10.70
MajDDcaia
Total ,
■«,.«■
Alcohol extracts 7.43 per cent, and water 0.244 per cent in addi-
tion, the extract having a soapy appearance and the odor of some
essential oiL
A peculiar soapy clay found in Albany, Crook, Weston, and
Natrona Counties, Wyoming, has been shipped in considerable
quantities during the past few years to Philadelphia, New York,
and Chicago, where it was sold under the name of Bentonite at
prices varying from $5.00 to $25.00 per ton. It is stated ' to have
been used in paper manufacture, as a packing for horses' feet; for
a time as a soap in one of the local railway hotels, and in the mak-
ing of "antiphlogistine," a substance widely used in the West in the
form of a plaster applied to the chest in cases of pneumonia or
croup. It has been suggested as admirably suited for use as a
"retarder" for, the hard-finish plasters now coming into use for
This clay is regarded by T. B. Read as originatmg through the
decomposition of the feldspar labradorite occurring in the anor-
thosite of the Laramie Mountains. The chief physical charac-
teristic, aside from its soapy feelmg, is its enormous absorptive
power, the absorption being attended naturally with an increase
' Engiaeering and Mining Jounial, LXIII, 1897, p. 600, LXVI, 1S98, p. 491, and
LXXVl, 1903, p. 48.
ovGoo'^lc
SIUCATES.
247
in bulk amounting to several times that of the original mass.* Plate
XXV, Fig. I, shows the extreme fineness and homogeneity of this
clay as seen under the microscope.
The reported analyses are as follows:
SiO,
ALO,
Fe,0,
MgO
CaO
Na,0,K,0. ,
SO
The analyses given on the following p^es, compiled from works
believed to be authoritative, show the varying character of clays,
so far as their chemical composition is concerned. In many of
these analyses, it will be observed, the silica existing in the form
of quartz is given a separate column from that combined, while
in column 4 is given the calculated percentage of kaolin which the
analyses seem to indicate each sample contains.
' A small plug of ihis clay filled lo accurately occupy a space o£ 30 cubic centi-
meters in the bottom of a conical measuring-SH.sk. and kept saturated with w»ter for
two days, swelled to a bulk of 160 cubic centimeters. The iil»orption wasso com'
plcte that none of Ihe water ran oS when the Hask was inverted, and the condition
of the cby resembled that of Sour or starch paste.
ovGoo'^lc
THl
A
on-MET^utc
i I i
MINERALS.
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»SO 7HE NON-METMUIC MINERALS.
The bibliography of clays is very extensive, and but a few refer-
ences are given here. The reader is referred particularly to Branner's
Bibliography of Clays and the Ceramic Arts,' and to the papers of
Dr. H. Ries in the reports on the Mineral Resources of the United
States, published annually by the U. S. Geological Survey.
S. W. Johnson, John M. Biake. Od Kaolmitc and Pholeiite.
Americtui Journal of Science, XLIII, 1867, p, 351.
J. C. Smock. The Fire Clays and associated Plastic CUys, Kaolins, Feldifwn, and
Fire Sands of New Jersey.
Transactions of the American Institute of Mining Engineers, VI, 1B77, p. 177.
Gbokce H. Coos. Report on the Clay Deposits of Woodbridge, South Amboy, and
other places in New Jersey.
Geological Survey of New Jersey, 1878.
RiCHAKD C. Hills. Koolinite, from Red Mountain, Colorado.
American Journal of Science, XXVII, 18S4, p. 471. See also Bulletin No. ao,
U. S. Geological Survey, 1885, p. 97.
J. P. Lesley. Some general considerations respecting the origin and distribution of
the Delaware and Chester kaolin deposits.
Annual Report Geological Survey of Pennsylvania, 1SS5, p. 571.
J. H. Collins. On tbe Nature aod Origin of Clays; The Composition of Kaolinite.
Mineralogical Magazine, VII, December, 1887, p. 205.
Americin Journal of Science, XLII, 1891, p. ii.
Edwabd Ohtom. The Clays of Ohio, Their Origin, Composition, and Varieties.
Report of the Geoti^cal Survey of Ohio, VII, 1893, pp. 45-68.
Edwabo Okton, Jr. The Clay Working Industries of Ohio.
Report of the Geological Survey of Ohio, VII, 1893, pp. 69-354.
H. O. HoFMAN, C. D. Deuond. Some eiperiments for Determining the Refractori* •
nesB o( Fire Clays.
Transactions of the American Institute of Mining Engineers, XXIV, 1894, p. 4a.
W. Mavnasd Hutcbings. Notes on the Composition of Clays, Slates, etc., and on
some Points in their Contact-Meiamorphism.
The Geological Magazine, I, 1894, p. 36.
H. Jocmju. The Relation between Compodtion and Refractory Characters in Fire
CUys.
Minules of Proceedings of the Institution of Civil Engineeis, CXX, 1894-95,
P- 43'-
Hkinbich Ri£s. Clay Industries of New York.
Bulletin No. \2 of the New York State Museum, III, March, 1895, pp. 100-363.
JOBM Caspeb Branker. Bibliography of Clays and the Ceramic Aits.
Bulletin No. 143, U. S. Geological Survey, rSgfi.
W. S. Blatchley. a Preliminary Report on the Clays and Clay Industries of tbe
Coal and Cbal-Bearing Counties of Indiana.
The School of Mines Quarterly, XVIII, 1S96, p. 65.
W. Maynakd Hutchincs. Clays, Shales, and Slates.
Tbe Geological Magazine, 111, 1896, p. 309.
■ Bulletin No. 143, U. S. Geok^ical Survey, 1S96.
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SIUCATES. 351
Chas. F. Mabeky, Otis T. Flooz. Composition of American K&oUns.
Journal of the American Chemical Society, XVlIt, 1S96, p. 909.
— Clay, Bricks, Pottery, etc,
lliirteentb Report of the Catifomia Stale Mineralogist, 1S96, p. 619.
Thomas C. Hopkins. Clays and Clay Industries of Pennsylvania.
Appendix to the Annual Report of the Pennsylvania State College for 1S97.
Hbihbich Ries. The Clays and Clay-Workiag Industry of Cobrado.
Transactions of the American Institute of Mining Engineers, XXVII, 1897,
P- 336.
H. A, Whekixr. Clay DepoMts.
Missouri Geological Survey, XI.
Heinsicb Ries. Physical Tests of New York Shales.
Scho61 of Mines Quarterly, XIX, 1S98, p. igi.
The Ultimate and the Rational Analysis of Clays and Their Relative Advan-
tages.
Tiaosacttons of the Amerion Institute of Minii^ Engineers, XXVIII, 1898,
G. E. Ladd. Preliminary Reports on Chys of Georgia.
Bulletin No. 6A, Geological Survey of Georgia, 1S9S.
HziNKiCB Ries. Preliminary Reports on Clays of Alabama.
Bulletin No. 6, Geological Survey of Alabama, 1900.
Clays and Shales of Michigan.
Vol. VIII, Fart I, Geological Survey of Michigan, 1900.
Clays of New York.
Bulletin No. 35, Vol. VII, New York Stale Museum, 1900.
E. R. BrcELEV. The Clays and Clay Industries of Wisconsin.
Bulletin No. 8, Wisconsin Geological and Natural History Survey, 190I.
L. DE Laiinay. Observations sur les Kaolins de Saint Yrieun.
Annales des Mines, Vol. Ill, Part I, 1903, p. 105.
Eakle Sloan. A Preliminary Report on the Clays of South Carolina.
South Carolina Geological Survey. Bulletin No. i. Series 4, 1904.
Gebald Francis Lahghlin. The Clays and Clay Industries of Connecticut.
State Geological and Natural History Survey, Bulletin No. 4, 1905.
Jaues H. Gardner and others. Some Kentucky Clays, including Kaolinitic, Flattie,
and Fire Clays.
Kentucky Geological Survey, Bullclin No. t, 1905.
A. G. Leonard and others. [Clays of North Dakota.]
State Geological Survey of North Dakota, Fourth Biennial Report, r9o6.
John T. Porter and others. Investigations relating to Clay and Clay Products by
the U. S. Geological Survey in 1906.
U. S. Geological Survey, Bulletin No. 315, Contributionsto Economic Geology,
1906, pp. 368-355.
H. Ries. Clays, Occurrences, Propertiesand Uses. Wiley & Sons, New York, 1906.
John C. Branner. The Clays of Arkansas.
U. S. Geological Survey, Bulletin No. 351, 1908.
Harrison Everett Ashley. The Colbid Matter ot Clay and its Measurement.
U. S. Geological Survey, Bulletin No. j88, 1909.
Otto Veatch. Second Report on the Clay Deposits of Georgia.
Geological Survey of Georgia, Bulletin No. 18, 1909.
ov Google
352 the non-metaluc minerals.
1 6. fullers' eabth.
The name fullers' earth is made to include a variety of day-like
materials oi a prevailing greenish-white or gray, olive or olive-green
or brownish color, soft, and with a greasy feel. When placed
in water such fall into powder, imparting a dlght murkiness to
the liquid, but do not become plastic to the same extent as the
ordinary clays.
For a long time the principal source of fullers' earth was Eng-
land, but an increased demand has resulted in the discovery of
large quantities on American soil, the more important localities
thus far developed being Bakersville, California; Gadsden County,
Florida, and Custer County, South Dakota. The more important
foreign sources are Bala, in North Wales, and Buckingham and
Surrey, in England.
The celebrated beds at Nutfield, near Redhill, Surrey, England,
occur in Cretaceous formations, a section of which is here given.*
Folkstone beds, gray and iron shot sand 15 ft.
r Buff sandy clay with greensand 15 "
Soft sandstone 4 "
^^bS 1 Greenish sandy clay J "
Sandstone 12 "
I Fullers' earth 8 "
The fullers' earth bed sometimes reaches a thickness of 13 feet.
The upper portion is, as a nde, oxidized to a brownish color by
the action of percolating water, the lower portion being blue. In
addition to the analyses given on p. 254 the following are of interest
as showing the relative amounts of soluble and insoluble matters.'
BLUE EAKTH. (Diied at ido° C.)
Iniolubls Roidue.
Insoluble residue 69^6%— fSiO,,... baAi%
Fe,0, i-|8% AljO,.... 3.46%
A?0. 3.46% Fe,0,. .. i.yM
CaO 5.87% CaO 1.53%
M^ 1.41% iMgO.... 0.86%
P.O, 0-27%
SO^. 0.05% 69^,6%
N»C1 0.05%
K,0 0.74%
H,0 (combined) iS-S7%
* H. B. Woodward, Geology of England and Wales, p. 371.
) F, G. Sanford, Geological Magasine, Vol. VI, 1SS9, pp. 456 and ss6.
ov Google
'Fic. I.— Fuller's Earth Pit, Quincy, Florida.
[After H. Ries: Clays, Their Properties and Uses,]
, 3.— Phosphate Pit, Florida.
[From a Photograph.]
PLATE XXIV.
[Facing page 25?;]
b Coogic
J, Google
YXIXOW EABTH. (Dried at loo" C.)
Insoluble residue.
Fe,0,.
ALO,.
CaO.
When examined with a microscope this material is found to
consist of extremely irregular corroded particles of a siliceous min-
eral which in its least altered state is colorless, but which in nearly
every case has undergone a chloritic or talcosc alteration whereby
the particles are converted into a faindy yeilowish-green product
ahnost wholly without action, on polarized light. These are of all
sizes up to 0.07 mm. The larger portion of the material is made
up of particles fairly uniform in size and about the dimensions
mentioned. In addition to these are minute colorless fragments
down to 0.01 mm. in diameter, and even smaller.
The minute size of these colorless particles renders a determina--
tion of their mineral nature practically impossible, but the outline
of the cleavage Qakes is suggestive of a soda lime feldspar. The
h^ percentage of silica in the insoluble residue would indicate
the presence of a considerable amount of free quartz. This, how-
ever, the microscope only partially substantiates, very few of the
particles showing the brilliant polarization colors characteristic of
this mineral. (See Plate XXV, Fig. 2.)
The Gadsden County, Florida, earth is a light-gray material,
often blackened by organic matter, and shows under the micro-
scope the same greenish, faintly doubly refracting particles, as does
the English, intermixed with numerous angular particles of quartz.
This earth is quite plastic and sticky when wet. A section of-
the beds at the pits of the Cheesebrough Manufacturii^ Com-
pany, as given in The Mineral Resources for 1895-96, is as
follows:
ov Google
254
THE NON-METALUC MINERALS.
Soil i8 ins.
Red clay 3 ft.
Blue clay 3 "
Fullers' earth 5i "
Sandy blue earth 3 "
Fullers' earth (second bed) Thickness not stated.
The following table ' as compiled by Dr. Ries shows the variable
character of the eartb from different sources:
II
U
III
SiO,
ALO,. ...
Fe,0,....
CaO
MgO. ...
H-0
Na,0. "■
K,0
Moisture.
Total..
?:;:
<a)Po8g.Ann..LXXVIl. iB4I>iC-S«i' (f) I>. Pinnun. analrit-
(6) KUproth. Bdtr.. Vol. IV. iSot. p. »B. U) E. J. Sicderer. uulvit.
(e) Dan*. System of Min., 1893, p. 691. {*) Standard Oil Company'a property, E. J.
(iflGeilde, iSQj.p. in. Riedeicr. ulalyit.
(*) Penny Encyclopedia, XI, Dt. Thompton, (0 Howell property. E. J. Riedenr. analyit.
■lalj-st. (l) Moigan property. E. J. Riederer, aa»ly»t.
Uses. — The material was formerly used almost wholly by fullers
for removing the grease from cloths. It is now largely used in
deodorizing and clarifying fats, oils, and greases. The manufacturers
of lard and cottolene are large consumers. Some 2,000 to 3,000 tons
are annually imported and 25,000 to 30,000 tons produced in the
United States. The value is about $9.00 per ton.
' Sevenleenth Annual Report, U. S. Geological Survey, Part III, 1S95-96, p. S80
jvGooi^lc
PLATE XXV.
Fic, 1, Clay, Atbanj', Wyoming, and Fk;. 2, Fuller's Earth, as Seen under Ihe Mkn^
[U. S. National Museum.] CoOqIc
[Foiiag page 354]
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NIOBATES, TANTALATES, AND TUNGSTATES. 255
Vn. NIOBATES, TANTALATES, AND TUNGSTATES.
I. COLUMBITE AND TANTALITE.
These minerals are columbates and tantalates of iron and man-
ganese, columbite representing the nearly pure columbate and
tantalite the nearly pure tantalate. Both are likely to carry varying
quantities of iron and manganese. The analyses given below will
serve to show the varying composition, No. I being columbite from
Greenland, No. II from Haddam, Connecticut, and Nos. Ill and
IV from the Black Hills of South Dakota:
Conttituenw.
I.
II.
III.
IV.
77-97
51 -53
13s*
4-SS
54-09
7-07
29.78
H
■ja
With trace* of tin. wolfnni, lime. nugneiU, etc.
The minerals are of an iron-black, grayish, or brownish color,
opaque, often with a bluish iridescence, dark-red to black streak,
specific gravity varying from 5.3 to 7.3 and hardness of 6. In-
soluble in adds.
Occurrence. — Columbite occurs in granitic and feldspathic dikes
in the form of crystals, crystalline granules, and cleavable masses.
In the United States it has been found in greater or less abundance
in nearly all the States bordering along the Appalachian Mountain
system, in the Black Hills of South Dakota, and also in California
and Colorado. It has also been found in Italy, Bavaria, Finland,
Greenland, and western South America. Tantalite occurs under
similar conditions.
Uses. — The material is used only in the preparation of salts of
columbium and tantaliimi, and is in but httle demand, except for
mineralogical specimens.
2. YITROTANTALITE.
This name is given to a mineral closely related to samarskite (see
next page), but carrying smaller percentages of uranium and lacking
ovGoO'^lc
356
THE NON-METALLIC MINERALS.
in didymium and lanthanum. It is essentially a tantalate of yttrium
with small amounts of other of the rarer earths. In appearance
it is distinguished from samatskite only with difficulty. Pyrochlore,
fergusonite, aschynite, euxenite, etc., are closely related compounds,
the commercial uses of which have not yet been demonstrated.
3. SAMAKSKITE.
Composition as given below. When crystallized, in the form of
rectangular prisms, but occurring more commonly massive and in
flattened granules. Cleavage, imperfect; fracture, conchoidal;
brittle. Hardness, 5 to 6; specific gravity, 5.6 to 5.8. Luster,
vitreous to resinous. Color, velvet-black. Analyses of North Caro-
lina materials yielded :
I.
n.
111.
IV.
}«^.
54.96
0.16
9.91
0.91
SS»3
0.31
10.96
11.74
I 33
14-49
Trace.
] v.t
17-03
14,07
H46
0-7S
4^5
14-45
3-9S
K?!":;:;;:::::;::;;:;;;;::::
1.2s
«-SS
0.34
0.7a
™-"
■■»*■
99.11
100.36
Localities and mode of occurrence. — ^The only localities of im-
portance in the United States are the Wiseman Mica Mine and
Grassy Creek Mine, in Mitchell County, North Carolina. At the
Wiseman Mine large masses, one weiring upwards of 30 pounds,
were found some years ago. The analyses quoted above were
made from material from this mine.^ The mineral has also been
found in Rutherford and McDowell counties.
Uses. — See under Monazite, p. 298.
■ See Minerals of North Carolina, Bulletin No. 74, U. S. Geological Survey,
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NIOBATES, T^NTALATES, AND TUNGSTATES. aS7
4. WOLFSAUITE, HUBNERITE, AND FERBERITE.
Composition. — Wolframite is a tungstate of manganese, and iron.
The proportions of the iron and manganese are quite variable, the
tungsten remaining nearly constant The name hiibnerite is given
to the variety containing very litde iron, but consisting essentially
of tungsten and manganese. Ferbente is the theoretically pure
ferrous tungstate. The following table shows the range in com-
position:
LocUty.
WO2
FeO.
MnO.
CmO.
MgO.
Wolfmmilc:
75-55
75-47
■ 76-33
74.88
74.13
»".3'
9-S3
3-81
o.se
>3-'S
iS,
19.73
"3.87
0.56
0.16
Hiibnerite:
Bonila, New Mexico
Nye County, Nevnda
0.13
0.14
l.aS
Trace.
0.08
These are all dark reddish brown to black in color, with a
resinous luster; a hardness of about 5, a specific gravity of 7.55,
and a pronounced tendency to cleave with flat, even surfaces. The
great weight, color, and cleavage tendencies are strongly marked
characteristics, and the minerals once identified are easily recognized.
Occurrence.— The timgstates are found, as a rule, m veins, often
associated with tin ores, and also with quartz, pyrite, galena, and
sphalerite. The principal known localities in the United States
are Boulder and Gilpin counties, Colorado; Monroe and Trumbull
counties, Connecticut; Blue Hill Bay, Maine; Rockbridge County,
Virginia; Mecklenburg County, North Carolina; The Black Hills,
South Dakota; Stevens County, Washmgton; Russellville, Arizona;
Nye, Lanier, and Osceola counties, Nevada; Lincoln County, New
Mexico; Falls County, Texas. Wolframite has been also reported
from Oregon, Montana, and Idaho. The principal foreign, localities
are the tin regions of Cornwall, England; Bohemia, Saxony, and
Autsralia. Itbalsofoimd inPeru,Bolivia,andtheArgentineRepublic.
In the Black Hills regbn of South Dakota wolframite, ac-
cording to J. D. Irving,' occurs in connection with a crystalline
' Transaclions of the American Institute of Mining Engineers, XXXI, 1901,
p. 6S1.
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as8 THE NON-METALLIC MINERALS.
dolomite lying between shales above and quartzite and auriferous
gravels below. The dolomite is often highly siliceous, and passes
at times through the intermediate stage of a dolomitic sand rock
into quartzite, the silicification in such cases seeming to have
been contemporaneous with the formation of the ore body. The
wolframite itself occurs in flat, horizontal but rather irregular masses
of all thicknesses up to 2 feet. Such frequently cover considerable
areas, but are so extremely irregular that it is difficult to fonn exact
estimates of their extent.
The ore bodies are intimately associated with the flat masses
or chutes of refractory siliceous gold ore, which has been so ex-
tensively developed of late years in this region, and which consists
of an extremely hard, brittle rock, composed chiefly of secondary
silica, carrying pyrite, fluorite, barite, and occasionally gypsum.
In the areas where the wolframite is found the siliceous ore is always
oxidized and is usually coarse in texture. The ore is generally
banded, the banding being continuous with the bedding planes of
the adjoining strata, and the chutes occur along lines of fracture
termed verticals, on either side of which the dolomite has been
replaced for a distance varying from a fraction of an inch up to 12
feet.
Investigation of the ore bodies of this type shows that they are
replacements of the dolomitic beds by silica, pyrite, and other min-
erals, the mineralizing waters having gained access to the soluble
beds through the fractures above mentioned. At times the wol-
framite forms a rim around the outer edge of the siliceous ore chutes,
often extending inward and upward so as to form a thin capping
for the ore. It thus appears as a sort of envelope to the siliceous
ore mass which it incloses on all except the lower sides. Margins
of this kind are often 2 to 2^ feet thick, though the capping portion
is usually thinner. At other times the wolframite occurs in ir-
regular masses scattered through the siliceous ore or in stringers
and thin contorted layers in the partially silicified dolomite. In
general the ore is separated from the non-mineralized rock by a
fairly sharp line of demarkation, but in many instances it grades
off so that the ore becomes leaner and passes, by almost impercep-
tible gradations, into the country rock.
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NIOBATES, T^NT^LATES, ^ND TUNGST^TES.
^5?
As taken from the mines the wolframite is a dense black massive
rock, of fine granular texture and, of course, great weight, closely
resembling a fine-grained magnetite, but having a greater specific
gravity and slightly brownish streak. An analysis of this ore, as
made by W. F. Hillebrand of the U. S, Geological Survey, is given
below and also a calculation made from these analyses to show
the proportions of the principal minerals contained therein.
As to the source of the ore in these deposits there is some ques-
tion, but it is thought most probable by Irving that circulating
waters permeating the Algonkian rocks below brought the material
to its present position, where it was deposited through a process of
metasomatic interchange; this being true, this particular deposit
would belong to the category of what are known as secondary.
Wolframite, it should be stated, is also found at the Etta Tin Mines
and at Nigger Hill in the southern portion of the Black Hills, but
under totally different conditions, being here a constituent of the
pegmatite, and hence a primary mineral.
ANALYSES OF BLACK HILLS
WOLFHAMITE ORE.
ConititueDts.
I.
II.
SiO
PtrCtoC
W.87
IS
0-93
o!o8
o.87t
'■'5
T^ce.
Trace.
Percent.
9.60
61.70
...67*
iaSa/"^'//^'^'^'^'^'^:'.'.'.
7.11
S-39
ft.."^
^ot ::::;::;::.::::
0.10S
99.64
AuBya of I.— Gold, o.oj m. per ton; nl
Extremely minute truei of Mg, Zn, Cu
■ Determined M Pefit, indudei FcO.
tUpto los-C
ov Google
THE NON-METALUC MINERALS.
L UIHKBALS.
Consiiiuents
I.
II
Wolframite (FeMn)O.WO ....
"■54
3-85
I.2S
1.34
.;.68
According to State Commissioner of Mines Harry A. Lee,
wolfram occurs in several counties in Colorado. In Boulder and
Gilpin counties it has been found in a complex of granite, gneiss,
and schist, where it occurs in small pockets or streaks disseminated
through fissure veins.
R. D. Geoi^e states' that the ore is largely in the form of
ferberite, and the majority of the veins are in granite, though a number
of good producing mines are close to the contact between the granite
and gneiss, and in some instances in the gneiss itself. The veins,
however, seemingly, decrease in productiveness or become quite
barren in the more schistose varieties of the rock. Throu^out
the various areas the veins have no constant trend, the angle of
dip is generally steep, often vertical, and rarely falling below 45°.
The conditions of vein formation and filling, as outUned, are as
follows:
(i) A period of earth movements in which fissures were formed,
some of which follow the pegmatite and granite dikes, while others
cut the country rock. At the close of the movements these fissures
were left partially filled by loose masses of angular rock fragments.
(2) Silica-bearing waters, probably at high temperatures, ihea
circulated through the rock fragments in the fissures, and by a
process of replacement feldspars and biotite in the rock fragmmts
were slowly dissolved out and silica in the form of chalcedony-like
quartz or homstone deposited in their place. Locally a small
deposition of ferberite accompanied this replacement.
(3) This was followed by a second perkxi of earth movements
' First Report Cobiado Geological Survey, 1908, p. 60.
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NIOB^TES. T^NTALATES, AND TUNCSTATES. a6i
in which the vein breccia, and in places the country rock itself was
crushed and mingled into a new mass of fragments. This movement
was accompanied by a considerable vertical displacement and drag-
ging along the walls of the veins.
(4) This period was followed by the most important deposition
of tungsten. The heated waters, loaded with tungsten salt, rose
toward the surface and deposited the ferberite in the interstices of
the rock fragments. In places more or less silica was deposited
with the ferberite.
(5) Then followed a third movem^t which crushed the vein
filling and added more of the dike rock or country rock to the frag-
mental mass. This was followed by (6) a second considerable
deposition of homstone silica, and this in turn by (7) a second period
of tungsten deposition. Following this there were (8) contempora-
neous depositions of silica and tungsten ore and (9) local solutions
of the tungsten and deposition of silica, possibly producing a sec-
ondary enrichment
Formed at these various periods there is naturally considerable
diversity in the ores. Professor George has grouped them in three
rather well-deGned forms which frequ^illy grade into one another.
These are (i) well-crystallized crusts and layers covering the sur-
face of the rock fragments and cementing them into a breccia;
(2) massive, granular ore showing few or no crystal faces and oc-
curring as more dense seams and masses in the wider and less brec-
ciated portions of the veins, and (3) a highly siliceous ore in which
the berberite is in fine grains, sometimes showing crystal forms, and
scattered throughout homstone or cryptocrystalline quartz.
The following analyses of material from the Nederland-Beaver
Creek area of Colorado, as given by George, are sdected as showing
the average composition. The CaO is r^arded as belonging to
admixed scheelite, while the silica, alumina, and magnesia are
present as impurities and non-essential:
WO..
FeO.
HnO.
CO,
SiOt.
AbO..
MgO.
Clyde Mine
Lo« Chance
6.. IS
74. 1 J
'9-33
19.90
aj.is
:5
o.3»
16.10
14.68
0.76
a.4!i
1.34
0.46
0.39
Manchester Lake
J, Google
262 THE NON-METALLIC MINERALS.
In Osceola County, Nevada, tungsten in the form of hubnwite
occurs in veins varying from 6 to 36 inches in width, and having
a strike north 70° east and a dip of 65" northwest The veins are
in granite with a well-defined selvage and carry quartz as the prin-
cipal gangue.
The hiibnerite is found in crystals and masses with very pro-
nounced cleavage planes from 2 to 4 inches in length and r to 3
inches in width. It also occurs in fine grains and irregular bodies,
the quartz and hiibnerite having apparently been deposited con-
temporaneously. In a few instances scheelite has been found as-
sociated with the hiibnerite. A little pyrite and tiuorite are also
occasionally met with. The ore is stated to have averaged from 65
to 70 per cent of WO3.'
In Arizona, tungsten ore, also in the form of hiibnerite, occurs,
according to W. P. Blake, in the granite hills of the Dragoon Moun-
tains, about 6 miles north of Dragoon Summit Station on the
Southern Pacific Railway in Cochise County.
The veins here are nearly vertical and generally traverse the
granite gneiss in the direction of the rude structural bedding planes.
They are from a few inches to 2 or 3 feet in width. The gangue
material is quartz, throughout which the hiibnerite occurs, some-
what irregularly disseminated, sometimes in patches or bunches
centrally disposed with quartz on either side, and sometimes dis-
seminated from side to side or in layers or bunches in close contact
with the continuous walls. The hiibnerite itself is in the form of
large tubular blocks or thick plates, often with a somewhat radial
arrangement, penetrating the solid gangue of white quartz. Masses
of all sizes up to 500 pounds in weight have been reported. The
color of the mineral is light brownish red, thin films or plates seen
by transmitted light being of a ruby-red color. Aside from quartz,
which forms the prevailing gangue mineral, the presence of a little
fiuorspar and mica has been noted.
A. M. Finlayson describes ^ tungsten ores, both wolframite and
' Fred. D. Smith, Engineering and Mining Journal, March i, 190s, p. 304; F.
B. Weeks, list Annual Report al the V. S. Geok^cal Survey, i8g9-i9<xi, Part VI,
P- 319-
' Geological Magazine, January, 1910, p. 30.
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NIOBATES. TANTj4LATES, AND TUNGSTATES. B63
scheelite, occurring in small veins in a post Silurian "greisen" in
Carrock. Fell. This greisen is regarded as an acid modification of
the Skiddaw granite, the feldspar of the normal rock having almost
wholly disappeared, and a white mica (gilbertite) replacing the biotite,
leaving a quartz muscovite aggregate comparable with the greisen
of the Saxon mines and having some points in common with the
beresite of the Russian Urals and the alaskite of J. E. Spurr. The
veins consist essentially of the quartz and white mica motioned
with a pale bluish-green apatite. There is a complete absence of
tourmaline, fluorite or other minerals indicative of pneumotolitic
action. The wolframite, with a less amoimt of scheelite, is dis-
seminated irr^ularly in bunches through the vein. Some arseno-
pyrite is present and also molybdenite.
Uses. — See under Scheelite, below.
5. SCHEELITE. *
Thb is a calcium tungstate, consisting when pure of some 80.6
per cent tungsten trioxide (WO3) and 19.4 per cent lime; usually,
however, carrying from i to 8 per cent of molybdic oxide (M0O3).
The mineral is white and translucent, sometimes yellow and brownish
in color, with a hardness of 4.5-5, gravity 6, and a 'tendency to
cleave into octahedral forms.
Scheelite is much less common in its occiurence than wolfram
and few localities of any apparent commercial importance have
thus far been reported.
A deposit that at one time seemed promising was discovered
some years ago near Long Hill Station 00 the Housatonic Railroad
in TrumbuU Parish, Fairfield County, about 8 miles from the city
of Bridgeport The country rock is a metamorphic amphibolic
gneiss of a dark, blackish color, overlying a crystalline limestone,
and this in turn overlying a second homblendtc gneiss, the main
mass of the ore being segregated along the line of contact betweoi
the limestone and the homblendic gneiss, the latter being considered
as an altered igneous rock and the deposit as a whole, therefore, a
contact deposit
In the main opening the fresh contact rock between the gneiss
ov Google
264 THE NON'METALUC MINERALS.
and the limestone is a massive quartz-zoisite-epidote-homblende
rock, throughout which the scheelite is irregularly disseminated
and often scattered in crystalline masses which are sometimes as
large as one's fist. Associated with the scheelite is more or less
pyrite, and numerous crystals of wolframite which are, however,
in all cases pseudomorphous.
A considerable amount of capital has been expended in prospect-
ing and in the erection of works for concentrating, but, so far as
the present writer has information, a comparatively small amount
of pure scheelite has thus far been produced.
Scheelite has been found in some quanti^ in gold-bearing veins
of the Minnehaha mine in Kem County, California. Two "shoots"
of the ore are stated to occur in the veins, the full width of which
is from 18 to 20 inches. The hanging wall Is of mica schist and the
footwall of limestone.' Scheelite is also known to occur in quartz
veins cutting diorite at AtoUa. in San Bernardino County, this same
State.
Recent reports from the Canadian Department of Mines ^ indi-
cate that the mineral is by no means of rare occurrence in Nova
Scotia, British Columbia, and other parts of the dominion. It is
found in small, disconnected, lenticular masses, sometimes forming
a third -or fourth of the filling matter in gold-bearing quartz veins
in Halifax County, Nova Scotia. The veins are in slate, of all
widths up to 23 inches, approximatdy parallel, and all in a
belt not more than 100 yards in width following the strike of
the slate, which is here east and west, with a dip of 80* toward
the north. Arsenopyrite is a common associate. In the Barker-
ville district of British Columbia scheelite occurs associated with
iron pyrites and galena in small quartz veins and vugs in mica
schist.
Vses. — ^Tungsten is used mainly in the manufacture of the
so-called self-hardening steel, the material being introduced either
as a ferro-tungsten or as the powdered mineral. This tungsten
steel is said to be particularly adaptable to the manufacture of
' The Mining World, Mar. 31, 1906. p. 414.
• Report on Tungsten Ores of Canada, by T. L, Walker, 1909.
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mOBATES, TANTALATES, AND TUNGSTATES. 265
cutting tools, which can be used even when heated to temperatures
that would destroy the temper of the ordinary carbon steel. Its
consideration in this connection belongs properly to works on
merallurgy. It is also used in the preparatbn of tungstic acid and
sodium tungstates, and attempts have been made to utilize it in
porcelain glazes, though thus far without much success.
The production of tungst^ ore of all kinds in the United States
during 1908 amounted to some 497 short tons of concentrates,
valued at $126,238. The price of the tungsten metal in igoi varied
from 58 to 64 cents per pound, of the ferro-tungsten from 27 to 31
cents per pound. The price of the ore during 1906-08 ranged
from $254 to $487 per ton, the ores, as a rule, carrying from 60
to 75 per cent of WO.' Prices are based upon the per cent of
tungstic oxide, the concentrates being sold by the "unit" of i pet
cent, or 20 pounds per short ton.
BIBLIOGRAPHY.
J. Prut TIP Tungsten Broozcs.
Joumsl of ihe Society of Chemical Industiy, I, 1881, p. 153.
The Use of Wolfram ot Tungsten,
Iron Age, XXXIX, 1887, p. 33.
T. A. RitJKAKD. Tungsten.
Engineering and Mining Journal, LIII, 1893, p. 448.
Wolfram Ore.
Iron Age, XL, 1893, p. lag.
Adolf Gusi.t. On a Remarkable Deposit of Wolftam Oie in the United States.
IHiuactions of the American Institute of Mining Engineers, XXII, iSgj,
p. 336.
HxNXi MoiSSAN. Researches on Tungsten.
Minutes of the Proceedings of Ihe Instilutbn of Civil Engineers, CXXVI,
1895-96, p. 481.
R. HzLMHACKEK. Wolfram Ore.
Engineering and Mining Jounwl, LXII, 1896, p. 153.
Prof. BoDEKBENDEK. Wolfram in the Siena de Cordoba, Aifentine Repubtic.
Transactions of the North of England Institute of Mining and Mechanical
Engineers, XLV, Ft. 3, March, 1896, p. 59.
Wu. P. Blake. Htibnerite in Arizona.
Transactions of the America Institute of Mining Engineers, XXVIII, 1898,
P- S«-
* Tbtae figures are taken bom the Mineral Industry for 1901,
ovGoo'^lc
a66 THE NON-METALLIC MINERALS.
F. B. Weeks. An Occurrence of Tungsten Ore in Eastern Nevada.
aist Annual Report of the U. S. Geological Survey, 1899-1900, Pt. VI.
FizD D. SuiiH. The Osceob, Nevada, Tungsten Deposits.
Engineering and Mining Journal, LXXIII, March, 1901, pp. 304, 305.
J. D. Irvihc. So:ne Recently Exploited Deposits of Wolframite in the Black Hills
of South Dakota.
Transactions of the American Institute of Mbing Engineers, XXXI, 1909,
pp. 683-685.
W. H. HOBBS. The Old Tungsten Mine at Trumbull, Connecticut.
aid Annual Report of the U, S. Geological Survey, 1900-ot. Part II, p. 13.
This paper gives in addition to description of opcurrence, matter relative to
metbod of mining and concentration.
R. S. Baoerstock. a California Scheelite Deposit.
The Mining World, November 31, 1906; gives also description of method of
R. D. George. First Report of the Geological Survey of Colorado, 1908.
T. L. WALiEBR. Report on Tungsten Ores of Canada, Department of Mines, 1909.
VIII. PHOSPHATES AND VANADATES.
I. apatite; rock phosphate; guano; etc.
Phosphorus is one of the most widespread of the elements, and
is apparently indispensable to both animal and vegetable life. In
nature it occurs in various compounds, by far the more common
being the phosphates of calcium and aluminum, such as are com-
mercially used as fertilizers. These in various conditions of im-
purity occur under several forms, some distinct and well defined,
others illy defined and passing by insensible gradations into one
another, but all classed under the general term of phosphates.
Their origin and general physical properties are quite variable, and
any attempt at classifying must be more or less arbitrary. For
our present purposes it is sufficient that we treat them under the
heads of mineral phosphates and rock phosphates, as has been
done by Dr. Penrose.' Tliesetwo classes are then subdivided as
below;
■Bulletin No. 46 of the U. S. Geological Survey.
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PHOSPHATES.
(t) Minenl phosphates*...
(n) Rock phosphates..
I Pbosphaiic limestones.
Apatite. — Under the name of apatite is included a mineral
composed essentially of phosphate of lime, though nearly always
canying small amounts of fluorine or chlorine, thereby giving rise
to the varieties, fiuor-apaiite and chlor-apaiite. The mineral crystal-
lizes in the hexagonal system, forming well-defined six-sided elon-
gated prisms of a green, blue, yellow, rose, or reddish color, or some-
times quite colorless. It also occurs as a crystalline granular rock
mass. The hardness is 4.5 to 5; speciOc gravity, 3.23; luster, vitre-
ous. Apatite in the form of minute crystals is an almost imiversal
constitu^t of eruptive rocks of all kinds and all ages. It is also
foimd in sedimentary and metamorphic rocks as a constituent of veins
of various kinds, and Is a common accompaniment of beds of mag-
netic iron ores. It is only when occurring segregated in veins and
pockets, either in distinct crystals or as massive crystalline aggre-
gates, as in Canada and Norway, that the material has any great
economic value. The average composition of the apatites, as given
in the latest edition of Dana's Mineralogy, is as follows:
' Fudu (Notes Sur la Constitution des Gtt«i Phosphate de Chaux) dindea the
natural phosphates into three classes. In the first the phosphadc material is concei*-
tiated in sedimentary beds; ia the second it is disseminated throughout eruptive
locks, and in the thiid it constitutes entirely or partially ihe malenal filling vein*
and pockets. That found in sedimentary beds occurs in rounded and concretionary
masses called nodules. In eruptive and metamorphic rocks the phosphate occuis in
the ctTStaltine form ot apatite, sometimes isolated or grouped in aggregates. In
veins the phosphate occurs massive and in pockets, ciystalline, but not in distinct
cr)-5tals; rather as globular and radiating masses. To such the name phosphorite Is
given. The three varieties show a like varialion in solubility, the amorphous phos-
phates being soluble in citrate or oxalate of ammonia to the extent of 30 to 50 per
cent; the phosphorites to the extent of only ij to 30 per cent, and the apatite scarcely
at all. The amorphous phosphates alone have proven of value for direct applicatioii
to mQs. the other varieties needing previous treatment to render them soluble.
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THE NOS-METALLIC MINERALS.
Vsriety.
P^i.
CsO.
F.
a.
Chlor-apatite
Fluor-apatite
42.3
53.8
55-5
"s'i"
6.8
or Ca,P,0„ R^
-4 +CaCl, I0.6.
.^r + CaFp 7-75-
The name pkospkortte covers a material of the .-. ne composi-
tion as apatite, but uccurring in massive concretion ■ :ind mam-
miUary forms. The name was first used by Kirw'an i describing
the phosphates of Estremadura, Spain, which occur in veins and
pockety masses in Silurian schists, as noted later.
Rock Phosphate. — The general name of rock phosphate is
given to deposits having no definite composition but consisting
of amorphous mixtures of phosphatic and .other mineral matter
in indefinite proportions. Here would be included the amorphous
nodular phosphates like those of our Southern Atlantic States,
phosphatic limestones and marls, guano, and bone-bed deposits
These are so variable in character that no satisfactory descripticoi
of them as a whole can be given. The name coprolUe is given to
a nodular phosphate such as occurs among the Carboniferous beds
of the Firth of Forth in Scotland, and is regarded as the fossilized
excrement of vertebrate animals. Phosphatic limestones and marl,
as the names denote, are simply limestones and marls containing
an appreciable amount of lime in the form of phosphate. Such are
rarely sufficiently rich to be of value except in the immediate vicinity
of their occurrence, owing to cost of transportation. Guano is the
name given to the accumulations of sea-fowl excretions, such as
occur in quantities only in rainless regions, as the western coast
of South America. The material is of a white-gray and yellowish
color, friable, and contains some 3o or more per cent of phosphate
of time, lo to 12 per cent of organic matter, 30 per cent of ammonia
salts, and 20 per cent of water. Through prolonged exposure to
the leaching action of meteoric waters, similar deposits in the West
India Islands have lost their ammonia salts and other soluble con-
stituents and become converted into insoluble phosphates, or leached
guanos like those of the Navassa Islands.
Origin and Occurrence. — ^The origin of the various forms of phos-
phatic deposits has been a subject of much speculation. Their
occurrence imder diverse conditions renders it certain that not all
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PHOSPHATES 369
can be traced to a common source, but are the result of difterent
agencies acting under the same or different conditions. By many,
all forms r.rc regarded as being phosphatic materials from animal
life, and owing their present diversity of form to the varying con-
ditions to which they were at the time of formation or have since
been subjected. This, however, as long since pointed out, is an
imcalled-for hypothesis, since phosphatic matter must have existed
prior to the introduction of animal life, and there is no reason to
suppose it may not, under proper conditions, have been brought
into combination as phosphate of lime without the intervention
of life in any of its forms. The almost universal presence of apatite
in small and widely disseminated fonns in eruptive rocks of all
kinds and all ages would seem to declare its independence of animal
origin as completely as the pyroxenic, feldspathic, or quartzose
constituents with which it is there associated. The occurrence of
certain of the Canadian apatites as noted later, in veins and pockets,
sometimes with a banded or concretionary structure and blending
gradually into the country rock, is regarded by some as strongly
suggestive of an origin by deposition from solution, that is, by a
process of segregation of phosphates from the surrounding rock
contemporaneously with their metamorphism and crystallization.
Dr. Ells, of the Canadian survey, would regard those occurring
in close juxtaposition with eruptive pyroxenites as due to combina-
tion of the phosphoric acid brought up in vapors along the line of
contact with the calcareous materials in the already softened gneisses.
This explanation as well as others will perhaps be better understood
in the part of this work relating to localities. On the other hand,
the presence of apatite in crystaUine form associated with beds of
iron ore, as in northern New York, has been regarded by Prof,
W- P. Blake and others as indicative of an oi^anic and sedimentary
origin tor both minerals. Later work has, however, shown that
these ores are probably of igneous origin. The Norwegian apatite
from its association with an eruptive rock (gabbro) has been regarded
as itself of eruptive origin.
The phosphorites, like the apatites, occur in commercial quan-
tities mainly among the older rocks, and in pockets and veins so
situated as to lead to the conclusion that they are secondary products
ovGoO'^lc
370 THE NON-METALLIC MINERALS.
derived by a process of segregation from the inclosing materiaL
Davies regards tlie Bordeaux phosphorites, in the Jurassic lime-
stones of southern France as the result of phosphatic matter de-
posited on the rocky fioor of an
Eocene ocean, from water largely
impregnated with it. Others have
considered them as geyserine
ejections, or due to infiltration
of water charged with phosphatic
matter derived from the bones
in the overlying clays. Stanier,
on the other hand, regards the
phosphorites of Portugal as due
to segregation of phosphatic
matter from the surrounding
granite, the solvent being meteoric
Fig. 40.— Seciian showing apatite de- waters. Such deposits are super-
p«iu«w.nmsf.rfMu»Mi». ^ j^ J [j^^ those por-
(After Cirkel) '^
tions of the rock aflfected by
surface waters.
The origin of the amorphous, nodular, and massive rock phos-
phates can be traced more direcdy to organic agencies. All
things considered, it seems most probable that the phosphatic
matter itself was contained in the numerous animal remains,^ which,
in the shape of phosphatic limestones, marls, and guanos, have
accumulated under favorable conditions to form deposits of very con-
siderable thickness. Throughout these beds the phosphatic matter
would, in most cases, be disseminated in amounts too sparing to
be of economic value, but it has since their deposition been con-
centrated by a leaching out by percolating waters of the more soluble
carbonate of lime. Thus H. LSsne, in writing of the nodular phos-
phates occurring in pockety masses in clay near DouUens (France),
' T. S. Hunt showed, in 1854, that shells of fossil iingulEE were lai^ly phosphatic,
calcined ahelU of L. ovalit yielding 85.79 per cent phosphate of lime. American
Journal ot Science, XVII, 1854, p. 335.
ovGoo'^lc
PHOSPHATES. 271
aigues that the nodules as well as the clay itself are due to
the decalcification of preexisting chalk by percolating meteoric
waters.
In this connection it is instructive to note that phosphatic nodules,
in size rarely exceeding 4 to 6 cm., were dredged up during the
ChaUenger expedition, from depths of from 98 to 1,600 fathoms
on the Aguihas Banks, south of the Cape of Good Hope. These
are rounded and very irregular capricious forms, sometimes angular,
and have exteriorly a glazed appearance, due to a thin coating of
oxides of iron and manganese. The nodules yield from 19.96 to
23.54 per cent P,0(. In those from deep water there are found
an abundance of calcareous organic remains, especially of rhizopods.
The phosphate penetrates the shell in every part, and replaces the
original carbonate of lime.
The nodules are most abundant apparently where there are
great and rapid changes of temperature due to alternating warm and
cold oceanic currents, as off the Cape of Good Hope and the eastern
coast of North America. Under such conditions marine organisms
would be killed in great numbers, and by the accumulation of their
remains furnish the necessary phosphatic matter for the nodules.
It seems probable that the Cretaceous and Tertiary deposits in
various parts of the world may have formed under simitar con-
ditions.
Hughes has described ' phosphatic coralline limestones on the
islands of Barbuda and Aruba (West Indies), as having undoubtedly
originated through a replacement of the original carbonic by phos-
phoric acid, the latter acid being derived from the overlying guano.
The phosphatic guano has, however, now completely disappeared
through the leaching and erosive action of water, leaving the coral
rock itself containing 70 to 80 per cent phosphate of hme.
Hayes* regards the Tennessee black phosphates as due to the
' Quarterly Journal of the Geological Society of London, XLI, 1885, p. 80.
' Sixteenth Annual Report of tlie U. S. Geologkal Survey, 1894-95, Ft. 4, p. 610;
Seventeenth Annual Report U. S. Geological Survey, 1895-96, PC. i, p. ai.
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373 THE NON-METALLIC MINERALS.
slow accumulation on sea bottoms of phosphatic organisms (Lin-
gulie), from which the carbonate of lime was gradually removed
by the leaching action of carbonated waters, leaving the less soluble
phosphate behind. The white bedded phosphates of Perry County,
in the same State, are regarded as a product of secondary replace-
ment— that is, as due to phosphate of lime in solution, replaciog
the carbonate of lime of preexisting limestones, as in the case noted
above. The source of the phosphoric acid, whether frran the over-
lying Carboniferous limestones or from the older Devonian and
Silurian rocks, is not, however, in thi^ case apparent.
TeaU has shown ' that some phosphatic rocks from Clipperton
Atoll, in the northern Pacific, are trach3tes in which phosphoric
add has replaced the original silica. The replacement he r^ands
as having been effected through the agency of alkaline principally
ammonium) phosphate which has leached down from overlying
guano. A microscopic examination of the rock in thin sections
showed that the replacing process began with the interstitial matter,
then extended to the feldspar microlites, and lastly the porphyritic
sanidin crystab. The gradual change in the relative proportion
of silica and phosphoric acid, as shown by analyses of more or less
altered samples, is shown below, No. I being that of the unaltered
rock and II and III of the altered forms:
■
II.
III.
1i
43-7
17.0
11.3
a.8
38-5
13.0
PoV ■;■■■;■■•■
Loss on ipUtfon
From a comparison of these rocks with those of Redonda, in
the Spanish West Indies, it is concluded that the latter phosphates
have likewise resulted from a similar replacement in andesitic rocks.
In this connection reference is made to the work of M. A. Gautier,*
' Quarterly Journal of the Geolog[ca] Society of London, LIV, 1898, p. 230.
' Formation des Phosphates Naturels d'Alumina et de Fer, Comptes Rcndus de
Acad^ie des Sciences, Paris, CXVI, 1S93, p. 1491.
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PHOSPHATES. 2?3
in which he describes the formation of aluminous phosphates throu^
the action of the ammonium phosphate arising from decomposing
organic matter on the clay of the fioor of caverns. (See under
Occurrences.)
The guanos, as noted elsewhere, owe their origin mainly to the
accumulations of sea-fowl excretions. Such deposits when un-
leached, are relatively poor in phosphatic matter and rich in salts
trf ammonia. Where, however, subjected to the leaching action
of rains the more soluble constituents are carried away, leaving
the less soluble phosphates, together with impurities, in the shape
of alumina, silica, and iron oxides to form the so-called leached
guanos of the West India Islands. As stated in the descriptions
of localities, guano deposits are not infrequently of a thickness
such as to cause their origin as above stated to seem well-nigh in-
credible were there not sufficient data acquired within historic
times to demonstrate its accuracy beyond dispute. Thus it is said '
that in the year 1840 a vessel loaded with guano on the island of
Ichabo, on the east coast of Africa. During the excavations which
were necessary the crew exhumed the dead body of a Portuguese
sailor, who, according to the headboard on which his name and
date of burial had been carved with a knife, had been interred
fifty-two years previously. The top of this headboard projected
2 feet above the original surface, but had been covered by exactly
7 feet of subsequent deposit of guano. That is to say, the deposition
was going on at the rate of a little over an inch and a half yearly.
LOCALITIES OF PHOSPHATES.
(i) Mineral Phosphates.
Canada. — According to Dr. Ells, of the Canadian Survey,' the
discovery of apatite in the Laurentian rocks of Eastern Canada was
first made in the vicinity of the Lievre by Lieutenant Ingall in 1829,
though it was not until early in i860 that actual mining was begun.
> R. Ridgmy, Science, XXI, 189J, p. 360.
*The Canadian Mining and Mechanical Review, Mardi, i&gj.
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374 THE NON-METMLUC MINERALS
The mineral occurs in the form of well-defined crystals in a matrix
of coarsely crystalline calcite and in vein-like and pockety granular
masses along the line of contact between eruptive pyroxenites and
LaurentJan gneisses. The first form is the predominant one for
Ontario only, the second for Quebec. From a series of openings
made at the North Star Mine, in the region north of Ottawa, it
appears that the massive coarsely crystaUine granular apatite follows
a somewhat regular course in the pyroxenite near the gneiss, but
occurs principally in a series of large bunches or chimneys connected
with each other by smaller strings or leaders. Sometimes these
pockety bunches of ore are of irregular shape and yield hundreds
of tons, but present none of the characteristics of veins, either in
the presence of hanging or foot walls, while many of the masses of
apatite appear to be completely isolated in the mass of pyroxenite,
though possibly there may have been a connection through small
fissures with other deposits. The lack of any connection between
these massive apatites and the regularly stratified gneiss is evident.
Fio. 41. — Section through apatite and mica deposits. Templeton, Canada.
[After Cirliel.]
and their occurrence in the pyroxenite is further evidence in support
of the view that the workable deposits are not of organic origin,
but confined entirely to ^eous rocks. In certain cases where a
supposed true-vein structure has been found, such can be explained
by noticing that the deposits of phosphates occur, for the most
part at least, near the line of contact between the pyroxoiite and
the gneiss. (Fig. 41.)
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PHOSPHATES. 275
The principal producing fields lie in Ottawa County, Province
of Quebec, and Leeds, Lanark, Frontenac, Addington, and Renfrew
counties, Province of Ontario. The first, which is by far the more
important field, extends from the Ottawa River on the south, in a
northerly direction through Buckingham, Templeton, Wakfefield,
Denholm, Bowman, Hincks, and other townships with an average
width of 15 to 25 miles. It is therefore practically coincident with
the mica (phlogopite) belt. The second lies to the southwest and
extends from the Ottawa for a distance of about 100 miles southerly,
or to within 15 miles of the St, Lawrence. It has a width of from
50 to 75 miles.
Davies gives the following table as showing the average composi-
tion of the Canadian phosphates:
Conitituenu,
I.
U.
III.
IV.
V.
VI.
Moisture, water of comblnalioo, and loss
o.6i
^7-83
41-54
54-74
303
0.S9
4-J9
1.09
30-84
4»-73
'3-3*
i»-03
0.89
13-15
10.17
..83
31.87
43-6>
9-»8
13-So
rnwpnoncaaa
Oxide of iron, aluminat fluorine, etc. ...
100.00
73-'5
9o!6S
'T^Z
100.00
67-3^
71. QI
f^iS
Norway. — The principal apatite fields He along the coast in the
southern portion of the peninsula between Langesund and Arendal.
The material occurs in crystals and crystalline granular aggregates
of a white, yellow, greenish, or red color in veins and pockets em-
bedded in the mass of an eruptive gabbro, near the line of contact
of the gabbro and adjacent rocks, in the country rock itself in the
immediate vicinity of the gabbro, and in coarse pegmatitic veins
which are cut by the gabbro. The largest veins are in the mass
of the gabbro itself or near the line of contact. Where the apatite
occurs in the gabbro the latter is, as a rule, altered into a hornblende
scapolite rock. The principal associated minerals are quartz,
mica, tourmaline, scapolite, feldspars, rutile, and magnetic and
titanic iron and sulphides of iron and copper. The country rock
is gneiss, schist, and granite. The mineral belongs to the variety
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376 THE NON'METALUC M.NER^IS.
called fluor-apatite, as shown by the following analysis from Dr.
Penrose's Bulletin:
APATITS FROM AUNDAI„
CouUturau.
PwCanl.
41. Jig
3.4'S
■00.00.
The Norway apatites have been mined according to Penrose
^ce 1854, the earliest workings being at Kragerd. According to
Davies, however, the discovery of deposits that could be profitably
worked dates only from 1871. The distribution of the, material
is very uncertain and irregular, and the value of the deposits can
not be foretold with any great approximation to accuracy. A
lai^e mass of this material, weighing nearly 2 tons, is on exhibition
in the National Museum at Washington.
Spain. — Important deposits of phosphorites occur between
Logrosan and CAceres, in Estremadura Province. The deposits are
in the form of pockets and veins in slates and schists supposed to
be of Silurian age; at times a vein is found at the line of contact
between the slate and granite. The veins vary in thickness from i
to several feet, the largest being some 20 feet and extending for over
2 miles. This is by far the largest of its kind known. As described,
the Logrosan phosphate has a subcrystalline structure; sometimes
fibrous and radiating. It is soft and chalky to the touch, easily
broken, but difficult to grind into a fine powder. An examination
under the microscope exhibits conchoidal figures, interrupted with
spherical grains, devoid of color and opaque.
The highest-grade material is rosy white or yellowish white
in color, soft, concentric, often brilliantly radiated, with a mam-
' Equal 91.1S9 per cent tricalck phosphate.
' Equal 7.01 per cent fluoride of calcium.
' Equal 0.801 per cent chloride of calcium.
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PHOSPHATES.
277
miliary or conchoidal surface. Red spots from iron and beautiful
dendrites of manganese are not infrequent. The poorer qualities
are milky white, vitreous, hard, and, though free from limestone,
contain considerable silica.
In the Cficeres district the phosphorites occur not in veins, but
rather in pockety masses in veins of quartz and dark-colored lime-
stone, which are found cutting both the granite and slate.
The following analyses from Dr. Penrose's paper show about the
tiverage composition of these phosphorites:
c™a„„».
Pet Cent.
1.70
CAOSRES.
PerCcnl.
Insoluble siliceous matter
Water expelled at a red heat ... .
a 1. 05
3.00
71.10
3.8s
Portugal. — Phosphorites occur in Silurian and Devonian rocks
under similar conditbns to those of Spain in Estremadura, Alemetjo,
and Eeira provinces, and which need, therefore, no further notice
here. Stanier,' however, describes a variety found in pockety and
short veinlike masses whkh are worthy of a passing notice. These
occur not m schists and sedimentary rocks but in massive granites.
They are found mainly in the superficial portions, where the granite
has weathered away to a coarse sand, and in short gash-like veins
and pockets of slight width and extent The phosphatic material
is described as of a milk-white color, opaque, and showing when
' Lcs Phosphorites du Portugal, Anoalcfi de la Soci^j Gfologique de Belglque,
XVII, 1890, p. 313.
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378 THE NON-METALUC MINERALS.
broken op«i a palmately radiating structure, like hoarfrost upcm
a window pane. As a rule the masses when found are enveloped
in a thin coating of kaolin-like material supposed to be derived
by decomposition from the feldspar of the granites. They are
mined only from open cuts and in the suf>CTficial more or less de-
composed portions of the rock, to which they are believed to be
mainly limited, having originated, as elsewhere indicated, through
a segregation of the phosphatic material dissolved by meteoric
waters from the surrounding granite and subsequently depositing
it in pre-existing fissures. The percentage of tricakic phosphate is
giv^i as varying between 60 and 80 per cent
(2) Rock Phosphates.
Untied States. — Nodular phosphatic deposits are found at inter-
vals all along the Atlantic coast of the United States, from North
Carolina down to the southern extremity of Florida, The North
Carolina deposits occur principally in the counties of Sampson,
Duplin, Pender, Onslow, Columbus, and New ^anover, all in the
southeastern part of the State. The deposits are of two kinds: (i) a
nodular form overlying the Eocene marls and consistii^ of phos-
phate nodules, sharks' teeth, and bones embedded in a sandy or
marly matrix, and (2) as a conglomerate of phosphate pebbles, sharks'
teeth, bones, and quartz pebbles, all well rounded and cemented
together along with grains of greensand in a calcareous matrix.
The beds of the first variety usually overlie strata of shell marl,
though this is sometimes replaced by a pale green indurated sand.
The two following sections will serve to illustrate their mode of
occurrence :
NTY, svnJN comm.
(0 Boil, sand, or clay, 5 to lo feet. (i) Sandy toB, i to 10 feeL
(a) SheU inari, s to 10 feet. CO Nodule bed, i to a feet.
(3) Bed with phosphate nodutes, I to 3 (3) Shell mad.
feet.
(4) Sea-green iandy marl, a to 4 feet.
(5) Ferruginous hardpan, 6 to 12 inchta.
(6) IntcTslratified lignites and sands u
in U)-
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PLATE XXVI.
Map o( ihe Florida Phosphate Regions.
[A/ler G. H. Eldridge, U. S. Geological Survey.]
[Facing page 278.]
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PHOSPHATES. 379
The nodules are of a lead-gray color, varying in size from that
of a man's fist to masses weighing several hundred pounds. In
texture they vary from dose, compact and homogeneous masses to
coarse-grained and highly siUceous rocks distinguished by con-
siderable quantities of sand and quartz pebbles sometimes the size of
a chestnut. Occasionally the nodules, which as a rule are of an
oval flattened form, contain Tertiary shells. The second or con-
glomerate variety occurs mainly in New Hanover and Pender
counties, the beds in some instances being 6 feet in thickness, though
usually much less. The following section, taken from Dr. Penrose's
Bulletin, shows their position and association as displayed at Castle
Hayne, New Hanover County.
"(i) White sand, o to 3 feet.
" (a) Brown and red ferruginous sandy clay, or clayey sand, i
to 3 feet.
"(3) Green clay, 6 to 12 inches.
"{4) Dark -brown indurated peat, 3 to 12 inches.
"(5) White calcareous marl, o to 2 feet.
"(6) White shell rock, o to 14 inches.
"(7) Phosphatic conglomerate, 1 to 3 feet.
"(8) Gray marl containing smaller nodules than the oveiiying
beds, 2J to 4J feet.
"(9) Light-colored, calcareous marl, containing nodules which
are smaller than those in the overlying beds, which grow fewer and
smaller at a depth. Many shells."
The phosphatic nodules in this conglomerate are kidney and e^
shaped and sometimes make up as much as three-fourths the contents
of a bed; usually, however, the proportion is smaller, and sometimes
there are none at aU. The mass as a whole does not contain more
than 10 to 20 per cent phosphate of hme, but it is said to have been
successfully used as a fertihzer. The individual nodules may be richer
in phosphatic matter on the outer surface than toward the center.
Aside from the phosphatic layer as described above, phosphatic
nodules are found in large quantities in the beds of rivers of these
districts, where they have accumulated through the washing action
of flowii^ water, the finer sand, clay, and gravel having been carried
away.. Such phosphates naturally do not differ materially from
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a8o THE NON-METALLIC MINERALS.
those on land except that they are darker in color and sometimes
more siliceous.
The deposits of South Carolina are of the same nature as those
described above but of low grade. For many years they were more
generally used than any other American phosphate. This was due
not only to the cheapness of the material but to the many good
qualities of the low-grade acid phosphate made from it. Of late
years the Florida phosphates have gradually replaced them.
Phosphates in the form of nodules and phosphatic marls and
green sands occur in Alabama in both the Tertiary and Cretaceous
formations. Their geographical distribution is therefore limited
to areas south of the outcrops of the lowest Cretaceous beds which
stretch in a curve from the northwest comer of the State across
near Fayette Courthouse, Tuscaloosa, Centerville, and Wetumpka,
to Columbus, Georgia, As all the Cretaceous and Tertiary beds
have a dip toward the Gulf of from 25 to 40 feet to the mile, the
phosphate-bearing strata appear at the surface in a comparatively
narrow belt along the line above indicated and are to be found only
at gradually increasing depths below at points to the southward.
Although selected nodules may run as high as 27 per cent of
phosphoric acid, and marls as high as 6.7 per cent, the Tertiary
is not regarded by Professor Smith as a promising source of com-
mercial phosphates in the State.
The principal phosphate region of Florida, as known to-day,
comprises an area extending from west of the Apalachicola River
eastward and southward to nearly 50 miles south of Caloosahatchee
River, as shown on the accompanying map.' According to Mr.
Eldridge, the deposits comprise four distinct and widely different
classes of commercial phosphates, each having a peculiar genesis,
a peculiar form of deposit, and chemical and physical properties
such as readily distinguish it from any of the others.
According to their predominant characteristics or modes of occur-
rence, these classes have come to be known as hard-rock phosphates,
soft phosphate, land pebble or matrix rock, and river pebble. With
the exception of the soft phosphates, they underlie distinct regions,
I Prelimiiur; sketch of Phosphates of Florida, by George H. Eklridge.
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PHOSPHATES. a8i
each class being separate or but slightly commingling with one
another. The hard-rock phosphate is a hard, massive, close-
textured, homogeneous, light-gray rock, showing laige and small
irregular cavities, which are usually lined with secondary mam-
millary incrustations of nearly pure phosphorite.
The deposits, which average some 36.65 per cent P,0(, lie in
Eocene and Miocene strata, occurring in the first named as a bowlder
deposit in a soft matrix of phosphatic sands, clays, and other material,
resulting from the disintegration of the hard rock and constituting
the soft phosphates. They underlie sands of from 10 to 20 feet in
thickness, and have been penetrated to a depth of 60 feet. The
phosphate deposit proper is white, the bowlders of roimded and
irregular outline, varying in diameter from 2 or 3 inches to 10 feet.
None of the hard-rock deposits of the Eocene originated in the
positions they now occupy. The Miocene hard-rock phosphates,
on the other hand, lie in regular bedded deposits in situ, as well as
in bowlders. The beds lie horizontal but a few feet below the sur-
face, being covered only by superficial sand. They are, as a rule,
but from 4 feet to 5 feet thick. The name soft rock, or soft phos-
phate, as above indicated, is given to the softer material associated
with the hard rock, which in part results from the disintegration
of the last named. It is also applied somewhat loosely to any
variety not distinctly hard. It varies greatly in color, chemical and
physical characteristics, and rarely carries more than 30 to 25 per
cent of P30s-
The name land-pebble phosphate includes pebbles from deposits
consisting of either earthy material carrying fossil remains, grains
of quartz, and pisolitic grains of lime phosphate, or of a material
resembling in texture and other characteristics the hard-rock phos-
phate. The individual pebbles vary in size up to that of the English
walnut, are normally white, but when subjected to percolating water
become dark gray or nearly black. The exteriors are quite smooth
and glossy; such yield on an average some 30 to 35 per cent PjOj.
The river-pebble varieties differ from the last mainly in mode
of occurrence, being found, as the name would indicate, in the beds
of streams, where presumably they have accumulated through the
washing away of finer and lighter materials. They are most abun-
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282 THE NON-METALLIC MINERALS.
dant in the Peace, Caloosahatchee, Alafia, and other rivers entering
the Gulf south of Tampa and Hillsborough bays, though the Withla-
coochee, Aucilla, and rivers of the western part of the State, carry
also a mixture of pebbles, hard-rock fragments, and bones derived
from the various strata through which they have cut their channels.
The pebbles of the Western rivers show a very uniform composition,
and range from 25 to 30 per cent phosphoric anhydride CPjOj), or
about 65 per cent of phosphate of lime, the impurities being mainly
siUceous matter, carbonate of Ume, alumina, and iron oxides.
Phosphatic deposits of high grade and covering considerable
areas in western middle Tennessee were discovered during the
latter part of 1893. Since then development has been rapid, and
the State now stands second in rank, as a producer, being exceeded
only by Florida. The general distribution of the beds is shown
in the accompanying sketch map (Fig. 42), while their varying
thickness is shown in the columnar sections on PI. XXVII. The
essential facts regarding these deposits have been sunmiarized by
C W. Hayes ' from whose reports a large part of the material here
given is compiled. The deposits axe classified as —
I. Black phosphate (an original deposit).
1. Nodular.
2. Bedded, including odlitic, compact conglomeratic, and
shaly varieties.
n. White phosphate (a secondary deposit).
1. Stony.
2. Breccia.
3. Lamellar.
The first of these, the black phosphate, is of Devonian age.
The second, the white phosphates, which are altogether secondary
deposits, are very recent. The surface rocks of the region include
Silurian, Devonian, and Carboniferous beds arranged as follows:
Carboniferoul Cberty.shsly limestone.
r D Grcensand with phosphatic nodules.. &-t4 inchei
I C Carbonaceous black shale 0-6 feet
^*™"»" 1 B Bedded phosphate 0-40 inchea
[a Gray saadstoite 0-6 feet
Silurian. Blue limestone
' See i6tb, i;th, and 3ist Annual Reports, U. S. Geological Survey.
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PLATK XXVII.
Sections through the Tennessee Phosphate Beds.
[AfterC. W. Hayes, U. S. Geological Survey.]
[yacing page 3&a.1
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J, Google
PHOSPHytTES.
Fig. 41. — Map of Tennessee phosphate region.
[After C, W. Hayes, 17U1 Ann. Rep. U. S. Geological Survey.J
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a84 THE NON-METALUC MINERALS.
The black nodular phosphate occurs in a bLlck shale, in spher-
ical to broadly oval and flattened ellipsoidal forms, with smooth
surfaces and black color. They are easily detached from the matrix
and weather down rapidly to a gray, at times almost white, sand.
Their distribution is extremely irregular and they have not yet been
found in sufficient abundance to be profitably mined, although
individual nodules may contain from 60 to 70 per cent phosphate of
lime.
The black bedded phosphate lies immediately beneath the
black shale containing the phosphate nodules just noted and over-
lying a compact Silurian limestone. It is evident that it represents
a residual accumulation of the less soluble portions of preexisting
limestones which has been rearranged and strati&ed during a sub-
sequent period of depression of the land, and fmally covered by
the sediments now forming the black shale. The beds lie nearly
horizontally and are now exposed only where creeks have cut through
in the ordinary processes of erosion. As noted above, it occurs in
several varieties. The oolitic form has in the weathered outcrop the
appearance of a rusty porous sandstone. A close inspection of the
imweathered rock shows it to be made up of rounded or flattened
ovules of a blue-black color and small fossil shells or casts of shells
embedded in a fine-grained or structureless matrix which, like the
ovules, is composed mainly of phosphatic material made dark by
carbonaceous matter.
The compact phosphate variety resembles a fine-grained car-
bonaceous sandstone. When fresh it is of a dark gray to bluish-
black color, but weathers to a buff or dull yellow color, natural
joint blocks when broken across often showing a nearly black nucleal
portion surrounded by concentric shells of oxidized material of
varying shades of brown or yellow. Under the microscope this
variety is seen to be made up of small ovules and fossil casts closely
packed together without the amorphous matrix noted in the oSlitic
variety.
Closely associated with the above forms is the conglomeratic
variety consisting of beds of coaisc sandstone and conglomerate
containing varying amounts of phosphate. These are black in color
and weather brownish, also. The truly phosphatic portion of this
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PHOSPHATES. 285
variety resembles that of the compact and o6litic forms, but
it differs in the presence of varying amounts of quartz sand and
pebbles.
These three varieties of the black bedded phosphate are stated
to yield on the average some 70 per cent of phosphate of lime.'
The shaly variety is poorer in phosphoric acid and has the appearance
of a dark gray to black shaly sandstone. The distribution of the
black and blue-black phosphate is limited mainly to Hickman,
Lewis, and Perry coimties, the beds varying in thickness from o to
48 inches.
The white phosphates are associated with Carboniferous rocks,
though the formation of the phosphate itself is much more recent.
The stony variety, as it b called above, is a finely granular gray
rock- sometimes resembling a quartzitic sandstone, which occurs
in more or less regular bands alternating with thinner bands of
chert in a dark shaly siliceous limestone. Thin sections, under the
microscope, show a ground mass of chalcedonic silica inclosing
numerous very minute isotropic forms with the rhombic outlines of
calcite but which chemical tests show to be phosphate. This variety
yields from 27 to 33 per cent phosphate of lime, Ca3(P0^2. The
breccia phosphate occurs in irregular masses composed of small,
angular fragments of the chert embedded in a matrix of the lime
phosphate, the chert fragments varying in diameter from a fraction
of an inch to 3 or 4 inches. The lamellar variety consists, as the
name suggests, of thin parallel plates or layers, sometimes several
inches in width of phosphatic material.
The white phosphate is limited in its distribution to an
area of about 12 square miles in the northern part of Perry
County.
In addition to the above Hayes has described ^ a brown residual
phosphate occurring in the form of a " blanket " deposit (see Fig. 43),
iiiunediately underlying the suriace soil and overlying Silurian and
Devonian limestones, in Hickman, Williamson, Mauiy, and Lewis
' The author's invenigaiions led him to place the attage cotuiderably lower,
selected samples yiekUng but from JO to 66 per cent Caa(POJi.
' Columbia Folio, No. 95, U. S. Geological Suivey, 1903,
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a86 THE NON-MET^LUC MINERALS.
counties of the same State. The material plainly results from the
weathering of the surface rocks, the prevailing lime carbonate
being carried away in solution while the phosphatic and other less
soluble constituents remain. The amount of phosphate naturally
varies with the amount of leaching the beds have undergone and
their content of insoluble constituents. Thicknesses of 30 feet.
(6) Collar deposit formed on sI«P slope by lurface iMthLng of the lime«tone. Shows mlu
overplaced deposit covering the edcB of underlying nonphoaphalic limestone.
Fic. 43.— Sections showing mode of occurrence and formation of residual pbospbates
in Tennessee.
[After C. W. Haj-es, U. S. Geological Survey.]
carrying from 70 per cent to 80 per cent 01 phosphate of lime, are
reported,
Phosphatic limestones of Ordovician age have a wide geographic
distribution throughout northern Arkansas, and have been developed
on a commercial scale on Lafferty Creek, in the western part of
Independence County. The following section of the bed is given
by Purdue;'
' Bulletin No. 315; U. S. Geological Survey, 1906, p. 469.
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PHOSPHATES.
St. Clair Limestone.
Brawn and black shale a
Low-grade manganiferous iron o
Green lo dark clay shale o
High-giade phosphate 4} to 6
Manganiferous iron ore o
Low-grade phosphate 4
Polk Bayou limestone o
The upper bed phosphate only is worked, the lower being of
too poor grade. The better class of rock is described as light gray
in color, compact and homogeneous, though sometimes conglomer-
atic, the larger particles being at times a fourth of an inch in
diameter. It carries from 25 per cent to 32 per cent PaOs. The
phosphatic nature is ascribed to organic matter — shells, bones, and
the droppings of marine animals.
Within a few years certain portionj of strata of Carboniferous
rocks — mainly limestones — in northern Utah, southeastern Idaho,
and adjoining portions of Wyoming, and in northern Nevada, have
been found surprisingly rich in phosphate. The entire phosphatic
series, which in places is qo feet in thickness, consists of alternating
layers of black or brown phosphatic materials, shale, and hard blue
or gray compact limestone. The beds themselves vary from a few
inches to 10 feet in thickness, but in the latter cases, are usually
broken by lean, shaley layers. At the base, the series begins with
limestone, which is succeeded by 6 to 8 inches of soft brown shales.
Overlying this is the main phosphate bed, 5 to 6 feet in thickness.
This is oolitic in structure, and runs high in P2O5. Several other
beds, from a few inches to 10 feet in thickness, separated by thin
beds of limestone or shale, occur. The series is overlaid by a coarse-
grained, locally brecciated limestone, and above this again, white
limestone, red sandstone, and shales, and still again, other limestones
of blue-gray and greenish colors. Beneath are found red, whit^
and greenish quartzites and sandstones. The strata have all been
uplifted, and sharply folded and faulted. A typical section is shown
in Fig. 44. The material as thus far shipped runs a little over 31
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388 THE NON-METALLIC MINERALS.
per cent of PsOe, which is equivalent to 70 per cent of bone phos-
phate.*
Fic. 44. — Typical Section of Lower Portion of Phosphate Series, Montpelier, Idaho.
[U. S. Geological Survey.]
England. — Deposits of phosphates sufficiently concentrated for
commercial purposes lie near the upper limit of Cambro-Silurian
strata in North Wales. According to Davies, the material occurs
in the form of nodular concretions of a size varying from that of
an egg to a cocoanut, closely packed together and cemented by a
black slaty matrix. The concretions have often a black, highly
polished appearance, due to the presence of graphite, but owing to
' F. B. Weets, Bulletin No. 315, U. S. Geological Survey, 1906, p. 449.
ovGoo'^lc
PHOSPHATES. 389
the presence of oxidizing pyrite they sometimes become rusty brown.
The concretions carry from 60 to 69 per cent of phosphate of lime;
the matrbc is also phosphatic. The beds are highly tilted and are
overlaid by gray shales with fossilized echinoderms and underlaid
by dark crystalline limestone, which also contains from 15 to 20 per
cent of phosphatic material. Davies regards the deposit as repre-
senting an old sea bottom on which the phosphatic matter of crustacean
and molluscac life was precipitated and stored during a long period;
certain marine plants may also have contributed their share of phos-
phatic matter. He thinks it also possible that, as In the Laurentian
deposits, the water of the sea may have contain&d phosphatic matter
in solution to be deposited independently of organic agencies.
These phosphated beds have been mined at Berwin, where an
average production over a space of 360 fathoms was 2 tons 10
hundredweight of phosp':ate per fathom, of an average strength of
46 per csnt. The nodules avcr2ged from 45 to 55 per cent of phos-
phate of lime.
Amorphous nodular phosphates alsa occur in both the Upper
and Lower Greensands of the Cretaceous and in Tertiary deposits.
Those of the upper beds have been mined in Cambri(^eshire and
Bedfordshire. The phosphatic material occurs in the form of
shell casts, fossils, and nodules, of a black, or dark-brown color, of
varying hardness, embedded in a sand consisting of siliceous and
calcareous matter as well as phosphatic and glauconitic grains.
The average com[>osition shows from 40 to 50 per cent of phosphate
of lime. The thickness of the nodule-bearing bed is rarely over a
foot. The nodules of the Lower Greensands differ from those of
the Upper in many details, the more important being their lower
percent^es of phosphate of lime (from 40 to 50 per cent). They
occur in a bed of siliceous sand which itself is not phosphatic. The
Tertiary phosphates reach their best development in the county
of Suffolk, where they are found at the base of the Coralline and
Red Crag groups and immediately overiying the London clays.
The beds consist of a "mass of phosphatic nodules and shell casts,
siUceous pebbles, teeth of cetaceans and sharks, and many mammal
bones, besides occasional fr^ments of Lower Greensand chert,
granite, and chalk flints." The nodules vary in both quality and
quantity. They are at times of a compact and brittle nature, while
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apo THE NQN-MET^LLIC MlfiERMLS.
at Others they are tough and siliceous. They average about 53
per cent phosphate of lime and 13 per cent phosphate of iron.
France. — Phosphates of the nodular type occur in beds of Cre-
taceous age in the provinces of Ardennes and Meuse, and to a less
extent in others in Northern France; in the department of Cote-d'Or,
and along the Rhone at Bellegarde, Seyssel, and Grenoble. As
in England, the phosphatic nodules of the northern area, such as
are of commercial importance, occur in both the Upper and Lower
Greensands. They resemble in a general way the English phos-
phates, but are described as soft and porous and easily disintegrat-
ing when exposed to the air. Those of the Upper Greensand average
some 55 per cent of phosphate of lime.
More recently deposits have been described by M, J. Gosselet,*
near Fresnoy-le-Grand, in the north of France. The phosphatic
material occurs in a zone of gray chalk some 6 feet in thickness
(ij to 3 meters), and is in the form of concretionary nodules forming
a sort of conglomerate in the lower part of the bed. A portion
of the chalk is also phosphatic. Phosphatic material (of the type
of phosphorites) is found in fissures and packets in the upper portion
of limestones of Middle Jurassic (Oxfordian) age, in the depart-
ments of Tara-et-Garonne, Aveyron, and ZotL
The deposits are of two kinds. The first occurring in irregular
cavities or pockets never over a few yards long, and the second in
the form of elongated leads with the sides nearly vertical. These
are generally shallow, and thin out very rapidly at a short distance
below the surface.
The nodules or concretions are of a white or gray color, waxy
■ luster, and opal-like appearance, and occur in the form of tubercular
or kidney-shaped masses embedded in ferruginous clay in the clefts
of the limestone, or in geodic, fibrous, and radiating forms.
The material of this region is known commercially as Bordeaux
phosphate, being shipped mainly from Bordeaux. It aver^es from
70 to 75 per cent phosphate of lime, the impurities being mainly iron
oxides and siliceous matter.
1 Annates de i^ Socii.i Gfologique du Nord, XXI, '1395, p. 149.
J, Google
PHOSPHATES. agi
Gautier' describes deposits of phosphates estimated to the
amount of 120,000 to 300,000 tons on the floors of the Grotte de
Minerve, near the village of Mftierve on the northeast flank of the
Pyrenees, in Aude, France. The cave proper is in nummulitic
limestone of Eocene age, the floors being formed by Devonian
rocks. The filling material consists of cave earth and bone breccia
below which are the aggregates of concretionary phosphorites and
other phosphatic compounds of lime and alumina, the more in-
teresting being Brushite, a hydrous tribasic calcium phosphate
hitherto known only as a secondary incrustation on guano from the
West India Islands, and Minervite, a new species having the formula
AljOj,P,0„7H)0, a hydrous aluminum phosphate, existing in the
form of a white plastic clay-like mass filling a vein from a few inches
to 2 or more feet in thickness.
Germany. — According to Davies, the principal phosphate regions
of North Germany occupy an irregular area bounded on the noith-
east by the town of Weilburg, on the northwest by the Westerwald,
on the east by the Taunus Mountains, and on the south by the town
of Dietz. The material occurs in the form of irr^ular nodular
masses of all size; up to those of several tons weight, embedded
in day which rests upon Devonian limestone and is overlaid by
another stratum of clay. The phosphate-bearing day varies in
thickness from 6 inches to 10 feet. With the phosphate nodules
are not infrequently associated deposits of manganese and hematite.
Davies regards the deposits as of early Tertiary age. The color
of the freshly mined material varies from pale buff to dark brown,
varying in specific gravity from 1.9 to 2.8, the quality deteriorating
with the increase in gravity. Selected samples of the staple nodules
yielded as high as 92 per cent phosphate of lime; but the average
is much lowjr, being but about 50 to 60 per cent phosphate of
lime.
Belgium. — Nodular phosphate; belonging to the Upper Cre-
taceous formations occur in the province of Hainaut, where t'ey
form the basis of an extensive industry. The nodules which are
' Annates des Mines, V, p. 5.
J, Google
aga THE NON-MET^LUC MINERALS.
generally of a brown color and vary in size from the fraction of i to
4 or 5 inches in diameter, lie in a coarse-grained, friable rock called
the brown or gray chalk, which itself immediately underlies what is
known as the Ciply conglomerate. The phosphate-bearing bed is
sometimes nearly loo feet in thickness, but is richest in the upper
lo feet, where it is estimated the phosphatic pebbles constitute
some 75 per cent of its bulk. Below this the bed grows gradually
poorer, passing by gradations into the white chalk below.
The overlying conglomerate also carries phosphate nodules,
which carry from 35 to 50 per cent phosphate of lime. Owing
to the hardness of the inclosing rock they are less mined than those
in the beds beneath. The mining of phosphates is carried on ex-
tensively near the town of Mons, on the lands of the commimes of
Cuesmes, Ciply, Mcsvin, Nouvelles, Spiennes, Sl Symphorien, and
Hyon. The annual output has gradually increased from between
3,000 and 4,000 tons in 1887 to 85,000 tons in 1894. Other phos-
phatic deposits are described ' as occurring in the provinces of
Antwerp and Lifege.
Italy. — Phosphatic deposits consisting of coprolites, bones, etc,
embedded in a porous Tertiary limestone, occur between Gallipoli
and Otranto, Cape Leuca, west of the Gulf of Taranto, on the
Italian coast There are two beds ha^'ing a thickness of rgj and
3ii indies, respectively, and which have been traced for a distance
of some 160 yards. Analyses show them to be of low grade, rarely
carrying as high as 10 per cent PiOi-
Tunis. — Phosphatic nodules in the form of cylindrical coprolites
and clustered aggregates have been found in Tertiary strata covering
considerable areas in the region south of Tunis. The coprolite
luxlules are stated to cany as high as 70 per cent of calcium phos-
phate, and the clustered aggregate some 52 per cent.
Russia, — Rich phosphate deposits of Cretaceous age occur in the
governments of Smolensk, Orlow, Koursk, and Vorouez, between the
rivers Dnieper and the Don in European Russia. The de[>osits lie
mosdy in a sandy marl, underlying white chalk and overlying green-
'Annalesde laSuci^If G£okigique de Belgique, XVllI, 1S90, p. 18;.
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PHOSPHATES. 393
sands, which also carry beds of from 6 to 12 inches thickness of phos-
phatic nodules. The nodules are dark, often nearly black in color,
and are intermixed with gray, brown, and yellow sands. The depth
of the beds below the surface is variable. Yermolow ' divides the
deposits into two groups, the first presenting the form of separate
nodules, rounded or kidney-shaped, of variable size, and black,
brown, gray, or green in color. The second is in form of an agglom-
eration of large nodules cemented together into a sort of flag, which
used to be quarried for road purposes. The nodules in this ag-
glomerate are richer in phosphoric acid when most dense and of a
deep-black color, the sandy varieties being comparatively poor. TTie
cement carrying the nodules contains numerous fossil bones, shells,
corals, etc., which are also phosphatic. The samples yield about
30 to 60 per cent phosphate of lime. Other deposits occur south
of Saratov, on the Volga; at Tambov and Spask, where the overlying
rock is a greensand in place of the chalk; north of Moscow; east of
Nijni Novgorod; at Kiev, on the Dnieper; Kamenetz, Podolsk, on
the Dniester, and at Grodno, on the Niemen.
Maltese Islands} — Nodular phosphates occur in Miocene beds
on the islands of Malta, Gozo, and Comino, of the Maltese group
in the Mediterranean Sea. The bed containing the nodules is in
what is known as the Globigerina limestone, which underlies an
upper coralline limestone, greensands, and blue clays, and overlies
the lower coralline limestone. Upper and lower beds all carry
phosphoric acid in small amounts. There are four seams of nodules,
the first varying in different locaUties from 9 to 15 inches in thickness,
The second is more constant in character, averaging some 2 feet
in thickness and consisting of an aggregate of irregularly shaped
nodules, intermixed with which are considerable quantities of the
phosphatized remains of moUusks, coraUines, echinoderms, crus-
taceans, sharks, whales, etc., the whole being firmly bound together
by an interstitial cement, composed of foraminiferal and other
calcareous matter similar to that of which the overlying beds are
made up. The third seam is the poorest of the lot and consists
' Recherches sur les Gisements de Phosphate de Chaux Fossil en Rusaie.
' J. H. Cooke, The Phosphate Beds of the Maltese Islands. Engineering and Min-
ing Journal, LIV, iSgi, p. aoo.
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394
THE NON-METMLUC MINERALS.
of two or more thin layers of nodules, none of which exceeds 3 inches
in thickness. Between this and the fourth and lowest seam, which
is the most important of all, is a bed of rock some 50 to 80 feet in
thickness. The seam averages some 3} feet In thickness. The
nodules are of a dark-chocolate color embedded in a calcareous
matrix, from which they are freed by calcination. The composi-
tion of I, the nodules, and II, the average composition of nodules
and interstitial cement, is given below, from analyses by Drs. Murray
and Blake:
I.
II.
1.16
4714
38.34
Trace.
6.08
1,97
Si.ia
J1.66
60.87
99.80
100.00
Guano, soluble and leached.— The largest and best-known
deposits of unleached guanos are foimd on the mainland and small
islands oS the coasts of Peru and Bolivia, where abundant animal
life and lack of rainfall have contributed to their formation and
preservation. These deposits consist mainly of the evacuations
of sea fowl and marine animals, such as flamingoes, divers, pen-
guins, and sea lions. Mixed with them is naturally more or less
bone and animal matter furnished by the dead bodies of both birds
and mammals. The deposits vary indefinitely in extent and thick-
ness, but have attained in places a depth of upward of 100 feet
As a rule they are more compact beneath than at the surface, but
may be readily removed by pick and shovel. The first deposits to
be worked are stated to have been those of the Chincha Islands, off
the Peruvian coast. These were practically exhausted as eariy as
1872. Other islands which have been worked and completely
if not entirely stripped are those of Macabi, Guafiape, Ballestas,
Lobos, Foca, Fabellon de Pica, Tortuga, and Huanillos.
A mean of 21 analyses of Macabi Island guano, by Barral, as
quoted by Penrose,' showed:
• Bulletin No. 46 of the United States Geological Survey.
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PHOSPHATES.
Nitn^n '. 10,90
Phosphates 27 ,60
Potash 2 to 3
Other analyses are given in the following table:
White Guuio.
BoHvi«n.
Paloi.
^■iSS"*
70.J1 to si-ga
30^ " 14.38
14.36 " 1744
13.30" 10.95
33.00
3-38
48^60
32-45
S-9a
7.18
34.81
»7-37 to 34-50
1.34" 6.98
1.61" 846
0*8.00" 31.00
Total phosphates
IkitdePe-
of Cuba.
•S:."
Galapa-
'£S
Onnui" tte
6.16
0.3S
as
0.56" a.jfi
Containing nitn^en
Equivalent in ammonia. . .
Total phosphates
0.31
" 34S
4.19
■' 35-0O
60.30
CDDsideniblc quantities of phosphatei of Blumina and ths
Aside from on the islands, guano is found all along the coast of
the Chilean province of Tarapaca, from Cannarones Bay to the
mouth of the river Loa, there being scarcely a prominence or rock
on the shore that is entirely free from it. According to the Journal
of the Society of Chemical Industry,' the deposits have been known
from a very early date. The aborigines of the valleys and gullies
of Tarapaca, Mamina, Huatacondo, Camina, and Quisma were
acquainted with the fertilizing qualities of guano, and conveyed it
from the coast to their farms on the backs of llamas.
The southern beds vary so much in aspect and color that it
frequently requires an experienced eye to make them out. Many
of the deposits are covered with immense layers of sand, while
others are buried beneath a solid layer of coi^lomerate. Guano
is also frequently found in the fissures and gullies which descend
to the seashore. The richest and largest beds are at Pabellon de
Pica, Punta de Lobos, Huanillos, and Chipana.
' Volume VI, 1887, p. ai8.
ovGoo'^lc
39^
THE NON-METALUC MINERALS.
Aside from the localities above mentfoned, guano is found on the
islands Itschabo, Possession, Pamora, and Halifax, off the Namagua
coast of South Africa. The material is described as fonning a
grayish-brown powder, free from lai^e lumps, and possessing a
faint amraoniacal odor. It carries from 8 to 14 per cent of nitrc^n
and 8 to 12 per cent of phosphoric acid.*
The West India /s/awi5.— Phosphates belonging to the class of
leached guanos occur in considerable abundance on several of the
islands of the West Indies group, the principal locahties being
Sombrero, Navassa, Turk, St. Martin, Aruba, Curafao, OrchiUas,
Arenas, Roncador, Swan, Cat or Guanahani, Redonda, the Pedro
and Morant Keys, and the reefs of Los Monges and Aves in Mara-
caibo Gulf. These, as would naturally be expected from their
mode of origin, vary greatly, not merely in appearances, but in
chemical composition as well. That of Sombrero is described *
as occurring in two forms — one a granular, porous, and friable
mass of a white, pink, green, blue, or yellow color; the other as
a dense, massive, and homogeneous deposit of a white or yellow
color. Many bones occur. The phosphate carries from 70 to 75
per cent phosphate of hme. An analysis as given by Davies * is
as follows:
F SOUBSEKO PHOSPHATE.
Per Cat.
Moisture and water of combination
8.92
31.73
45.69
5-99
■■»-~
The Navassa phosphate is described by D'Invilliers ' as occurring
(i) in the form of a gray phosphate confined to the lower levels of
I Journal of the Society of Chemical Induatry, I, 1S81, p. 39.
* R. F. Penrose, Bulletin No. 46 of the U. S. Geological Society.
* D. C. Davies, Eanhy and Other Minerals, p. 178.
* Equal to tricalcic phosphate, 69.27 per cent.
* Equal to carbonate of lime, 13.61 per cent.
* Bulletin of the Geological Society of America, II, 1891, p. 75-89.
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PHOSPHATES,
397
the island, and (2) a red variety occupying the ovai flat of the in-
terior. The gray is the better variety, as shown by the analyses
below, though both are aluminous, and difficult of manipulation
on that account. Both varieties occur in cavities and fissures in
the surface of the hard gray, white, or blue limestone, of which the
island is mainly composed. These cavities or f>ockets are rarely
more than 4 or 5 yards wide on the surface, and frequently much
smaller, and of depths varying from 5 to 35 feet. The deposits,
so far as explored, are wholly superficial. Experimental shafts
sunk to a depth of 250 feet have failed to bring to light any deeper
lying beds.
Water at 100° C
Organic malter and trater of combination
Magnet
Sesquioxicle of iron and alumina
Potash and aoda
Phosphoric acid
Sulphuric acid
Chlorine
Carbonic acid
ToUl
PHOSPHATE.
PerCBEt.
14.223
99.779
1. 160
3-S»7
Dme ■.::;■.■::;:
ioa.020
J, Google
THE NON-METALUC MINERALS.
The Aniba phosphate is described as a hard, massive variety
of a white to dark-brown color. The underlying corals of
this island are sometimes found phosphatized. An analysis
given by Da vies is as follows:
ANALYSIS OP AKTBA PHOSPHATE.
Moisture
Wa.ler of combination
Phosphoric acid '
Lime
0>n>ot)ic acid *
OxlJe nt iron
Alumina
Sulphuric adJ
Insoluble siliceous matter,
Toul
The Pedro Keys, Redonda, and Alia Vela phosphates carry
larger percentages of alumina and iron oxides, necessitating special
methods of preparation.
Deposits of leached guano of considerable extent have existed
on several islands of the Polynesian Archipelago, in the Pacific
Ocean, the better known being those of Baker, Rowland, Jarvis,
Maiden, Birmie, Phcenix, and Enderbury islands. The deposits
are described * as varying from 6 inches to several feet in thickness,
of a whitish-brown or red color, pulverulent when dry, sometimes
in the form of fine powder and again in coarse grains. Though
closely compacted, the material can, as a rule, be readily removed by
pick and shovel. The purest varieties are those lying on the un-
altered coral limestones,' of which the blands are mainly composed.
Those lying upon gypsum have become contaminated with sulphate
of lime. In places the deposits are covered with a thm crust due
' Equal to tricalcic phosphate, 61.15 P^^ cei^-
* Equal to carbonate of lime, 5.3a per ceui.
* J. D. Hague, American Journal of Sciettce, XXXIV, 1863, [
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PHOSPHATES.
999
io the action of atmospheric agencies. On Jarvis Island a con-
siderable share of the deposit is covered by material of this crust-
like character. Such on analysis are found to contain less water
and a. corresponding higher percentage of lime and phosphoric
acid than the loosely compacted material, being, indeed, a neariy
pure phosphate of lime. The following analyses show the
general character of the guanos from Baker Island, No. I
being freshly deposited and consisting of the dung of the
frigate bird {Pelkanus aquUus). No. II is a light-colored variety
from a deep part of the deposit, and No. Ill dark guano from a
shallow part
c™u..„»
I.
11.
III.
0.78
^.36
21.27
4-44
8.50
43-74
a.S4
1.30
39-7°
243
4»-34
»-7S
1.24
40.14
3-3'
Carbonic acid, chkmne, and alkalies, uodetennined . .
,00.00
100.00
Bat Guano. — ^The diy atmosphere of caves preserves indefinitely
the fecal matter of bats and such other animals as may frequent
them. Such under favorable conditions may accumulate in suf-
ficient quantities to become of economic importance, being gathered
and used as a fertilizer under the name of bat guano. The usual
form of the entrances to caves is, however, such as to make the
process of removal tedious and expensive.
Bat guano is, as a rule, dark in color, of a glossy, almost muci-
laginous appearance, and quite hard. Its composition is shown
in the following analysis of a sample from the Wyandotte caves *
in southern Indiana:
' Geology of Indiana, 1878, p. 163.
ov Google
THE NON-METALLIC MINERALS.
CooiCiciunti.
PerCait.
Lossal red heal
k
9°
»S
"3
3°
95
77
SUka
Lime
Cbknide of alkalies and lou
100. oo
According to the reports of the State geologist, the caves in the
Silurian strata in Bumet County, Texas, are in many instances
enormously rich in bat guano,
Muntz and Marcano ' have called attention to the extensive
deposits of guan0, sometimes amounting to millions of tons, in
caves in Venezuela and other parts of South America.
According to them the deposits consist not merely of the excreta
of the birds and bats which frequent the caves, but also of the dead
bodies of these and other animals. The excreta were found to
consist almost wholly of the remains of insects. Through the
agency of bacteria, nitrification takes place, whereby the organic
nitrogen is converted into nitric acid, which combines with the lime
from the bones or the carbonate of lime in the soils to form nitrates,
as described on "page 319,
Uses. — The phosphates of the classes thus far described are
used wholly for fertiUzer purposes. In their natural condition they
exist in the form known to chemists as tribasic phosphates — that
is, a compound in which three atoms of a base mineral, usually
calcium, are combined with one of phosphoric anhydride (P,OJ,
Thus the common tribasic phosphate of lime, or tricalcic phosphate
' Comptea Rendiii de I'Acad&nie des Sciences, Paris, 1SS5, p, 65,
J, Google
PHOSPHATES. 301
as it is more commonly termed, has, the formula Ca3(P04)2'=45.8i
parts by weight PaOs and 54.19, CaO. Other bases, as alumina,
iron, or magnesia, may partially replace the lime, but the phos-
phate is always deteriorated thereby. This is particularly the
case when aluminum and iron are the replacing constituents. Al-
though when finely ground the tricalcic phosphates are of possible
value for fertilizers, it is customary to first submit them to chemical
treatment in order to render them more readily soluble.
This treatment consists, as a rule, in converting them into a
superphosphate by sulphuric acid, whereby a portion of the bases
become converted into sulphates and the anhydrous and insoluble
tribasic phosphate into a hydrous and soluble monobasic form of
the formula CaO.(H20)2.P206. There are other reactions than
that above given, the discussion of which would be out of place
here, and the reader is referred to especial treatises on the subject
BIBUOGRAPHY.
K. A. F. Penrose, Jb. Nature and Or^in of Depoiiu of Phosphate of Lime. Bul-
telin No. 46, U. S. Geological Survey, iSSS. Gives a bibliography, up to date
of pubUcation. The folbwing have appeared dnce:
W. H. Adaus. List of Commercial Pbo^hatcs.
Trancactions of the Amerkan Institute of Mining Engineers, XVIII, 1869,
p. 649.
PAtn. Levy. Des phosphates de chaux. De leurs principaux gisements en France
et }k I'fttanger des gisements r^cemment d^couvcrtes. Utilisation en agriculture;
■wrftnihtinn par les plants.
Annates des Sciences Gtebgique, XX, 1S89, p. 78.
Theodok Delhak. Das Phosphoritlager von SCeinbach und allgemeine Gesichts-
punkte tlber Phosphorite.
Vierteljahrschrift dec Naturforschenden Gesellschaft in Zurich, i8go, p. i8a.
HZNu Lashe. Sur les Terrains phoqihates des environs de Doullens. Eiage S6k>-
nien ct Terrains superpose
Bulletin de la Soci^£ Gtelogiquede France, XVIII, 1890, p. 441.
Idem, XX, 189J, p. 311.
Idem, XXII, 1894, p. 345-
HjAUUK Lumdboeu. ApatitfOiekomster I Gellivare Ualmbeig ocb Kringliggande
Trakt.
Sveriges Geologisks UnderaOkning, aer. C, 1890, p. 48.
X. Stainier. Les depOis pho^bates des environs de Thuillies.
Annates de b SocUKi G&ilogique Belgique, XVII. 1890, p. LXVL
X. Stahoer. Les FbotphorjtM du Portugal.
Idem, p. 333.
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Soa THE NON-METALUC MINERALS. '
Edward V D'Invilliers. Pbo^bate Deposits o( the Island of NavHsaa.
Bulletin ot the Geologkal Society ot America, II, 1S91, p. 75,
N. De Mabcy. Remarques sur les Gttes de Phosphate dc Chaux de la Picardie.
Bulletin de b SociA^ Gfologique de France, XIX, 1S91, p. 854.
Eugene A. Smith. Pbo^hales and Marls of Alabama.
Bulletin No. 3, Geological Survey of Alabama, 1S91.
JOBN H. Cooke. The Phosphate Beds of (be Maltese Islands.
Engineering and Mining Journal, LIV, 189a, p. too.
D. C. DAVffis. Phosphate of Lime.
Chaps. VII, VlII, IX, X, pp. 109-iao, of A Treatise on Earthy and Other
Minerals and Mining, 3d ed., revised by E. Henry Daviea. London: Crosby,
Lockwood & Son, 1891.
HjALMAK LtiNDaoBU. AjMlilforekomster I Noirbottens Malmberg.
Sveriges Geologiska Unders6kung, ser. C, 1891, p. 38.
N. A. Pbatt. Florida Phosphates; The Origin of (he Boulder Phosphates of the
Withlacoochee River District.
Engineering and Mining Journal, LIII, 1891, p. 380.
Fbancis Wyait. Phosphates of America.
New York, 4th ed., 189a.
W. P. Blaee. Contribution to ibe Early Hiaiorv of the Industry of Phosphate of
Ume in the United States.
Transactions of the American Institute of Mining Engineers, XXI, 1S93. p, 157.
A. Gadtiek. Sur des phosphates en roche d'origine animale el sur un nouveau de
■ phosphorites.
Comptes Rendus, CXVI, 1893, pp. 918 and lou.
Sur la gen^se des phosphates naturels, et en particulier de ceux qui ont
emprunte leur phosphore aux £tres organises.
Comptes Rendus, CXVI, 1893, p. i>7[.
J. GOSSELET. Note sur les gltes du Phosphate de Chaux de Templeux-Bellicourt et
de Buire.
Socift* C&logique du Nottl, XXI, 1893, p. i.
, Note sur les glles de Phosphate de Chaux des environs de Fresnoy-le-Grand.
Idem, p. 149.
Geo, H. Eldridge. A Preliminary Sketch of the Phosphates of Florida.
Transactions of the Ameriisn Institute Mining Engineers, XXI, 1893, p. 196.
Charles Helson. Notes sur la nature et le gisement du phosphate de chaux naturel
dans les departments du Tam-et -Garonne et du Tarn.
Socift* G&li^que du Nord, XXI, 1893, p. 346.
Walter B. M. Davidson. Notes on the Geological Origin of Pi.osphate of Lime
in the United States and Canada.
Transactions of the American Institute Mining Engineers, XXI, 1S9J, p. 139.
William B. Pkillips. A List of Minerals containing at least one per cent of Phos-
phoric Acid.
Transactions of the American Institute Mining Engineer^ XXI, 1893, p. 188.
H. B. Small. The Phosphate Mines of Canada.
Transactions of the American Institute Mining Engineers, XXI, 1893, P* 774-
John Stewart. Lauientian Low-giade Phosphate Ores.
Traiuactioiis of the American Institute Mining Engineers, XXI, 1893, p. i7£>
ovGoo'^lc
PHOSPHATES 303
The Phoqibate Industry of the Uniied Stalei.
Sixth Special Report of the Commissioner of Labor, 1893. Washington: Gov-
ernment Printing Office.
M. Blayac Description G&logique de la Rigion des Phosphates du dyr et du
Kouif Piis TebJasa.
Annales dea Mines, VI, 1894, p. 319.
Note sur les Lambeaux Suesaoniens & Pbosptiate de Chaui de BordJ Redir
et du Djebel Mzeila.
Idem, p. 331.
Eugene A. Smth. The Phosphate* and Marls of the State.
Report on the Geology of the Coastal Plain of Alabama, 1894, pp. 449-535.
A. Gaut[£R. Sur un Gisement de Phoq)hates de Chaux et d'Alumine contenant des
eapices rares ou nouvelles et sur la Genise des PlKisphatea et Nitres nalurels.
Annates des Mines, V, 1894, p. 5.
Davu) Levat. ^lude sur I'industrie des Phosphates et Superphosphates.
Annates des Mines, VII, 1895, p. 135.
J. M. Safpord. Tennessee Phosphate Rocks.
Reportof the Commissioner of Agriculture, Nashville, Tennessee, 1S95, p. 16.
Chasles Willard Hayes. The Tennessee Phosphates.
Eitract from the Seventeenth ,\nnual Report of the U. S. Geological Survey,
1895-96. Pt. 2, Economic Geology and Hydrography. Washington: Govern-
ment Printing Office, 1896. Also Twenty-first Annual Report, . art III, 1899-
1900.
M. Badoxtseau. Sur les gisements de chaux phosphates de I'Estremadure.
Bulletin de la Soci^f Centrate Agriculture de France, XXXVIII.
X. Stainer. Bibliogrephie Gjn jrale des Gisements des Pho^hates.
Annates des Mines de Belgique, VII, 1901 el leq.
L. P. Brown. The Pho^hate Deposits of the Southern Stales.
Proceedings of the Engineering Association of the South. XV, No. 7, 1904,
pp. 53-"8.
F. B. Weeks. Bulletin No. 315. U. S. Geological Survey, 1906.
2. MONAZITE,
Composition, a phosphate of the cerium metals of the general
formula (Ce, La, Di) PO4. Actual analyses as given by Dana
yielded results as shown in table on page 304.
Hardness, 5 to 5.5; specific gravity, 4.9 to 5.3. Color, hyacinth-
red to brown and yellowish, subtransparent to translucent
Localities and mode of occurrence. — The common mode of oc-
currence of the mineral is that of minute crystals or crystalline
granules disseminated throughout the mass of gneissoid rocks.
Owing to their small size they have been very generally overlooked.
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THE N0N-MET/4LUC MINERALS.
Phosphoric anhydride {^fi^
Cerium sesquioridc {Ce,Oj
Lanthanum, scsquionde (LLOj) . .
DIdvmium BesquioiddF (Di,0,). ■■ .
Yttjium sesquiojtide (V Oj)
Iron sesquioxide (Fe,0,)
Silica CSiO,)
Tborta (ThO J
Lime<CaO) -
Ignition
J.8.
I. Burke County, North CatoUiM. II. Arendal. Norway.
and it is only where, through the decomposition of the inclosing
rock and the concentration of the monazite and the accompanying
heavy minerals — as magnetite, garnet, etc. — in the form of sand,
that it becomes sufficiently conspicuous to be evident. Prof. O. A.
Derby was the first to point out the widespread occurrence of the
mineral as a rock constituent, having obtained it in numerous and
hitherto unsuspected localities by washing the dftrb from decom-
posed gneisses of Brazil. Although widespread as a rock constituent
and of interest from a mineralogical and petrographical standpoint,
only the localities mentioned below have thus far yielded the mineral
in commercial quantities.
The Carolinas. — The mineral is found in commercial quantities
in the form of small brownish or yellow-brown water-worn granules
in stream beds and placer deposits of the Carolinas throughout the
area shown in the accompanying map (Fig. 45). The principal
producing areas include between 1,600 and 2,000 square miles in
Burke, McDowell, Rutherford, Cleveland, and Polk counties. North
Carolina, and the northern part of Spartanburg County, South
Carolina. The better deposits are found along the waters of Silver,
South Muddy, and North Muddy creeks, and Henry's and Jacob's
Forks of the Catawba River in DcMowell and Burke counties; the
Second Broad River in McDowell and Rutherford counties; and
the First Broad River in Rutherford and Cleveland counties, North
Carolina, and Spartanburg County, South Carolina. These streams
have their sources in the South Mountains, an eastern outlier of
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PHOSPHATES. 305
the Blue Ridge. Tbe country rock is granitic bk>tite gneiss and
dioritic hornblende gneiss, intersected nearly at right angles to the
schistosity by a parallel system of small auriferous quarts veins,
striking about N. 70° E. and dipping steeply to the N. W. The
thickness of the gravel deposits is from i to 2 feet, and the width of the
mountain streams in which they occur is seldom over 12 feet. Th?
percentage of monazite in the original sand varies from an infinites-
^^
^■:
^^1
I « 1 — s — *
Fig. 45- — Map of monazite areas in the CarDlinas.
[After J. H. Piatt, TmuBctioos of the American Institute of Mining Engineers.]
!mal quantity up to i or 2 per cent. The deposits are naturally
richer near the headwaters of the streams.
From these deposits amounts varying from 30,000 potmds to
if573i<}^o poimds have been washed annually since systematic
mining b^an in 1893. In 1901 the amount was 748,736 potmds,
valued at $59,262. The miner usually receives from 3i to 5 coits
per pound. Tlie existence of monazite in commercial quantities
in this region was first demonstrated by W. E, Hidden in 1879.
According to Lindgren ' munazite sand occurs in considerable
quantities in the r^ion known as the Id^o Basin, an area of some
' Eighteenth Annual Report U. S. Geological Survey, III, 189&-97, p. 677.
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3o6 THE NON-METALUC MINERALS.
150 square mQes about the headwaters of Moore Creek, in Boise
County, Idaho. The mineral is here associated witli ilmenite,
garnet, and zircon.
Brazil. — ^As above noted, the original source of the Brazilian
monazite were gneisses from which the mineral has been liberated
by decomposition. The particular localities examined by Professor
Derby are in the provinces of Minas Geraes, Rio de Janeiro, and
Sao Paulo. The most extensive accumulation thus far reported
is in the form of considerable patches on the sea beach near the
little town of Alcobaca in the southern part of the province of Bahia,
though it has been also found on other sea beaches and in river
sands. Nitze states: *
"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 nimiber of tons have
been shipped in the natural state, without any further concentra-
tion or treatment, as ballast, mainly to the European markets. It
is reported to contain 3 to 4 per cent thoria. . . . Monazite has
also been found in the gold and diamond placers of the provinces
of Bahia (Salabro and Caravellas), Minas Geraes (Diamantia),
Rio 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 Rio Chico, at Antioquia, in the United States of Colombia."
Russia, — "In the Ural Mountains of Russia monazite is found
in the Bakakui placers of the Sanarka River. The placer gold
mines of Siberia are reported to be rich in monazite, which is rafted,
down the Lena and the Yenesei rivers to the Arctic Ocean, and
thence to European ports.
Norway. — "Economic deposits of monazite are also reported
to exist in the pegmatic 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 i ton, which is shipped mainly to Germany.
Methods of extraction. — In the Carolinas the monazite is won by
■ Sixteenth Annual Report U. S. Geological Survey, 1S94-95, P'- 4i P- ^5-
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PHOSPHATES. 307
washing the sand and gravel in sluice boxes after the manner of
placer gold. Magnetite, and other ferriferous minerak, if present,
are eliminated from the dried sand by the electro-magnet. Many
of the heavy minerals, such as zircon, menaccanite, rutilc, brookite,
corundum, garnet, etc., can not be thus completely eliminated, and
the commercially prepared sand, therefore, is not pure monazite.
A cleaned sand containing from 65 to 70 per cent monazite has in
the past been considered of good quality, but of late years concen-
trating machines have been introduced by means of which sands
running as high as 80 per cent monazite are obtained.
3. TORBERNITE.
Composition: a hydrous phosphate of uranium and copper of
the general formula CuO, 2UO3, P2O8, 8H2O, which is equivalent
to uranium trioxide (UO3) 61.2 per cent, copper 8.4 per cent, phos-
phorous pentoxide (PaOs) iS-t per cent, water (HaO) 15.3 per cent.
Arsenic sometimes replaces, in part, the phosphorus. Color, green ;
when crystallized in the form of small square tablets, sometimes very
thin and foliated, in which form it has been called uranium mica.
The laminae are, however, brittle. The mineral has been found
in Cornwall, England, and in Saxony, Bohemia, and Belgium, but
in quantities of only mineralogical interest. What is reported is
a deposit of possible economic value has recently been discovered
in the Province of Guaida, in Portugal. Wm. Nivens also reports *
the finding of the material in a vein from 2 to 6 feet in width near the
Cerro Metafe, State of Guerrero, Mexico. Average samples are
reported to yield one-half of one per cent of uranium.
Uses. — The rare elements cerium, zirconium, thorium, yttriimi,
lanthanum, etc., which are as a rule associated with each other
in the minerals cerite, zircon, monazite, samarskite, etc., as de-
scribed, find their commercial use not in the form of metals, but
as oxides only; and it is only since the introduction of the Webbach
incandescent system of lighting that their use in this form has assumed
any commercial importance.
' The Mining World, Jan. 15, 1910
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3o8 THE NON-METALLIC MINERALS.
This Welsbach light consists of a cap or hood to gas or otHer
burners, to increase their illuminating powers. The cap is made
of cotton or other suitable material, impregnated with the oxides in
proportions 60 per cent zirconia, 20 per cent yttria, and 20 fwr cent
lanthanum. The fabric is strengthened and supported with fine
platinum wire and suspended in the flame. On igniting in the
flame the fabric is quickly reduced to ash, the cotton being burnt
away and the earthy matter still retaining the form of a cap or hood."
The drawback to the use of these oxides has been, it is said,^
the great difficulty in obtaining them in a pure condition. Several
methods have been used, but usually with poor results, especially
when the mineral contains iron. The cerium oxalate is used in
pharmacy.
The demand for the minerals of this group being so limited,
there is no r^ular market price. The Mineral Industry for rS93
quotes zircon at 10 cents a poimd, monazite, 25 cents, and samarskite,
50 cents. In 1901 monazite from North Carolina was quoted at
8 CQits per poimd, of which the original miners received from 3^ cents
to 5 cents per pound, according to the purity of the material. The
total output of the United States for 190S was 422,646 pounds,
valued at $50,718, or 12 cents per pound. It is stated that i ton of
zircon will yield sufficient zirconia for half a million Welsbach
burners. For uses of torbenite see under Uranates, p. 330.
BIBLIOGRAPHY.
See paper on Mon^te, by H. B. C. Nitie, in Miueisl Resources of the United
States, Fart 4> o( the Sixteenth Annual Report U. S. Geobgical Survey, 1894-95,
pp. 667-693. Thb contains a very saiiȣactory bibliography down to date of publi-
cation. Also aee Lea Terres Rarea Minerak^ie-Properties Analyse, by P. Trucbot.
Carri et Naud. Paris, 1S9S. Introduction to the Rare Elements, by P. E. Browning.
Wiky & Sons. New York, 1903.
4. WAVEIJ-ITE.
Wavellite. — ^Tliis mineral is a hydrous phosphate of alumina
corresponding to the formula 3AI2O32P2OB, 12H2O, The theoreti-
cally pure mineral would therefore carry some 15.37 P^ ^^^^ °^
' Journal of the Society of Chemical Industry, V, 1886, p. 51a.
• Mineral Resources of the United Stales, 1885, p. 393.
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PHOSPHATES. 309
phosphorus. Commonly 'n globular, botryoidal, and staladtic fonns
showing internally a findy fibrous, radiate structure; rarely in
distinct crystals; colors, white, yellowish, brown, or rarely greenish
or black. Hardness, 3.25 to 4; streak white; specific gravity, 2.33.
Occurrence and origin. — ^The common form of occurrence is as a
secondary mineral in residual clays and soils though also found in
rifts and pockets of still firm rocks associated with amblygonite and
other phosphates. It is fairly common as a mineral, but rarely
occurs in sufficient abundance to be of commercial value. At the
foot of the northern slope of South Mountain, in the vicinity of
Holly Springs, Pennsylvania, the mineral is found in quantity,
together with manganese ores and limonite in the surface sands,
gravels, and clays, which cover the rock outcrops, and which were
themselves derived from the neighboring sandstones, limestones,
and hydro-mica slates. It seems reasonable to conclude, according
to G. W. Stose • that the original deposition of the iron (limonite)
together with the wavellite, was in someway a feature of the change
of sedimentation from shore detritus to calcareous silt, probably
not as a massive bed of ore but as ferruginous sediments. The
phosphorus was probably associated with the iron in its original
occurrence and in the process of redeposition it combined with the
alumina, but it is possible that a part of the phosphorus may have
been derived from the remains of invertd)rate animals, trilobites
and other fossils being found in the limestones.
Hie wavellite, in form of nodular, disconnected masses is fotmd
scattered through a white clay and is mined by open cuts. The
output is used in the manufacture of phosphorus which, in its turn
is consumed mainly in the manufacture of matches.
5. AHBLYGOTfTTE.'
This is a fluo-i^osphate of aluminum and lithium of the formula
Li(AiF)P04. Anal3rsi5 of a sample from Paris, Maine, as given
by Dana, shows: Phosphoric acid, 48.31 per cent; aliunina, 33.63
per cent; Uthia, 9.82 per cent; soda, 0.34 per cent; potash, 0.08
' BoUetiD No. 315, U. S. Geological Survey, 1907, p. 477.
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THE NON-METALLIC MINERALS.
per cent; water, 4.89 per cent; Suorine, 4.82 per c&A. Hardness,
6; specific gravity, 3.01 to 3.09. Luster vitreous to greasy, color
white to pale greenish, bluish, yellowish, to brownish; streak white.
On casual inspection the mineral somewhat resembles potash feld-
spar (orthoclase), but when finely pulverized is soluble in sulphuric
acid, and less readily so in hydrochloric acid. Before the blowpipe
the mineral gives the characteristic lithia red color to the flame.
Mode of occurrence. — Amblygonite occurs in the form of coarse
crystals, or compact and columnar forms in pegmatic dikes asso-
ciated with lepidolite, tourmaline, and other minerals so charac-
teristic of this class of rocks. In the United States it occurs at
Hebron; Mount Mica, in Paris; Auburn and Peru, Maine, at the
last-named place associated with spodumene, petalite, and lepidolite.
In Saxony the mineral is found at Chursdorf wid Amsdorf, near
Penig, and near Geier, Also found at Arendal, Norway, and at
Montebras and Creuze, France,
Uses. — Since 1886 the mineral has been utilized as a source of
lithia salts, in place of the lithia mica. The chief commercial
source is at presoit Montebras, France, where it occurs in a coarse
granitic vein yielding also cassiterite and kaolin in commercial
quantities. (See also Spodumene, p. 200,)
6. TRIPHVLITE AND LTTHrOPHILITE,
These are names given to phosphates of iron, manganese, and
lithium, and which pass into one another by insensible gradations
through variations in the proportional amounts of manganese pro-
toxide, the triphylite containing from ly to 20 per cent of this oxide,
while the lithiophilite contains twice that amount. The compara-
tive composition of extreme types is shown below:
Name.
P^t.
F^.
MnO.
Li^.
NmO.
H.0
43..8
44-67
36.1.
4.0.
8.06
40.S6
\i\
0.16
0.14
0.87
oJi
Lithiophilite
Triphylite is a gmy to blue-gray mineral in crystals and coarsely
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FANADATES. 311
cleavable masses of a hardness of 4.5 to 5 of Dana's scale, and
specific gravity of 3.42 to 3.56.
Lithiophilite differs mainly in color — aside from composition
as above noted — being of a pink to dove-brown hue. Both minerals
may undergo a darkening in color, becoming almost black through a
higher oxidation and hydration of the manganese protoxide. This
feature is best shown in the hthiophilite from Branchville, Con-
necticut.
Occurrence. — These minerals occur chiefly in granitic veins,
associated with spodumene and other lithia-bearing minerals, as
at the localities above mentioned. Peru, Hebron, and Norway,
Maine, Keityo, Finland, etc. They have as yet been put to no
practical use.
7. VANADINITE.
This is a vanadinate and chloride of lead of the formula (PbCl)
PbiVaO 12 =- vanadium pentoxide, 19.4 per cent; lead protoxide,
78.7 per cent; chlorine, 2.5, In nature often more or less impure
through the presence of arsenic and traces of iron, manganese,
zinc, and lime. Color deep red to brown and straw-yellow, resinous
luster; translucent to opaque. Hardness, 2.75 to 3. Gravity,
6,66 to 7.23, When a drop of nitric acid is applied to a particle
of a crystal there b soon formed a yellow coating of vanadic oxide.
This reactbn is quite characteristic and furnishes an easy and
convenient means of determination.
Localities and mode of occurrence, — ^The mineral occurs in pris-
matic crystals with smooth faces and sharp edges; crystals sometimes
cavernous at the top. Also common in parallel grouped and rounded
forms and globular incrustations. Dana gives the following relative
to the known localities:
" This mineral was first discovered at Zimapan in Mexico, by
Del Rio. Later obtained among some of the old workings at Wan-
lockhead in Dumfriesshire, where it occurs in small globular masses
on calamine, and also in small hexagonal crystals; also at Berezov
in the Ural, with pyromorphite; and uear Kappel in Carinthia, in
crystals; at Undent, B6let, Sweden; in the Sierra de C6rdoba,
Argentine Republic; South Africa.
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312 THE NON-METALUC MINERALS.
" In the United States it occuiss paringly with wulfenite and pyro-
morphite as a coating on limestone, near Sing Sing, New York. In
Arizona it is found at the Hamburg, Melissa,
and other mines in Yuma County , in brilliant
deep-red crystals; Vulture, Phoenix, and
other mines in Maricopa County; at the
Black Prince mine; also the Mammoth gold
mine, near Oracle, Pinal County, and in
brown barrel-shaped crystals in the Humbug
district, Yavapai County. In New Mexico
it is found at Lake Valley, Sierra County
(endlicbite); and the Mimbres mines near
Georgetown."
The characteristic mode of occurrence at the Mimbres mines,
above noted, is associated with descloizite in the form of small
hopper-shaped crystals and drusy or botiyoidal and globular masses
coating the sihceous residues of the limestone in the irregular cavities
with which the stone abounds. The color of these coatings varies
from beautiful ruby red to light ocherous yellow. The mineral is
here nearly always associated with descloizites as noted below.
Uses. — See under Descloizite.
8. DESCLOIZITE.
This is a vanadinate of lead and zinc of the formula 4{PbZn)0.
V,0(,H,0, = vanadium pentoidde, 22.7 per cent; lead protoxide,
55.4 per cent; zinc oxide, 19.7 per cent; water, 3.2 per cent. The
published analyses show also small amounts of arsenic, copper, iron,
manganese, and phosphorus. Color, red to brown; luster, greasy; no
cleavage ; fracture small conchoidal to imeven. Occurs in small pris-
matic or pyramidal crystals and in fibrous, mammillated or massive
forms. Often associated with and pseudomorphous after vanadinite.
Localities and mode 0} occurrence. — Dana gives the following
relative to occurrence:
"Occurs in smaU crystals, i to a millimeters thick, clustered
on a siliceous and ferruginous gangue from South America, at the
Venus Mine and other points in the Sierra de C6rdoba, Argentine
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VANADATES. 313
Republic, associated with acJcular green pyromorphite, vanadinite,
etc. At Kappel, in Carinthia, in small clove-brown rtiombic octa-
hedrons.
"Sparingly at the Wheatley Mine, Phoenixville, Pennsylvania,
as a thin crystalline crust on wulfenite, quartz, and a ferruginous
clay. Abundant at the Sierra Grande Mine, Lake Valley, Sierra
County, New Mexico, in red to neariy black crystals, pyramidal
and prismatic in habit, associated with vanadinite, iodryite, etc.;
at the Mimbres and other mines, near Georgetown, New Mexico,
in stalactitic crystalline aggregates. In Arizona near Tombstone,
in Yavapai County, in brownish olive-green crystals; at the Mam-
moth Gold Mine, near Oracle, Pinal County, in orange-red to
brownish red crystals with vanadinite and wulfenite."
A vanadinite, probably identical with desdoizite, occurs at the
Mayflower Mine, Bald Mountain district, in Beaverhead County,
Montana; it is in an impure earthy form of a dull yellow to pale
orange color. (See further under Camotite, p. 332.)
Vanadium is also foimd in small quantities in certain Swedish
iron ores; in the cupriferous schists of Mansfeld, Saxony; in cupri-
ferous sands of Cheshire, England, and Perm, Russia; in coals
from various localities; in beaiudte and in clay near Paris. As
stated by Fuchs and De Launay,' vanadium has been shown to
exist in extremely small proportions in primordial rocks, from
which it became concentrated in the clays on their breaking up.
Certain oftiitic iron ores (limonites) at Mafenay, Sa6ne et Loire,
France, contain the substance in such proportions that the slags
from their smelting have become commercial sources of supply.
The following referring to the occurrence and value of vanadinates
in the United States is of suflkient interest to bear reproduction
here:
The lead vanadates are frequ»itly found in association with
lead ores, as, for instance, in the defKJsits at Leadville, whence
some very handsome specimens were formerly obtained. The
most important occurrence of lead vanadates in the United States,
however, is probably in Arizona, where it has been reported in the
' Trait* dra Giles Miii&»ux, II, p. 95.
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314 THE NON-METALUC MINERALS.
ores of several mines, among others those of the Castle Dome district,
■ the Crowned King mine in the Bradshaw Mountains, and the Mam-
moth gold mines at Mammoth, in Pinal County. The last-men-
tioned mines are probably the only ones in the United States from
which vanadiimi minerals have been won on an industrial scale.
The vanadium minerals, of which nearly all the known varieties
occurred, the dechenite and desdoizite predominating, were foimd
in the upper levels of the mine, forming about i per cent of the ore
on the aven^, thoi^h within Umited areas they fonned from 3 to
4 per cent. In the lower levek they occurred less abundantly,
only an occasional pocket and a small quantity of disseminated
crystals being found. The red crystals, according to an analysis
by the late Dr. F. A. Genth, contained chlorine, 243 per <%nt;
lead, 7.08 per cent; lead oxide, 69.98 per cent; ferric oxide, 0.48 per
cent; vanadic acid, 17.15 per cent; arsenic acid, 3.06 percent,
and phosphoric add, 0.39 per cent. In milling the ore (gold) the
vanadium mino'als collected in riffles. The total quantity of con-
centrates obtained in this manner did not exceed 6 tons. An average
sample of the tot, analyzed by Dr. Genth, gave the following results:
Vanadic acid, 15.40 per cent; molybdic acid, 3.35 per cent; arsenic
acid, 1,50 per cent; carbonic acid, 0.90 per cent; chlorine, 0.48 per
cent; oxide of lead, 56.80 per cent; oxide of zinc, 10.70 per cent;
oxide of copper, 0.95 per cent; oxide of iron, 0.35 per cent; soluble
silica, 0.60 per cent; insoluble matter, 5,29 pa cent The price
realized on this first lot was 13.5 cents per pound, or $250 per ton,
on board the cars at Tucson.
The vanadic salts manufactured from this lot of concentrates
were said to have been the first produced on a commercial scale
in the United States, and owing to the limited market for the same
the price dropped over 50 per cent (See also under Patronite,
p. 4r, and Roscoelite, p. 179.)
Uses. — The uses thus far developed for these minerals are as a
source for vanadium salts used as a pigment for poreelain and in
the manufacture of fenovanadium alloys to be used in steel-making.
Vanadate of ammonium and vanadic oxide are used in the manu-
facture of ink and in textile dyeing and printing, imparting intense
black colors with a slight greenish cast. Vanadium oxide obtained
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from the slags of the Creusot sted works in France is utilized as a
mordant in dyeing. When used in steel the vanadium is stated to
very gready increase the tensile strength and elastic limit A larger
supply, it is thought, would result in its use in armor plate, pro-
jectiles, and bronzes.
IX. NITRATES.
There are three compounds of nitric add and a base occurring
in nature in such quantities and of sufficient economic importance to
merit attention here. These are (i) the true niter or potassium
nitrate (KNO,), (2) soda niter or sodium nitrate (NaNO,), and
(3) nitrocalcite, a calcium nitrate (CaN,0,). All are readily soluble
in water, and hence found in any quantity only in arid r^ons or
where protected, as in the dry parts of caves.
I. NITEB, POTASSTOM NITRATE.
Composition. — KNO», = nitric anhydride (NO,)j 53-5 per cent;
potash (KjO), 46.5 per cent. Hardness, 2; specific gravity, 2.1;
color, white, subtransparent. Readily soluble in water. Taste,
saline and cooling. Deflagrates vividly when thrown on burning
coals and colors the fiame violet.
The mineral occurs in nature mainly in the form of adcular
crystals and efflorescences on the surface or walls of rocks and
scattered in the loose soil of Hmestone caves and similar dry and
protected places.
It is also found in certain soils of tropical countries, as noted
later under origin {p. 319). In the United States it has been found
in caves of the Southern States, as those of Madison County, Ken-
tucky, but never as yet in commercial qualides. The chief com-
mercial source of the salts has been the artificial nitraries of France,
Germany, Sweden, and other European countries. It is also pre-
pared artificially from soda niter.
2. SODA triTER.
Nitrate of sodium, NaNo3, = nitric anhydride (NOj), 63.5 per
cent; soda (NajO), 36.5 per cent This in its pure state is a white or
colorless salt, but in nature often brown or bright lemon-yellow, rf a
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3i6 THE NON-METALLIC MINERALS.
slight saline taste, but with a peculiar cooling sensation when placed
upon the tongue. It is by far the most common of the nitrates,
and IndeeH the only one of the natural salts of any great commercial
value, owing to the comparative rarity of the others. Though
found to a slight extent in caves and protected places, the commercial
supply is drawn almost wholly from the arid or pampas regbns of the
Pacific coast of South America and particularly from Chile, the chief
deposits being found in the provinces of Tarapaca and Antofagasta.
According to Prairose ' the pampas region has a general slo[>e
from east to west. .\s a result the western border, where is abuts
against the foothills of the coast range, is the lowest, and it is along
this zone that the nitrate deposits occur, occupying in Tarapaca
province a narrow north and south belt for a distance of over loo
miles. The beds are all supn-ficial deposits, from several to many
feet in thickness, and often capped by several feet of earthy material.
Most of the deposits, it should be noted, consist largdy of sodium
chloride (common salt), or a mixture of this salt and the niter.
Rarely does the crude salt carry over 70 per cent of niter and 25
per cent is considered a fair average. Sometimes the nitrate de-
posits are found in the bottom of shallow basins, but more commonly
this position is occupied by the chloride salts, while the nitrate
forms terraces or benches around them. The two salts may, how-
ever, occur mixed indiscriminately. The deposits, whkh where
exposed present a rough and leached appearance, are quite variable
in thickness even over small areas, a depth of several feet fading out
within a few yards to but a few inches. Thicknesses of i to i J to 3
feet are common ; less so are thicknesses of 4 to 6 feet. The over-
lying material, rarely absent, varies from 2 to 20 feet in thickness,
sometimes to even 30 or 40 feet The following section is given for
the Province of Tarapaca.
Loose windblown material, sand and gravel, known as CAoM ., o to several feet
Capping of clay, gravel, and sand, known as CiMra o to 30-40 feet
Crude nitrate, known as Caliche 0-6 "
Earthy Soor of aitia.te beds, known as Coba Indefinite
Stratified clays, sands, and gravels "
' Journal of Geobgy, Vol. XVIII, No. i, Jan. -Feb., 1910.
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As above noted the natural nitrate is ne\'er chemically pure.
The following analyses are selected to show averages :
Per Cent.
5-40
it
0.49
0.047
0.043
S3- SO
V.:'A
0.78
•■93
oj
C.s6
T°„a
61.97
5-'S
I- 13
0.41
0.43
":g
0.94
0-53
a.07
0.79
3t:a
s-00
0.94
It
0.07
33.50
'-7S
100. oo
'1%
100,00
68.00
31. 28
44-00
66.,,
34.11
41-90
0.045
Se\'eral of the analyses showed also traces of calcium and mag-
nesium chlorides, ammonia salts, and sodium chromate. Iodine,
although present in but smaU proportion, is an important constituent,
the commercial supply of it being obtained almost wholly from the
nitrate, in process of refining.
The nitrate deposit b quarried by blasting with a coarse-grained
powder, of which as much as 150 pounds are sometimes used at a
single blast. Neither dynamite nor nitroglycerin is used, as it
would shatter and pulverize the salt so as to occasion a serious loss.
After being brought to the surface the caliche is carefully assorted
by experts, broken into pieces double the size of an orange, and
carted to the refinery establishment, situated on the pampas or on
the seacoast, or carried to Iquique, Pisagua, Patillos, and Anto-
fagasta by rail, all of these places having connection, by narrow-
gauge railways, with the nitrate deposits, and which, consequendy,
are rapidly becoming the chief centers of nitrate production and
export.
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3i8 THE NON-METALLIC MINERALS.
The following map, Fig. 47, from Fuchs and De Laimay's
Traits des Gltes Min^raux, will serve to show the geographic posi-
tion of the deposits.
I Ifatitf tout Olattberiit |;;;»;.S;v^-!iV';)| flUi n/i t^ Svtiittm
Fig. 47. — Map of Chilean nitrate region.
[After Fuchs and De Launay.]
3. NITRO-CALCITE.
Nitro-calcite, or cakium nitrate, CaN208+nH20, is not un-
common as a silky efHorescence on the fioors and walls of dry lime-
stone caverns, and may be extracted in considerable quantities from
their residual clays by a process of leaching. During the war of
1812 the clays upon the floors of Mammoth Cave, Kentucky, were
systematically leached and the dissolved nitrate converted into
0 Got>^lc
NITRATES. 319
potassium nitrate by iiltration through wood ashes. The wooden
tanks and log pipes for conducting the water are still in a remarkable
state of preservation, owing to the dry air of the cavern.
The nitrous earths of Wyandotte Cave in southern Indiana, and
doubtless of other localities, were similarly treated during these
times of temporary stringency.
According to the reports of the State geologist • this earth, in its
air-dry condition, has the following composition:
Percent.
6
S
6
3
60
"i
7S
40
06
S
55
43
so
.00.. 1
1
The researches of Muntz and Marcano ' have shown that the
soils as well as the earth from the floor of caves, in Venezuela and
other portions of South America, may be rich in calcium nitrate to
an extent quite unknown in other countries.
Origin. — ^The original source of the nitrates, both of caves and of
die Chilean pampas, has been a subject of considerable discussion.
There appears little doubt but the deposits in caves and those dis-
seminated in soils are due to the nitrifying agencies of bacteria
acting upon organic matter whereby the organic nitrogen is con-
verted into nitric acid, which immediately combines with the most
available bases, be they of lime, soda, or potash. The accumulation
' Geobgical Report of Indiana, 1878, p. 163.
'Comptes Rendusde VtuaAiiaK dcs Sciences, CI, Paris, 1885, p. 1365.
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330 THE NON-MBTALLIC MINERALS.
of the> niter in caves is probably due, as suggested by W. H. Hess,*
to the retention by the clay of the nitrates brought in from the sur-
face by percolating waters. In other words, the caves serve merely
as receptacles, or storehouses, for nitrates which had their origin
in the surface soil. The Chilean nitrate beds are considered by
Muntz and Marcano as having a very similar origin. The material
being soluble is gradually leached out from the soils in which it
originated and drained into inclosed salt marshes or inland seas
where a double decomposition takes place between the sodium
chloride and calcium nitrate, whereby sodium nitrate and calcium
chloride are produced. That such a double decomposition may
take place has been shown by actual experiment
This is not widely different from the view taken also by W. New-
ton.* After discussing briefly theories previously advanced, includ-
ing Darwin's theory of derivation from decomposing seaweeds
accumulated on old sea beaches, and the even less plausible one of its
derivation from guano, his writer shows that the Tamarugal plain
within which the deposits lie, is covered by an alluvial soil rich in
organic matter. Thb organic matter, under the now well-known
action of bacteria, aided by the prevailing high temperatures of the
region, gives rise to nitrates, which, owing to the absence of rains for
long periods, accumulate to an extent impossible under less favorable
circumstances. Mountain floods, which occur at periods of seven
or eight years, swamp the plain, bringing in solution the nitrate
drained from the soOs of the surrounding slope, to accumulate in
the lower levels. On the evaporation of the water this is again
deposited. The occurroice of the nitrate so far up the slope of the
hills is regarded by Newton as due to the tendency of the nitrate
salt, in saturated solutions, to creep up, as in experiment it may
be seen to creep up and over the sides of a saucer or other shallow
dish in which the evaporatbn is progressing.
Penrose, on the other hand, in the most recent paper bearing
on ihe subject, argues that the nitrogenous matter was derived
from ancient guano deposits which once lined the waters of these
inclosed basins.
' Jounul of Geology, VIII, No. i, 1900, p. 119.
' Geological Magazine, III, 1S96, p. 339.
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Uses. — Munroe • gives the consumption ot nitrate of soda in the
United States for 1905 as 254,772 short tons, which was divided
among the various industries as follows:
In the nuLnufacture of fertiliiers 4i>>i3 tou
" " dyestuffs a6i ■'
" " chemic&ls 38|04^ "
" " glass 11,915 "
" " eiplosiVM 133.034 "
*' *' sulphuric, nitric, and other
acids '--.. i9i3oi "
354t77a "
BIBUOGRAPHY.
U. A. MuNTI. Rechercbes sai la fbrmatioa des gitementi de oiltAte de loude.
Comptes Rendus de I'Acadfmie des Sciences, CI, 1S85, p. 1265.
Ralth Abekceomby. Nitnte oC Soda, nnd the Nitrate Countiy.
Nature, XL, 1889, p. iSi3.
WnxiAM Newton. The Origin of Nitrate in Chile.
The Geological Mapzine, III, 1896, p. 339.
W. H. Hess. The Origin of Nitrates in Caves.
Journal of Geology, VIII, No. 1, 1900, p. 119.
R. A. F. Penkose. The Nitrate Deposits of Chile.
Journal of Geolog)', XVIII, 1910, pp. 1-33.
X. BORATES.
Of the ten or more species of natural borates but three, or pos-
sibly four, are commercial sources of borax, and need consideiation
here. These are, (i) borax or lineal; (2) ulexite, or boronatrocal-
cite; (3) piiceite, colemanite, or pandermite, and (4) boracite, or
stassfurtite. Sassolile, or native boric acid, occurs chiefly in solution.
The intimate association of these minerab renders it advisable to
treat of their origin and mode of extraction in common, after giving
the composition and general physical characters of each by itself.
' The Nitrogen Question, etc. Proceedings U. S. Naval Institute, XXXV, No. 3,
J910, p. 715.
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322 THE N0N-METj4LUC MINERALS.
I. BOKAX OR TINCAL; BORATE OF SODA.
Composition. — Na,BjO,.ioH,0,=boron trioride, 36.6 per cent;
soda, 16.2 per cent; water, 47.2 per cent. Color, white to grayish,
and sometimes greenish; translucent to opaque. It crystallizes in
short, stout prisms, belonging to the monorlinic system. Hardness,
2 to 3,5; specific gravity, 1.7. Readily soluble in water; taste,
sweetish alkaline.
2. ULEXTTE; BORONATROCALCrrE.
COT»^sifi(W.—NaCaB(0,.8H,0, = boron trioxide, 43 per cent;
lime, 13-8 per cent; soda, 7.7 per cent; water, 35.5 per cent. Color,
white, with silky luster. Occurs usually in rounded masses of loose
texture, which consist mainly of fine acicular crystab or fibers. In-
soluble in cold water, and only slightly so in hot, the solution being
alkaline. Hardness, i; specific gravity, 1.65.
3. COLEUANrrE.
Composition. — Ca,BoOi,.5H,0,- boron trioxide, 50.9 per cent;
lime, 27.2 per cent; water, 21.9 per cent. Color, milky to yellowish
white, or colorless; transparent to translucent. Hardness, 4 to 4.5;
specific gravity, 2.41. Insoluble in water, but readily so in hot hydro-
chloric acid. Priceite and pandermite are closely allied varieties
occurring in loosely coherent and chalky or massive forms.
4. BORACITE OR STASSFURTITE ; BORATE OF MAGNESIA.
Composition. — Mg,Cl,Bi,Oj„, = boron trioxide, 62.5 per cent; mag-
nesia, 31.4 per cent; chlorine, 7.9 per cent. Color, white to yellow
or greenish. In crystals transparent to translucent. Crystals cubic
and tetrahedral. Insoluble in water; readily soluble in hydrochloric
acid. Hardness, 7; specific gravity, 2.9 to 3.
Localities and manner 0} occurrence 0} ike borates. — Throughout
what is known as the Great Basin region of the western United States,
and in particular that portion including Inyo, Kern, and San Bernar-
dino coimties in California, and that portion of southwest Nevada
0 Got>^lc
BORATES. 323
adjoining Inyo County, are numerous inclosed lakes or marshes, the
waters of which are sufficiently rich in borates and other sodium
salts to allow of their extraction on a commercial scale. At least
ten of these marshes have been noted along the Califomia-Nev'ada
line, the most widely known being Teels, Columbus, and Rhodes
marshes, and Fish Lake Valley in Nevada, and Searles Marsh in San
Bernardino County, California. A detailed description of the last
named will serve all purposes of illustration here.'
Locally considered, the marsh lies near the center of an exten-
sive mountain-girdled plain, to which the names " Alkali Flat,"
" Dry Lake," " Salt Bed," and " Borax Marsh " have variously
been applied. It is, in fact, a dry lake, the bed of which has been
filled up in part with the several substances named. Its contents
consist of mud, alkali, salt, and borax, largely supplemented with
volcanic sand. This depression, which has an elevation of 1,700
feet above sea-level, and an irregular oval shape, is about 10 miles
long in a north and south direction, and 5 miles wide. It is sur-
rounded on every side but the south by high mountains, the Slate
Range boimding it on the east and north, and the Argus Range on
the west
What may have been the depth of the lake has not yet been ascer-
tained, borings put down 300 feet having failed to reach bed rock.
These borings, commenced in 1878, disclosed the following under-
lying formations:
First, 2 feet of salt and thenardite (Na2S04); second, 4 feet of
clay and volcanic sand, containing a few crystals and bunches of
hanksite {4Na2SOi,Na2C03) ; third, 8 feet of volcanic sand and
black, tenacious clay, with bunches of trona, of black, shining luster
from inclosed mud; fourth, 8-foot stratum, consisting of volcanic
sand containing glauberite, thenardite, and a few flat, hexagonal
crystals of hanksite; fifth, 28 feet of solid trona of uniform thickness;
sixth, 20-foot stratum of black, soft mud, smelling strongly of sul-
phureted hydrogen, in which there are layers of glauberite, soda,
and hanksite; seventh, 230 feet (as far as explored) of brown clay,
mixed with volcanic sand and permeated with sulphureted hydrogen,
' From tbe Tenth Annual Report (dtbeSute Mineralogist of Califomk, i8go,p.534.
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334
THE NON-METALUC MINERALS.
While most of the water contained in this basin is subterranean,
a little from atmospheric sources accumulates during very wet winters
and stands for a short time on portions of the surface. In no place,
however, does it reach a depth of more than a foot or two, hardly
anywhere more than 3 or 4 inches.
The water of the lake is of a dark-brown color, strongly impreg-
nated with alkali, and has a density of 28° Baum^. The salts ob-
tained from it by crystallization contain carbonate and chloride
and borate of sodium, with a large percentage of organic matter.
Summarized, the following minerals have been found associated
with the borax occurring in the Searles Marsh; Anhydrite, calcite,
celestite, cerargyrite, colemanite, dolomite, embolite, gay-lussite,
^uberite, gypsum, halite, hanksite, natron, soda, niter, sulphur,
thenardite, tincal, and trona, the most of them occurring in only
small quantities.
The submerged tract above described is called the " Crystal Bed,"
the mud below the water being full of large crystals, which occur in
nests at irregular intervals to a depth of 3 or 4 feet Many of these
crystals, which consist of carbonate of soda and common salt with
a considerable percentage of borate, are of large size, some of them
measuring 7 inches in length. The water 15 feet below this
stratum of mud contains carbonate of soda, borax, and salts of
ammonia. The ground in the immediate vicinity, a dry, hard crust
about I foot thick, contains:
CoratituenM.
PerCmt,
16
The borax here occurs in the form of the borate of soda only, no
ulexite (borate of lime) having yet be«i foimd.
About 1890 it was discovered that these marsh deposits were all
secondary, the borax contents being derived from bedded deposits
of colemanite in the Tertiary lake sediments of the surrounding
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BORATES. 325
hills. The marshes were, therefore, very gener^y abandoned in
favor of the beds. What was, until recently, the most important
of these deposits b at a locality appropriately named Borate, some
12 miles north of Da^ett in the old Calico Mining District. The
mineral colemanite — the borate of lime — occurs here in beds of
from 3 to 5 feet thickness interstratified v'th lake sediments which
Fig. 48.— Section of tilted borate beda, Furtuce Valley, California.
I. Andesile (exposed) 500 ft
9. Clay-sbale, blue above, yellowish below 1000 "
3. Gravels, coarse, little or no clay 300 "
4. Basalt TOO "
5. Shale, argillaceous and sandy, buff 300 "
Unconformity.
6. Clay, ^aly, colenunite in laige nodules and nodular layers 50"
J. Clay, shaly, dive-green to yellow 60"
8. Basalt, surface-flow 100"
g. Clay, ahaly, yellow to green 150 "
10. Sandstone, friable, red in cobr »S "
11. Clay, shaly, pale yellow 500"
II. Basalt, black, surface-flow 50 "
13 Clay, shaly, argillaceous, yellowish. aoo "
14. Clays and gravels, pale reddish-brown and purple 500 "
Unconformity, very marked.
[After C. R. Keyes, Bulletin of the American Institute of Mining Engineers, 1909.]
are composed of semi-indurated clays, sandstones, and coarse con-
glomerates with sheets of volcanic tuffs and lava. At the mine,
according to Messrs. W. H, Storms ^ and M. R. Campbell,^ there
are two outcrops some 50 feet apart, representing two distinct beds
or perhaps a repetition by folding of what was originally one and
the same bed. These throughout their extent vary from g to 30
feet in thickness, and have a strike approximately east and west,
' Eleventh Annual Report of the State Mineralogist of California, 1S93, p. 345.
* Bulletin No. 300, U. S. Geological Survey, Series A, Economic Geology, p. j.
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THE NON-METALLIC MINERALS.
dipping to the south from io° to 45°. The lake beds extend across
the mountains for a distance of 8 miles, but the borax deposit, so
far as yet discovered, has a practical limit of not above a mile and
a half. The illustration (Plate XXX), conveys better than words
PA 0 I r I o
o 0 B A TT
Fig. 49. — Sketch map of CaliCornia borax localities.
[AfterC R. Eejes, Bulletin of the American Institute of Mining Engineers, 1909.]
an idea of the character of the desolate country in which the borax
occurs, and also the method of mining.
For a decade or more, according to C. R. Keyes,^ the mines at
Daggett were the chief source of borax in the United States. Re-
cently extensive developments have taken place in Fimiace Canon
in Death Valley and in the Santa Clara Valley, south of the Sierra
Madre and west of Daggett. (See map. Fig. 49.) At the first-
named locality the borax deposits lie in a deep valley and canyon
between high mountain ranges, and in beds consisting mainly of
' Borax Deposits of the United States, Bulletin American Institute of Mining
Engineers, October, 1909, pp. 1-37.
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BORATES. $aj
soft clays, and sands or friable sandstone, the mountains on either
hand being composed of eruptive and metamorphic rocks.
The rich borate beds are from a few inches to 50 feet in thick-
ness, often highly tilted and folded as shown in the accompanying
^ical section (Fig. 48). They are described as consisting of bluish
clays, thickly interspersed with milk-white layers, nodular bands and
nodules of crystallized colemanite, the clays yiekling by leaching
from 10 to 25 per cent of boric acid. Mingled with the colemanite
there is often much selenite in large plates.
In the Santa Clara Valley the entire borax-bearing formation
is described as from 5,000 to 8,000 feet in thickness, consisting
mainly of fine, more or less indurated gravel, yellow sandstone and
clays. I'he beds have been much faulted and flexed and intruded
by dikes of igneous rocks.
Borax in the form of colemanite (priceite) has also been foimd
about 5 miles north of Chetco, in Curry County, Oregon.
A borax deposit in form somewhat resembling the marsh deposits
of Nevada and California already referred to occurs in Hamey
County, southeastern Oregon. The region is extremely flat and
bare of all vegetation, the immediate surface of the ground being
covered for a depth of several inches with a white incrustation con-
sisting of the borate contaminated with carbonate, sulphate, and
chloride of sodium.'
The chief foreign sources of borax salts are Northern Chile,
Stassf urt in Germany, Italy, Asia Minor, and Thibet
The Chilean mineral is ulexite and is reported as occurring
throughout the province of Atacama and the newly acquired por-
tions of Chile. Ascotan, which is now on the borders of the Republic,
but formerly belonged to Bolivia, and Maricunga, to the north of
Copeapo, are the places which have proved most successful com-
mercially. The crude material occurs in both places in lagoons
or troughs. Those of Maricunga lie about 64 kilometers from the
nearest railway station, and are estimated to cover 3,000,000 square
meters. The boronatrocalcite occurs in beds alternating with layers
of salt and salty earth. The crude material contains, in the form of
gypsum and glauberite, a large amount of calcium sulphate.
' W. B. Deimu, Eogineeriiig and MiniDg Journal, April 36, igoa, p. j8i.
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328 THE NON-METALLIC MINERALS.
Recentiy deposits have been described in the dry bed of Lake
Salinas, about 12 miles east of Arequipa City. The borate is
in the fonn of ulexite and in a massive impure form known zs
corrierUe. A section of the deposit shows (i) chloride and sulphate of
soda and fine sand 10 to 14 cm.; (2) gravel 6 cm.; (3) sand with
layers of the borate 20 to 50 cm. ; (4) fine sand and borate in variable
thicknesses 40 cm. to i meter. Thelake lies at an altitude of 14,200
feet and is surrounded by high mountains, many of which are
volcanic.*
Dana also mentions ulexite as occurring in the form of rounded
masses from the size of a hazelnut to that of a potato in the dry
plains of Iquique, where it is associated with pkkeringite, glauberite,
halite, and gypsum.
The German mineral is boracite (stassfurtite) and is found in
small granular masses associated with the salt deposits of Stassfurt.
In Italy sassolite, or crystallized boric acid, has long been obtained
by the evaporation of the water of hot springs in Siena, in Tuscany.
Concerning the deposits of Asia Minor litde is accurately known.
The mineral is pandermite (colemanite), which is found in thick
white lumps at Suzurlu, south of the sea of Marmora. Borax or
tincal, from Thibet, in Nortiiem India, was probably the first of
the boron salts to be utilized. It b stated to have been brought on
the backs of sheep from the lakes in which it is formed across the
Himalayas to the shipping points in India,
Methods of mining and manufacture. — At the East Calico Cole-
manite Mine, in San Bernardino County, the borax mineral is taken
out in the same manner as ores of the precious metals. Inclined
shafts are sunk, drifts and levels run, and slopes carried up as in
any other mine. The material, when hoisted to the surface, i&
loaded into w^ons and hauled to Daggett, whence it is shipped to
the works at Alameda, where it is purified.
At Searle's marsh the overlying crust mentioned constitutes the
raw material from which the refined borax is made. The method
of collecting it in the past has been as follows: When the crust,
through the process of efflorescence, has gained a thickness of about
' Engineering and Mining Jounial, LXXXIV, 1907, p. 780.
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BORATES. 329
I inch, it is broken loose and scraped into windrows far enough
apart to admit the passage of carts between them, and into which
it b shoveled and carried to the factory located on the northwest
nxargin of the flat, i to 2 miles away.
As soon as removed, this incrustation begins again to form, the
water charged with the saline matter brought to the surface by the
capillary attraction evaporating and leaving the salt behind. This
process having been suffered to go on for three or four years, a
crust thick enough for removal is again formed, the supposition
being that this incrustation, if removed, will in Uke manner go on
reproducing itself indefinitely.'
At the Harney County, Oregon, works the crude material is care-
fully shoveled up during the summer into small conical heaps, the
crust continually renewing itself, so that the same ground is worked
over repeatedly. This crude material, which contains from g to
30 per cent boric acid, is refined by throwing into tanks of hot water
into which small amounts of chlorine or sulphuric acid are introduced.
The various salts are all dissolved and subsequently separated one
from another by fractional crystallization.
' In order to detennine the proportionate growths of the various salts contained
In this crust while undergoing this recuperative process, analyses were made on sam-
ples representing respectively six months', two, three, and four years' growth. From
the ground from which these were taken the crust had been removed scveial times
during the preceding twelve years.
The analysis of samples gave the follovring results:
ConitituenW.
Six
Grewih.
Two
Yun'
Thne
Yon'
Grawth.
Four
Growth.
S8.0
11.7
14-1
SS-4
IJ,9
'11
16.6
Ills
16.0
II.S
10.9
Carbonate of soda . . .
Sulphate of soda
Chloride of soda
■00.0
.00.0
,00.0
■CO.O
From this list it will be seen that the first six months' growth is richest in borai^
and that the proportion of carbonate of soda lo borax increases with time. The
presence of so much sand as is here indicated is caused by the high winds that blow
at intervals, bringiog in girat quanlities of that material from Che mounUiins to the
west. This sand, it is supposed, facilitates the formation of the surface crust by
keeping th« ground in a porous condition.
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THE NON-METALLIC MINERALS.
XI. URANATES.
1. uraninite; pitchblende.
Composition very complex, essentially a uranate of uranyl, lead,
thorium, and other metals of the lanthanum and yttrium groups.
The mineral is unique in containing nitrogen, argon, helium and
radium. The analyses given below are for the most part by HUle-
brand, to whom is due the credit of a large share of the present
knowledge on the subject
LociHty.
UO^
uo^
ThO^ 1 CfO,. 1 L*JD» [ Y,0>
13.03
50-83
30.63
l9-i°
59-93
39-3>
46.13
ia.33
Glastonbury, ConDccticut..
1.78
6.00
o.a6
0.18
0.S0
0.37
AnnerSd, Norway
...I
Locality.
PbO.
CO.
N.
Hfi.
PeA.
»b..
Glastonbury, Connecticut..
3-^
9.04
6-39
oiss
0-37
0.37
1.17
0-43
0.74
3->7
O.M)
4.66
5-53
AnnerSd, Norway
Johanngeorjenstadt
Several varieties of uraninite are recognized, the distinctions being
based upon the relative proportions of the two oxides UOj and
UO, (see analyses above). Inasmuch, however, as these variations
may be due merely to oxidation they need not be taken into considera-
tion here. When crystallized the mineral assumes oaahedral and
dodecahedral forms, more rarely cubes. Hardness, 5.5; specific
gravity, 9 to 9.7. Color, grayish, greenish to velvet-black, streak
brown; fracture conchoidal, uneven. The massive and probably
amorphous variety is known under the name of pitchblende. This
last is the chief commercial source of uranium salts, and is the
common " ore " of radium. Through oxidation and hydration
the mineral passes into gummite, a gum-like yellow to brown or red
mineral of a hardness of but 2.5 to 3 and specific gravity of 3.9^0 4.2.
Localities and mode of occurrence. — Uraninite occurs as a pri-
mary constituent of granitic rocks and as a secondary mineral, with
sulphide ores of silver, lead, gold, copper, etc. In this last form,
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URANMTES. 331
according to Dana, it is found at Johanngeorgenstadt, Marienberg,
and Schneeberg, Saxony; at Joachimsthal and Pribram, in Bohemia,
and Rezbknya, in Hungary. Considerable quantities have been
mined from the tin-bearing lodes of Cornwall, England. The
crystallized variety broggerite is found in a pegmatite vein near
Annerod, Norway, and the variety cleveite in a feldspar quarry at
Arendal. In the United States the mineral has been found in small
quantities in several localities, but only those of Mitchell and Yancey
counties. North Carolina, where the mineral occurs partially altered
to gummite and uranaphane, in mica mines; Llano County, Texas;
Black Hawk, near Central City, Gilpin County, Colorado, and
the Bald Mountain district of the Black Hills of South Dakota need
here be mentioned. Of the above the Cornwall localities are at
present of greatest consequence, having during 1890 yielded some
22 tons of ore, valued at some £2,200 ($ii,oco). During 1891, it
is stated, the output was 31 long tons, valued at ;£62o, and in 1892,
37 tons, valued at £740. The next most important locality is that
of Joachi nsthal, in Bohemia, where 22.52 metric tons of ore were
produced in 1891 and 17.71 tons in 1892, the value being some 1,000
florins a ton.
In the Cornwall mines the pitchblende is stated' to occur in small
veins crossing the tin-bearing lodes. At the St. Austell Consols
Mines it was associated with nickel and cobalt ores; at Dolcoath
with native bismuth and arsenical cobalt in a matrix of red quartz
and purple fluorspar; at South Tresavean with kupfer- nickel, native
silver, and argentiferous galena. At the Wood Lode, Russell dis-
trict, in Gilpin County, Colorado, pitchblende was found in the form
of a lenticular mass in one of the ordinary gold-bearing lodes trav-
ersing the gneiss and mica schists of the district. The body occurred
some 60 feet below the surface and was some 30 feet bng by 10 feet
deep and 10 inches thick. The mass yielded some 4 tons of ore
carrying 70 per cent oxide of uranium.
Other natural uraniimi compounds, but which at present have
no use in the arts, are as below: Torbenite, a hydrous phosphate
of uranium and copper (see p. 307) ; autunite, a hydrous phosphate
' The Mineral InduiCry, II, p. 57a.
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332 THE NON-METALLIC MINERALS.
of uranium and calcium; zeunerite, an arsenate of uranium and
copper; uranospinite, an arsenate of uranium and calcium; uran-
ocircite, a phosphate of barium and uranium; phosphuranylite, a
hydrous uranium phosphate; triigerite, a hydrous uranium arsenate;
walpurgite, probably an arsenate of bismuth and uranium; and
uranosphsrite, a uranate of bismuth.
Uses. — Uranium is never used in the metallic state, but in the
form of oxides, or as uranate of soda., potash, and ammonia, finds a
limited application in the arts. The sesquioxide salt imparts to
glass a gold yellow color with a beautiful greenish tint, and which
exhibits remarkable fluorescent properties. The protoxide gives a
beautiful black to high-grade porcelains. The material has also a
li-nited application in photography. Recently the material has been
used to so ne extent in making steel in France and Germany, but
the industry has not yet passed the experimental stage. It has been
stated that the demand, all told, is for about goo tons annually.
Should larger and more constant sources of supply be found, it is
probable its use could be considerably extended. According to
Nordenski H, ;£50,ooo worth of uranium minerals are consumed
every year, the various salts produced being used in porcelain and
glass manufacture, in photography, and as chemical reagents. The
material has of late — in the public mind at least — possessed an
almost sensational interest in connection with the discovery of its
radio-active properties, and the new elements radium and poloi
of which it forms the chief conunercial source.
2. CARNOnXE
The name camotite was given in 1S99 by MM. £. Cumenge
and C. Friedel to a beautiful canary-yellow ocherous pigment which
was found impregnating a siliceous sandstone in Montrose County,
Colorado. Material from the same and other sources has since been
examined by Dr. W. F. Hillebrand,i whose results show the material
to be not a simple mineral, but a mixture made up in large part of
an impure uranyl-vanadate of potash and the alkaline earths. The
* AmericaD Jountal of Science, X, August, 1900.
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URANATES.
333
composition of material from (i) the Copper Prince claim, Roe
Creek, and (2) the Yellow Boy claim, La Sal Creek, and in Mon-
trose County, as shown by Hillebrand's analyses, is given below:
f CABNonrE 7E0U coumAoo.
Insoluble .
UO,
V.O,
P.O.
Aa,0,....
AlO
Fe,0,....
CaO
SrO
BaO
MgO....
K,0
Sb°;:::
H-O, io5«
50. 350"
P50
CuO
SO,
MoO,....
SiO-
TiO,
CO,
Total.
■6S
.14
6-57
Occurrence. — ^As above stated, the material is found in sandstone.
F, L. Ransome ' describes the La Sal Creek deposit as occurring in
irregular bunchy pockets, the ore bodies being usually flat-lying
streaks but a few inches thick grading both above and below into
the common light-buff sandstone, the camotite gradually dying out
until the rock shows no trace of the mineral. At Roe Creek the
camotite occurs in a nearly horizontal sandstone which has been
cut by a fault-plane dipping about 75° N. The material is here
found in the hanging-wall of the fissure in the form of small, irregular
branches in a loose mass of crushed sandstone and also as an im-
' American Toumal of Science, X, August, 1900.
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334 THE NON-METALLIC MINERALS.
pregnation of some of the finer portions of the bed, the impregDation,
as at La Sal Creek, taking place mainly along the bedding planes.
In all cases thus far reported the deposits are su[>erficial and appar-
ently result " from a local concentration of material already existing
in the sandstone . . . under conditions determined by proximity
to the surface."
Camotite is also found impregnating the Dakota (Cretaceous)
sandstone of Rio Blanco County in the same State.
Uses. — The material has been used to some extent as a source
of uranium and vanadium salts.
XII. StJLPHATES.
I. bakite; heavy spas.
Composition. — BaSO„ = sulphur trioxide, 34.3 per cent; baryta,
65.7 per cent; specific gravity, 4.3 to 4.6; hardness, 2.5 to 3.5.
The sulphate of barium to which the mineralogical name of
barite is given occurs, as a rule, in the form of awhile, translucent to
transparent, coarsely crystalline mineral, about as hard as common
calcite, but from which it may be readily distinguished by its great
weight and its not effervescing when treated with acid. A common
fonn of the mineral is that of an aggregate of straight or somewhat
curved plates, separating readily from one another when struck with a
hammer, and cleaving readily into rhomboidal forms much like
calcite. It is also found in globular and nodular concretions, stal-
actltic and stalagmitic, granular, compact, and earthy masses, and
in single and clustered broad and stout crystab. In nature the
material is rarely pure, but nearly always contaminated with other
elements, as noted in the following analyses of samples from Fulton,
Blair, and Franklin counties, Pennsylvania.'
' Peniisj'lvania Second Geological Survey, Chemical Aaalytes, pp. 56S, 569.
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SULPHATES.
CoMtitucnts.
p.,,„o..„.
BUir
County.
PrankBil County.
„
Q6.91
0.31
None.
Trace.
Trace.
None.
0.08
a.35
97.08
0.76
None.
None.
Trace.
None.
0.31
1.74
9591
None.
0.17
None.
2.80
98.6s
Oxides of iron and aluminum.
I
05
65
'AS
99"
99-65
99-90
99-3»
100 10
Occurrence. — The mineral is a common accompaniment of me-
tallic ores, but as such has not proven of any value commercially.
Such deposits as have been worked for the mineral itself are, as a
rule, pockety or lenticular masses mainly in limestone and following
the dip and strike of the rocks with which they are associated. In
Washington County, southwest Virginia, the mineral occurs in
coarsely cleavable masses 'n certain beds of the Cambrian limestone,
fillii^ irregular fractures or at times replacing the limestone itself.
In Tazewell County; this same State, it is described as occurring
in a series of lenticular pockets having a general northeast-southwest
strike, and dipping from 20° to 30° toward the east. The general
widthof this seriesof pockets is given' as from 100 to 200 or more feet
and occurring over an area some 4 miles in length. The pockets
are at times quite distinct from one another, or again may be coimected
by a thin seam of barite. In Madison and Gaston counties. North
Carolina, the material is found in a seam or vein from 3 to 6 feet in
width in a decomposed schist.
In Missouri barite occurs in cavities in a dolomite of Ordovician
age, the cavities, according to A. A. Steel,^ being due in part to a
shattering which he regards as incidental to dolomitization, and in
part to Assuring and faulting, in either case being subsequently
* J. H, Fiatt, Mineral ResouTces of the United States, 1901, p. 915.
' Bulletin American Institute of Mining Engineers, No. jS, February, 1910.
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■ 33^ THE NON'METALUC MINERALS.
enlarged by solution. The barite filling was probably a result of a
process of concentration by leaching from the country rock, though
its primary source was undoubtedly the pre-existmg igneous rocks
forming the neighboring ancient land areas. The chief barite-pro-
ducing ground is at present eastern Washington County, the mineral
being mined in nodular masses from the residual clay. The average
yield, mainly from open
cuts and trenches, is
about 600 tons per acre.
Where mined to a depth
of 8 feet, yidds as high
as 2,500 to 4,000 tons
per acre have been re-
ported.
The principal local-
ities in the United States
where barite has been
mined on a commercial
Fio. ^o. — Ideal section of Bennett Barite Mine, 1 - i-> .- ,
''„.,. ^ ,„.. . ' scale are m Connecticut,
Pittsylvania County, Virginia. . . _ "^.-i.,
[After Watson, Mineral Resources o£ Virginia.] Vkginia, North Carolina,
Tennessee, and Missouri,
though the first-named State has ceased to be a producer. The min-
ing is almost wholly from open cuts, the cheapness of the material
militating against the expense of deep mining. When occurring
in limestone the material is found superficially in loose nodules
and fragments embedded in the residual clay resulting from its
decomposition. In Missouri and Tennessee it is often associated
with a small amount of galena.
Preparalion and uses. — The mineral is washed and ground like
grain between millstones and used as an adulterant for white lead
or to give weight and body to certain kinds of cloth and paper. Con-
siderable quantities are utilized in the preparation of barium salts
for various chemical purposes.
According to a writer in the Mineral Resources of the United
States for 1885, the " floated " or " cream-floated " barite used as
paint is prepared as follows: The crude mineral as mined is first
ov Google
sorted by hand and cleaned, after which it is crushed into pieces
about the size of the tip of one's finger. Next it is refined by boiling
in dilute sulphuric acid until all the impurities are removed, when it
is washed by boiling in distilled water and dried by steam. It is then
ground to flour, mixed with water, and run through troughs or sluice-
ways into receiving vats, whence it is taken, again dried by steam,
and barreled. The crude material is worth only about $3.50 per
ton.
2. GYPSDH.
Composition. — CaS04+2H,0, — sulphur trioJtide, 46.6 per cent;
lime, 32.5 per cent; water, 20.9 per cent. The natural mineral is
often quite impure through the presence of organic, ferruginous,
and aluminous matter, tc^ether with small qnantities of the carbon-
ates of lime and magnesia {see analysis, below). Specific gravity,
2.3; hardness, 1.5, to 2. Color, usually white or gray, but brown,
black, and red through impurities. The softness of the mineral, which
is such that it can be easily cut with a knife, or even by the thumb
nail, is one of its most marked characteristics. Three principal
varieties are recc^nized, (i) the crystallized, foliated, transparent
variety, selenite, (2) the fine fibrous, often opalescent variety,-
satin spar, and (3) the common massive, finely granular variety,
gypsum. When of a white color and sufficiently compact for
small statues and other ornamental works, it is known as alabaster,
though this name has unfortunately become confounded with the
calcareous rock travertine and stalagmite.'
The following is an analysis of a commercial gypsum from Ottawa
County, Ohio, as given by Professor Orton:^
PerCret
3^.52
45 -SO
ao.i4
V.\t
0.6S
99.61
■ See The Oayi Marbles, their Origin, Umt, etc.. Report of the U. S. Nadoiul
Museum, 1893, pp. 539-585.
■ Geotogr of Ohio, VI, 1S&8, p. 700.
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338 THB NON-METALLIC MINERALS.
Origin. — Gypsum in considerable quantities occurs associated
only with stratified rocks, and is regarded mainly as a chemical de-
posit resulting from the evaporation of waters of inland seas and
lakes ; it may also originate through the decomposition of sulphides
and the action of the resultant sulphuric acid upon limestone; through
the mutual decomposition of the carbonate of lime (limestone) and
the sulphates of iron, copper, and other metals; through the hydra-
tion of anhydrite and through the action of sulphurous vapors and
solutions from volcanoes upon the rocks with which they come in
contact. According to Dana,' the gypsum deposits in western New
York do not form continuous layers in the strata, but lie in embedded,
sometimes nodular masses. In all such cases, this authority says,
the gypsum was formed after the beds were deposited, and in this
particular instance are the product of the action of sulphuric acid
from springs upon the limestone. "This sulphuric acid, acting on
limestone (carbonate of lime), drives off its carbonic acid and makes
sulphate of lime, or gypsum; and this is the true theory of its forma-
tion in New York." Dr. F. J. H. Merrill, however, regards a por-
tion at least of the New York beds as a product of direct chemical
precipitation from sea water,*
The gypsum of northern Ohio is regarded by Professors New-
berry and Orton as a deposit from the evaporation of landlocked
seas, as was also the rock salt which overlies it. By this same proc-
ess must have originated a large share of the more recent gypsum
deposits of the Western States.
Geological age and mode oj occurrence. — As may be readily inferred
from the above, beds of gypsum have formed at many periods of the
earth's history, and are still forming wherever proper conditions
exist. The deposits of New York State occur in a belt extending
eastward from Cayuga Lake and in beds belonging to the Saliita
period of the Upper Silurian Age. The rock is often earthy and
impure, and is used nearly altogether for Land plaster. It is asso-
ciated with dark, nearly black, limestones and shales and beds of
rock salt- In southwest Virginia, along the Holston River, are also
'Manual of Geology, p. 334.
> Bulletin No. 11 of the New York State Musei:m, April, i
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PLATE XXXr.
Gypsum Quarry, Fori Dodge, Iowa.
[From photograph by Iowa Geological Survey.
[fl7.,«„&"^Oglc
J, Google
SULPHATES. ^Z9
beds of gypsum associated with salt and referred by Dana to thia
same horizon. The rock is mined at Saltville in Washington County
from underground pits, and is used mainly for fertilizing.
Gypsum deposits of varying thickness and occurring at various
depths below the surface are found continuous over thousands of
square miles in northern Ohio, but are at present worked only in
Ottawa County at a station on the Lake Shore and Michigan South-
em Railway which bears the appropriate name of Gypsum. The
associated rocks are Lower Helderberg limestones and shales, and
the beds, which vary from 3 to 7 feet in thickness, are found at all
depths up to 200 or 300 feet.
The following is a section of the Ottawa County beds as given by
Orton:*
Feel.
Drift clays 12 to 14
No. I. Gray rock, carrying land plaster 5
Blue shale ^
No. 2. Bowlder bed carrying gypsum in separate masses
embedded in shaly limestone ,' 5
Blue limestone, in thin and even courses i
No. 3. Main plaster bed 7
Gray limestone in courses i
No. 4. Lowest plaster bed, variable 3 to 5
Mixed Umestone and plaster, bottom of quarry.
Sections like the above are stated to be capable of yielding 50,000
tons of plaster an acre.
The purest gypsum of the region occurs in No. 2, the bowlder
bed, as given above. It consists of calcareous shales through which
are scattered concretionary balls of gypsum varying in diameter from
6 to 24 inches. This pure variety is used mainly for terra alba; about
40 per cent of the total product has in years past been calcined for
use as stucco or plaster of Paris and 60 per cent for land plaster.
At Fort Dodge, in Iowa, is a deposit of quite pure, light-gray,
regularly bedded gypsum, restii^ unconformably upon St. Louis
Umestone and lower coal strata and overlain by drift. It is supposed
' Gc<rfogiul Survey ol Ohio. Economic Gecdogy, VI, 186S, p. 698.
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340 THE NOW-METALLIC MINERALS.
to cover an area of some 25 square milca. The material was at one
time used for buflding purposes, but proved too soft' and is now-
used mainly for land plaster. (See Hate XXXI.)
There are large deposits of gypsum in Michigan, the most exten-
sive, so far as explored, being near Grand Rapids, Kent County, in
the western part of the State, and at Alabaster Point, in Iosco County,
on the eastern margin of the State. At both localities there is a
succession of beds beginning at or near the surface and aggregating
many feet in depth. The beds are regarded as of Carboniferous
age. The following section shows the number and thickness of the
beds thus far discovered:
Feet.
Earth stripping 20
Gypsum 8
Soft shale, slate i
Gypsum 13
Shale or clay slate 7
Gypsum 6J
do ^
Slate, shale 3 J
Gypsum 12J
Shale or clay slate i\
Gypsum 9 J
Shale, clay slate 8
Total 98
In Kansas are notable deposits of gypsum associated with rocks
regarded by Haworth' as of Permian age. The most important
beds so far as now known are in Marshall and Barber counties.
Southwest of Medicine Lodge in the last-named county the material
occurs in beds from 30 to 30 feet in thickness and covering many
square miles of territory.
West of the front range of the Rocky Mountains are many impor-
tant beds of gypsum, but which have as yet been but little exploited
* Stones for Building and Decoration, 2d ed., 1S97, p. 76.
' Mineral Resources of Kansas. 1897.
J, Google
SULPHATES. 341
owing to cost of transportation, there being but little local demand.
These beds so far as yet worked are mostly of more recent origin
than those in the eastern United States, many being of Tertiary or
even Quartemary Age.
Near Fillmore, Utah, are deposits of gypseous sand formed by the
winds blowing up from the dry beds of playa lakes the minute crys-
tals deposited by evaporation. The material thus blown tt^ether
forms veritable dunes from which the material may be obtained by
merely shoveling. Prof. I. C. Russell has estimated these dunes to
contain not less than 450,000 tons of gypsum.
Important deposits of gypsum also occur in Colorado, South
Dakota, Wyoming, California, New Mexico, Oklahoma, and Texas.
Gypsum is a very abundant mineral in New Brunswick, the
deposits being numerous, large, and in general of great purity. They
occur in all parts of the Lower Carboniferous dbtrict in Kings,
Albert, Westmoreland, and Victoria, especially in the vicinity of
Sussex, in Upham, on the North River in Westmoreland, at Martin
Head on the bay shore, on the Tobique River in cliffs over 100 feet
high, and about the Albert Mines. At the last-named locality the
mineral has been extensively quarried from beds about 60 feet in
thickness,' The mineral is usually met with in very irregular masses,
associated with red marls, sandstones, and limestones, and varies
much in character. At Hillsborough considerable masses of very
beautiful snow-white gypsum or alabaster are also met with, and a
little selenite. At Petitcodiac the deposit has a breadth of about
40 rods and total length of about i mile. The whole bed is fibrous
and highly crystalline and traversed through its entire extent by a
vein of nearly pure selenite, 8 feet wkle. The rock on the Tobique
River, which rises in bluffs along the stream some 30 miles above
' Dawaon's Acadian Geology, p. 149,
J, Google
342 THE NON-METALLIC MINERALS.
its mouth, is mostly soft, granular or fibrous, and of a more decidedly
reddish color than in the other localities.
Im[>ortant beds of gypsum belonging to the same geological hori-
zon likewise occur in Nova Scotia, particularly at Wentworth and
Montague in Hants County, at Oxford, River Philip, Plaster Cove,
Wallace Harbor, and Bras d'Or Lake, Cape Breton. At Wentworth
there are stated to be " cliffs of solid snowy gypsum from loo to 200
feet in height."
Gypsum deposits occur in the Onond^a formations of Ontario,
Canada, and are exploited along the Grand River between Cayuga
and Paris. The mineral here occurs in lenticular masses varying
from a few yards to a quarter of a mile in horizontal diameter and
from 3 to 7 feet in thickness,
The foreign sources of gypsum are almost too numerous to men-
tion. Important beds occur in Lincolnshire and Derbyshire, Eng-
land; near Paris, France; in Spain, Italy, Germany, Austria, and
Switzerland. The Paris beds are of Tertiary Age, and the mineral
. carries some 10 to 20 per cent of carbonate of lime, together with
silica in a soluble form. The presence of these constituents is stated
to cause the plaster to set much harder, permitting it, therefore, to
be used for external work. The Italian gypsum is often of great
purity. The finest alabaster is stated to come from the Val di Marmo-
lago, near Castellina.
Uses. — ^These have been already, in part, noted. The principal
use of the ordinary massive varieties is for fertilizers (land plaster),
and in the manufacture of plaster of Paris, or. stucco. The New
York material is also used in the preparation of the so-called adamant
cement for wall plaster.
As above noted, gypsum is but little used for building purposes,
being too soft. Several residences, a railway station, and other
minor structures are, however, stated to have beeii built of this stone
at Fort Dodge, in Iowa. The variety satin spar is sometimes used
for small ornamentations, but it is only the snow-white variety -(ala-
baster) that is of any economic importance as an ornamental stone.
The main use of alabaster is for small statues, vases, fonts, and small
columns; it is too soft for exposed positions where subjected to
much wear. At present there are not known any deposits of ala-
ovGoc^lc
SULPHATES. 343
baster within the limits of the United States which are of sufficient
■purity and extent to be of commercial value. A large share of the
alabaster statuettes now on our markets are of Italian make as well as
of Italian materials.
In preparing the gypsum for market the stone is first broken in a
crusher into pieces of the size of a hickory nut, after which it is ground
between millstones (French buhrstones) to a proper degree of fine-
ness and then put up in bags or barrels, if designed for land plaster;
if for stucco it is calcined after being ground. This process is in
Michigan carried on in lai^e kettles some 8 feet in diameter, and
capable of holding about 14 barrels at a chaise. The powder is
heated until all the included water is driven off, being subjected to
constant stirring in the mean time, and is then drawn off through
the bottom of the kettles and conveyed by carrying belts and spouts
to the packing room.*
Under the name of "terra alba" (white earth) ground gypsum
is used as an adulterant in cheap paints.
The commercial value of gypsum depends mainly on accessibility
to market. In 1899 the ground material was quoted at $2.00 a
ton in New York. In Michigan the average price of crude material
has been some $1.25 a ton, and for calcined plaster (plaster of Paris)
$3.00 to $5.00 a ton. During 1908 the domestic production of
crude gypsum amounted to 1,721,289, tons, valued at $4,138,560.
3. CELESTITE.
Composition. — Sulphate of strontium, SrSO„=sulphur trioxide,
43.6 per cent; strontia, 56.4 per cent. Hardness, 3 to 3.5; specific
gravity, 3.99; color, white, often blubh, transparent to translucent.
Differs from the carbonate (strontianite) by being insoluble in acids,
but gives the characteristic red color to the blowpipe Same.
According to Dana the mineral occurs usually associated with
limestones or sandstones of Silurian or Devonian, Jurassic, and
other geological formations, occasionally with metalliferous ores. It
also occurs in beds of rock salt, gypsum, and clay, and is abundantly
' See Mineral Statistics of Michipn, iSSi, for details of plaster work of that State.
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344 THE NON-METALLIC MINERALS.
associated with the sulphur deposits of Sicily. The principal locali-
ties in the United States are in the limestones of Drummond Island,
I-ake Huron; Put-in- Bay, Lake Erie; Kingston, Ontario, in crystal-
line masses, and in radiating fibrous masses in the Laurentian forma-
tions about Renfrew. Large crystals of a red color are also found
in Brown County, Kansas, and at Lampasas and near Austin,
Texas. Near Bells Mills, Blair County, Pennsylvania, the mineral
occurs in lens-shaped masses between the bottommost beds of the
Lower Helderberg limestone. On South Bass Island, in Put-in-
Bay, Lake Erie, the mineral occurs frequently in the form of beautiful
crystals of all sizes up to loo pounds in weight, transparent to trans-
lucent, and sometimes of a fine blue color, lining the walls and floor
of limestone caverns.
The Texas celestite is described^ as occurring in rounded Cavities
varying in size up to i8 inches in diameter in certain zones of Creta-
ceous limestone. The cavities are sometimes fairly well filled by the
mineral, but in most instances a portion has been removed in solu-
tion by percolating waters. It is estimated that the average amount
of the celestite in the limestone does not exceed 5 per cent.
Uses. — Celestite is used in the preparation of nitrate of strontia
employed in fireworks, its value for this purpose being due to the
fine crimson color it imparts to the fiame. Other strontium salts,
prepared either from celestite or strontianite, are used in refining
beet sugar. Small quantities are utilized in medicine. The demand
for the material is very small, and the annual product in the United
States limited to 40 tons in 1901.
4. HIBABILITE ; GLAUBES SALT.
This is a hydrous sodium sulphate, Na^Oj+ioHjO, =sulphur
trioxide, 24.8 per cent; soda, 19.3 per cent; water, 55.9 per cent.
In its pure state white, transparent to opaque; hardness, 1.5 to 2;
specific gravity, 1.48. Readily soluble in water, taste cool, then
saline and bitter.
Occurrence. — Aside from its occurrence in soda lakes associated
with other salts as described later this sulphate is of common occur-
• F. L. Hess, Engineering and Mining Journal, June 17, 1909.
ovGoc^lc
SULPHATES.
345
rence as an efflorescence on limestones, and in protected places, as
in Mammoth Cave, Kentucky, may accumulate in considerable
quantities, though not sufficient to be of economic value. Salt Lake,
Utah, contains a proportionately large amount of this sulphate,
which during the winter months is precipitated to the bottom, whence
it is not infrequently thrown upon the shore by waves.
According to Prof. J. E. Talmage,* when the temperature
falls to a certain point, the lake water assumes an opalescent appear-
ance from the separation of the sulphate. This sinks as a crystalline
precipitate and much is carried by the waves upon the beach and
there deposited. Under favorable circumstances the shores become
covered to a depth of several feet with crystallized mirabilite. The
substance must be gathered, if at all, soon after the deposit first
appears; as, if the water once rises above the critical temperature,
the whole deposit is taken again into solution. This change is veiy
rapid, a single day being oftentimes sufficient to effect the entire
disappearance of all the deposit within reach of the waves. Warned
by these circumstances, the collectors heap the substance on the
shores above the lap of the waters, in which situation it is compara-
tively secure until needed. To a slight depth the mirabilite efflo-
resces, but within the piles the hydrous crystalline condition is main-
tained. The sulphate thus lavishly supplied is of a fair degree
of purity, as will be seen from the following analyses of two samples
taken from opposite shores of the lake:
Percent.
Percent.
55-070
43.060
0,699
0.407
o.oas
0.700
S5760
0.63,
0.756
Sodium sulphate (Na^O,)
Sodium rhioride (NaCI)
Calcium sulphate (CaSO.)
99.961
99-757
Some 14 miles southwest of Laramie, in Albany County, Wyo-
ming, there exist deposits of sulphate of soda, such as are locally
' Sdence, XIV, 1SS9, p. 446.
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34*
THE NON-METAUIC M!NER4tS.
known as "lakes." The de[>osits in question comprise three of these
lakes lying within a stone's throw of one another. They have a
total area of about 65 acres, the local names of the three being the
Big Lake, the Track Lake, and the Red Lake. Being the property
of the Union Pacific Railroad Company, they are generally known
as the Union Pacific Lakes.
In ttese lakes the sulphate occurs in two bodies or layers. The
lower part, constituting the great bulk of the deposit, is a mass of
crystals of a faint greenish color mixed with a considerable amount
of black, slimy mud. It is known as the "solid soda," of which an
analysis is given below.'
c.-.™
Anhy.
''^St
J6.00
1-4S
0.77
8:. 63
1.S2
1.64
N^;:::;:::::;;:::;::::::
38-43
;i:s
9Q.I6
Total chloride calculoled as NaCl equals 1.16 per cent. This, calculated on 100
parts anhydrous Na,SO„ equals 3.12 per cent NaCI.
This solid soda is stated to have a depth of some 20 or 30 feet.
Above this occurs a superficial layer of pure white crystallized
material. This is formed by solution m water of the upper part of
the lower bed, the crystak being deposited by evaporation or cool-
ing. A litde rain in the spring and autumn furnishes thb water,
as do also innumerable small, sluggishly flowing springs present
in all the lakes. On account or the aridity of the r^on the surface
is generally dry, or nearly so, and in midsummer the white clouds
of efflorescent sulphate that are whirled up by the ever-blowing
winds can be seen for miles. Even when there is a little water present
there is no ditliculty in gathering the crystals by the train load.
The layer of thb white sulphate b from 3 to 12 inches in thickness.
When the crystals are removed the part laid bare b soon replenbhed
by a new crop.
The following b an analysis of the purest of the white sulphate
of soda, calculated upon an anhydrous basb:
' Jour. Franklin Inst., 1S93, p. 51.
jvGooi^lc
Pot Cent.
Trace.
i^^*:::::::;;::::;:::;::;:::::::::
Insoluble
99.99
Below is given an analysis of the water of the Track lake:
Density =i4j Tw, ( = 1,0725 specific gravity). Ten cubic
centimeters contain:
ConstituenU.
Na^.
CaSO,
MgSO, .-
MgCI,
Na,B,0,
Toul solids
Total solids by evaporation .
lamt. Per Cat.
0-7563- 9»
0.030a- 3.
Other soda deposits occur in Carbon and Natrona counties, and
still others are reported in Fremont, Johnson, and Sweetwater
counties.
It has been stated* that glauber salts has been found on the bot-
tom of Bay of Kara Bougas, an inlet of the Caspian Sea, in deposits
sometimes a foot in thickness.
5. GLAUBEKITE.
Composition. — Sodium and calcium sulphate. NasSO^-CaSO*, =
sulphur trioxide, 57.6 per cent; lime, 20.1 per cent; soda, 22.3 per
cent. This is a pale yellow to gray salt, partially soluble in water
— leaving a white residue of sulphate of lime — and with a slightly
saline taste. On long exposure to moisture it fails to pieces, and
hence is to be found only in protected places or arid areas. It occurs
associated with other sulphates and carbonates, as with thmardite
' ED^neering and Mining Jourpal, LXV, 1898, p. 310.
i,v Google
348 THE NON-METALLIC MINERALS.
and rairabilite at Borax Lake, in San Bernardino County, Cajifomia,
and with rock salt at Stassfurt and other European localities.
6. THENAaDIlE.
ComposUion. — Anhydrous sodium sulphate. Na2S0i,=sulphur
trioxide, 43.7 per cent; soda, 56.3 per cent. Color when pure, white,
translucent to transparent; hardness, 2 to 3; specific gravity, 2.68;
brittle. In cruciform twins or short prismatic forms roughly striated.
Readily soluble in water. Is found in various arid countries, as on
the Rio Verde in Arizona, at Borax Lake, California, and Rhodes
Marsh in Nevada, associated with other salts of sodium and boron.
7. EPSOMITE; EP30U SALTS.
Composition. — Sulphate of magnesia MgS0j+7H,0, = sulphur
trioxide, 32.5 per cent; magnesia, 16.3 per cent; water, 51.2 per
cent,
This is a soft white or colorless mineral readily soluble in water
and with a bitter saline taste. It is a constant ingredient of sea
water and of most mineral waters as well. Being readily soluble it
is rarely met with in nature except as an efflorescence in mines and
caves. In the dry parts of the limestone caverns of Kentucky, Ten-
nessee, and Indiana it occurs in the form of straight acicular needles
in the dirt of the floor, and in peculiar recurved fibrous and columnar
forms or in loose snow-white masses on the roofs and walls. In all
these cases it is doubtless a product of sulphuric acid set free from
decompKising pyrites combining with the magnesia of the limestone.
It is stated that at the so-called "alum cave" in Sevier County,
Tennessee, masses of epsomite, very pure and nearly a cubic foot
in volume have been obtained. The material in all these cases is of
little value, the chief source of the commercial supply being that
obtained as a by-product during the manufacture by evaporation
of common salt (sodium chloride).
In Albany County, Wyoming, are several lakes, the largest of
which has an area of but some 90 acres, in which deposits of epsom
salts in compact, almost aiow-white aggregates of small acicular
crystals of a high degree of purity aie formed on a very large scale.
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SULPHATES.
349
According to W. C. Knight,^ the deposits are situated upon a
high plateau about three miles north of Rock Creek, and lie in a
huge, undrained depression that is deepest at its southern end, where
it is about two miles wide and lies a hundred feet or nure below
the level of the surrounding country. From this de^>est p>ortk>n a
rather broad, shallow valley extends to the northwest for several
miles and contains numerous small and a few larger deposits of sodium
and magnesium salts which have for a long time been tributary to
the large epsomite deposit of about 90 acres in extent occupying
the lowest basin. The deposits are often covered with water in
early spring or after a hard storm, but thb soon evaporates and
leaves them solid epsomite or an accumulation of mud, sand, and
epsomite, the depth of which has been found by digging to exceed
Xexi feet.
Knight regards the salts as having been derived by leaching
from the decomposing Triassic or Permian red sandstones whk:h
prevail m the vicinity. Both epsomite and mirabilite occur in the
rocks and in the process are separated from one another by a natural
method of difTerential crystallization, the epsomite being more
soluble, remaining longest in solution and being laid down at a
greater dbtance from the original source.
The composition of the deposits b shown in the accompanying
analyses. No. i being takra from near the head of the gulch, and
No. 6 from the large deposit at the greatest distance from the source,
the others from intermediate points:
ConatiLuenta.
No. 1.
No..
No, 3.
Ho.*.
No.,.
No. 6.
4.16
95-54
5-«)
i.Sg
50-90
47-74
1.86
SO. 16
39-18
59.81
15-fii
5.«8
70. It
8. For description of Polyhalite, Kainite, and Kieseeite,
see under Halite, p. 43.
' Engineering and Mining Journal, February 14, 1903.
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THE NON-METALLIC MINERALS.
9. ALUU5.
Under this head are included a variety of minerals consisting
essentially of hydrous sulphates of aluminum or iron, with or with-
out the alkalies, and which are not always readily distinguished
from one another but by quantitative analyses. The principal varie-
ties are kalinite, tschermigite, mendozite, pickeringite, apjohnitc,
halotrichite, and alunogen. Aluminite and alunite are closely
related chemical compounds, but differ in hardness and general
physical qualities and in being insoluble except in acids.
Although possible sources of alum, none of these minerals have
been to any extent utilized in the United States, owing to a lack
of quantity or inaccessibility, the main source of the alum of commerce
being cryolite, bauxite, and clay, as elsewhere noted.
Kalinite is a native potash alum; composition K^0j.Al,(S04),H-
24HjO, = sulphur trioxide, 33.7 per cent; alumina, io.8 per cent;
potash, 9.9 per cent; water, 45.6 per cent, or, otherwise expressed,
potassium sulphate, 18.1 per cent; aluminum sulphate, 36.3 per
cent; water, 45.6 per cent. Hardness, 2 to 2.5; specific gravity,
1.75. This in its pure state is a colorless or white transparent
mineral, crystallizing in the isometric system, readily soluble in
water, and characterized by a strong astringent taste. In nature
it occurs as a volcanic sublimation product, or as a secondary mineral
due to the reaction of sulphuric acid set free by decomposing iron
pyrites upon aluminous shales. Its common mode of occurrence is,
therefore, in volcanic vents or as an efflorescence upon pyritiferous
and aluminous rocks. Being so readily s-^luble, it is to be found in
appreciable amounts in humid regions only where protected from
the rains, as in caves and other sheltered places. So far as known
to the author, the mineral is nowhere found native in such quantities
as to have any great commercial value.
Tschermigite is an ammonia alum of the composition
(NH4),SO<.Al,(S04),-|-24H,0,-aluminum sulphate, 37.7 per cent;
ammonium sulphate, i4.6percent; water, 47.7 per cent. Sofaras
ov Google
SULPHATES. 3SI
reported this salt has been found only at Tschermig and in a
mine near Dux, Bohenriia. It is obtained artificially from the
waste of gas works. Mendozite is a soda alum of the composition
NajSO,.Ali(SO(),+ 24HiO, = sodium sulphate, 15.5 percent; alumm-
um sulphate, 37.3 per cent; water, 47.2 per cent. The mineral closely
resembles ordinary alum, and has been reported from Mendoza, in
the Argentine Republic, hence the name. Pickeringite is a mag-
nesium alum of the composition MgSO<.Al,(S04),+ 23H,0, = alu-
minum sulphate, 39.9 per cent; magnesium sulphate, 14 per cent;
water, 46.1 per cent. The mineral is of a white, yellowish, or
sometimes faintly reddish color, of a bitter, astringent taste, and occurs
in acicular crystals or fibrous masses. Halotrichite has the composi-
tion FeSO,.Alj(S04)j-|-24H,0, = aluminum sulphate, 36.9 per cent;
ferrous sulphate, 16.4 per cent; water, 46,7 per cent. The mineral
is of a white or yellowish color, and of a silky, fibrous structure,
hence the name from the Greek word aXs, salt, and SfiiS, a hair.
Apjohnite has the fonnula MnSO,.AljCSO(),-|-a4HjO, = manganese
sulphate, 16,3 per cent; aluminum sulphate, 37 per cent; water, 46.7
per cent. It occurs in silky or asbestiform masses of a white or yel-
lowish color, and tastes like ordinary alum. It has been found in
considerable quantities in the so-called "Alum cave" of Sevier
County, Tennessee. According to Safford: '
"This is an open place under a shelving rock, . . . The slates
around and above this contain much pyrites, in fine particles and
even in rough layers. . . ■ The salts are formed above and are
brought down by trickling streams of water. . . . Fine cabinet
specimens could be obtauied, white and pure, a cubic foot in
volume."
Dana states that the cave is situated at the headwaters of the
Little Pigeon, a tributary of the Tennessee River, and that it is prop-
erly an overhanging cliff 80 or 100 feet high and 300 feet long, under
which the alum has collected. It occurs, according to this authority,
in masses, showing in the cavities fine transparent needles with a
silky luster, of a white or faint rose tinge, pale green or yellow.
' Geology of Tennessee, 1869, p. 197.
J, Google
3Sa THE NON-METALLIC MINERALS.
Epsomite and melanterite occur with it. AluiK^n has the compo-
sition Al,{SO|),+ i8H20, = sulphur trioxide, 36 per cent; alumina,
15.3 per cent; water, 48.7 per cent; hardness, 1.5 to 2; specific
gravity, 1.6 to 1.8. This is a soft white mineral of a vitreous or
silky luster, soluble in water, and with a taste like that of the common
alum of the drug stores. It occurs in nature both as a product
of sublimation in volcanic regions, and as a decomposition product
Fig. 51. — Sbeich Map ot Gila River Alum Deposits.
[U. S. Geological Survey-l
from iron pyrites (iron disulphide) in the presence of aluminous
shales. So far as the present writer is aware, the native product
has no commercial value, being found (on account of its ready
solubility) in too sparing quantities in the humid East, while the
known deposits in the arid regions are remote and practically inac-
ov Google
SULPHATES.
355
A white, fibrous variety is stated by Dana to occur in large
quantities at Smoky Mountain, in North Carolina, and large quan-
tities of an impure variety, often of a yellowish cast, are found in
Grant County, en the Gila River, about 40 miles north of Silver
City, New Mexico. The mineral is also found in Crooke and
Fremont counties, Wyoming; in Schemnitz, Hungary, and in
Japan.
The Gila deposits occupy a somewhat circular area — ^what is in
fact the cracter of an extinct volcano. The country rock is basalt,
while the rock which carries and also gave rise to the deposits is
an andesitic breccia, now h^ly altered by solfataric actk>n. The
alum salts — which have undoubtedly originated throu^ the actbn
of acid solfataric waters on the porous breccia, are found in the
form of incrustations wherever the conditions have been favorable
to their formation and preservation. The original salt would appear
to have been mainly halotrichite, but in many instances this has
been dissolved by surface waters, when the iron separates out as an
insoluble oride and on evaporation the salt is deposited in the iron-
free condition, alunogen. The following analyses * show the com-
position of selected samples of these salts from this locality:
HALOTStCBITE, GILA B
c™,.,u™,..
A
B
C
7-94
11.77
35 -'S
45.09
I3-S9
7.77
37-19
40.63
0.50
so"!::.;:;:;::;::::::;:;::::::::::;:
34-S
46.7
hZ .:....;
100.05
99- "7
100. oo
C. Ttanntical
at halotrichit*.
' Builelin No. 313, U. S. Geological Survey, p. tto.
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THE NON-METALUC MINERALS.
Const
..™u.
A
•
c
16.19
3fi.93
...."■«...
4S.1
SO, :
9?.'7
■oo.,3
A. Cuefully idecud crytuli.
B. PinkiihcnuU.
The upper portion of the deposit has naturally been leached of
all or a considerable proportion of its soluble salts by surface
waters. Though no borings have been made it is thought that the
deeper-lying portions contain an almost unlimited supply. It was
at &rst reported^ that the residual rock from which the sulphates had
been leached consisted essentially of bauxite, and it was so stated
in the Erst edition of this work (p. 341). Subsequent investigation
has, however, shown this to be an error.
In New South Wales alunogen is commonly met with as an efflo-
rescence in caves and under sheltered ledges of the Coal Measure
sandstone, usually with epsomite, as at Dabee, County Phillip;
Wallerawang and Mu<^ee road, County Cook; the mouth of the
Shoalhaven River, and other places. It is also found in the crevices
of a blue slate at Alum Creek, and at the Gibraltar Rock, County
Argyle, and occurs as a deposit, with various other salts, from vol-
canic vents at Mount Wingen, County Brisbane, together with
native sulphur in small quantities; and at Appin, Bulli, and Pitt
Water, County Cumberland; Cullen Bullen, in the Turon district,
County Roxburgh; Tarcutta, County Wynyard; Manero; Wingello
Siding, and Capertee.
A specimen in the form of fibrous masses, made up of long, acicular
crystab of a white, silky luster, Uke satin spar, found as an efSores-
cence in a sandstone cave near Wallerawang, was found to have the
following composition:
' TmDsaclions American Institute of Miniog Engineera, XXIV, 1S94, p. 573.
ov Google
Percent.
IS
34
635
Ml
337
Soc&
■«™ i
1
Alnminite. — Aluminite is a dull, lusterless, earthy aluminum sul-
phate of the composition indicated by the formula A1,0,.S0,,9H,0,
= sulphur trioxide, 23.3 per cent; alumina, 29.6 per cent; water,
47.1 per cent. It is soluble only in acids, white in color, opaque,
and occurs mainly in beds of Tertiary and more recent days.
Alunite.— Composition KsO.3Al,0j.4SO„6HjO, = sulphur triox-
ide, 38,6 per cent; alumina, 37.0 per cent; potash, 11.4 per cent;
water, 13.0 per cent. Hardness, 3.5 to 4; specific gravity, 2.58 to 3.75.
This mineral occurs native in the form of a fibrous, or compact,
finely granular rock of a dull luster somewhat resembling certain
varieties of aluminous limestones. It is infusible, and soluble only
in sulphuric acid. The more compact varieties are so hard and
tough as to be used for millstones in Hungary. No deposits of such
extent as to be of economic importance are Icnown wiUiin the limits
of the United States. Alunite as an alteration product of rhyolite
has been described by ^^'hitman Cross • as occurring at the Rosita
Hills in Colorado, the alteration being brought about through the
influence of sulphurous vapors incident to the volcanic outbursts.
The altered rhyolite as shown by analyses had the foUowingcompo-
sition: Silica, 65.94 per cent; alumina, 12.95 per cent; potash, 2.32
percent; soda, 1.19 per cent; sulphur trioxide, 12.47 percent; water,
4.47 per cent; FeaOs, etc., 0.55 per cent. This indicates that the
rock is made up of alunite and quartz, in the proportion of about
one-third of the former to two-thirds of the latter. Ransome men-
tions the alteration of the feldspar labradorite into alunite and
' American Joucnat uf Sctence, XLT, 1891, p. 468.
J, Google
35* THE NON-METALLiC MINERALS.
quartz in the dacites of Goldfield, Nevada, the alteration being
brought about through the action of sulphuric acid. The most
noted occurrences of alunite are at Tolfa, near Rome, and Montioni,
in Tuscany, Italy; Musaz, in Hungary; on the islands of Milo,
Argentiera, and Nevis, in the Grecian Archipelago; Mount Dor^,
in France, and at Bullah-Delah, in New South Wales. The BuUah-
Delah deposit is regarded by Pittman ' as probably one of the most
remarkable in the world. It occurs in the form of a narrow, anti-
clinal mountain range, some three miles in length and with a maxi-
mum height of 900 feet, which for nearly one-third its total length
Fig. 53, — Sectiun across Bullah-Delah Mountain, showing alunite beds.
[After PitlQian, Mineral Resources of New South Wales.]
is made up almost wholly of alunite of varying degrees of purity.
The core of the range (see Fig. 52) is of rhyolite, and is flanked on
either side by sandstone. " A large, almost perpendicular crown
of alunite, 400 feet high, occupies the center, while at intervals along
the backbone of the ridge, to the north and south, are other pro-
jecting crags of the same material but of lesser height. . . . Between
the projecting crags are saddles which are occupied by dykes of
dolerite trending across the range. Naturally a comparatively
small part of thb enormous mass of material is sufficiently pure to
bear minmg and transportation. Four varieties are recognized,
(i) a light pink, containing 1.7 per cent silica; (2) a chalk-white
containing 16.4 per cent silica; (3) a purple containing 19.5 per cent
silica, and (4) a granular variet}' containing 39.5 per cent sQica.
' Mineral Resources of New South Wales, 1901, p. 415.
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SULPHATES.
357
At present only that carrying less than lo per cent of silica is
worked.
Here, as in the cases above mentioned, the alunite is regarded
as an alteration product of rhyolite, the agmts of alteration being
sulphurous fumes foUowing the intrusion of dolerite.
DeLauney regards the Tolfa, Italy, alunite as a product of
superficial alteration of the pyritized portions of a trachyte, the
products of decomposition being kaolin or alunite, according to
the presence or absence of a sufficient amount of pyrite to yield the
necessary sulphuric acid. That alunite is a. less common product
of feldspathic decomposition than kalinite is due to the sfiecial
condition of pressure and temperature requisite for the formation
of the first-named mineral^
Alunite from the mines at Tolfa varies considerably in composi-
tion. The crystallized variety contains about 32 per cent alumina,
whereas the cruder specimens which contain a large quantity of silica
have only about 17.5 per cent The following is an analysis of an
average sample:^
Con.Up«nt..
Percent.
29.74
7-SS
11.10
31.71
poish™. .;"'; :"':
.00.00
Alum Slate or Shale is a name given to fine-grained arena-
ceous rocks of variable composition, but consisting essratially of
siliceous and feldspathic sands and clays with disseminated iron
pyrites. The following analyses from Bischof's Chemical CSeology
will serve to show their varying nature:
' La Metallogeale de I'ltalle, p. 137.
* Journal of the Societ]' of ChEmicat Industry, I, 1SS3, p. 5^:,
ov Google
THE NON-METALLIC MINERMLS.
CotMrttuenU.
I.
II.
III.
65-44
14.87
1-05
■■S
'J4
4..SQ
.48
i-iS
Undet.
7JJ0
16.45
50-13
'0-73
j-27
^0
■'7
1.48
S.o3
Undet.
7-S3
Carbon and water
(1) An alum slate from Opsloe, near Christiaaia, Norway, (II) from Bornholm,
and (ni) from Gamsdorf, near Saalfetd, Prussia.
Concerning No. Ill it is stated that on the roof of the adit, driven
into the slate, there are almost eveiywhere yellow or white opaque
stalactites, and more rarely a green transparent deposit is produced-
Both consist of hydrated basic sulphate of alumina and perozideof
iron. In the former, iron predominates; in the latter, alumina.
Both substances are quite insoluble in water.
From shales and slates of this type the alum b obtained by
allowing the crushed material to undergo proloi^ed weathering or
a roasting process. The essential part of the reaction consists in
oxidizing the bisulphide to the condition of a sulphate and finally
into iron sesquioxide, with separation of free sulphuric acid, which
attacks the alumina, forming an equivalent quantity of sulphate of
aluminum. So far as is known this process is not now carried on
in the United States.
The alum shale of the English Upper Liassic formation consists
of hard blue shale with cement stones. On exposure to the air it
gradually becomes incrusted with sulphur, and occasionally with
alum.
In composition the alum shale is as shown in table on page
359-
From this shale potash-alum was formerly made near Whitby
and Redcar, the aluminum sulphate being extracted from the shale,
and the potash-salt being added. The trade, which since the days
of Queen Elizabeth has been largely carried on, has now almost
passed away, as alum is now manufactured in other places from coal
shale.
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HYDROCARBON COMPOUNDS.
ConiticueaU.
PvCoac
8.S0
18.30
a. IS
0.90
1.50
Tr»ce.
Trace.
8.39
9.00
^5Upn«« ........................
FoUsh
99.91
Xni. HYDROCARBON COMPOUNDS.
Under the name hydrocarbon compounds are included a varieQr
of substances differing at times widely in physical properties and
in the proportional amounts of their main constituents, but alike in
being composed essentially of carbon and hydrogen. None of the
series crystallize in nature, and as a rule the chemical composition
is so variable as to render futile all attempts at classification on a
mineralogical basis. In practice it is customary to divide them
into two mam groups, (i) The Coal Series, (2) The Bitxunen
Series.
I. THE COAL SERIES.
Here are included a variety of more or less oxidized hydrocarbons,
differing considerably in their physical properties and in chemical
composition, but alike in that they have originated through the
accumulation and decomposition of plant debris largely out of
reach of the oxidizing influence of the air. As to the method of this
accumulation there has from time to time been more or less discussion.
ovGoO'^lc
36o THE NON'METALUC MINERALS.
By many the coal beds are r^arded as havmg resulted from the
gradual accumulation, in place, of organic matter growiog on gradu-
ally subsiding marshes, or marshes and swamps subject to periodic
overflow, the materiaj itself being largely in the nature of sphagnous
mosses. By others it is thought that the plant material was first
transported by running streams and laid down on the bottoms of
deltas and lagoons; that the coal beds are, in short, as true sedimen-
tary deposits as the shales and sandstones with which they are
associated. This last view, though not generally accepted, would
seemingly best account for the constant interlamination of the coaly
and sandy or clayey material and the marked stratification of the
coal itself. Moreover, it would explain the almost completely
structureless nature of many coals, since calcium sulphate, one of
the constituents of sea water, tends K> decompose organic matter,
reducing it to a pulp-like and at times almost mucilaginous con-
dition.
According to the amount of change that has taken place in the
original plant material, the amount of volatile matter still retained
by it, its hardness and burning qualities, several varieties of coal
are recognized, which are described somewhat in detail below. The
general subject, it may be said, is far too large to be satisfactorUy
disposed of here, and the reader is referred to the special works
noted in the bibliography.
Peat. — This name is given to a material resulting from fce accu-
mulation of plant remains, largely of the nature of sphagnous mosses,
in bogs, and which has, as a rule, undergone so slight modification
that the plant fibers are still readily recognizable, though where the
beds have reached a considerable thickness the lower portion may
be reduced to a dense brownish-black mass somewhat resembling
true coal. These deposits as existing to-day are all of recent origin,
and to be found only in humid and temperate or north temperate
climates. They are developed to an enormous extent in Ireland,
where they average, in some cases, twenty-five feet in thickness..
They are also abundant on the continent of Europe and throughout
^e northern and eastern United States. In Ireland and on the
Continent &ie material has been extensively used as fuel, in the
first-named country largely in its native state, but in Germany
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i^I" i l-^^J
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Diq.izeobvl^OOQle
HYDROCARBON COMPOUNDS.
361
after being made up into briquettes.' Tlie material, it should be
noted, rarely occurs in such form as to be immediately available
for fuel, the chief drawbacks being the large amount of water
it contains and its loosely compacted nature. Recourse must there-
fore be had to artificial drying and compression. Ordmarily fresh
peat, as taken from the bog, will contain from 75 per cent to even
90 per cent of moisture. By compression, as in briquette manu-
facture, it is reduced to about one-fourth its original bulk, i.e., 4
cubic feet of fresh will yield i cubic foot of the compressed material.
The analyses given below are calculated on a water-free basis.
Ordinary air-dried peat will contain about 20 per cent of moisture.
The analyses are selected out of a large number simply to show
averages. No. i is of material from Penobscot County, Maine; No.
2 from near Ottawa, Canada:
Vegetable, combustible matlei
Fired carbon
Ash
Nitrogen
67-S7
7.18
Cheapness of wood and coal has caused peat to be largely dis-
regarded in America, but recent events have turned attention toward
it once more, and it seems probable that within a few years numerous
plants will be established for converting the crude material into a
satisfactory form for burning.
The rate of growth of peat, or otherwise expressed, the rate of
accumulation of coal-bed material, has been a matter of frequent
observation. Naturally it is widely variable for different localities.
be handled very cheaply. In this process the peat is first reduced [o a hne paste
and leaves the machine in a continuous thick tube 3 lo s inches in diameter, and
Is Ihen cut off in sticks and dried for three days on wooden supports and for a longer
period in the air on wire netling. After lirenty-five days the aticki become dry and
hard and may be bumed as fuel; but it is more profitable to convert these slicks into
charcoal. This ia accomplished in sii hours in a retort, and 3 tons of peat make
I ton of charcoal. — Engineering and Mining Journal, LXV, Februaiy a6, 1898, p. 348.
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36a THE NON-METALLIC MINERALS.
G. H. Ashley has calculated ' that a fair average maximum of peat
growth is at the rate of one foot in ten years. But one foot of the
spongy material at the surface will, owing to pressure and loss
through decomposition, shrink to a little over an inch, and it is
probable that one foot a century would more nearly represent the
rate of accumulation of the dense, compact material found in the
deeper part of bogs. This material, even were there no further
loss through decomposition, would suffer a reduction in mass of
fully two-thirds in passing into the condition of ordinary bituminous
coal. On this basis it would require 300 years for the accumulation
■of material to form one foot of coal, or 2,100 years to form the seven-
foot Pittsburg bed, and probably 100,000 years, in round numbers,
-for the total approximate 300 feet of the entire Appalachian coal fields.
Lignite or Brown Coal. — This name is given to a brownish-
black variety of coal characterized by a brilliant luster, conchoidal
fracture, and brown streak. Such contain from 55 to 65 per cent of
carbon, and bum easily, with a smoky flame, but are inferior to the
true coals for heating purposes. They are abo objectionable on
account of the soot they create, and their rapid disintegration and
general deterioration when exposed to the air. They occur in beds
under conditions similar to the true coals, but are of more recent
origin. The lignitic coals of the regions of the United States west
of the Mississippi River are mainly of Laramie age, and often show
easily recognizable traces of their organic origin, such as (impressed
and flattened stems and trunks of trees with traces of woody
fiber.
Jet is a resinous, coal-black variety of lignite sufficiently dense to
be carved into small ornaments. According to Professor Phillips,
it is simply a coniferous wood, and still shows the characteristic
structure under the microscope. It has been known since early
British times, having at first been found on the seashore at Whitby
and other places. The largest piece on record was obtained from
the North Bats, near Whitby. It weighed some 5,180 pounds and
was valued at about $1,250. The material is now regularly mined
both in the cliffs and inland, and is one of the most valuable prod-
ucts of the Yorkshire coast.'
' Economic Geology, II, 190;, p. 46.
• Geologjr of England and Wales, p. 378.
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Fig. 1. — Typical Moss or Peat Bog near Augusta, MaIrc.
[.■Uter E. S. Bastin, Bulletin No. 376, U. S. Geological Surrey.]
3.— Section of a Peat Bog, near Mias, Ri
[From a photograph by A. M. Miller.]
PLATE XXXIII.
[Facing page 362.] n^lc
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HYDROCARBON COMPOUNDS. 363
Bitnminoas Coals.— Under this name are included a series of
compact and brittle products in which no traces of organic remains
are to be seen on casual inspection, but which under the microscope
often show traces of woody fiber, spores of lycopods, etc. These
coals are usually of a brown to black color, with a brown or gray-
brown streak, breaking with a cubical or conchoidal fracture, and
burning readily with a yellow, smoky flame. They contain from 35
to 75 per cent of fixed carbon, 18 to 60 per cent of volatile matter,
from 2 to 20 per ceat of water, and only too frequently show traces
of sulphur, due to included iron pyrites. Several varieties of bitu-
minous coab are recognized, the distinctions being based upon their
manner of burning. Coking coals are so called from the facility with
which they may be made to yield coke. Such give a yellow fiame in
burning and make a hot fire.- Other varieties of apparently the same
composition and general physical properties can not be made to yield
coke, and are known as non-coking coals. Cannel coal has a very
compact structure, breaks with a conchoidal fracture, has a dull luster,
ignites easily, and bums with a yellow fiame. It does not coke. Its
chief characteristic is the lai^e amount of volatile matter given off
when heated, whereby it is rendered of particular value for making
gas. Before the discovery of petroleum it was used for the distilla-
tion of oils. Below is given the composition of (I) a coking coal from
the Connellsville Basin of Pennsylvania, and (II) a cannel coal from
Kanawha County, West Vi^inia,
I.
II.
39.885
'■339
5».oo
I3-SO
iS.s"
99-978
100.00
Torbanite.— The name torbanite, boghead mineral and kerosene
shale have been variously given to a tough brownish-black to coal-
black, lusterless substance, breaking with a. conchoidal fracture
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364 THE NON-METALUC MINERjILS.
and somewhat resembling cannel coal, which is found in both the
upper and LowerCoal measures of New South Wales, Australia, and
near the base of the Carboniferous near Bathgate, in Liolithgow-
shire, in Scotland. It occurs, according to E. F. Pittman,* in lentic-
ular areas or patches passing at the edges into bituminous or splint
coal or grading into carbonaceous shale. The beds are but a few
feet in thickness and the largest deposit known not over a mile in
length. It b regarded by different authorities as due to the accu-
mulation in lakes of vegetable material, either sporangia or algae,
and is therefore classed with the coals.
The New South Wales torbanite contains from 70 to 80 pa* cent
of volatile hydrocarbons; 6 to 8 per cent of fixed carbon, and 7 to
20 per cent of ash. It has in times past be«i used mainly for gas
and oil making, by a process of distillation. The best qualities,
yielding from 150 to 160 gallons of oil to the ton or about 20,000 feet
of gas of 48 candle intensity.^
Anthracite Coal. — I'his is a deep-black, lustrous, hard and
brittle variety, and represents the nio.^t highly metamorphosed
variety of the coal series. Traces of organic nature are almost
entirely lacking in the matter of the anthracite itself, though impres-
sions of ferns, lycopxxis, sigillaria, and other coal-forming plants are
frequently associated with the beds in such a manner as to leave
little doubt as to their origin. .Anthracite is ignited with difficulty
and bums with little flame, but makes a hot fire. Below is given
the average composition of a coal from the Kohinoor Colliery,
Shenandoah, Pennsylvania.'
PerCait.
3.163
3.717
8..MJ
Xsh :"'::':::::'::'"
'■»■»»
' Mineral Resources of New South Wales, p. 35S.
' A. Liversidge, Mineiata o( New South Wales, p. 145.
' F. P. Dewe;, Bulletin No. 41, United States National Museum, 1
Diqmzec by Google
Fig. I. — Quarry o( Bituminous Sandstone, Oklahoma.
PLATE XXXIV.
[After G. H. Eldridge, U. S. Geological Survey.]
lF^cin,i! pan>: .i^njGoO'^lc
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HYDROCARBON COMPOUNDS. 365
Until recently it has been quite generally assumed that anthracite
is but jk bituminous coal from which a large portion of the volatile
matter has been driven off by the heat and pressure incidental to
mountain making or the intrusion of igneous rocks. Undoubtedly
anthracite may be thus produced and in some cases has been
thus produced, as in the Cerrillos coal field of New Mexico,
where a bituminous coal containing some 30 per cent of volatile
matter has been locally converted into anthracite through the intru-
sion of a mass of an andesitic trachyte.
Prof. J. J. Stevenson has, however, argued ' that the difference
between anthracite and the bituminous coals is due, not to metamor-
phism through heat and pressure after being buried, but rather to
the former having been longer exposed to the percolating action. of
water, whereby the volatile constituents were removed, prior to its
final burial, and the consolidation of the inclosing rocks.
Like the other coals, anthracite occurs in true beds, but is con-
fined mostly to rocks of the Carboniferous Age. Thin seams of
anthracite sometimes occur in Devonian and Silurian rocks, but
which are too small to be of economic value. Rarely coals .
of more recent geological horizon have been formed locally,
altered into anthracite by the heat of igneous rocks. Through
a still further metamorphism, whereby it loses all its volatile con-
stituents, coal may pass over into graphite. (See p. 71.)
The principal anthracite coal regions of the United States are in
eastern Pennsylvania. From here westward throughout the interior
States to the front range of the Rocky Mountains the coals are all
soft, bituminous coals. Those of the Rocky Mountain region proper
are largely lignitic, passing into the bituminous varieties. A small
field of anthracite exists, however, in Colorado, and recent discoveries
point to a larger one in .Alaska. (See Plate XXXII.)
' Bulletin Geological Society of America, VII, iS<)5, p. jaj.
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366 THE NON-MBTMUJC MINERALS.
BIBUOGRAPHY.
The bibliognphy of coal, even though limited lo the United States, would be
enonnous. Id all cases reference nhould t>e made to the publications of the various
State surveys, where such have existed. The few titles here given are of articles of
general interest, and, as a rule, not relating to the coals of one particular locality alone.
Waltkk R. Johnson, A Report lo the Navy Department of the United Slates on
American Coals Applicable to Steam Navigation and lo other purpo9<«.
Washington, D.C., 1844.
Richard Cowlinc Taylor. Statistics of Coal. The Geographical end Geological
Distribution ot Mineral Combustibles or Fossil Fuel, etc
Philadelphia, 1S48.
J. LeConte. Lectures on Coal.
Report of the Smithsonian Institution, 1857, p. 119.
r. H. LEAVni. Peat as n Fuel.
Second Edition. Boston, 1S66, p. 16S.
Facts About Peal ns an Arlicle of Fuel.
Third Edition. Boston, 1867, p. 316. ^
LzoLesquekf.ux. On the Formation of Lignite Beds of the Rocky Mountain RegioD.
American Journal ot Science, VII, 1874. p. lO-
I. S. Newbebrv. On the Lignites and Plant Beds of Western America.
American Journal of Science, VII, 1874, p. .jjg.
JahkS MacFarlane. Coal Regions of .America.
New York, 1875.
MlALL Green, Thorpe. Rucker, and Marshall. Coal; Its History and Uses.
Edited by Professor Thorpe. I^ndon, 1878, p. 3(13.
J. S. NEWBERsy. On the Physical Conditions under which Coal was Formed.
Science, I, March i, 18S3, p. 81).
Charles A. A^kburner. The Classification and Compodtion of Pennsylvania An-
thracites.
Transactions of the American Institute of Mining Engineers, XIV, 1885,
p. 7o«
Leo Lf^QOeredx. On the Vegetable Origin of Coal.
Annual Report of the Geological Survey of Pennsylvania, 1885, p. 95.
S. W. Johnson. Peat and its Uses as Fettiliicr and Fuel.
New York, 1886.
Graham MacFariane. Notes on American Cannel Coal.
Transactions of the American Institute of Mining Engineers, XVIII, 1890.
W. Galloway. The South African Coal Field.
Proceedings of the New South Wales Institute of Ei^ineers, No, 2, XVII, 18(10.
p. 67.
Levi W. Meyers. L'Origine de la Houille.
Revue de Quest. Sciemi6quc, Brussels, July, 1B91, pp. 5-47.
J. J. Stevenson. Origin of the Pennsylvania Anthracite.
Bulletin Geological Society of America, V, 1S94, pp. 39-70.
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HYDROCARBON COMPOUNDS. .167
M. L. LBMtBSB. Sur la Tranifbmtalian des V<g£uui eD Combustibles FoUiles.
VIII Congr^ Gfologique Iateniatbiu.1, 1900, ist Fasciucle, Planches i & XI,
p. 502.
Arthuk L. Paksonb. Peat (Its formalion, uses and ofcurreiice in New York).
New York State Museum, (3d Report of State Geologist, 1903, pp. iS-SS.
Makius R. Caupbell. The ClassiScalion of Coals.
Bi-Monthly Bulletin American Inslitue of Mining Engineers, No. 5, i90St
pp. 1033-1049.
C. W. Pabhelee and W. E. McCoukt. A Report on the Feat Deposits of Northem
New Jersey.
Annual Report of the Stale Geologist, 1905, Part V, p. 113.
HXNBY B. KcuMEL. Thc Fol Deposits of New Jersey.
Economic Geology, II, No. i, 1907, pp. 24-33.
G, H. Ashley. Tbe Maximum Rale of Deposition of CoaL
Economic Geology, II, 1907, pp. 34-47.
David White. Some Problems of the Formation of CoaL
E^nomic Geology, III, 1908, pp. 193-318,
The Effect ot Oiygen in Coal.
U. S. Geological Survey, Bullelin No. 382, 1909.
E. NvsisoH. Peat and Lignite. (Their Manufacture and Uses In Europe.)
Canada Dept. of Mine, Mines Branch, Ottawa, 1909.
Edson S. Bastin and Chakles A. Davis. Peal Deposits of Maine.
U. S. Geological Survey, Bulletin No. 37C, 1909.
Erik Nystbou and S. A. Akket. Invesli^lion of the Peat Bogs and Feal Industry
of Canada during the Season 1908-09.
Canada Dept. of Mines, Mines Branch, Bulletin No. i, 1909.
2. THE BITUlfEN SERIES.
Under this head are included a series of hydrocarbon compounds
varying in physical properties from solid to gaseous and in color from
coal-black through brown, greenbh, red, and yellow to colorless.
Unlike the members of the series already described, they are not the
residual products of plant decomposition in situ, but are rather, in
part at least, distillation products from deeply buried organic matter
of both animal and vegetable origin. The members of the series
differ so widely in their properties and uses that each must be dis-
cussed independently. The grouping of the various compounds as
given below is open to many objections from a strictly scientific stand-
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^6i THE NON-METALUC MINERALS.
point, but, all things considered, it seems best suited for the present
purposes.'
TABtnjLK a-ASSmCATION OF HYDKOCAKBONS.'
Gaseous Marsh gas (Natural gas).
Fluidal Petroleum (Naphtha).
1 Fittosphalt (Maltha).
Viscous and semisolid. . .
<:»»'™^) IKSS;.
Mineral ta
( Asphalt.
j Elaterite.
\ Wurtziilite.
1 Albertite.
i Grahamite.
( Uinuite,
f Succinite.
j Torbanile.
[ Ambrite.
Ozokerite.
TABULAK CLASSmCATIOIf O
Mixed with limestone, "aspbal-l Seyssel, Val de Travera, Lobsan, Uli-
tic limestone." ) nms, and other localities.
Mixed with silica and sand, ' ' as- j California, Kentucky, Utah, and otbef
phaltic sand." ) localities. " Bituminous ^ca."
"tmrSnL"'" """■ ""■) ™". <:•''-• ™«°™ "•^-
X,:, „;„ .. . L- , J Canada, California, Kentucky, Vireiou,
,15itumtaous sctusts ^ and other localities.
■ci -A i Tbicli oils from the distillation of petro-
^'"^ i leum. "Residuum."
,,. j Gas-tar.
. V""^"' 1 Pitch.
(Refined Trinidad asphaltic earth. Mas-
tic of asphaltite.
Gritted asphaltic mastic. Paving com-
pounds.
' See article What is Bitumen, hy S. F. Peckham, Journal of ths Fianklin Insti-
tute, CXL, 189s. PP- 370 to 383.
* W. F. Blake, Transactioits of the Americou Institute of Mining Enginecn, XVII^
1890, p. 581.
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HYDROCARBON COMPOUNDS.
Still aoother arrangement is that given below :
369
TABLE or OCCUWIENCE C
NATURAL BirnuBH.'
Important
bltumetu.
Natural lUphthiL Found in petroleum districts.
Petroleum Pennsylvania, Ohio, Wyoming, Cftli-
fomia, etc., in United Stateaj Runia,
etc.
Maltlu. CsUfoniiii,Wyo[nin)r,AUbBniB, Utah, Col-
orado, Kentucky, ^Te» Meilro, Ohio,
Texa.1, Indiiin Tcnilory, etc.; Russiii,
France, Gernwny, etc.
Noith America. .t'wh, California, Texas,
Central Ammca.CutMi, Meiico, etc.
South America . .Trinidad, Venezuela,
Peru, Colombia, eti:
Europe Caucasia, Svr»n-on-(be-
Volga, Oermany,
France, Italy, .Austria,
etc.
Asphaltum
North AmeiicH.
Aua...
Africa. .
etc.
.Oian in Egypt; piobaMj
other places.
.We«t Virmnia, Kentucky,
Texas, Wyoming, Utah,
Colorado, CaliFomia,
Oklahoma, Montana,
New McidcD.
». .Mexico, Cuba, etc.
.. .Trinidad, Veneiuela,
Peru, Colombia,
etc.
..Geimany. Switzerland,
France, Italy. Sicily,
Rutsia, Austria, Spain,
etc.
..Aua Minor, Palestine,
Ba([dad, and probablj
in China.
..Egypt, and probably else-
wheie in Africa.
Origin. — Of the many views, mainly theoretical^ that have been
put forward to account for the origin of bituminous compounds, but
two need be noted in detail here. Interested readers are referred to
the bibliography given on page 398, and particularly to the works of
' J, W, Howard, ai
CXL, 189s, p. 900.
quoted by S. P. Sadtler, Journal of the Franklin Inatltnt^
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37° THE NON-METMLUC MINERALS.
Peckham, Orton, and Redwood. F. W. Clarke's excellent sum-
mary ' is also to be read with* profit. Prof, Edward Orton, after
an exhaustive consideration of the occurrence of petroleum, natural
gas, and asphalt in Kentucky,^ gives the following precise summary:
*'i. Petroleum is derived from organic matter.
"2. Petroleum of the Pennsylvania type is derived from the
organic matter of bituminous shales, and is probably of vegetable
origin.
"3. Petroleum of the Canadian type is derived from limestones,
and is probably of animal origin.
"4. Petroleum has been produced at normal rock temperatures
(in American fields), and is not a production of destructive distilla-
tion of bituminous shales.
"5. The stock of petroleum in the rocks is already practical^
complete."
Hofer^ regards petroleum as of animal origin only, and ad-
vances the ailments given below in support of his theory:
"i. Oil is found in strata containing animal, but little or no
plant remains. This is the case in the Carpathians, and in the
limestone examined in Canada and the United States by Steny
Hunt.
" 3. The shales from which oil and paraffin were obtained in the
Ltassic oU shales of Swabia and of Steirdorf, in Styria, contained
animal, but no vegetable remains. Other shales, as, for instance,
the copper shales of Mansfield, where the bitumen amounts to 23
per cent, are rich in animal remains and practically free from v^e-
table remains.
"3. Rocks which are rich in vegetable remains are generally not
bituminous.
"4. Substances resembling petroleum are produced by the decom-
position of animal remains.*
' Data for Geochemistry Bulletin No. 330, U. S. Geobgical Survey, p. iii.
' Report on the Occurrence of Petroleum, etc., in Western Kentucky. Geolc^cal
Survey o£ Kentucky, John R. Proctor, director, 1891.
' As quoted by Redwood, I, p. 238.
' Dr. Engler, as quoted by Redwood, obtained by distillation at menhaden ml,
among other products, a substance remarkably like petroleum, and a lighting oil
indistinguishable from commercial kerosene.
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HYDROCARBON COMPOUNDS. 371
" 5. Fraas observed exudations of petroleum from a coral reef
on the shores of the Red Sea, where it could be only of animal origin."
In both cases, it wHI be noted, the original source of the material
was organic matter.
llie second theory, which advocates an inorganic origin, is based
largely upon theoretical grounds. It has been shown that hydro-
carbons may be formed under conditions that prevailed deep
in the earth, below any possible deposits of organic matter, and
intimately associated with igneous intrusions. In brief, hydro-
carbons may be formed from the reduction of metallic carbides.
The presence of the material in quanti^ only in unaltered sedi-
mentary rocks remote from all signs of ^eous disturbance must,
however, be regarded as direct evidence in favor of an organic
genesis, whatever may be said with reference to the small quantities
sometimes found in igneous rocks or derived from volcanic sources.'
The relationship which exists between the solid or viscous bitu-
men and the fluidal petroleum has not in all cases been satisfactorily
worked out, though Peckham has shown ^ that in California at least
there are almost infinite gradations from one extreme to the other.
In Ventura County, for instance, the petroleum is held, primarily,
in strata of shale, horn which it issues as petroleum or maltha, accord-
ingly as the shales have been brought into contact ^vith the atmos-
phere, the asphaltum being produced by a still further exposure to the
atmosphere after the bitumen has reached the surface.
The relationship between petroleum and natural gas is scarcely
better defined. That the gas can be derived from petroleum is
undoubted, and indeed the latter apparently never occurs free from
gas. But on the oflier hand, as Professor Orton states, the gas often
originates under many conditions in which petroleum does not
occur, 'ITie formation of marsh gas from decomposing plant
remains on the bottom of stagnant pools, and its presence in coal
mines show with seeming conclusiveness that a part, at least,
' Messrs. Arnold and Anderson have recently shown (Bulleljn No. 31*. U. S.
Geological Survey) that the petroleums of the Santa Maria, Cal., district, are derived
from the Monterey shales, which are made up largely of diatom, fbraminiferal and
ndiolarian remains. ,
■ See report of the Tenth Census, p. 6S.
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372
THE NON-METALUC MmERALS.
of the gas is formed quite independently of petroleum. It would
seem on the whole most probable that no one theory was universaJly
applicable to all cases.
Marsh Gas; Natural Gas. — This is a colorless and cxloriess
gas arising from the decomposition of organic matter protected from
the oxidizing influence of atmospheric air. By itself it burns quietly,
with a. slightly luminous flame, but when mixed with air it fomui a
dangerous explosive. It is this gas which forms the dreaded fire-
damp of the miners. In small quantities this gas may be found and
collected, if desired, from the bottom of shallow pools and stagnant
bodies of water by merely disturbing the decom[>osing plant matter
at the bottom, when the bubbles of the gas will rise to the top. Under
this head may properly be considered the so-called nalural gas, which
has of late years become of so much importance from an economic
standpoint. This gas is, however, by no means a simple compound,
but a variable admixture of several gases, samples from different
wells showing considerable variation in composition, as well as those
from the same well collected at different periods. This last is shown
by the seven analyses following, which may serve well to illustrate
the average composition, though in some instances the percentage
of marsh gas has been found greater.'
I.
11.
III.
IV.
V.
VI.
VII.
it
0.3t>
o-5fi
i
o.is
1.64
9335
0.41
O.J5
0-39
3-41
o.ao
93^5
o.a3
93,67
0.45
o.*s
03s
3-53
0.1 5
1.86
9307
0-49
0-(I
3.M
O.IS
1.42
94.6
0.30
o-SS
o.«)
°X
0.8
93-5»
■ok,
0.55
.00.00
.00.00
100.00
■ocoo
,00.00
.00.00
1, Fostori^ Ohio; II, Hndlay, Ohio; III, St. Marys, Ohio; IV, Muncie, Indiana;
V, Andrison, Indiana; ' VI, Kokomo, Indiana; VII, Marion, Indiana.
Natural gas in quantities to be of economic importance is neces-
sarily limited to rocks of no particular horizon. It is not, however,
' From Orton's Report on Petroleum, Natural Gaa, and Asphalt in Kentucky, pp.
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HYDROCARBON COMPOUNDS.
373
indigenous to the rocks in which it is now found, but occurs in an
overlying more or less porous sand or lime rock into which it has been
forced by hydrostatic pressure. The first necessary condition for
the presence of gas in any locality may indeed be said to depend
upon the existence of such a porous rock as may serve as a reservoir
to hold it, and also thfe presence of an impervious overlying strata to
prevent its escape- In Pennsylvania the reservoir rock is a sand-
stone of Carboniferous or Devonian age; in Ohio and Indiana a
cavernous dolomitic limestone of Silurian (Trenton) age.
Petroleum-— ITiis is a name given to a mixture of complex
hydrocarboii compounds, together with small amounts of their
sulphur nitrogen and oxygen derivatives, which is liquid at ordinary
temperatures, though varying greatly in viscosity, of a black, brown,
greenish, or more rarely red or yellow color, and of extremely dis-
agreeable odor. Its si>ecific gravity varies from 0.6 to 0.9. Tbrou^
becoming more and more viscous, the material passes into the solid
and semisolid forms asphalt and maltha. Chemically it is considered
as a mixture of the various hydrocarbons included in the marsh gas,
ethyline, and paraffin series.
An ultimate analysis of several samples, as given by the reports of
the Tenth Census of the United States (1880), showed the following
percentages of the three essential constituents:
LocHly.
Hydrogo..
Qu-bm.
NitiDSoi.
West Virginia
13-071
u.8,9
86.934
0.54
0.33
I.I09
Petroleum is limited to no particular geological horizon, but is
found in rocks of ail ages, from the lower Silurian to the most recent,
its existence in quantities sufficient for economic purposes being
dependent upon local conditions for its generation and subsequent
preservation. Inasmuch as its accumulation in large quantities
necessitates a rock of porous nature to act as a reservoir, the petro-
leum-bearing rocks are mostly sandstones, though not uniformly so.
Petroleums are found in California and Texas in Tertiary sands; in
Colorado in the Cretaceous; in West Virginia both above and below
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374 THE NON-METALLIC MINERALS.
the Crinoidal (Carboniferous) limestones; in Pennsylvania in the
Mountain sands (Lower Carboniferous) and the Venango sands
(Devonian); in Canada in the Corniferous (Lower Devonian) lime-
stones; in Kentucky in the Hudson River shales (Lower Silurian},
and in Ohio in the Trenton hmestone.
In some instances petroleum oozes naturally from the ground,
forming at times a thin layer on the surface of pools of water, whence
in times past it has been gathered and used for chemical and medic-
inal purposes. The so-called "Seneca oil" thus used some fiity
OT sixty years ago was obtained from a spring in Cuba, Allegany
Counly, in New York. The immense supply now demanded for com-
mercial purposes is, however, obtained altogether from artificial wells
of varying depths, which are in some cases self-flowing, while in
others the oil is raised by means of pumps. Wells of from 500
to 1,500 feet in depth are of common occurrence, while those upwards
of 2,000 feet are not rare. The principal sources of petroleum are
in the United States — New York, Pennsylvania, Ohio, and Oklahoma,
with smaller fields in West Virginia, Kentucky, Tennessee, Illinois,
Indiana, Kansas, Louisiana, Texas, Colorado, and California. The
chief foreign source is the Baku region on the Caspian Sea, and
Galicia, in Austria.
Uses of petroleum. — The early uses of petroleum in America
seem to have been for medicinal purposes only. The oil as pumped
from the wells has but a limited application in its crude condition
excepting as a fuel, and owes its great value to the large and varied
series of derivatives which it yields. A discussion of the methods
employed in obtaining these derivatives belongs properly to the
department of chemical technology, and can not be dwelt upon
here. It must suffice for present purposes to say that the treatment
as ordinarily carried out at present involves a process of destructive
dbtillation whereby the crude material, heated under pressure, is
resolved into a variety of products of different densities, and varying
from gaseous through liquid to solid forms. Prominent among these
derivative may be mentioned, aside from the gaseous compounds,
rhigolene, gasoline, naphtha, benzine, kerosene, various lubricating
oils, paraffin, and the soild residues (coke, etc.). Various phar-
maceutical compounds are prepared from petroleum products, many
0 Got>^lc
HYDROCARBON COMPOUNDS. 375
of which axe well known to the publk, as vaseline, cosmoline, etc.
It is also used ss a basis for ointments and in soaps.
For full and detailed information relative to the petroleum
industry and general distribution of allied bituminous compounds
throughout the world, the reader is referred to the works mentioned
in the bibliography, that of Boverton Redwood being the most sys-
tematic and complete,
Aaphaltom; Mineral Pitch.— These are names given to what
are rather indefinite admixtures of various hydrocarbons, in part
oxygenated and which, for the most part solid or at least highly
viscous at ordinary temperatures, pass by insensible gradations into
pittasphalt or mineral tar, and these in turn into the petroleums.
They are characterized by c black or brownish-black color, pitchy
luster, and bituminous odor. The solid forms melt ordinarily at a
temperature of from 90° to 100* F., and bum readily with a bright
flame, giving off dense fumes of a tany odor. The fluidal varieties
become solid on exposure to the atmosphere, owing to evaporation
of the more volatile portions.
The nature of the material, its mode of occurrence, and indeed
the uses to which it can be put, vary to such an extent with each indi-
vidual occurrence that a few only of what are the most noted or best
known can here be mentioned.
Island oj Trinidad.— The occurrence on this island of an immense
body of asphaltic material has been known for upwards of a hundred
years, and numerous, often widely differing, accounts of it are to
be found in literature. The latest and perhaps most satisfactory,
when everything is taken into consideration, is that of S. F. Peckham.*
The deposit, which covers an area of nearly 100 acres, is situated at
an elevation of 138 feet above the level of the sea (see map, Fig. 53),
and on superficial examination has an appearance such as has
caused it to be known by the not wholly inappropriate name of the
Pitch Lake of Trinidad. The depth of the deposit, in various
parts, has been estimated at from 18 to 78 feet. According to
Richardson the maximum depth is 35 feet. Early accounts de-
' Amerioin Journal of Science, L, 1S95, pp. 33--51.
ovGoo'^lc
jvGooi^lc
HYDROCARBON COMPOUNDS. 377
scribed the pitch at the margin of the lake as cold and hard, becom-
ing gradually warmer and more viscous toward the craiter, until a
point is reached where it is too soft to support the weight of a man
and actually " bofling." However, this may have been years ago;
the material b now sufficiently firm over the entire surface to sup-
port men and teams. The deposit is commonly regarded as a
mud volcano, the bitumen being still brought up intermixed with
water and mud, die numerous small islands which occupy the .sur-
face of the lake being but masses of earthy matter buoyed up by
the pitch. Though the deposit has been worked for many years
find thousands of tons of asphalt removed, no appreciable impres-
sion has as yet been produced upon the amount of material available.
The crude material has the following composition and physical
characteristics: '
Specific gravity, 1.28; hardness at 70'^ F., 3.5 to 3 of Dana's scale;
color, chocolate-brown; composition:
Bitumen 39-83
Earthy matter 33-99
Vegetable matter 9.31
Water 16.87
Total 100.00
Cuba- — Asphalt in some of its varieties occurs in nearly every one
of the Cuban provinces and in several instances in sufficient abun-
dance to be of economic importance. In all instances thus far de-
scribed,' the material occurs in veins or pockets, or exudes in
the form of springs, usually in serpentinous rocks or limestones.
As long ago as 1837 R. C. Taylor described ' a deposit of asphalt
— at that time r^arded as bituminous coal — occurring some 10
miles east of Havana as occupying an irregularly branching fis-
sure from I to 9 feet in width in a soft clay rock, which is
now known to be a decomposed eruptive. The appearance of the
' F. V. Greene. Asphalt and Its Uses. Transactions of the American Institute
of Mining Engineers., 17. 1888-89, P- 3SS-
■ See Report on Ge<dogical ReconnoUsanc« of Cuba, 1901.
' London and Edinburgh Philosophical Magazine and Journal of Science, X, 1837,
J, Google
378
THE NON-METALUC MINERALS
vein, in vertical section, is shown in Fig. 54, the bottom ol the cut
representing a distance from the surface of 30 feet. The asphalt
itself was described as of a jet-black color, resplendent luster,
conchoidal fracture, and with a specific gravity varying from
1.42 to 1.97. An analysis by
T. G. Clemson showed 63 per
cent volatile matter, 34.97 per
cent carbon, and 2.03 per cent
ash.
Several interesting submarine
deposits exist in Cardinos Bay,
which may be mentioned on ac-
count of the unique methods of
mining. These have been de-
scribed by J. L. Hance. The *
country rock is a limestone and
the asphalt of a brilliant black
color and about as friable as
cannel coal. In mining a lighter
is anchored directly over the
body of asphalt and a long,
pointed iron bar raised by a
winch, on board, dropped upon
it, the weight of the bar being sufficient to break away pieces of
the asphalt, which are then collected by divers and sent to the sur-
face in nets. The material has been utilized in making varnish,
and formerly brought a high price.
A large deposit of an inferior grade, and used mainly for roofing
is situated near Diana Key, 15 miles from the city of Cardenas, and
a massive bed, some 12 feet in thickness, near Villa Clara. Material
from this last source has, during years past, been used for making
the illuminating gas used in the city.
Sandstones and limestones are sometimes so impregnated with
bituminous matter that they may be used as sources of the material
by refining processes or for the direct manufacture of pavements by
simply crushing. Such are the so-called bituminous or asphaltic
ESnl rocks and lim;;stones of Kentucky, Texas, Oklahoma,
Fk). S4-— Aiphalt vdn, Cuba,
[After R. C. Taylor.J
:b,Got>^lc
HYDROCARBON COMPOUNDS. 379
Utah, Colorado, Calilomia, Wyoming, and other States, and of
Canada' and Spain.
According to G. H. Stone,' the asphaltic saodrock of western
Colorado and eastern Utah consists of grains of sand which are in
contact with one another, the spaces between the grains being filled
with asphalt, the proportioned amount of which varies up to 15 per
cent by weight, or 27 per cent by volume. One stratum of fully
charged rock in the region described was nearly 40 feet in thickness,
though usually the strata of high-grade material are not more than
4 to 10 feet thick and alternate with others which are quite poor
or barren, so that the amount of " pay rock " is often grossly
exaggerated.
Asphaltic sands and sandrocks are of common occurrence in the
inunediate vicinity of the Coast Range in California from l^oint
Arena, north of San Fruicisco, to the southernmost part of the
State.^ 'l^e deposits occur almost invariably as sands and shales,
belonging to the Neocene formations, impregnated with varying
amounts of bitumen, though rarely exceeding 15 to 20 per cent by
we^t. The material is mined from open cuts, rarely from shafts,
and is utilized in large part for street-paving purposes.
In the region south of the Canadian River, in Oklahoma, asphalt
and asphaltic lime and sandstones occur over extensive areas, the
more important bemg in what are known as the Buckhom and
Brunswick districts. The rocks of the regions are wholly sedimen-
tary, and the bituminous members belong mainly to tiie Lowo:
Silurian (Ordovician), Coal Measure, and Cretaceous formations.
In the eastern part of the territory, the Ten Mile district, is found
a very pure, brittle material somewhat resembling albertite (p. 383),
and for which the name impsonite has been suggested,^ It contauis
some 86 per cent of carbon and 8 per cent of hydrogen. The material
is found in a vein in greenish gray shales, having a trend of 1 5" N.
to 20" E., and pitching 45° to 65° to the eastward.
' American Jouro&l of Science, XLII, 1891, p. 148.
'See Thirteenth Anniul Report State Mineralogist of Califomia, 1896, &I90
Twenty-second Annual Report, U. S. G. S., 1900-1901, Pt. I, pp. 109-464.
* After the Impaon Valley, where it occurs. See Eldridge's paper, Twenty-second
Annual Report, U. S. G. S. Ridiaidson regards this material u giahamite.
J, Google
380 THE NON'METALUC MINERALS.
At the Rabton quarry in the Buckhom district the rock ' is a
massive Ordovician sandstone some 15 feet in thickness "overlaid
by some 75 to 100 feet of conglomerate. The bitumen contents
amounts to between 10 and 12 per coit. At the quarry of the
Gilsonite Paving and Roofing Company in this same district, the
bitumoi is in strata referred to the Lower Coal Measures. (See
section, Fig. 55.) The bitumen-bearing member here (No. 9 in
section) is a hard massive limestone, the upper portbn of w^hich
[U. S. Geological Survey.]
I and 3, conglomerate; 3, shales; 4, conglomerate; 5, quartzitc, 6, UmestonC; bi-
tuminous; 7, limestone, somewhat bituminous; 8, calcareous with nood fiber and
coal; 9, limestone averaging 14 per cent bitumen; 10, shale; It, conglomerate;
la, bituminous shale.
is highly fossiliferous, and the lower sometimes conglomeratic. It
yields on an average some 14 per cent of bitumen.
Uses. — The uses of the conunon type of material such as is known
simply as asphalt are quite varied. The wells of Babylon are stated
to have been cemented with it, and doubtless it was so used in other
ancient cities. It was also, as at present, used for making vesseb
water-tight. At the present day the refined asphalts are used as a
varnish or paint, as an insulating material, for waterproofing, as a
cement in ordinary construction, arid as a cement m roofing and
paving compounds. For these purposes it is first tempered with
some form of oil, the kind and amount used depending on the pur-
poses to which it Is to be applied. A mixture of asphalt and sand
forms the ordinary concrete for sidewalks and basement floors.
The most extensive use of asphaltic compounds is at present for
street pavements, the material for this purpose being mixed with
0 Got>^lc
HYDROCARBON COMPOUNDS. 381
fine sand and sometimes powdered limestone.' The asphaltic sands,
sandstones, and limestones are sometimes so evenly impregnated
with bituminous matter that they may be crushed and applied
directly to the roadbed. The uses to which are put the higher
grades of asphaltic compounds, such as are designated by special
names, are given further on.
Hanjak. — ^The local name of tnanjak b applied to a variety
of bitumen somewhat resembling uintaite, occurring on the island
of Barbados, in the West Indies. The material is a ver^^ pure hydro-
carbon of a black color, but yielding a brown powder, high luster, and
with a bright conchoidal fracture. Il is brittle, and so friable that it
can be ground to powder between the thumb and fingers. It occurs
in seams or veins, varying from one-fourth of an inch to 30 feet in
thickness, cutting the coimtiy rock, which is an argillite or shale,
at all angles with the horizon and with a general NNE. strike. In
places the bituminous matter has saturated the entire rock in the
neighborhood of the veins, producing a shale from which as much
as 37 gallons a ton of petroleum have been obtained by destructive
distillation. Thus far the greatest development is along a vein
200 feet in length, 100 feet in -depth, and from 8 to 9 feet in width.
One vein, which has been explored to a depth of 200 feet, is stated
to have dwindled down to a width of 6 feet, though 30 feet wide
at the surface.^
Manjak is stated ^ also to occur on the island of Trinidad some
12 miles from Pitch Lake, with which, however, it apparently has
no connection. The material occurs in form of a steeply pitching
seam which as perforated by shafts shows a width of 10 feet at a
depth of 55 feet below the surface and of 33 feet at a depth of 200
feet. The material yielded on analysis as below: *
' Asphalt and its Uses, TmnsactioDS of the American Institute o( Mining Engineers,
XVII, 1889, p. 335. See also The Modem Asplult Pavement, by Clifford Ridiaid-
son, Wiley & Sons; New York, 1905.
' VV. Merivale, Engineering and Mining Journal, LXVI, 1S98, p. 790; alao tho
Mineral Industry, \1, 1897, p. 54,
' Engineering and Mining Journal, April 14, 1906, p. 710.
'Analyses I and II by B. Redwood, III by P. Camody.
ov Google
THE NON-METALUC MINERALS.
I.
11-
III.
Water
4-1
>7-S
71.1
4.4
Si
4.00
3.97
1.14
360" F.
«7.>
3.06
0.4
4.»
^Vl
M^lS^nt'! :.".;:;:::;;:::::;::::;::
Uses, — Like gUsonite, the material is used for making varnishes,
insulating electric wires, etc., bringing the price of this mineral,
from $5 to $10 a ton, according to quality and freedom from impur-
ities.
Elaterite; Mineral Caoutchouc. — This is the name given to
a soft and elastic variety of bitumen much resembling pure india-
rubber. It is easily compressible in the fingers, to which it adheres
slightly, of a brownish color, and of a specific gravity varying from
0.905 to 1.00. It has been described from mines in Derbyshire and
ebewhere in England, but so far as the writer is aware is of no com-
mercial value. Its composition, so far as determined, is carbon,
85.47 pc"" "ntl hydrogen, 13.28 per cent.
WtUtziUlte. — The name wurtzillite has been given by Prof. W.
P. Blake to a hydrocarbon very similar in appearance to the uintaite
(described on page 386), but differing in physical and chemical prop-
erties. It is a fine black solid, amorphous in structure, brittle when
cold, breakir^ with a conchoidal fracture, but when warm tough and
elastic, its elasticity being best compared with that of mica. If bent
too quickly it snaps like glass. It cuts like horn, has a hardness
between 2 and 3, a specific gravity of 1.03, gives a brown streak,
and in very thin ilakes, shows a garnet-red color. It does not fuse
or melt in boiling water, but becomes softer and more elastic; in
the flame of a candle it melts and takes fire, burning with a bright
luminous fiame, giving off gas and a strong bituminous odor. It is
not soluble in alcohol, and but sparingly so in ether, in both of which
respects it differs from elaterite. In the United States it occurs near
ov Google
HYDROCARBON COMPOUNDS.
l&Z
Scofield, Carbon County, and in the Uinta Mountains of Wasatch
County, Utah.
Albertite. — This is a brilliant jet-black bitumen compound
breaking with a lustrous, conchoidal fracture, having a hardness of
between i and 2 of Dana's scale, a specific gravity of 1.097, black
streak, and showing a brown color or very thin edge. In the flame
of a lamp it shows signs of incipient fusion, intumesces somewhat,
and emits jets of gas, giving off a bituminous odor; when rubbed it
becomes electric. According to Dana it softens slightly in boiling
water, is very slighdy soluble in alcohol, 4 per cent in ether, and some
3 per cent soluble in turpentine. The following is the composition
as given by Wetherill: Carbon, 86.04 pc cent; hydrogen, 8,96 per
cent; oxygen, 1.977 P^i" cent; nitrogen, 2.93 per cent; ash, 0.10
per cent.
Dr. Antisell made the following comparative tests to show the
relative richness of the matena) in volatile matter:
Co^
A^iar
A.^.
AJbenit*.
Volatile malter
"■79
70-is
19.85
7.-67
18.04
o.»9
59-88
39-S9
0-S3
100.00
100.00
100.00
100.00
The mineral is described ' as occurring in "true cutting veins" in
shale of Lower Carboniferous Age in Hillsborough County, New
Brunswick. The shales themselves contain a lai^e amount of car-
bonaceous matter and by distillation have been made to yield 30
gallons to the ton of refined illuminating oil. They contain immense
numbers of fossil fish and are mostly inflammable. The veins vary
from a fraction of an inch to 12 feet in width with a general N, 65°
east course, sometimes vertical and sometimes inclined northwest-
ward from 75° to 80°. They enlai^ and contract very irregularly,
but in general increase in thickness as followed downward. Hitch-
' American Journal of Science, X3CXIX, 1865, p. 967; see fttso Dawson's Acadian
Geology. 3d ed., pp. 331-141.
ov Google
384 THE NON-METALUC MINERALS.
cock regarded the veins as having beai filled by the injection of the
material in a liquid state and being subsequently indurated.
Uses. — ^This vein seems to have been discovered about 1840 by
Dr. Abraham Gesner, who, in 1850, took out a patent in the United
States for the manufacture of illuminating gas from this and otho
asphalts.' A company was organized and for some years active
mining operations were carried on, but which have been discontinued
since the discovery of petroleum.
Grahamite. — Grahamite has a less brilliant luster and more
coke-like aspect than albertite. It has been described by Dr. Henry
Wurtz as occurring in shrinkage fissures running N. 76° to 80° E.
in Carboniferous shales and sandstones, on a branch of Hughes
River, Ritchie County, West Virginia. It is completely soluble in
chloroform and carbon disulphide, nearly so in turpentine, and par-
tially so in naphtha and benzine, but not at all in alcohol. Melts
somewhat imperfectly, beginning to smoke and softoi like coking
coal at a temperature of about 400° F. Specific gravity, 1. 145.
As occurring in the vein the materiaj shows four distinct, though
somewhat irregular, divisional planes, having a general parallelism
with the walls. Next to the walls the structure of the mineral is
'coarsely granular, with an irregularly cuboidal jointed cleavage, very
lustrous on the cleavage surfaces. The material in immediate con-
tact with the walls usually adheres thereto very tenaciously, as if
fused fast to the granular sandstone.
The general aspect of the mass has led to the conclusion that
file vein is a fissure which has been filled by exudatbn, in a pasty
condition, of a resinoid substance derived from or formed by some
organic matter contained in deep-seated strata intersected by the
fissure or dike.
J. P. Kimball has described ^ a deposit of similar material on the
west bank of the Capadero River in the Huasteca, Vera Cruz,
Mexico. The country rock is a fossiliferous Tertiary shale overlwd
' ReTien of reports on the Geological Relations, etc., of the cml of the Albeit
Coal Mining Company, situated in Hillsborough, Albert County, New Brunswick,
as written and compiled by Charles T. Jackson, M.D., a Fellow of the Geok^ical
Society of London, etc., New York, 1853.
' American Journal of Science, XII, 1876, p. 177.
1 Got>^lc
HYDROCARBON COMPOUNDS. 385
by conglomerate. The grahamite occurs in a fissure some 34 inches
in thickness terminating in an " overflow " some 6^ feet in maximum
thickness, thinning away at the edges, but the full extent of which
was not determined. The evidence showed that the fissure had been
filled by material oozing up from below and spreading out upon the
surface prior to the deposition of the overlying gravel. The strike
of the fissure was nearly north and south. The material b more
uniformly lustrous than that from Ritchie County, and of a greater
coherence, though none the less distinctly cleaved and jointed. An
analysis of a sample from the Cristo mine, as given, yielded results
as follows:
CODltitUOltS.
Per Cent.
6.-33
0.46
0.36
3' -63
-^—37-86
1.156
aZ "::.v.v.::;:;::;::;:;;:::
Carbonite or ITatural Coke is the name given to a peculiar
hydrocarbon compound occurring in the form of beds like bitumin-
ous coal, in Chesterfield County, Virginia, and having a dull black
and, for the most part, lusterless aspiect, somewhat resembling coke.
An analysis by Wurtz ' yielded the following:
Coke.
4-57
Volatile combustible matter 15-43
Other analyses by Dr. T. M. Drown * on two portions, the one
dull and lusterless and the other lustrous, yielded:
' Tranaaclknu of tbe American Institute of Mining Engineers, III, 1875, p. 456.
■ Idem, XI, T8S3, p. 448.
ovGoo'^lc
THE NON-METALUC MINERALS.
pDull^^
■jssr
"■37S
I -35°
15-47
3.ao
79 33
0.69
8..S3
100.00
4.08
100,00
1.60
TKe material occurs interbedded with shales much like ordinal^
bituminous coal, there being, according to Raymond, three distiact
beds vatying from i foot 9 inches to g feet in thickness, interstratified
with the shales, the lowermost bed of 9 feet thickness being under-
laid by fire clay. The origin of the material is in doubt, the eaHier
writers regarding it as a bituminous coal coked by the heat of intru-
sive rocks. Later writers throw doubt upon this by stating that
there are in the vicinity no intrusives of^such size as to warrant any
such assumption.
Uses. — ^The material is said to bum without smoke or soot, like
anthracite, and to have been used for domestic purposes.
Uintaite; Gilsonlte.— This is a bUck, brilliant, and lustrous
variety of bitumen, giving a dark-brown streak, breaking with a beau-
tiful conchoidal fracture, and having a hardness of 2 to 2.5 and a
specific gravity of 1.065 to 1.07. If fuses readily in the flame of
a candle, is plastic but not sticky while warm, and unless highly
heated will not adhere to cold paper. Its deportment fa stated to be
much like that of sealing wax or shellac. Like albertite and gra-
hamite it dissolves in turpentine and is not soluble in alcohol. It
is a nonconductor of electricity, but like albertite becomes electric
by friction. Its composition as given is: Carbon, 80.88 per cent;
hydrogen, 9.76 per cent; nitrogen, 3.30 per cent; oxygen, 6.05 per
cent, and has, 0.01 per cent. The name uintaite was given this
substance by W. P. Blake in 1885, after the Uinta Mountains, where
it was first found. It is also known under the trade name of
gilsonlte, after S. H. Gilson.
ovGoO'^lc
HYDROCARBON COMPOUNDS. 387
Occurrence. — According to George H. Eldridge* the gilsonite
deposits of Utah occur filling a series of essentially vertical fissures
in Tertiary sandstones lying within the Uncompahgre Indian Reser-
vation, or in its immediate vicinity. The fissures have smooth,
regular walls, and vaiy in width from the sixteenth of an inch to
18 feet, and in length from a few hundreds yards to 8 or 10 miles.
The laiger veins are somewhat scattered, one lying about 3}
miles east of Fort Duchesne, a second in the region of the Upper
Evacuation Creek, and the three others of most importance in the
vicinity of the White River and the Colorado-Utah line. Besides
these there b a 14-inch vein crossing the western boundary of the
reservation near the fortieth parallel; another about equal size about
6 miles southeast of the junction of the Green and White rivers;
a third in the gulch 4 or 5 miles north of Ouray Agency, west of the
Duchesne River, and a number from one-sixteenth of an inch to a
foot in thickness in an area about 10 miles wide, extending from
Willow Creek eastward for 25 miles along both sides of the Green
and White rivers. The veins are sometimes slightly faulted, and
often pinch out to mere feather edges. The filling material is quite
structureless excepting where, as near the surface, it has been ex-
posed to the atmospheric influences, where it shows a fine pencillate
or columnar structure at right angles to the walls. The walls of the
veins are impregnated with the gilsonite for a distance of several
inches, but all indications point to the veins themselves having been
filled, not by lateral impregnation, but by injection from below.
The mining of uintaite is conducted in the ordinary manner by
means of shafts and tunnels. The work is, however, attended with
considerable difficulty and some danger, owing to the fine dust
arising from it. This penetrates the skin and lungs, and is a source
of great annoyance, and moreover becomes highly explosive when
mixed with atmospheric air.
Uses. — The principal use of uintaite thus far has been in the
manufacture of varnishes for ironwork and baking japans. It is
not well adapted for coach varnishes. It has been also used for
mixing with asphaltic limestone for paving material. Other pos-
' Seventeenth Annual Report U. S. Geological Survey, 1895-96, Pi. I, p. 915. -
ovGoo'^lc
388 THE NON-METALUC MINERALS.
sible uses suggested are as below: For preventing electrolytic action
on iron plates of ship bottoms; for coating barbed- wire fencing, etc.;
for coating sea walls of brick or masoniy ; for covering paving brick;
for acid proof lining for chemical tanks; for roofing pitch; for insu-
lating electric wires; for smokestack paint ; for lubricants for hea\'y
machinery; for preserving iron pipes from corrosion and acids; for
coating poles, posts, and ties; for torredo-proof pile coating; for
covering wood-block paving; as a substitute for rubber in the manu-
facture of cotton garden hose; as a binder pitch for culm in m^'\c\xt^
brickette and eggette coal.
3. ozokemte; MmzRAL wax; native paraffin.
This is a wax-like hydrocarbon, usually with a foliated structure,
soft and easily indented with the thumb nail ; of a yellow-brown or
sometimes greenish color, translucent when pure, with a greasy feel-
ing, and fusing at 56* to 63* F.; specific gravity, 0.955. ^^ ^ essen-
tially a natural paraffin. The name is derived from two Greek
words, signifying to smell, and wax. Below is given the composition
of Q) samples from Utah, and (11) from Boryslaw, in Galicia.
Coialiluente. 1.
IL
Carbon 85^7
85.78
14.19
Total 100.04
100.07
The substance is completely soluble in boiling ^er, carbon
disulphides, or benzine, and partially so in alcohoL
Ths following, from a paper by Boverton Redwood,' will serve to
show the character of the material from the various reported sources:
Baku. — Specific gravity, 0.903; melting point, 76° C:
Coi»tituenti.
Per Cent.
81.80
13.80
4.40
100.00
' Joumal of the Society of Chemical Induitiy, XI, 1891, p. 114.
Coo'^lc
HYDROCARBON COMPOUNDS.
Persia. — Dark green, rather hard; specific gravity, 0.925:
CoMtttuenU.
Pa- Cent.
'-35
16-73
7-34
100.00
Boryslaw. — Specific gravity, 0^30. I, dark yellow; 11, dark
brownish black:
CoMtitqanto.
L
II.
Benzine, 0.710 to 0.750.......
Kerosene, 0.780 to oijo
Lubricating oil, 0.895
"1
3-00
6-9S
Si.»7
4-63
4-S3
.00.00
■00.00
Occurrences. — Ozokerite occurs in the United States in Emery
and Uinta counties, Utah, where, in the form of small veins in
Tertiary rocks, it extends over a wide area. It is also found in.
Gahcia, Austria, in Miocene deposits; in Roumania, Hut^ary, Russia,
and other Asiatic and European localities. As a rule, the deposits
are in beds of Tertiary or Cretaceous age, the Boryslaw, Dwiniacz,
and Starunia (Galicia) deposits being in Miocene while the Kouban
deposits are on the borders of the Lower Tertiary and Upper
Cretaceous. In Teheleken ozokerite is found accompanying petro-
leum in pockets in beds of sand above the clay shales and Muschel-
kalk of the Aralo-Carpathian formation. In southern Utah and
Arizona it occurs in Tertiary rock, probably Miocenci
ov Google
390 THE NON-MET^LUC MINERALS.
The Gatician deposits are by far the most important of those
above mentioned, Boryslaw, a town of some 14,500 inhabitants,
fonning the principal seat of the mining and manufacturing indus-
try.
The soil of the valley in which Boryslaw lies is a bed of diluvial
deposit some meters in thickness. In sinking a shaft, first yellow
clay, then rounded flints and gravel, and then plastic clay are met
with. Below this sandstone and blue shale, much disturbed, alter-
nate, and it is in these beds, which have a thickness of some 200
meters, that the ozokerite is found. The ozokerite-bearing forma-
tion lies on a basis of petroliferous menilite shale, the strata of which,
as they approach the surface, are disposed almost vertically, but
incline toward the south. The strata are composed of layers of
coarse-grained sandstone, green marl, fine-grained sandstone with
veins of calcite, dark shale alternating with gray sandy shale, imper-
ceptibly merging into the main beds of the non-petroliferous sandstone
and shale. Below these are Carpathian sandstones of the Lower
Eocene (Nummulitic sandstone) and Upper Cretaceous forma-
tbns.
The geological conditions prevailing at Dwiniacz and Starunia are
similar to those at Boryslaw, but the ozokerite is more largely mixed
with petroleum- The soil is gray and red diluvial clay, below which
is a bed of gravel, lying on the Miocene formation, in which the
ozokerite and petroleum occur in association with native sulphur,
iron pyrites, and zinc blende. Still lower a highly porous calcareous
rock is met with, containing cavities filled with petroleum and
sulphureted water, and below this again is marl with gypsum and
the salt-clay formation destitute of petroleum. The ozokerite occurs
in the form of veins of a thickness ranging from a few millimeters to
some feet, and is accompanied with more or less petroleum and
gaseous hydrocarbons. It fills the many fissures with which the
disturbed shales and Miocene sandstone abound, and frequently
forms thus a kind of network.
The Boryslaw deposit extends over a pear-shaped area, the ajds
of which lies E. 30° S. The upper layers of the richest portion of
the deposit occupy an area of about 21 hectares, with a length of
ovGoO'^lc
HYDROCARBON COMPOUNDS. 391
1,000 meters and a maximum breadth of 350 meters, but outside this
there is an outer zone of less productive territory whicb increases the
total superficies to about 60 hectares, with dimensions of 1,500 metere
by 560 meters. The deposit narrows considerably as the depth
increases, and at a distance of 100 meters from the surface of the
ground has a breadth of only 300 meters.
Uses. — The crude ozokerite, after being freed so far as possible
from impurities, b melted and cast into loaves or blocks of the form
of a. truncated cone, and weighing about 50 to 60 kilos. There are
two or three recognized commercial qualities of the melted and
cast ozokerite. The first quality is transparent in thin sheets, and
it color ranges from yellow to greenish brown. Adulteration by means
of crude petroleum, heavy oils, the residues from refineries, asphal-
tum, and even earthy matter, are not unknown, and occasionally
by a process of double casting the exterior of the block is made to differ
in quality from the interior. ^
The refined material is known as ceresin. It is used for candles,
as an adi;lterant or a complete substitute for beeswax, and in the
manufacture of ointments and pomades. A residual product from
the purifying process, of a hard, waxy nature, is combined with india-
rubber and used as an insulating material for electrical cables.
In this form it is known as okanUe. A ball blacking, used on the
heels of shoes, b also manufactured from it.
The names Scheererite, Hatchettite, Fichtelite, and Konlite are
^plied to simple hydrocarbons allied to ozokerite found in beds
of peat and coal, but, so far as the writer is aware, never in such
abundance as to be of commercial value.
4. KEsms.
Sncdnite; Amber. — The mineral commonly known as amber
is a fossil resin consisting of some 78.94 parts of carbon, 10.53 parts
of oxygen, and 10.53 parts of hydrogen, together with usually from
two to four-tenths of a per cent of sulphur. It is not a simple resin,
but a compound of four or more hydrocarbons. According to
ov Google
39* THE NON-METALLIC MINERALS.
Berzelius, as quoted by Dana, it consists mainly (85 to 9c per
cent) of a resin which resists all solvents, along with two other resins
soluble in alcohol and ether, an oil, and zj to 6 per cent of succinic
acid.
The mineral as found is of a yellow, brownish, or reddish color,
frequently clouded, translucent or even transparent, tasteless, becomes
negatively electrified by friction, has a hardness of 2 to 2.5, a specific
gravity when free from inclosures of 1.096, a conchoidal fracture,
and melts at 250" to 500* F. without previous swelling but boils
quietly, giving ofiE dense white fumes with an aromatic odor and
very irritating effect on the respiratory organs.
As above noted, amber is a fossil resin or pitch, an exudation
product principally of the Pinus succintfer, a now extinct variety
of pine of the Tertiary period.
Occurrence. — Amber or closely related oimpounds has been
found in varying amounts at numerous widely separated localities,
but always under conditions closely resembling one another. The
better-known locahties are the Prussian coast of the Baltic; on the
coast of Norfolk, Essex, and Suffolk, England; the coasts of Sweden,
Denmark, and the Russian Baltic provinces; in Galicia, Westphalia,
Poland, Moravia, Norway, Switzerland, France, Upper Burmah,
Sicily, Mexico, the United States at Martha's Vineyard, and near
Trenton and Camden, New Jersey.
The substance occurs in irregular masses, usually of small size.
One of the lai^est masses on record weighed 18 pounds. This is
now in the Berlin Museum. A mass found in the marl pits near
Harrisonburg, New Jersey, weighed 64 ounces. This last is pre-
sumably not true amber, since it contained no succinic acid, which
is now regarded as the essential constituent.
The amber of commerce comes now, as for the past two thousand
years, mainly from the Baltic, where it occurs in a strata of lignite-
bearing sands of Lower Oligocene age. According to Berendt,'
there are two amber -bearing strata, the one carrying the amber in
nests and both underlaid and overlaid by clayey seams, and the
■Schriften der FbjNkalbcb-dkonomischen Gesetlschaf t, Vn, 1866.
ov Google
HYDROCARBON COMPOUNDS. 393
second and lower a glaucomtic sand commonly known as the blue
earth. The material is mined by open cuts where the strata come
to the surface, by means of shafts and tunneb, as in coal mining,
and by dredging or diving, in the latter case the material having
been derived originally from the amber-bearing strata and redeposited
on the present sea-bottom.'
The pieces obtained vary from the size of a pea to that of the hand.
The annual product at present amounts to some 300,000 pounds,
valued at about $1,000,000. The price of the material varies greatly
with the size and purity of the pieces. Pieces of one-fourth pound
weight bring about $15 a pound, while the small granules will not
bring one-twentieth that amount. The value of the material is
often lessened by the presence of flaws and impurities or inclosures,
such as insects and twigs of plants.
Uses. — Amber is used mainly in jewelry, in small ornamentations,
and smokers' goods, the smaller pieces being used in making varnish.
The clear pieces and chippings have of late been compressed by a
newly discovered process into tablets some 6 by 3 by i inches in
size, which can be utilized in the manufacture of articles for smokers'
use.
Retinite. — The name retinite is used by Dana to include a con-
siderable series of fossil resins allied to amber, differing mainly in
containing no succinic acid. They occur in beds of brown coal of
Tertiary and Cretaceous Age, much as does the amber proper. The
principal varieties that have thus far proven of any economic impor-
tance are noted below:
Cbemawinite.^ — This is the name given by Professor Harring-
ton,* to an amber-like resin foutid associated with woody d^ris
on the southeast shore of Cedar Lake in Canada. The material
occurs in granular form and in smalt sizes only, such as are quite
unsuited for manufacturing purposes. The true gum-bearing
stratum, if such exists, has not yet been discovered, the material
thus far found being washed up by waves on t le beac'i. Accord-
' According to the Engineering and Mining Journal of May 10, 1893, the dred^
Ing process on the Bahk coast has been discontinued as no longer profitable.
'American Journal of Science, XLII, 1S91, p. 331.
ovGoo'^lc
394 THE NON-METALLIC MINERALS.
ing to O. J. Klotz,' the beach matter resembles the refuse of a
sawmill, no stones and very little sand being associated with the
dtfbris, which is everywhere underlaid by clay. The principal
beach was estimated to contain some 700 tons of granular material.
A somewhat similar resin is found in the lignite and soft greenish
sandstone near Kuji, Japan.' It is reported as being of inferior
quality, opaque, cloudy, and much fissured. It is, however, mined
and shipped to Tokio, where it is presumably worked up into small
ornaments.
The so-called Burmese amber, or Burmite from the Hukong
Valley, is reported as occurring in a soft blue clay, probably of Lower
Miocene Age, and in lumps not exceeding the size of a man's
hand.
Gum copal. — The name copal or gum copal i~> mad: to cov:r,
commercially, a somewhat variable series of resins found for the most
.part buried in the sands in tropical and subtropical regions. They
are in general amber-like or resin-like in appearance, of a hardness
inferior to that of true.amber, of a light yellow to brown color, brill-
iant glass-like luster, transparent to translucent, and have a con-
choidal fracture. When cold they are brittle and can be readily
crushed to powder, but possess a slight amount of elasticity. When
rubbed on cloth they become electric and emit a peculiar resinous
odor. The specific gravity varies from i to i.io. When heated
the material softens, swells up, and bubbles, finally melting, remain-
ing liquid until carbonized. It bums with a yellow smoky flame;
is partially soluble in alcohol, wholly so in ether, and also in turpen-
tine on prolonged digestion. The so-called Kauri gum is a light
amber-colored variety from the Dammara Australis, a living conifer-
ous tree of New Zealand. The principal source is the northern
portion of the Auckland provincial district which has exported since
1863 (and up to 1897) some 134,630 tons of gum valued at
jf5,394,687, the product for 1890 being 7,438 tons valued at
^^378.563-
The gum-digging industry is one that gives employment to both
' American Jeweler, Ho, i, XII, iSga.
* Tranaaclions o( ihe American Insiiluie of Mining Engineers, V, 1876. p. 165.
J, Google
HYDROCARBON COMPOUNDS. 395
Euro[)ean5 and natives.* The gum is found but a short distance
bebw the surface, and is dug with the aid of a few implements, the
entire outfit often consisting of a steel prod, a spade, and knife and
haveisack. With the copal is often found the more amber-like resin
ambrite, which has a slightly greater hardness, a specific gravity
of 1.034, a yellowish gray to reddish color and which yields on an-
alysis carbon, 76.88; hydrogen, 10.54 per cent, and oxygen, 12,77
per cent. It becomes strongly electric by friction and is insoluble in
alcohol, ether, chloroform, benzine, or turpentine, and bums with
yellow, smoking fiame. Quite similar to the kauri gum is the copal
of the African coasts. According to Dr. F. Welwitsch' gum of the
west coast and probably all the gum resin exported under this name
from tropical Africa is to be regarded as a fossil resin produced by
trees which, in periods long since past, adorned the forests of that
continent, but which are at present either totally extinct or exbt
only in a dwarfed posterity. The gum, which is called by the Bunda
negroes Ocate Cocolo, or Mucocoto, is found in the hilly or mountain-
ous districts all along the coast of Angola, including the districts of
Coi^o and Benguella, and is brought by the natives to the different
market places on the coast of Angola, including the districts of Congo
and Benguella. The larger quantities of the resin are mostly found
in the sandy soil, and it is apparently limited in its geographical dis-
tribution with that of the tree Adansonia digitata, the lands in the
Government of Benguella extending along the mountain terrace of
Amboin, Selles, and Mucobale, south of the Cuanza River being
most productive, having yielded between 1850 and i860 some
1,600,000 pounds of gum a year.
"It is a general and widely spread opinion," writes Welwitsch,
" that the gum copal in Angola is gathered from trees; but this, accord-
ing to my own observation, is obviously erroneous, for the gum
copal is either dug out of the loose strata of sand, marl, or clay, or
else it b found in isolated pieces washed out and brought to the
surface of the soil by heavy rainfalls, earthfalls, or gales; and such
' Report of ihe Mining Industry of New Zealand for )S88. In the report for 1SS7
il is stated that "according to the last census" the number of persons employed in
the occupation of gum digging was 1.3B3.
'Journal of the IJnnaean Society of London, Botany, IX, 1866, p. 187.
ovGoo'^lc
30 THE NON-METALUC MINERALS.
pieces, where found, induce the negroes to dig for larger quantities
in the adjacent spots. This digging after larger quantities is, as
may be supposed, often very successful; but sometimes it is less
satisfactory, or totally without result, just in the same manner as with
people di^ng for gold. At times numerous larger and smaller
pieces of copal are found close to the surface of the sand, or within
the depth of a few feet; while in other places, after di^ng to the
depth of s to 8 or even lo or more feet, only single pieces, ol- some-
times none at all, are brought to light.
" The secured resin is cleaned by washing and packed in sacks,
to be ready for sale in the markets on the coast. Different varieties
of imequal value being often obtained on the same spot, the resin,
when brought to market, has to be sorted before being sold. It is
classified mostly according to its color, and the price is determined
by weight. The deep-colored quality is generally worth double
the price of the lighter sort. The shape in which the gum is found
is quite variable; it often has the form of an egg, a ball, or a drop,
at other times it looks like a flat, pressed cake, and It is also met
with in sharp-canted pieces. The pieces vary as much in size as in
shape; they are rarely larger than a hen's egg, and there are many
much smaller, others (which, however, seldom occur) are as big as
a man's fist, or even a child's head, weighing three to four pounds
and more. All the pieces of different shape and size have one com-
mon characteristic, namely, that on their surface they are covered
with a thinner or thicker close-sticking, whitish, nearly chalky crust,
which exhibits on many pieces veins or network, while in most
instances it covers the surface like an earthy, powdery coat The
surface of fresh-broken pieces appears conchoidal, with finely radiat-
ing lines in each conchoidal impressbn. The luster is glossy, the
mass is hard and transparent to a certain depth, and where scratched
with a knife or needle it leaves a white powdered stroke. It can
easily be scraped with a knife into powder which, if sprinkled over
red-hot coals, changes instantaneously into thick vapors, at first
with a slight yellow color, with a strong aromatic smell, somewhat
similar to that of incense. Large pieces brought into contact with a
light soon bum up, developing at the same time the above-mentioned
vapors. When chewed it crackles between the teeth without leaving
a noticeable taste."
ov Google
HYDROCARBON COMPOUNCS. 397
" The interior of the Angola copal pieces, when not mhed with
earthy substances, or with remains of bark, is even glossy and trans-
parent; but I have never observed insects in any of the numerous
samples which, partly in Angola and partly at Lisbon, came under
my notice, while in the copal sent to Lisbon from the province of
Mozambique, on the east coast of Tropical Africa, various hymenopi-
terous insects are to be met with. The different colors of the copal
of Angola just described are connected more or less with its avail-
ability for varnishes, etc. Thus the copal dealers distinguish three
sorts, namely, (i) red copal gum (gomma copal vermellia) ; (2) yellow
(g.c. amarella); (3) whitish (g.c. bianca). The red and whitish
sorts furnish the best and finest varnish, and therefore are most in
request and the dearest, while the whitish quality is sold at the
lowest price." '
According to Burton * the present Umit of distribution of the
gum-yielding trees on the east coast is less extensive than that of the
extinct forests which have yielded the true or "ripe" copal, or "san-
darusi," as it is locally called. Every part of the coast from Ras
Gonumi, in south latitude 3, to Ras Delgado, in 10" 41', with a mean
depth of 30 miles inland, may be called the copal coast. The
material b found in red, sandy soil, but is not evenly distributed,
occurring rather in patches, as though produced by isolated trees.
Dr. Kirk considers this gum as a product of trees of the same species
as those at present producing the raw gum called by the natives and
Arabs saTuiarusiza miti or chakazi; that is, the Trachylobium mozam-
bicense Peters. The gum when dug from the soil has superficially
a peculiar pebbled appearance, best described as " goose skin," and
which Burton considered as due to the impress of the sandy grains
in which it had been buried, but which Dr. Kirk regards as due to
the structure of the cellular tissues of the tree. The copal when
freshly dug has, according to this authority, exteriorly no trace of the
goose-skin structure.
As is the case with the New Zealand and West African gums, the
methods of digging are very crude, careless, and desultory. The
' Journal o;' the Linoaean iSociety of Lotidjn, Bolany, IX, 1S66, pp. ayi-ijj.
' Lake Regisnof Central AXrica, II, p. 40J. !>ee also report by Dr. i/L. C Cooke,
on the gums, resins, etc., in tbe India MusetinD, or produced in India. London,
India Museum, 1874.
ovGoo'^lc
39* THE NON-METALUC MINERALS,
diggings are mostly beyond the jurisdiction of Zanzibar, but as this
is the principal port, most of the material is known commercially as
Zanzibar copal.
BIBLIOGRAPHY.
M. C. COOE. Report on Gums, Resins, Oleo-Resins, and Realnoui Products in Um
India Miueuni, or produced in India.
London, lodui Museum, 1S74, pp. 9S-103.
S. F. Peckhau. Report on the Production, Techoolt^y, and Uses of Petroleum and
its ProducU.
Report of the Tenth Cer.sus of the United States, X, 18S0.
This Important report contains a very complete biblic^aphy oa the mbject
up to date of publication.
G. W. GwrPDJ. The Kauri Gum of New Zealand.
U. S. Consular Repons, II, iSSr, p. 141.
R. W. Ravwond. The Natural Coke of Chesterfield County, Virginia.
Transactions of the American Institute of Mining Engineers, XI, tSSi, p. 446.
Edwaxd Orton. a Source of the Bituminous Matter in the Devooiao and Sub-
Carboniferous Black Shales of Ohio.
American Journal of Science, XXIV, 1882, p. 171.
Okaho Silvesti. On the Occurrence of Ciystalliied Paraffin in the Hollow Spaces
of a Basaltic Lava from Patemo, near Mount Etna.
Journal of the Society of Chemical Industry, I, 1883, p. 180.
WiLUAM MoRWSON. The Mineral Albertite »nd the Strathpefter Shales.
Transactions of the Edinburgh Geological Society, V, 1883-188S, p. 34.
A New Mineral Tar in Old Red Sandstme: Ross-shire.
Transactions of the Edinburgh Geological Society, V, 1883-18S8, p. joOl
S. F. Peckham. The Origin ot Bitumens.
American JouiTial of Science, XXVIII, 18S4, p. 105.
Edward Orton. The Trenton Limestone as a Source of Petroleum and Natural
Gas in Obio and Indiami.
Eighth Annual Report U. S. Geological Survey, Pt. i, 18S6-87, pp. 483-661.
J. L. KLEiNScauiDT. Asphalt Deposits in the Fonnation of Coal.
Berg-und Hiittenminnische Zeitung, XL VI, 1SS7, p. 78.
Joseph M. Locke. Gilsonite or Uintaite. A New Vuiety of As{dialtum btai
the Uintah Mountains, Utah.
Transactions of the American Institute of Mining Eogiaeers, XVI, 18S7, p.
163.
A. Rateau. Note sur I'Ozok^rite, ses Gisements, son Exploitation i, Boiyslaw et son
Traiteraent Industrie!.
Annates des Mines, XI, Pt. i, 1887, p. 147. See also Ec^neeiing and Mining
Journal. XLV, r88a, p. 415.
Verarbeitung des galiuschen Erdwachses.
Berg- und HiittenmiUinische Zeitung, XLVII, 1SS8, p. 435.
A. LiVEKSiDGE. Torbanite. — Cannel Coal or Kerosene Shale.
Minerals of New South Wales, 1888, p. r4s.
Uax von Isser. Die Biiumenschatze von Seefeld.
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ov Google
HYDROCARBON COMPOUNDS. 399
L.. BAfitj. Note SUT L'OzokeriU de Borysbw et lea Petroln de Sloboda (Galicie).
Annates de Mines, XIV, iSSS, p. 163. See also Transactbns of the North
of Engbnd Institute of Mining and Mechanical Engineers, XXXVIII, 1S89,
t- IS-
F. V. Greene. Asphalt and its uses.
Transactions of the American Institute of Mining Engineers, XVII, iS&g,
P- 355-
William Moruson. Elateritc: A Mineral Tar in Old Red S^dstone, Ross-shire
Mineralogical Magazine, VIII, May, i83S, October, i8Sg, p. 133.
Hehry Wurti. The Utah Mineral Waxes.
En^eering and Mining JournsJ, XLVIII, Julf 13, 1889, p. 25.
Uintaite a variety of Grahamite.
Engineering and Mining Journal, XLVIII, August 10 18S9, p. 114.
WiLLiAU F. Blake. Wurtzilite from the Uintah Mountains, Utah.
Trsnsactloas of the American Institute of Mining Engineers, XVIII, 18901
P- 497-
' Uintaite, Atbertiie, Grahamite, and Asphaltum described and compared, with
Obaervations on Bitumen and its Compounds.
Transactions of the American Institute (rf Mining Engineers, XVIII, 1S9O)
P- 563-
Hehky Wdrti. WurtiiUte, Prof. Bltke's New Mineral.
Engineering and Mining Journal, XUX, 1890, p. 59,
Bituminous Rock, California.
Tenth Annual Report of the California State Mineralogist, 1S90.
E. W. HiDOARS. Report on the Asphaltum Mine of the Ventura Asphalt Coropanj
Tenth Annual Report of the California State Mineralogist, 1890, p. 763.
• Asphalt and Petroleum in Mexico.
Journal of the Society of Chemical Industry, IX, iSgo, p. 43G.
Geosce Valentine. On a Carbonaceous Mineral or Oil Shale from Brazil; Itt
Formation and Compoution. As a Key to the Origin of Petroleum. '
Proceedings of the South Wales Institute of Engineers, XVII, August 8, 1890^
p. 30.
S. Deutscb. Ozokerite in Galicis.
Jounal of the Iron and Steel Institute, 1S91, p. 311.
Henby Wobtz. A Review of the Chemical Utciature of the Mineral Waxes.
Engineering and Mining Journal, LI, March 38, 1S91, p. 336.
Clarence Lown; H. Booth. Fossil Reuns.
New York, 1891.
Edward Orton. Report on the Occurrence of Petroleum, Natural Gas, and Asphalt
Rock in Western Kentucky.
Geolt^cal Survey of Kentucky, J. R, Proctor, Director, 1891.
BovEBTON Redwood. The Galician Petroleum and Ozokerite Industries.
The Journal of the Society of Chemical Industry, XI, iSgi, p. 93.
E. T. DmiBLE. Note on (he Occurrence of Grahamite in Texas.
Transactions of the American Institute of Mining Engineers, XXI, r893, p. 601.
Henry M. Cadell. Perloleum and Natural Gas; their Geological History and
Production.
Transactions of the Edinburgh Geological Society, VII, Pt. 1, p. 51, 1S93-94.
ov Google
400 THE NON-METMLUC MINERALS.
J. G. GooDCHiLD. Some of the Modes of OrEgin of Oil Shales, with Remarks upon
the Geologiia.! Histoiy of some other Hydraarbon Compouads,
Transactions of the Edinburgh Geologicai Society, VIT, 1895-96, p. I3t.
C. Eg. Bertkand; B. Renault. The Kerosene Shale of New South Wales.
TianMclions of the North of England Institute oE Mining and Uecfaanical
Engineers, XLIV, 1895- P- 7*-
S. F. PEOtHAM, On the Pitch Lake of Trinidad.
American Journal of Scien<x, L, 1S95, p. 33. See alio the Geologiial K
II, 1B95, p. 416.
Wh»t is Bilmnen?
JoimiAl of the FrBDklin Institttte, CXL, 1895, p. 370.
BOVEBTDM Redwood; Georoe L. Holloway. PeEroleum and lU Ptoducta.
3 Vols., London, 1896.
Asphaltum and Bituminous Rock.
Thirteenth Report of the California State Mineralogist, 1896, p. 35.
Otto Lanc. Tiinidad Asphalt.
Transactions of the North of England Itlstitute of Mining and 1
Engineers, XLV, Pt, 3, March, 1896, p. i.
Geoegk H. Eldudge. The UlnUite (Gilionile) Deposits of Utah.
Seventeenth Annual Report, IT. S. Geol. Survey, 1S95-96, Pt. I.
Walixr Mekivale. Barbadoea Manjak.
Engineering and Mining Journal, LXVI, 189S, p. 790.
John Rutherford. Notes on the Albertite of New Brunswick.
Journal of the Fedeiated Canadian Mining Institute, III, 1S98, p. 4a.
I. C. White. Origin of Grabamite.
Bulletin of the Ge<dogical Society of America, X, 1899, pp. 377-384.
Geobce H. Eldridge. The Asphalt and Bituminous Rock Deposits of tbe United
States.
Twenty-second Annual Report, U. S. G. S., 1900-190T, Pt. I, pp. 109-464.
Sbdter^. Die Erdwachs ui>d Petroleum Industrie Boiyalaws, Zeit. fl^ das Berg-
HUtten tind Salinen-wesen im PreusBiscbca Staate, Vol. XLIX, 1901, pp. 87-96.
F. Dahus. Ueber das Voikommen und die Verwendung des Bemsteins, Zdt. flit
piiitiiche Geokigie, Vol. IX, 1901, pp. aoi-aii.
XIV. MISCELLANEOUS.
I. Grindstones; Whetstones; and Hones.
The custom of sharpening edge took on pieces of stone has been
practiced by barbarous and civilized nations ever since the adoption
of cutting implements of any kind, however crude and of whatever
materials.
With the first crude implements, it is safe to say almost any stone
possessing the requisite grit would serve to produce the rough edge
desired. With the improvement in the cutting implement there has,
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MISCELLANEOUS 401
however, been necessitated a correspondii^ improvement in the
character of the sharpening implement as well. Formerly, it may
be safely assumed, every man used that which was most accessible
and could be made to best answer its purpose. . Now the grindstone
and whetstone industry is as well organized as any other branch of
manufacture, and forms no inconsiderable feature of the nation's
trade. Localities are ransacked and material is brought from far
and near, carried long distances, overland or across the ocean, to
the workshops of the manufacturer to be cut into the desired shapes
and sizes, classified and assorted according to quality, and sent abroad
once more to meet the demands of the ever- increasing trade. The
use of the grindstone, it should be noted, is not confined merely to
sharpening edge tools, but, as will be noted later, they are made from
a variety of materials, and of an equal variety of sizes, from the
2-inch wheel of novacuhte, used by jewelers, to a coarse grit monster
of over 2 tons weight for the grinding of rough castings in machine
shops, or wood pulp in paper manufacture.
A stone to be suitable for grinding purposes must possess a fine
and even grain, free from all hard spots and inequalities of any kind.
It is essential, too, that the various particles of which it is composed
be cemented together with just sufficient tenacity to impart the
necessary strength to the stone, and yet allow them to crumble away
when exposed to friction, thus continually presenting fresh sharp
grains and surfaces to act upon the material being ground. Simple
as these essential qualities may seem they are in reality but rarely
met with in perfection, and the majority of grindstones now on the
market are quarried from a comparatively limited number of sources.
If the stone be too friable it wears away too rapidly, and the grind-
ing done is coarse and uneven; a sharp edge or polbh b unobtainable
If too hard it glazes and loses its cutting qualities, or cuts so slowly
as to be no longer desirable. If, moreover, the particles composing
the stone adhere with too little tenacity, the stone, particularly if it
be a large one, such as is used for grinding castings, is liable to burst,
perhaps to the serious injury of workmen and machinery. ^
The requisite qualities as above enumerated are found mainly in
those stones that have originated as sandy deposits on sea bottoms
and have undergone little if any metamorphism — in other words, in
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4oa THE NON'METALUC MINERALS.
sandstones. For some particular reason, or rather owing to certain
peculiar conditions, although sandstones were formed throughout a
great number of periods in the earth's history, those formed during
the Carboniferous age seem best adapted fop the purpose, and from
stone found somewhere in this formation are manufactured a large
share of the grindstones now in use.
A majority of the grindstones now found in the markets of the
United States are made from sandstones quarried from the Upper,
Middle, and Lower Carboniferous formations of Ohio, Michigan,
Nova Scotia, New Brunswick, England or Scotland. A few are, o-
bave been, made from stone from Missouri and Kentucky. The
Ohio stones are obtained nearly altogether from quarries in the sub-
Carboniferous sandstones at or near Berea, Amherst, Bedford, Con-
stitution, Massillon, Marietta, Independence, and Euclid. Few if
any of the quarries are worked wholly for grindstones, but in the
majority of cases the stone is sought for building purposes as well,
and the grindstone output may be merely incidental, certain layers
only being adapted for the latter purpose. This is well illustrated
by the following section, as shown at one of the Amherst quarries
and as described ^ by Professor Orton, the State geologist. The
reader will understand that by section is meant the various layers
exposed in the quarry wall, or that would be passed through in dig-
ging or boring from the surface downward.
At Amherst, then, the stone lies as follows, beginning at the sur-
face-*
Feet.
Drift material (soil, sand, etc.) i to 3
Worthless shell rock 6 to 10
Soft rock used only for grindstones 12
Building stone 3
Bridge stone '. 3
Grindstone 3
Building and grindstone 10
Building stone 4 to 7
Building stone or grindstone la
' Geological Survey of Ohio, V, p, 386,
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MISCELLANEOUS 403
Commenting on the condition of affairs as here displayed, Pro-
fessor Orton says:
"As will be noticed in this section, the different strata are not
applicable aUke to the same purpose, and the uses for which the
different grades of material can be employed depend principally
upon the texture and the hardness of the stone. The softest and
most uniform in texture is especially applicable for certain kinds of
grinding, and is used for grindstones only, and the production of
these forms an imp>ortant part of the quarry industry. In its differ-
ent varieties the material is applicable to all kinds of grinding, and
stones made from it are not only sold throughout this country, but
are exported to nearly all parts of the civilized world. Some of the
finest-grained material b also used in the manufacture of whetstones.
There are various points in the system of the Berea grit where the
stone is adapted to this use, but such a manufacture is best carried
on when joined with a lai^e interest in quarrying, so that the small
amount of suitable material can be selected; and thus it happens that
only at Amherst and at Berea are whetstones manufactured in large
quantities."
Below are given in brief outline the sources and main characteiv
istics of the principal grindstones now in the market, beginning with
those of the United States. In speaking of the texture of any stone,
that of Berea has been taken as the standard. This is the stone most
used for grinding cutting tools, such as axes and scythes. It must
be remarked here that the term Berea grit is applied not merely to
the stone from the immediate vicinity of the town of Berea, but is
rather a general name applied to this particular subdivision of the
sub-Carboniferous formation of Ohio and extending over a wide
field.
Berea. — Medium fine; blue gray, light yellowish, or nearly white.
For edge tools in general ; the finer varieties also used for whetstones.
Amherst. — Medium fine, like the Berea, being a part of the same
formation. Light gray, with small rust-colored spots due to iron
oxides. For grindstones and whetstones for edge tools in general;
the softer varieties for saws.
Independence. — Similar to the Amherst, and especially adapted for
the manufacture of large grindstones for diy grinding; stones said
not to glaze when used for this purpose.
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404 THE NON-METALLIC MINERALS.
Bedford. — Rather coarser, though of even texture and filled with
brown spots of iron oxide. Especially adapted for grinding springs.
Euclid. — Fine, light bluish gray; for wet grinding edge tools.
Massillon. — Medium to rather coarse; the microscope shows it
to be an a^regate of rounded, colorless grains of quartz, with little,
if any, cementing material. Not so finely compacted as the last, and
small fragments can be readily broken from the sharp edges by means
of the thumb and fingers. Color, light yellowish or pinkish; for edge
toob, springs, files, and nail-cutters' face stones, but mainly for the
dry grinding of castings. •
Constitulion. — Medium; light gray and rather more friable than
the last. A variety of tenures, however, and all kinds of grits for
wet grinding are furnished.
Huron, Michtgati. — Fine; uniform blue-gray color, with numer-
ous flecks of silvery mica. Smells stroi^Iy of clay when breathed
upon. For wet grinding of edge toob; produces a fine edge.
The Joggins, Nova Scolia. — Fine gray; of uniform texture; used
for wet grinding all kinds of edge toob ; the laige stones for grinding
springs, sad irons, and hinges; extensively exported to the United
States.
Bay 0} Chaleur, New Brunswick. — Fine dark bluish gray; of
firm texture; smelb strongly of clay when breathed upon. Resem-
bles the stone of Huron, Michigan, but contains less mica. Used in
the manufacture of table cutlery; also machinbts' toob and edge toob
in general.
Newcastle, England. — Light gray and yellowish; with a sharp
grit; rather friable, and texture somewhat coarser than that of the
Berea stone, which it otherwise somewhat resembles. The finer
grades used for grinding saws and the coarser and harder ones for
sad irons, springs, pulleys, shafting, for bead and face stones in nail
work, and for dry grinding of castings; also used by glass cutters.
Wickersly, England. — A dull, brownish or yellowish, somewhat
micaceous stone of medium texture and rather soft. For grinding
saws, squares, beveb, and cutlers' work in general.
Liverpool, or Melling, England. — Dull reddish; a somewhat
loosely compacted aggregate of siliceous sand, so friable that the sharp
angles are easily crumbled away by the thumb and fingers. A very
sharp grit, used for saws and edge tools, particularly axes in ship-yards.
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PLATE XXXV.
Microslructure of Mira Schist used in making Hones. Fig. i
Fig. 7. Cm paiallel with Grain. The enlargement is the :
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MISCELLANEOUS. .|oS
Craigleitk, Scotland. — Fine-grained and nearly white. A very
pure siliceous sandstone with a sharp grit. Said to be the best stone
known for glass cutting, though the Newcastle, Warrington, and
Yorkshire grits are also used for a similar purpose.
For whetstones the same qualities are essential as for grindstones,
though as a rule the whetstones are designed for a finer class of
work, and hence a finer grade of material is utilized. For sharpening
scythes and other coarse cutting took, however, the same stone is
used as for grindstones, the same quarry producing stone for build-
ing, grindstones, and whetstones, as above noted. The so-called
Hindostan, or Orange stone, from Orange County, Indiana, is a very
fine-grained siliceous sandstone of remarkably sharp and uniform
grit, and which for carvers and kitchen implements is unexcelled.
The so-called Labrador stone is also a sandstone of a dark blue-gray
color and of less sharp grit than tliat just mentioned. Many scythe-
stones like " Indian Pond " " Chocolate," " Farmers' Choice,"
"Black Diamond," "Vermont Quinebaug," and the "Lamoille,"
are fine-grained mica schists from New Hampshire and Vermont
quarries. These as a rule are very fine-grained schistose dark-gray
rocks, sometimes of a light chocolate color on a freshly fractured
surface. The microscope shows them to consist of a compact and
slightly schistose aggregate of quartz and mica in which are fre-
quently included very abundant small octahedral crystals of mag-
netic iron and sometimes garnets. (See Plate XXXV ,) So abundant
are these magnetic granules in some of these rocks, especially those
of Grafton County, New Hampshire, as to constitute an important
feature, and it is doubtless in part to them that the stone owes its
excellent abrasive qualities. Magnetite, it will be remembered, has
a hardness of about 6.5 of the scale, and constitutes a veiy consider-
able proportion of the ordinary emeiy of commerce. We have here,
then, what is almost a natural equivalent of the artificial emery stone,
the compact groundmass of quartz and mica serving as a binding
material for the magnetite grains while they perform their work in
wearing away the implement being ground. A part of the abrading
quality of these stones is, however, due to the abundant quartz and
mica scales and their peculiar arrangement m relation to one
another.
The well-known Water of Ayr, Scotch hone, or snake stone, as
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4o6
THE NON-METALLIC MINERALS.
it is variously called, h also a very compact schist. It is said to
come from Dalmour, in Ayrshire, Scotland.
The name novaculite is applied to a very fine-grained a.nd com-
pact rock consisting almost wholly of cbalcedonic silica, and which,
owing to the fineness of its grit, is used only in the finer kinds of work,
as in sharpening razors, knives, and the tools of engravers, car-
penters, and other artisans. The true novaculites are at present
quarried in America only in Montgomery, Saline, Hot Spring, and
Garland counties, in Arkansas, and are known commercially as the
■ Washita (or Ouachita, as the name is properly spelled) and Arkansas
stones. Both varieties are nearly pure silica, the Ouachita being
often of a yellowish or nisty red tint, and the Arkansas of a puie
snow whiteness, the latter variety being also the hardest, most com-
pact, and highest priced. The analyses given below show the average
composition of the two varieties:
Al,6.'
F=,0,
CaO-
MgO.
K,0 .
NSjO
According to Griswold stone suitable for the manufacture of
whetstones occurs in quantity in two distinct horizons in the Arkansas
novaculite series of rocks, both of which are now being worked.
The principal quarries are in the massive white beds of the Hot
Springs region, the material being mainly of the fine, compact white
Arkansas type. Within a limited region, northeast of Hot Springs,
the stone becomes more porous, owing in part to the existence of a
larger number of the rhomboidal cavities, and passes over to the
Ouschita type.
The microscopic structure of the Arkansas novaculite is shown
in Plate XXXVIIjFig, i, the large white areas being angular granules
of quartz.
Owen regarded the Arkansas novaculites as belonging to the age
of (he millstone grit formation; that is, to the lower part of the
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Fig. I. — Quarry in MLca Schist used in making Whetslones, Pike Manufacturing Co.
Fig. ». — Quarry in Novaculiie, Arkansas. Pike Manufaciuring Co.
PLATE XXXVI.
[Fating page 406.]
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MISCELLANEOUS. ' 407
Carboniferous, and considered them as a sandstone metamorphosed
and freed from impurities by the action of hot alkaline waters. State
Geologist Branner, however, regards the finer grade of novaculite
as a metamorphosed chert, a conclusion more in accordance with
the microscopic structure of the rock, which is more that of chalce-
dony than of an altered sandstone. Griswold, on the other hand,
regards the novaculite as a product of sedimentation of a fine siliceous
silt, and of Lower Silurian age,' while Rutley * considers it as a
product of chemical replacement by silica of the calcareous material
of dobmite or dolomitic limestone beds.
The view in quarry of the Pike Manufacturing Co., Plate XXXVI,
shows the novaculite beds dipping 60° to the southeast, the bed of
good stone being some 12 or 15 feet in thickness. The rock is every-
where badly jointed, in one case mentioned by Griswold as many as
six different systems being developed in a single quany. The natural
result is that pieces of only very moderate dimensions are obtainable
even under the most favorable of circumstances. Fine veins of
quartz intersecting the rock in various directions increase the dif-
ficulty of getting homogeneous material and thereby increase the
cost of the output
llie Arkansas stone is now used for many purposes by i>rtisans
of all classes, by wood-carvers, jewelers, manufacturer^ of fine
machinery and metal work, and by dentists in variouj, forms of
files and points. Dentists use particularly the " knife-blade," a
very thin, broad slip of stone, triangular in section, with one short
side, the other two forming a thin edge as they come together. They
are used for filing between the teeth. Car\'ers use wedge-shaped, flat,
square, triangular, diamond -shaped, rounded, and bevel-edged files
for finishing their work. Jewelers, especially manufacturing jewel-
ers and watchmakers, use all these forms of files and also points.
These last are sometimes made the size of a leadpencil, having a
cone-shaped raid, and are about 3 inches long and \ inch square,
tapering to a point, lliey are used chiefly in manufacturing watches
to enlarge jewel-holes.
' See Whetstones and Novaculites, by L. S. Griswold, Annual Report of the Goo-
logical Survey of Arkansas, III, 1891. This report conuins a very full discussioB of
the Arkansas novaculite in all its bearings.
' Quarterly Journal of the Geological Society d London, I., 1894, p. 377-
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4o8
THE NON-METALUC MINERALS.
Wheels of various thicknesses and diameter are also made from
Arkansas stone. Such are used chiefly by jewelers and dentists.
The difficulty of obtaining pieces of clear stone large enough
for wheels several inches in diameter makes the price ver>' high,
and the diiSculty of cutting out a circular form increases
the cost. Wheels are quoted at from $i.io to $2.20 an inch of
diameter.
Fragments of the Arkansas stone are saved at the factories, and
now and then sent away to be ground for polishing powder. In the
manufacture of this powder millstones are worn out so rapidly that
the process is rather expensive, but as waste stone is utilized, the
powder can be sold by the barrel at 10 cents a pound. It makes a
veiy fine, pure white powder of sharp grit, suitable for all kinds of
polishing work; it b known as "Arkansas powder."
The so-called Turkish oilstone from Smyrna, in Asia Minor, is
both in structure and abrasive qualities quite similar to the Arkansas
novaculites. It, however, is of a drab color and carries an appre-
ciable amount of free calcium carbonate and other impurities, as
shown by the analysis given below, as quoted by Griswold;
TOBKEY-SrONE.
c..u.„„.
Par Cent.
71.00
3-33
'3-33
'0-33
According to Renard,^ the celebrated Be^ian razor hone quarried
at Lierreux, Sart, Salm-Chateau, Bihau, and Recht is a damourite
slate containing innumerable garnets, more than 100,000 in a cubic
millimeter. Like the Ratisbon hone, this occurs in the form of thin,
yellowish bands, some 6 centimeters wide (2| inches) in a blue-gray
slate (phyllade). The bands are essentially parallel with one
another and with the grain of the slate, into which they at times
gradually merge. The chemical composition of a sample from
Recht is given on the next page. The microscopic structure of the
stone as described and figured by Renard is essentially the same
as that of the Ratisbon stone in the collections of the U. S. Natbnal
' Mfoioires Couronnts et M&no[rca des Savunts Etningcn de L' Academic Royll
des Sdencet, etc., Belgique, 1S7S, pp. 1-44.
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PLATE XXXVII .
Uicrost rue lure of (i) Arkansas Novaculite and (2) Ratisbon Rawr Hone. The Dark
Bodies in (2) are Garnets.
The enlargement is the same in both cases.
[U, S. National Museum,] | . OoOqIc
[Facing pagt 408.] '^
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MISCELLANEOUS.
coiiPOErnoH o
Campodtion,
Silica (SiO,)
TiUinic oxide (TiO,)
Alumina (Al,0,)
Ferric iron (Fe.O,)
Ferrous iron (FeO)
Manganese oxide (MnO).
Magnesia (MgO)
Lime (CaO)
Soda (Na,0)
Potash (K,0)
Water (H,0)
Catbon dioxide (CO,) . . . .
Pbo^boric acid (PA). . .
Sulphur (S)
Organic matter
Toul
Museum (See Plate XXXVIII, Fig. 2), and the stones are practi-
cally identical in color and texture as well.
The cutting property of the stone would appear to be due to
the presence of the small garnets above noted.
The so-called holystone is but a fine, close-grained sandstone
of the same nature of that used in grind and whet stones. The
greater part of those made in this country are from the Berea sand-
stone of Ohio, though some are said to be imported from Germany.
They are used mainly on shipboard.
2. mU-STONES.
The use of stone in the form of flat circular disks for grinding
grain has fallen away greatly since the introduction of the steel-
roller process. Nevertheless, the smaller mills, and particularly the
'grist mills" of country districts, are still utilizing the old-time ma-
terial. Two types of stone are in conunon use for this purpose,
the one a siliceous conglomerate of quite variable structure, and
the other a vesicular chalcedonic rock commonly known as buhr-
stone.
Material of the first mentioned type is found in the United States
near Esopus Creek in Oneida county, New York, the beds belonging
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4IO THE NON-METALLIC MINERALS.
to the Oneida conglomerate division of the Niagara (Upper Silurian)
period. The" rock consists of rounded and subangular pebbles of
quartz sometimes 2 cm. in diameter, compactly embedded in a. fine
siliceous matrix forming an exceedingly tough and hard mass w}th at
the same time a sufficiently sharp grit to make it available for grind-
ing pur[>oses. The celebrated German millstone from Zittau is of
a somewhat similar nature, though the large quartz pebbles are
in this case embedded in a more sandy matrix. Buhrstone, as is
noted above, is a chalcedonic cellular rock commonly r^arded as a
silicious replacement of limestone, and containing numerous casts of
shells, and other cavities. The rock is very tough, breaking with a
sharp splintery fracture. It is admirably adapted for grinding
grain, and has been so used from a very early period. That best
known comes from Tertiary beds near Paris, in France. A good
grade of material of similar nature is stated to exist in large quan-
tities along the Savannah River, in Georgia. Though occurring
abundantly it is not found in a continuous stratum, but rather in
sporadic masses in the marl beds.
3. PUMICE.
The material to which the name pumice is commonly given is
a form of glassy volcanic rock, which, by the expansion of its included
moisture while in a molten condition, has become, like a well-raised
loaf, filled with air cavities or vesicles. The cutting or abrasive
quality of the material is due to the thin partitions of glass compos-
ing the walls between these vesicles. Any variety of volcanic rock,
flowing out upon the surface is likely to assume the vesicular con-
dition known as pumiceous, but only certain acid varieties known as
liparites seem to possess just the right degree of viscosity and amount
of moisture to produce a desirable pumice, and in this rock only in
exceptional circumstances. Almost the entire commercial supply of
pumice is now brought from the Lipari Islands, a group of volcanoes
north of Sicily, in the Mediterranean Sea, where it is dug from the
loose tufi forming the cone of the volcano. The material is usually
brought over in bulk and sold in small pieces in the drug and paint
shops, or ground and bolted to various degress of fineness and sold
like emery and other abrasive materials. At times an inferior grade
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Fio. 1. — Bed of Pumice Dusl, Kansas.
{Fromaphotograph.J
9. — Quarry of Quartz Sand, Oltans, Iltinots.
[From a photo(^ph.]
PLATE XXXVIir.
[Facing page 410.]
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MISCELLANEOUS.
o£ pumice has been produced from volcanic flows near Lake Merced,
in California. Id Harlan County, Nebraska, and adjacent portions
of Kansas, as well as in many other of the States and Territories
farther west, have been found extensive beds of a fine, white powder,
which was first shown by the present writer ' to be pumiceous dust,
drifted an unknown distance by wind currents and finally deposited
in the still waters of a lake. Through a mistaken notion regarding
its origin this material was first described in Nebraska as geyserite.
So far as the writer is aware, these natural pumice powders have
thus far been exploited only for polishing purposes and as a cleansing
or scouring agent in soap, .^s the material exists in almost inex-
haustible quantities, it would seem that a wider scope of usefulness
might yet be discovered.
The analyses given below show (I) the composition of the pumice
dust of Harlan, Orleans County, Nebraska,* and (11) a pumice from
Capo di Costagna, Lipari Islands:
ComUtuenlii.
I.
IL
69.1.
} ■7-64
0.86
O.J4
6.64
1.69
405
T7 10
I
«7
i's
29
73
.00..4
99... 1
1
The Lipari pumice, in commerce is classified as follows —
^055* (large size), correnti (medium), and pezzani (small); the large
and middle sizes are subdivided into lisconi (fiat and roUmdi (round).
The lisconi are filamentous, that is, the vesicles are elongated all
in one direction, and break less easily than the rotondi. The
' See On Deposits of Volcanic Dust in Southwestern Nebraska (Proceedings U. S.
National Museum, VTII, iSSs, p. 99), and Notes on the Composition of Certain P'io-
cene Sandstones from Montana and Idaho (American |oumaI of Science, XXXII,
1336, p. 199).
' Rocks, Rock wealbeiing, and Soils, p. 350.
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41 a THE NON-METALUC MINERALS.
lisconi and rolondi are again subdivided into white, black, and
uncertain, according to their color.
The price, it is stated, varies according to the quality from 50 to
2,000 lire the ton. The common price tor the assorted is 350 to 500
lire the ton. As much as 5,000 tons a year are exported. The best
pumice is that of Campo Bianco. It is also obt^ed at Perera, but
it is in small quantity and was produced at the eruption of the Forgia
Vecchia. It is a first class gray pumice and fetches from 600 to
750 lire the ton, and does not so easily break as the Campo Bianco.
Also at Vulcano a gray pumice b found, but the presence of included
crystals renders it useless for commercial purposes. At Castagna a
commoner pumice is obtained called Alessandrina, of which brkk-
shaped pieces are made and used for smoothing oil-cloth.^
According to the Engineering and Mining Journal • a merchant-
able pumice has recently been found in Miller County, Idaho, but
the demands for material of this nature is likely to be lessened by the
putting upon the market of a German arti&cial product. In 1897
some 1700 tons of pumice were mined near Black Rock, Millard
County, Utah.
Ground and bolted pumice is quoted as worth from $25 to $35 a
ton according to quality.
4. ROTTENSTONE.
The name rottenstone has been given to the residual product from
the decay of silico-aluminous limestones. Percolating carbonated
waters remove the lime carbonate from these stones, leaving the
insoluble residue behind in the form of a soft, friable, earthy mass
of a light gray or brownish color, which forms a cheap and fairly
satisfactory polisher for many metak.
The chemical compositon of rottenstone, as may well be imagined
from what has been said re^rding its method of origin, is quite
variable, though alumina is always the predominating constituent.
Analyses as given, are of doubtful value; they show: Alumina,
80 to 85 per cent; silica, 4 to 15 per cent; 5 to 10 per cent of carbon,
' The South Italian Volcanoes, by H, J, Johnston-La vis, Naples. F. Furchbcim,
1B91, pp. 67-71.
' Volume LXIV, July 24, 1B97, p. 91,
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MISCELLANEOUS: 413
and equal amounts of iron oxides and varying small quantities of
lime. The material has little commercial value.
5. ICADSTONES.
The fallacy of the madstone dates well back into the dark ages,
and, struige as it may seem, continues down to the present day.
Not longer ago than December, 1898, the Washington newspapers
chronicled the sale for $450 of a madstone in Loudoun County,
Virginia, and from year to year very many letters are received by
the Smithsonian authorities making inquiries regarding such, or
possibly offering one for sale at fabulous prices.
So far as the writer is able to learn, either from literature or from
personal examination, stones of this class are almost invariably of an
aluminous or clayey nature, and their supposed virtue is due wholly
to their avidity for moisture — their capacity for absorption, which
causes them to adhere to any wet surface, as the tongue or to a wound,
until saturated, when they will drop away. It should not be neces-
sary to state, at this late day, that their curative powers are purely
imaginary. The ancient bezoar stone, used in extracting or expelling
poisons, consisted of a calculus or concretion found in the intestines
of the wild goat of northern India.'
6. HOLDING SAND.
For the purpose of making molds for metallic casts, a fine, homo-
geneous argillaceous sand is commonly employed.
The physical qualities which go to make up a molding sand con-
sist, according to Nason,' of elasticity, strength, and a certain degree
of fineness. It must be plastic in order to be molded around the pat-
tern; it must have sufficient strength to stand when unsupported by
the pattern, and to resist the impact of the mohen metal when poured
into the mold. Too much clay and iron present in the sand will
' W J HoSmut, Folic Medicine of the Pennaylvonia Germans, Proceedings of the
American Philosophical Society, XXVI, 1889, p. 337.
* Wattj-aertBth AmnMl Beport of the R^cots State Museum of Nen Yorit, 1S93,
p.469'
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4i4
THE NON-METAUIC MINERALS.
cause the mold to shrink and crack under the intense heat; too little
will cause it to dry and crumple, if not to entirely collapse.
The peculiar virtues of molding sand, as outlined above, are
ascribed to the fact that each of the sand grains is coated with a thin
film of clay.
The accompanying table will serve to show the varying chemical
character of sands thus employed, though, according to authorities
quoted by Crookes and ROhrig,^ the quality of the sand for mold-
ing depends less on its chemical composition than on its physical
properties, namely, whether the grains are round, angular, scaly, ^tc,
and whether they are of uniform size. The adhesiveness is deperjdent
not alone on the quantity of clay, but upon the ai^larity of the
grains, and by a mixture of smaller and larger grains. Reinhardt
states that to the naked eye, a good sand should consist of particles
seemingly uniform in size, with a sharp feel to the touch. When
strewn upon dark paper it should show no dust, and when moistened
with from lo to 20 per cent of water it must be capable of being formed
into balls without becoming pulpy or being too easily crushed.
ConMituenu.
I.
11.
III.
IV.
VI.
VII.
VII.
P
Traces
91.907
S-68J
a.i;7
0-415
91-913
5-850
1. 149
Traces
90.61S
6.667
,.708
Traces
79.0J
0.71
4.58
86.68
9»3
87.6
0.96
9o-»S
4.10
5-5'
OJ3
AL<5;: :::::;::
Fe,0,andFeO..
CaO
%p':::.\'::::
99-996
100.181
>oo.o,.
100.000
100.43
100.19
99.86
.oao9
Of the above No. i is from Charlottenburg, Germany, No. II, a
sand employed tor bronze castings in Paris foundries; No. Ill, sand
from Manchester, England; No. IV, from near Stromberg; No. V,
from Ikenburg, in the Hartz Mountains; No. VI, from Sheffield,
England; No. VII, from Birmingham, England, and No. VIII, from
Ltinebui^,
The sand from Ilsenburg, the composition of which is given -in
' A Practical Treatise on Metallurgy, II, p. 636.
ov Google
MISCELLANEOUS.
41S
column 5, is stated ' to be prepared by mixing " common argillaceous
sand, sand found in alluvial deposits, and sand from solid sandstone."
In preparation the first two are carefully heated to dehydrate the clay
and then mixed, e^qual proportions of each with the same amount of
sandstone. The mixture is then ground and bolted, the product
being as fine as flour and capable or receiving the most delicate im-
pressions.
According to D. H. Truesdale,* the four essential qualities in
molding sand are, in the order of their importance, (i) refractoriness,
(2) porosity, (3) fineness, and (4) bond. - These qualities are depend-
ent mainly upon the varying properties of siliceous sand and clay,
the refractory nature being governed by the absence of such fiuxtng
constituents as calcium cabonate, the alkalies, or of iron oxides.
Since in nature it is not always possible to obtain the admixture of
just the right proportion, artificial mixtures are often resorted to, as
mentioned above. Ferguson gives ' the following analyses of
molding sand in actual use in his foundries:
CofUtituenU.
No. t. Pine
Suidfor
SmpWork.
Uuhine
C«tiDg^
Kg4.fprHe«Tr
3U
Trace.
Trace.
84.86
7-03
i.tS
l:^
No estimate.
Trace.
Trace.
8.31
'I
Noii^
No estimate.
Trace.
Trace.
79-81
4-44
»39
1:11
Combined water
Calcium carbonate . . .
Oigank matter
Trace.
Total
too.o.
98-35
97.98
99.37
Sands containing lime or alkalies, that is those containing free
calcite or feldspathic granules, are sometimes liable to fusion in the
case of heavy castings. It is customary in such cases to coat the
surface of the mold with graphite.
The following table, fromta recent report of the State Geologist
' Percy's Metallurgy, i86l, p. 139.
•The Iron Trade Review, October, 1897, p. 14.
'Iron Age, LX, December, 1897, p. 16.
J, Google
THE NON-METALUC MINERALS.
SSI
s%
. . . ??^
3, 2 S 3 1
if
-^^u
"ts^
Mjff
™So4d
sissi-iaiii s iiiiiiiii
■npaqpy A^j
\ltimnS"^iTMi^i
1
i
•iiii.i-iii%-i rs s 8 '»""•'
«
= So So So „<. O « „0 S.i'o O ~;S.
i
ISog^'S.^oo-, o -^S^.KoooS,
i
?!-op;|:^j:^:|j^^|5
%
ffSb oS^OOO 0 o„«,8S„coS
s
s
o~o o "'^^- oi "^^ **- - oo"^"-". "^
-
o^oo^.^oooo ^ Boooo^^^^
•
ojooo|oooo.|o.ooo^^^o
1
i
1
-.s
IP
III
Pi
llll
iTi\
E
J
J
E
•
:
;
■s It-
a S|«
lill
II4J
Hi
•g
!
J
f
1
1
■g
11
J
0 Got>^lc
MiSCELLMNEOUS. 417
of New Jersey,^ will show the physical condition of some well-known
molding sands:
Sands suitable for ordinary castings are widespread, though the
finer grades are often brought considerable dbtances, some of those
used in bronze casting in America being imported from Europe.
In the United States the beds are alluvial deposits of slight thickness.
Large areas occur in New York State, in counties extending from the
Adirondacks to New Jersey, At date of writing a very considerable
proportion of the material used in the eastern United States is dug
in Selkirk, Albany County, New York, and central and southern
New Jersey.
The Selkirk molding sand is of a yellow-brown color, showing
under the microscope angular and irregular rounded particles rarely
more than 0.25 ram. in diameter, interspersed with finely pulvprulent
matter which can only be designated as clay. The yellow-brown
color of the sand is due to the thin film of iron oxide which coats the
larger granules. When this film is removed by treatment with dilute
hydrochloric acid, the constituent minerals are readily recognized
as consisting mainly of quartz and feldspar fragments (both ortho-
clase and a plagkx^ase variety), occasional granules of magnetic
iron oxide, and irregularly outlined scales of kaolin, together with
dust-like material too finely comminuted for accurate determination.
Many of the larger granules are white and opaque, being presum-
ably feldspar in transition stages toward kaolin. An occasional flake
of hornblende is present.
The sands occur in beds varying from 6 inches to 3 feet or even
5 feet in thickness. They immediately underlie the surface soil and
overlie coarser, well-stratified sand beds more nearly allied to quick-
sands.
In gathering the sands for market, a section of land i or 2 rods
in width is stripped of its overlying soil down to the sand, which is
then dug up and carried away. When the area thus exposed is
exhausted, a like area immediately adjoining is stripped, the soil from
the second being dumped into the first excavatioD. By this method
' Ann. Rept. of State Geologist of Nen Jersey, 1904, pp. 187-144. See also B
■Dd RSsen, On Foundry Sands, Rept. Geological Survey of MichigaD, 1907.
ov Google
4l8 THE NON-METMLUC MINERALS.
the fidd, whei finally stripped of itsi molding sand, is ready again
for cultivation.
It is estimated that a bed of sand 6 inches in thickness will yield
T,ooo tons an acre. 'I'he royalty paid the farmers from whose land
it is taken varies from $ to 25 cents a ton. Some 60,000 to 80,000
tons are shipped annually from Albany Coimty alone.
The term green-sand ^ is applied to the argillaceous molding
sands in an undried state, and which is employed in its native state,
new and damp. The term dry sand is used in contradistinction, to
indicate a sand that must be dried by heat before being fit for use.
The dry sand is stated to be firmer and better adapted than the
green for molding pipes, columns, shafts, and other long bodies of
cylindrical form.
In England good noolding sands are obtained from the Lower
Mottled Sands of the Bunter (Trias) beds and from tho:>e of the
Thanet (Lower Eocraie).
BIBUOGRAPHY
Waltbk Bagshaw. On the Mechanical Treatment of Molding Sand.
Inslilule of Mechanical Engineering Proceedings, 1S91, pp. 94-107.
F. L. Nason. Economic Geology of Albany CouMv.
N. Y. Sl&te Geologist, I3lh Ann. Report, 1894, pp. 363, 3S7.
Edwin C. Eckel. Molding Sand: lis Uses, Properties, and Occurrence.
N. Y. State Geologist, 31st Ann. Report, 1903, pp. r9i-r96.
H. B. KcuuEL. Report upon Some Molding Sands of New Jersey.
Geological Survey of New Jersey, Ann. Rept. at State Geobgist for the year
'904, pp. 187-244-
HUHUCB RiES and F. L. Gaixup. Report on the Molding Sands of Wiaconan.
WiioKUin Geol. and Nal. Hist. Survey, Bulletin No. i;, 1906, pp. 197-147.
7. SAND FOR UORTASS AND CEUENTS.
Enormous quantities of siliceous sand are annually used in the
preparation of mortar for plastering and bricklaying, or in cements.
As a rule no great amount of discrimination is shown in the selectnn
of the material, the matters of locality and cheapness being p«-haps
the controlling items. It by no means follows, however, that care
' Tint must not be confounded with the Greensand Marl, or Glaticonitic Sand
used for fertilizing purpose* (see p. 420).
, Gooj^lc
MISCELLANEOUS. 419
is not necessary or desirable. It is stated that the best grades are
those ia which the granules present a considerable diversity of size
and are sharply angular. A standard adopted for use in construc-
tion on one of the leading railroads demanded that 54 per cent
should pass a 24-mesb sieve, and 11 per cent a 50-mesh. Clay in
amounts as high as 1 2 per cent is not in all cases objectionable.
The sources of such sand are almost infinite. River beds, sea
beaches, and sand banks wherever found are the common resorts.
8. SAND FOR GLASS UAKIMG.
Quartz sand is extensively used in glass making. For this
purpose a fairly pure quartz sand is needed, though naturally the
common grades of bottle glass demand a much less pure material
than do the higher grades of flint, or plate glass. It is stated ^ that,
aside from purity, the matter of size and shape of the individual
sand grains are matters of primary importance. By some it is
contended that in the best grades the grains are sharply angular,
rather than rounded. Uniformity, and in sizes varying from 0.15
mm. to 0.60 mm., seem most desirable. Sands containing a majority
of the grains less than 0.136 mm, in diameter (i.e., passing a 130-
mesh sieve) " bum out," and produce less glass per unit than those
which are coarser. The finer grains have a tendency to settle to the
bottom of the batch, thus preventing a homogeneous mixture. Sand
in which the grains are more than 0.64 nun. in diameter (30-mesh)
fuse slowly, thus diminishing the daily output of the furnace and
incidentally mcreasing the cost
The chemical composition of some glass sands from Southern
New Jersey and Pennsylvania, and others in use by manufacturers
Is shown in the table on page 420.
The impurities in these sands are due as a rule to mechanically
entangled bits of mica, magnetite, ilmenite, or rulite, feldsp^, etc.,
which can often be largely eliminated by washing,
Lai^e quantities of sand suitable for glass making are attained
either from beds of loose sand or by crushing a loosely consolidated
' Annual Report State Geologist of New Jersey, 1906.
ov Google
THE NON-METALLIC MINERALS.
■
,
3
4
s
6
,
S
SiO,...
Fe.O...
99
oos8
3751
»3i
99
61
0047
141
0543
i
99
<.io8
355
3113
009
023
19
99
71
0017
i»3
0147
007
008
'34
98. 94
0.0036
e.30
99-"
0.003
0.30
0.008
99- 5S
0.21
Cad...
MgO..
0.13
o.w>
Trace.
}o.oo.
0.50
No, 3 used only in cheaper grades of glass, aa for beer bottle*.
No. 4 used for best grades of flint glass.
Nos. 5 and 6 sands used by the Pittsburg Plate Glass Co.
KoL ; and 8 undi used by the American Window Glau Co.
sandstone in Illinois, Indiana, Maryland, Massachusetts, Missouri,
New Jersey, New York, Ohio, Pennsylvania, and West Vii^nia.
Doubtless equally good sands may be found in other localities, but
the co3t of fuel is the controlling item and a large share of the
furnaces are in regions of cheap fuel or with peculiarly favorable
facilities for transportation or for market The price varies from
$0.90 to $1.50 a ton.
9. GLAUCONITIC SAND.
The names greensand, greensand maxl, and glauconitic mail
are given to a dull greenish, loosely coherent arenaceous deposit,
consisting essentially of the hydrous silicate of iron and potassium,
but variously contaminated with particles of quartz and siliceous
minerals, oxides of iron, clay, rock fragments, and particles of shells.
The table on page 421 from the Annual Report of the State
Geologist of New Jersey wiD serve to show the varying composition
of the materinL
The most extensive and best-known deposits in the United States
are included in what are known as the Upper, Middle, and Lower
marl beds of the Cretaceous formations in southeastern New Jers^,
though it b also known to occur in beds of Eocene age in Maryland,
Virginia, North and South Carolina, and Alabama. Though appar-
ently limited to beds of no particular age, it seems, nevertheless,
most abundant, both in America and in Europe, in the Mesozoic
formations.
ov Google
MISCELLANEOUS.
COHPOSttlOH OF GLAUOOHTnC tIARLS.
CoDttitnaiu.
..
II.
„.
IV-
V.
VI,
34-50
t.S4
il
C.S8
4S-S0
3-79
'-5t
S.80
34.50
IS -40
O.llJ
0.41
0.49
8:tj
0.50
0.34
47 -so
1:3
l:S
13-57
6.8?
3-73
44
6S
97
97
90
04
97
49.68
4.98
y,
28.71
5-54
99-43
99.18
99-37
99-58
,1
99.69
Origin. — ^The glauconitic beds are believed to have been formed ■
in comparatively shallow waters during periods of slow sedimentation
along coasts receiving debris from continental slopes and of a nature
such as would result from the breaking down of feldspathic rocks.
In New Jersey the beds vary from 30 to 60 feet in thickness, but
the glauconitic layers are not homogeneously distributed through-
out
Uses. — The material is mined from open pits and used locally
as a fertilizer. The percentages of phosphoric acid, potash, and
lime are too low to warrant transportation for any distance.
10. ROAD-UAKING HATESIALS.
Roadways subject to any considerable amount of traffic demand
almost invariably some sort of stone bedding to prevent their becom-
ing soft or badly cut up and rutted by wheels and hoofs of horses.
Until within a comparatively few years, it has been the general custom
to pave the streets of cities and towns with rectangular blocks of
granite, trap, or other hard rock, forming thus the well-known
Be^ian block and Telford pavements. Such are set in regular
rows and the interspaces filled with sand and sometimes with tar or
asphalt. For suburban and country roads a pavement of broken
stone, the invention of a Mr. L. Macadam about 1820, and known
ov Google
493 THE NON-METALUC MINERALS.
by his name, is at present the most extensively used. The invention
is based upon the property possessed by freshly broken stone of
becoming compacted and to a certain degree even cemented when
subject to heavy rolling and the impact of wheels. The finer
particles, broken away by the action of the wheels and hoofs of
animab, fill the interstices of the lai^er pieces and gradually bring
about an induration, forming a roadbed hard, smooth, and durable.
Not all materiab are equally good for macadamizing purposes.
If the rock is too hard ordinary travel is not sufficient to produce
the desired amount of fine material, and satisfactory cementation
does not ensue. If too soft it grinds away too rapidly. If the
material is decomposed, it does not become sufficiently indurated
— refuses to set, as it were.
It is impossible to lay down other than the most general rules
for the selection of road material, since rocks of the same kind, or at
least known under the same name, vary almost as much in different
localities in their physical properties as do the different kinds. The
following very general rules have been formulated: •
The granites are generally brittle, and many of them do not binci
well, but there are a great many which, when used under proper
conditions, make excellent roads. The felsites are usually very bard
and brittle, and many have excellent binding power, some varieties
being suitable for the heaviest macadam traffic. Limestones gener-
ally bind well, are soft, and frequently hydroscopic. Quartzites are
almost always very hard, brittle, and have very low binding power.
The slates are usually soft, brittle, and lack binding power.
Obviously the bulk matter of any roadbed must be built up of
materials from nearby sources, owing to cost of transportation. For
surfacing, however, materials are often carried long distances. For
this purpose a hard, dense rock, such as the finer grades of trappean
locks, are now most generally used.
Macadam is laid with or without a foundation of laiger stones.'
' L W Page. The Selection of Materials for Mac&dam Roads, Yearbook Dipt
ot Agriculture, igoo.
' With the foundation ol latter stonei the pavement becomes known ai
the Macadam-Telford pavement
ov Google
MISCELLANEOUS. 423
When such is used, a thickness of from 6 to 12 inches is recommended
and over this is laid from 4 to 6 inches of the broken stone or " metal,"
"Taking all points into consideration, it is probable that the
best size for macadam, for hard and tough stones, such as basaU,
close-grained granite, syenite, gneiss, and the hardest of primary
crystallized rocks, is from ij to ij inches cube, according to their
respective toughness and hardness, while stones of medium quality
ought to be broken to gage of from ij to 2^ inches, and the softer
kinds of stone might vary between the limits of 2 and 2\ or 2J inches,
but the latter is a size which should seldom be specified."
On roads for light driving it is customary to place a final surfacing
of smaller stone, such as will pass a i-inch mesh.
"Considerable importance is attached to the manner in which
the macadam is prepared for use. Machine-broken stone is not
considered of the same value as that broken by hand. The stones
are not so regular a size and shape, and there is a greater proportion
of inferior stuff. A mechanical crusher is apt to stun the material,
and does not leave the edges so sharp for binding as they are when
the stone is broken with a small hammer." '
The cost of macadamized roads from necessity varies almost in-
definitely. The primary factors are (1 ) cost of labor, {2) accessibility
of materials, and (3) character of country. From $3,000 to $2,500
a mile is perhaps an average figure for localities where materials are
available close at hand.
BIBLIOGRAPHY.
Reports of the Masaachiuetu Highway Commiiuaii, 1S94, and othen up
to date.
N. S. Shalzx. Geology of Road Building Stones of Mass.
Sixteentb Annual Report, U. S. Geol. Survey, 1894-95, pp. 977-341.
F. J. H. Mekkill. Road Materials and Road Building.
Bull. N. Y. State Museum, Vol. IV, No. 17, 1897.
L. W. Face. The Selection of Materials foi Macadam Roads.
Yearbook Dcpt. of Agriculture, 1900.
O. W. TiLisoN. Street Pavements and Paving Material. J. Wiley and Sons, 1901.
' CiicnUi No. la, U.S. Depattmeat of Agriculture, Office of Road Inquiry, 189&
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J, Google
Adobe, J3S-
ARalmatolite, 315, 316.
Albenite, 383.
Allanite, 304.
AllocUaite, 37.
Alum Clay, 344.
Aluminite, 355.
Ahim Slate, 357,
Alumt, Tbe, 350.
Alunite, 353.
Alimo^n, 353.
Amber, 391.
Amber Occunrences, 393.
Ambljigonhe, 309.
Anhydrite, 56.
Anthracite Coal, 364.
Apatite, 3(7.
Apatite Deports of Canada, 374.
Apatite, Occurrences of, 373.
Apjohnite, 351.
Arsenic, Bibliography of, 34,
Arsenic, Occurrence of, 33.
Arsenic, Uses of, 34.
Arsenical Pyrites, 30.
Arsenopyrile, 30,
Asbestic, 194.
Asbestos, Bibliography of, 197.
Asbestos, Composition of, 186.
Asbestos Deposits of Arizona, 191.
Asbestos Deposits of Canada, 189.
Atbestot Deports of Georgia, 1S8.
Asbestos Deposits of Maryland, 189.
Asbestos Deposits of Vermont, 191.
Asbestos Deposits of Virginia, 188.
Asbestos, Localities of, 1S9.
Atbatos Mining and Preparation of,
Asbestos, Occurrence and Origin of,
■8s.
Asbestos, Uses of, 193.
Asbestos, Varieties of, 183.
Aabolite, 98.
Asphalt, Bibliography of, 398.
Asphaltic Sandrocit, 379.
Asphaltum. 375.
Asphalt, Uses of, 3S0.
Astrakaulle, 56.
Barite, Compodtion of, 334.
Bariie, Occurrence of, 335,
Barite, Preparation and Uses, 336.
Bat Guano, 399.
Bauxite, Bibliography of, ros.
Bauxite, Composition, 89.
Bauxite, Origin anr< Occurrence, 91.
Bauidte, Uses o(, lor.
Bauxite Deposits of Alabama, 97.
Bauxite Deposits of Arkansas, 94.
Bauxite Deposits of France, 91.
Bauxite Deposits of Georgia, 97.
Bauxite Deposits of Germany, 93,
Bedded Clays, 330.
Belgian Razor Hone, 408.
Benton ile, 346.
Bieberite, 39.
Biotite, 178.
Bisciioffile, 56.
Bitumens, Bibliography of, 398.
Bitumens, Classification of, 368.
Bitumens, Origin of, 369.
Bitumens, The, 367.
Bituminous Coal, 363,
Black Diamond, 3.
Bog Manganese, 134.
Boracite, 56, 333.
4'S
ov Google
436
Borate <rf Soda (see Boiux), 311.
Borate of Magnesia, 31a.
Borates, Occurrences and Localities,
3". 3".
Boronatrocalcite, 331.
Bort, 3.
Braunite, iii, 112.
Brickclays, 133.
Brown Coal, 363.
Buhrslone, 68.
Calcite, 135.
Calcium Carbonate, 135.
Calc Spar, 135.
Calc Spai, Origin and Occurrence oF,
Carbon, i.
Carbonado, 3.
Carbonates, 135.
Carbonile, 385.
Camalliie, $6.
Camolite, CompoMtion ot, 333, 333.
Camotlie, Occurrence of, 33»,
Camotilc, Uses of, 334.
CeksUte, Composition and Occurrence,
343-
Cclestiie, Uses, 344-
Cement, Bibliography of, t6o.
Cement, Hydraulic, 140.
Cemenl, Portland, 141.
Cement, Roman, 144.
Cement, Rosendale, 143.
Cerite, 307.
Chalk, Composition and Uses, 146.
Chalk, Origin and Occurrence, 145.
Chemawinite, 3^3.
Chilian Nitrate, Composition and
Occurrence, 317.
China Clay, 137.
Chromite, 114.
Chromite, Bibliography of, 130,
Chromite, Composition of, 115.
Chromite Deposits of California, 117.
Chromite Deposits of Canada, 116.
Chromite Deposits of Greece, lao-
Chromite Deposits of Maryland, 1 19.
Chromite Deposits of NewfeunciJaiid,
118.
Chromite Depodls of Nortb Caroliiu,
116.
Chromite DepoMts of S, Africa, 117.
Chromite, Domestic Source of, 117.
Chromite, Occurreiures and Origia,
116.
Chromite, Uses of, iiB.
Clays, Bibliography oE, 150.
Clays, Cause of Plasticity, 338.
Clays, Composition of, 318, aag, aji,
133-337. »4S-=49-
Clays, Kinds and Clas^&cation, 336.
Clays, Mineral and Chemical Composi'
tion, 334.
Clays, Origin and Occurrence, 221.
Clays, Properties of, 336.
Clays, Testing of, 340.
Claya, Uses, 241.
Coals, Bibliography of, 366.
Coals, The, 359.
Cobalt, Bibliography of, 30.
Cobalt Bloom, 18.
Cobaltite, 25.
Cobalt Minerals, 25.
Coballomenitc, 39.
Cobalt, Uses of, 30.
Colcothar, 37,
Colemanite, 333.
Columbite and Tantalite, 355.
Columbiie, Compositbn, Occurmtce
and Uses, 355.
Copal. 394-
Copperas, 37.
Corundum, 33.
Corundum Deposits of Canada, 79.
Corundum Deposits of Georgia, 77.
Corundum Deposits of Montana, 78.
Corundum Deposits of North Cuolina,
74.
Corundum, Occurrence of, 74.
Corundum, Origin of, 80.
Crocus, 104.
Cryolhc, Composition and Occurtence
of, 65.
1 Got>^lc
Cryolite, Uses of, 66.
Descloizite, 31a.
Diallogiie, 159.
DiamoiHl, I.
Diamond, Bibliography of, 5.
Diamond, Origin and Occurrence of, 1.
Diamond, Uses of, 5.
Diaspore, 103,
Diatom Earth, Composition of, 73.
Diatom Earth, Occurrence and Origin,
70.
Dialom Eanh, Uses of, 71.
Dolomite, Compositioo and Uses, i$2.
Douglasiie, 56.
Elateriie, 38a.
Elements, The, 1.
Emery, Bibliography of, 88, 89.
Emery, Composition of, 81.
Emery Depodls of Asia Minor, Ss.
Emery Depoats oC Massachusetts, 84.
Emery Deposits of Naxos, 81, 83.
Emery Deposits of New York, 86.
Emery Deposits of the United States, 84.
&nery, Sources and Uses, 87.
Emery, Turkish, 83.
Epsomlte, Epsom Salts, 348.
Erythrite, a8.
Feldspars, Compoatbn of, t6i.
Feldspats, Occuiience of, 161.
Feldspars, Uses of, 164.
Feldspars, Weathering of, i6t.
Ferberite, 257, 160.
Fire Clay, 130, 341.
Flint, 68.
Fluorite, Bibliography, 65.
Fluorite, Occurrence, 63.
Fluoriie, Uses, 65.
Franklinite, an, 133.
Fullers Earth, 351.
FullersEarlh, Composition of, 154.
Fullers Earth, Localities of, 952.
Fullers Earth, Uses of, 154,
Gadolinhe, 305.
Garnets, Occurrence of, 19B.
Garnet, Uses of, 199.
V. 42;
Gibbsite, 103.
Gilsonite, 386.
Glass Sand, 419.
Glauberilc, 56, 347.
Glauber Sail, 344,
Glaucodot, 37.
Glauconitic Sand, 430.
Orahamite, 3S4.
Graphite, 6.
Graphite, Bibliography of, 13.
Graphite, Canadian, it.
Graphite, E^l Indian, 11.
Graphite in the United States, 11.
Graphite Moravian, to.
Graphite, Mexican, to.
Graphite, Occurrence and Origin of, 6.
Graphite, Preparation of, 11.
Graphite, Price of, 13.
Graphite, Sources of, II.
Graphite, Uses of , 13.
Graphite, World's Production of, 13,
Grindstone, Materials for. 400.
Guanos, Compontion of, 395, 199.
Guanos, Origin of, 373.
Guanos, Soluble and Leached, 394.
Gum Copal, 394.
Gypsum, Age and Mode of Occurrence,
338.
Gypsum, Composition, 337.
Gypsum, Origin of, 338.
Gypsum, Uses of, 343.
Halides, The, 43.
Halite, Composition, 43, 44.
Halite, Mining and Manufacture of, 56.
Halite, Origin and Occurretu:e, 44.
Halite, Uses of, 61.
Halotrichite, 351.
Halotrichite, Composition of, 353.
Ha Hoy site, 318.
Hausmanite, 121, 113.
Heavy Spar, 334,
Holystone, 409.
Hones, Materials for, 400.
Hubnerite. 357, 363.
Hydraigillite, 103.
Hydraulic Limes and Cements, t6a.
Hydrocarbon Compound, 3;9.
Hydraulic Cement, 140.
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Iceland Spar, OHg^ and Occurrence,
IfancDite, 113.
Indianaite, 130.
Indian Red, 104.
Infusorial Earth (aee Diatom Eaith), 70.
Iron Pythes, 32.
Ifland of Trinidad, Aqihalt of, 375.
Jrt. 36a.
Ktunile, 56.
Kalinite, 350.
Kaolins derived from Feldspars, tsi.
Kerosene Shale, 363.
Kieserite, 56.
Kimberlile, l.
Kimberly Diamond Mines, 3.
Knigile, 56,
Lapis-I&zuli, xi.
Lapis-lazuli, LocaUttea and Occurrence,
106.
Lapis-lazuli, Uses of, 303.
Lazarite, Compoiition and Occunence,
Leda Clays, 133.
Lepidolite, 178.
Lepidolite, Occurrence and Origin, 319.
Lepidolite, Uses of, asa.
Leucopyrlte, Occurrence and Uses, 31.
Lignite, 363.
Limes and Cements, Bibliography of,
160.
Umes, Classification of, 141.
Limestones, Kinds and Origin, 138.
Ijmestone, Lithi^aphk, 147.
Limestone, Uses of, 139,
Linncite, 37.
Lithogn^hic Limestone, 147.
Lithographic Limestone, Composition
of. 148.
Utbogrvphic Limestone, Localities of,
147-
LillM^hi;iite, 310,
Lollingile, Occurrence and Uses, 31.
Loess, 136.
Macadam, Material for, 493.
Madstones, 413.
Magnesile, Composittoo of, 153.
Magnesite, L.ocalities of, 154.
Magneate, Origin and Occurreiioe, 154.
Magne^te, Price of, 156.
Magnesile, Uses of, 156.
Magnetic Pyrites, 38.
Manganese Deposits of Braiil, iij.
Manganese Deports of Cuba, 117.
Manganese Deposits of New Bruns-
wick, 1 17.
Manganese Depouts of Virginia, 1 35.
Manganese Oxides, Compositioi) ut,
Maogancse Oxides, Occurrence of, 135.
Manganese Oxides, Origin of, 134.
Manganese Oxides, Uses of, 119.
Manganite, ui. 133.
Manganosite, I3r.
Manjak, 387.
Marbles, Playing, 146.
Marcasile, 33.
Marsh Gas, 371.
Meerschaum (see Sepiolite), 118.
Menace anite, lit.
Mendozite, 351.
Mica, Bibliography of, 183.
Mica, Composition of, 165.
Mica Deports of Alabama, 173.
Mica Deposits of Canada, 175.
Mica Deposits of Colorado, 173.
Mica Deposits of Connecticut, 169.
Mica Deports of Maine, 168.
Mica Deports of Nevada, 174.
Mica Deposits of New Hampshire, 16S.
Mica Deposits of New Mexico, 173.
Mica Deports of North Carolina, 169.
Mica Deposits of South Dakota, 173,
Mica Depoeits of Wyoming, 173.
Mica, Localities of, 167.
Mica, Occurrence of. 166.
Mica, Origin of, 167,
Mica, The, 164.
Mica, Uses of, 180.
Millstones, 409.
Mineral Caoutchouc, 381.
Mineral Paint, Composition of, 105.
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Mineral Phosphates, Localities, 173.
Mineral Pitch, 375.
Mineral Water, Classification, 131, iji.
Mineral Water, Distribu(bn, ijj.
Mineral Water, Production of, 134,
Mineral Water, Source of, 133.
Mineral Water, Uses of, 133.
Mineral Wax, 388.
Mirabilite, Composition, 345, 346.
Mirabitite, Occurrence, 344.
Mispicltel, 30.
Molding Sand, 413.
Molding Sand, Bibliography of, 41S.
Molding Sand, Composition of, 4r4,
415-
Molding Sand, Localities of, 417.
Molding Sand, Mechanical Analysis of.
Molybdenite, 39.
Molybdenite, Occurrence of, 40.
Molybdenite, Uses of, 4(,
Monazite, 303.
Monazite, Bibliography of, 30S.
Monazile, Composition of, 304.
Monazitc, Localities and Occurrences,
Monaiite, Methods of Ertraclbn, 306.
Monazite, Occurrences of, 304.
Monazite, Uses oC, 307.
Muscovite, 168.
Natron, 159,
Natural Coke, 385.
Natural Gas, 37a.
Niobaies, Tantalates and Tungstates,
'Si-
Niter, 3t5,
Nitrates, Bibliography of, 311.
Nitrates, Composiikin of, 317.
Nitrates, Origin of, 319,
Nitrates, Uses, 331.
Nitrates, The, 315.
Nitro-Calcite, 31 8.
Nitrous Earth, Composition of, 319,
Novaculite, 406, 407.
Ochen, Artificial, Production of, 104.
X. 429
Ochers, Bibliography of, 112.
Ocbers, Composition of, 104, 105,
Ocher, Origin and Mode of Occurrence,
Other, Preparation of, 109.
Ocher, Uses, ni.
Orpimeni, Occurrence, *3.
Ortbite, 204,
Oxides, The, 67,
Ozokerite, 388.
Ozokerite, Uses of, 391.
Paint, Mineral, 103.
Paper Clay, 243.
Paraffin, Native, 388,
Patronite, 4r.
Patronite, Bibliography of, 43.
Patronite, Occunence of, 43.
Patronite, Origin of, 43.
Patronite, Uses of, 43.
Peat, Origin and Composition, 360.
Petalile, mo, Mr.
Petroleum, Bibliography of, 398.
Petroleum, Composition of, 373.
Petroleum, Uses of, 374.
Phlogopite, 175.
Phosphate and Vanadates, 266.
Phosphates, Bibliography of, 301.
Phosphates, Composition of, 168, 171,
375-377, 394, 396-398.
Phosphate Deposits of Arkansas, 386.
Phosphate Deports of Belgium, 391.
Phosphate Deports of Canada, 373.
Phosphate Deposits of England, sSS.
Phosphate Deposits of Florida, 380.
Phosphate Deposits or France, 390.
Phosphate Deposits of Germany, 191. '
Phosphate Deposits of Idaho. 38S.
Phosphate Deposits of Italy, 39a.
Phosphate Deposits of Maltese Islands,
393-
Phosphate Deposits of Navassa, 396.
Phosphate Deposits of Nevada, 187.
Phosphate Deposits of North Carolina,
278.
Phosphate Deports of Norway, 175.
Pbospbate Deposits of Portugal, 3771
Phosphate Depotits of Redonda, 39S,
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phosphate Deposits of Russia, 19a.
Phosphate Deposits of Sombrero, 396.
Phoq>hale Deposits of South Carolina,
180.
Pbo^hale Deposits of Spun, 176.
Phosphate Deposits of Tennessee, >8i.
Phosphate Deposits of Tunis, igi.
Phosphate Deports of United Slates,
188.
Phosphate Deports of West Indies,
296.
Phosphate Deposits of Wyoming, 188.
Phosphates, Nodular, 371.
Phosphates, Uses of, 300,
Phosphorite, 969.
Phosphorite, Oicuirence of, 176.
Pickeringile, 351.
Finite, 216.
Pipe Clay, 230.
Pitchblende (see Uraninite), 330.
Plaster of Pads, 343.
playing Marbles, 146.
Plumbago, 6.
Polianite, 121, 113.
Polyhalite, 56.
Portland Cement, 141.
Potassium Nitrale, 315.
Potter's Clay, 330, 143.
P»lomelane, 121, 113,
Pumice, 410.
Pumice dust, 411.
Pyrallolile, 208,
Pyrfle, 32.
Pyrite, Bibliography of, 39.
Pyrite, Composition of, 33.
Pyrite Deposits of New York, 34.
Pyrite Deposits of Spain, 35.
lyite Deposits of Virginia, 34.
Pyrite, Occurrence and Origin, 33,
Pyrite, Uses of, 36.
Pyrolusile, 121, 133.
Pyrophyllite, a 16.
Pyrophyllite, Occurrence and Uses,
217.
Pynhotite, 38,
Quartz, Varieties and Uses, 67.
Quicklime, 140.
Rare Earths, Bibltc^raphy of, 30S.
Rare Earths, Uses of, 307.
Razor Hones, 408.
Realgar, Occurrences, 23.
Reichardite, 56.
Remingtonite, 29.
Rensselaerite, 108.
Resin, 391.
Resins, Bibliography of, 39S.
Retinite, 393,
Rhodochrosite, 159.
Rhodonite, 207.
Road-making Materials, 4JI.
Road Materials, Bibliography of, 433.
Rock Phosphate, 26S, 27S.
Rock Phosphate, Origin and OccurreDcc^
26S.
Rock Salt, 43.
Rocic Soap, 244.
Roman Cement, 144.
Roscoeliie, 179.
Rosetite, 38.
Rottenstone, 412.
Rouge, 104.
Rulile. Bibliography of, 114.
Rulile, Ix>calities of, 113.
Rulile, Mode of Occurrence, 113.
Saffln
Salt, Common (s
Salt Depo!
Salt Deposits of
Salt Deposits of
Salt Deports of
Salt Deposits of
Salt Deposits of
Sail Deposits of
Salt Deposits of
Sah Depo!
Salt Deposits of
Salt Deposits of
Salt Deposits of
Salt Depo!
Salt Deposits of
Salt Deposits of
Salt Deposits of
Salt Deposits of
Salt Deposits of
(see Halite), 43.
" California, 58.
Canada, 47.
Colorado Desert, 57.
England, 53.
Germany, 54.
Great Salt Lake, 59.
Kentucky, 51,
U,ul.im 50.
New York, 47,
Ohio, 49.
Ontario, 47.
Petite Ansc,50,57.
Poland, 54.
Stassfurth, 54.
r,x^ 5..
Wielicka, 54, 62.
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Salt DepOMts of Virginia, 46-
Samai-^ite, 156.
Sand for Glass Making, 419.
Sand for Mortars and Cements, 41S.
Schoelite, Occurrence and Usee, 163.
SchtSnite, 56.
Scotch Hones, 405.
Segers- Cones, 141.
Sepiolite, Composition of, aiS.
Siegenite, I^.
Silica, 67.
Silicates, Tlie, 161.
Skutterudile, 17. '
Slip Clays, 334.
Smaltite, 16.
Soapstone, aoS.
Soapstone, Composition of, 109.
Soapstone Deposits of Maryland, atj.
Soapstone Deposits of Massaciiiisetls,
Soapstone Deposits of New Hampshire,
Soapstone Deposits of North Carolina,
314.
Soapstone Deposits of Pennsylvania,
Soapstone Deposits of Vermont, zii.
Soapstone Deposits of Virginia, aij.
Soapstone Industry of China, 115.
Soapstone, Localities, 211.
Soapstone, Occurrence, 111.
Soapstone, Uses, 314.
Soda Lakes, 346.
Soda Niter, 315.
Sodium Nitrate, Localities of, 315.
Sphnocobaltite, 3S.
Spodumene, Composilbn and Occur-
Spodumene, Uses of, aoi.
Stas^uTtite, 331.
Steatite, 3oS.
Stionlianile, Occurrence and Uses, 158.
Succinite, 391.
Sulphates, 334,
Sulphate of Iron, from Pyrite, 37.
Sn^htir, 14.
Sulphur, BibKography of, 33.
Sulphur Deposits of Japan, 30,
431
Sulphur Deposits of Louisiana, 16.
Sulphur Deposits of Nevada, 17.
Sulphtu' Deposits of Sicily, 19.
Sulphur Deposits of Texas, 19.
Sulphur Deposits of Utah, 19.
Sulphur, Ertiaction and Preparation of.
Sulphur, Localities of, 15.
Sulphur, Occurrence and Origin, 14.
Sulphur, Uses of, 31.
Syncbnodymite, 38.
Tachydrite, 56.
Talc, 308.
Talc, Occurrence and Origb, 309.
Talc and Steatite, Composition of, 309.
Talc Deposits of New York, aio.
Talc Deposits of North Carolina, ati.
Talc Deposits of Viiginia, 310.
Talc, Uses, 314.
Terra Alba, 343-
Thenardite, 348.
Tincal, 333.
Titanic Iron, 113,
Torbemite, 307.
Triphyllile,3io.
Tripoli, 69.
Trona, [59.
Tschermigite, 350.
Tungstaies, Bibliography of, 165.
Turkey Oilstone, 408.
Uintaite, 386.
Ulexile, 333.
Ultramarine, 30a.
Uranates, 330.
Uraninite, 330.
Uraninite, Localities and Occuiience,
330-
Uraninite, Uses, 331.
Vanadates, Uses of, 314.
Vanadinite, 311.
Vanadium Mica (see Roscoelite), 179.
Vanadium Sulphide (see Patroniie), 41,
Vitriol Stone, Composition of, 37.
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Wad, 131, 114.
Water, Mmeral, 131.
Water of Ayr Stone, 405.
Wave] lite, 308.
Welsbach Light, 308.
Whetstones, Materials for, 40a.
Witherite, Localities, Occurrences and
Uses, 157.
Wolframite, Bibliography of, 365.
WoUramite, ConpositkHi of, 357.
Wolframite, Hubnerite and Ferberhe,
its?'
Wolframite, Occurrence of, a; 7.
Wolframite, Uses of, 364,
Wtutiillite, 383.
Vttrotantalile, 155.
Srccn, 199.
^rcon, Uses of, 39S.
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