LIBRARY
OF
A. KOFOID.
b&c-L U.b.
THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID
ERKELEY
I2R-\RY
NIVERSITY OF
CALIFORNIA
EARTH
CIENCES
JBRARY
MANUAL
OP
MINEIjALOGY JIND LITHOLOGT,
CONTAINING
Tne Elements of tie Science of Minerals and Rods.
FOR THE USE OF
THE PRACTICAL MINERALOGIST AND GEOLOGIST, AND FOR INSTRUCTION
IN SCHOOLS AND COLLEGES.
BY JAMES D. DANA.
THIRD EDITION.
RE-ARRANUKD AND RE-WHITTEN.
FOURTEENTH THOUSAND.
ILLUSTRATED BY NUMEROUS WOOD-CUTS.
NEW YORK :
JOHN WILEY & SONS.
1886.
COPYRIGHT,
1878,
BY JOHN WILEY & SONS.
EARTH
SCIENCES
LIBRARY
PEE FACE.
THIS Manual in its present shape is new throughout. In the reno-
vation it has undergone, new illustrations have been introduced, an'im-
proved arrangement of the species has been adopted, the table for the
determination of minerals has been reconstructed, and the chapter on
rocks has been expanded to a length and fullness that renders it a
prominent part of the work. But while modified greatly in all its
parts, it is still simple in its methods of presenting the facts in crys-
tallography, and in all other explanations ; and special prominence is
given, as in former editions, to the more common minerals, with only
a brief mention of others. The old practical feature is retained of
placing the ores under the prominent metal they contain, and of giving
in connection some information as to mines and mining industry.
The student is referred to the Text-book of Mineralogy, prepared
mainly by Mr. E. S. DANA, for a detailed exposition of the subject of
crystallography after Naumann's and Miller's systems, and also of
optical mineralogy and other piiysical branches of the science; to
the Manual of Determinative Mineralogy and Blowpipe Analysis by
Professor GEORGE J. BRUSH, for a thorough work on the use of the
blowpipe, and complete tables for the determination of minerals;
and to the author's Descriptive Mineralogy and its Appendixes for a
comprehensive treatise on all known minerals.
JAMES D. DANA.
NEW HAVEN, Nov. 1, 1878..
1923:
TABLE OF CONTEXTS.
MINERALOGY.
MINERALS : General Remarks I
I. CRYSTALLIZATION OF MINERALS: CRYSTALLOGRAPHY.
1. General Remarks on Crystallization 4
2. Descriptions of Crystals 8
Explanation of Terms 8
Measurement of Angles ; Goniometers 9
I. SYSTEMS o; \LLIZATIOX: Forms and Struc-
ture of Crystals 14
1. Isometric System 1?
2. Dimetric or Tetragonal System 30
3. Trimetric or Orthorhombic System 37
4. Monoclinic System 40
5. Triclinic System 43
6. Hexagonal System 45
1. Hexagonal Section 46
2. Rhombohedral Section 49
7. Distinguishing Characters of the Systems 54
II. TWIN OR COMPOUND CRYSTALS 55
III. CRYSTALLINE AGGREGATES 58
II. PHYSICAL PROPERTIES OF MINERALS.
1. Hardness 63
2. Tenacity 64
3. Specific Gravity 64
4. Refraction and Polarization 66
5. Diaphaneity, Lustre, Color TO
6. Electricity and Magnetism 73
7. Taste, Odor 74
V
yj TABLE OF CONTENTS.
III. CHEMICAL PROPERTIES OF MINERALS.
PAGE
1. Chemical Composition 76
2. Chemical Reactions 81
1. Trials in the Wet Way 81
2. Trials with the Blowpipe 83
IV. DESCRIPTIONS OF MINERALS.
• 1. Classification 91
2. General Remarks on Ores 92
I. MINERALS CONSISTING OF THE ACIDIC ELEMENTS.
1. Sulphur Group 94
2. Boron Group 97
8. Arsenic Group 98
4. Carbon Group 102
II. MINERALS CONSISTING OF THE BASIC ELEMENTS WITH
OR WITHOUT ACIDIC — THE SILICATES EXCLUDED.
Gold 109
Silver and its Compounds 116
Platinum, Iridium, Ruthenium 124
Palladium 127
Mercury and its Compounds 128
Copper and its Compounds 130
Lead and its Compounds. ., 145
Zinc and its Compounds 154
Cadmium, Tin 159
Compounds of Titanium 162
Cobalt and Nickel and their Compounds 163
Uranium and its Compounds 169
Iron and its Compounds 171
Manganese and its Compounds 188
Compounds of Aluminum 192
Compounds of Cerium, Yttrium, Erbium, Lanthanum and
Didymium 201
Compounds of Magnesium 204
Compounds of Calcium 207
Compounds of Barium and Strontium 220
Compounds of Potassium and Sodium 223
Compounds of Ammonium 230
Compounds of Hydrogen , 231
TABLE OF CONTENTS. yij
III. SILICA AND SILICATES.
1. SILICA. TAGE
Quartz 233
Opal ; 239
2. SILICATES.
General Remarks 242
1. Anhydrous Silicates.
1. Bisilicates 243
Pyroxene and Amphibole Group. 244
Beryl, etc ! 252
2. Unisilicates 254
Chrysolite Group 255
Garnet Group 256
Zircon Group 259
Idocrase, Epidote, etc 261
Axinite, lolite , ... 264
Mica Group 265
Scapolite Group 268
Nephelite, Sodalite, Leucite 269
Feldspar Group 272
3. Subsilicates 280
Chondrodite, Tourmaline -. 281
Andalusite, Fibrolite, Cyanite 284
Topaz, Euclase 288
Datolite, Sphene, Staurolite , . . 289
2. Hydrous Silicates.
1. General Section 292
Pectolite, Laumontite, Apophyllite 293
Prelinite, Allophane 295
2. Zeolite Section , 297
Thomsonite, "Natrolite, Analcite, Cliabazite 298
Harmotome, Stilbite, Heulandite 301
3. Margarophyllite Section 804
Talc, Pyrophyllite, Sepiolite SOI
Serpentine, Deweylitc, Saponite 307
Kaolinite, Finite 310
Hydromica Group 312
Fanlunite, Hisingerite 315
Chlorite Group 316
yiH TABLE OF CONTENTS.
IV. HYDROCARBON COMPOUNDS.
PACK
1. Simple Hydrocarbons 321
2. Oxygenated Hydrocarbons 325
3. Asphaltum and Mineral Coals 328
SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
1. Catalogue of American Localities of Minerals 333
2. Brief Notice of Foreign Mining Regions 375
IY. DETERMINATION OF MINERALS.
General Remarks 379
Table for the Determination of Minerals. . . 384
ON BOCKS.
1. Constituents of Rocks 409
2. Classes of Rocks 413
3. On some Characteristics of Rocks 414
Use of the Microscope in the Study of Rocks 422
4. Kinds of Rocks 424
1. Fragmental Rocks, exclusive of Limestones 426
2. Limestones or Calcareous Rocks 430
3. Crystalline Rocks, exclusive of Limestones 434
1. Siliceous Rocks 435
2. Mica and Potash-Feldspar Series 437
-8. Mica and Soda-lime Feldspar Series 443
4. Hornblende and Potash-Feldspar Series 444
5. Hornblende and Soda-lime Feldspar Series 446
C. Pyroxene and Soda-lime Feldspar Series 450
7. Pyroxene, Garnet, Epidote, and Chrysolite Rocks,
containing little or no Feldspar 452
8. Hydrous Magnesian and Aluminous Recks 453
9. Iron-ore Rocks ... . 455
MINERALOGY.
MINERALS,
MINERALS are the materials of which the earth consists, and
plants and animals the living beings over the surface of the
mineral-made globe. A few rocks, like limestone and quartz-
yte, consist of a single mineral in more or less pure state ; but
the most of them are mixtures of two or more minerals.
Through rocks of each kind various other minerals are often
distributed, either in a scattered way, or in veins and cavities.
Gems are the minerals of jewelry; and ores, those that are im-
portant for the metal they contain. Water is a mineral, but
generally in an impure state from the presence of other miner-
als in solution. The atmosphere, and all gaseous materials set
free in volcanic and other regions, are mineral in nature,
although, because of their invisibility, seldom to be found
among the specimens of mineral cabinets. Even fossils are
mineral in composition. This is true of coal which has come
from buried plant-beds, and amber from the buried resin of
ancient trees, as well as of fossil shells and corals.
It is sometimes said that minerals belong to the mineral
kingdom, as plants to the vegetable kingdom, and animals to
the animal kingdom. Substituting the term inorganic for min-
eral, the statement is right ; for, as there are the two kingdoms
of life, so there is in Nature what may be called a kingdom, or
grand division, including all species not made through the
organizing principle of life. But this inorganic kingdom is not
restricted to minerals ; it embraces all species made by inor-
ganic forces — those of the earth's crust or surface, and, also,
whatever may form under the manipulations of the chemist.
The laws of composition and structure, exemplified in the consti-
tution of rocks, are those also of the laboratory. A species mada
2 CHAEACTEES OI MINEEALS.
by art, as we term it, is not a product of art, but a result solely
of the fundamental laws of composition which are at the basis
of all material existence; and the chemist only supplies the
favorable conditions for the action of those laws. Mineral
species, are then, but a very small part of those which make up
the inorganic kingdom or division of Nature.
CHARACTERS OF MINERALS.
1. Minerals, unlike most rocks, have a definite chemical
composition. This composition, as determined by chemical
analysis, serves to define and distinguish the species, and indi-
cates their profoundest relations. Owing to difference in com-
position, minerals exhibit great differences when heated, and
when subjected to various chemical reagents, and these peculi-
arities are a means of determining the kind of mineral under
examination in any case. The department of the science treat-
ing of the composition of minerals and their chemical reactions
is termed CHEMICAL MINERALOGY.
2. Each mineral, with few exceptions, has its definite form,
by which, when in good specimens, it may be known, and as
truly so as a dog or cat. These forms are cubes, prisms, double
pyramids, and the like. They are included under plane sur-
faces arranged in symmetrical order, according to mathematical
law. These forms, in the mineral kingdom, are called crystals.
Besides form there is also, as in living individuals, a distinctive
internal structure for each species. The facts of this branch of
the science come under the head of CRYSTALLOGRAPHIC MINER-
ALOGY.
3. Minerals differ in hardness — from the diamond at one end
of the scale to soapstone at the other. There is a still lower
limit in liquids and gases ; but of the hardness or cohesion in this
part of the series the mineralogist has little occasion to take
note.
Minerals differ in specific gravity, and this character, like
hardness, is a most important means of distinguishing species.
Minerals differ in color ', transparency, lustre, and other opti-
cal characters.
A few minerals have taste and odor, and when so these char-
acters are noticed in descriptions.
The facts and principles relating to the above character!
are embraced in the department of PHYSICAL MINERALOQ r.
In addition to the above-mentioned branches of the science
CHARACTERS OF MINERALS. 3
of minerals there is also (4) that of DESCRIPTIVE MINERALOGY,
under which are included descriptions of the mineral species ;
and (5) that of DETERMINATIVE MINERALOGY, which gives a
systematic review of the methods for determining or distinguish-
ing minerals.
These different branches of ihe subject are here taken up in
the following order • I. Crystallographic Mineralogy ; £1. Phys-
ical Mineralogy; III. Chemical Mineralogy; IV. Descriptive
Mineralogy ; V. Determinative Mineralogy. On account of
the brief manner in which the subjects are treated in this
volume, the heads used for the several parts are, (1) The Crys-
tallization of Minerals • (2) Physical Properties of Minerals /
(3) CJiemical Properties of ^Minerals ; (4) Descriptions o
ties / (5) Determination of Minerals.
4
CRYSTALLOGRAPHY.
1. CRYSTALLIZATION OF MINERALS:
CRYSTALLOGRAPHY.
1. GENERAL REMARKS ON CRYSTALLIZATION.
THE attraction which produces crystals is one of the funda-
mental properties of matter. It is identical with the cohesion
of ordinary solidification ; for there are few cases outside of the
kingdoms of life in which solidification takes place without some
degree of crystallization. Cohesive attraction is, in fact, the
organizing or structure-making principle in inorganic nature, it
producing specific forms for each species of matter, as life does
for each living species. A bar of cast-iron is rough and hackly
in surface, because of the angular crystalline grains which the
iron assumed as solidification took place. A fragment of mar-
ble glistens in the sun, owing to the reflection of light from in-
numerable crystalline surfaces, every grain in the mass having
its crystalline structure. When the cold of winter settles over
+he earth in the higher temperate and colder latitudes it is the
CRYSTALS OP SNOW.
•ignal for crystallization over all out-door nature; the air «
filled with crystal flakes when it snows ; the streams become
coated with an aggregation of crystals called ice; and windows
are covered with frost because crystal has been added to crystal
CEYSTALLOGEAPHY.
5
in long feathered lines over the glass — Jack Frost's work being
the making of crystals. Water cannot solidify without crystal-
lizing, and neither can iron nor lead, nor any mineral material,
with perhaps half a dozen exceptions. Crystallization produces
masses made of crystalline grains when it cannot make distinct
crystals. Granite mountains are mountains of crystals, each
particle being crystalline in nature and structure. The lava
current, as it cools, becomes a mass of crystalline grains. In
fact the earth may be said to have crystal foundations ; and if
there is not the beauty of external form, there is everywhere
the interior, profounder beauty of universal law: — the same law
of symmetry which, when external circumstances permit, leads
to the perfect crystal with regular facets and angles.
Crystals are alone in making known the fact that this law
of symmetry is one of the laws of cohesive attraction, and that
under it this attraction not only brings the particles of matter
into forms of mathematical symmetry, but often develops scores
of brilliant facets over their surface with mathematical exact-
ness of angle, and the simplest of numerical relations in their
positions. Crystals teach also the more wonderful fact that
the same species of matter may receive, under the action of this
attraction, through some yet incomprehensible changes in its
condition, a great diversity of forms — from the solid of half a
dozen planes to one of scores. The following figures represent a
few of the forms in a common species, pyrite, a compound of
iron and sulphur.
CRYSTALLOGRAPHY.
9.
12.
15.
Many more figures might be given for this one species, py-
lite. The various forms or planes in any such case have, it is
true, mutually dependent relations — a fact often expressed by
Baying that they have a common fundamental form. But it is
none the less a remarkable fact, giving profound interest to the
Bubject, that the attraction, while having this degree of unicy
in any species, still, under each, admits of the multitudinous
variations needed to produce so diverse results.
At the time of crystallization the material is usually in a
CRYSTALLOGRAPHY. 7
state of fusion, or of gas or vapor, or of solution. In the case
of iron the crystallization takes place from a state of fusion, and
while the result is ordinarily only a mass of crystalline grains^
distinct crystals are sometimes formed in any cavities. If in
the cooling of a crucible of melted lead, bismuth, or sulphur, the
crust be broken soon after it forms, and the liquid part within be
turned out, crystals will be found covering the interior. Here,
also, is crystallization from a state of fusion. When frost or
snow-flakes form it exemplifies crystallization from a state of
vapor. If a saturated solution of alum, made with hot water,
be left to cool, crystals of alum after awhile will appear, and
will become of large size if there is enough of the solution. A
solution of common salt, or of sugar, affords crystals in the
same way. Again, whenever a mineral is produced through
the change or decomposition of another, and at the same time
assumes the solid state, it takes at once a crystalline structure,
if it does not also develop crystals.
Further, the crystalline texture of a solid mass may often be
changed without fusion : e. g., in tempering steel the bar is
changed from coarse-grained steel to fine-grained by heating
and then cooling it suddenly in cold water, and vice versa, and
this is a change in every grain throughout the bar.
Thus the various processes of solidification are processes of
crystallization, and the most universal of all facts about miner-
als is that they are crystalline in texture. A few exceptions
have been alluded to, and one example of these is the mineral
opal, in which even the microscope detects no evidence of a
crystalline condition, except sometimes in minute portions sup-
posed not to be opal. But if we exclude coals and resiris this
mineral stands almost alone. Such facts, therefore, do not
affect the conclusion that a knowledge of crystallography is of
the highest importance to the mineralogist. It is important
because —
1. A study of the crystalline forms and structure of minerals
is a convenient means of distinguishing species — the crystals
of a species being essentially constant in structure and ia
angles.
2. The most important optical characters depend on the
crystallization, and have to be learned from crystals.
3. The profoundest chemical relations of minerals are often
exhibited in the relations of their crystalline forms.
4. Crystallization opens to us nature at her foundation work
*nd illustrates its mathematical character.
CRYSTALLOGRAPHY.
2. DESCRIPTIONS OP CRYSTALS.
In describing crystals there are two subjects for consider*
tion : First, FORM ; and secondly, STRUCTURE.
A. FORM, — Under form, come up for description, not only
the general forms of crystals, but also —
(1.) The systems of crystallization, that is, the relations ol
all crystalline forms, and their classification.
(2.) The mutual relations of the planes of a crystal as ascer-
tained through their positions and the angles between them.
(3.) The distortions of crystals. The perfection of symmetry
exhibited in the figures of crystals, in which all similar planes
are represented as having the same size and form, is seldom
found in nature, and the true form is often greatly disguised by
this means. The facts on this point, and the methods of avoid-
ing wrong conclusions need to be understood, and these are
given beyond. With all such imperfections the angles of crys-
tals remain essentially constant. There are irregularities also
from other sources.
(4.) Twin or compound crystals. With some species twins
are more common than regular crystals.
(5.) Crystalline aggregates, or combinations of imperfect
crystals, or of crystalline grains.
Explanations of Terms.
The following are explanations of a few terms used in connection
with this subject :
1. OctaJiedron. — A solid bounded by eight equal triangles. They are
equal equilateral triangles in the regular octahedron (Fig. 2, p. 17) ;
equal isosceles triangles in the square octahedron (Fig. 17, p. 32) ; equal
inequilateral triangles in the rhombic octahedron (Fig. 8, p. 37).
2. Double six-sided pyramids. Double eight-sided pyramids. Double
twelve-sided pyramids. — Solids made of two equal equilateral six-sided,
or eight-sided, or twelve-sided, pyramids placed base to base (Fig. 20,
p. 32, and 6, 10, pp. 46, 47).
3. Right prisms. Oblique prisms. — Eight prisms are those that are
erect, all their sides being at right angles to the base. When inclined,
they are called oblique prisms.
4. Interfacial angle. — Angle of inclination between two faces or planes.
5. Similar planes. Similar angles. — The lateral faces of a square
Srism (Fig. 2, p. 14) are equal and have like relations to the axes, and
ence they are said to be similar. Solid angles are similar when the
plane angles are equal each for each, and the enclosing planes are sev-
erally similar in their relations to the axes.
6. Truncated. Bevelled. — An edge of a crystal is said to be truncated
when it is replaced by a plane equally inclined to the enclosing planes,
as in Fig. 13, p. 19 ; and it is bevelled when replaced by two planea
CRYSTALLOGRAPHY. 9
equally inclined severally to the adjoining faces. Only edges that are
formed by the meeting- of two similar planes can be truncated or bev-
elled. The angle between the truncating plane and the plane adjoining
it on either side always equals 90 ' plus half the interfacial angle ovei
the truncated edge. When a rectangular edge, or one of 90°, is trun-
cated, this angle is accordingly 135° ( = 90°-v45°) ; when an edge of 70°.
it is 125° (=90° + 35°) ; when an edge of 140°, it is 160° (=90° 4- 70°).
7. Zme. — A zone of planes includes a series of planes having the
edges between them, that is, their mutual intersections, all parallel.
Thus ir. Fig. 14, on page 6, 0 at top of figure, J2, %}, 0 in front, and
two planes below, and others on the back of the crystal are in one zone,
a vertical zone. Again, in the same figure, 0 at top, 42, 3|, 22, 42, i2, 42,
22, 3:|, and the continuation of this series below and over the back of
the crystal lie in another vertical zone. And so in other cases, in
other directions. All planes in the same zone may be viewed as on the
circumference of the same circle. The planes of crystals are generally
all comprised in a few zones, and the study of the mathematics of
crystals is largely the study of zones of planes.
Axes. — Imaginary lines in crystals intersecting one another at their
centres. Axes are assumed in order to describe the positions of the
planes of crystals. In each system of crystallization there is one verti-
cal axis, and in all but hexagonal forms there are two lateral axes.
Diametral sections. — The sections of crystals in which lie any two of
the axes. In forms having two lateral axes, there are two vertical
diametral sections and one basal.
Diametral prisms. — Prisms whose sides are parallel to the diametral
sections.
Measurement of Angles.
The angles of crystals are measured by means of instruments called
goniometers. These instruments are of two kinds, one the common
goniometer, the other, the reflecting goniometer.
The common goniometer depends for its use on the very simple prin-
ciple that when two straight lines cross one an-
other, as A E, C D, in the annexed figure, the parts
will diverge equally on opposite sides of the point
of intersection (O) ; that is in mathematical lan-
guage, the angle A O D is equal to the angle C O E,
and A O C is equal to D 0 E.
A common form of the instrument is represented in the figure on
page 10.
The two arms a b, c d, move on a pivot at 0, and their divergence,
or the angle they make with one another, is read off on the graduated
arc attached. In using it, press up between the edges a o and c 0,
the edge of the crystal whose angle is to be measured, and con-
tinue thus opening the arms until these edges lie evenly against the
faces that include the required angle. To insure accuracy in this
respect, hold the instrument and crystal between the eye and the light,
and observe that no Jight passes between the arm and the applied faces
of the crystal. The arms may then be secured in position by tighten-
ing the screw at o ; the angle will then be measured by the distance on
the arc from k to the left or outer edge of the arm c d, this edge being in
the line of o. the centre of motion. As the instrument stands in tho
10
CRYSTALLOGRAPHY.
figure, ib reads 45°. The arms have slits at g h, n p, by which the part*
a o, co, may be shortened so as to make them more convenient for
measuring small crystals.
In the best form of the common goniometer the arc is a complete
circle, of larger diameter than in the above figure, and the arms a?e
separate from it. After making the measurement, the arms are laid
upon the circle, with the pivot at the centre of motion inserted in a
socket at the centre of the circle. The inner edge of one of the arms
is then brought to zero on the circle, and the angle is read off as before.
With a Ifttle ingenuity the student may construct a goniometer for
himself tbafc will answer a good purpose. A semicircle may be de-
scribed on mica or a glazed card, and graduated. The arms might also
be made of stiff card for temporary use ; but mica, bone, or metal is
better. The arms should have the edges straight and accurately paral-
lel, and be pivoted together. The instrument may be used like that last
described, and will give approximate results, sufficiently near for dis-
tinguishing most minerals. The ivory rule accompanying boxes of
mathematical instruments, having upon it a scale of sines for measuring
angles, will answer an excellent purpose, and is as convenient as the arc.
In making such measurements it is important to have in mind the
fact that—
1. The sum of the angles about a centre is 360°.
2. In a rhomb, as in a square, the sum of the plane angles is 360°.
In any polygon, the supplements of the Angles equals 360°, whatever
itte number of sides. For example : in a square, the four angles are
each 90°, and hence the supplements are 90°, and 4x90=360 ; again,
in a regular hexagon the six angles are each 120, the supplements are
60°, and 6 x 60—360. So for all polygons, whether regular or irregular.
In measuring the angles it is therefore convenient to take down the
supplements of the angles. This principle is conveniently applied in
the. measurement of all the angles of a zone of planes around the
crystal ; for the sum of all the supplements should be, as abc ve, 380°
and if this result is not obtained there is error somewhere.
CRYSTALLOGRAPHY. 11
The reflecting goniometer affords a more accurate method of
measuring crystals that have lustre, and may be used with those of
minute size. The principle on which this instrument is constructed
will be understood from the annexed figure, representing a crystal,
whose angle a b c is required. The eye, look'
inof at the face of the crystal b c, observes a
reflected image of m, in the direction P n. On
revolving the crystal till a b has the position of
b c, the same image will be seen again in tha
same direction P n. As the crystal is turned,
in this revolution, till a b d has the present
position of b c, the angle d b c measures the number of degrees through
which it is revolved. But d b c subtracted from 180C equals the angle
of the crystal a b c. The crystal is therefore passed, in its revolution,
through a number of degrees equal to the supplement of the required
angle.
This angle, in the reflecting goniometer of Wollaston, is measured
by attaching the crystal to a graduated circle which revolves with it,
one form of which is here represented.
C is the graduated circle. The wheel, m, is attached to the main
ris, and moves the graduated circle together with the adjusted crystal.
12 CBYSTALLOGKAPHY.
The wheel, », is connected with an axis which passes through the
main axis (which is hollow for the purpose), and moves merely the
parts to which the crystal is attached, in order to assist in its adjust-
ment. The contrivances for the adjustment of the crystal are at «, #,
c, d, k. The screws, c, d, are for the adjustment of the crystal, and th«
slides, a, £, serve to centre it.
To use the instrument, it may be put on a stand or small table, with
its base accurately horizontal, and the table placed in front of a win-
dow, six to twelve feet off, with the plane of its circle at right angles
to the window. A dark line must then be drawn below the window,
near the floor, parallel to the bara of the window, and about as far
from the eye as from the window-bar.
The crystal is attached to the movable plate k by means of wax, and
BO arranged that the edge of intersection of the two planes forming the
required angle, shall be in a line with the axis of the instrument.
This is done by varying its situation on the plate, or by means of the
adjacent screws and slides.
When apparently adjusted, the eye must be brought close to the
crystal, nearly in contact with it, and on looking into a face, part of
the window will be seen reflected, one bar of which must be selected
for the trial. If the crystal is correctly adjusted, the selected bar
will appear horizontal, and on turning the wheel n, till this bar, aa
reflected, is observed to approach the dark line below seen in a direct
view, it will be found to be parallel to this dark line, and ultimately to
coincide with it. The eye for both observations should be held in
precisely the same position. If there is not a perfect coincidence, the
adjustment must be altered until this coincidence is obtained. Con-
tinue then the revolution of the wheel n. till the same bar is seen by
reflection in the next face, and if here there is also a coincidence of
the reflected bar with the dark line seen direct, the adjustment is com-
plete ; if not, alterations must be made, and the first face again tried.
In an instrument like the one figured, the circle is usually graduated
to twenty or thirty minutes, and, by means of the vernier, minutes and
half minutes are measured. After adjustment, 180° on the arc must
be brought opposite 0, on the vernier, y>. The coincidence of the bar
and dark line is then to be obtained, by turning the wheel n. When
obtained, the wheel m should be turned until the same coincidence ia
observed, by means of the next fac$, of the crystal. If a line on the
graduated circle now corresponds with 0 on the vernier, the angle is
immediately determined by the number of degrees opposite this line.
If no line corresponds with 0, we must observe wbich line on the
vernier coincides with one on the circle. If it is the 18th on the
vernier, and the line on the circle next below 0 on the vernier marki
125°, the required angle is 125° 18' ; if this latter line marks 125 ° 20 ,
the required angle is 125° 38'.
In the better instruments other improved methods of arrangemei;4
are employed ; and in the best, often called Mitscherlich' s goniometer,
because first devised by him, there are two telescopes, one for passing
a ray of light upon the adjusted crystal, having crossed hair lines in its
focus, and the other for viewing it, also with a hair cross. With such
an arrangement, the window-bur and dark line are unnecessary, the
hair crosses serving to fix the position of the crystal, and the telescopa
that of the eye. If the crystal is perfect in its planes, ar4 the adjust-
CETSTALLOGRAPHY. 13
ment exact, the measurement, with the best instruments, will give the
angle within 10".
Other goniometers have only the second of the two telescopes just
alluded to, as is the case in the figure on page 11. This telescope gives
a fixed position to the eye ; and through it is seen a reflection of some
distant object, which may be even a chimney-top. For the measure-
ment the object, seen reflected in the two planes successively, is
brought each time into conjunction with the hair cross. Exact adjust-
ment is absolutely essential, and with an instrument having the two
telescopes, the first step in a measurement cannot be taken without it.
Only small, well-polished crystals can be accurately measured by the
reflecting goniometer. If, when using the instrument without tele-
scopes, the faces do not reflect distinctly a bar of the window, the flame
of a candle or of a gas-burner, placed at some distance from the crystal,
may be used by observing the flash from it with the faces in succession
as the circle is revolved. A ray of sun-light from a mirror, received on
the crystal through a small hole, may be employed in a similar way. But
the results of such measurements will bo» only approximations. With
two telescopes and artificial light, and with a cross slit to let the light
pass in place of the cross hairs of the first of the above-mentioned tele-
scopes, this light cross will be reflected from the face of a crystal even
when it is not perfect in polish, and quite good results may be obtained.
B. STRUCTURE. — Structure includes cleavage, a characteristic
of crystals intimately connected with their forms and nature.
It is the property, which many crystals have, of admitting ot
subdivision indefinitely in certain directions, and affording
usually even, and frequently polished, surfaces. The direction
is always parallel with the planes of the axes, or with others
diagonal to these.
The ease with which cleavage can be obtained varies greatly
in different minerals, and in different directions in the same
mineral. In a few species, like mica, it readily yields laminae
thinner than paper, and in this case the cleavage is said to be
eminent. Others, of perfect cleavage, cleave easily, but afford
thicker plates, and from this stage there are all grades to that
in which cleavage is barely discernible or difficult. The cleav-
age surfaces vary in lustre from the most brilliant to those that
are nearly dull. When cleavage in a mineral is alike in two or
more directions, that is, is attainable in these directions with
equal facility and affords surfaces of like lustre and character
or marking, this is proof that the planes in those directions are
similar, or have similar relations to like axes. For example,
equal cleavage in three directions, at right angles to one another,
shows that the planes of cleavage correspond to the faces of the
cube ; so equal cleavage in two directions, in a prismatic min-
eral, shows that the planes in the two directions are those of a
CRYSTALLOGRAPHY.
square prism, or else of a rhombic prism ; and if they are at
right angles to one another that they are those of the former.
This subject is further illustrated beyond.
In the following pages (1) the Systems of Crystallization and
the Forms and Structure of Crystals are first considered ; next,
(2) Compound, or Twin Crystals; and then (3) Crystalline
Aggregates.
1. SYSTEMS OF CRYSTALLIZATION: FORMS
AND STRUCTURE OF CRYSTALS.
The forms of crystals are exceedingly various, while the sys-
tems of crystallization, based on their mathematical distinctions,
are only six in number. Some of the simplest of the forma
under these six systems are the prisms represented in the fol-
lowing figures; and by a study of these forms the distinctions
3.
4.
of the six systems will become apparent. These prisms are all
four-sided, excepting the last, which is six-sided. In them the
planes of the top and bottom, and any planes that might be
made parallel to these, are called the based planes, and the sides
the lateral planes. An imaginary line joining the centres of
the bases (c in figures 1 to 8) is called the vertical axis, and the
SYSTEMS OF CRYSTALLIZATION. 15
diagonals a and b, drawn in a plane parallel to the base, are the
lateral axes.
Fig. 1 represents a cube. It has all its planes square (like
fig. 9), and all its plane and solid angles, right angles, and the
three axes consequently cross at right angles (or, in other
9. 10. 11. 12.
noo
words, make rectangular intersections) and are equal. It is an
example under the first of the systems of crystallization, which
system, in allusion to the equality of the axes, is called the
Isometric system, from the Greek for equal and measure.
Fig. 2 represents an erect or right square prism having all its
plane angles and solid angles rectangular. The base is square
or a tetragon, and consequently the lateral axes are equal and
rectangular in their intersections • but, unlike a cube, the verti-
cal axis is unequal to the lateral. There are hence, in the square
prism, axes of two kinds making rectangular intersections. The
system is hence called, in allusion to the two kinds of axes, the
bimetric system, or, in allusion to the tetragonal base, the TQ
tragonal system.
Fig. 3 represents an erect or right rectangular prism, in
which, also, the plane angles and solid angles are rectangular.
The base is a rectangle (fig. 10), and consequently the lateral
axes, connecting the centres of the opposite lateral faces, are un-
equal and rectangular in their intersections ; and, at the same
time, each is unequal to the vertical. There are hence three
unlike axes making rectangular intersections ; and in allusion
to the three unlike axes, the system is called the Trimetric sys-
tem. It is also named, in allusion to its including erect prisms
having a rhombic base, the Orthorhombic system, orthos, in
Greek, signifying straight or erect.
This rhombic prism is represented in fig. 4. It has a rhom-
bic base, like fig. 11 ; the lateral axes connect the centres of the
opposite lateral edges ; and hence they cross at right angles and
are unequal, as in the rectangular prism. This right rhombio
prism is therefore one in system with the right rectangular
prism.
Fig. 5 represents another rectangular prism, and fig. 0
16 CRYSTALLOGRAPHY.
another rhombic prism ; but, unlike figs. 3 and 4, the prisms are
inclined backward, and are therefore oblique prisms. The lat-
eral axes (a, b) are at right angles to one another and unequal,
as in the preceding system ; but the vertical axis is inclined to
the plane of the lateral axes. It is inclined, however, to only
one of the lateral axes, it being at right angles to the other.
Hence, of the three angles of axial intersection, two are rec-
tangular, namely a on 6, and c on b, while one is oblique, ihat is
c (the vertical axis) on a. In allusion to this fact, there being
only one oblique angle, this system is called the Monoclinic sys-
tem, from the Greek for one and inclined.
Fig. 7 represents an oblique prism with a rhomboidal base
(like fig. 12). The three axes are unequal and the three axial
intersections are all oblique. The system is called the Triclinia
system, from the Greek for three and inclined.
Fig. 8 represents a six-sided prism, with the sides equal, and
the base a regular hexagon. The lateral axes are here three in
number. They intersect at angles of 60° ; and this is so,
whether these lateral axes be lines joining the centres of oppo-
site lateral planes, or of opposite lateral edges, as a trial will
show. The vertical axis is at right angles to the plane of the
three lateral axes, inasmuch as the prism is erect or right. The
base of the prism being a regular hexagon, the system is called
the Hexagonal system.
The systems of crystallization are therefore :
I. The ISOMETRIC system : the three axes rectangular in in-
tersections ; equal.
II. The DIMETRIC or TETRAGONAL system : the three axea
rectangular in intersections; the two lateral axes equal, and
unequal to the vertical.
III. The TRIMETRIO or ORTHORHOMBIC system : the three axea
rectangular in intersections, and unequal.
IV. The MONOCJLINIC system : only one oblique inclination
out of the three made by the intersecting axes ; the three axea
unequal.
V. The TRICLINIC system : all the three axes obliquely inclined
to one another, and unequal.
VI. The HEXAGONAL system : the vertical axis at right angles
to the lateral ; the lateral .three in number, and intersecting at
angles of 60°.
These six systems of crystallization are based on mathemati-
cal distinctions, and the recognition of them is of great value
in the study and description of crystals. Yet these distinct iona
are often of feeble importance, since they sometimes separate
SYSTEMS OF CRYSTALLIZATION.
17
species and crystalline forms that are very close in their rela-
tions. There are forms under each of the systems that differ
but little in angles from some of other systems : for example,
square prisms that vary but slightly from the cubic form ; tri-
clinic that are almost identical with monoclinic forms ; hexa-
gonal that are nearly cubic. Consequently it is found that the
same natural group of minerals may include both trimetric and
monoclinic species, as is true of the Hornblende group ; or
monoclinic and triclinic, as is the fact with the Feldspar group,
and so on. It is hence a point to be remembered, when the
affinities of species are under consideration, that difference in
crystallographic system is far from certain evidence that any
species are fundamentally or widely unlike.
L THE ISOMETRIC SYSTEM.
1. Descriptions of Forms. The following are figures of some
of the forms of crystals under the isometric system :
2.
The first is the cube or hexahedron, ai^eady described. Be-
dides the three cubic axes, there are equal diagonals in two
other directions ; one set connecting the apices of the diago-
nally opposite solid angles, four in number (because the number
of such angles is eight), and called the octahedral axes ; and
another set connecting the centres of the diagonally opposite
2
18 CRYSTALLOGRAPHY.
edges, six in number (because the number of edges is twelve)f
and called the dodecahedral axes.
Fig. 2 represents the octahedron, a solid contained undef
eight equal triangular faces (whence the name from the Greek
eight and /ace), and having the three axes like those in the cube.
Its plane angles are 60° ; its interfacial angles, that is the incli-
nation of planes 1 and 1 over an intervening edge (usually written
1 A 1) = 109° 28' ; and 1 on 1 over a solid angle, 70° 32'.
Fig. 3 is the dodecahedron, a solid contained under twelve
equal rhombic faces (whence the name from the Greek for twelve
and face). The position of the cubic axes is shown in the fig-
ure. It has fourteen solid angles ; six formed by the meeting of
four planes, and eight formed by the meeting of three. The
interfacial angles (or i on an adjoining i) are 120° ; i on i over
a four-faced solid angle =90°.
Fig. 4 is a trapezohedron, a solid contained under 24 equal
trapezoidal faces. There are several different trapezohedrons
among isometric crystalline forms. The one here figured, which
is the common one, has the angle over the edge -Z?, 131° 49',
and that over the edge (7, 146° 27'. A trapezohedron is also
called a tetragonal trisoctahedron, the faces being tetragonal
or four-sided, and the number of faces being 3 times 8 (tris,
octo, in Greek).
Fig. 5 is another trisoctahedron, one having trigonal or three-
sided faces, and hence called a trigonal trisoctahedron. Com-
paring it with the octahedron, fig. 2, it will be seen that three
of its planes correspond to one of the octahedron. The same is
true also of the trapezohedron.
Fig. 6 is a tetrahexahedron, that is a 4 X 6-faced solid, the
faces being 24 in number, and four corresponding to each face
of the cube or hexahedron (fig. 1).
Fig. 7 is a hexoctahedron, that is a 6 X 8-faced solid, a pyramid
of six planes corresponding to each face in the octahedron, as is
apparent on comparison. There are different kinds of hexocta-
hedrons known among crystallized isometric species, as well as
of the two preceding forms. In each case the difference is not
in number or general arrangement of planes, but in the angles
between the planes, as explained beyond.
But these simple forms very commonly occur in combination
frith one another ; a cube with the planes of an octahedron and
the reverse, or with the planes of any or all of the other kinds
above figured, and many others besides. Moreover, all stages
between the different forms are often represented among the
crystals of a species. Thus between the cube and octahedron,
ISOMETRIC SYSTEM,
19
occur the forms shown in figs. 8 to 11. Fig. 12 is a cube;
fig. 8 represents the cube with a plane on each angle, equally
inclined to each cubic face ; 9, the same, with the planes on the
angles more enlarged and the cubic faces reduced in size ; and
8.
then 10, the octahedron, with the cubic faces quite small ;
and fig. 11, the octahedron, the cubic faces having disappeared
altogether. This transformation is easily performed by the
student with cubes cut out of chalk, clay, or a potato. It shows
the fact that the cubic axes (fig. 12) connect the apices of the
solid angles in the octahedron.
Again, between a cube and a dodecahedron there occur forma
like figs. 13 and 14 ; fig. 12 being a cube, fig. 13 the same> with
planes truncating the edges, each plane being equally inclined
to the adjacent cubic faces, and fig. 14 another, with these
planes on the edges large and the cubic faces small ; and then,
when the cubic faces disappear by farther enlargement of the
planes on the edges, the form is a dodecahedron, fig. 15. The
student should prove this transformation by trial with chalk or
Borne other material, and so for other cases mentioned beyond*
The surface of such models in chalk may be made hard by a
coat of mucilage or varnish.
Again, between a cube and a trapezohedron there are the
forms 17 and 18 ; 16 being the cube, 17, cube with three planes
placed symmetrically on each angle ; 1 8, the same with the
cubic faces greatly reduced (but also with small octahedral faces),
and 19, the trapezohedron, the cubic faces having disappeared.
CRYSTALLOGRAPHY.
Again, fig. 20 represents a cube with three planes on each
angle, which, if enlarged to the obliteration of the faces of tha
cube, become the trigonal trisoetahedron, fig. 21. So again, fig.
16.
17,
22 represents a cube with six faces on each angle, which, if en«
larged to the same extent as in the last, would become the lex*
octahedron, fig. 23.
Again, fig. 25 is a form between the octahedron (fig. 24) and
dodecahedron (fig. 26) ; and figs. 27 and 28 are forms between
the dodecahedron, fig. 26, and trapezohedron, fig. 29.
ISOMETRIC SYSTEM.
21
Again, fig. 30 is a form between a cube (fig. 16) and a tetra
hexahedron, fig. 31 ; fig. 32, a form between an octahedron, fig.
24, and a tetrahexahedron, fig. 31 ; fig. 33, a form between ai»
octahedron and a trigonal trisoctahedron, fig. 34 ; fig. 35, a form
between a dodecahedron (planes i) and a tetrahexahedron ; fig.
36, a form between the dodecahedron and a hexoctahedron,
fig. 37.
Fig. 38 represents a cube with planes of both the octahedron
»nd dodecahedron.
2, Positions of planes with reference to the axes. Lettering
Of figures. — The numbers by which the planes in the above figures,
and others of the work, are lettered, indicate the positions of the planes
with reference to the axes, and exhibit the mathematical symmetry
And ratios in crystallization. In the figure of the cube (fig. 1) the three
axes are represented ; the lateral semi-axis which meets the front
planes in the figure is lettered «; that meeting the side plane to the
right 6, and the vertical axis c, and the other halves of the same axes
respectively -«, -&, -c. By a study of the positions of the planes of the
22 CRYSTALLOGRAPHY.
cube and other forms with reference to these axes, tho following facti
will become apparent.
In the cube (fig. 1) the front plane touches the extremity of axis «,
but is parallel to axes b and c. When one line or plane is parallel to
another they do not meet except at an infinite distance, and hence the
sign for infinity is used to express parallelism. Employing j, the
initial of infinity, as this sign, and writing c, £, a, for the semi-axes so
lettered, then the position of this plane of the cube is indicated by the
expression ie : ib : la. The top and side-planes of the cube meet one
axis and are parallel to the other two, and the same expression answers
for each, if only the letters «, 6, c, be changed to correspond with their
positions. The opposite planes have the same expressions, except that
the c, &, a will refer to the opposite halves of the axes and be -c, ~b, -a.
In the dodecahedron, fig. 15, the right of the two vertical front planes
t. meets two axes, the axes a and b, at their extremities, and is parallel
to the axis c. Hence the position of this plane is expressed by ic : Ib : la.
So, all the planes meet two axes similarly and are parallel to the third.
The expression answers as well for the planes i in figs. 13, 14, as for that
of the dodecahedron, for the planes have all the same relation to the axes.
In the octahedron, fig. 11, the face 1, situated to the right above,
like all the rest, meets the axes a, b, c, at their extremities ; so that the
expression Ic : Ib : la answers for all.
Again, in fig. 17 (p. 20) there are three planes, 2-2, placed symmet-
rically on each angle of a cube, and, as has been illustrated, these are
the planes of the trapezohedron, fig. 19. The upper one of the planes
2-2 in these figures, when extended to meet the axes (as in fig. 19),
intersects the vertical c at its extremity, and the others, a and 6, at
twice their lengths from the centre. Hence the expression for the plane
is Ic : 2b : 2a. So, as will be found, the left hand plane 2-2 on fig.
17, will have the expression 2c : Ib : 2a; and the right hand one,
2c : 2b : la. Further, the same ratio, by a change of the letters for tho
semi-axes, will answer for all the planes of the trapezohedron.
In fig. 20 there are other three planes, 2, on each of the angles of a
cube, and these are the planes of the trisoctahedron in fig. 21. The
lower one of the three on the upper front solid angle, would meet if
extended, the extremities of the axes a and 6, while it would meet the
vertical axis at twice its length from the centre. The expression
2c : Ib : la indicates, therefore, the position of the plane. So also,
Ic : Ib : 2a and Ic: 2b : la represent the positions of the other two
planes adjoining ; and corresponding expressions may be similarly 3b-
tained for all the planes of the trisoctahedron.
Again, in fig. 30, of the cube with two planes on each edge, and in
fig. 31, of the tetrahexahsdron bounded by these same planes, the left
of the two planes in the front vertical edge of fig. 30 (or the corre-
sponding plane on fig. 31) is parallel to the vertical axis ; its intersections
with the lateral axes, a and b, are at unequal distances from the centre,
expressed by the ratio 2b : la. This ratio for the plane adjoining on
the right is Ib : 2a. The position of the former is expressed by the
ratio ic : 2b : la, and for the other by ic : Ib : 2a. Thus, for each of
the planes of this tetrahexahedron the ratio between two axes is 1 : 2,
while the plane is parallel to the third axis.
Again, in fig., 22, of the cube with six planes on each solid angle, and
in the hexoctahedron in fig. 23, made up of such planes, each of the
planes when extended so that it will meet one axis at once its length
ISOMETKIO SYSTEM. 23
from the centre, will meet the other axes at distances expressed by a
constant ratio, and the expression for the lower right one of the sis;
planes will be Be : f b : la. By a little study, the expressions for the
other five adjoining planes can be obtained, and so also those for all the
48 planes of the solid.
In the isometric system the axes a, 5, c, are equal, so that in the
general expressions for the planes these letters may be omitted ; the
expressions for the above mentioned forms thus become —
Cube (fig. 1), a : 1 : i. Tetrahexahedron (fig. 5), i : 1 : 3.
Octahedron (fig. 2), 1 : 1 : 1. Trigonal trisoctahedron (fig. 6),
Dodecahedron (fig. 3), 1 : 1 : a*. 2:1:1.
Trapezohedron (fig. 4), 2 : 1 : 2. Hexoctahedron (fig. 7), 3 : 1 : $.
Looking again at fig. 17, representing the cube with planes of the trap-
ezohedron, 2 : 1 : 2, it will be perceived that there might be a trap-
ezohedron having the ratios H : 1 : 1|, 3:1:3, 4:1:4, 5:1:5,
and others; and, in fact, such trapezohedrons occur among crystals.
So also, besides the trigonal trisoctahedron 2:1:1 (fig. 21), there
might be, and there in fact is, another corresponding to the expression
8:1:1; and still others are possible. And besides the hexoctahedron
3 : 1 : f (fig. 23), there are others having the ratios 4:1:2, 4 : 1 : $,
5 : 1 : f , and so on.
In the above ratios, the number for one of the lateral axes is always
made a unit, since only a ratio is expressed ; omitting this in the ex-
pression, the above general ratios become : for the cube, i : a'; for the
octahedron, 1:1; dodecahedron, 1 : i ; trapezohedron, 2:2; tetra-
hexahedron, i : 2 ; trigonal-trisoctahedron, 2:1; and hexoctahedron,
3 : f . In the lettering of the figures these ratios are put on the planes,
but with the second figure, or that referring to the vertical axis, first.
Thus the lettering on the hexoctahedron (fig. 23), is 3-|; on the trigonal
trisoctahedron (fig. 21) is 2, the figure 1 being unnecessary ; on the
tetrahexahedron (fig. 31), i-2 ; on the trapezohedron (figs. 4 and 19),
2-2; on the dodecahedron (fig. 15), z; on the octahedron, 1; on the
cube, a'-i, in place of which II is used, the initial of hexahedron. In the
printed page these symbols are written with a hyphen in order to avoid
occasional ambiguity, thus 3-f , i-2, 2-2, etc. Similarly, the ratios
fcr all planes, whatever they are, may be written. The numbers are
usually small, and never decimal fractions.
The angle between the planes i-2 (or a" : 1 : 2) and 0, in fig. 30, page
21, may be easily calculated, and the same for any plane of the series
i-n (i : 1 : ri). Draw the right-angled triangle, A D C,
as in the annexed figure, making the vertical side,
C D, twice that of A C, the base ; that is, give them
the same ratio as in the axial ratio for the plane. If
A'G= 1, CD = 2. Then, by trigonometry, making
AG the radius, 1 : R::2 : tan DAC] or 1 : fi::2: cot
ADC. Whence tan DAG = cot ADC = 2. By ad-
ding to 90°, the angle of the triangle obtained by work-
ing the equation, we have the inclination of the basal
plane 0, or the 0 on the opposite side of the plane a*- 2,
(faces of the cube) on the plane i-2. So in all cases,
whatever the value of ft, that value equals the tangent
of the basal angle of the triangle (or the cotangent of the angle at the
vertex), and from this the inclination to the cubic faces is directly ob-
24 CBYSTALLOGBAPHT.
tained by adding 90°. If n = 1, then the ratio is 1 : 1, as in ACht
and each angle equals 45°, giving 135° for the inclination on eithel
adjoining cubic face.
Again, if the angles of inclination have been obtained by measure-
ment, the value of n in any case may be found by reversing the above
calculation ; subtracting 90° from the angle, then the tangent of this
angle, or the cotangent of its supplement, will equal n, the tangents
Varying directly with the value of n.
la the case of planes of the m : 1 : 1 series (including 1:1:1, 2:1:
1, etc.), the tangents of the angle between a cubic face in the same
zone and theee planes, less 90°, varies with the value of m. In the
case of the plane 1 (or 1:1:1), the angle between it and the cubic face
is 125° 16'. Subtracting 90°, we have 35° 16'. Draw a right-angled
triangle, OBC, with 35° 16' as its vertex angle. BO has
the value of Ic, or the semi-axis of the cube. Make
DC=2BC. Then, while the angle OBC has the value
of the inclination on the cubic face less 90° for the plane
1:1:1, ODC has the same for the plane 2:1:1. Now,
making OC'the radius, and taking it as unity, BG is the
tangent of BOG, or cot OBC . SoDC = 2BC is the tan-
gent of DOC, or cot ODC. By lengthening the side CD
(— 2B C or 2c) it may be made equal to 5BC = 3c, its
value in the case of the plane 3:1:1; or to 4BC — 4e,
its value in the case of the plane 4:1:1; or mBC = me
for any plane in the series m : 1 : 1 ; and since in all
there will be the same relation between the vertical and
the tangent of the angle at the base (or the cotangent of the angle at
the vertex), it follows that the tangent varies with the value of m.
Hence, knowing the value of the angle in the case of the form 1
(1:1:1), the others are easily calculated from it.
BG being a unit, the actual value of 0(7 is | 1/2, or |/jf, it being half the
diagonal of a square, the sides of which are 1, and from this value the
angle 35° 16' might be obtained for the angle OBC.
The above law (that for a plane of the m : 1 : 1 series, the tangent of
its inclination on a cubic face lying in the same zone, less 90°, varies
with the value of m, and that it may be calculated for any plane
m : 1 : 1 from this inclination in the form 1:1:1), holds also for
planes in the series m : 2 : 1, or m : 3 : 1, or any m : n : 1. That is,
given the inclination of 0 on 1 : n : 1, its tangent doubled will be Ctat
of 2 : n : 1, or trebled, that of 3 : n : 1, and so on; or halved, it will be
that of the plane £ : n : 1 , which expression is essentially the same i&
I :2n: 2.
These examples show some of the simpler methods of applying iSia-
thematics in calculations under the isometric system. The values of
the axes are not required in them, because a = b = c — 1.
3. Hemihedral Crystals.— The forms of crystals described
above are called holohedral forms, from the Greek for all and
face, the number of planes being all that full symmetry re-
quires. The cube has eight similar solid angles — similar, that
**, in the enclosing planes and plane angles. Consequently the
l&vt of full symmetry requires that all should have the same
ISOMETRIC SYSTEM.
25
planes and the same number of planes ; and this is the general
law for all the forms. This is a consequence of the equality
of the axes and their rectangular intersections.
But in some crystalline forms there are only half the num-
ber of planes which full symmetry requires. In %. 39 a cube
ia represented with an octahedral plane on half, that is, four, of
39.
the solid angles. A solid angle having such a plane is diag-
onally opposite to one without it. The same form is represented
in fig. 40, only the cubic faces are the smallest ; and in fig. 41
the simple form is shown which is made up of the four octahe-
dral planes. It is a tetrahedron or regular three-sided pyra-
mid. If the octahedral faces of fig. 39 had been on the other
four of the solid angles of the cube, the tetrahedron made of
those planes would have been that of fig. 42 instead of fig. 41.
Other hemihedral forms are represented in figs. 43 to 45 j fig.
43 is a hemihedral form of the trapezohedron, fig. 4, p. 7;
fig, 44, hemihedral of the hexoctahedron, fig. 7, or a hemi-nex-
octahedron. Fig. 45 is a combination of the tetrahedron (plane
1) and hemi-hexoctahedron.
Tn these forms figs. 41-44, no face has another parallel to it;
ami consequently they are called inclined hemihedrons.
Fig. 46 represents a cube with the planes of a tetrahexahe-
dron, as already explained. In fig. 47, the cube has only one
of the plarves i-2 on each edge, and therefore only twelve in all ;
26
CRYSTALLOGRAPHY.
and hence it affords an example of hemihedrism — a kind that is
presented by many crystals of pyrite. Fig. 48 is the hemihe-
46.
dral form resulting when these twelve planes i-2 ave extended
to the obliteration of the cubic faces ; and fig. 49 is another,
made of the other twelve of these planes. Again,
in fig. 50, a cube is represented having only
three out of the six planes of fig. 22, and this
is another example of hemihedrism. These kinds
differ from the inclined hemihedrons in having
opposite parallel faces, and hence they are called
parallel hemihedrons.
4. Internal Structure of Isometric Crystals, or Cleavage. —
The crystals of many isometric minerals have cleavage, or
•*. greater or less capability of division in directions situated
symmetrically with reference to the axes. The cleavage direc-
tions are parallel either to the faces of the cube, the octahe-
dron, or the dodecahedron. In g'alenite (p. 145) there is easy
cleavage in three directions parallel to the faces of the cube ;
in fluonte (p. 208), in four directions parallel to the faces of the
octahedron ; in sphalerite (p. 154), in six directions parallel to
the faces of the dodecahedron. These cleavages are an impor-
tant means of distinguishing the species.
The three cubic cleavages are precisely alike in the ease with
which cleavage takes place, and in the kinds of surface obtained ;
and so is it with the four in the octahedral directions, and the six
in the dodecahedral. Occasionally cleavages of two of these sys-
tems occur in the same mineral ; that is, for example, parallel to
both the faces of the cube and the octahedron ; but when so,
those of one system are much more distinct than those of the
other, and cleavage surfaces in the two directions are quite un-
like as to smoothness and lustre.
5. Irregularities of Isometric Crystals. — A cube has its faces
precisely equal, and so it is with each of the form* v<apresented
ISOMETRIC SYSTEM.
27
in figs. 2 to 7. This perfect symmetry is almost never found
in actual crystals.
61.
62.
53.
I H
H
A cubic crystal has generally the form of a square prism (fig.
51 a stout one, fig. 52 another long and slender), or a rectangu-
lar prism (fig. 53). In such cases the crystal may still be
known to be a cube ; because, if so, the kind of surface and
kind of lustre on the six faces will be precisely alike ; and if
there is cubic cleavage it will be exactly equal in facility in
three rectangular directions ; or if there is cleavage in four, or
BIX, directions, it will be equal in degree in the four, or the six,
directions, and have mutual inclinations corresponding with the
angles of the octahedron or dodecahedron ; and thus the crys-
tal will show that it is isometric in system.
The same shortening or lengthening of the crystal often dia-
55.
57.
guises greatly the octahedron, dodecahedron, and other forma,
This is illustrated in the following figures : Fig. 54 shows the
28
CRYSTALLOGRAPHY.
form of the regular octahedron; 55, an octahedron lengthened
horizontally ; 56, one shortened parallel to one cf the paira
of faces; 57, one lengthened parallel to another pair, the
ultimate result of which obliterates two of the faces, and
places an acute solid angle in place of each. The solid ia
then six-sided, and has rhombic faces whose plane angles are
120° and 60°. The following figures illustrate corresponding
Changes in the dodecahedron (fig. 58). In fig. 59 the dodeca-
hedion is lengthened vertically, making a square prism with four-
sided pyramidal terminations. In 60, it is shortened vertically.
In 61 the dodecahedron is lengthened obliquely in the direction
of an octahedral axis, and in 62 it is shortened in the same
Ji.'ection, making six-sided prisms with trihedral terminations.
So again in the trapezohedron there are equally deceptive
f 'rins arising from elongations and shortenings in the same two
directions.
These distortions change the relative sizes of planes, but not
the values of angles. In crystals of the several forms repre-
sented in figs. 54 to 57, the inclinations are the same as in the
regular octahedron. There is the same constancy of angle in
other distorted crystals.
SYSTEMS OF CRYSTALLIZATION.
Occasionally, as in the diamond, the planes of crystals arc
£onvex ; and then, of course, the angles will differ from the
true angle. It is important, in order to meet the difficulties in
the way of recognizing isometric crystals, to have clearly in the
mind the precise aspoct of an equilateral triangle, which is the
shape of a face of an octahedron ; the form of the rhombic face
of the dodecahedron ; and the form of the trapezoidal face of a
trapezohedron. With these distinctly remembered, isometric
crystalline forms that are much obscured by distortion, or which
show only two or three planes of the whole number, will often
be easily recognized.
Crystals in this system, as well as in the others, often have
their faces striated, or else rough with points. This is gener-
ally owing to a tendency in the forming crystal to make two
different planes at the same time, or rather an
os .'illation between the condition necessary for
making one plane and that for making another.
Fig. 63 represents a cube of pyrite with stri-
ated faces. As the faces of a cube are equal,
the striations are alike on all. It will be noted
that the striations of adjoining faces are at right
angles to one another. The little ridges of the
striated surfaces are made up of planes of the pentagonal dode-
cahedron (fig. 49, p. 26), and they arise from an oscillation in
the crystallizing conditions between that which, if acting alone,
would make a cube, and that which would make this hemihe-
dral dodecahedron. Again, in magnetite, oscillations between the
octahedron and dodecahedron produce the striations in fig. 04.
65.
MAGNETITE.
COMMON SALT.
Octahedral crystals of fluoritc often occur with the facoa
made up of evenly projecting solid angles of a cube, giving
30
CRYSTALLOGRAPHY.
them rough instead of polished planes. This has arisen from
oscillation between octahedral and cubic conditions.
In some cases crystals are filled out only along the diagonal
planes. Fig. 65 represents a crystal of common salt of this
kind, having pyramidal depressions in place of the regular faces.
Octahedrons of gold sometimes occur with three-sided pyram-
idal depressions in place of the octahedral faces. Such forma
sometimes result when crystals are eroded by any cause.
H. DIMETRIC, OR TETRAGONAL SYSTEM.
1. Descriptions of Forms.— In this system (1) the axes cross at
right angles; (2) the vertical axis is either longer or shorter than
the lateral; and (3) the lateral axes are equal.
The following figures represent some of the crystalline forms.
They are very often attached by one extremity to the support-
APOPHYLLITE.
Z1KCON.
fnf rock and have perfect terminating planes only at the other,
Square prisms, with or without pyramidal terminations, square
octahedrons, eight-sided prisms, eight-sided pyramids, and espe-
cially combinations of these, are the common forms. Since the
(atei-al axes are equal, the four lateral planes of the square
prisms are alike in lustre and surface-markings. For the same
reason the symmetry of the crystal is throughout by fours ; that
is, the number of similar pyramidal planes at the extremity iy
cither four or eight; and they show that they are similar by
DniETBIC, OR TETRAGONAL SYSTEM.
31
being exactly alike in inclination to the basal plane as well aa
\like in lustre.
There are two distinct square prisms. In one (fig. 10) the
10.
11.
12.
axes connect the centres of the lateral faces. In the other
(tig. 12) they connect the centres of the lateral edges. In fig.
11 the two prisms are combined; the figure shows that the
planes of one truncate the lateral edges of the other, the inter-
facial angle between adjoining planes being 135°. Figs. 2, 3,
4, 7, are of others having planes of both prisms. In fig. 13 one
prism is represented within the other.
Fig. 14 represents an eight-sided prism, and fig. 15 a combi-
nation of a square prism (i-t) with an eight-sided prism (i-2)
14.
15.
hi*
Another example of this is shown in fig. 4, and also in fig. 9,
the planes i-2 in one, and i-3 in the other.
The basal plane in these prisms is an independent plane, be-
cause the vertical axis is not equal to the lateral, and hence it
almost always differs in lustre and smoothness from the lateral.
Like the square prisms, the square octahedrons are in two
series, one set (fig. 16) having the lateral or basal edges parallel
to the lateral axes, and these axes connecting the centres of
opposite basal edges, and the other (fig. 17) having them diago-
nal to the axes, these axes connecting the apices of the opposite
32
CRYSTALLOGRAPHY.
solid angles, as in the isometric octahedron. There may be, on
the same crystal, faces of several octahedrons of these two series,
differing in having their planes inclined at different angles to
16.
the basal plane. In figs. 5 and 7 there is one of these pyra-
mids terminating the prism, and in figs. 6 and 8 the planes
of two. In figs. 1 to 3 there are planes of the same octahe-
dron, but combined with the basal plane O ; and in fig. 4 there
are planes of two, with 0. In fig. 9 there are planes of the
same octahedron, with planes of a square prism (i-i), and of an
eight-sided prism (i-2). In fig. 18 there is the prism i-i com-
bined with two octahedrons, and the basal plane 0 ; and in
19 the planes of one octahedron with the prism I.
Fig. 20 represents an eight-sided double pyramid, made of
21.
equal planes, equally inclined to the base ; and fig. 21, the
planes on the square pri#m i-i. The small planes, in pairs, on
fig. 8, are of this kind. In fig. 22 the small planes 3-3 of
fig. 8 occur alone, without planes of the four-sided pyramids,
and therefore make the eight-sided pyramid, 3-3.
This solid of sixteen planes has the largest number of similar
planes possible in the dimetric system, while the largest number
in the isometric system (occurring in the hexoctahedron) is
forty-eight.
DIMETRIC, OK TETRAGONAL SYSTEM. 33
2. Positions of the Planes with reference to the Axes.— Let-
tering of planes. In the prism fig. 10, the lateral planes are parallel to
fche vertical axis and to one lateral axis, and meet the other lateral axis
at its extremity. The expression for it is hence (c standing for the
vertical axis and a, b for the lateral) ic : ib : la, i, as before, standing
for infinity and indicating parallelism. For the prism of fig. 12, the
prismatic planes meet the two lateral axes at their extremities, and
are parallel to the vertical, and
hence the expression for them is 23.
X5 : \b : la. In the annexed figure
the two bisecting lines, a —a and
b ~-b, represent the lateral axes;
the line s t stands for a section of
a lateral plane of the first of these ~b •
prisms, it being parallel to one
lateral axis and meeting the othei
at its extremity, and ab for that -
of the other, it meeting the two
at their extremities.
In the eight-sided prisms (figs. 14, 15), each of the lateral planes is
parallel to the vertical axis, meets one of the lateral axes at its extrem-
ity, and would meet the other axis if it were prolonged to two or three
or more times its length. The line ao, in fig. 23, has the position of one
of the eight planes ; it meets the axis b at 0, or twice its length from
the centre ; and hence the expression for it would be ic : 2b : la, or,
since b = a, ic : 2 : 1, which is a general expression for each of the eight
planes. Again, op has the position of one of the eight planes of an-
other such prism ; and since Op is three times the length of 06, the ex-
pression for the plane would be ic : 3 : 1. So there may be other eight-
sided prisms ; and, putting n for any possible ratio, the expression
ic : n : 1 is a general one for all eight-sided prisms in the dimetric sys-
tem.
A plane of the octahedron of fig. 16 meets one lateral axis at its
extremity, and is parallel to the other, and it meets the vertical axis c
at its extremity ; its expression is consequently (dropping the letters a
and £, because these axes are equal) Ic : i : I. Other octahedrons in
the same vertical series may have the vertical axis longer or shorter
than axis c ; that is, there may be the planes 2c : t : 1, Sc : i : 1,
4c : i : 1, and so on ; or \c : i : 1, £c : i : 1, and so on ; or, using m for
any coefficient of c, the expression becomes general, me : i : 1. When
m = 0 the vertical axis is zero, and the plane is the basal plane 0 of
the prism ; and when m = infinity, the plane is ic : i : 1, or the vertical
plane of the prism in the same series, i-a, fig. 10.
The planes of the octahedron of fig. 17 meet two lateral axes at their
extremities, and the vertical at its extremity, and the expression for the
plane is hence Ic : 1 : 1. Other octahedrons in this series will have the
tpression me : 1 : 1, in which m may have any value, not a
greater or less than unity, as in the preceding case. When in
this series m — infinity, the plane is that of the prism ic : 1 : 1, or that
of fig. 12.
In the case of the double eight-sided pyramid (figs. 20, 21, 22),
the planes meet the two lateral axes at unequal distances from the
centre ; and also meet the vertical axis. The expression may \x
34: CRYSTALLOGRAPHY.
2o : 2 : 1, 4<5 : 2 : 1, 5c : 3 : 1, and so on; or, giving it a general form,
me : n : 1.
In the lettering of the planes on figures of dimetric crystals, the first
number (as in the isometric and all the other systems) is the coefficient
of the vertical axis, and the other is the ratio of the other two, and
when this ratio is a unit it is omitted.
Tke expressions and the lettering for the planes are then as follows :
Expressions. Lettering.
For square prisms j J; £ | * ; J ^ f
For eight-sided prisms ic : n : I i-n
For octahedron, { '; ™\{\\ <?
For double eight-sided pyramids, me : n : I m-n
The symbols are written without a hyphen on the figures of crystals.
On figure 14, the plane i-n is that particular i-n in which n r= 2, or i-2.
In fig. 21 the planes of the double eight-sided pyramid, m-n, have
m = 1 and n = 2 (the expression being 1:2:1), and hence it is lettered
1-2. In fig. 8 and in fig. 22 it is the one in which m = 3 and n = 3
(the expression being 3:3:1), and hence the lettering 3-3.
The length of the vertical axis c may be calculated as follows, pro-
vided the crystal affords the required angles :
Suppose, in the form fig. 18, the inclination of 0 on plane l-i to have
been found to be 130°, or of iri on the same plane, 140° (one follows
from the other, since the sum of the two, as has been explained, is
necessarih 370'). Subtracting 90°, we have 40° for the inclination of
the plane on the vertical axis c, or 50 D for the same on the lateral axis?
a, or the basal section, [n the right-angled triangle, OBG, the angle
OBG equals 40°. If 0 G be taken as a = 1, then BG will
be the length of the vertical axis c • and its value may be
obtained by the equation cot 40° = BG, or tan 50° = BG.
On fig. 18 there is a second octahedral plane, lettered
\-i, and it might be asked, Why take one plane rather
than the other for this calculation ? The determination
on this point is more or less arbitrary. Ifc is usual to
assume that plane as the unit plane in one or the other
series of octahedrons (fig. 16 or fig. 17) which is of most
common occurrence, or that which will give the simplest
symbols to the crystalline forms of a species ; or that
which will make the vertical axis nearest to unity ; or
that which corresponds to a cleavage direction.
The value of the vertical axis having been thus deter-
Q ined from \ i, the same may be determined in like manner for -J-* in
uKe same figure (fig. 18). The result would be a value just half that of
BC. Or if there were a plane 2-», the value obtained would be twice
BG, or BD in fig. 24; the angle ODG + 90° would equal the inclina-
tion of 0 on 2-i. So for other planes in the same vertical zone, aa 3-»,
4-/, or any plane m-i.
If there were present several planes of the series m-i, and their incli-
35
lations to the basal plane O were known, then, after subtracting from
the values 90°, the cotangents of the angles obtained, or the tangents
of their complements, will equal m in each case ; that is, the tangents
(or cotangents) will vary directly with the value of m. The logaritl .m
of the tangent for the plane 1-i, added to the logarithm of 2, will
equal the logarithm of the tangent for the plane 2-i, and so on.
The law of the tangents for this vertical zone m-i holds for the planes
of all possible vertical zones in the dimetric system. Further, if the
•qaare prism were laid on its side so that one of the lateral planes be-
came the base, and if zones of planes are present on it that are vertical
with refe;ence to this assumed base, the law of the tangents still holds,
with onlj this difference to be noted, that then one of the lateral axea
is the vertical. It holds also for the trimetric system, no matter which
of the diametral planes is taken for the base, since all the axial inter-
sections are rectangular. It holds for the monoclinic system for the
zone of planes that lies between the axes c and b and that between the
axes a and b, since these axes meet at right angles, but not for that
between c and a, the angle of intersection here being oblique. It holds
for all vertical zones in the hexagonal system, since the basal plane iu
this system is at right angles to the vertical axis. But it is of no use
in the tridinic system, in which all the axial intersections are oblique.
The value of the vertical axis c may be calculated also from the incli-
nation of 0 on 1, or of /on 1. See tig. 2, and compare it with fig. 17.
If the angle /on 1 equals 140°, then, after subtracting 90°, we have 50°
for the basal angle in the triangle 0GB, fig. 24 ; or for half the inter-
facial angle over a basal edge— edge Z— in fig. 17. The value of Q
may then be calculated by means of the formula
by substituting 50° for %Z and working the equation.
For any octahedron in the series in, the formula is
Z being the angle over the basal edge of that octahedron. If m •= 2,
then c = | (tan iZvi). Further, m = (tan \Z f£) -f- c.
The interfacial angle over the terminal edge of any octahedron m
may be obtained, if the value of c is known, by the formulas
me =• cot c cos e = cot $X
X being the desired angle (fig. 17). The same for any octahedron m~i
may be calculated from the formulas
me = cot € cos e = cos | T V 2
Ir being the desired angle (fig. 16).
For other methods of calculation reference may be made to the " Text
Book of Mineralogy," or to some other work treating of mathematical
crystallography.
3. Hemihedral Forms.— Among the few hemihedral forma
nuder the dimetric system there is a tetrahedron, called a sphen*
36
CRYSTALLOGRAPHY.
old (figs. 25 or 26), and also forms in which only half of the
sixteen planes of the double eight-sided pyramid, or half the
eight planes of an eight-sided prism — those alternate in position
are present (ligs. 27, 28). In fig. 27 the absent planes are
those of half the pairs of planes ; and in fig. 28 they include
one of each of the pairs, as will be seen on comparing these
figures with fig. 21.
4. Cleavage. — In this system cleavage may occur parallel to the
sides of either of the square prisms ; parallel to the basal plane ;
parallel to the faces of a square octahedron ; or in two of these
directions at the same time. Cleavage parallel to the base and
that parallel to a prism are never equal, so that such prisms
need not be confounded with distorted cubes.
5. Irregularities in Crystals. — The square prisms are very
often rectangular instead of square, and so with the octahedrons.
But, as elsewhere among crystals, the angles remain constant.
When forms are thus distorted, the four prismatic planes will have
like lustre and surface markings, and thus show that the faces
are normally equal and the lateral axes therefore equal. If
the plane truncating the edge of a prism makes an angle of
precisely 135° with the faces of the prism, this is proof that
the prism is square, or that the lateral axes are equal, since the
angle between a diagonal of a square and one of its sides is 45°,
and 135° is the supplement of 45°.
6. Distinctions. —The dimetric prisms have the base different
in lustre from the sides, and planes on the basal edges different
in angle from those on the lateral, and thus they differ frona
isometric forms. The lateral edges may be truncated, and the
new plane will have an angle of 135° with those of the prism,
in which they differ from trimetric forms, while like isometric.
The extremities of the prism, if it have any planes besides the
basal, will have them in fours or eights, each of the four, or
of the eight, inclined to the base at the same angle. When
there is any cleavage parallel to the vertical axis, it is alike
TRIMETRIC, OR ORTHORHOMBIC SYSTEM. 37
in two directions at right angles with one another. The
lateral planes of either square prism are alike in lustre and
markings.
III. TRIMETRIC, OR ORTHORHOMBIC SYSTEM.
1. Descriptions of Forms. — The crystals under the trimotrio
eystem vary from rectangular to rhombic prisms and rhombic
octahedrons, and include various combinations of such forms.
Figs. 1 to 7 are a few of those of the species barite, and figs. 8
to 10 of crystals of sulphur.
4.
BARITE.
SULPnUH.
Fig. 11 represents a rectangular prism (diametral prism),
and fig. 12 a rhombic p.iism, each with the axes. The axes
connect the centres of the opposite planes in the former ; but
in the latter the lateral axes connect the centres of the oppo-
site edges. Of the two lateral axes the longer is called the
nuicrodiagonal, and the shorter tne br achy diagonal. The verti-
cal section containing the former is the macrodiagonal section
and that containing the latter, the br achy diagonal section.
In the rectangular prism, fig. 11, only opposite planes are alike,
because the three axes are unequal. Of these planes, that oppo-
site to the larger lateral axis is called the macropinacoid, and
that opposite the shorter the brachypinacoid (from the Greek for
long and short, and a word signifying board or table).
CRYSTALLOGRA PUT.
pair — that is, one of these planes and its opposite — is called a
hemiprism .
In the rhombic prism, fig. 12, the four lateral planes are
similar olanes. But of the four lateral edges of the prism two
11.
12.
are obtuse and two acute. Fig. 13 represents a combination of
the rectangular and rhombic prisms, and illustrates the rela-
tions of their planes. Other rhombic prisms parallel to the
vertical axis occur, differing in interfacial angles, that is, in the
ratio of the lateral axes.
Besides vertical rhombic prisms, there are also horizontal
prisms parallel to each lateral axis, a and b. In fig. 2 the narrow
planes in front (lettered $i) are planes of a rhombic prism parallel
to the longer of the lateral axes, and those to the right (H) are
planes of another parallel to the shorter lateral axis. In fig. 6
the planes are those of these two horizontal prisms. Such
prisms are called also domes, because they have the form of the
roof of a house (domus in Latin meaning house). In fig. 3
these same two domes occur, and also the planes (lettered I) of
a vertical rhombic prism. Of these domes there may be many
both in the macrodiagonal and the brachydiagonal series, differing
in angle (or in ratio of the two intersected axes). Those par-
allel to the longer lateral axis, or the macrodiagonal, are called
macrodomes ; and those parallel to the shorter, or brachydiag-
onal, are called br achy domes.
A rhombic octahedron, lettered 1, is shown in fig. 8 ; a com-
bination of two, lettered 1 and -J, in tig. 9 ; and a combination
of four, lettered 1, J, -J-, -J-, in fig. 10. This last figure contains
also the planes I, or those o£ a vertical rhombic prism; the
planes 1-&, or those of a dome parallel to the longer lateral axis ;
ihe planes 14, or those of a dome parallel to the shorter lateral
axis ; the plane 0, or the basal plane ; the plane i-i, or the
brachypinacoid ; and also a rhombic octahedron lettered 1-3.
2. Positions of Planes. Lettering of Crystals. — The notation
is, in a general way, like that of the diraetric system, but with differ-
ences made necessary by the inequality of the lateral axes. The letter!
TRIMKTRIC, OR ORTHORHOMBIO SYSTEM. 39
for the three are written c : t> : a ; I being the longer lateral and a the
Bhortei lateral. In place of the square prism of the dimetric system,
i-i, there are the hemiprisms i-i and a-i, or the macropinacoid and brachy-
pinacoid, having the expressions ic : ib : Id and ic :_ll : id. The form/
is the rhombic prism, having the expression ic : \6 : \a, corresponding
to the square prism / in the dimetric system. The planes i-n or i-n
are other rhombic vertical prisms, the former corresponding to
ic : nb : \a, the other to ic : \b : ua. If » = 2, the plane is lettered
either i-2 or t-S. The plane 1*3 has the expression Ic : \b : 3d. m-n
and m-n comprise all possible rhombic prisms and octahedrons, and
correspond to the expressions me : nb : Id and me : \.b : nu. When m =
infinity they become i-fi and i-h, or expressions for vertical rhombic
prisms ; when n = infinity they become m-l and m-i, or expressions for
macrodomes and brachydomes.
The question which of the three axes should be taken as the vertical
axis is often decided by reference simply to mathematical convenience.
Sometimes the crystals are prominently prismatic only in one direction,
as in topaz, and then the axis in this direction is made the vertical. In
many cases a cleavage rhombic prism, when there is one, is made the
vertical, but exceptions to this are numerous. There is also no general
rule for deciding which octahedron should be taken for the unit octahe-
dron. But however decided, the axial relations for the planes will re-
zuain essentially the same. In fig. 10, had the plune lettered | been
made the plane 1, then the series, instead of being as if is in the figure,
1» ij i> &•> would have been 2, 1, f, f, in which the mutual axial rela-
tions are the same.
The relative values of the axes in the trimetric system may be calcu-
lated in the same way as that of the vertical axis in the dimetric sys-
tem, explained on page 34. The law of the tangents, as stated on page
35, holds for this system.
3. Hemihedral Forms. — Hemihedral forms are not common
in this system. Some of those so considered have been proved
to owe their apparent hemiliedrism to their being of the mono-
clinic system, as in the case of datolite and two species of the
fchondrodite group. In a few kinds, as, for example, calaimne,
one extremity of a crystal differs in its planes from the other.
Such forms are termed hemimorphic, from the Greek for half
and form. They become polar electric when heated, that is,
are pyroelectric, showing that this heraimorpliism is connected
with polarity in the crystal.
4. Cleavage. — Cleavage may take place in the direction Df
either of the diametral planes (that is, either face of the rectan-
gular prism) ; but it will be different in facility and in the sur-
face afforded for each. In anhydrite, however, the difference is
very small. Cleavage may also occur in the direction of the
planes of a rhombic prism, either alone or in conr.ection with
cleavage in other directions. It also sometimes occurs, as in
sulphur, parallel to the faces of a rhombic octal uxlron.
4rO CKYSTALLOGKAPH1.
5. Irregularities in Crystals. — The crystals almost never cor-
respond in their diametral dimensions with the calculated axial
dimensions. They are always lengthened, widened, shortened,
or narrowed abnormally, but without affecting the angles. Ex-
amples of diversity in this kind of distortion are given in figs.
1 to 7, of barite.
6. Distinctions. — In the trimetric system the angle 135° doea
not occur, because the three axes are unequal. There are pyra-
mids of four similar planes in the system, but never of eight ;
and the angles over the terminal edges of the pyramids are
never equal as they are in the dimetric system. The rectangu-
lar octahedron of the trimetric system is made up of two hori-
zontal prisms, as shown in fig. 6, and is therefore not a simple
form ; and it differs from the octahedron of the dimetric sys-
tem corresponding to it (fig. 16, p. 32) in having the angles
over the basal edges of two values.
IV. MONOCLINIC SYSTEM.
1. Descriptions of Forms. — In this system the three axes are
unequal, as in the trimetric system ; but one of the axial inter-
sections is oblique, that between the axis a ^vnd the vertical axis
c. The following examples of its crystalline forms, figs. 1 to 6,
show the effect of this obliquity. On account of it the front
or back planes above and below the middle in these figures
differ, and the anterior and posterior prismatic planes are une-
qually inclined to a basal plane.
2.
PYROXENE.
HORNBLENDE.
The axes and their relations are illustrated in figs. 7 and 8.
Fig. 7 represents an oblique rectangular prism, and fig. 8
an oblique rhombic. The former is the diametral prism, like
the rectangular of the trimetric system. The axes connect
the centre* of the opposite faces, and the planes are of three
MONOCLINIO SYSTEM. 41
distinct kinds, being parallel to unlike axes and diametral sec-
tions. In the latter, as in the trimetoi:; ihombic prism, the
lateral axes connect the centres of the opposite sides. More-
over, this rhombic prism may be reduced to the rectangular by
the removal of its edges by planes parallel to the lateral axes.
6.
MIBABILITB.
The axis a, or the inclined lateral axis (inclined at an oblique
angle to the vertical axis c), is called the clinodiagonal ; and the
axis 6, which is not inclined, the ortJiodiagonaL (from the Greek
for right, or rectangular). The vertical section through tho
former is called the dinodiagonal section / it is parallel to the
plane i-l (fig. 1-6). The vertical section through the latter is
iLe orthodiagonal section ' it is parallel to planes i-i. Owing to
the oblique angle between a and c, the planes above a differ
in their relations to the axes from those below, and hence comes
the difference in the angle they make with the basal plane.
The halves of a crystal either side of the clinodiagonal section
— tho vertical section through a and c — are alike in all planes
and angles. Another important fact is this : that the plane i-l,
or that parallel to the clinodiagonal section, is at right angles not
only to O and i-i, but to all planes in the zone of O and i-i '
42 CRYSTALLOGBAPHT.
that is, in the clinodiagonal zone ; and this is a consequence of
the right angle which axis b makes with both axis c and axis cu
The plane i-i is called the orthopinacoid, it being parallel to the
orthodiagonal ; and the plane i-l, the clinopinacoid, it being
parallel to the clinodiagonal.
Vertical rhombic prisms have the same relations to the lateral
axes as in the trimetric system. Domes, or horizontal rhombic
prisms, occur in the orthodiagonal zone, because the vertical
axis c and the orthodiagonal b make right angles with one
another. In fig. 6 the planes 1-i, 2-i belong to two such
domes. They are called clinodomes, because parallel to the
clinodiagonal.
In the clinodiagonal zone, on the contrary, the planes above
and below the basal plane differ, as already stated, and hence
there can be no orthodomes ; they are hemiorthodomes. Thus,
in fig. 6, %-i, l-i are planes of hemiorthodomes above i-i, and
— J-i is a plane of another of different angle below i-i. The
plane, and its diagonally opposite, make the hemiorthodome.
The octahedral planes above the plane of the lateral axes also
differ from those below. Thus, in tigs. 5 and 6, the planes 1, 1
are, in their inclinations, different planes from the planes — 1,
— 1 ; so in all cases. Thus there can be no monoclinic octahedrons
— only hemioctahedrons. An oblique octahedron is made up of
two sets of planes; that is, planes of two hemioctahedrons.
Such an octahedron may be modelled and figured, but it will
consist of two sets of planes : one set including the two above
the basal section in front and their diagonally opposites behind
(fig. 9), and the other set including the two below the basal sec-
tion and their diagonally opposites (fig. 10).
A heiuioctahedron, since it consists of only four planes, ia
really an obliquely placed rhombic prism, and very frequently
they are so lengthened as to be actual prisms.
TRICLINIO SYSTEM. 43
2 Positions of Planes. Lettering of Crystals On account oi
the obliquity of the crystals, the planes above and below the basal sec-
tion require a distinguishing mark in their lettering, as well as in the
mathematical expressions for them. One set is made minus and the
other plus. The plus sign is omitted in the lettering. In fig. 7 there
are above the basal section (or above i-i) the planes 1-z, £-z, 1, |, but bo-
low it, — $•-»', — 1. T he plus planes are those opposite the acute inter-
section of the basal and orthodiagonal sections, and the minus those
opposite the obtuse. No signs are needed for planes of the cliuodiago-
nal section, since they are alike both above and below the basal sec-
tion.
The distinction of longer and shorter lateral axis is not available :u
this system, since either may be the clinodiagonal. The distinction of
clinodiagonal and orthodiagonal planes is indicated by a grave accent
over the number or letters referring to the clinodiagonal. The lettering
for the cliuodomes on fig. 6 is l-l, 2-1 — the i (initial of infinite, with
the accent) signifying parallelism to the cfm<?diagonal. The hemiocta-
hedrons, 1, 2, etc., need no such mark, as the expression for them
is \c : 1 b : id, 2c : Ib : Id, the planes having a unit ratio for d and b.
But the plane 2-$, in fig. 5, requires it, its expression being 2c : \b : 2d\
the fact that the last 2 refers to the clinodiagonal is indicated by
the accent. If it referred to the orthodiagonal, that is, if the expres-
sion for the plane were 2c : 2b : Id, it would be written 2-2 without the
accent.
3. Cleavage. — Cleavage may be basal, or parallel to either of
the other diametral sections, or parallel to a vertical rhombic
prism, or to the planes of a hemioctahedron ; or to the planes of
a clinodorne, or to that of a hemiorthodome. If occurring in two
or more directions in any species it is always different in degree
in each different direction, as in all the other systems.
4. Irregularities. — Crystals of this system may be elongated
abnormally in the direction of either axis, and any diagonal.
The hemiorthodomes may be in aspect the bases of prisms, and
the hemioctahedrons the sides of prisms. Which plane in the
zone of hemiorthodomes should be made the base, and which in
the series of hemioctahedrons should be assumed as the funda-
mental prism determining the direction of the vertical axis, ia
often, decided differently by different crystallographers. Con-
venience of mathematical calculation is often the principal point
referred to in order to reach a conclusion.
V. TRICLINIC SYSTEM.
1. Descriptions of Forms. — In the triclinic system the three
axes are unequal and their three intersections are oblique, and
consequently there are never more than two planes of a kind j
44
CRYSTALLOGRAPHY.
that is, planes having the same inclinations to cither diamotral
section. The following are examples :
AXINITE.
ANORTHITE.
AMBLYGONITE.
The difference in angle from monoclinic forms is often very
small. This is true in the Feldspar family. Fig. 2, of the
feldspar called anorthite, is very similar in general form to
fig. 4, of orthoclase, which is monoclinic. This is still more
strikingly seen on comparing fig. 4 with fig. 5, representing
a crystal of oligoclase, another one of the triclinic feldspars. The
ORTHOCLASE.
OLIGOCLASE.
planes on the two are the same with one exception; but there
is this difference, that in orthoclase, as in all monoclinic crys-
tals, the angle between the planes 0 and i-l (the two directionji
HEXAGONAL SECTION OF HEXAGONAL SYSTEM. 45
of cleavage) is 90° ; and in oligoclase and the other triclinio
feldspars it is 3° to 5° from 90°, being in oligoclase 93° 50', and
in anorthite 94° 10'. This difference in angle involves oblique
intersections between the axes b and c, and c and a, which are
rectangu lar in moiioclinic forms. There is a similarly close ro
lation be JT^een the triclinic form of rhodonite and that of pyrox-
ene, and a resemblance also in composition.
The diametral prism in this system is similar to fig. 7 on
page 41, under the monoclinic system, but differs in having the
planes all rhomboidal instead of part rectangular. The form
correspond vug to the oblique rhombic prism of the monoclinic
system (fig. 8, p. 41) also has rhon«boidal instead of rhombic
planes ; moreover, the two prismatic planes have unequal in-
clinations to the vertical diametral section, and are therefore
dissimilar planes. The prism, consequently, is made of two
hemiprisms, and the basal plane is another, making in all three
heiniprisms.
2. Cleavage. — Cleavage takes place independently in differ-
ent diametral or diagonal directions. In the triclinic feldspars
it conforms to the directions in orthoclase, with only the excep-
tion arising from the obliquity above explained.
VI. HEXAGONAL SYSTEM.
This system is distinguished from the others by the charac-
ter of its symmetry — the number of planes of a kind around
the vertical axis being a multiple of 3. The number of lateral
axes is hence 3. It is related to the dimetric system in having
the lateral axes at right angles to the vertical and equal, and is
hence like it also in the optical characters of its crystals. Its
hexagonal prismatic form approaches trimetric crystals in the
obtuse angle (120°) of the prism, some trimetric crystals having
in angle of nearly 1 20°.
Under this system there are two sections :
1. The HEXAGONAL SECTION, in which the number of planes
of a kind around each vertical axis above or below the basal
section is 6 or 12.
2. The RHOMBOHEDRAL SECTION, in which the number of
planes of a kind around each half of the vertical axis, above rjr
below the basal section, is 3 or 6 ; and, in addition, the planes
above are alternate in position with those below. The forms
are mathematically hemihedral to the hexagonal, Vut not so
in their real nature.
CRYSTALLOGRAPHY.
I. HEXAGONAL SECTION.
1. Description of Forms. — Figs. 1 to 3 represent some of th«
forms under this section. Figs. 2 and 3 show only one ex-
MIMETITE.
BERYL.
APATITE.
fcremity; and such crystals are seldom perfect at both. All
exhibit well the symmetry by sixes which characterizes this
section of the hexagonal system.
7.
/
/
^jj
jj
J*risms. Under this system there are two hexagonal prisms
•lid a number of occurring twelve-sided prisms. Fig. 4 repre-
sents one of the hexagonal prisms, with its axes — the three
lateral connecting the centres of the opposite edges. Tho
lateral angles of the prism are 120°. If the lateral edges of
this prism are truncated, as in the figure of apatite (fig. 3), the
truncating planes, i-2, are the lateral faces of another similar
hexagonal prism, in which, as the relations of the two show, the
HEXAGONAL SECTION OF HEXAGONAI SfSTEM.
8.
lateral axes connect the centres of the opposite lateral faces.
This prism is represented in fig. 5.
The lateral edges of the hexagonal prisms occur sometimes
with two similar planes on each edge, and these planes, wheu
extended to the obliteration of the hexagonal prism, make
% twelve-sided prism. These two
planes are seen in fig. 8, along
with the planes I of the hexago-
nal prism, and 1 of a double six-
sided pyramid, besides the basal
plane 0.
Double pyramids. The double
pyramids are of three kinds: (1)
A series of sij:-sided, whose planes belong to the same verti-
cal zone with the planes I. The planes of two such pyramids
(lettered 1, 2) are shown in figs. 1 and 2, three of them in fig.
3 (lettered £, 1, 2), and one in fig. 7, and one such double
pyramid, without combination with other planes, in fig. 6.
(2) A series of six-sided double pyramids, whose planes are iu
the same vertical zone with i-2, examples of which occur on fig.
2 (plane 2-2)— on fig. 3 (planes 1-2, 2-2, 4-2). The form of this
double pyramid is like tha^epresented in fig. 6, but the lateral
axes connect the centres 01 the basal edges. The double six-
sided pyramid is sometimes called a quartzoid, because it occurs
in quartz. (3) Twelve-sided double pyramids. Two planes of
en ch a pyramid are shown on a hexagonal prism in fig. 9, also in
fig. 2 (the planes 3- j), and the simple form consisting of such
planes in fig. 10 — a form called a beryttoid, as the planes are
common in beryl. In fig. 1 1 the planes 1 bel Mig to a double
six-sided pyramid ; and those next below (of which three are
lettered W) to a double twelve-sided pyramid.
CRYSTALLOGRAPHY.
2. Lettering Of Crystals.— The prism of fig. 5 is lettered a-2, be-
cause it is parallel to the vertical axis, and has the ratio of 1 : 2 between
two lateral axes. This is shown in the annexed figure, which repre-
sents the hexagonal outline of tlie prism
i-2 circumscribing that of the prism /.
The plane i-2 is produced to meet axis
«, which it does when a is extended to
twice its length ; whence the ratio for
the axes a, a', is 1 : 2.
The numbers 1, 2, on the double hexa-
gonal pyramids in fig. 1 indicate the
relative lengths of the vertical axis
of the two pyramids, they having the
same 1 : 1 ratio of the lateral axes ; and
so in figs. 2, 3, and others.
The lettering on the pyramids of the other series in fig. 3, 1-2, 2-2,
4-2, indicates, by the second figure, that the planes ^pxe in the same
vertical zone with the prismatic plane *-2, and by the first figure the rel-
ative lengths of the vertical axes.
In the twelve-sided prisms such ratios as &-f, i-§, £-£ occur. The
fraction in any case expresses the ratio of the lateral axes for the par-
ticular planes. The double twelve-sided pyramids have the ratios 3-|
(fig. 2), 4-ij-, and others. Both in these forms and the twelve-sided
prisms, the second figure in the lettering, expressing the ratio of the
lateral axes, has necessarily a value between 1 and 2.
3. Kemihedral Forms. — Fig. 1 Represents a crystal of apa-
tite in which there are two sets cf planes, o (=3-|) and 0' (=-
which are hemihedral, only half of
the full number of each o existing
instead of all. This kind of hemi-
hedrism consists in the suppression
of an alternate half of the planes
in each pyramid of the double
twelve-sided pyramid (fig. 10), and
in the suppressed planes of the
upper pyramid being here directly
over those suppressed in the lower
pyramid. If the student will shade
oror half the plai>3y alternately of
the two pyramids, putting the
shaded planes above directly over
those below, he will understand the nature of the hemihedrism.
In some hemihedral forms the suppressed planes of the upper
pyramid alternate with those of the lower ; but this kind
occurs only in the rhombohedral section of the hexagonal
system.
4. Cleavage. — Cleavage is usually basal, or parallel to a six
APATITE.
KHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM
14.
sided pyramid. Sometimes there are traces of cleavage parallel
to the faces of a six-sided pyramid.
5. Irregularities of Crystal-
Distortions sometimes disguise
greatly the real forms of hexagonal
Crystals by enlarging some planes
At the expense of others. This is
illustrated in fig. 14, representing
the actual form presented by a
crystal having the planes shown
in fig. 13. Whenever in a prism
the prismatic angle is exactly 120°
or 150°, the form is almost always
of the hexagonal system.
2. RHOMBOHEDRAL SECTION.
1. Descriptions of Forms. — The following figures, 1 u> 17,
represent rhombohedral crystals, and all are of one mineral, cal-
cite. They show that the planes of either end of the crystal
are in threes, or multiples of threes, and that those above are
alternate in position with those below. There is one exception
FIGURES OF CRYSTALS OF CALCITE.
to this remark, that of the horizontal or basal plane 0, i~ figs.
83 11, 13. The simple rhombohedral forms include:
1. Mhombohedrons, figs. 1 to 6. These forms are included
under six equal planes, like the cube, but these planes sire
4
50
CRYSTALLOGRAPHY.
rhombic ; and instead of having twelve rectang liar edges, thej
have six obtuse edges and six acute.
2. iScalenokedrons, fig. 7. Scaleuohedrons are really double
six-sided pyramids ; but the six equal faces of eaoh extremity
14.
15.
FIGURES OP CRYSTALS OF CALCITE.
of the crystals are scalene triangles, and are arranged in three
pairs ; moreover the pairs above alternate with the pairs below ;
the edges in which the pairs above and below meet — that is the
basal edges — make a zig-zag around the crystal.
3. Hexagonal prisms, jT, fig. 8. These are regular hexagonal
prisms, having angles between their faces of 120°.
A rhombohedron has two of its solid angles made up of three
equal plane angles. When in position the apex of one of these
solid angles is directly over that of the other, as in figs. 1 to 6,
and also in fig. 18, and the line connecting the apices of these
angles (fig. 18) is called the vertical axis. In this position
18.
the rhombohedron has six terminal edges, three above and
three below, and six lateral edges. As these lateral edges
are symmetrically situated around the centre of the crystal, the
three lines connecting the centres of opposite basal edges will
These lines are tha lateral axes of i-he
cross at angles of 60°.
RUOMB01IKDKAL GECTION OF HEXAGONAL Si STEM. 51
rhombohedron, and they are at right angles to the vertical axis.
It is stated on page 45 that rhombohedral forms are, from a
mathematical point of view, hemi/iedral under the hexagonal
system. The rhombohedron, which may be considered a double
three-sided pyramid, is heuiihedral to the double six-sided pyra-
mid. Fig. 19, representing the latter foriif}lias its alternate
faces shaded ; suppressing the faces shaded the form would le
that of fig. 18 ; and suppressing, instead of these, the faces not
shaded, the form would be that of another rhombohedron, dif-
fering only in position. The two are distinguished as plus and
rrdnus rhombohedrons. They are combined in figs. 20, 21,
forms of quartz. Khombohedrons vary greatly in the length of
the vertical axis with reference to the lateral. Figs. 1, 2, 3, and
18 represent crystals with the vertical axis short, and figs. 4, 5,
6 others with a long vertical axis. In the former the terminal
sdges are obtuse and the lateral acute, and the latter have the
terminal edges acute and the lateral obtuse ; the former are
called obtuse rhombohedrons, and the latter acute.
The cube placed on one solid angle, with the diagonal between
it and the opposite solid angle vertical, is, in fact, a rhombohe-
dron intermediate between obtuse and acute rhombohedrons —
the edges that are the terminal in this position, and those thai
are the lateral, being alike rectangular edges. Fig. 3 has nearlj
the form of a cube in this position.
The relation of one series of scalenohedrons to the v\\t tri\to
hedron is illustrated in fig. 22. This figure
represents a rhombohedron with the lateral
edges bevelled. These bevelling planes are
those of a scalenohedron, and the outer lines
of the same figure show the form of that
scalenohedron . which is obtained when the
bevelment is continued to the obliteration
of the rhombohedral planes. Fig. 14 repre-
sents this scalenohedron with the rhombohe-
dral planes much reduced in size. Other
scalenohedrons result when the terminal
edges are bevelled, and still others from
pairs of planes on the angles of a rhombohe-
dron.
The scalenohedron is hemihedral to the
tweVe-sided double pyramid (fig. 23).
Jn the hexagonal system the three verti-
cal axial planes divide the space about the
vertical axis into six sectors (fig. 12, p. 48).
62 CRYSTALLOGRAPHY.
The twelve-sided double pyramid has in each pyramid a pair
of faces for each sector ; that is, six pairs for each pyramid. If
now the three alternate of these pairs, and those in the uppei
pyramid alternate with those of the lower (the shaded in fig. 23),
were enlarged to the obliteration of the rest of the planes, the
/Resulting form would be a scalenohedron — a
solid with three pairs of planes to each pyra-
mid instead of six. Such is the mathematical
relation of the scalenohedron to the twelve-
sided double pyramid. If the faces enlarged
were those not shaded in fig. 23, another
scalenohedron would be obtained which would
be the minus scalenohedron, if the other were
designated the plus.
Fig. 8 shows the relations of a rhombohe-
dron to a hexagonal prism. The planes H
replace three of the terminal edges at each base of the prism,
and those above alternate with those below. The extension
of the planes H to the obliteration of those of the prismatic
planes, I, and that of the basal plane O, would produce the
rhombohedron cf fig. 1. Figs. 9 and 10 represent the same
prism, but with terminations made by the rhombohedron of fig. 2.
By comparing the above figures, and noting that the planes
of similar forms are lettered alike, the combinations in the
figures will be understood. Fig. 1 6 is a combination of the
planes of the fundamental rhombohedron jR, with those of an-
other rhombohedron 4, and of two scalenohedrons I3 and I5.
Fig. 17 contains the planes of the rhombohedron — -j-, with those
of the scalenohedron I8, and those of the prism i. These figures,
and figs. 14, 22, have the fundamental rhombohedron revolved
60° from the position in fig. 1, so that two planes H are in view
above instead of the one in that figure.
2. Lettering of Figures.— Figs. 1 to 6, representing rhomboho-
3rons of the species calcite, are lettered with numerals, excepting fig. 1,
la fig. 1 the letter R stands for the numeral 1, and the numerals on Ihtf
others represent the relative lengths of their vertical axes, the lateral
being equal. In fig. 4 the vertical axis is twice that in fig. 1 ; in fig. 6
thirteen times ; and in fig. 15 the planes lettered 16 are those of a rhom-
bohedron whose vertical axis is sixteen times that of fig. 1. The rhom-
bohedrons of figs. 1, 5, 6, and 15 are plus rhombohedrons; that is, they
are in the same vertical series ; while 2 and 3 are minus rhombohe-
drons, as explained above. The rhombohedron, when its vertical axis
is reduced in Length to zero, becomes the single basal plane lettered 0
in the series. If, on the contrary, the vertical axis of the rbombohe-
ibon is lengthened to infinity, the faces of the rhombohedron become
RHOMBOHEDRAL SECTION OF HEXAGONAL SYSTEM. 53
those of a six-sided prism. This last will be seen from the relations
of the planes It to Ion fig. 8, and from the approximation to a prismatic
form in the planes 16 of fig. 15. For an explanation of the lettering
of other planes on rhombohedral crystals, reference must be made to
the " Text-Book of Mineralogy."
3. Hemihedrism. Tetartohedrism. — Heniihedrism occur*
among rhombohedral forms, similar to that in fig. 13, page 48,
except that the suppressed planes of one pyramid are alternate
with those of the other. One of these is
represanted in fig. 24. The planes C-J are
six in number at each extremity, and are so
situated that they give a spiral aspect to the
crystal. If these planes were only three in
number at each extremity, the alternate
,hree of the six, the form would be tetarto-
hedral to the double six-sided pyramid ;
that is, there would be one-fourth the num-
ber of planes that exist in the double twelve-
sided pyramid, or 6 planes instead of 24.
Such cases of hemihedrism and tetartohe-
diism are common in crystals of quartz, and
when existing, the crystals are said to be
plagihedral, from the Greek for oblique and
face. In some crystals the spiral turns to the
right and in others to the left, and the two kinds are distin-
guished as right-handed and left-handed. There are also tetar-
tohedral forms in which one whole pyramid of a scalenohedron,
or of a rhombohedron, is wanting. For example, in crystals of
tourmaline rhombohedral planes, and sometimes scalenohedral,
may occur at one extremity of the prism and be absent from
the other. This dissimilarity in the two extremities of a crys-
tal of tourmaline is connected with pyro-electric polarity in the
mineral. Three-sided prisms, hemihedral to the hexagonal prism,
are common in some rhombohedral species, as tourmaline.
4. Cleavage. — Cleavage usually takes place parallel to the
faces of a rhombohedron, as in calcite, corundum. Not uniVe-
quently the rhombohedral cleavage is wanting^
and there is highly perfect cleavage parallel to
the basal plane, as in graphite, brucite.
5. Irregularities of Crystals. — Distortions oc-
cur of the same nature with those tinder the
other systems. Some examples are given under
quartz. Some rhombohedral species, as dolomite,
have the opposite faces convex or concave, as in fig. 25.
CRYSTALLOGRAPHY.
Occasional curved crystals occur, as in fig. 26, representing
crystals of quartz, and fig. 2'/ of a crystal of chlorite. The
QUARTZ.
CHLORITE.
feathery crystallizations on windows, called frost, are exampleH
of curved forms under this system.
VII. DISTINGUISHING CHARACTERS OF THE SEVERAL
SYSTEMS OF CRYSTALLIZATION.
1. ISOMETRIC SYSTEM. — (1) There may be symmetrical groups
of 4 and 8 similar planes about the extremities of each cubic
axis ; and of 3 or 6 similar planes about the extremities of each
octahedral axis. (2) Simple holohedral forms may consist of
6 (cube), 8 (octahedron), 12 (dodecahedron), 24 (trapezohedron,
trigonal trisoctahedron, and tetrahexahedron) , and 48 (hexoc-
tahedron) planes.
2. DIMETRIC SYSTEM. — (1) Symmetrical groups of 4 and 8
similar planes occur about the extremities of the vertical
axis only. (2) Prisms occur parallel only to the vertical axis;
and these prisms are either square or eight-sided. (3) The
simple holohedral forms may consist of 2 planes (the bases), of
4 planes (square prisms), of 8 planes (eight-sided prisms and
aquare octahedrons), of 16 planes (double eight-sided pyra-
mids).
3. TRIMETRIC SYSTEM. — ( 1 ) Symmetrical groups of 4 similar
planes may occur about the extremities of Cither axis, but
those of one axis belong equally to the others. (2) The prisms
are rhombic prisms only, and these may occur parallel to either
axis, the horizontal as well as the vertical. (3) Simple holo
TWIN, OE COMPOUND CRYSTALS. 55
hedral forms may consist of 2 planes (the bases, and each pair
of diametral planes), of 4 planes (rhombic prisms in the three
axial directions), and of 8 planes (the rhombic octahedrons).
(4) The forms may be divided into equal halves, symmetrical in
planes, along each of the diametral sections.
4. MONOCLINTC SYSTEM. — (1) No symmetrical groups of
similar planes ever ocour around the extremities of either axis.
(2) The prisms are rhombic prisms, and these can occur paral-
lel only to the vertical axis and the clinodiagonal. (3) The
planes occurring in vertical sections above and below the basal
section, either in front or behind, are all unlike in inclination
to that section, excepting the prismatic planes in the ortho-
diagonal zone ; in other words, true prisms occur in no vertical
section excepting the orthodiagonal. (4) Simple forms consist of
2 planes (the bases, the diametral planes, and hemiorthodomes),
of 4 planes (rhombic prisms in two directions and hemioctahe-
drons). (4) The forms may be divided into equal and similar
halves only along the clinodiagonal section. No interfacial
angle of 90° occurs except between the planes of the clinodiag-
onal zone and the clinopinacoid.
5. TRICLINIO SYSTEM. — In triclinic crystals there are no
groups of similar planes which include more than 2 planes, and
hence the simple forms consist of 2 planes only. The forms
are not divisible into halves having symmetrical planes. There
are no iuterfacial angles of 90°.
(5. HEXAGONAL SYSTEM. — Symmetrical groups of 3, 6, and 12
similar planes may occur about the extremities of the vertical
axis. (2) Prisms occur parallel to the vertical axis, and are
either six or twelve-sided (3 in a hemihedral form) and equi-
lateral. (3) Simple holohedral forms may consist of 2 planes
(the basal), of 6 planes (hexagonal prism), of 12 planes (twelve-
sided prisms and double six-sided pyramids), of 24 planes
(double twelve-sided pyramids). Simple rhombohedral forina
may consist of 2 planes (the basal), of 6 planes (rhombohedrons),
and of 12 planes (scalenonedrons) ,
2. TWIN, OR COMPOUND CBYSTAIS.
Compound crystals consist of two or more single crystals,
united usually parallel to an axial or diagonal section. A few
are represented in the following figures. Fig. 1 represents a
crystal of snow of not uufvequent occurrence. As is evident
56
CRYST ALLOGRAPH Y.
to the eye, it consists either of six crystals meeting in a.point,
or of three crystals crossing one another ; and besides, there are
numerous minute crystals regularly arranged along the rays.
Fig. 2 represents a cross (cruciform) crystal of staurolite, vkic k
1.
5.
is similarly compound, but made up of two intersecting crys-
tals. Fig. 3 is a compound crystal of gypsum, and fig. 4
one of spinel. These will be understood from the following
figures.
Fig. 5 is a simple crystal of gypsum ;
if it be bisected along a b, and the right
half be inverted and applied to the other,
it will form fig. 3, which is therefore a
twin crystal in which one half has a re-
verse position from the other. Fig. 6 is
a simple octahedron ; if it be bisected
along the plane a b c d e, and the upper
half, after being revolved half way
around, be then united to the lower, it
will have the form in fig. 4. Both of these, therefore, are
similar twins, in which one of the two component parts is
reversed in position.
Crystals like figs. 3 and 4 have proceeded from a compound
nucleus in which one of the two molecules was reversed ; and
those like fig. 1, from a nucleus of three (or six) molecules
Compound crystals of the kinds above described, thus differ
from simple crystals in having been formed from a nucleuK
of two or more united molecules, instead of from a simple
nucleus.
Compound crystals _tre generally distinguished by their -re-en-
tering angles, and often also by the meeting of striae at an angle
along a line on a surface of a crystal, the line indicating the
plane of junction of the two crystals.
Compound crystals are called twolings, threelings, fourlings,
according as they consist of two, three, or four united crystals.
TWIN, OR COMPOUND CRYSTALS.
57
Fig. 1 represents a threeling, and 2, 3, and 4, twolings. In 3
and 4 the combined crystals are simply in contact along the
plane of junction ; in 2 they cross one another; the former are
called coidact-twins and the latter penetration-twins.
Besides the above, there are also geniculated crystals, as in
tlj2 annexed figure of a crystal of rutile. The bending has here
*tke«u place at equal distances from the centre
of the crystal, and it must therefore have been
subsequent in time to the commencement of
the crystal. jLhe prism began from a simple
molecule ; but after attaining a certain length
an abrupt change of direction took place. The
angle of geniculation is constant in the same
mineral species, for the same reason that the
interfacial angles of planes are fixed ; and it is such that a cross
section directly through the geniculation is parallel to the posi-
tion of a common secondary plane. In the figure given the
plane of geniculation is parallel to one of the terminal edges.
In rutile the geniculated crystals sometimes repeat the bendings
at each end until the extremities meet to form a wheel-like
twin.
In some species, as albite, the reversion of position on which
this kind of twin depends, takes place at so short intervals that
the crystal consists of parallel plates,
8. 9. each plate often less than a twen-
tieth of an inch in thickness. A sec-
tion of such a crystal, made trans-
verse to the plate, is given in tig. 8 ;
without the twinning the section
would have been as in fig. 9. Tiie
plates, as the figure shows, make with
one another at their edges a re-enter-
ing angle (in albite an angle of 172°
48'), and hence a plane of the albite
crystal at right angles to the twin-
ning direction, is covered with a series of ridges and depressions
which are so minute as to be only fine striations, sometimes
requiring a magnifying power to distinguish. Such striationa
in -ilbite are therefore an indication of the compound struc-
ture.
This kind of twinning is owing to successive changes of
polarity in the molecules as the enlargement of the crystal
went forward. It occurs in all the tricliiiic feldspars, and is a
means of distinguishing them from orthoclase.
58
CRYSTALLOGRAPHY.
In some twin crystals the two component parts of the crystal
are not united by an even plane, but run
into one another with great irregularity.
Cases of this kind occur in the species of
quartz in twins made up of the forms M
and —R (or —1). In fig. 10 the shaded
parts of the pyramidal planes are of the
form — 1, and the non-shaded parts of
R. Each of the faces is made up partly
of R and partly of —1. The limits of
the two are easily seen on holding the
crystal up to the light, since the — 1
portion is less well polished than the
other. In this crystal, as in other crys-
tals of quartz, the striatioiis of planes *
are owing to oscillations between pyram-
idal and prismatic planes while the for
mation of the latter was in progress.
3. CRYSTALLINE AGGREGATES.
The crystalline aggregates here included are the simple, not
the mixed ; that is, they are those consisting of crystalline in-
dividual? of a single species.
The crystalline individuals may be (1) distinct crystals ; (2)
fibres or columns ; (3) scales or lamellae ; or (4) grains, either
cleavable or not so.
1. Consisting of distinct crystals. — The distinct crystal may
be either long or short prismatic, stout or slender to acicular
(needle-like), and capillary (hair-like) ; or they may have any
other forms of crystals. They may be aggregated (a) in lines ;
(b) promiscuously with open spaces ; (c) over broad surfaces ;
(d) about centres. The various kinds of aggregates thus made
ure :
a. Filiform. — Thread-like lines of crystals, the crystals often
not well defined.
b. Dendritic. — Arborescent slender spreading branches, some-
what plant-like, made up of more or less distinct crystals, as in
the frost on windows, and in arborescent forms of native cop-
per, silver, gold, etc.
Fig. 1 1 represents, much magnified an arborescent form of
magnetite occurring in mica at Pennsbury, in Pennsylvania.
A rborescent delineations over surfaces of rock are Msually called
CRYSTALLINE AGGREGATES.
59
it.
dtndrites. They have been formed by crystallization from a
solution of mineral matter which has entered by some crack and
spread between the layers of
the rock. They are often
black, and consist of oxide
of manganese ; others, of a
brownish color, are made of
limonite ; others, of a red-
dish black or black color, of
hematite. Moss-like forms
also occur, as in moss agate.
c. Reticulated. — Slender
prismatic crystals promiscu-
ously crossing, with open
spacings.
d. Divergent. — Free crys-
tals radiating from a central
point.
e. Drusy. — A surface is drusy when made up of the extremi-
ties of small crystals.
2. Consisting of columnar individuals.
a. Columnar, when the columnar individuals are stout.
b. Fibrous, when they are slender.
c. Parallel fibres, when the fibres are parallel.
d. Radiated, when the columns or fibres radiate from
centres.
e. Stellated, when the radiations from a centre are equal
around, so as to make star-like or circularly-radiated groups.
f. Globular, when the radiated individuals make globular or
hemispherical forms, as in wavellite.
y. Botryoidal) when the globular forms are in groups, a lit-
tle like a bunch of grapes. The word is from the Greek for a
bunch of grapes.
k. Mammillary, having a surface made up of low and broad
prominences. The term is from the Latin mammilla, a little
teat.
L Coralloidal, when in open-spaced groupings of slender
stems, looking like a delicate coral. A result of successive ad-
ditions at the extremity of a prominence, lengthening it into
cylinders, the stems generally having a faintly radiated struc-
ture.
Specimens of all these varieties of columnar structure, except-
ing the last, often have a druay surface, the fibres or column!
ending in projecting crystals.
60 CRYSTALLOGRAPHY.
3. Consisting of scales or lamellae.
a. Plumose, having a divergent arrangement of scales, aa
seen on a surface of fracture; e. g., plumose mica.
b. Lamellar, tabular ', consisting of flat lamellar crystalline in-
dividuals, superimposed and adhering.
c. Micaceous, having a thin fissile character, due to the aggi»
gation of scales of a mineral which, like mica, has eminuai
cleavage.
d. Septate, consisting of openly-spaced intersecting tabular
individuals ; also divided into polygonal portions by reticulat-
ing veins or plates. A septarium is a concretion, usually flat-
tened spheroidal in shape, the solid interior of which is inter-
sected by partitions ; these partitions are the fillings of cracks
in the interior that were due to contraction on drying. When
the surface of such septate concretions has been worn off, they
often have the appearance of a turtle's back, and are sometimes
taken for petrified turtles.
4. Consisting of grains. Granular structure. A massive
mineral may be coarsely granular or finely granular, as in
varieties of marble, granular quartz, etc. It is termed saccha-
roidal when evenly granular, like loaf sugar. It may also be
cryptocrystalline, that is, having no distinct grains that can.
be detected by the unaided eye, as in flint. The term crypto-
crystalline is from the Greek for concealed crystalline. Aphani-
tic, from the Greek for invisible, has the same signification. The
term ceroid is applied when this texture is connected with a
waxy lustre, as in some common opal.
Under this section occur also globular, botryoidal, and inam-
millary forms, as a result of concretionary action in which no
distinct columnar interior structure is produced. They are
called pisolitic when in masses consisting of grains as large as
peas (from the Latin pisum, a pea), and oolitic when the grains
are not larger than the roe of a fish, from the Greek for egg.
5. Forms depending on mode of deposition. — Besides the
above, there are the following varieties which have ccme from
mode of deposition :
a. Stalactitic, having the form of a cylinder, or cone, haLg-
ing from the roofs of cavities or caves. The term stalactite is
usually restricted to the cylinders of carbonate of calci im hanging
from the roofs of caverns ; but other minerals are said to have
a stalactitic form when resembling these in their general shape
and origin. Chalcedony and brown iron ore are often stalacti-
tic. Interiorly the structure may be either granular, radiatelj
fibvo'ls, or concentric.
CRYSTALLINE AGGREGATES. 61
6, Concentric. — When consisting of lamellae, lapping one
ovei another around a centre, a result of successive concretion-
ary aggregations, as in many concretionary forms, most pisolite,
part of oolite, some stalactites, etc.
c. Stratified, consisting of layers, as a result of deposition :
e. g ; sc me travertine, or tufa.
d. Jiznded / color-stratified. Like stratified in origin, but
the layers usually indicated only by variations in color ; the band-
ing is shown in a transverse section : e. g., agate, much stalag-
mite, riband jasper.
e. Geodes. — When a cavity has been lined by the deposition
of mineral matter, but not wholly filled, the enclosing mineral
is called a geode. The mineral is often banded, owing to the
successive depositions of the material, and frequently has its
inner surface set with crystals. Agates are often slices or frag-
ments of geodes.
6. Forms derived from the crystals of other minerals. Pseu-
domorphs. — Crystalline aggregates, especially the granular,
sometimes have forms derived from the crystals of other
minerals either
(1) Because a result of cotemporaneous removal and substi*
tution ; or
(2) Because a result of the alteration of such crystals ; or
(3) Because filling spac.es that had been left unoccupied in
consequence of previous removal.
For example. Crystals occur having the forms of calcite
(calcium carbonate, or " carbonate of lime "), but consisting of
quartz or silica. They were made from calcite crystals by the
action of some solution containing silica, the solution dissolving
away the calcite and depositing at the same time silica or quartz.
Specimens occur showing all stages in the change from the ear-
liest in which the calcite is thinly coated with quartz, to the
last, in which it is all quartz. Such crystals are pseudoinorphs
of quartz after calcite. Siliceous fossil shells and corals are
similar pseudomorphs after catcite, since shells and corals con-
sist chiefly of calcite. Other quartz pseudomorphs have the
form of fluorite, barite, etc.
Again, the forms of calcite occur with the constitution of
limonite, a hydrous iron oxide. In such a case the iron oxide
was in the solution that corroded and dissolved away the
calcite.
Again, the forms of calcite occur with the constitution of
serpentine, a hydrous magnesium silicate ; and in this ctiso the
ingredients of the serpentine silicate were present when the
62 CRYSTALLOGRAPHY.
calcite was dissolved away by the corrosive solvent, and took
its place as the calcite particles were removed.
In all the above cases the pseudomorphs were made by simple
removal and cotemporaneous substitution.
Again, crystals of the form of chrysolite, a magnesium sili
ca^.e, occur, altered to serpentine, a hydrous magnesium silicate.
II 3re the pseudomorph was made by a process of alteration,
part of the ingredients remaining, and only water added.
Again, crystals of siderite (spathic iron or iron carbonate)
occur changed to limoriite, a hydrous iron oxide. Here there
was an oxidation of the iron of the carbonate, and the addition
of water. This is another example of pseudomorphs by altera-
tion. Similarly orthoclase changes to kaolin, and kaolin has
the form at times of orthoclase crystals.
Again, crystals of the form of those of common salt occur
consisting of clay or of calcite, which were made by deposition
in a cavity left by the dissolving away of an imbedded crystal
of salt. These are pseudomorphs by deposition.
Again, crystals of aragonite, prismatic calcium carbonate,
occur consisting of calcite or rhombohedral calcium carbon-
ate ; and here there is a change in crystallization without any
change of chemical composition.
7. Fracture. — Kinds of fracture in these crystalline aggre-
gates depend on the size and form of the particles, their cohe-
sion, and to some extent their having cleavage or not.
Among granular varieties, the influence of cleavage is in all
cases very small, and in the finest almost or quite nothing. The
term hackly is used for the surface of fracture of a metal, when
the grains are coarse, hard, and' cleavable, so as to be sharp
and jagged to the touch ; even, for any surface of fracture when
it is nearly or quite flat, or not at all conchoidal ; conchoidal,
when the mineral, owing to its extremely fine or cryptocrystal-
line texture and hardness, breaks with shallow concavities and
convexities over the surface, as in the case of flint. The word
conchoidal is from the Latin concha, a shell. These kinds of
fracture are not of much importance in mineralogy, siuce they
distinguish varieties of minerals only, and not species.
HAKDNESS — TENACITY — SPECIFIC GRAVITY. 03
2. PHYSICAL PROPERTIES OF
MINERALS.
THE physical properties referred co in the description and
determination of minerals are here treated under the following
heads: (1) Hardness; (2) Tenacity; (3) Specific Gravity;
(4) Refraction, Polarization ; (5) Diaphaneity, Color, Lustre;
(6) Electricity and Magnetism ; (7) Taste and Odor,
1. HARDNE&S.
The comparative hardness of minerals is easily ascertained,
and should be the first character attended to by the student in
examining a specimen. It is only necessary to draw a lile
across the specimen, or to make trials of scratching one wi.th
another. As standards of comparison the following minerals
have been selected, increasing gradually in hardness from talc,
which is very soft and easily cut with a knife, to the diamond.
This table, called the scale of hardness, is as follows :
1, talc, common foliated variety; 2, rock salt j 3, calcfct
transparent variety ; 4, Jluorite, crystallized variety; 5, apatite,
transparent crystal ; 6, ort/ioclase, cleavable variety ; 7, quartz,
transparent variety ; 8, topaz, transparent crystal ; 9, sapphire^
cleavable variety; 10, diamond.
If, on drawing a file across a mineral, it is impressed as easily
as Jluorite, the hardness is said to be 4 ; if as easily as ortho-
close, the hardness is said to be 6 ; if more easily than ortho-
clase, but with more difficulty than apatite, its hardness is de-
scribed as 5J or 5 '5.
The file should be run across the mineral three or four times,
and care should be taken to make the trial on angles equally
blunt, and on parts of the specimen not altered by exposure.
Trials should also be made by scratching the specimen under
examination with the minerals in the above scale, since some-
times, owing to a loose aggregation of particles, the file wears
tlown the specimen rapidly, although the particles are very
haru.
In crystals the hardness is sometimes appreciably different in
degree in the direction of different axes. In crystals of mic*
64 PHYSICAL PROPERTIES OF MINERALS
the hardness is less on the basal plane of the prism, that is, on
the cleavage surface, than it is on the sides of the prism. On
the contrary, the terminatitn of a crystal of cyanite is harder
than the lateral planes The degree of hardness in different
directions may be obtained with great accuracy by means of an
instrument called a sclerometer.
2. TENACITY.
The following rather indefinite terms are used with reference
to the qualities of tenacity, malleability, and flexibility in min-
erals :
1. ^Brittle. — When a mineral breaks easily, or when parts of
the mineral separate in powder on attempting to cut it.
2. Malleable. — When slices may be cut off, and these slices
will flatten out under the hammer, as in native gold, silver,
copper.
3. Sectile. — When thin slices maybe cut off with a knife.
All malleable minerals are sectile. Argentite and cerargyrite
are examples of sectile ores of silver. The former cuts nearly
like lead and the latter nearly like wax, which it resembles.
Minerals are imperfectly sectile when the pieces cut off pul-
verize easily under a hammer, or barely hold together, as sele-
nite.
4. Flexible. — When the mineral will bend, and remain bent
after the bending force is removed. Example, talc.
5. Elastic. — When, after being bent, it will spring back to
its original position. Example, mica.
A liquid is said to be viscous when on pouring it the drops
lengthen and appear ropy. Example, petroleum.
3. SPECIFIC GRAVITY.
The specific gravity of a mineral is its weight compared with
that of some substance taken as a standard. For solids ar.d
liquids distilled water, at 60° F., is the standard ordinarily
used ; and if a mineral weighs twice as much as water, its spe-
cific gravity is "2 ; if three times it is three. It is then necessary
to compare the weight of the mineral with the weight of an
equal bulk of water. The process is as follows :
First weigh a fragment of the mineral in the ordinary way,
SPECIFIC GRAVITY.
65
with a delicate balance j next suspend the mineral by a hair, or
fibre of silk, or a fine platinum wire, to one of the scales, im-
merse it thus suspended in a glass of distilled water (keeping
the scales clear of the water) and weigh it again; subtract the
second weight from the first, to ascertain the loss by immersion,
and divide the first by the difference obtained ; the result is the
specific gravity. The loss by immersion is equal to the weight
of an equal volume of water. The trial should be made on a
small fragment ; two to five grains are best. The specimen
should be free from impurities and from pores or air-bubbles.
For exact results the temperature of the water should be noted,
and an allowance be made for any variation from the height of
thirty iuches in the barometer. The observation is usually
made with the water at a temperature of 60° F. ; 39° '5 F., the
temperature of the maximum density of water, is preferable.
The accompanying figure represents the
spiral balance of Jolly, by which the weight
is measured by the torsion of a spiral brass
wire. On the side of the upright (A) which
faces the spiral wire, there is a graduated
mirror, and the readings which give the
weight of the mineral in and out of water are
made by means of an index (at m) connected
with the spiral wire ; and its exact height,
with reference to the graduation, is obtained
by noting the coincidence between it and
i:s image as reflected by the graduated mir-
ror, c and d are the pans in which the piece
of mineral is placed, first in c, the one out
of the water, and then in d, that in the
water.
Another process, and one available for
vorous as well as compact minerals, is per-
.ormed with a light glass bottle, capable of
holding exactly a thousand grains (or any
known weight) of distilled water. The
specimen should be reduced to a coarse pow-
der, Pour out a few drops of water from
the bottle and weigh it ; then add the pow-
dered mineral till the water is again to the brim, and reweigh
it ; the difference in the two weights, divided by the loss oi
water poured out, is the specific gravity sought. The weight
of the glass bottle itself is here supposed to be balanced by an
squivalent weight in the other scale.
5
771
66 PHYSICAL PROPERTIES OF MINERALS.
4. REFRACTION AND POLARIZATION.
Minerals differ widely in their refracting and polarizing
properties, and hence these properties are a convenient means
of distinguishing species. The explanations of the subject, and
the methods of careful experimenting, will be found in treatises
on optics, and also at considerable length, and with minute
directions as to the use of instruments, in the Text-Book of
Mineralogy. Only a few of the simpler facts required for the
ordinary purposes of the mineralogist are here mentioned.
The character of the refraction varies according to the sys-
tem of crystallization.
A. In isometric crystals there is simple refraction alike in
all directions, and no polarization.
B= In dimetric and hexagonal crystals the vertical axis, or
axis of symmetry, is the direction of the optic axis ; in all
directions except this a transmitted ray of light is doubly re-
fracted. Such crystals are optically uniaxial.
C. In trimetric, monoclinic, and triclinic crystals, which
have the three axes unequal, there are two directions of no
double-refraction. Such crystals are optically biaxial.
1. Isometric System. — In the isometric system there is no
reference whatever in the refraction to crystalline structure,
and in this respect substances thus crystallizing are like water.
There is only simple refraction. The index of refraction is ob-
tained by dividing the sine of the angle of incidence of a ray of
light by the sine of its angle of refraction. Thus if a ray of
light strike the surface of a transparent plate of the mineral at
an angle of 40° from the perpendicular, and then passes through
the plate at an angle of 30° from the perpendicular, owing to
the refraction, the sine of 40° divided by the sine of 30° will
be the index of refraction. Now the index of refraction of air
being made the unit, that of water is 1 '335 ; of fluorite, 1'434 ;
of rock salt, 1-557; of spinel, 1*764; of garnet, 1-815; of
blende, 2-260; of diamond, 2'439.
2. Crystals Uniaxial in Polarization. — A transparent cleav-
age plate from a crystal of calcite shows what is called double
refraction. Placed over a line drawn on any surface, two
parallel lines are seen, one produced by the ordinary ray, and
the other by the extraordinary ray. Both rays are polarized,
and in planes at right angles to each other. Prisms, called
Nicol prisms, made from transparent calcite (Iceland Spar),
are employed for obtaining polarized light. Transparent
REFRACTION AND POLARIZATION.
67
plates of tourmaline, cut from a crystal parallel to the vertical
axis, also are used for this purpose. Another method of ob-
taining it is by reflection — light, when reflected at a certain
angle from a polished surface, being polarized ; the angle of
reflection differs for different substances.
The above figure represents a simple polariscope made with
two tourmaline plates, which is convenient for many ordinary
observations. The best instruments for the purpose are made
with Nicol prisms, and are adapted to microscopic work. The
prisms, placed within the tube of the instrument, one of them
below the stage, are arranged so as to admit of revolution ; and
the stage also has a graduated circle and revolves. The com-
pound microscope also is often converted into a polariscope by
Nicol prisms arranged for this purpose.
When a crystal with one axis of polarization, as, for example,
calcite, is examined by means of a ray of polarized light passed in
the direction of the vertical axis, concentric circular rings are
seen, having the colors of the spectrum intersected by either a
black or a white cross, as in figs. 1, 2. To make the observa-
3.
tion it is necessary that the calcite crystal should have its ex-
tremities polished at right angles to the vertical axis. If a
tourmaline plate be placed against or near one of its polished
68 PHYSICAL PROPERTIES OF MINERALS.
faces, and a similar tourmaline plate in front of the opposite
face, the colored rings will be seen on looking through ; and by
revolving one of the tourmaline plates a change will be observed
at each 90° of revolution, in the colors of the rings, and in the
variations in appearance of the cross from black to white, and
the reverse. The fact in any case that the rings of color are
perfect circles, and the black cross a symmetrical one, is proof
that the crystal is either of the dimetric or hexagonal system.
But sometimes very exact observation is necessary to deter-
mine the truth.
3. Crystals Biaxial in Polarization. — Biaxial crystals are
those having two optic axes, and the angle between them is
called the axial angle.
When a section of such a crystal, at right angles to the line
bisecting the acute axial angle, is viewed in converging polar-
ized light, the two axes are seen with a series of elliptical col-
ored rings surrounding each. If the section is so placed that
the line joining the axes coincides with the vibration-plane of
either Nicol prism, or tourmaline plate, an unsymmetrical
0.
GLAUBER SALT. PHLOGOPITE, ANTWERP, N. Y.
black cross is also seen, as in fig. 4; if it makes an angle of 45°
with this, two curved black bars are observed, as in fig. 5. In
either case the colors are reversed, and the black changed to
white as one of the Nicols is revolved. Fig. 6 shows the
axial figure for phlogopite (in the second position mentioned
above) where the axial angle is very small. The rings are loss
numerous and farther apart the thinner the section that is
employed in making the observations.
In muscovite (common mica) the angle between the axes is
50° to 70°, and, if the tourmaline tongs are employed, the two
REFRACTION AND POLARIZATION. C9
series of rings are visible only when viewed in directions very
oblique to one another.
4. Circular Polarization in Uniaxial Crystals. — It is stated
on page 53 that quartz crystals have often a left handed and a
right-handed arrangement of planes. This is connected with a
right-handed and left-handed molecular structure in crystals of
this species. When a plate cut at right angles to the axis is ex-
amined by the polarized light, instead of presenting a black
cross, the centre of the rings appears brightly colored, and if the
polarizer is revolved, this color changes from blue to yellow,
thnn red, right-handed crystals requiring revolution to the
right and left-handed to the left for this succession. This prop-
erty seems to distinguish the smallest grains of quartz, and may
be easily observed in a good polariscope.
5. Anomalies in Polarization. — There are some isometric
crystals which have the property of polarization. Boracite is
one example ; and it is explained by the presence of another
mineral in minute particles, distributed regularly through the
crystals. Perofskite is another case ; and it has suggested a
doubt as to its being isometric. Octahedrons of alum some-
times have polarization, and it has
been shown to be due to the crystals
being made up of thin plates — light,
when transmitted through a pile of
such plates, becoming polarized. Dia-
monds are sometimes vmiaxial.
Aualcite was long since described
by Sir David Brewster as an example
of polarization under the isometric
system. Its trapezohedrons exhibit
a symmetrical arrangement of lines of
prismatic colors and alternating dark
lines with cross-bands, as imperfectly
shown in the annexed figure. Trapezohedrons of leucite are
somewhat similar in their polarizing character. The effect in
both species is connected with twinning ; but, besides, accord-
ing to recent observers, the crystallization is dimelric. One
writer makes crystals of analcite to be trimetric twins, analogous
those of phillipsite. Twinning in crystals is a very common
source of irregularities. A regular twinning of laminae of bi-
axial crystals around a centre may give a uniaxial character to
the twin. Apophyllite is a dimetric species, showing peculiari-
ties in its colors arising from the different action of the mineral
in light of different colors.
70 PHYSICAL PROPERTIES OF MENEBAL8.
5. DIAPHANEITY, LUSTRE, COLOR.
1. DIAPHANEITY.
Diaphaneity is the property which many objects possess of
transmitting light ; or, in other words, of permitting more or
less light to pass through them. This property is often called
transparency, but transparency is properly one of the degrees
cf diaphaneity. The following terms are used to express the
different degrees of this property :
Transparent — a mineral is said to be transparent when the
outlines of objects, viewed through it, are distinct. Example,
glass, crystals of quartz.
Subtransparent; or semitransparent — when objects are seen
but their outlines are indistinct.
Translucent — when light is transmitted, but objects are not
seen. Loaf sugar is a good example j also Carrara marble.
Subtranslucent — when merely the edges transmit light faintly.
When no light is transmitted the mineral is described as
opaque.
2. LUSTRE.
The lustre of minerals depends on the nature of their surfaces,
which causes more or less light to be reflected. There are dif-
ferent degrees of intensity of lustre, and also different kinds of
lustre.
a. The kinds of lustre are six, and are named from some
familiar object or class of objects.
1. Metallic — the usual lustre of metals. Imperfect metallic
lustre is expressed by the term submetallic.
2. Vitreous — the lustre of broken glass. An imperfect
vitreous lustre is termed subvitreous. Both the vitreous and
sub vitreous lustres are common. Quartz possesses the former
in an eminent degree ; calcareous spar often the latter. This
kind of lustre may be exhibited by minerals of any color.
3. Hesinous — lustre of the yellow resins. Example, some
opal, zinc blende.
4. Pearly — like pearl. Example, talc, native magnesia, gtil-
bite, etc. When united with submetallic lustre the term
metallic-pearly is applied.
ii. 8Uky — like silk; it is the result of a. fibrous structure.
DIAPHANEITY— LU8TKE COLOK. 71
Example, fibrous calcite, fibrous gypsum, and many fibrous
minerals, more especially those which in other forms have a
pearly luwtre.
6. Adamantine — the lustre of the diamond. When sub-
metallic, it is termed metallic adamantine. Example, some
varieties of white lead ore or cerussite.
b. The degrees of intensity are denominated as follows:
1. Splendent — when the surface reflects light with great bril-
liancy and gives well-defined images. Example, Elba hematite,
tin ore, some specimens of quartz and pyrite.
2. Shining — when an image is produced, but not a well-de-
fined image. Example, calcite, celestite.
3. Glistening — when there is a general reflection from the
surface, but no image. Example, talc.
4. Glimmering — when the reflection is very imperfect, and
apparently from points scattered over the surface. Example,
flint, chalcedony.
A mineral is said to be dull when there is a total absence of
lustre. Example, chalk.
3. COLOR.
1. Kinds of Color. — In distinguishing minerals, both the ex
ternal color and the color of a surface that has been rubbed 01
scratched, are observed. The latter is called the 'streak, and the
powder abraded, the streak-powder.
The colors are either metallic or unmetallic.
The metallic a^ named after some familiar metal, as copper-
red, bronze-yeilow, brass-yellow, gold-yellow, steel-gray, lead-
gray, iron-gray.
The unmetallic colors used in characterizing minerals are
various shades of white, gray, black, blue, green, yellow, red and
brown.
There are thus snow-white, reddish-white, greenish-white,
milk-white, yellowish-white.
Bluish-gray, smoke-gray, greenish-gray, pearl-gray, ash-gray.
Velvet-black, greenish-black, bluish-black, grayish-black.
Azure-blue, violet-blue, sky-blue, indigo-blue.
Emerald-green, olive-green, oil-green, grass-green, apple-green,
bUckish-green, pistachio-green (yellowish).
Sulphur-yellow, straw-yellow, wax-yellow, ochre-yellow,
honey-yellow, orange-yellow.
Scarlet-red, blood-red, flesh red, brick-red, hyaiinth-red, rose-
red, cherry-red.
72 PHYSICAL PROPERTIES OF MINERALS.
Hair-brown, reddish-brown, chestnut-brown, yellowish-brown,
pinchbeck-brown, wood-brown.
A play of colors — this expression is used when several pris-
maiic colors appear in rapid succession on turning the mineral.
The diamond is a striking example ; also precious opal.
Change of colors — when the colors change slowly on turning
in different positions, as in labradorite.
Opalescence — when there is a milky or penrly reflection
from the interior of a specimen, as in some opals, and in cat's
eye.
Iridescence — when prismatic colors are seen within a crystal,
it is the effect of fracture, and is common in quartz.
Tarnish — when the surface colors differ from the interior ;
it is the result of exposure. The tarnish is described as irised
when it has the hues of the rainbow.
2. Dichroism, Trichroism. — Some crystals, under each of the
systems excepting the isometric, have the property of present-
ing different colors by transmitted light in different directions.
The property is called dichroism when these colors are seen in
two directions, and trichroism (or pleochroism) if seen in three
directions. The colors are always the same in the direction
of equal axes and often unlike in the direction of- unequal
axes. As dimetric and hexagonal crystals have the lateral axes
equal they can present different colors only in two directions,
the vertical and lateral; while all crystals that are optically
biaxial may be trichroic.
The mineral iolite is a noted example, and received the name
dichroite on account of this property. Transparent colored
crystals of tourmaline, topaz, epidote, mica, diaspore, and many
other species exhibit it. Tourmaline crystals, when transpar-
ent or translucent transverse to the prism, are opaque in the
direction of the vertical axis ; and so also are thick crystals of
mica. Colored varieties of hornblende are dichroic, while
those of the related mineral, pyroxene, are not so.
This quality is best observed by means of polarized light. On
examining a mineral with a tourmaline plate, or Nicol prism, the
two colors in a dichroic mineral are successively seen as the
tourmaline or Nicol is revolved ; and if there is no dichroism
there is no change of color. A small instrument, containing a
prism of calcite, has been constructed for showing the dichro-
ism, called the dichroscope. On looking through it at a di-
chroic crystal, the aperture against the crystal appears double,
owing to the double refraction of the calcite, one image being
made by the ordinary ray and the other by the extraordinary
ELECTBICITY AND MAGNETISM. 73
ray ; and the two colors are seen side by side, at intervals of
90° in the revolution of the mineral.
For opaque minerals it is necessary to make a thin transparent
section of the mineral and examine it with a polari scope, or with
a microscope arrange^ ''. ict as one by the addition of one Nicol
prism. The opaque /-nblende of rocks is thus distinguished
from pyroxene, and so in other cases.
3. Asterism. — Some crystals, especially the hexagonal, when
viewed in the direction of the vertical axis, present peculiar re-
flections in six radial directions. This arises either 'from pecu-
liarities of texture along the axial portions, or from some im-
purities. A remarkable example of it is that of the asteriated
sapphire, and the quality adds much to its value as a gem.
The six rays are sometimes alternately shorter, indicating the
rhombohedral character of the crystal.
4. Phosphorescence. — Several minerals give out light either
by friction or when gently heated. This property of emitting
light is called phosphorescence.
Two pieces of white sugar struck against one another give a
feeble light, which may be seen in a dark place. The same
effect is obtained on striking together fragments of quartz, and
even the passing of a feather rapidly over some specimens or
zinc blende is sufficient to elicit light.
Fluorite is the most convenient mineral for showing phos
phorescence by heat. On powdering it, and throwing it on a
plate of metal heated nearly to redness, the whole takes on a
bright glow. In some varieties the light is emerald green ; in
others, purple, rose, or orange. A massive fluor, from Hun
tington, Connecticut, shows beautifully the emerald green phos-
phorescence.
Some kinds of white marble, treated in the same way, gU ^
out a bright yellow light.
After being heated for a while the mineral loses its phoa-
phorescence ; but a few electric shocks will, in many cases, to
some degree restore it again.
6. ELECTRICITY, AND MAGNETISM.
ELECTRICITY. — Many minerals become electrified on being
nibbed, so that they will attract cotton and other light sub-
stances ; and when electrified some exhibit positive and others
negative electricity, when brought near a delicately suspended
magnetic needle. The diamond, whether polished or not, ai-
74 PHYSICAL PROPERTIES OF MINERALS.
ways exhibits positive electricity, while other gems become
negatively electric in the rough state, and positively only in the
polished state. Some minerals, thus electrified, retain the powoi
of electric attraction for many hours, as topaz, while others lose
it in a few minutes.
Many minerals become electric when heated, and such speciea
are said to be pyro~electric, from the Greek put, fire, and
electric.
A prism of tourmaline, on being heated, becomes polar ; ono
extremity will be attracted, the other repelled, by a pole of a
strong magnet. The prisms of tourmaline have different second-
ary planes at the two extremities.
Several other minerals have this peculiar electric property,
especially boracite and topaz, which, like tourmaline, are hemi-
hedral in their modifications. Boracite crystallizes in cubes,
with only the alternate solid angles similarly replaced (figs. 39,
40, page 25). Each solid angle, on heating the crystals, be-
comes an electric pole ; the angles diagonally opposite are dif-
ferently modified and have opposite polarity. Pyroelectricity
has been observed also in crystals that are not hemihedral, and
in many mineral species. In some cases the number of poles is
more than two. In prelmite crystals a large series occur dis-
tributed over the surface.
MAGNETISM. — The name Lodestone is given to those specimens
of an ore of iron, called magnetite which have the power of at-
traction like a magnet ; it is common in many beds of magnetite.
When mounted like a horse-shoe magnet, a good lodestone will
lift a weight of many pounds. This is the only mineral that
has decided magnetic attraction. But several ores containing
iron are attracted by the magnet, or, when brought near a
magnetic needle, will cause it to vibrate; and moreover, the
metals nickel, cobalt, manganese, palladium, platinum and os-
mium, have been found to be slightly magnetic.
Many minerals become attractable by the magnet after being
heated that are not so before heating. This arises from a
change of part or all of the iron to the magnetic oxide.
7. TASTE AND ODOR.
Taste belongs only to the soluble minerals ; the kinds are—
1. Astringent — the taste of vitriol.
2. Sweetish-astringent — the taste of alum.
3. Saline — taste of common salt.
TASTE AND ODOB. 75
4. Alkaline — taste of soda.
5. Cooling — taste of saltpetre.
6. Bitter — taste of epsom salts.
7. Sour — taste of sulphuric acid.
Odor is not given off by minerals in the «ry, unchanged
state, except in the case of a few gases and soluble minerals.
By friction, moistening with the breath, the action of acids and
the blowpipe, odors are sometimes obtained, which are thus
designated :
1. Alliaceous — the odor of garlic. It is the odor of burning
arsenic, and is obtained by friction, and more distinctly by
means of the blowpipe, from several arsenical ores.
2. Horse-radish odor — the odor of decaying horse-radish. It
is the odor of burning selenium, and is strongly perceived when
ores of this metal are heated before the blowpipe.
3. Sulphureous — odor of burning sulphur. Friction will
elicit this odor from pyrites, and heat from many sulphides.
4. Fetid — the odor of rotten eggs or sulphuretted hydrogen.
It is elicited by friction from some varieties of quartz and lime-
stone.
5. Argillaceous — the odor of moistened clay. It is giren oflf
by serpentine and some allied minerals when breathed upon.
Othf r?, as pyrargillite, afford it when heated.
70
CHEMICAL PROPERTIES OF MINERALS.
8. CHEMICAL PROPERTIES
MINERALS.
OP
THE chemical properties of minerals are of two kinds. (1)
Those of the chemical composition of minerals, (2) those de-
pending on their chemical reactions, with or without fluxes, in-
cluding results obtained by means of the blowpipe.
1. CHEMICAL COMPOSITION.
All the elements made known by chemistry are found in
minerals, for the mineral kingdom is the source of whatever
living beings — plants and animals— contain or use. A list of
these elements, as at present made out, is contained in the fol-
lowing table, together with the symbol for each used in stating
the composition of substances. These symbols are abbreviations
of the Latin names for the elements. A few of these Latin
names differ much from the English, as follows :
Stibium Sb = Antimony
Cuprum Cu = Copper
Ferrum Fe =r Iron
Plumbum Pb =z Lead
Hydrargyrum Hg = Mercury
Kalium
Argentum
Natrium
Stannura
K = Potassium
Ag = Silver
Na = Sodium
Sn = Tin
Wolframium W = Tungsten
TABLE OF THE ELEMENTS.
Aluminum
Antimony
Arsenic
Barium
Bismuth
Boron
Bromine
Cadmium
Ceesium
Calcium
Carbon
Cerium
Chlorine
Chromium
Cobalt
Al
27-4
Sb
120
As
75
Ba
137
Bi
210
B
11
Br
80
Cd
112
Cs
133
Ca
40
C
12
Ce
138
Cl
35-5
Cr
522
Co
58-8
Columbium (Niobium) Cb (Nb) 94
Copper Cu 63 '4
Didymium D 144 '8
Erbium E 168 -9
Fluorine F 19
Gallium Ga 68 ?
Glucinum (Beryllium) G (Be) 9 '4
Gold Au 197
Hydrogen H 1
Indium In 113 '4
Iodine I 127
Jridium Ir 198
Iron Fe 56
Lanthanum La 139
Lead Pb 207
CHEMICAL COMPOSITION OF MINERALS.
77
Li
7
Silver
Mg
24
Silicon
Mn
55
Sodium
Kg
200
Strontium
Mo
96
Sulphur
Ni
58-8
Tantalum
H
14
Tellurium
Oa
199-2
Thallium
0
16
Thorium
Pd
106-6
Tin
P
31
Titanium
Pt
197-6
Tungsten
K
39-1
Uranium
Ro
104-4
Vanadium
Rb
85-4
Yttrium
Ru
104-4
Zinc
8e
79 '4 ' Zirconium
Aff
Si
108
28
Na
23
Sr
87'fl
S
32
Ta
182
Te
128
Tl
204
Th
235
Sn
118
Ti
50
W
184
U
240
V
51-2
Y
92
Zn
65-2
Zr
89-6
Lithium
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrogen
Osmium
Oxygen
Palladium
Phosphorus
Platinum
Potassium
Rhodium
Rubidium
Ruthenium
Selenium
The combining weights indicate the proportions in which the
elements combine. Thus, assuming hydrogen, the lightest of
the elements, to be 1, or the unit of the series, the combining
weight of oxygen is 16 ; of iron, §6 ; of magnesium, 24; of
Biilphur, 32; and so on. When hydrogen and oxygen combine
it is in the ratio of 2 pounds of hydrogen, or else 1 pound of
hydrogen, to 16 pounds of oxygen, and two different compounds
thus result. When oxygen and magnesium combine it is in the
ratio of 16 pounds of oxygen to 24 of magnesium. Oxygen and
iron combine in the ratio of 16 of oxygen to 56 of iron ; or of 24
of oxygen (1£ times 16) to 56. Sulphur and oxygen combine in
the ratio of 32 of oxygen to 32 of sulphur; or of 48 to 32 of
sulphur. The combining weights are often called the atomic
weights.
The following is the manner of using the symbols : For the
compound consisting of hydrogen and oxygen in the ratio of 2
to 16, the chemical symJJ&l is H.,O, meaning 2 of hydrogen to 1
of oxygen. (This compound is water.) For the compound of
oxygen and magnesium just referred to, the symbol is MgO;
for the two compounds of oxygen and iron, FeO, protoxide of
iron ; Fe.,O3, sesquioxide of iron, the ratio of 1 to 1^ being ex-
pressed by 2 to 3 ; for the two compounds of sulphur and oxy-
gen, SOa and SO3.
Some of the elements so closely resemble one another that
their similar compounds are closely alike in crystallization and
other qualities, and they are therefore said to be isomorphous.
This is true of iron, magnesium, calcium, and two or three
other related elements. In one group of compounds of these
bases, the carbonates, the crystalline form for each is rhombohe-
78 CHEMICAL PROPERTIES OF MINERALS.
dral, and among them there is a difference of less than two d&.
grees in the angle of the rhouibohedron. Besides a carbonate
of calcium, a carbonate of magnesium, and a carbonate of iron,
there is also a carbonate of calcium and magnesium* in which
half of the calcium of the first of these carbonates is replaced
by half an atom of magnesium ; and another species in which
the base, instead of being all magnesium, is half magnesium and
half iron. By half is here meant half in the proportion of their
combining weights.
The replacement of one of these elements by the other, and
similar replacements among other groups of related elements,
run through the whole range of mineral compounds. Thus we
have sodium replacing potassium, arsenic replacing phosphorus
and antimony ', and so on.
In the combinations of oxygen and iron, as illustrated above,
oxygen is combined with the iron in different proportions.
FeO contains 1 of Fe (iron) to 1 of O (oxygen) and Fe^, or, as
it is often written, FeO3, contains § Fe to 1 of O. As the iron in
each of these cases satisfies the oxygen, it is evident that the
iron must be in two different states, (1) a protoxide state, and
(2) a sesquioxide state. One part of iron in this sesquioxide
state ( = f Fe) often replaces in compounds one part of iron in
the protoxide state (or IFe), with no greater change of quali-
ties than happens in the replacement of iron by magnesium, or
calcium, explained above ; or, avoiding fractions, 3 parts of Fe
in the protoxide state replaces 2Fe in the sesquioxide state.
Writing ¥e for the last 2Fe, the statement becomes 1 of Fe3
replaces 1 of Fe. Aluminium occurs only in the sesqui-
oxide state, and the ordinary symbol of the oxide is A14O8,
or AlO3. But it is closely related to iron in the sesquioxide
state, so that, using the same mode of expression as for iron,
1 of Al replaces 1 of Fe3, or 1 of Mjk, and so on. Similarly,
writing R for any metal, 1 of R replaces 1 of R3. Again, in
potash (K2O), soda (Na2O), lithia (Li.,O), water (H2O), one of
oxygen (O) is combined severally with 2 of K (potassium), of
Na (sodium), of Li (lithium), of hydrogen ; And hence 2K,
2Na, 2Li, that is, K2, Na2, Li2, may each replace in compounds
ICa, or IMg, etc.
The elements potassium, sodium, lithium, hydrogen, of which
it takes two parts to combine with 1 of oxygen, are called
monads. Other elements of the group of monads are rubidium,
ccesium, thallium, silver, and also fluorine, chlorine, bromine,
iodine. Still other elements combining by two parts in their
oxygen or sulphur compounds, etc., are nitrogen, phosphorus,
CHEMICAL COMPOSITION OF MINERALS. 79
intimony, boron, columbium, tantalum, vanadium, gold. For
example, for arsenic there are the compounds As2S, A.8SS3,
&s2O3, As,,O5, etc. Another characteristic of these elements of
the hydrogen, sodium, chlorine, and arsenic groups is that the
number of equivalents of the acidic element in the compounds
into which they enter is, with a rare exception, odd, and of the
1, 3, 5, etc., series, and on this account they are called in
chemistry perissads • while the other elements, in whose com-
pounds their number is of the 1, 2, 3, etc. (or 2, 4, 6) series,
are called artiads. An apparent exception exists under the
artiads in the sesqui oxides, but this does not alter the general
character of the series.
The facts above cited sustain the general statement that
Ca3, Mg3, Mn3, Zn3, Fe3, Al, Fe, Mn, have equivalent combin-
ing values, and hence in minerals often replace one another ;
and so also Ca, Mg, Mn, Zn, Fe, K2, Na2, Li2, H2, may replace
one another. Similarly, also, As2, or Sb3 replaces S in some
minerals.
With reference to the classification of minerals the elements
may be conveniently divided into two groups: (1) the Acidic,
and (2) the Basic. The former includes oxygen and the ele-
ments which were termed the acidi/iers and acidiftable elements
in the old chemistry. They are those which have been called
in mineralogy the mineralizing elements, since they are the
elements which are found combined with the metals to make
them ores, that is, to mineralize them. The basic are the rest
of the elements. The groups overlap somewhat, but this need
not be dwelt upon here.
The more important of the acidic elements are the following :
oxygen, fluorine, chlorine, bromine, iodine, sulphur, selenium,
tellurium, boron, chromium, molybdenum, tungsten, phosphorus,
arsenic, antimony, vanadium, nitrogen, tantalum, columbium,
carbon, silicon.
Again, among the compounds of these elements occurring in
tho mineral kingdom there are two grand divisions, the binary
and the ternary. The binary consist of one or more elements
of each of the acidic and basic divisions, and the ternary of one
or more elements of each of these two classes, along with oxy-
gen, fluorine, or sulphur as a third. The binary include the
sulphides, arsenides, chlorides, fluorides, oxides, etc., and tho
ternary the sulphates, chromates, borates, arsenates, pliospliates^
silicates, carbonates, etc., and also the sulpli-arsenites and sulph
antimonites, in which a basic metal (usually lead, copper, sil-
ver) is combined with arsenic or antimony and sulphur.
80 CHEMICAL PROPERTIES OF MINERALS.
The following are examples of the symbols of binary imd
ternary compounds :
1. Binary.
1. Sulphides, Selenides. — Ag2S = silver sulphide; Ag2Se =
silver selenide ; PbS = lead sulphide ; ZnS = zinc sulphide ;
FeS2 --— iron disulphide.
2. Fluorides, Chlorides, etc. — CaF2 = calcium fluoride ; AgCl
= silver chloride ; AgBr = silver bromide ; AgT = silver
iodide ; Nad = sodium chloride (common salt).
3. Oxides. — A12O3 = 3 ( Al^O) = aluminium sesquioxide ;
A s2O3 =. arsenic trioxide ; As.;O5 — arsenic pentoxide ; BaO =
barium oxide ; B.,O3 = boron trioxide (boracic acid) ; CaO =
calcium oxide (lime) ; CO2 = carbon dioxide (carbonic acid) ;
CrO3 = chromium trioxide (chromic acid) ; Cu2O = copper sub-
oxide ; CuO = copper oxide ; BeO = beryllium oxide ; H2O =
hydrogen oxide (water) ; FeO = iron oxide ; Fe2O3 = iron
sesquioxide ; PbO — lead oxide ; Li2O = lithium oxide ; MgO
= magnesium oxide ; MnO = manganese oxide ; Mn2O3 —
manganese sesquioxide ; MnO2 = manganese dioxide ; P2O5 =
phosphorus pentoxide ; K2O — potassium oxide ; SiO3 = silicon
dioxide (silica) ; Na2O = sodium oxide ; SrO = strontium ox-
ide ; SO., — sulphur dioxide (sulphurous acid) ; SO3 = sulphur
trioxide ; SnO2 = tin dioxide ; V2O5 = vanadium pentoxide
(vanadic acid) ; WO3 = tungsten trioxide (tungstic acid) ;
ZnO = zinc oxide ; ZrO2 — zirconium dioxide.
The composition of these compounds may be obtained from
the table of combining weights, page 76. For example, with
reference to the first of them (AgS), the table gives for the
combining weight of silver (Ag), 108, and for that of sulphur, 32.
The elements exist in the compound therefore in the proportion
of 108 to 32, and from it the composition of a hundred parts ia
easily deduced.
If the formula were (Ag, Pb)S, signifying a silver- and- lead
sulphide, and if the silver and lead were in the ratio of 1 to 1,
than half the combining weight of silver is taken; that is, 54,
and half the atomic weight of lead, which is 103 -5 ; and the
sum of these numbers, with 32 for the sulphur, expresses the
ratio of the three ingredients.
For A12O3 we find the combining weight of aluminium 27. 4 ;
doubling this for A12 makes 54*8. Again, for oxygen, we find
16 ; and three times 16 is 48. 54'S to 48 is therefore the ratio
CHEMICAL COMPOSITION OF MINERALS. 81
of aluminium to the oxygen in A.l.jO3, from which the percent-
age proportion may be obtained.
2. Ternary Oxygen Compounds.
Silicates. — Of these compounds there are two prominent
groups. In one of these groups the general formula is RO3Si,
and in the other R4 O4 Si. In both of these formulas R stands
for any basic elements in the protoxide state, as Ca, Mg, Fe,
etc., either alone or in combination. In the first of these for-
mulas the combining values of the basic element R and the
acidic element or silicon, as measured by their combinations
with oxygen, are in the proportion of 1 to 2, for R stands
for an element in the protoxide state, while Si stands for sili-
con, which is in the dioxide state, its oxide being a dioxide •
and hence the minerals so constituted are called Itisilicates. Ii
the second of these formulas this ratio is 2 to 2, or 1 to 1, and
hence these are called Unisilicates.
Multiplying these formulas by 3, they become R3O8Si3, and
(2R3) OjoSig ; and the same composition is expressed. In this
form the substitution of sesquioxide bases for protoxide may
be indicated : thus, RaR Oia Si3 signifies that half of the 2R3 is re-
placed by Al or Fe, or some other element in the sesquioxide
state.
There are also some species in which the ratio is 1 to less
than 1, and these are called Subsilicates.
The ratio here referred to (formerly known as the oxygen
ratio) is called the quantivalent ratio.
The other ternary compounds require no special remarks in
this place.
2. CHEMICAL REACTIONS.
1. Trials in the wet way.
1. Test for Carbonates. — Into a test tube put a little hydro-
chloric acid diluted with one half water, and add a small por-
tion in powder of the mineral. If a carbonate, there will be a
brisk effervescence caused by the escape of carbonic dioxide
(carbonic acid), when heat is applied, if not before. With cal-
cium carbonate no heat or pulverization is necessary.
2. Test for Gelatinizing /Silica. — Some silicates, when pow
6
82 CHEMICAL PROPERTIES OF MINERALS.
tiered and treated with strong hydrochloric acid, are decom-
posed and deposit the silica in a state of a jelly. The experi-
ment may be performed in a test tube, or small glass flask.
Sometimes the evaporation of the liquid nearly to dryness is
necessary in order to obtain the jelly. Some silicates do not
afford the jelly unless they have been previously ignited before
the blowpipe, and some gelatinizing silicates lose the power on
ignition.
3. Decomposability of Minerals by Acids. — To ascertain
whether a mineral is decomposable by acids or not, it is very
finely powdered and then boiled with strong hydrochloric acid,
or, in case of many metallic minerals, with nitric acid. In
some cases where no jelly is formed there is a deposit of silica
in fine flakes. With the sulphides and nitric acid there is often
a deposit of sulphur, which usually floats upon the surface of
the fluid as a dark spongy mass. Some oxides, and also some
sulphates and many phosphates, are soluble entirely without
effervescence. But many minerals resist decomposition. It is
sometimes difficult to toll whether a mineral is decomposed with
the separation of the silica or whether it is unacted upon. In
such a case a portion of the clear fluid is neutralized by soda
(sodium carbonate), and if anything has been dissolved it will
usually be precipitated.
Test for Fluorine. — Most fluorides are decomposed by strong
heated sulphuric acid, give out fluorine which will etch a glass
plate in reach of the fumes. The trial may be made in a lead
cup and the glass put over it as a loose cover.
2. Trials with the Blowpipe.
The blowpipe, in its simplest form, is merely a bent tube of
small size, eight to ten inches long, terminating at one end in a
minute orifice. It is used to concentrate the flame on a min-
eral, and this is done by blowing through it while the smaller
end is just within the flame.
The annexed figure represents the form commonly employed,
except that the tube is usually without the division at b. ft
contains an air chamber (o) to receive the moisture which ia
condensed in the tube during the blowing ; the moisture, unless
thus removed, is often blown through the small aperture and
interferes with the experiment. The jet, e/, is movable, and
it is desirable that it should be made of platinum, in order that
it may be cleaned when necessary, either by high heating or
CEEMICAL COMPOSITION OF MINERALS.
83
_y immersion in an acid. The screw at b is for the purpose of
shortening the tube one-half so as to make it more convenient
for the pocket of the field mineralogist. It is un-
screwed for this purpose, and the smaller part put
within the larger.
In using the blowpipe it is necessary to breathe
and blow at the same time, that the operator may
not interrupt the flame in order to take breath.
Though seemingly absurd, the necessary tact may
easily be acquired. Let the student first breathe a
few times through his nostrils while his cheeks are
inflated and his mouth closed. After this practice
lot him put the blowpipe to his mouth and he will
find no difficulty in breathing as before while the
muscles of the inflated cheeks are throwing the air
th°iy contain through the blowpipe. When the air
is nearly exhausted the mouth may again be filled
through the nose without interrupting the process
of blowing.
The flame of a candle, or a lamp with a large
wick may be used, and when so it should be bent
in the direction the flame is to be blown. But it is far better,
when gas can be had, to use a Bunsen's burner.
The flame has the form of a cone, yellow without and blue
within. The heat is most intense just beyond the extremity of
the blue flame. In some trials it is necessary that the air
should not be excluded from the mineral during the experiment,
aud when this is the case the outer flame is used. The outer is
called the oxidizing flame (because oxygen, one of the consti-
tuents of the atmosphere, combines in many cases with some
parts of the assay, or substance under experiment), and the in-
ner the reducing flame. In the latter the carbon and hydrogen
of the flame, which are in a high state of ignition, and which are
einloeed from the atmosphere by the outer flame, tend to unite
with the oxygen of any substance that is inserted in it. Hence
substances are red-iced in it.
The mineral is supported in the flame either on charcoal; or
\ -f means of steel forceps (as in the annexed figure) with plati-
num extremities (a 6), opened by pressiu^r on the pins pp\ or
on platinum wire or foil.
84 CHEMICAL PROPERTIES OF MINERALS.
To ascertain the fusibility of a mineral, the fragment for the
platinum forceps should not be larger than the head of a pin,
and, if possible, should be thin and oblong, so that the extrem-
ity may project beyond the platinum. The fusible metals alloy
readily with platinum. Hence compounds of lead, arsenic, an-
timony, etc., must be guarded against. These compounds are
tosted 011 charcoal. The forceps should riot be used with the
'luxes, but instead either charcoal or the platinum wire or foil.
The charcoal should be firm and well burnt ; that of soft
wood is the best. It is employed especially for the i eduction
of oxides, in which the presence of carbon is often necessary,
and also for observing any substances whicb may pass off and
be deposited on the charcoal around the assay. These coatings
are usually oxides of the metals, which are formed by the oxi-
dation of the volatile metals as they issue from the reduction
flame.
The platinum wire is employed in order to observe the ac-
tion of the fluxes on the mineral, and the colors which the
oxides impart to the fluxes when dissolved in them. The wire
used is No. 27. This is cut into pieces about three inches long,
and the end is bent into a small loop, in which the flux is fused.
This makes what is called a bead. When the experiment is
complete the beads are removed by uncoiling the loop and draw-
ing the wire through the finger nails. After use for awhile the
end breaks off, because platinum is acted upon by the soda, and
then a new loop has to be made. Dilute sulphuric acid will
remove any of the flux that may remain upon it after a trial
has been made.
Glass tube is employed for various purposes. It should be
from a line to a fourth of an inch in bore. It is cut into pieces
four to six inches long, and used in some cases with both ends
open, in others with one end closed. In the closed tube, either
heated directly over the Bunsen burner, or with the aid of the
blowpipe, volatile substances in the assay are vaporized and
condensed in the upper colder part of the tube, where they
may be examined by a lens if necessary, or by further heating.
The odor given off may also be noted, and the acidity of any
ftimeF bj inserting a small strip of litmus paper in the mouth
of the tube. The closed tube is used to observe all the effects
tlv*t may take place when a substance is heated out of contact
with the air. In the open tube the atmosphere passes through
the tube in the heating, and so modifies the result. The assay
is placed an inch or an inch and a quarter from the lower end
of the tube ; the tube should be held nearly horizontally, to
BLOWPIPE REACTIONS. 85
prevent the assay from falling out. The strength of the
draught depends upon the inclination of the tube, and in special
cases it should be inclined as much as possible.
The most common fluxes are borax (sodium bi-borate), salt
of phosphorus (sodium and ammonium phosphate), and soda
(sodium carbonate, either the carbonate or bi-carbonate of soda
of the shops.) These substances, when fused and highly heated,
arc very powerful solvents for metallic oxides. They should
be pure preparations. The borax and soda are much the most
important. In using the platinum wire, the loop may be highly
heated, and then a portion of the borax or soda may be taken
up by it, and by successive repetitions of this process the re-
quisite amount of the flux may be obtained on the wire. Then,
by bringing the melted flux of the loop into contact with one
or more grains of the pulverized mineral, the assay is made
ready for the trial. With soda and quartz a perfectly clear
globule is obtained, cold as well as hot, if the flux is used in
the right proportion. Some oxides impart a deep and charac-
teristic color to a bead of borax. In other cases the color
obtained is more characteristic when salt of phosphorus is em-
ployed. The color obtained in the outer flame is often differ-
ent from that which is obtained in the inner flame. The beads
are sometimes transparent and sometimes opaque. If too much
substance is employed the beads will be opaque when it is de-
sired that they should be transparent. In such cases the
experiment may be repeated with less substance. In many
cases pulverized mineral and the flux, a little moistened, are
mixed together into a ball upon charcoal, especially in the ex-
periments with soda.
In the examination of sulphides, arsenides, antimonides and
related ores, the assay should be roasted before using a flux, in
order to convert the substance into an oxide. This is done by
spreading the substance out on a piece of charcoal and exposing
it to a gentle heat in the oxidizing flame. The sulphur, arsenic,
antimony, etc., then pass off as oxides in the form of vapors,
leaving the non-volatile metals behind as oxides. The escap-
ing sulphurous acid gives the ordinary odor of burning sulphur ;
arsenous acid, from arsenic present, the odor of garlic, or au
alliaceous odor ; seleuous acid, from selenium present, the odor
of decaying horse-radish ; while antimony fumes are dense white,
and have no odor.
The following is the scale of fusibility which has been adopted,
beginning with the most fusible :
1. STIBNITE. — Fusible in large pieces in tUe candle flame.
86 CHEMICAL PROPERTIES OF MINERALS.
2. NATROLITE. — Fusible in small splinters iii the candle
flame.
3. ALMANDINE, or bright red GARNET.— Fusil ie in large
pieces with ease in the blowpipe flame.
4. ACTINOLITE. — Fusible in large pieces with difficulty in tho
blowpipe flame.
5. ORTHOCLASE, or common feldspar. Fusible in small
splinters with difficulty in the blowpipe flame.
6. BUONZITE. — Scarcely fusible at all.
The color of the flame is an important character in connection
with blowpipe trials. When the mineral contains sodium tho
color of the flame is deep yellow, and this is generally true in
spite of the presence of other related elements. When sodium
(or soda) is absent, potassium (or potash) gives a pale violet
color; calcium (or lime) a pale reddish yellow ; lithium, s, deep
purple -red, as in lithia-inica ; strontium, a bright red, this ele-
ment being the usual source of the red color in pyrotechny ;
copper, emerald green ; phosphates, bluish green ; boron, yellow-
ish green ; copper chloride, azure blue. Beads should be exam-
ined by daylight only, and should be held in such position that
Mie color is not modified by green trees or other bright objects
when examined by transmitted light. Colored flames are seen
to best advantage when some black object is beyond the flame
in the line of vision.
It is also to be noted, in the trials, whether the assay heats
up quietly, or with decrepitation ; whether it fuses with effer-
vescence or not, or with intumescence or not ; whether it fuses
to a bead which is transparent, clouded, or opaque ; whether
blebby (containing air-bubbles or not) ; whether scoria-like or
not.
Testing for Water. — The powdered mineral is put at the
bottom of a closed glass tube, and after holding the extremity
for a moment in the flame of a Bunsen's burner, moisture, if
tiny is present, will have escaped and be found condensed on the
inside of the tube, above the heated portion. Litmus or tur-
meric paper is used to ascertain if the water is acid or alkaline,
acids changing the blue of litmus paper to red, and alkalies the
yellow of turmeric paper to brown.
Testing for an Alkali. — If the fragment of a mineral, heated
in the platinum forceps, contains an alkali, it will often, after
being highly heated, give an alkaline reaction when placed,
after moistening, on turmeric paper, turning it brown. This
lest is applicable to those salts which, on heating, part with a
portion of their acid and are rendered caustic thereby. Such
BLOWPIPE REACTIONS. 87
we the carbonates, sulphates, nitrates, and chlorides of the
alkaline metals.
Testing for Alumina or Magnesia, — Cobalt nitrate, in solu-
tion, is used to distinguish an infusible and colorless mineral
containing aluminium from one -containing magnesium. A
fragment of the mineral is first ignited, and then wet with a
drop or two of the cobalt solution and heated again. The alu-
minium mineral will assume a blue color, and the magnesium
mineral a pale red or pink.
Any fusible silicate, when moistened with cobalt nitrate and
ignited will assume a blue color, hence this test is only deci-
bive in testing infusible substances.
Infusible zinc compounds, when moistened with cobalt nitrate,
assume a green color.
Testing for Lithium. — Some lithium minerals give the
bright purple-red flame if simply heated in the platinum for-
ceps. In other cases mix the powdered mineral with one part
of fiuorite and one of potassium bi-sulphate. Make the whole
into a paste with a little water, and heat it on the platinum
wire in the blue flame.
Testing for Boron. — When the bright yellow-green of boron
is not obtained directly on heating the mineral containing it,
one part of the powdered mineral should be mixed with ono
part of powdered fluorite and three of potassium bi-sulphate ;
and then treated as in the last. The green color appears at the
instant of fusion.
Testing for Fluorine. — To detect fluorine in fluorides mix a
little of the powdered substance with potassium bi-sulphate,
put the mixture in a closed glass tube and fuse gently. The
bi-sulphate gives oft* half of its sulphuric acid at a high temper-
ature, which acts powerfully on anything it can attack. If a
fluoride is present, hydrofluoric acid will be given off, and the
walls of the tube will be found roughened and etched when the
tube is broken open and cleaned after the experiment. If a
silicate containing fluorine be powdered and mixed with previ-
ously fused salt of phosphorus, and heated in the open tube by
blowing thb flame into the lower end of the tube, hydrofluoric
acid is given off, and the tube is corroded just above the assay.
Silicates. — Nearly all silicates undergo decomposition with
salt of phosphorus, setting free the silica, forming a bead which
is clear while hot and has a skeleton of silica floating in it,
The bead is sometimes clear also when cold.
Iron. — Minerals containing much iron produce a magnetic
globule when highly heated. Usually the reducing flame ia
88 CHEMICAL PROPERTIES OF MINERALS.
required, and sometimes the use of soda. With borax iron
gives a bead with the oxidizing flame which is yellow while
hot, but colorless on cooling, and which in the reducing flame
becomes bottle green.
Cobalt. — Minerals containing cobalt afford, with borax, a
beautiful blue bead. If sulphur or arsenic is present it should
be first roasted off on charcoal.
Nickel. — In the oxidizing flame with borax, the bead i? violet
when hot, and red-brown on cooling. In the reducing flame
the glass becomes gray and turbid from the separation of metal-
lic nickel, and on long blowing, colorless. The reaction is ob-
scured by the presence of cobalt, iron, and copper.
Manganese. — With borax in the oxidizing flame, the bead is
a deep violet-red, and almost black if too much of the mineral
is used. To see the color examine by transmitted light. With
soda in the same flame the opaque bead is bluish green.
Chromium. — With borax, both in the oxidizing and reducing
flame, the bead is bright emerald green.
Titanium. — Titanium oxide with salt of phosphorus on
platinum Avire in O.F. dissolves to a clear glass, which, if
much is present, becomes yellow while hot and colorless on
cooling; but in R.F. the hot globule obtained in O.F. reddens
and assumes finally a beautiful violet color. On charcoal with
tin the glass becomes violet if there is not too much iron
present.
Zinc. — Zinc and some of its compounds when heated cover
the charcoal with zinc oxide, which is yellow while hot, but
white on cooling ; and this coating, if wet with cobalt solution
and then heated, assumes a fine yellowish-green color which
is most distinct when cold.
Lead., copper, tin, silver, when characterizing a mineral, give
with soda in the reducing flame minute metallic globules, which
are malleable, or may be cut with a knife ; they can be distin-
guished by their well-known physical properties. When two
or more of these metals occur together, or iron is also present^
the globules consist usually of an alloy of the metals.
Lead. — When the mineral is treated with soda on charccal
in the oxidizing flame, the yellow oxide coats the charcoal
around the assay.
Copper. — The flame is colored, in most cases, bright green.
With borax or salt of phosphorus in the reducing flame the
bead is red. In the oxidizing flame the bead is green when
hot and becomes blue or greenish blue on cooling.
Mercury. — Heated in the closed tube with soda, a sublimate
of metallic mercury covers the inside of the tube.
BLOWPIPE REACTIONS. 89
Silver. — If the silver is in very small quantities, as in argen-
tiferous galena, the assay is put into a little cup made of bone
ashes (bone burnt white and finely pulverized), and subjected
to the oxidizing flame ; the lead is oxidized and sinks into the
bone ashes, leaving the silver a brilliant globule on the cupeL
Before cupellation it is often necessary to melt the assay to-
gether with some borax and pure lead in a hole on charcoal.
By this process the sand and impurities are removed, and a
globule of lead is obtained which contains all the silver, and
which may be separated from the slag and be oxidized as
above.
Arsenic. — In the closed tube arsenic sublimes and coats the
tube with brilliant grains, or a crust, of metallic arsenic. If
the mineral contains sulphur as well as arsenic, sublimates of
the yellow and red arsenic sulphides (orpiment and realgar) are
often formed. In the open tube a sublimate of white arsenous
acid is formed, Avhich condenses in bright crystals on the walls
of the tube, and a strong garlic odor is given off. On charcoal
the alliaceous odor is at once perceptible.
Antimony. — In the closed tube, when sulphur is present, the
assay yields a sublimate which is black when hot, brown-red
when cold. In the open tube dense white vapors are given off
and a white amorpJwus sublimate covers the inside of the tube,
which, for the most part, does not volatilize when reheated.
On charcoal the assay yields dense, white, inodorous fumes.
Tellurium. — In the open tube a white or grayish sublimate
is obtained, which may be fused to clear, colorless drops. Ou
charcoal a white coating is produced, and the reducing flame is
colored green.
Sulphur. — All sulphates, and other sulphur-bearing miner-
als, when heated on charcoal with soda, produce a dark, yellow-
ish brown sulphide of sodium ; and if a fragment of this is
moistened and placed on a polished plate of silver, it turns it
immediately brownish black, or black. Pure soda, and a flame
wholly free from sulphur, is needed for the trial, since the least
trace of sulphur in either vitiates the result. Many sulphides
give fumes of sulphur on charcoal. The higher sulphides afford
these fumes in a closed tube. The others afford fumes of sul-
phurous acid in an open tube, which redden a moistened bluo
litmus paper placed in the upper end of the tube.
Selenium. — Selenium and many selenides afford a steel-gray
sublimate in an open tube, which at the upper edge appears
red. On charcoal brown fumes are given off with an odor like
that of decaying h( rse-radish.
90 CHEMICAL PROPERTIES OF MINERALS.
Chlorides. — If a bead of borax be saturated with copper
oxide, and then dipped into the powder of a substance which ia
to be tested for chlorine, a chloride of copper is formed which
imparts an azure blue color to the flame if any chlorine is pres-
ent. If dissolved in water or nitric acid a little silver nitrate
produces a dense white precipitate of silver chloride.
Nitrates. — A nitrate, if fused on charcoal, will defkgrate with
brilliancy, owing to the decomposition of the nitrate and the
union of its oxygen with the carbon.
Phosphates. — Phosphates give a dirty green color to the blow-
pipe flame. The color is more distinct if the substance is first
moistened with sulphuric acid. If a phosphate is pulverized
and heated in a closed glass tube with some bits of magnesium
wire, the phosphoric acid is reduced, and when the fusion is
moistened with water the very disagreeable odor of phosphuretted
hydrogen is obtained.
For a fall account of blowpipe reactions recourse must be
had to a treatise on the blowpipe. The best and fullest Ameri-
can work on the subject is Prof. Gr. J. Brush's " Manual of De-
terminative Mineralogy, with an Introduction on Blowpipe
Analysis."
In this work the following abbreviations are used in speaking
)f blowpipe reactions :
B.J3. = before the blowpipe ; O.F. = oxidizing flame ;
R.F. = reducing flame.
CLASSIFICATION. 93
4. DESCRIPTIONS OF MINERALS.
CLASSIFICATION.
SOME of the prominent points in the classification of minerals
adopted in the following pages are given in connection with the
remarks on chemical composition, pages 79.
Many instructors in the science, and most of those who con-
sult a work on Mineralogy for practical purposes, prefer an ar-
rangement of the ores which groups them under the head of the
metal prominent in their constitution. The method of group-
ing mineral species according to the basic element has therefore
been here, to a large extent, followed. An exception has been
made in the case of the silicates, because it is with them almost
impracticable, on account of the number of basic elements they
often contain ; and, moreover, not more than half a dozen use-
ful ores exist among them. The silicates therefore, which in-
clude the larger part of all minerals, make together one of the
grand divisions in the classification, and they are presented ac-
cording to their natural groups, in the same order as in the
larger mineralogy.
The prominent subdivisions in the classification are as fol-
lows :
I. THE ACIDIC DIVISION, including the acidic elements oc-
curring native, and the native compounds of the acidic elements
with one another.
II. THE BASIC DIVISION, including the basic elements occur-
ring native, and the native binary and ternary compounds of
the basic elements — the silicates excepted.
III. SILICA and the SILICATES.
IV. THE HYDROCARBON COMPOUNDS, including mineral oils,
resins, wax, and coals.
The following are the chief subdivisions under these head» :
I. ACIDIC DIVISION.
1. Sulphur Group. — The chief oxide a trioxide, its formula
K O3. Includes Sulphur and sulphur oxides ; Tellurium and
tellurium oxides; Molybdenum sulphide and oxide; Tungsten
oxide.
92 DESCRIPTIONS OF MINERALS.
2. Boron Group. — The chief oxide a trioxide, its formula
R2 O3. Includes compounds of Boron with oxygen.
3. Arsenic Group. — The chief oxide a pentoxide, its formula
E,O5. Includes Arsenic arid arsenic sulphides and oxides ; An-
tii.iony and antimony sulphide, arsenide and oxides ; Bismuth
and bismuth sulphide, telluride and oxide.
4. Carbon Group. — The chief oxide a dioxide, its formula
R O.2. Includes Carbon (Diamond, Graphite) and carbon diox-
ide. (Quartz, Si O.2) belongs here chemically, but is placed with
the Silicates.)
II. BASIC DIVISION.
Gold ; Silver ; Platinum and Iridium ; Palladium ; Quick-
silver ; Copper ; Lead ; Zinc ; Cadmium ; Tin ; Titanium ; Co-
balt and Nickel ; Uranium ; Iron ; Manganese ; Aluminium ;
Cerium, Yttrium, Lanthanum, Didymiurn and Erbium ; Mag-
nesium; Calcium; Barium and Strontium; Potassium and
Sodium ; Ammonium ; Hydrogen.
III. SILICA AND SILICATES.
1. Silica.
2. Anhydrous Silicates.
1. Bisilicates.
2. Unisilicates.
3. Subsilicates.
3. Hydrous Silicates.
1. General section of Hydrous Silicates.
2. Zeolite section.
3. Margarophyllite section.
IV. HYDROCARBON COMPOUNDS.
1. Oils, Resins, Wax.
2. Asphaltum, Coals.
GENERAL REMARKS ON ORES.
An ore, in the miueralogical sense of the word, is a mineral
compound in which a metal is a prominent constituent. In the
GENERAL REMARKS ON ORES. 93
miner's use of the term it is a mineral substance that yields, by
metallurgical treatment, a valuable metal, and especially when
it profitably yields such a metal. In the former sense, galena,
the common ore of lead, is, if it contains a little silver, an
argentiferous lead-ore ; while, in the latter, if there is silver
enough to make its extraction profitable, it is a silver-ore.
Further than this, where a native metal, or other valuable
metallic, mineral, is distributed intimately through the gangue,
the mineral and gangue together are often called the ore of the
metal it produces.
We have beyond to do with ores only in the mineralogical
sense.
Ores are compounds of the metals, not metals in the native
state. The more common kinds are compounds of the metala
with Sulphur (sulphides) ; with Arsenic (arsenides) ; with Sul-
phur and Arsenic (sulph-arsenides) ; with sulphur in ternary
combination along with arsenic, antimony or bismuth (making
compounds called sulph-arsenites, sulph-antimonites, sulpho-bis-
mutites) ; with Selenium (selenides) ; with Tellurium (tellu-
rides) ; with Oxygen (oxides) ; with Chlorine, Iodine, or Bro-
mine (chlorides, iodides, or bromides) ; with oxygen in ternary
combination with carbon (making carbonates) ; with Sulphur
(making sulphates) ; with Arsenic (making arsenates) ; with
Phosphorus (making phosphates) ; with Silicon (making sili-
cates).
Gold and platinum are, with rare exceptions, found only na-
tive, or intimately mixed in essentially the pure state with some
metallic minerals. Tellurium is the only acidic element that
occurs combined with gold in nature.
Silver is found in the state of sulphide, antimonide, selenide,
telluride, sulph-arsenites and sulph-antimonites, but never as
oxide or in oxygen ternary compounds.
Quicksilver occurs in the state of sulphide (the common ore) ;
also in that of selenide and sulph-arsenites.
Copper and lead occur in the state of sulphides (common ores),
arid also in all the binary and ternary states mentioned above.
Zinc is known in the state of sulphide (very common),
ojddo, carbonate, sulphate, silicate (all, excepting the sulphate,
valuable as ores) ; and Cadmium in that of sulphide only.
Tin occurs in the state of oxide (the common ore), and sul-
phide.
Cobalt and Nickel occur in the states of sulphide, arsenide,
sulph-arsenides, antimonide, oxide, sulphate, arsenate, carbon-
ate ; and nickel in that also of a silicate.
94 DESCRIPTIONS OF MINERALS.
Iron occurs in the state of sulphide (very common, but not
useful as an ore of iron), of arsenide, sulph-arsenide, oxide (the
common ores of iron), carbonate (useful ore), sulphate, arsen-
ate, phosphate, silicate.
Manganese occurs in the state of sulphide (rare), arsenide
(rare), oxide (the common ores), carbonate, sulphate, phosphate^
silicate.
1. MINEKALS CONSISTING OF THE ACIDIC
ELEMENTS.
Oxygen might properly be included in this section, since it
occurs native in the atmosphere mixed with nitrogen, consti-
tuting 21 per cent, of it. But this mention of it is all that ia
necessary. The ternary compounds, in which, as in sulphuric
acid, hydrogen is the basic element, are here included. Chlor*
ine, bromine, and iodine do not occur native, and neither do their
oxides, nor any compounds with acidic elements, and hence these
elements are not represented under this division. The same is
true of selenium and chromium of the sulphur group, and of
vanadium, tantalum, and columbium of the arsenic group.
I. SULPHUR GROUP.
Native Sulphur.
Trimetric. — In acute octahedrons, and secondaries to thii
form, with imperfect octahedral cleavage. 1 A 1 (in same pyra-
1. 2.
mid) = 10(5° 25' and 85° 07'; lAl (over base) = H3C 23'.
Also massive.
Color and streak sulphur-yellow, sometimes orange-yellow.
BULPHUB. 95
Lustre resinous. Transparent to translucent. Brittle. H.=
1*5 — 2-5. G.= 2.07. Burns with a blue flame and sulphurous
odor. In a closed tube it is wholly volatilized and redeposited
on the wall of the tube.
Native sulphur is either pure, or contaminated with clay or
bitumen. It sometimes contains selenium, and has then an
orange-yellow color.
Diff. It is easily distinguished by its burning with a blue
flame, and the sulphur odor then afforded.
Obs. The great repositories of sulphur are either beds of
gypsum and the associate rocks, or the regions of active or ex-
tinct volcanoes. In the valley of Noto and Mazzai o in Sicily,
at Conil near Cadiz in Spain, Bex in Switzerland, and Cracow
in Poland, it occurs in the former situation. Sicily and the
neighboring volcanic islands, Vesuvius and the Solfatara in its
vicinity, Iceland, Teneriffe, Java, Hawaii, New Zealand, De-
ception Island, and most active volcanic regions afford more or
less sulphur. The native sulphur of commerce is brought
largely from Sicily, where it occurs in beds along the central
part of the south coast and to some distance inland. It under-
goes rough purification by fusion before exportation, which
separates the earth and clay with which it occurs.
On the Potomac, twenty-five miles above Washington, sul-
phur has been found associated with calcite in a gray com-
pact limestone ; sparingly about springs where hydrogen sul-
phide is evolved, in New York and elsewhere ; in cavities where
iron sulphides have decomposed, and in many coal mines ; near
Borax Lake, in California ; Inferno, Humboldt County, Nevada,
abundant.
The sulphur of commerce is also largely obtained from copper
and iron pyrites, it being given off during the roasting of the»e
ores.
Sulphur when cooled from fusion, or above 232° F., crys-
tallizes in oblique rhombic prisms. When poured into water
at a temperature above 300° F. it acquires the consistency of
soft wax, and is used to take impressions of gems, medals, etc.,
which harden as the sulphur cools. The uses of sulphur for
gunpowder, bleaching, the manufacture of sulphuric acid, and
also in medicines, are well known. Sulphur occurs in various
ores as sulphides and sulphates. Among the sulphides are
pyrite, an iron sulphide ; pyrrhotite, another iron sulphide ;
galena, a lead sulphide, the common ore of lead ; chalcopyrite,
or yellow copper ore, a copper and iron sulphide; cinnabar, a
mercury sulphide ; argentite, a silver sulphide, etc.
96 DESCRIPTIONS OF MINERALS.
Sulphuric and Sulphurous Acids.
Sulphuric acid is occasionally met with around volcanoes,
and it is also formed from the decomposition of hydrogen
sulphide about sulphur springs.
It is intensely acid. Composition, Sulphur teroxide (SOJ
81*6, water 18-4=100, it being chemically hydrogen sul-
phate. Occurs in the waters of Rio Vinagre, South America ;
also in Java, and at Lake de Taal on Luzon, in the East
Indies ; in Genesee Co., N. Y. ; and at Tuscarora, St. Davids,
and elsewhere, Canada West.
Sulphurous acid, or sulphur dioxide (S0.2), is produced
when sulphur burns, and causes the odor perceived during
the combustion. It is common about active volcanoes. It
destroys life and extinguishes combustion. Composition,
Sulphur 50-00, oxygen 50-00.
Native Tellurium.
Hexagonal ; R/\R = 86° 57'. Occurs sometimes in
six-sided prisms with perfect lateral cleavage ; but is com-
monly granular massive. Color and streak tin-white. Brit-
tle. H. =2-2-5. G. =6-1-6 -3.
Sometimes contains a little iron, and also a trace of gold.
In an open tube, b. B. yields a wrhite inodorous sublimate,
which may be fused to colorless transparent drops ; and on
charcoal fuses and volatilizes, tinging the flame green, and
covering the charcoal with white tellurium dioxide.
Obs. Occurs in Hungary and Transylvania ; also, Boulder
Co., Colorado, at the Red Cloud Mine ; in Magnolia District
at the Keystone, Dun River, and other mines ; in the BaJ-
lerat District at Smuggler Mine ; in Central District at the
John Jay Mine, where masses of 25 pounds weight are re-
ported to have been found.
Tellurium is also a constituent of ores of silver and lead (pp. 118, 149),
and these are the chief sources of the metal.
Tellurite or Tellurous acid, Te02, occurs at the Keystone, Smug-
gler, and John Jay Mines ; especially the last, where it is in minute
white or yellowish crystals having one eminent cleavage.
Molybdenite. — Molybdenum Sulphide.
Hexagonal. In hexagonal plates, or masses, thin foliated,
like graphite, and resembling that mineral. H.= 1-1-5.
G. = 4-45-4-8. Color pure lead- gray ; streak the same,
BORON GROUP. 9?
slightly inclined to green. Thin laminae very flexible ; not
elastic ; leaves a trace on paper, like graphite, but its color
is slightly different, being bluish-gray.
Composition. Mo S2= Sulphur 41-0, molybdenum 59*0=
100. B.B. infusible, but when heated on charcoal, sulphur
fumes are given off, which are deposited on the coal. Dis-
solves in nitric acid, excepting a gray residue.
• Diff. Resembles graphite, but differs in its paler color
and streak, and also in giving fumes of sulphur when heated,
as well as by its solubility in nitric acid.
Obs. Occurs in granite, gneiss, mica schist, and allied
rocks ; also in granular limestone. It is found in Sweden,
at Arendal in Norway, in Saxony, Bohemia, at Caldbeck
Fell in Cumberland, and in the Cornish mines.
In the United States it occurs in Maine at Blue Hill Bay,
Camdage Farm, Brunswick, and Bowdoinham ; in New
Hampshire at Westmoreland, Landaff, and Franconia ; in
Massachusetts at Shutesbury and Brimfield ; in Connecticut
at Haddam and Saybrook ; in New York near Warwick ; in
New Jersey near the Franklin Furnace.
Molybdenum does not occur native. An oxide is occa-
sionally found in yellow incrustations on molybdenite, as a
result of its alteration. It occurs, combined with lead, as a
molybdate (page 151), and this is the only native salt con-
taining it. The name molybdenum is from the Greek mo-
luMaina, meaning mass of lead, and alludes to the resem-
blance of molybdenite to graphite.
TUNGSTITE, or Tungstic ochre. A yellow powder or incrustation oc-
curring with wolfram, and a result of its decomposition. Occasionally
observed at Lane's Mine, Monroe, Conn.
Besides this oxide there are tac native compounds, iron tungstate
or wolfram (p. 183), lead tungstate (p. 151), and calcium tungstate.
Tungsten also occurs sparingly in some ores of columbium, as in cer-
tain varieties of the minerals pyrochlore, columbite, and yttro-colum-
bite.
II. BORON GROUP.
In Boron, as in the Sulphur group, the most prominent
oxide is a teroxide.
Sassolite. — Boracic Acid. Sassolin.
Occurs in small scales, white or yellowish. Feel smooth and
unctuous. Taste acidulous and a little saline and bitter.
98 DESCRIPTIONS OF MINERALS.
G. =1*48. Composition, H6 06 Bo2 = Boron teroxide 56-4,
water 43-6. It is strictly hydrogen borate. Fuses easily
in the flame of a candle, tinging the name at first green.
Found at the crater of Vulcano, and also at Sassoin Italy,
whence it was called Sassolin. The hot vapors of the la-
goons of Tuscany afford it in large quantities. The vapors
are made to pass through water, which condenses them ; and
the water is then evaporated by the steam of the springs,
and boracic acid obtained in large crystalline flakes. It
still requires purification, as the best thus procured contains
but 50 per cent, of the pure acid. Occurs also in the waters
of Lick Springs, Tehama Co., and Borax Lake, Lake Co.,
California, where it was first observed, through their evapo-
ration, by Dr. J. A. Veatch, in 1856. It has since been
obtained from the waters of Mono, Owens, and other lakes.
It exists sparingly in the waters of the ocean. But in all
these waters, it is probably in combination.
Boron occurs usually in the condition of magnesium, calcium, and
sodium borates (pp. 206, 212, 227) ; and rarely as an iron borate (p. 182),
or ammonium borate (p. 231). It also occurs in the silicates, tourma-
line, danburite, axinite, and datolite, in which it is easily detected by
the blowpipe reaction (p. 87).
III. THE ARSENIC GROUP.
The elements of the Arsenic group occurring among
minerals are, arsenic, antimony, bismuth, phosphorus, ni-
trogen, vanadium, tantalum, columbium. Of these arsenic,
antimony, and bismuth occur native, and as sulphides ; also,
in combination with other metals, constituting arsenides,
antimonides, bismutides ; and, along with sulphur also, mak-
ing sulpharsenites, sulphantimonites, sulphbismutites. In
addition, they all, excepting bismuth, enter into the consti-
tution of a series of native ternary oxygen compounds or
salts, called severally, arsenates, antimonates, phosphates,
nitrates, vanadates, tantalates, columbates.
The chief oxide has the general formula K2 05.
Native Arsenic.
Khombohedral. R/\R=85° 41'. Cleavage basal, imper-
fect. Also massive, columnar, or granular.
THE ARSENIC GROUP. 99
Color and streak tin-white, but usually dark grayish from
tarnish. Brittle. H.=3-5. G. =5-65-5-95.
B.B. volatilizes very readily before fusing, with the odor
of garlic ; also burns "with a pale bluish flame when heated
just below redness.
Obs. Occurs with silver and lead ores. It is found in
considerable quantities at the silver mines of Freiberg and
Sclmeeberg; also in Bohemia, the Hartz, at Kapnik in
Upper Hungary, in Siberia in large masses, and elsewhere.
In the United States it has been observed at Haverhill
and Jackson, N. H., and at Greenwood, Me.
Orpiment — Yellow Arsenic Sulphide.
Trimetric. Cleavage highly perfect in one direction. In
foliated masses, and sometimes in prismatic crystals. Color
and streak fine yellow. Lustre brilliant pearly, or metallic
pearly, on the face of cleavage. Subtransparent to translu-
cent ; sectile. H. = 1 -5-2. G. - 3 -4-3 -5.
Composition. As2S3 = Sulphur 39-0, arsenic 61*0. Wholly
evaporates before the blowpipe with an alliaceous odor, and
on charcoal burns with a blue flame.
From Hungary, Koordistan in Turkey in Asia, China, and
South America/ Occurs at Edenville, N. Y., as a yellow
powder, resulting from the decompositon of arsenical iron.
Realgar is another arsenic sulphide. It has a fine clear red color,
aurora red to orange, and occurs transparent or translucent ; H. =
15-2; GK =335-3 65; Composition, As S= Sulphur 29 '9, arsenic 70'1.
Like the preceding before the blowpipe. From Hungary, Bohemia,
Saxony, the Hartz, Switzerland, and Koordistan in Asiatic Turkey.
It has been observed in the lavas of Vesuvius.
Realgar is one of the ingredients of white Indian fire, often used as a
signal light. Orpiment is a coloring ingredient in the pigment called
king's yellow, in which it is mixed with arsenious acid.
Arsenolite. — White Arsenic.
Isometric. In minute capillary crystals, and botryoidal
or stalactitic. Color white. Soluble ; taste astringent,
sweetish. H.=l-5. G.=3'7.
Composition. As2 03= Arsenic 75-8, oxygen 24-2 = 100.
This is the same compound with the common arsenic of
the shops. It is found but sparingly native, accompanying
ores of silver, lead, and arsenic in the Hartz, Bohemia, and
elsewhere. It is a well-known poison.
100 DESCRIPTIONS OF MINERALS.
Claudetite is the same compound in trimetric crystallizations, from
Portugal.
General Remarks. — Arsenic is obtained for commerce chiefly from
arsenopyrite(ormispickel), an iron sulph-arsenide, and from the nickel
and cobalt arsenides, by first roasting off the sulphur, and then con-
densing the arsenic, in the state of As2 O3 (" arsenous acid ") in large
chambers. To obtain the material pure it is usually sublimed again
in iron pots, in the upper part of which (artificially kept cool) it is
condensed, mostly in a half-fused vitreous condition. To reduce the
oxide to the metallic state it is heated with charcoal. In Devon and
Cornwall the arsenical ores occur with the tin ore, and a large amount
of white arsenic is made. The metal arsenic forms a small part of
some alloys ; the most important is that with lead for shot making.
Native Antimony.
Khombohedral ; Rf\R—ST 35'. Usually massive, with a
very distinct lamellar structure ; sometimes granular. Color
and streak tin-white. Brittle. H. = 3-3 -5. G-. = 6 -6-6 -75.
Composition. Pure antimony, often with a little silver,
iron, or arsenic. B. B. on charcoal fuses easily and passes
off in white fumes.
Obs. Occurs in veins of silver and other ores in Dauphiny,
Bohemia, Sweden, the Hartz, and Mexico.
Stibnite. — Gray Antimony. Antimony Sulphide.
Trimetric. In right rhombic prisms, with striated lateral
faces ; / A/=90° 45'. Cleavage in the direction of the shorter
diagonal, highly perfect. Commonly diver-
gent columnar or fibrous. Sometimes massive
granular.
Color and streak lead-gray ; liable to tarn-
ish. Lustre shining. Brittle ; but thin lami-
nae a little flexible. Somewhat sectile. II. =2.
G. =4-5-4 -62.
Composition. Sb2 S3= Sulphur 28-2, anti-
mony 71*8. Fuses readily in the flame of a
candle. B. B. on charcoal it is absorbed, giv-
ing off white fumes and a sulphur odor.
Diff. Distinguished by its extreme fusibility
and its vaporizing before the blowpipe.
Obs. Stibnite occurs in veins with ores of silver, lead,
zinc, or iron, and is often associated with barite, spathic
iron, or quartz. It occurs at Felsobanya and Schemnitz in
Hungary ; at Wolfsberg in the Hartz ; at Braunsdorf near
Freiberg; in Auvergne, Cornwall, Spain, and Borneo.
THE ARSENIC GROUP. 101
In the United States, it has been found sparingly at Car-
mel, Me., Lyme, N. H., and at "Soldier's Delight," Md.,
in the Humboldt mining region, and in the mines of Aurora,
Esmeralda County, Nevada.
This ore affords much of the antimony of commerce. By
simple fusion, the crude antimony of the shops is obtained,,
from which pure antimony and its pharmaceutical prepara-
tions are made.
Allemontite is an arsenical antimony, Sba As3, from Allemont, and
also from Bohemia and the Hartz.
Valentinite. White antimony in white, grayish, or reddish rect-
angular crystals, with perfect cleavage, affording a rhombic prism of
130 58'. 'Also in tabular masses, and columnar and granular. H. =
2 '5-3. G. =5'57. Lustre adamantine to pearly. Composition, Sb203
=Oxygen 16-44, antimony 83 56=100.
Senarmontite is the same compound in isometric forms.
Kermesite or red antimony is an antimony oxide and sulphide, in
red tufts of capillary crystals. Lustre adamantine. From Hungary,
Dauphiny, Saxony, and the Hartz.
Cei-vantite. An oxide of antimony, Sb2 O4, resulting from the de-
composition of stibnite.
Livingstonite. Like stibnite, but contains 14 per cent, of mercury
and has a red streak. From Mexico.
Native Bismuth.
Ehombohedral ; R A E— 87° 40'. Cleavage rhombohedral,
perfect. Generally massive, with distinct cleavage ; some-
times granular.
Color and streak silver white, with a slight tinge of red.
Subject to tarnish. Brittle when cold, but somewhat mal-
leable when heated. H. =2-2-5. G.=9'7-9-8. Fuses at
a temperature of*£76° F.
Composition. Pure bismuth, with sometimes a trace of
arsenic, sulphur or tellurium. B.B. on charcoal vaporizes,
and leaves a yellow coating on the coal, paler on cooling.
Obs. Native Bismuth is abundant with ores of silver and
cobalt in Saxony and Bohemia, and occurs also in Cornwall
and Cumberland, England. At Schneeberg, it forms arbo-
rescent delineations in brown jasper. Occurs also in Nor-
way, Sweden, Chili and Bolivia ; also at the Balhannah
mine, in S. Australia, with copper ore and gold.
In the United States, it has been found at Lane's and
Booth's mine, Monroe, where it occurs with tungsten, galenite
and pyrite ; also at Brewer's mine, in Chesterfield district,
South Carolina ; and in Colorado.
102 DESCRIPTIONS OP MINERALS.
Bismuthinite. A bismuth sulphide, Bia S3, in acicular crystals of a
lead-gray color.
G-uanajuatite. A bismuth selenide, from Guanajuato, Mexico, called
also frenzelite. Silaonite is a selenide from the same locality, of a
lead-gray color.
Bismite. Bismuth ochre, an impure oxide, grayish, to greenish and
yellowish white, and massive or earthy, found with native bismuth.
Tetradymite. — Bismuth Telluride.
Hexagonal ; R A R = Sl° 2'. Crystals often tubular, with
a very perfect basal cleavage. Also massive, and foliated
or granular. Laminae flexible, and soil paper. Lustre
splendent metallic. Color pale steel-gray, a little sectile.
H.= 1-5—2. G.=7;2— 7 -9.
Composition. Consists of bismuth and tellurium, with some-
times sulphur and selenium, affording for the most part the
formula Bi2 (Te, S)3. A variety from Dahlonega, Georgia,
gave Tellurium 48-1, bismuth 51'9 = Bi,Te3 ; G. = 7>642.
Joseite is a bismuth telluride from Brazil, in which half the
bismuth is replaced by sulphur ; and WeJirlite is another
containing sulphur, from Deutsch Pilsen, Hungary, having
8=8-44.
Obs. Found with gold in Virginia, North Carolina, and
Georgia ; Highland, Montana Territory ; Red Cloud Mine,
Colorado ; Montgomery Mine, Arizona.
General Remarks. — The metal bismuth is obtained mostly from
native bismuth. Besides the above ores, there are also others in which
the metal is combined with silver, lead, and cobalt (pp. 116, 166) ;
and a carbonate of bismuth, which occurs rarely in connection with
native bismuth or the ores of the metal, as a result of oxidation ; also
a silicate.
IV. CARBON GROUP.
The Carbon group in chemistry comprises carbon and
silicon, in which the formula for the most prominent oxide
is R 02. Only carbon occurs native.
Carbon occurs crystallized in the diamond and graphite ;
as oxides, in carbon oxide, and carbon dioxide (ordinarily
called carbonic acid); combined with hydrogen, or hydrogen
and oxygen, in bitumen, mineral oils, amber, and a num-
ber of native mineral resins, and mineral wax; and as the
chief constituent of mineral coal, in which it is combined
CARBON GROUP. 103
with more or less of hydrogen and oxygen and usually some
nitrogen.
Diamond.
Isometric. In octahedrons, dodecahedrons and more com-
plex forms. Faces often curved, as in the figures. Cleavage
octahedral ; perfect.
Color white, or colorless ; also yellowish, red, orange,
green, blue, brown or black. Lustre adamantine. Trans-
parent; translucent when dark -colored. H. =10. Q.=
3.48—3-55.
Composition. Pure carbon. It burns and is consumed at
a high temperature, producing carbonic acid gas. Exhibits
vitreous electricity when rubbed. Some specimens exposed
to the sun for a while, give out light when carried to a dark
place. Strongly refracts and disperses light.
Diff. Diamonds are distinguished by their superior hard-
ness ; their brilliant reflection of light and adamantine
lustre, their vitreous electricity when rubbed, which is not
afforded by other gems unless they are polished ; and, by the
practiced ear, by means of the sound when rubbed together,
Obs. The coarse diamonds, unfit for jewelry, are called
tort, and the kind in black pebbles, or masses, from Brazil,
carbonado. The latter occur sometimes in pieces 1,000
carats in weight ; they have G. =3 to 3 '42. Another kind is
much like anthracite, Gr. = 1 -66, although as hard as diamond
crystals ; it is in globules or mammillary masses, often partly
made up of concentric layers.
Diamonds occur in India, in the district between Golconda
and Masulipatam, and near Parma, in Bundelcund, where
some of the largest have been found ; also on the Mahanuddy,
104 DESCRIPTIONS OF MINERALS.
in Ellore. In Borneo, they are obtained on the west side of
the Ratoos Mountain, with gold and platina. The Brazilian
mines were first discovered in 1728, in the district of Serra
do Erio, to the north of Rio de Janeiro ; the most celebrated
are on the river Jeqnitinhonha, which is called the Diamond
River, and the Rio Pardo ; seventy to seventy-five thousand
carats are exported annually from these regions. In the
Urals of Russia they had not been detected till July, 1829,
when Humboldt and Rose were on their journey to Siberia.
The river Gunil, in the province of Constantine, in Africa,
is reported to have afforded some diamonds.
In South Africa, where they were first discovered in 1867,
they occur in the gravel of the Vaal River, and in the
Orange River country. The value of the diamonds obtained
up to November, 1875, has been estimated as exceeding
60,000,000 of dollars.
In the United States, the diamond has been met with in
Rutherford County, North Carolina; Hall County, Georgia ;
also Franklin County, North Carolina ; in Manchester,
opposite Richmond, Virginia ; also in Cherokee Ravine,
Butte County, Forest Hill in El Dorado County (one weigh-
ing nearly 5 -62 grains), Fiddletown in Amador County, and
in Nevada County, California; and on the coast of Southern
Oregon. It has been reported from Idaho.
The original rock in Brazil appears to be either a kind of
laminated granular quartz, called itacolumyte ; or a ferru-
ginous quartzose conglomerate. The itacolumyte occurs in
the Urals, and diamonds have been found in it ; and it is
also abundant in Georgia and North Carolina. In India,
the rock is a quartzose conglomerate. The origin of the
diamond has been a subject of speculation, and it is the
prevalent opinion that the carbon, like that of coal and
mineral oil, is of vegetable or animal origin. Some crystals
have been found with black uncrystallized particles or seams
within, looking like coal ; and this fact has been supposed
to indicate such an origin.
Diamonds, with few exceptions, are obtained from allu-
vial Avashings. In Brazil, the sands and pebbles of the
diamond rivers and brooks (the waters of which are drawn
off in the dry season to allow of the work) are collected and
washed under a shed, by a stream of water passing through
a succession of boxes. A washer stands by each box, and
inspectors are stationed at intervals.
CARBON GROUP. 105
Diamonds are valued according to their color, transpa-
rency and size. The rose diamond is more valuable than
the pure white, owing to the great beauty of its color and
its rarity. The green diamond is much esteemed on account
of its color. The blue is prized only for its rarity, as the
color is seldom pure. The black diamond, which is uncom-
monly rare and without beauty, is highly prized by collec-
tors. The brown, gray and yellow varieties are of much less
value than the pure white or limpid diamond.
The largest diamond of which we have any knowledge is
mentioned by Tavernier, as in the possession of the Great
Mogul. It weighed originally 900 carats, or 2,769-3 grains,
but was reduced by cutting to 861 grains. It has the form
and size of half of a hen's egg. It was found in 1550, in
the mine of Colone. The diamond which formed the eye
of a Braminican idol, and was purchased by the Empress
Catherine II. of Russia from a French grenadier who had
stolen it, weighs 194| carats, and is as large as a pigeon's
egg. The Austrian crown has a diamond weighing 139 \
carats. The Pitt or Regent diamond is of less size, it weighing
but 136-25 carats, or 419£ grains ; but on account of its un-
blemished transparency and color, it is considered the most
splendid of Indian diamonds. It was sold to the Duke of
Orleans by Mr. Pitt, an English gentleman, who was gover-
nor of Beiicolen, in Sumatra, for £130,000. It is cut in the
form of a brilliant, and is estimated at £125,000. The
Rajah of Mattan has in his possession a diamond from Bor-
neo, weighing 367 carats. The Koh-i-noor, on its arrival
in England, weighed 186-016 carats.* It is said by Taver-
nier to have originally weighed 787-J- carats. It has since
been recut and reduced one-third in weight.
In the Dresden Treasury there is an emerald green dia-
mond, weighing 31J carats. The Hope diamond, weighing
44jL carats, has a beautiful sapphire-blue color.
The diamonds of Brazil are seldom large. Maure men-
tions one of 120 carats, but they rarely exceed 18 or 20.
One weighing 254^ carats, called the "Star of the SoutJt,"
was found in 1854.
Of South African diamonds, the " Schreiner" weighed,
* A carat is a conventional weight, and is divided into 4 grains, which are a little
ighter than 4 grains troy ; 74 1-1 <> carat grains nre equal to 72 troy grains. The term
carat is derived from the name of a bean in Africa, which, in a dried state, has long
been used in that country for weighing gold. These beans were early carried to
India, and were employed there for weighing diamonds.
106 DESCRIPTIONS OF MINERALS.
in its rough state, 308 carats ; and the " Stewart," which has
a light straw color, 288-35 carats. The diamonds of South
Africa are mostly "off col or; "about 10 per cent, are of
first quality ; 15/2d ; 20, 3d ; and 55 per cent, are bort (W.
J. Morton). The "Star of South Africa," of pure water,
weighed 83-5 carats. Some crystals crack to pieces after
being exposed to the air awhile.
The diamond is cut by taking advantage of its cleavage, and
also by abrasion with its own powder. The flaws are some-
times removed by cleaving it. Afterwards the crystal is fixed
to the end of a stick of soft solder when the solder is in a
half-melted state, leaving the part projecting which is to be
cut. A circular plate of soft iron is then charged with the
powder of the diamond, and this, by its revolution, grinds
and polishes the stone. By changing the position, other
facets are added in succession till the required form is ob-
tained. Diamonds were first cut in Europe, in 1456, by Louis
Berquen, a citizen of Bruges ; but in China and India, the art
of cutting appears to have been known at a very early period.
By the above process, diamonds are cut into brilliant, rose
and table diamonds. The brilliant has a crown or upper
part, consisting of a large central eight-sided facet, and a
series of facets around it ; and a collet, or lower part, of py-
ramidal shapes, consisting of a series of facets, with a mailer
series near the base of the crown. The depth of a brilliant
is nearly equal to its breadth, and it therefore requires a
thick stone. Thinner stones, in proportion to the breadth,
are cut into rose and table diamonds. The surface of the
rose diamond consists of a central eight-sided facet of small
size, eight triangles, one corresponding to each side of the
table, eight trapeziums next, and then a series of sixteen tri-
angles. The collet side consists of a minute central octagon,
surrounded by eight trapeziums, corresponding to the angles
of the octagon, each of which trapeziums is subdivided by a
salient angle into one irregular pentagon and two triangles.
The table is the least beautiful mode of cutting, and is used
for such fragments as are quite thin in proportion to the
breadth. It has a square central facet, surrounded by two
or more series of four-sided facets, corresponding to the sides
of the square.
Diamonds have also been cut with figures upon them. As
early as 1500, Charadossa cut the figure of one of the Fathers
of the church on a diamond, for Pope Julius II.
CARBON GROUP. 107
Diamonds are employed for cutting glass; and for this
purpose only the natural edges of crystals can be used, and
those with curved faces are much the best. Diamond dust
is used to charge metal plates of various kinds for jewelers,
lapidaries and others. Those diamonds that are unfit for
working, are sold for various purposes, under the name of
lort. Drills are made of small splinters of bort, and used
for drilling other gems, and also for piercing holes in artifi-
cial teeth and vitreous substances generally ; and, others of
iron set with a few diamonds, for drilling rocks.
Graphite. — Plumbago.
Hexagonal. Sometimes in six-sided prisms or tables with
a transversely foliated structure. Usually foliated, and mas-
sive ; also granular and compact.
Lustre metallic, and color iron-black to dark steel-gray.
Thin lamina flexible. R. = l-2. G.=2'25-2-27. Sofia
paper, and feels greasy.
Composition. Commonly 95 to 99 per cent, of carbon.
B.B. infusible, both alone and with reagents; not acted
upon by acids.
Diff. Kesembles molybdenite, but differs in being unaf-
fected by the blowpipe and acids. The same characters dis-
tinguish the granular varieties from any metallic ores they
resemble.
Obs. Graphite (called also black lead] is found in crys-
talline rocks, especially in gneiss, mica schist and granular
limestone ; also in granite and argillyte. Its principal Eng-
lish locality at Borrowdale, in Cumberland, is now nearly
exhausted.
In the United States graphite occurs in large masses in
veins in gneiss at Sturbridge, Mass. It is also found in
North Brookfield, Brimfield and Hinsdale, Mass. ; abundant
at Roger's Rock, near Ticonderoga ; near Fishkill Landing in
Dutehess County ; at Rossie, in St. Lawrence County, and
near Amity, in Orange County, N. Y. ; at Greenville, N. C. ;
in Cornwall, near the Housatonic, and in Ashford, Ct. ; near
Attleboro, in Bucks County, Penn. ; in Brandon, Vermont ;
in Wake, North Carolina ; on Tyger River, and at Spartan-
burg, near the Cowpens Furnace, South Carolina ; also
abundantly and of excellent quality in Canada, in Bucking'
ham, Fitzroy and Grenville.
108 DESCRIPTIONS OF MINERALS.
For the manufacture of the best pencils the granular
graphite was thought necessary, and hence the former great
value of the Borrowdale mine, where the texture was pecu-
liarly fine and firm. But now the graphite is ground up,
and then compressed under heavy pressure, and thus the
fine texture and firmness required may be obtained with any
pure graphite. At Sturbridge, Mass., it is rather coarsely
granular and foliated, and has been extensively worked.
The mines of Ticonderoga and Fishkill Landing, N. Y. ;
of Brandon, Vt. ; and of Wake, North Carolina, are also
worked ; and that of Ash ford, Ct., formerly afforded a large
amount of graphite, though now the works are suspended.
Graphite is extensively employed for diminishing the
friction of machinery ; also for the manufacture of crucibles
and furnaces ; and as awash for giving a gloss to iron stoves
and railings. For crucibles it is mixed with half its weight
of clay.
Carbonic Acid.
Carbonic acid — carbon dioxide of existing chemistry — is
the gas that gives briskness to the Saratoga and many other
mineral waters, and to artificial soda water. Its taste is
slightly pungent. It extinguishes combustion and destroys
life.
Composition. C 0,= Oxygen 72-35, carbon 27 -65 = 100.
This gas is contained in the atmosphere, constituting
about 4 parts, by volume, in 10,000 parts ; and it is present
in minute quantities in the waters of the ocean and land. It
is given out by animals in respiration, and is one of the re-
sults of animal and vegetable decomposition ; and from this
source the waters derive much of their carbonic acid. This
gas is the choke-damp of mines, where it is often the occasion
of the destruction of life. It is often present also in wells.
Carbon dioxide (or carbonic acid) is given out by lime-
stone (or calcium carbonate) when it is heated ; and quick-
lime is limestone from which C 0? has been expelled by heat,
a process carried on usually in a limekiln. It is also driven
from limestone by the action of sulphuric acid, with the for-
mation of gypsum (a hydrous calcium sulphate), or anhy-
drite (an anhydrous calcium sulphate). These processes are
often carried on in volcanoes, and hence carbonic acid gas is
common in some volcanic regions. The Grotto del Cane
(Dog Cave) at the Solfatara near Naples; is a small cavern
109
filled to the level of the entrance with this gas. It is a com-
mon amusement for the traveler to witness its effect upon a
dog kept for that purpose-. He is held in the gas awhile and
is then thrown out apparently lifeless ; in a few minutes he
recovers himself, picks up his reward, a bit of meat, and runs
off as lively as ever. If continued in the carbonic acid gas a
short time longer, life would have been extinct.
Carbonic acid, under high pressure, becomes a liquid, and,
with pressure and cold, a white snow-like solid. In the liquid
state it is often found in microscopic globules in the inte-
rior of crystallized quartz, topaz, and some other mineials ;
and when this is true, calcite (calcium carbonate) is often
present in the same or an adjoining rock.
Besides the calcium carbonate in nature, there are also
carbonates of ammonium, sodium, barium, strontium, mag-
nesium, iron, manganese, zinc, copper, lead, nickel, cobalt,
bismuth, uranium, cerium, and lanthanum.
II. MINERALS CONSISTING OF THE BASIC
ELEMENTS WITH OR WITHOUT ACIDIC—
THE SILICATES EXCLUDED.
I. GOLD.
Gold occurs mostly native, being either pure, or alloyed
with silver and other metals. It is occasionally found min-
eralized by tellurium, making part of the valuable minerals
Sylvanite, Nagyagite and Petzite. It occurs often dissemi-
nated through pyrite and galenite in auriferous regions,
rendering these minerals valuable sources of gold.
Native Gold.
Isometric. In octahedrons, dodecahedrons ; without cleav-
age. Also in arborescent forms, consisting of strings of
crystals, filiform, reticulated, in grains, thin laminae and
masses.
Color various shades of gold-yellow, becoming pale from
alloy with silver ; occasionally nearly silver-white from
the silver present. Eminently ductile and malleable. H. =
£•5-3. G. =12-20, varying according to the metals alloyed
with the gold. Fuses at 2,016° F. (1,102° C.)
110
DESCRIPTIONS OF MIN..KALS.
Composition. Native gold usually contains silver, and in
very various proportions ; and the color becomes paler with
the increase of silver. The finest • native gold from Russia
yielded gold 98-96, silver 0-16, copper 0-35, iron 0-05 ;
*G. =19-099. A gold from Marmato afforded only 73-45 per
cent, of gold, with 26-48 per cent, of silver; Gr.=12-666.
This last is in the proportion of 3 of gold to 2 of silver. The
following proportions also have been observed : 3J to 2 ; 5
to 2 ; 3 to 1 ; 4 to 1, and this the most common ; 6 to 1 is
also of frequent occurrence. Average of California native
gold is 88 per cent, gold, and the range mostly between 87
and 89; the range of the Canadian, mostly between 85 and
90 ; of Australian, between 90 and 96 per cent., and the
average 93£. The Chilian gold afforded Domeyko 84 to 96
per cent, of gold, and 15 to 3 per cent, of silver. The more
argentiferous gold has been called Electrum; the atomic pro-
portion of 1 : 1 between the gold and silver corresponds to
35-5 per cent, of silver, and that of 2 : 1, to 21'6 per cent.
Copper is occasionally found in alloy with gold, and some-
times also iron, bismuth, palladium and rhodium. A rhodium-
gold from Mexico gave the specific gravity 15 '5-1 6 '8, and
contained 34 to 43 per cent, of rhodium. A bismuth gold
has been called Maldonite.
Diff. Iron and copper pyrites are often mistaken for gold
by those inexperienced in ores ; but these are brittle minerals,
while gold may be cut in slices, and flattens under a hammer.
Pyrite is too hard to yield at all to a knife, and copper
pyrites affords a dull "greenish powder. Moreover pyrite
gives off sulphur when strongly heated, while gold melts
without odor.
GOLD. HI
Obs. Native gold is mostly confined to quartz, intersect-
ing in veins, or interlaminated with, subcrystalline slaty or
schistose rocks, especially hydromica and chloritic slates. It
occurs sparingly iu similar or other veins in granite, gneiss,
or mica slate. It has also been found in traces, according
to J. J. Stevenson, in the trachytes of Colorado, and in
Silurian and Carboniferous quartzytes.
The quartz intersects the slaty rocks in veins and lies in
thick seams between their layers. It is frequently cellular
for a considerable distance from the surface owing to the
alteration and removal of pyrite, galena, or other metallic
ores that may be accompaniments of the gold, and the
cavities are usually rusty with oxide of iron, and sometimes
contain particles of sulphur left by the decomposing pyrite,
and also strings or laminae of gold. The rock in this cav-
ernous state is rather easily quarried out ; buc deep below,
where the minerals are not removed by decomposition, mining
is far more difficult.
Pyrite itself is nearly as hard as quartz, when unaltered,
and readily strikes fire with a steel. This pyrite is often
very abundant, and contains throughout it considerable
gold ; but the gold is so finely distributed, that little of it
can be removed by the ordinary process of crushing and
amalgamation ; nature's way consists in decomposing the
pyrite and thereby making it drop its load. The galenite
of a gold region is also usually auriferous.
Gold sometimes occurs in the slate rocks adjoining the
veins, though mostly confined to the latter. Auriferous
quartz often contains no gold visible to the naked eye.
But while quartz veins are to a large extent the actual
repositories of the gold in its native state, a very large
part of the gold derived from auriferous regions has come
from the sand and gravel beds, in which it occurs in flat-
tened grains, and sometimes in lumps and nuggets. By dif-
ferent methods — erosion by running waters, movements of
glaciers, natural decomposition, and other disintegrating
action — the gold-bearing rocks have been extensively re-
duced to earth and stones, and this loose material has been
distributed along the river courses, making vast alluvial or
diluvial gravelly formations. From these gravels the gold
is obtained by simple washing, thus taking advantage of the
high specific gravity of gold. Streams are carried in aque-
ducts and thrown in great jets against the gravel bluffs to
112 DESCRIPTIONS OP MINERALS.
reduce the material to loose earth and prepare it for further
washing by the same water in sluices arranged for the pur-
pose.
The minerals most common in gold regions are platinum,
iridosmine, magnetite, pyrite, galenite, ilmenite, chalco-
pyrite, blende, tetradymite, zircon, rutile, barite ; also in
some cases wolfram, scheelite, brookite, monazite and dia-
mond. Platinum and iridosmine accompany the gold of
the Urals, Brazil and California ; and diamonds are found
in the gold region of Brazil, and occasionally in the Urals
and United States.
Gold is widely distributed over the globe. In AMERICA,
it occurs in Brazil (where formerly a greater part of that
used was obtained) along the chain of mountains which
runs nearly parallel with the coast, especially near Villa
Rica, and in the province of Minas Geraes ; in New Granada,
at Antioquia, Choco and Giron ; in Chili ; sparingly in Peru
and Mexico ; in Arizona ; in the Coast Range, and, much
more abundantly, in the Sierra Nevada, California ; in
Oregon, British Columbia and Alaska ; in New Mexico,
Colorado, and Wyoming, and other parts of the Rocky
Mountain region ; in the Appalachians from Virginia to
Georgia, a region that formerly produced annually nearly a
million of dollars ; very sparingly in Vermont, New Hamp-
shire, and other New England States ; in Nova Scotia ; in
Beauce County, Canada ; also, north of Lake Superior ;
and in the gravel of Illinois and Indiana.
In EUEOPE, it occurs sparingly in Cornwall and Devon,
England ; North Wales, Scotland, and Ireland, formerly in
the County of Wicklow, where a nugget of 22 ounces was
found ; and in France, very sparingly in the Department of
Isere ; in the sands of the Rhine, the Reuss, and the Aar ;
in Tyrol and Salzburg ; on the southern slope of the Pen-
nine Alps, from the Simplon and Monte Rosa to the Valley
of Aosta, Northern Piedmont, where nearly G,000 ounces
were obtained in 1867 ; more abundantly in Hungary, at
Konigsberg, Schemnitz and Felsobanya, and in Transyl-
vania, at Kapnik, Vorospatak and Offenbanya ; in Spain,,
formerly worked in Asturias ; in Sweden, at Edelfors.
In the Urals are valuable mines at Beresof, and other
places on the eastern or Asiatic flank of this range, and the
comparatively level portions of Siberia ; also in the Altai
Mountains. Also in the Cailas Mountains in Little Thibet •
GOLD. H3
in the rivers of Syria and other parts of Asia
inor ; in Ceylon, China, Japan, Formosa, Java, Sumatra,
Western Borneo, the Philippines, and New Guinea.
In AFRICA, at Kordofan, between Darfour and Abyssinia ;
also south of Sahara, in the western part of Africa, from
the Senegal to Cape Palmas ; also along the coast opposite
Madagascar, between the 22d and 35th degrees south lati-
tude, in the Transvaal Republic. Other regions are Tas-
mania, New Zealand, and New Caledonia.
General Remarks. — The most productive gold regions at the present
time are those of Australia and California.
In Australia the richest mines are those of Victoria and New South
Wales. Victoria yielded, in 1856, 3,000,000 ounces, and in 1875, 1,195,-
250 ; Australia, in 1875, 227,000 ounces. The Australian gold was
first made known to the world in 1851. The localities discovered
were on Summer Hill Creek and the Lewis Pond River (near lat. 33°
N., long. 149°-150 E.), streams which run from the northern flank
of the Coriobolas down to the river Macquarie, a river flowing west-
ward and northward ; it was soon afterward found on the Turon
Eiver, which rises in the Blue Mountains ; and finally a region of
country 1,000 miles in length, north and south, was proved to be
auriferous ; the country is a region of metamorphic rocks, granite and
slates, and in many parts abounds in quartz veins. Queensland and
South Australia, and also Tasmania and New Zealand, afford some
gold.
The first discovery of gold in California was made early in the
spring of 1848, on the American Fork, a tributary to the Sacramento?
near the mouth of which Sutter's establishment was situated. Soon
Feather River, another affluent, 18 or 20 miles north, was also proved
to abound in gold about its upper portions ; and it was not long after
before each stream in succession, north and south, along the western
slope of the Sierra Nevada was found to flow over auriferous sands.
The gold as now developed extends along that chain, through the
whole length of the great north and south valley which holds the
rivers and plains of the Sacramento and San Joaquin. It continues
south nearly to the Tejon pass, in latitude 35°, and north beyond the
Shasta Mountains to the Umpqua, and less productively into Oregon
and Washington Territories, and in British Columbia. Gold also
occurs in some places in the coast range of mountains. Even the
very site of San Francisco has been found to contain traces. North
of Shasta Mountain there are important mines on the Klamath and
the Umpqua, and some of the best on the sea-shore between Gold
Bluff, in 41 30 south of the Klamath (30 miles south of Crescent City)
to the Umpqua. What once was Rogue River is now called Gold River.
In Colorado, gold mines occur in Gil pin County, and much less pro-
ductively in Clear Creek, Park, Boulder, Lake, Summit, and Southern
counties ; and the yield in 1874 amounted to $2,102,487, of which
$1,525,447 were from Gil pin County.
Nevada produced from the Comstock lode (seep. 123), in 1875, gold
*o the amount of about $11, 740, 000, and the rest of Nevada, $2,25G..OOO
114
DESCRIPTIONS OF MINERALS.
making in all nearly $14,000,000 ; and in 1876, the Comstock lode
yielded $18,000,000, and the rest of Nevada about $1,338,000. v
The yield of the United States in gold in the years 1870 to 1876, is
stated as follows in a note dated February 5, 1877, by J. J. Valentine,
in Jones's " Report of the Silver Commission (1877)" :
1870.. $33,750,000
1871 34,398,000
1872 38,109,395
1873 39,206,558
1874 38,466,488
1875 39,968,194
1876 42,886,935
The amount, in 1874, from California is stated at $17,620,000 ; from
Oregon, $609,000 ; Washington, $155,500 ; Idaho, $1,328,430 ; Mon-
tana, $2,850,000 ; Utah, $92,000 ; Arizona, $25,700 ; Colorado, $2,-
102,487 ; Mexico, $84,655 ; British Columbia, $1,636,200.
According to the Report of A. del Mar, in the ' ' Report of the Sil-
ver Commission of 1877," the yield of gold from all America from
1492 to the year 1800, was $1,872,300,000. From 1800 to 1847 inclu-
sive, 48 years, the yield from America, Europe, and Africa is stated at
$42i),200,000 ; and from 1848 to 1876 inclusive, 29 years, $3,381,500,-
000. The largest annual amount was produced in the year 1856,
in which the yield was $147,600,000 ; and next to this, in 1859, with
$144,900,000 ; as shown in the annexed table, giving the amounts
in millions of dollars :
1848..
1849..
1850..
1851 .
1852..
1853 155-0
1854 1'3;-0
1855 135-0
1856 147-6
1857. . . .133-3
. 67-5
, 87-0
, 93-2
,120-0
193-7
1858 ,
1859
1850.
1881
18I3-3 ,
1833,
1864.
1835
1836
1837.
.144-6
.144-9
.119-3
.113-8
.107-8
.107-0
.113-0
.130-7
.122-2
,114-0
1888.
1869.
1870.
1871.
187-3.
1873.
1874
1875.
1876.
..109-7
..106-2
..106-9
. 1070
.. 99-6
.. 97-2
.. 90-8
.. 97-5
. 90 0
The total amount for these years is $3,381,500,000 The following
table is taken from a Report to the British House of Commons in 187(
— the amount for the United States only being corrected :
Russia.
United
States.
Mexico and
South
America.
Australia.
Other
Countries.
Total.
1850 .
$16,950,000
$27,500,000
1855.. .
1860 . .
1865.. .
1870.. .
1875 .
14,200,000
15,265,000
16,135,000
22.070,000
20,000,000
73.700,000
46,000,000
53,225,000
33,750,000
40,000,000
$5,000,000
4,500,000
4,000,000
2,500,000
3,750,000
$60.325,000
52,500,000
44,100,000
29,150,000
28,750,000
$2,500,000
2.500,000
2,500,000
2,500,000
2,500,000
$155,725.000
1-20, '.65,0(10
119,960,000
89,970,000
95,000,000
GOLD. 115
Masses of gold of considerable size have been found in North Caro-
lina. The largest was discovered in Cabarrus County ; it weighed
28 pounds avoirdupois (" steel-yard weight," equals 37 pounds troy),
and was 8 or 9 inches long, by 4 or 5 broad, and about an inch thick.
In Paraguay, pieces from 1 to 50 pounds weight were taken from a
mass of rock which fell from one of the highest mountains.
The largest masses of gold yet discovered have been found in aurife-
rous gravel. The " Blanch Barkley Nugget," found in South Austra-
lia, weighed 140 pounds, and only six ounces of it were gangue ; and
one still larger, the " Welcome Nugget," from Victoria, weighed
2,195 ounces, or nearly 183 pounds, and yielded £8,376 10s. M. sterling
of gold. Two others from Victoria weighed 1,021, and 1,105 ounces.
In Russia, a mass was found in 1842, near Miask, weighing 90 pounds
troy ; another of 27 pounds, and several of 10 pounds have been found
in the Urals. The largest mass yet reported from California weighed
20 pounds. A remarkably beautiful mass, consisting of a congeries of
crystals, weighing 201 ounces (value $4,000), was found in 1805, seven
miles from Georgetown, in El Dorado County.
The origin of gold veins, or rather of the gold in the veins, is little
understood. The rocks, as has been stated, are metamorphic slates
that have been crystallized by heat ; and they are the hydromica,
chloritic, and argillaceous, that have been but imperfectly crystal-
lized, rather than the mica schist and gneiss, which are well crystal-
lized ; and the veins of quartz which contain the gold, occupy fissures
through the slates, and openings among the layers, which must have
been made when the metamorphic changes or crystallization took
place. It was a period, for each gold region, of long-continued heat
(occupying, probably, a prolonged age), and also of vast upliftings and
disturbances of the beds ; for the beds are tilted at various angles,
and the veins show where were the fractures of the layers, or the sep-
arations and gapings of the tortured strata. The heat appears not to
have been of the intensity required for the better crystallization of the
more perfectly crystalline schists. The quartz veins could not have
been filled from below, by injection ; they must have been filled
either laterally, or from above. In all such conditions of upturning
and metamorphism, the moisture present would have become intensely
heated, and hence have had great dissolving and decomposing power ;
it would have taken up silica with alkalies from the rocks (as happens
in all Geyser regions), along with whatever other mineral substances
were capable of solution or removal ; and the vapor, thus laden,
would have filled all open spaces, there to make depositions of the
silica and ether ingredients it contained. These mineral ingredients
would have been derived either from the rock adjoining the veins or
opened spaces, or from depths below through ascending vapors. By
one or both of these means, the quartz must have received its gold,
pyrite, and ores of lead, copper and other materials— all having been
carried into the open cavities at the same time with the silica or
quartz. The pyrite of the vein is usually auriferous, showing that it
was crystallized under the same circumstances that attended the de-
positing of the gold in strings, crystals, and grains ; and the same is
often true of the galena.
Calavcrite is a bronze-yellow gold telluride. AuTe4= Tellurium
LI 6 DESCRIPTIONS OF MINERALS.
55'5, gold 44-5=100, with a little silver, occurring massive at the Stan,
islaus Mine, California, and the Red Cloud Mine, Colorado, and also
the Keystone and Mountain Lion mines, in the Magnolia District.
Krennerite is another gold telluride.
Sylvanite, called also Graphic tellurium, is a telluride of gold and
silver, also containing sometimes antimony and more or less lead (see
p. 118).
Nagyagite is a telluride of lead containing 9 to 13 per cent, of gold
(see p. 149).
Petzite is a telluride of silver, allied to Hessite (p. 118^, containing
gold ; a specimen from Golden Rule Mine, Colorado, contained 25-60
per cent, according to Genth.
II. SILVER.
Silver occurs native, and alloyed, or combined with gold ;
also combined with sulphur, selenium, tellurium, arsenic,
antimony, bismuth, chlorine, bromine, or iodine ; but nevei
as an oxide, carbonate, sulphate, or phosphate.
Native Silver.
Isometric. In octahedrons and other forms. No cleavage
apparent. Occurs often in filiform and arborescent shapes,
the threads having a crystalline character ; also in laminae,
and massive.
Color and streak silver-white and shining. Often black
externally from tarnish. Sectile. Malleable. H. =2-5-3.
G.= 10 -1-11-1.
Composition. Native silver is usually an alloy of silver
and copper, the latter ingredient often amounting to 10 per
cent. It is also alloyed with gold, as mentioned under that
metal. A bismuth silver from Copiapo, S. A., contained 16
per cent, of bismuth.
B.B. fuses easily to a silver- white globule. Dissolves in
nitric acid, from which it is precipitated as white chloride
on adding hydrochloric acid. A clean plate of copper im-
mersed in the nitric solution becomes coated with silver.
Diff. Distinguished by being malleable ; from bismuth
and other white native metals by affording no fumes before
the blowpipe ; by affording a precipitate with hydrochloric
acid which becomes black on exposure.
Obs. Native silver occurs in masses and string-like ar-
borescences, penetrating the gangue, or its minerals, in
SILVER. 117
various silver mines. It is also found mixed with native
copper.
The mines of Norway, at Kongsberg, formerly afforded mag-
nificent specimens of native silver, but they are now mostly
under water. One specimen from this locality, at Copenha-
gen, weighs five hundred pounds ; and two other masses
have been found weighing 238 and 436 pounds. Other Eu-
ropean localities are in Saxony, Bohemia, the Hartz, Hun-
gary, Dauphiny. Peru and Mexico also alford native silver.
A Mexican specimen from Batopilas, weighed when obtained
403 pounds ; and one from Southern Peru (mines of Huan-
tajaya) weighed over 8 cwt. Arizona is reported to have
produced one mass weighing 2,700 pounds. In the United
States, in the Lake Superior region, the silver generally pen-
etrates the copper in masses and strings, and is very nearly
pure, notwithstanding the copper about it. Large masses
occur at the Idaho Silver Mine, called the Poor Man's Lode ;
and in strings it is occasionally found in the mines of Ne-
vada, California, and Colorado.
Much of the galena of the world contains a very small per-
centage of silver ; that of Monroe, Conn., yields nearly 3
per cent.
Native silver has also been observed near the Sing Sing
state prison ; at the Bridgewater copper mines, N. J. ; and
in handsome specimens at King's Mine, Davidson County,
North Carolina.
Native Amalgam is a compound of silver and mercury. The com-
pounds AgHg = Silver 35*1, mercury 64'9, or Ag2 H3 = Silver 26'5,
mercury 73 5, are included. Another from Chili having the formula
Ag12Hgand containing 86 '6 per cent, of silver has been called AT-
querite; and still another Ag]8 Hg, Kongsbergite.
Argentite. — Silver Glance. Sulphuret of Silver.
Isometric. In dodecahedrons more or less modified.
Cleavage sometimes apparent parallel to the faces of the
dodecahedron. Also reticulated and massive.
Lustre metallic. Color and streak blackish lead-gray ;
streak shining. Verysectile. H.= 2-2'5. G.-7-19-
7-4.
Composition. When pure, Ag2S = Sulphur 12-9, silver
87'1. B.B. on charcoal in O.F. it intumesces, gives oif the
odor of sulphur, and finally affords a globule of silver.
Diff. Resembles some ores of copper and lead, and other
118 DESCRIPTIONS OF MINERALS.
ores of silver, but is distinguished by being easily cut, like
lead, with a knife ; and also by affording a globule of silver
on charcoal, by heat alone. Its specific gravity is much
higher than that of any copper ores.
Obs. This important ore of silver occurs in Europe prin-
cipally at Annaberg, Joachimstahl, and other mines of the
Erzgebirge ; at Schemnitz, and Kremnitz, in Hungary, and
at Freiberg in Saxony. It is a common ore at the Mexican
silver mines, and also in the mines of South America. It
occurs in Arizona, with chalcocite, at the Heintzelman Mine,
and in Nevada.
A mass of "sulphuret of silver" is stated by Troost to-
have been found in Sparta, Tennessee.
Acanthite is a trimetric sulphide of silver, Ag2S, from
Joachimstahl ; and Daleminzite, another, from near Frei-
berg.
Stromeyerite. A steel-gray sulphide of silver and copper, Ag2S
+ Ciij S = Sulphur 15-7, silver 53'1, copper 31-2 = 100. G.= fr26.
B.B. it fuses and gives in the open tube an odor of sulphur ; but a
silver globule is not obtained except by cupellation with lead. From
Peru, Silesia, Chili, Siberia, and Arizona.
Sternbergite. A sulphide of silver and iron containing 33 per cent,
of silver. It is a highly foliated ore resembling graphite, and like it
leaving a tracing on paper ; the thin laminae are flexible ; color pinch-
beck brown ; streak black. From Joachimstahl and Johanngeorgen-
stadt.
Naumannite. A selenide of silver and lead in iron -black cubes and
massive ; G. =8 ; contains 73 per cent, of silver. From the Hartz.
Hessite. A telluride of silver, Ag2 Te= Tellurium 37-2, silver 62-8 =
100. Color between lead-gray and steel-gray. Sectile. G. =8*3 — 8'6.
B.B. in the open tube, faint sublimate of tellurous acid; on char-
coal with soda a silver globule. From the Altai ; at Nagyag and
Retzbanya ; Coquimbo, Chili ; Calaveras Co. , Cal. ; Red Cloud Mine,
Colorado ; Kearsarge Mine, Dry Canyon, Utah.
Petzite is a hessite with the silver replaced in part by gold. G. =
8 '7-9 '4. Between steel-gray and iron -black. Variety from Golden
Rule Mine, afforded Genth Tellurium 32 '68, silver 41 '86, gold 25 60=
10014. Occurs at the same localities with hessite.
Tapalpite is a telluride of bismuth and silver from Mexico.
Syfoanite or Graphic Tellurium, A telluride of gold and silver
(Ag, Au) Tea = (if Ag : Au=l : 1) Tellurium 55 '8, gold 28'5, silver 15'7
= 100. Color and streak steel-gray to silver- white, and sometimes nearly
brass-yellow. H.=l'5-2. G.=7'99-8'33. Called graphic because of
a resemblance in the arrangement of the crystals to writing charac-
ters. From Transylvania ; Calaveras Co. , California ; Red Cloud and
Grand View Mines, Colorado.
Eucairite. A selenide of silver and copper, containing 42-45 per
cent, of silver ; color between silver- white and lead-gray ; easily cut
by the knife. . From Sweden and Chili.
SILVER. 119
Dyscrasite, or Antimonicd Silver, consists simply of silver and anti-
mony (78 parts to 22=Ag4 Sb), and has nearly a tin-white color.
G.— 9'4-9'8. B.B. fumes of antimony pass off, leaving finally a
globule of silver. From Wolfach, Wittichen, Andreasberg ; also
Allemont in Dauphiny ; and Bolivia, S. A.
Pyrargyrite.— Ruby Silver. Dark Red Silver Ore.
Ehombohedral. ^72 = 108° 42; E/^i-2 = 129° 39'.
Cleavage parallel to R imperfect. Also massive. Black to
dark cochineal-red, with the streak cochi-
neal-red and lustre splendent metallic-ada-
mantine. H. = 2-2 -5, G. = 5 -7-5 -9.
Composition. Ag3S3Sb (=3 Ag2S + Sb3
S,) = Sulphur 17*7, antimony 22 -5, silver
59-8 = 100.
B. B. fuses very easily ; on charcoal a
white deposit of antimony oxide is deposited,
and with soda a globule of silver is obtained. In an open
tube gives off sulphurous fumes that redden litmus paper.
Diff. Its red streak, and its reactions for antimony and
silver, are distinctive.
Obs. Occurs at Andreasberg ; also in Saxony, Hungary,
Cornwall, Mexico, Chili ; in Nevada at Washoe ; abundant
about Austin, Reese River ; at Poor Man's Lode, Idaho.
Proustite, or Light Red Silver Ore, is a related ore con-
taining arsenic in place of much or all of the antimony.
Composition, Ag3 Ss As = Sulphur 19-4, arsenic 15*1, silver
65-5 = 100. G.=5-4-5-56.
B. B. gives a garlic odor.
Occurs with pyrargyrite at the above-mentioned localities.
Stephanite.— Brittle Silver Ore. Black Silver.
Trimetric. 7A 7=115° 39'. No perfect cleavage. Often
in compound crystals. Also massive. Streak and color
iron-black. II. = 2-2 -5. G. = 6 -27.
Composition. Ag5 S4 Sb ( = 5 Ag2 S + Sb2 S3) = Sulphur
16-2, antimony 15*3°, silver 68*5. B.B. it gives an odor of
sulphur and also fumes of antimony, and yields a dark
metallic globule, from which silver may be obtained by the
addition of soda. Soluble in dilute nitric acid, and the solu-
tion indicates the presence of silver by silvering a plate of
copper.
120 DESCRIPTIONS OP MINERALS.
Obs. It occurs with other silver ores at Freiberg, Schnee-
berg, and Johanngeorgenstadt, in Saxony ; also in Bohe-
mia, and Hungary. It is an abundant ore in Chili, Peru,
and Mexico, and also in Nevada, and at the Comstock Lode,
and at Ophir, and Mexican mines, in the Reese Eiver and
Humboldt, and other regions ; in Colorado and Idaho. It is
sometimes called black
Polybasite is near stephanite in color, specific gravity, and composi-
tion, but contains some arsenic and copper, with 64 to 72*2 per cent, of
silver. The crystals are trimetric, and usually in tabular hexagonal
prisms, without distinct cleavage. G. =6,214. From Freiberg, Przi-
brarn ; Mexico and Chili; the Reese mines in Nevada, and Idaho.
Miargyrite is an antimonial silver sulphide, containing but 36 '5 per
cent, of silver, and having a dark cherry-red streak, though iron-black
in color. B.B. on charcoal gives off fumes of antimony and an odor
of sulphur ; and in the oxidating flame, a globule is left which finally
yields a button of pure silver.
Brongniardite occurs in regular octahedrons and massive, grayish-
black in color, and contains about 25 per cent, of silver, with lead, an-
timony, and sulphur G.=5'95. From Mexico.
Polyargyrite also is isometric, having cubic cleavage, and is from
Wolf ach in Baden. It is near polybasite in composition = 12 Ag2 S +
Sb? S3.
Freieslebenite is a monoclinic antimonial silver-and-lead sulphide, of
a light steel-gray color, with G. =6-G'4. Contains 22 to 24 per cent,
of silver. From Saxony, Transylvania, and Spain.
Pyrostilpnite is another monoclinic silver ore ; its delicate crystals
are grouped like stilbite and have a fire-red color. Contains 62 '3 per
cent, of silver. From Freiberg, Andreasberg, and Przibram.
Cerargyrite. — Horn Silver. Silver Chloride.
Isometric. In cubes, with no distinct cleavage. Also
massive, and rarely columnar ; often incrusting. Color
gray, passing into green and blue ; looks somewhat like horn
or wax, and cuts like it. Lustre resinous, passing into ada-
mantine. Streak shining. Translucent to nearly opaque.
Composition. Ag Cl= Chlorine 24-7, silver 75-3. Fuses
in the flame of a candle, and emits acrid fumes. B.B. af-
fords silver easily on charcoal. The surface of a plate of
iron rubbed with it is silvered.
Obs. A very common ore and extensively worked in the
mines of South America and Mexico, where it occurs with
native silver ; and also abundant in Nevada about Austin,
Lander Co. ; in Idaho at Poor Man's Lode ; occurs also in
Comstock Lode ; and in Arizona ; also at the mines of Sax-
ony, Siberia, Norway, the Hartz, and Cornwall.
SILVER. 121
Bromyrite or Bromic Silver. Silver united with bromine. Ag Br—
Bromine 42 *6, silver 5 7 '4= 100. Occurs with the preceding in Mexico
and Chili.
Embolite. A chlorobromide of silver, resembling the chloride or horn
silver. Color asparagus to olive green. Contains 51 of chloride of sil-
ver, to 49 of bromide. This ore is not less common in Chili than the
chloride. It has also been found in Chihuahua, Mexico.
lodyrite. A silver iodide, Ag I=Iodine 54*0, silver 4G'0=100. It
has a bright yellow color. From Spain, Chili, Mexico, and the Cerro
Colorado Mine in Arizona.
Tocornalite. A silver-and-mercury iodide from Chili.
General Remarks. — The chief sources of the silver of commerce ara
(1) Native silver ; (2) the sulphide, Argcntite (or vitreous silver), com-
mon in Mexico, and also in the Humboldt, lieese River mining dis-
tricts ; four species among the sulpharsenites and sulphantimonites,
viz., (3) Proustite or the light red or ruby silver ore, and (4) Pyrar-
gyrite, or dark red silver ore, both common in Chilian, Peruvian,
and Mexican mines ; (5) Freieslebenite ; (6) Argentiferous tetrahedrite,
which contains sometimes 10 to 30 per cent, of silver, abundant at
some Humboldt County, Nevada, mines, at Colorado silver mines, and
at various Chilian, Bolivian and Mexican mines, as well as in some
silver mines of Europe ; (7) Stephanite or brittle silver ore, common in
Nevada, Colorado, and at the Washoe mines, Western Utah ; (8) the
chloride, called horn-silver or Cerargyrite, common in Chili, Mexico,
Idaho ; (9) the bromide and chlorobromide, Bromyrite and Embo-
lite, common in Chili and Mexico, especially the latter, along with
the rarer iodide ; (10) Argentiferous Galcnite, the lead ore, galenite,
even when containing but 5 ounces of silver to the ton, being profita-
bly worked for its silver. The other ores of silver mentioned beyond
are seldom of great abundance. The most important of them are sil-
ver amalgam or Arquerite, common especially in Chili, and Polybasite.
Silver ores occur in rocks of various ages, in gneiss and allied rocks,
in porphyry, trap, sandstone, limestone, and shales ; and the sand-
stone and shales may be as recent as the Tertiary. The veins often,
intersect trachytic, porphyry, and other eruptive rocks, or the sedi-
mentary formations in the vicinity of such rocks, and have owed their
existence in many cases to the heat, fracturing, and vapors from
below, attending the eruptions.
Silver ores are associated often with ores of lead, zinc, copper, co-
balt, and antimony, and the usual gangue is calcite or quartz, with
frequently fluor spar, pearl spar, or heavy spar.
The silver of South America is derived principally from the horn
silvers, stephanite, ruby silver, vitreous silver ore, and native silver.
Those of Mexico are of nearly the same character. Besides, there are
earthy ores called color ados, and in Peru pacos, which are mostly
earthy oxide of iron, with a little disseminated silver ; they are found
near the surface where the rock has undergone partial decomposition.
The sulphides of lead, iron, and copper of the mining regions, gene-
rally contain silver, and are also worked.
In South America the Chilian mines are on the western slope of the
Cordilleras, and are connected mostly with stratified deposits, of a
shaly, sandstone, or conglomerate character, and their intersections
122 DESCRIPTIONS OF MINERALS.
with porphyries. The chlorides and native amalgams are found in
regions more toward the coast, while the sulphides and ontlmonial
ores abound nearer the Cordilleras. The richest mines are not far dis-
tant from Copiapo, in the mountains north of the valley of Huasco.
The mines of Mt. Chanaryillo, about 16 leagues south of Copiapo,
abound in horn silver, and begin to yield arsenic-sulphides at a depth
of about 500 feet. The mines of Punta Brava, which are nearer the
Cordilleras, afford the arsenical and antiinonial orec.
In Peru, the principal mines are in the districts of Pasco, Chota, and
Huantaya. Those of Pasco are 15,700 feet above the sea, while those
of Huantaya are in a low desert plain, near the port of Yquique, in the
southern part of Peru. The ores afforded are the same as in Chili.
The mines of Huantaya are noted for the large masses of native silver
they have afforded. Silver is obtained in Peru, also, in the districts of
Caxamarca, Pataz, Huamanchuco, and Hualgayoc.
The Potosi mines in Bolivia, occur in a mountain of argillaceous
shale, whose summit is covered by a bed of argillaceous porphyry.
The ore is the ruby silver, and argentite with native silver. The dis-
trict of Caracoles, between Chili and Bolivia, yields much silver.
In Europe the principal mines are those of Spain, the province of
Guadalajara, where the ore is chiefly freieslebenite ; of Kongsberg in
Norway ; of Saxony, chiefly at Freiberg ; the Hartz ; in Austria, Hun-
gary, Transylvania, and the Banat ; and Russia. The mines of Kongs-
berg occur in gneiss and hornblende slate, in a gangue of calc spar.
They were especially rich in native silver.
The mines of Saxony occur mostly in gneiss, in the vicinity of Frei-
berg, Ehrenfriedensdorf, Johanngeorgenstadt, Annaberg, and Schnee-
The ores of the Hartz are mostly argentiferous copper pyrites and
galena, yet the ruby silver, argentite, stephanite, occur, especially at
Andreaskreutz, and the mines of that vicinity. The rock intersected
by the deposits is mostly an argillaceous shale. Calcitc is the usual
gangue, though it is sometimes quartz.
In the Tyrol, Austria, argentite, argentiferous tetrahedrite, and mis-
pickel occur in a gangue of quartz, in argillaceous schist. The Hun-
farian mines at Schemnitz and Kremnitz, occur in syenyte and horn-
lende porphyry, in a gangue of quartz, often with calcite or barite
(heavy spar), and sometimes fluorite. The ores are argentite. tetrahe-
drite, galena, blende, pyritous copper and iron ; and the galena and
copper ores are argentiferous. France produces some silver from ar-
gent'rferous galena at Huelgoet in Brittany, and the mines of Pontgi-
baud, Puy-de-Dome.
The Russian mines are in Kolyvan in the Altai, and Nertchinsk in
the Daouria Mountains, Siberia (east of Lake Baikal). The Daouria
mines afford an argentiferous galena which is worked for its silver ;
it occurs in a crystalline limestone. The silver ores of the Altai occur
in Silurian schists in the vicinity of porphyry, which contain also
gold, copper, and lead ores.
The mines of Mexico are most abundant between 18° and 24° north
latitude, on the back or sides of the Cordilleras, and especially the
west side ; and the principal are those of the districts of Guanaxuato,
Zacatecas, Fresnillo, Sombrerete, Catorce, Oaxaca, Pachuca, Real del
Monte, Batopilas, and Tasco. The veins traverse very different rccka
SILVER.
123
In these regions. The vein of Guanajuato, the most productive in
Mexico, intersects argillaceous and chloritic shale, and porphyry ; it
affords one-forth of all the Mexican silver. The Valeucian mine is
the richest in Guanaxuato. The Pachuca, Real del Monte, and Moro
districts, are near one another. Four great parallel veins tranversv
these districts, through porphyry.
In the United States the chief silver mines are in California, Ne-
vada, Colorado, Utah, Montana, and Idaho. The principal California
mines are in its southeastern counties bordering on Nevada, namely :
Alpine, Mono, and Inyo ; the total yield in 1874, about $1,700;000.
Those of Nevada are the Washoe region, about Virginia City and the
Comstock Lode ; in Lander County, along Reese River Valley, etc.,
the chief town of which is Austin ; Esmeralda County, southeast of
Washoe ; in Eureka County, next east of Lander ; in Lincoln County,
the southeastern of the State ; Huuiboldt County to the north ; White
Pine, Nye and Elko counties, east and southeast of Lander County.
The rocks connected with the veins in Eastern California and Western
Nevada are eruptive rocks, related for the most part to andesyte (in
part, named propylite) and trachyte, with some doleryte. The mines
of Utah, are those of the Big and Little Cottonwood districts (which
include the Emma Mine), the American Fork district, the Parley's
' Park district in the Wahsatch Range north of Big Cottonwood, and
the East Tintic district, in which are the Eureka Hill mines ; those
of Arizona, the Heintzelman, etc.; of Colorado, in the San Juan region;
of Northern Michigan, at the copper mines ; of Canada, at Prince's
Mine, Spar Island, Lake Superior.
For the years previous to 1859 the whole yield of silver from United
States mines is estimated at $1,000,000. The following are the amounts
for the succeeding years, as published in Jones's Senate Report (1877),
those for the years 1871 to 1876, inclusive, being from estimates by
J. J.Valentine.
1859 $100,000
1860 150,000
1861 2,100,000
1862 4,500,000
1883 8,500,000
1864 11,000,000
18()5 11,250,000
1866... 10,000,000
1867 13,550,000
1868 $12,000,000
1869 13,000,000
1870 17,3iO,000
1871 19/286,000
1872 19,924,429
1873 27,483,302
1874 29,699,122
1875 31,635,239
1876 39,292,924
The Comstock Lode contributed to the silver of the world first in 1861.
In 1875 it yielded $14,492,350, and the rest of Nevada $6,717,636^
$21,209,983 ; and in 1876 these amounts were 20,570,078 and 7,462,752
=$28,03 2,830. The $7,462,752 from the " rest of Nevada" in 1876,
were divided, as follows, between its principal mining regions : Lan-
der County, Austin district, $1,187,500 ; Esmeralda County, Columbus
district, $1,624,789 ; Elko County, Cornucopia district, $460,048 ; Eu-
reka County, $1,480,558 ; Lincoln County, Pioche or Ely district,
$790,095 ; Nye County, Tyboe and Reveille districts, $1,450,000.
The yield in 1876 of Utah was $3,351,5^0 ; of Colorado, 3,000,000 ;
of California, 1,800,000; of Arizona, 500,000; of Montana, 800,000;
of Idaho, 300,000 ; of New Mexico, 400,000.
124
DESCRIPTIONS OF MINERALS.
In the " Elements of Metallurgy," of J. Arthur Phillips, the yield
for 1872 is given approximately, as follows :
Lbs. Troy.
52,400
15,000
92,000
Great Britain
Norway and Sweden
Hungary, Transylvania, and the Banat.
Saxony 80,000)
Haruz 27,500^
Rest of Germany 00,500)
Russia
France
Italy
Spain
Peru
Bolivia
Chili ,
Central America
Mexico
United States. .
178,000
50,000
16,500
32,000
100,000
200,000
450,000
800,000
53,000
1,000,000
1,250,000
Total 3,788,900
Mr. Phillips states that the total for the year probably amounted to
4,100,000 Ibs. troy, the value of which is £13,000,000, or $03,000,000.
In the above the amount from the United States is diminished to make
it correspond with the preceding statement for 1872.
The following table gives, in dollars, the estimated value of the
World's production of silver in recent years :
Russia.
United States.
Mexico and
South America
Other Countries.
1855
600,000
30,000,000
10,000,000-40,600,000
1800
1865
1870
1875
650,000
700,000
575,000
500,000
150,000
11,250,000
17,320,000
31,635,000
30,000,000
30,000,000
25,000,000
25,000,000
10,000,000=40,800,000
10,000,000=51,950,000
10,000,000=57,895,000
10,000,000=67,135,000
The total for 1876 is estimated at 76 millions.
The world's production of silver for the period of twenty-six years,
from 1852 to 1877, is estimated at $1,341,800,000 ; for the preceding
twenty-two years— from 1830 to 1851, inclusive— at $600,400,000; for
the preceding thirty years— from 1800 to 1830— at $799,100,000.
Native Platinum.
Isometric : but crystals seldom observed. Usually in flat-
tened or angular grains or irregular masses. Cleavage none.
Color and streak pale or dark steel-gray. Lustre metallic,
PLATINUM. 125
shining. Ductile and malleable. H.=4-4-5. G-. = 16-19;
17-108, small grains ; 17-608, a mass. Often slightly mag-
netic, and some masses will take up iron filings.
Composition* Platinum is usually combined with more
or less of the rare metals iridium, rhodium, palladium, and
osmium, besides copper and iron, which give it a darker
color than belongs to the pure metal, and increase its hard-
ness. A Russian specimen afforded, Platinum 78-9, iri-
dium 5*0, osmium and iridium 1-9, rhodium 0-9, palladium
0-3, copper 0-7, iron 11-0=98'75.
Platinum is soluble in heated aqua regia. It is one of the
most infusible substances known, being wholly unaltered
before the blowpipe. It is very slightly magnetic, and this
quality is increased by the iron it may contain.
Diff. Platinum is at once distinguished by its malleability
and extreme inf visibility.
Obs. Platinum was first detected in 1735 in grains in
the alluvial deposits of Choco and Barbac.oa in New Granada
(now U. States of Colombia), within two miles of the north-
west coast of South America, where it received the name
platina, derived from the word plata, meaning silver. Al-
though before known, an account by Ulloa, a Spanish
traveler in America in 1735, directed attention in Europe,
in 1748, to the metal. It is now obtained in Novita, and
at Santa Rita, and Santa Lucia, Brazil. It has been afforded
most abundantly by the Urals. It occurs also on Borneo ; in
the sands of the Rhine ; in those of the river Jocky, St.
Domingo ; in traces in the United States, in North Carolina ;
at La Francois Beaucc, Canada ; and with gold near Point
Orford, on the coast of Northern California (probably de-
rived, according to W. P. Blake, from serpentine rocks) ; in
British Columbia.
The Ural localities of Nischne Tagilsk and Goroblagodat
have afforded much the larger part of the platinum of com-
merce. It occurs, as elsewhere, in alluvial beds ; but the
courses of platiniferous alluvium have been traced to a great
extent up Mount La Marti ane, which consists of crystalline
rocks, and is the origin of the detritus. One to three pounds
are procured from 3,700 pounds of sand.
Though commonly in small grains, masses of considerable
size have occasionally been found. A mass weighing 1,088
grains was brought by Humboldt from South America and
deposited in the Berlin Museum. Its specific gravity was
126 DESCRIPTIONS OP MINERALS.
18-94. In the year 1822, a mass from Condoto was de-
posited in the Madrid Museum, measuring 2 inches and 4
lines in diameter, and weighing 11,641 grains. A more
remarkable specimen was found in the year 1827 in the
Urals, not far from the Demidoff mines, which weighed 11£
(more accurately, 11-57) pounds troy; and similar masses
are now not uncommon. The largest yet discovered weighed
21 pounds troy ; it is in the Demidoff cabinet.
Russia affords annually about 35 cwt. of platinum, which
is about five times the amount from Brazil, Borneo, Colom-
bia, and St. Domingo. Borneo affords about 500 pounds
per year.
The North Carolina platinum was found with gold in
Rutherford County. It was a single reniform granule, weigh-
ing 2*54 grains. Other instances are reported from the
Southern gold region.
The infusibility of platinum and its resistance to the
action of the air, and moisture, and most chemical agents,
renders it of great value for the construction of chemical
and philosophical apparatus. The large stills employed in
the concentration of sulphuric acid are now made of plati-
num ; but such stills are gilt within, since platinum when
unprotected is acted upon by the acid, and soon becomes
porous. It is also used for crucibles and capsules in chemi-
cal anal}rsis ; for galvanic batteries ; as foil, or worked into
cups or forceps, for supporting objects before the blowpipe.
It alloys readily when heated with iron, lead, and several of
the metals, and is also attacked by caustic potash and phos-
phoric acid, in contact with carbon ; and consequently there
should be caution when heating it not to expose it to these
agents.
It is employed for coating copper and brass ; also for
painting porcelain and giving it a steel lustre, formerly
highly prized. It admits of being drawn into wire of ex-
treme tenuity.
Platinum was formally coined in Russia. The coins had
the value of 11 and 22 rubles each.
This metal fuses readily before the "compound blow-
pipe ; " and Dr. Hare succeeded in 1837 in melting twenty-
eight ounces into one mass. The metal was almost as malle-
able and as good for working as that obtained by the other
process; it had a specific gravity of 19-8. He afterwards
succeeded in obtaining from the ore masses which were 90
PALLADIUM. 127
per cent, platinum, and as malleable as the metal in ordi-
nary use, though somewhat more liable to tarnish, owing to
some of its impurities. Deville and Debray have perfected
this process, and have melted over 25 pounds of platinum
in less than three-quarters of an hour. In the process the
osmium present is oxidized and thus removed.
Platin-iridium. Grains of iridium have been obtained at Nischne
Tagilsk, consisting of 76 '8 iridium, and 19 '64 platinum, with some
palladium and copper. A similar platin-iridium has been obtained at
Ava, in the East Indies. Another, from Brazil, contained 27 '8 iridium,
55 '5 platinum, and 6 '9 of rhodium.
Iridosmine. A compound of iridium and osmium from the platinum
mines of Eussia, South America, the East Indies, and California. The
crystals are pale steel-gray hexagonal prisms ; usually in flat grains.
H. = 6 -7. G. = 19 -5-21 1. Malleable with difficulty.
The composition varies. One variety, called Newjanskite, contains
iridium 40 '8, osmium 493, rhodium 32, iron 0'7. Another, Sisser-
skite, iridium 25*1, osmium 74*9, and iridium 20, osmium 80. But
analysis affords also from 0'5 to 12 3 of rhodium, and 02 to 6 '4
of the rarer metal ruthenium, with traces usually of platinum, cop-
per and iron. The grains are distinguished by their superior hardness
from those of platinum, and also by the peculiar odor of osmium when
heated with nitre. Iridosmine is common with the gold of Northern
California, and injures its quality for jewelry. Occurs sparingly in
the gold washings on the rivers Du Loup and Des Plantes, Canada.
The metal iridium is extremely hard, and is used, as well as rho-
dium, for points to the nibs of gold pens. Its specific gravity is 21 '8.
Laurite. In minute octahedrons. A ruthenium sulphide, with 3
per cent, of osmium. From platinum sands of Borneo and Oregon.
Palladium.
Isometric. In minute octahedrons. Occurs mostly in
grains, sometimes composed of divergent fibres. Color
steel-gray, inclining to silver- white. Ductile and malleable.
H. 4-5-5. G. =11 -3-12 -2.
Consists of palladium, with some platinum and iridium.
Fuses with sulphur, but not alone.
Obs. Occurs in Brazil with gold, and is distinguished
from platinum, with which it is associated, by the divergent
structure of its grains. It was discovered by Wollaston, in
1803. Selenpalladite, or Allopalladium, is native palladium
in hexagonal tables from Tilkerode in the Hartz. It is re-
ported also from St. Domingo and the Urals. Porpezile
is palladium gold, or gold containing about 10 per cent, of
palladium ; three samples assayed at the Eio de Janeiro
mint yielding 11-1, 9 -75, and 7 '7 per cent, of palladium.
128 DESCRIPTIONS OF MINERALS.
This metal is malleable, and when polished has a whitish
steel-like lustre which does not tarnish. A cup weighing
3J pounds was made by M. Breant in^the mint at Paris, and
is now in the garde-meuble of the French crown. In hard-
ness it is equal to fine steel. 1 part fused with 6 of gold
forms a white alloy ; and this compound was employed, at
the suggestion of Dr. W^llaston, for the graduated part of
the mural circle constructed by Trough ton for the Eoyal
Observatory at Greenwich. Palladium has been employed
also for certain surgical instruments.
MERCURY.
Mercury occurs native ; alloyed with silver forming na-
tive amalgam ; and in combination with sulphur, selenium,
chlorine, or iodine, and with sulphur and antimony in some
tetrahedrite. Its ores are completely volatile, excepting
when silver or copper is present.
Native Mercury.
Isometric. Occurs in fluid globules scattered through the
gangue. Color tin-white. G. — 13-56. Becomes solid and
crystallizes at a temperature of —39° F.
Mercury, or quicksilver, as it is often called (a translation
of the old name "argentum vivum)," is entirely volatile
before the blowpipe, and dissolves readily in nitric acid.
Obs. Native mercury is a rare mineral, yet is met with
at^the different mines of this metal, at Almaden in Spain,
Idria in Carniola (Austria), in Hungary, Peru, and in Cali-
fornia. It is usually in disseminated globules, but is some-
times accumulated in cavities so as to be dipped up in
pails.
Mercury is used for the extraction of gold and silver ores.
It is also employed for silvering mirrors, for thermometers
and barometers, and for various purposes connected with
medicine and the arts.
Native Amalgam. See page 117.
Cinnabar. — Mercury Sulphide.
Rhombohedral. R^R=12° 3G'. Cleavage lateral, high-
ly perfect. Crystals often tabular, or six-sided prisms. Also
massive ; sometimes in earthy coatings.
SILVER. 129
Lustre unmetallic, of crystals adamantine ; often dull.
Color bright red to brownish red, and brownish black.
Streak scarlet-red. Sub transparent to nearly opaque. H. =
2-2-5. G.= 8-5-9. Sectile.
Composition. Hg S2 = Sulphur 13-8, mercury 86-2. It
often contains impurities. The liver ore, or hepatic cinna-
bar, contains some carbon and clay, and has a brownish
streak and color. The pure variety volatilizes entirely be-
fore the blowpipe.
Diff. Distinguished from red oxide of iron and chromate
of lead by vaporizing before the blowpipe ; from realgar by
giving off on charcoal no alliaceous fumes.
Obs. Cinnabar is the ore from which the principal part
of the mercury of commerce is obtained. It is when pure
identical with the pigment vermilion. It occurs mostly in
connection with siliceous, talcose and argillaceous slates, or
other stratified deposits, both the most ancient and those of
more recent date. The mineral is too volatile to be expected
in any abundance in proper igneous or crystalline rocks, yet
has been found sparingly in granite.
The localities are mentioned beyond.
Metacinnabarite is the same compound with cinnabar, but differs in
crystallization ; it is from Redington Mine, Lake County, California.
Guadalcazarite, of Mexico, is Hg S in which a little of the sulphur
is replaced by selenium.
Calomel or Horn Quicksilver. A tough, sectile mercury chloride, of
a light yellowish or grayish color, and adamantine lustre, translucent
or subtranslucent, crystallizing in secondaries to a square prism.
H.=l-2. G.=6'48. It contains 151 per cent, of chlorine, and 84 '9
of mercury.
lodic Mercury. . A reddish-brown ore, from Mexico.
Tiemannite. A dark steel-gray mercury selenide, from the Hartz,
and the vicinity of Clear Lake, California.
Coloradoite. A grayish black mercury telluride, with G.=8'627,
from the Keystone and Mountain Lion Mines, Colorado. (Genth.)
Magnolite. A mercurous tellurate, Hg 0« Te, from Magnolia dis*
trict, Colorado.
General Remarks.— Tlie following are the regions of the principal
mines of mercury. At Idria, in Austria (discovered in 1407), where
the ore is a dark bituminous cinnabar distributed through a blackish
shale or slate, containing some native mercury ; at Almaden, in Spain,
near the frontier of Estremadura, in the province of La Mancha, in
argillaceous beds and grit rock, which are intersected by dikes of
" black porphyry " and granite — mines mentioned by Pliny as afford-
ing vermilion to the Greeks, 700 years before the Christian era ; in
the Palatinate on the Rhine ; in Hungary; Sweden ; several points in
France ; Ripa, in Tuscany ; in Shensi, in China ; at Arqueros, %
130
DESCRIPTIONS OF MINERALS.
Chili •, at Huanca Yelica and some other points in Peru ; at St. Onofre
and other places in Mexico ; in California and Idaho.
The most noted of the California mines, New Almaden, is situated
in Mine Hill, Santa Clara County, south of San Francisco. The rocks
are altered Cretaceous slates, talcose in part, with beds of serpentine
either side, and associated also with beds of jasper or siliceous slate.
The New Idria mine is in Fresno County, in the Mt. Diablo Range, and
was discovered in 1855. The rocks are more or less altered silico-
argillaceous and siliceous slates and sandstones, and the cinnabar is
distributed irregularly through them ; between this and the Aurora
Mine on San Carlos (the highest peak of the Diablo Range, 4,977 feet),
there is much serpentine (in which is chromic iron) and siliceous rock
or slate. In Napa Valley, Napa County, north of San Francisco, there
are other valuable mines situated in rocks closely similar, as Whitney
states, to those affording quicksilver at New Almaden. They are in
a serpentine belt, the cinnabar being in some places in the serpentine,
but mostly in the peculiar siliceous rock associated with it. Native
mercury occurs with the cinnabar.
The product of the California mines of mercury in 1874, is given as
follows by Raymond, in his " Mineral Resources for 1875" :
New Almaden Santa Clara County 9, 084 flasks.
New Idria Fresno
Cerro Bonito "
California Napa
Manhattan. .
Phoenix
Washington.
Redington Lake
California Borax.
Great Western . .
Buckeye Colusa
Missouri Sonoma
Oakland ' '
Saint John. . ..Solano
.7,000
900
,3,000
, 620
, 685
. 200
.7,200
, 570
1,900
, 700
, 200
307
1,900
Which, with the additions from a few other less productive open-
ings, make a total of 34,254 flasks, or over 2,400,000 Ibs. The yield
in 1867 was 44,386 flasks, or about 3,400,000 Ibs. The total yield of
the world in 1872, is stated by Phillips at 6,670,000 Ibs. avoirdupois.
COPPER.
Copper occurs native in considerable quantities ; and also
combined with oxygen, sulphur, selenium, arsenic, anti-
mony, chlorine, and as carbonate, phosphate, arsenate, sul-
phate, and vanadate. The ores of copper vary in specific
gravity from 3-5 to 8-5, and seldom exceed 4 in hardness.
ORES OF COPPER. 13^
Native Copper.
Isometric. In octahedrons ; no cleavage apparent. Often
in plates or masses, or arborescent and filiform shapes.
Color copper-red. Ductile and malleable. H. =2*5-3.
G.=8-84.
Native copper often contains a little silver disseminated
throughout it. Before the blowpipe it fuses readily, and on
cooling it is covered with a black oxyd. Dissolves "in nitric
acid, and produces a deep azure-blue solution on the addition
of ammonia.
Obs. Native copper accompanies the ores of copper, and
usually occurs in the vicinity of dikes of igneous rocks.
Siberia, Cornwall, and Brazil are noted for the native cop-
per they have produced. A mass, supposed to be from Bahia,
now at Lisbon, weighs 2,616 pounds. South of Lake Supe-
rior about Portage Lake on Keweenaw Point, and also, less
abundantly, on the Ontanagon Eiver, and at some other
points in that region, native copper occurs mostly in veins
in trap, and also in the enclosing sandstone. A mass
weighing 3,704 Ibs. has been taken from thence to Wash-
ington City ; it is the same that was figured hy School-
craft, in the American Journal of Science, volume iii., p.
201. One large mass was quarried out in the '' Cliff Mine,"
whose weight has been estimated at 200 tons. It was 40
feet long, 6 feet deep, and averaged 6 inches in thickness.
This copper contains, intimately mixed with it, about y\ per
cent, of silver. Besides this, perfectly pure silver, in strings,
masses, and grains, is often disseminated through the cop-
per, and some masses, when polished, appear sprinkled with
large white spots of silver, resembling, as Dr. Jackson ob-
serves, a porphyry with its feldspar crystals. Crystals of
native copper are also found penetrating masses of prehnite
and analcite in the trap rock. This mixture of copper and
silver cannot be imitated by art, as the two metals form an
alloy when melted together. It is probable that the separa-
tion in the rocks is due to the cooling from fusion being
so extremely gradual as to allow the two metals to solidify
separately, at their respective temperatures of solidification —
the trap being an igneous rock, and ages often elapsing, as
is well known, during the cooling of a bed of lava, covered
from the air. Native copper occurs sparingly in St. Ignace
and Michipicoton Islands, Lake Superior.
132 DESCRIPTIONS OF MINERALS.
Small specimens of native copper hare been found in the
States of New Jersey, Connecticut, and Massachusetts, where
the Triassic formation occurs. One mass from near Somer-
yille, N. J., weighs 78 pounds, and is said originally to have
weighed 128 pounds. Within a few miles to the north of
New Haven, Conn., one mass of 90 pounds, and another of
200, besides other smaller, have been found in the drift, all
of which came from veins in the trap or associated Triassic
sandstone. Near New Brunswick, N. J., a vein or sheet of
copper, from a sixteenth to an eighth of an inch thick, has
been observed and traced along for several rods.
Native copper occurs also in South Australia ; it is stated
that a single train from the Moonta Mine carried away at
one time forty tons of native copper.
Chalcocite. — Copper Glance. Vitreous Copper Ore. Redrutliite.
Trimetric. /: 7=119° 35', Cleavage
parallel to /, but indistinct. Also in com-
pound crystals like aragonite. Often mas-
sive.
Color and streak blackish lead-gray ; often
tarnished blue or green. Streak sometimes
shining. H.=2'5-3. G. =5-5-5 -8.
Composition. Cu2 S— Sulphur 20-2, cop-
per 79-8=100. B.B. on charcoal gives off
fumes of sulphur, fuses easily in the exte-
rior flame ; and after the sulphur is driven
off, a globule of copper remains. Dissolves
in heated nitric acid, with a precipitation of the sulphur.
Diff. Resembles argentite, but it is not sectile, like that
ore, and they afford different results before the blowpipe.
The solution of the ore in nitric acid covers an iron plate
(or knife blade) with copper, while a similar solution of the
silver ore covers a copper plate with silver.
Obs. Occurs with other copper ores in beds and veins.
At Cornwall, splendid crystallizations occur. Siberia, Hesse,
Saxony, the Banat, Chili, etc., afford this ore.
In the United States, a vein affording fine crystallizations
occurs at Bristol, Conn. Other localities are at Wolcott-
ville, Simsbury, and Cheshire, Conn. ; at Schuyler's Mines,
and elsewhere, N. J. ; in the U. S. copper-mine district,
Blue Eidge, Orange County, Virginia; between New Market
and Taneytown, Maryland ; and sparingly at the copper
ORES OF COPPER. 133
mines of Michigan and the Western States; also at some
mines north of Lake Huron ; in the San Juan mining region,
Colorado ; north of Gila Riva, near the borders of New
Mexico and Arizona ; at the Bruce Mines, Lake Huron,
and at Prince's Mine, Spar Island, and on Michipicoton
Islands, Lake Superior.
Covellite, or Blue Copper. A dull blue-black massive mineral, with
the composition CuS. G=3'8. It contains 66*5 per cent, of copper.
Harrisite. A copper glance with cubic cleavage, from Canton Mine,
Ga. ; probably a pseudomorph after galenite.
Chalcopyrite.— Copper Pyrites. Copper-and-Iron Sulphide.
Dimetric. Crystals tetrahedral or
octahedral ; sometimes compound.
/ A 7=109° 53', and 108° 40'. Cleav-
age indistinct. Also massive, and of
various imitative shapes.
Color brass-yellow, often tarnished
deep yellow, and also iridescent.
Streak unmetallic, greenish black, and
but little shining. H.=3'5-4. G.
=4-15-4-3.
Composition. CuFe S2 = Sulphur
34-9, copper 34-6, iron 30-5 = 100. Fuses B.B. to a globule
which is magnetic, owing to the iron present. Gives sulphur
fumes on charcoal. With soda on charcoal affords a glo-
bule of metallic iron with copper. The usual effect with
nitric acid.
Diff. This ore resembles native gold, and also pyrite. It
is distinguished from gold by crumbling when it is attempted
to cut it, kistead of separating in slices ; and from pyrite in
its deeper yellow color, and in yielding easily to the point of
a knife, instead of striking fire with a steel.
Obs. Copper pyrites occurs in veins intersecting gneiss
and other rnetamorphic rocks ; also in those connected with
eruptive rocks ; and sometimes in cavities or veins in ordi-
nary stratified rocks. It is usually associated with pyrite,
and often with galenite, blende, and copper carbonates. The
copper of Fahlun, Sweden, is obtained mostly from this ore,
where it occurs with serpentine in gneiss. Other mines of
this ore are in the Hartz, near Goslar ; in the Banat, Hun-
gary, Thuringia, etc. The Cornwall ore is mostly of this
kind. As prepared for sale at Kedruth it rarely yields 12
134 DESCRIPTIONS OP MINERALS.
per cent., and generally only 7 or 8, and occasionally as little
as 3 to 4 per cent, of metal ; "6J per cent, of metal may be
considered an average of the produce of the total quantity of
ore sold." (Phillips, 1874.) Such poverty of ore is only made
up by its facility of transport, the moderate expense of fuel,
or the convenience of smelting. Its richness may generally
be judged of from the color: if of a fine yellow hue, and
yielding readily to the hammer, it is a good ore ; but if hard
and pale yellow it contains much pyrite, and is of poor
quality.
In the United States there are many localities of this ore.
It occurs in mines in Vermont, at Strafford ; and at Shrews-
bury, Corinth, Waterbury ; also in New Hampshire, Maine,
Massachusetts, and Connecticut; in New York, at the Ancram
lead mine ; also near Eossie, and at Wurtzboro' ; in Penn-
sylvania, at Morgantown ; in Virginia, at the Phenix copper
mines, Fauquier County, and at the Walton gold mine,
Luzerne County; in Maryland, in the vicinity of Liberty and
New London in Frederick County; and at the Patapsco
mines near Sykesville ; in North Carolina, in Davidson and
Guilford counties. In Michigan, where native copper is so
abundant, this is a rare ore ; but it occurs at Presqu'isle, at
Mineral Point, and in Wisconsin, where it is the predomi-
nating ore ; in Tennessee, in Polk County, at the Iliwassee
mines ; in the San Juan mining region, Colorado ; in Lan-
der Co., and elsewhere, Nevada ; at Copperopolis, Calaveras
Co., California ; also at the Bruce and other mines on Lake
Huron ; and Michipicoton Islands, in Lake Superior.
Cubanite is a copper-and-iron sulphide, containing Sulphur 39 '0,
iron 38'0, copper 19 '8, silica 2'3=99'12.
Bornite. — Erubescite. Variegated Copper Pyrites.
Isometric. Cleavage octahedral in traces. Occurs in oc-
tahedrons and dodecahedrons. Also massive.
Color between copper-red and pinchbeck-brown. Tar-
nishes rapidly on exposure. Streak pale grayish-black and
but slightly shining. Brittle. H. = 3. G. = 5.
Composition. Cu3Fe S3= Sulphur 28-6, copper 55 -58, iron
16-36 ; but varies much.
The ore of Bristol, Conn., afforded Sulphur '25 '83, copper
61-79, iron 11-77=99-39.
B.B. on charcoal fuses to a brittle globule attractable by
ORES OF COPPER. 135
»
the magnet ; dissolves in nitric acid, with separation of
sulphur.
I) iff. This ore is distinguished from the preceding by its
pale reddish-yellow color, and its rapidly tarnishing and
becoming of bluish and reddish shades of color, the quality
to which the name erubescite, from the Latin word for to
blush, alludes.
Obs. Occurs, with other copper ores, in granitic and al-
lied rocks, and also in stratified formations. The mines of
Cornwall have afforded crystallized specimens, and it is there
called, from its color, " horse-flesh ore." Other foreign
localities of massive varieties are Ross Island, Killarney, Ire-
laud ; Norway, Hessia, Silesia, Siberia, and the Banat.
Fine crystallizations were formerly obtained at the Bristol
copper mine, Conn., in granite; and also in red sandstone,
at Cheshire, in the same State, with malachite and barite.
Massive varieties occur at the New Jersey mines, and in
Pennsylvania.
Orookesite. A copper selenide, containing 17 '25 per cent, of thallium,
and a little silver.
Domeykite, Alyodonite and Whitneyite are copper arsenides ; Ber-
zelianite, a copper selenide ; Eucairite, a copper-and-silver selenide.
Tennantite. A compound of copper, iron, sulphur, and arsenic. It
occurs in dodecahedral crystals, brilliant, with, a dark lead-gray color,
and reddish-gray streak. From the Cornish mines near Redruth and
St. Day in Cornwall.
Tetrahedrite. — Gray Copper. Fahlerz.
Isometric and tetrahedral. Occurs in tetrahedral forms.
Cleavage octahedral in traces.
Color between steel-gray and iron-
black. Streak nearly like the color,
sometimes inclined to b"own and
cherry-red. Rather brittle. H.=3-
4-5. G. =4-5- 5-12.
Composition. Cus S7 Sb2 ( = 4 Cu2
S + Sb8 S3), but with part of the cop-
per replaced usually by iron and
zinc, and sometimes silver or quick-
silver, and part of the antimony by
arsenic, and rarely bismuth. It 'sometimes contains 30 per
cent, of silver in place of part of the copper, and is then
called argentiferous tetrahedrite. The amount of arsenic
varies from 0 to 10 per cent. One variety from Spain in-
cluded 10 per cent, of platinum, and another from Hohen'
136 DESCRIPTIONS OF MINERALS.
•
stein some gold. Specimens from Schwatz, and some oilier
localities, contain 15 to 18 per cent, of mercury, and are
called ^/Huiio/i/c. A kind containing !) (<> i:> percent, of
lead and 10 to 13 of silver, has been called MalinotrHkilc.
Obs. The Cornish mines, Andnwibefg in the llariz,
Krcinnit?: in Hungary, Freiberg in Saxony, KapniU in Tran-
sylvania, and Dillenberg in Nassau, alTord line crysialliza-
tions of this ore. It is a common ore in the Chilian mines,
and it is worked there and elsewhere for copper and often
also for silver. Occurs also in Mexico ; in Mariposa, and
Shasta counties, Cal. ; abundantly at the Sheba and De Soto
mines, Ilumboldt Co.; Nevada, near Austin in Lander Co. ;
in the San Juan region, Colorado; at the lleint/elman
Mine, and the Santa Rita Mine, in Ari/ona ; also in line
crystallizations in the caves of Huallanea, on the Peruvian
Andes, at a height of about 14,700 feet, an ore yielding
much silver.
Bournonite, Contains Sulphur 29'f>, antimony 05-0, load 42*24, cop-
per 18*0 — 100. Its crystals arc modified rectangular prisms, of a steel-
gray color and streak, and arc often compounded into shapes like a
cog- wheel, \\hence it is called trlu'.l-orc. 11. =2 '5-3. G. — 5-700.
Prom the Tyrol, Hart/, Transylvania, Saxony, Cornwall, and Siberia.
Other sulphautiiuonites or sulpharsenites of copper are (•/m/cdftihitc,
Empl(t'tit<\ Itinnitc, Stylotypite, AiktHid', timiryit^, Polybasitc. 1'oly-
basitc contains also silver.
Atacamite. — Copper Oxichloride.
Trimetrio ; in rhombic prisms and other forms ; also
granular massive. Color green to blackish green. Lustre
adamantine to vitreous. Streak apple-irreen. Translucent
to subtranslucent. II. = 3-3-5. G. = 3-75-3-9. Com-
position, Cu Clj + 3 Cu Oa H8= Chlorine 1(1 •(»•!, oxygen 11 '25,
copper 11*25, water 12-G6 = iOO. From the Atacama ilesert,
hdween Chili and IVru. and clewhcre in Chili; also from
Bolivia, Vesuvius, Saxony, Spain, Cornwall.
'
Cuprite. — Red Copper Ore.
Isometric. In regular octahedrons, and modified forms of
the same. Cleavage octahedral. Also massive, and some-
times earthy.
Color dcevp red, of various shades. Streak brownish red.
Lustre adamantine or submetallic ; also earthy. Subtrans-
parent to nearly opaque. Brittle. H. = 3'5-4. G. =5*85-
C-15.
ORES OF COPPER.
137
Civ, 0 = Oxygen 11*2, copper 88'8. B.B.
on charcoal, yields a globule of copper. Dissolves in nitric
acid. The earthy varieties have been called tile ore, from
the color.
8.
Diff. From cinnabar it differs in not being volatile before
the blowpipe ; and from red iron ore in yielding a bead of
copper on charcoal, and copper reactions.
Obs. Occurs with other copper ores in the Banat, Thu-
ringia, Cornwall, at Chessy near Lyons, in Siberia, and Bra-
zil. The octahedrons are often green, from a coating of
malachite.
In the United States, it has been observed crystallized and
massive at Schuyler's, Somerville, and the Flemington cop-
per mines, N. J. ; also near New Brunswick, N. J. ; at
Bristol, Conn.; near Ladenton, Rockland County, N. Y.; in
the Lake Superior region.
Tenorite, Melaconite, or Black Copper. An oxide of cop-
per, CuO, occurring as a black powder, and in dull black
masses and botryoidal concretions, in veins or along with
other copper ores ; also in iron-gray flexible scales, in the
Vesuvian lavas. It is an abundant ore in some of the cop-
per mines of the Mississippi Valley, and yields GO to 70 per
cent, of copper. It results from the decomposition of the
sulphides and other ores. At the Hiwassee Mine, Polk Co.,
Tennessee, it has been abundant. It was formerly found of
excellent quality in the Lake Superior copper region.
Chalcanthite.— Blue Vitriol. Sulphate of Copper.
Triclinic. In oblique rhomboidal prisms. Also as an
efllorescence or incrustation, and stalactitic.
Color deep sky-blue. Streak uncolored. Subtransparcnt
to translucent. Lustre vitreous. Soluble, taste nauseous
and metallic. H.=2-2'5. G.=2-21.
138 DESCRIPTIONS OF MINERALS.
Composition. Cu Ot S + 5 aq= Sulphuric acid (or sulphur
trioxide) 32'1, copper oxide 31*8, water 36*1. A polished
plate of iron in solutions becomes covered with copper.
Obs. Occurs with the sulphides of copper as a result of
their decomposition, and is often in solution in the waters
flowing from copper mines. Occurs in the Hartz, at Fahlui\
in Sweden, and in many other foreign copper regions ; in,(
the Hiwassee copper mine, Tennessee ; the Canton mine,
Georgia ; at Copiapo, Chili.
Blue vitriol is much used in dyeing operations and in the
printing of cotton and linen ; also for various other pur-
poses in the arts. It has been employed to prevent dry rot,
by steeping wood in its solution : and it is a powerful pre-
servative of animal substances ; when imbued with it and
dried, they remain unaltered. It is afforded by the decom-
position of copper pyrites, in the same manner as green vit-
riol from iron pyrites ; but it is manufactured for the arts,
chiefly from old sheathing-copper, copper turnings, and cop-
per refinery scales.
In Frederick County, Maryland, blue vitriol is made from
a black earth which is an impure oxide of copper with cop-
per pyrites.
In some mines, the solution of sulphate of copper is so
abundant as to afford considerable copper, which is obtained
by immersing clean iron in it, and is called copper of cemen-
tation. At the copper springs of Wicklow, Ireland, about
500 tons of iron were laid at one time in the pits ; in about
12 months the bars were dissolved, and every ton of iron
yielded a ton and a half, and sometimes nearly two tons, of
a precipitated reddish mud, each ton of which produced 16
cwt. of pure copper. The Eio Tinto Mine in Spain is an-
other instance of working the sulphate in solution. These
waters yield annually 1,800 cwt. of copper, and consume
2,400 cwt. of iron.
Brochantite. An insoluble copper sulphate, containing 17 '7 per
cent, of sulphur trioxide. Color emerald-green. In tabular rhombic
crystals, from the Urals, Retzbanya, Cornwall, Mexico, Chili, Aus-
tralia. Krisumgtie and Konigite are the same species.
Langite, CyanotricMte (Velvet copper ore), Kronkite, Philippite,
Enysite, Linarite, Dolerophanite, Hydrocyanitc, are other sulphates
containing copper, the last two anhydrous ; and Gonnellite is another
containing chlorine, from Cornwall.
The Copper tungstate, Cuprotungstite, occurs of a yellowish-green
color in Chili.
g
b
ORES OF COPPER. 139
Olivenite. — Hydrous Copper Arsenate.
Trimetric. /A/— 92° 30'. In prismatic crystals, and
also fibrous and granular massive . Olive-green, and of
other greenish shades, to liver and wood-brown. Streak
olive-green to brown. Substransparent to opaque. Brittle.
H. = 3. G.=4-l-4-4.
Composition. Cu4 09 As2= Arsenic pentoxide 40-66, copper
oxide 56-15, water 3;19 = 100. Fuses very easily, coloring
the flame bluish green. B.B. fuses with deflagration, giv-
ing off arsenical fumes, and affords a brittle globule, which
with soda yields metallic copper.
Obs. From Cornwall, the Tyrol, Siberia, Chili, and other
places.
Besides the above, there are the following salts of copper :
Copper Arsenate*. — Euchroite has a bright emerald -green color, and
contains 33 per cent, of arsenic acid, and 48 of oxide of copper ; occurs in
modified rhombic prisms ; H.=8*75 ; G=8*4 ; from Libethen, in Hun-
ary. Clinoclasite (Aphancsite] is of a dark verdigris-green inclining to
lue, and also dark blue; H. =25-3; G. =4 19-4 '3(3. It contains 62'7 per
cent, of copper oxide ; from Cornwall. Erinite has an emerald-green
color, and occurs in mammillated coatings ; H.=4'5-5 ; G.=4'04; con-
tains 59 '4 per cent, of copper oxide ; from Limerick, Ireland. Liroco-
nite varies from sky-blue to verdigris-green ; occurs in rhombic prisms,
sometimes an inch broad ; H.=2-2'5; G.=2-8-2'98. Chalcophylliti
(copper mica} is remarkable for its thin foliated or mica-like structure •
color emerald or grass-green ; H. =2 ; G. =2 '55. Contains 58 per cent.
of copper oxide ; from Cornwall and Hungary. Tyrolite (Copper
froth) is another arsenate of a pale apple-green and verdigris-green
color ; it has a perfect cleavage ; it contains 43 9 per cent, of copper
oxide ; from Hungary, Siberia, the Tyrol, and Derbyshire. Cormcatt-
iU and Cldorotile, are names of other copper arsenates. These dif-
ferent arsenates of copper give an alliaceous odor when heated on
charcoal before the blowpipe.
Copper Phosphates. — Pseudomalachite (Phospliochalcite, Ehlite, Dt
Ttydrite) occurs in very oblique crystals, or massive and incrusting, and
has an emerald or blackish-green color; H. =45-5 ; G. =4'34 ; contains
64 to 70 per cent, of copper oxide ; from near Bonn, on the Rhine, and
also from Hungary. Libethenite has a dark or olive-green color, and
occurs in crystals, usually octahedral in aspect, and massive ; H. =
4; G.=3'6-8-8; contains 66 '5 per cent, of oxide of copper; from
Hungary and Cornwall. Other copper phosphates are Veszelyite,
Tagilite, Isoclasite. Torbernite is a copper-and-uranium phosphate.
These phosphates give no fumes before the blowpipe, and have the
reaction of phosphoric acid.
Copper Vanadates. — Volborthite is a copper-and- calcium vanadate
from the Urals ; and Mottrammite and Psittacinite, copper-and-lead
vanadates, the former from England, and the latter from gold mines
in Silver Star district, Montana.
Riwtite. Yellowish-green copper antimonate and carbonate.
140 DESCKIPTIONS OP MINERALS.
Malachite. — Green Copper Carbonate.
Monoclinic. Usual in incrustations, with a smooth tube-
rose, botryoidal, or stalactitic surface ; structure finely and
firmly fibrous. Also earthy.
Color light green, streak paler. Usually nearly opaque ;
crystals translucent. Lustre of crystals adamantine inclin-
ing to vitreous ; but fibrous incrustations silky on a cross
fracture. Earthy varieties dull. H.=3'5-4. G.=3'7-4.
Composition. Cu2 04 C + H2 0 = Carbon dioxide (or car-
bonic acid) 19-9, copper oxide 71*9, water 8*2=100. Dis-
solves with effervescence in nitric acid.
B.B. decrepitates and blackens, colors the flame green,
and becomes partly a black scoria. AVith borax it fuses to a
deep-green globule, and ultimately affords a bead of copper.
Diff. Eeadily distinguished by its copper-green color and
its associations with copper ores. It resembles a siliceous
ore of copper, chrysocolla, a common ore in the mines of the
Mississippi Valley; hut it is distinguished by its complete so-
lution and effervescence in nitric acid. The color also is not
the bluish green of chrysocolla.
Obs. Green malachite usually accompanies other ores of
copper, and forms incrustations, which, when thick, have
the colors banded and delicate in their shades and blending.
Perfect crystals are quite rare. The mines of Siberia, at
Nischne Tagilsk, have afforded great quantities of this ore.
A mass, partly disclosed, measured at top 9 feet by 18 ; and
the portion uncovered contained at least half a million
pounds of pure malachite. Other noted foreign localities
are Chessy, in France; Sandlodge, in Shetland; Schwatz
in the Tyrol ; Cornwall ; the Island of Cuba ; Serro do
Bembe, west coast of Africa ; copper mines of Australia ;
Chili.
The copper mine of Cheshire, Conn., has afforded hand-
some specimens ; also Morgantown, Perkiomen, and Phoenix-
ville, Penn. ; Schuyler's Mine, and the New Brunswick
copper mine, N. J. ; it occurs also in Maryland, between
Newmarket and Taneytown ; and in the Catoctin Mountains ;
in the Blue Kidge, Penn., near Nicholson's Gap ; also in
ntic district, Utah.
TiAt Mineral Point, Wisconsin, a bluish silico-carbonate of
ocpper occurs, which is for the most part chrysocolla, or a
mixture of this mineral with the carbonate.
ORES OF COPPER. 141
This mineral receives a high polish and is used for tables,
mantelpieces, vases ; and also ear-rings, snuff-boxes, and va-
rious ornamental articles. It is not much prized in jewelry.
At Versailles there is a room furnished with tables, vases,
and other articles of this kind ; and similar rooms are to be
found in many European palaces.
Malachite is sometimes passed off in jewelry as turquois,
though easily distinguished by its shade of color and much
inferior hardness. It is a valuable ore when abundant ; but
it is seldom smelted alone, because the metal is liable to es-
cape with the liberated volatile ingredient.
Azurite.— Blue Copper Carbonate. Blue Malachite.
Monoclinic. In modified oblique rhombic prisms, the
crystals rather short and stout ;
lateral cleavage perfect. Also mas-
sive. Often earthy.
Color deep blue, azure blue, Ber-
lin blue. Transparent to nearly
opaque. Streak bluish. Lustre
vitreous, almost adamantine. Brit-
tle. H.=3-5-4-5. G. = 3'5-3'85.
Composition. Cu3 07 C2 + H2 0 =
Carbon dioxide 25 '6, copper oxide
69*2, water 5-2. B.B. and in acids like the preceding.
Obs. Azurite accompanies other ores of copper. Chessy,
France, has afforded fine crystals ; found also in Siberia ; in
the Banat ; near Redruth in Cornwall ; at Phcenixville, Pa.,
in crystals ; in Wisconsin near Mineral Point ; as incrusta-
tions, and rarely as crystals, near Sing Sing, N. Y. ; near
New Brunswick, N. J. ; near Nicholson's Gap, in the Blue
Ridge, Pa.
When abundant it is a valuable ore of copper. It makes
a poor pigment as it is liable to turn green.
Aurichalcite (Buratite) is a hydrous copper-and-zinc carbonate, or a
cuprous hydrozincite, pale green to sky-blue in color ; from the Altai,
Retzbanya, Chessy in France, Tyrol, Spain, Leadhills in Scotland, and
Lancaster, Pa.
Dioptase. — Copper Silicate.
Rhombohedral. 72 A # = 126° 24'. Occurs in six-sided
prisms with rhombohedral terminations. Color emerald-
green. Lustre vitreous. Transparent to nearly opaque.
H.=5. G. =3-28-3 -35.
142
DESCRIPTIONS OF MINERALS.
Composition. CuII2 04 Si = Silica 38-1, copper oxide 50-4,
water 11*5 = 100. B. B. with soda on charcoal yields copper,
and this, with its hardness, distinguishes it from the spe-
cies it resembles.
Obs. From the Khirgeez Steppes of Siberia.
Chrysocolla. — Hydrous Copper Silicate.
Usually as incrustations ; botryoidal and massive. Also
in thin seams and stains ; no fibrous or granular structure
apparent, nor any appearance of crystallization.
Color bright green, bluish green. Lustre of surface of
incrustations smoothly shining ; also earthy. Translucent
to opaque. H. = 2-4. G. = 2-2 -4.
Composition. Cu03Si + 2 aq= Silica 34*2, copper oxide
45-3, water 20-5=100'.
NEW JERSEY.
Bowen.
Beck.
. 45.2
42-6
. 37-3
40-0
. 17-0
16-0
_
1-4
SIBERIAN.
Von Kobell. Berthier
Oxide of copper. . . 40'0 55*1
Silica 36-5 35 "4
Water 20'2 28'5
Carbonic acid 2'1
Oxide of iron 1-0
The mineral varies much in the proportion of its consti-
tuents, as it is not crystallized.
B.B. it blackens in the inner flame, and yields water
without melting. With soda on charcoal yields a globule
of copper.
Diff. Distinguished from green malachite as stated under
that species.
Obs. Accompanies other copper ores in Cornwall, Hun-
gary, the Tyrol, Siberia, Thuringia, etc. In Chili it is
abundant at the various mines. In Wisconsin and Missouri
it is so abundant as to be worked for copper. It was for-
merly taken for green malachite. It also occurs at the Som-
erville and Schuyler's mines, N. J., at Morgantown, Penn.,
and Wolcottville, Conn.
This ore in the pure state affords 30 per cent, of copper ;
but as it occurs in the rock will hardly yield one-third thia
amount. Still, when abundant, as it appears to be in the
Mississippi Valley, it is a valuable ore.
General EemarTcs. — The most valuable sources of copper for the
arts are native copper, chalcopyrite or "yellow copper ore," chalcocite
or "copper glance," bornite or "variegated copper ore," malachite
ORES OF COPPER. 143
or " green carbonate of copper," chrysocolla or' silicate," cuprite or
"red oxide of copper ; " and occasionally tenorite or " black copper."
The principal copper regions, exclusive of the American, are as
follows. The Cornwall and Devon, England, where the ere is mostly
chalcopyrite ; about Mansfeld, in Prussia, having the ore distributed
through a bed of red shale in the Permian (Kupferschiefer), about
eighteen inches thick, making about 2^ per cent, of the bed ; the
Urals on their western slope, in the Permian, as in Mansfeld ; also
more productively on the eastern side of the Urals, at the Nischne
Tagilsk and Bogoslowskoi mines, in Silurian limestone where tra-
versed by eruptive rocks, and at the Gumeschewskoi mine, in argil-
laceous shale, the ore chiefly malachite and cuprite ; in France, at
Chessy, near Lyons, of malachite and azurite, now of little value ; in
Norway, at Alten, and in Sweden, at Fahlun ; in Hungary, at Scheni-
nitz, Kremnitz, Kapnik, and the Banat ; in Italy, at Monte Catini ; in
Spain, in the province of Huelva, where is the Rio Tinto mine, which
affords chalcopyrite, and also the sulphate (p. 138) ; in Portugal, at
San Domingo, near the mouth of the Guadiana ; in Algeria, Turkey,
China, Japan, Cape of Good Hope ; in South Australia, where are
three prominent mines, the Burra, Wallaroo, and Moonta, their yield
in 1875, £451,500 ; New South Wales, the yield in 1875, about 6,000
tons, the value £508,800.
In South America, in Chili, in the vicinity of Copiapo, and less
abundantly at other places to the south ; in Bolivia, also in Peru, and
the Argentine Republic, but not much developed. In Cuba, but much
less productive than formerly.
In Eastern North America, some copper has been afforded by the
^Triassic of New Jersey and the Connecticut Valley, but there are no
'producing mines. Corinth, Vermont, and the Hiwassee mine, Ten-
nessee, are worked. The chief sources of copper are the veins of
Northern Michigan, near Lake Superior. The veins are connected with
trap-dikes intersecting a red Lower Silurian sandstone as stated on
page 131. The first discoveries of copper ore were made at Copper
Harbor. Near Fort Wilkins the black oxide was afterward found in a
large deposit, and 40,000 pounds of this ore were shipped to Boston.
On further exploration in the trap, the Cliff mine, 25 miles to the
westward, was laid open, where the largest masses of native copper
have been found, and which still proves to be highly productive.
Other veins have since been opened in various parts of the region, at
Eagle Harbor, Eagle River, Grand Marais, Lac La Belle, Agate Harbor,
Torch Lake, on the Ontonagon, in the Porcupine Mountains, and else-
where. The country north of Lakes Superior and Huron, IsLe Royale
and the Michipicotoii Islands, in Lake Superior, also afford copper ores,
and the vicinity of Quebec at the Acton and Harvey Hill mines, in rocks
referred to the Quebec formation.
In Western North America, in Arizona, there are large veins of
copper north of the Gila, on the borders of New Mexico, where are
the Santa Rita and Hanover mines, and the ores are cuprite, chalco-
cite, malachite ; there are rich veins also in Colorado, especially in
Gilpin and Park counties, in Nevada, and California.
The amount of copper produced in 1872, is stated as follows by
J. Arthur Phillips (Elements of Metallurgy) :
144 DESCRIPTIONS OF MINERALS.
England 5,600 tons.
Prussia 8,000
Russia 6,500
Hungary 3,500
Sweden and Norway 2,500
Spain 7,500
Portugal 5,500
Japan 1,000
South Australia 12,000
South Africa 7,500
Chili and Bolivia 46,500
United States 12,600
The total annual production is estimated by Phillips at 126,000 to
130,000 tons.
The metal copper was known in the earliest periods and was used
mostly alloyed with tin, forming bronze. The mines of Nubia and
Ethiopia are believed to have produced a great part of the copper of
the early Egyptians. Eubsea and Cyprus are also mentioned as afford-
ing this metal to the Greeks. It was employed for cutting instru-
ments and weapons, as well as for utensils ; and bronze chisels are at
this day found at the Egyptian stone-quarries, that were once em-
ployed in quarrying. This bronze (chalkos of the Greeks, and ces of
the Romans) consisted of about 5 parts of copper to 1 of tin, a propor-
tion which produces an alloy of maximum hardness. Nearly the
same material was used in early times over Europe ; and weapons and
tools have been found consisting of copper, edged with iron, indicating
the scarcity of the latter metal. Similar weapons have also been
found in Britain ; yet it is certain that iron and steel were well known
to the Romans and later Greeks, and to some extent used for warlike"
weapons and cutlery. Bronze is hardened by hammering or pressure.
Copper knives, axes, chisels, spear heads, bracelets, etc. , have been
found in the Indian Mounds of Wisconsin, Illinois, and the neighbor-
ing States ; and there is evidence that the Indians, besides using drift
masses of copper, knew of the copper veins of Northern Michigan, and
worked them, especially in the Ontonagon region, where their tools
and excavations have been discovered.
Copper at the present day is very various in its applications in the
arts. It is largely employed for utensils, for the sheathing of ships,
and for coinage. Alloyed with zinc it constitutes brass, and with tin
it forms bell-metal as well as bronze.
Brass consists of copper 65 per cent., zinc 35 ; with 53 '5 per cent, of
zinc the alloy is silver- white ; casting 'brass of 65-72 copper, 35-28
zinc ; or molu or Dutch metal, of 70-85 copper, 15-25 zinc, with 03 of
each, lead and tin ; brass for lathe-work of 60-70 copper, 28-38 zinc, 2
lead ; Muntz metal, for the sheathing of ships, 60 copper, 39 zinc,
1 lead ; spelter solder for brass, copper 50, zinc 50.
Bronze for medals consists of copper 93, tin 7 ; for speculum metal,
copper 60, tin 30, arsenic 10 ; for casting bronze, copper 82-83, tin 1-3,
zinc 17-18 ; for gun-metal, copper 85-92, tin 8-15 ; for bell-metal,
copper 65-80, tin 20-35, antimony 0-2 ; antique bronze, copper 67-95,
tin 8-15, lead 0-1, zinc 0-15.
Lord Rosse used for the speculum of his great telescope, 126 parts
ORES OF LEAD.
145
of copper to 57| parts of tin. The brothers Keller, celebrated for
their statue castings, used a metal consisting of 91 '4 per cent, of cop-
per, 5 '53 of zinc, 1/7 of tin, and 1/37 of lead. An equestrian statue of
Louis XIV., 21 feet high, and weighing 53,263 French pounds, was
cast by them in 1699, at a single jet.
An alloy of copper 90, and aluminum 10, is sometimes used in place
of bronze.
LEAD.
Lead occurs rarely native ; generally in combination with
sulphur ; also rarely with arsenic, tellurium, selenium, and
in the condition of sulphate, carbonate, phosphate and
arsenate, chromate and molybdate.
The ores of lead vary in specific gravity from 5*5-8-2,
They are soft, the hardness of the species with metallic lus-
tre not exceeding 3, and others not over 4. They are easily
fusible before the blowpipe (excepting plumbo-resinite) ; and
with soda on charcoal (and often alone), malleable lead may
be obtained. The lead often passes olf in yellow fumes,
when the mineral is heated on charcoal in the outer flame,
or it covers the charcoal with a yellow coating.
Native Lead.
A rare mineral, occurring in thin laminae or globules,
G. = 11-35. Said to have been seen in the lava of Madeira ;
at Alston in Cumberland with galena ; in the County of
Kerry, Ireland ; in an argillaceous rock at Carthagena ; at
Camp Creek, Montana.
Galenite. — Galena. Lead Sulphide.
Isometric. Cleavage cubic, eminent, and very easily ob-
tained. Also coarse or fine granular ; rarely fibrous.
1.
Color and streak lead- gray. Lustre shining metallic.
Fragile. H.=2-5. G. = 7'25-7-7.
146 DESCRIPTIONS OF MINERALS.
Composition. PbS= Sulphur 13-4, lead 86-6 = 100. Often
contains some silver sulphide, and is then called argentifer-
ous galena ; and at times zinc sulphide is present. The ore
of veins intersecting crystalline metamorphic rocks is most
likely to be argentiferous. The proportion of silver varies
greatly. In Europe, when it contains only 7 or 8 ounces
to the ton it is worked for the silver. The galenite of the
Hartz affords -03 to *05 per cent, of silver ; the English '02
to -03 per cent. ; that of Leadhills, Scotland, -03 to -06 ;
that of Pike's Peak, Colorado, '05 to -06; that of Arkan-
sas, -03 to -05 ; that of Middletown, Ct., 15 to -20 ; that of
Roxbury, Ct., 1*85 ; that of Monroe, Ct., 3*0 ; while that of
Missouri afforded Dr. Litton only '0012 to "002? per cent,
A little antimony or cadmium is sometimes present.
B.B. on charcoal, it decrepitates unless heated with cau-
tion, and fuses, giving off sulphur, coats the coal yellow,
and finally yields a globule of lead.
Diff. Galenite resembles some silver and copper ores in
color, but its cubical cleavage, or granular structure when
massive, will usually distinguish it. Its reactions before the
blowpipe show it to be a lead ore, and a sulphide.
Obs. Galena occurs in granite, limestone, argillaceous
and sandstone rocks, and is often associated with ores of
zinc, silver and copper. Quartz, barite, or calcite is gener-
ally the gangue of the ore ; also at times fluor spar. The
rich lead mines of Derbyshire and the northern districts of
England, occur in the Subcarboniferous limestone ; and the
same rock contains the valuable deposits of Bleiberg, in
Austria, and the neighboring deposits of Carinthia. The
ore of Cornwall is in true veins intersecting slates and is
argentiferous. At Freiberg in Saxony, it occupies veins in
gneiss ; in the Upper Hartz, and at Przibram in Bohemia,
it traverses clay slate, of Lower Silurian age ; at Sahla,
Sweden, it occurs in crystalline limestone. There are other
valuable beds of galena, in France at Poullaouen and Hue!
§oet, Brittany, and at Villefort, department of Lozere ; in
pain in the granite and argillyte hills of Linares, in Cata
Ionia, Grenada, and elsewhere ; in Savoy ; in Netherlands a
Yedrin, not far from Namur ; in Bohemia, southwest o
Prague ; in Joachimstahl, where the ore is worked princi
pally for its silver ; in Siberia in the Daouria Mountains in
limestone, argentiferous and worked for the silver.
The deposits of this ore in the United States are remark-
ORES OP LEAD.
ably for their extent. They occur in limestone, in the States
of Missouri, Illinois, Iowa, and Wisconsin ; argillaceous
iron ore, pyrite, calamine and smithsonite ("dry bone" of
the miners), blende ("black-jack"), carbonate of lead or
cerussite, and barite or heavy spar, are the most common
associated minerals ; and less abundantly occur chalcopy-
rite and malachite, ores of copper ; also occasionally the
lead ores, anglesite and pyromorphite ; and in the Mine La
Motte region, black cobalt, and linnaeite an ore of nickel.
Lead ore was first noticed in Missouri in 1700 and 1701.
In 1720 the mines were rediscovered by Francis Renault and
M. La Motte ; and the La Motte bears still the name of the
latter. Afterward the country passed into the hands of
Spaniards, and during that period, in 1763, a valuable mine
was opened by Francis Burton, since called Mine a Burton.
The lead region of Wisconsin, according to Dr. D. D.
Owen, comprises 62 townships in Wisconsin, 8 in Iowa, and
10 in Illinois, being 87 miles from east to west, and 54 miles
from north to south. The ore, as in Missouri, is abundant,
and throughout the region there is scarcely a square mile
in which traces of lead may not be found. The principal
indications in the eyes of miners, as stated by Mr. Owen,
are the following : fragments of calcite in the soil, unless
very abundant, which then indicate that the vein is wholly
calcareous or nearly so ; the red color of the soil on the sur-
face, arising from the ferruginous clay in which the lead is
often imbedded; fragments of lead ("gravel mineral"),
along with the crumbling magnesian limestone, and den-
dritic specks distributed over the rock; also, a depression of
the country, or an elevation, in a straight line ; or " sink-
holes ; " or a peculiarity of vegetation in a linear direction.
The ore, according to Whitney, occupies chambers or open-
ings in the limestone instead of true veins, and in this
respect it is like that of Derbyshire and Northern England.
The mines of Wisconsin and Illinois are in Lower Silurian
limestone of the Trenton period, called the Galena lime-
stone ; those of Southeastern Missouri, situated chiefly in
Franklin, Jefferson, Washington, St. Frangois, St. Gene-
vieve, and Madison counties, are in the " Third Magnesian
limestone ; " also Lower Silurian, but, of the Calciferous or
Potsdam period ; those of Southwestern Missouri, situated
mostly in Newtown, Jasper, Lawrence, Green and Dade
counties, and in the western part of McDonald, Barry,
DESCRIPTIONS OF MINERALS.
Stone, and Christian counties, are in the " Keokuk lime-
stone," of the Subcarboniferous period, but partly in Web-
ster, Taney, Christian, and Barry counties, in the Lower
Silurian "magnesian limestone;" those of Central Mis-
souri, situated in Moniteau, Cole, Miller, Morgan, and other
counties, are mostly in the Lower Silurian "magnesian
limestone," but partly, as in Northern Moniteau, in the Sub-
carboniferous. The conditions in which the ore occurs in
Missouri confirms the opinion of Prof. Whitney, as to there
being no true veins. Mr. Adolf Schmidt, in his account of
the Missouri lead ores, says that the deposits contain red
clay, broken chert, from the chert bed, and portions of the
limestone beds, along with the lead ; that the barite was in
troduced after the lead ; that some caves are filled througl
all their ramifications, while others arc only partly fille ~
and he adds that the same solvent waters that made the caves
and horizontal fissures or openings may have held the vari
ous minerals in solution. In Derbyshire, England, the de-
posits contain fossils of Permian rocks, showing that, al
though occurring in Subcarboniferous limestone, they wen
much later in origin.
Galenite also occurs in the region of Chocolate River anc
elsewhere, Lake Superior copper region ; on Thunder Bay
and Black Bay ; at Cave-in-Eock in Illinois, along with
fluorite ; in New York at Rossie, St. Lawrence County, in
gneiss, in a vein 3 to 4 feet wide ; near Wurtzboro' in Sul-
livan County, a large vein in millstone grit ; at Ancram,
Columbia County ; Martinsburg, Lewis County, N. Y., and
Lowville ; in Maine, at Lubec ; also of less interest at Blue
Hill Bay, Birmingham and Parsonsfield ; in New Hampshire,
at Eaton, Bath, Tamworth and Haverhill ; in Vermont, at
Thetford ; in Massachusetts, at Southampton, Leverett, and
Sterling, but without promise to the miner; at Newbury-
port, Mass., in a vein which is now worked ; at Middletown,
Ct., formerly worked as a silver-lead mine ; in Virginia, i
Wythe County, Louisa County, and elsewhere ; in Nort
Carolina, at King's Mine, Davidson County, where the lea
appears to be abundant ; in Tennessee, ab Brown's Creek
and at Haysboro', near Nashville ; in Pennsylvania, a
Phcenixville ; in Michipicoton and Spar Islands, Lake Supe-
rior. In Nevada it is abundant on Watkins River, and a
Steamboat Springs, Galena district ; in Colorado, at Pike's
Peak, etc.; in Arizona, in the Patagonian Mts., Santa Rita
ORES OF LEAD. 149
Mts., and in Yuma County; in the Castle Dome, Eureka,
and other districts, where the ore is worked for the silver it
contains.
The lead of commerce is obtained from this ore. It is
also employed in glazing common stoneware : for this pur-
pose it is ground up to an impalpable powder and mixed in
water with clay ; into this liquid the earthen vessel is dipped
and then baked.
Lead Selenides and Tellurides.
These various ores of lead are distinguished by the fumes before the
blowpipe, and by yielding, on charcoal, ultimately, a globule of lead.
Clausthalite, or lead selenide, has a lead-gray color, and granular
fracture, and is occasionally foliated. H.=2'5-3. G. =7-6-8*8. B.B. on
charcoal a horse-radish odor (that of selenium). From the Hartz.
There is a lead and copper selenide (Zorgite) which has the sp. gr.
7-7 '5. A lead-and-mercury selenide (Lehrbachite) occurs in foliated
grains or masses of a lead-gray to bluish and iron-black color.
Altaite, or lead telluride. A tin- white cleavable mineral, with H. =3
-3'5, and G. =816. From the Altai Mountains.
Nagyagite, or Foliated tellurium, is a less rare species, remarkable
for being foliated like graphite ; color and streak blackish lead-gray ;
H.=1-1'5. G. =7-085. It contains Tellurium 32*2, lead 54'0, gold 9'0,
with often silver, copper, and some sulphur. From Transylvania.
Antimonial and Arsenical Sulphides of lead. These include Sartorite,
Zinkenite, Plagionite, Jamesonite, Dufrenoysite, Boulangerite, Kobel-
lite, Meneghinite, Geocronite ; also Brongniardite and Freieslebenite,
in which silver is also present, and Stylotypite and Aikenite in which
copper is also present.
Minium. — Oxide of Lead.
Pulverulent. Color bright red, mixed with yellow. Gr. =
4 '6. Composition, Pb3 04. Affords globules of lead in the
reduction flame of the blowpipe.
Obs. Occurs at various mines, usually associated with
galena, and is found abundantly at Austin's Mines, Wythe
County, Virginia, with white lead ore.
Uses. Minium is the red lead of commerce ; but for the
arts it is artificially prepared.
Plumbic ochre is lead protoxide, of a yellow color.
Mendipite. Color white, yel>3wish or reddish, nearly opaque. Lustre
pearly. G. =7-7-1. PbCl2 + Pb 0= Chloride of lead 38 '4, lead oxide
61 6. From Mendip Hills, Somersetshire. Cotunnite is a chloride of
lead, Pb C12, occurring at Vesuvius in white acicular crystals. It con-
tains 74 -5 per cent, of lead.
Plumbogummite. In globular forms, having a lustre somewhat
like gum arable, and a yellowish or reddish-brown color. H. =4-4*5.
150 DESCRIPTIONS OF MINERALS.
G.— 6*3-6*4. Also a variety 4-4 -9. Consists of lead, alumina, and
water. From Huelgoet in Brittany, and at a lead mine in Beaujeu ;
also from the Missouri mines, with black cobalt, and from Canton
mine, Ga.
Anglesite. — Lead Sulphate.
Trimetric. In rhombic prisms
and other forms. Lateral cleavage.
/A 7= 103° 43 £'. Also massive ; la-
mellar or granular.
Color white or slightly gray or
green. Lustre adamantine ; some-
times a litte resinous or vitreous.
Transparent to nearly opaque. Brit-
tle. H. = .2-75-3. G. = G -1-6 -4.
Composition. Pb 0* S, affording
about 73 per cent, of oxide of lead.
PHCENIXVILLE. B. B. f uses in the flame of a candle,
and, on charcoal, yields lead with
soda.
Diff. Resembles aragonite and some other earthy species ;
but this and the other ores of lead are at once distinguished
by specific gravity, and also by their yielding lead in blow-
pipe trials. Differs from the carbonate of lead in lustre
and in not dissolving with effervescence in acid.
Obs. Usually associated with galena, and results from its
decomposition. Occurs in fine crystals at Leadhills and
Wanlockhead, Great Britain, and also at other foreign lead
mines. In the United States, it is found at the lead mines
of Missouri and Wisconsin ; in splendid crystallizations at
Phoenixville, Pa. ; sparingly at the Walton gold mine, Louisa
County, Va. ; at Southampton, Mass.; in Arizona, and in
Cerro Gordo, Cal.
Caledonite is a lead-and-copper sulphate, of azure-blue color. It is
remarkable for a very perfect cleavage in one direction. G.=6'4
From Leadhills and Roughten Gill, England; also from MinelaMotte,
Missouri.
Lead selenate. A sulphur-yellow mineral, occurring in small glob-
ules, and affording before the blowpipe on charcoal a garlic odor, and
finally a globule of lead. It is named Kerstenite.
Crocoite. — Crocoisite. Lead Chromate.
Monoclinic. In oblique rhombic prisms, massive, of a
bright red color and translucent. Streak orange-yellow.
G.=5-9-6-l.
ORES OF LEAD.
Composition. Pb 04 Cr= Chromium trioxide 31-1, lead
oxide 68-9. Blackens and fuses, and forms a shining slag
containing globules of lead.
Obs. Occurs in gneiss at Beresof in Siberia, and also in
Brazil. This is the chrome yellow of the painters.
Phcenicochroite (or Melanochroite) is another lead chromate, contain-
ing 23*0 of chromium trioxide, and having a dark red color ; streak
brick-red. Crystals usually tabular and reticulately arranged. G. =5'75.
From Siberia.
Vauquelinite, A lead and copper chromate, of a very dark green
or pearly black color, occurring usually in minute irregularly aggre-
gated crystals ; also reniform and massive. H. =2-5-3. G. =5*5-5 '8.
From Siberia and Brazil ; also at the lead mine near Sing Sing, in
mammillary concretions.
Stolzite, or lead tungstatc. In square octahedrons or prisms. Color
green, gray, brown, or red. Lustre resinous. H. =2*5-3. G.— 7'9-
81. Contains 51 of tungstic acid and 49 of lead.
Wulfenite, or lead molybdate. In dull-yellow octahedral crystals,
and also massive. Lustre resinous. Contains molybdenum trioxide
34*25, protoxide 64 '43. From Bleiberg and elsewhere in Carinthia ;
also Hungary. It has been found in small quantities in the Southamp-
ton lead mine, Mass. , and in fine crystals, at Phcenixville, Penn.
Lead SulpJialo-carbonates. There are two whitish or grayish ores
of this composition called Lanarkite and Leadhillite. The former con-
tains 71 per cent, of carbonate of lead ; the latter, 47.
Pyromorphite. — Lead Phosphate.
Hexagonal. In hexagonal prisms ; often
in crusts made of crystals. Also in globules
or reniform, with a radiated structure.
Color bright green to brown ; sometimes
fine orange-yellow, owing to an intermix-
ture with cfiromate of lead. Streak white
or nearly so. Lustre more or less resinous.
Nearly transparent to subtranslucent. Brit-
tle. H. =3-5-4. G. = 6-5-7 -1.
Composition. Pbs 08 P2 + £ Pb C12= Phos-
phorus pentoxide 15 '71, lead oxide 82-27, chlorine 2 -62
= 100-60. B.B. fuses easily in the forceps, coloring the
flame bluish green. On charcoal fuses, and on cooling,
the globule becomes angular ; the coal is coated white from
the chloride, and nearer the assay, yellow from lead oxide.
Soluble in nitric acid.
Diff. Has some resemblance to beryl and apatite ; but is
quite different in its action before the blowpipe, and much
higher in specific gravity.
152 DESCRIPTIONS OF MINERALS.
Obs. Leadhills, "Wanlockhead, and other lead mines of
Europe are foreign localities. In the United States, very
handsome crystallized specimens occur at King's Mine, in
Davidson County, N. C. ; other localities are the Perkiomen
and Phoenixville mines, Pa. ; the Lubec lead mines, Me. ;
Lenox, N. Y. ; formerly, a mile south of Sing Sing, N. Y. ;
and the Southampton lead mine, Mass.
The name pyromorpMte is from the Greek pur, fire, and
morplie, form, alluding to its crystallizing on cooling from
fusion before the blowpipe.
Mimetite. A lead arsenate, resembling pyromorphite in crystalliza-
tion, but giving a garlic odor on charcoal before the blowpipe. Color
pale yellow, passing into brown. H. =2*75-3*5. G. =6*41. Com-
position, Pb3O8 As7 + 14 PbCl2= Arsenic pentoxide 23*20, lead oxide
74*96, chlorine 2 *30 =100 '55. From Cornwall and elsewhere ; Phce-
nixville, Pa.
Hedyphane is a variety of mimetite containing much lime. It
occurs amorphous, of a whitish color, and adamantine lustre. H. =
3-5-4. G. =5-4-5 -5.
Karyinite. A lead arsenate containing manganese and calcium,
from Norway.
Ecdemite. A lead chloro-arsenate.
Vanadinite. A lead vanadate occurring in hexagonal prisms like
pyromorphite, and also in implanted globules. Color yellow to red-
dish brown. H. =2 -75-3. G. =6*6-7 '3. From Mexico; also from
Wanlockhead in Dumfriesshire.
Monimolite. A yellow lead antimonate.
Nadorite. A yellow lead chlor-antimonate.
Bindheimite. A hydrous lead antimonate.
Cerussite. — White Lead Ore. Lead Carbonate.
Trimetric. In modified right rhombic prisms, and often
in compound crystals, two or three crossing one another as
1. 2.
in fig. 2. /A 1=117° 13'. Also in six-sided prisms like
aragonite. Also massive ; rarely fibrous.
Color white, grayish, light or dark. Lustre adamantine.
Brittle. H. = 3-3 -5. G. = 6 46-6 -48.
LEAD. 153
Composition. Pb 03 0 = Carbon dioxide 16*5, lead oxide
83-5 = 100. B.B. decrepitates, fuses, and with care on char-
coal affords a globule of lead. Effervesces in dilute nitric
acid.
Diff. Like anglesite, distinguished from most of the spe-
cies it resembles by its specific gravity and yielding lead
when heated. From anglesite it differs in giving lead alone
before the blowpipe, as well as by its solution and efferves-
cence with nitric acid, and its less glassy lustre.
Obs. Associated usually with galena. Leadhills, Wan-
lockhead, and Cornwall have afforded splendid crystalliza-
tions ; also Linares, in Spain, and other lead mines on the
continent of Europe.
In the United States, handsome specimens are obtained
at Austin's Mines, Wythe County, Virginia, and at King's
Mine, in Davidson's County, North Carolina ; at the latter
place it has been worked for lead, and it is associated with
native silver and pyromorphite. Perkiomen and Phoenix-
ville, Penn., afford good crystals. It occurs also at "Vallee's
Diggings," Jefferson County, Missouri, and other mines, in
that State ; at Brigham's Mine, near the Blue Mounds,
Wisconsin, partly in stalactites ; at " Deep Diggings," in
crystals ; and at other places, both massive and in fine
crystallizations.
When abundant, this ore is wrought for lead. Large
quantities occur about the mines of the Mississippi Valley.
It was formerly buried up in the rubbish as useless, but it
has since been collected and smelted. It is an exceedingly
rich ore, affording in the pure state 75 per cent, of lead.
Carbonate of lead is the " white lead " of commerce, so
extensively used as a paint. The material for this purpose
is, however, artificially made.
Phosgenite or Corneous Lead. A cliloro-earbonate of lead, occurring
in whitish adamantine crystals. H.=r2*75-4. G. =6-6 31. Composi-
tion, Pb03 C+PbCl3. From Derbyshire and Germany.
Hydrocerussite. Hydrous lead carbonate. From Sweden.
Ganomal'te is a white lead-manganese silicate, affording 34 89 per
cent, of lead oxide. From Sweden. Hyalotccite is a lead-barium-lime
silicate. Both are from Longban, Sweden.
General Eemarks. — The lead of commerce is derived almost wholly
from the sulphide of lead or galenite, the localities of which have
already been mentioned. In some mining regions, the carbonate and
sulphate are abundant.
The lead mines of the Central United States afforded in 1826, 1,770
tons ; iu 1842, 17,340 tons ; and of late years, 12,000 to 15,000 tons.
154 DESCRIPTIONS OF MINERALS.
Nevada produced 10,000 tons in 1870, and 50,000 in 1875. According
to Phillips, England produced in 1872, (50,450 tons ; Prussia, in 1871,
49,500 tons ; Spain, in 1873, 102,600 tons ; France, 2,500 tons ; Italy,
15,500 tons ; Austria, 10,000 tons.
ZINC.
Zinc occurs in combination with sulphur and oxygen ;
and also in the condition of silicate, carbonate, sulphate,
and arsenate. It is also a constituent of one variety of the
species spinel. The chief sources of the metal are smith-
sonite or the carbonate ; willemite and calamine, or sili-
cates ; zincite, or the oxide ; sphalerite (blende), or the
sulphide ; and franklinite.
Sphalerite.— Blende. Zinc Sulphide.
Isometric. In dodecahedrons, octahedrons, and other allied
forms, with a perfect dodecahedral cleavage. Also massive ;
sometimes fibrous. Color wax-yellow, brownish-yellow, to
black, sometimes green, red and white ; streak white, to red-
dish brown. Lustre resinous or waxy, and brilliant on a
cleavage face ; sometimes submetallic. Transparent to sub-
translucent. Brittle. H.=3-5-4. G. =3 -9-4 '2. Some
specimens become electric with friction, and give off a yel-
low light when rubbed with a feather.
Composition. ZnS = Sulphur 33, zinc 67 = 100. Contains
frequently a portion of iron sulphide when dark colored ;
often also 1 or 2 per cent, of cadmium sulphide, especially
the red variety. Nearly infusible alone and with borax.
Dissolves in nitric acid, emitting sulphuretted hydrogen.
Strongly heated on charcoal yields fumes of zinc.
Diff. This ore is characterized by its waxy lustre, perfect
cleavage, and its being nearly infusible. Some dark varieties
look a little like tin ore, but their cleavage and inferior
hardness distinguish them ; and some clear red crystals,
ZINC. 155
which resemble garnet, are distinguished by the same char-
aracters and also by their very difficult fusibility.
Obs. Occurs in rocks of all ages, and is associated gener-
ally with ores of lead ; often also with copper, iron, tin, and
silver ores. The lead mines of Missouri and Wisconsin afford
this ore abundantly. Other localities are in Maine, at Lu-
bec, Bingham, Dexter, Parsonsfield ; in New Hampshire,
at Eaton, Warren, Haverhill, Shelburne ; in Vermont, at
Hatfield ; in Connecticut, in Brooktield, Berlin, Roxbury,
and Monroe ; in New York, at Ancram lead mine, the
Wurtzboro' lead vein, at Lockport, Root, 2 miles southeast
of Spraker's Basin, in Fowler, at Clinton ; at Franklin, N.
J., colorless (Cleiophane) ; in Pennsylvania, at the Perkio-
men lead mine ; in Virginia, at Austin's lead mine, Wythe
County; in Tennessee, near Powell's River, and at Haysboro';
at Prince's Mine, Spar Island, Lake Superior, with ores of sil-
ver ; in Beauce Co., Canada, where it is slightly auriferous.
This ore is the Black-jack of miners.
Blende is a useful ore of zinc, though more difficult of re-
duction than calamine. By its decomposition (like that of
pyrite), it affords sulphate of zinc or white vitriol.
Wurtzlte is zinc sulphide in hexagonal crystals from Bolivia. Huas-
colite and Youngite are zinc-lead sulphides.
Zincite,— Red Zinc Ore. Red Zinc Oxide.
Hexagonal. Usually in foliated masses, or in disseminated
grains ; cleavage eminent, nearly like that of mica ; but the
laminae brittle, and not so easily separable.
Color deep or bright red ; streak orange-yellow. Lustre
brilliant, subadamantine. Translucent or subtranslucent.
H. =4-4-5. G. =5-4-5 -7. Thin scales by transmitted light
deep yellow.
Composition. Zn 0 = Oxygen 19-7, zinc 80-3 = 100. B.B.
infusible alone, but yields a yellow transparent glass with
borax ; on charcoal, a coating of zinc oxide. Dissolves in
nitric acid without effervescence.
Diff. Resembles red stilbite, but distinguished by its in-
fusibility and also by its mineral associations.
Obs. Occurs witli franklinite at Mine Hill and Sterling
Hill, Sussex County, N. J.
A good ore of zinc, and easily reduced.
Voltzite. A compound of sulphur, oxygen and zinc, 4 Zn S +Zn O.
Occurs in implanted globules of a dirty rose-red color, with a pearly
lustre on a cleavage surface. From France, and near Joachimstahl.
156 DESCRIPTIONS OP MINERALS.
Goslarite.— Sulphate of Zinc. White Vitriol.
Trimetric. Cleavage perfect in one direction. / A /=
90° 42'.
Color white. Lustre vitreous. Easily soluble ; taste as-
tringent, metallic, and nauseous. Brittle. H. =2-2-5. G.=
1-9-2-1.
Composition. Zn04S + 7 aq. =Zinc oxide 28-2, sulphur
trioxide 27*9, water 43-9 = 100. B.B. gives off fumes of
zinc on charcoal, which cover the coal.
Obs. Eesults from the decomposition of blende. Occurs
in the Hartz, in Hungary, in Sweden, and at Holywell in
Wales.
Sulphate of zinc is extensively employed in medicine and
dyeing. For these purposes it is prepared to a large extent
from blende by decomposition, though this affords, owing to
its impurities, an impure sulphate. It is also obtained by
direct combination of zinc with sulphuric acid.
White Vitriol, as the term is used in the arts, is one form
of sulphate of zinc, made by melting the crystallized sul-
phate, and agitating till it cools and presents an appearance
.like loaf sugar.
Kottigite. A hydrous zinc-cobalt arsenate of reddish color (owing
to presence of cobalt) from Schneeberg
Adamite. A hydrous zinc-arsenate of honey -yellow to violet color,
from Chili.
Smithsonite. — Carbonate of Zinc.
Ehombohedral. R A 72=107° 40'. Cleavage R perfect.
Massive or incrusting ; reniform and stalactitic.
Color impure white, sometimes green or brown ; streak
uncolored. Lustre vitreous or pearly. Subtransparent to
translucent. Brittle. H.=5. G. =4-3-4-45.
Composition. Zn03C = Carbon dioxide 35 -2, zinc oxide
64-8 (four-fifths of which is pure zinc) = 100. Often con-
tains some cadmium. B.B. infusible alone, but carbonic
xicid and oxide of zinc are finally vaporized. Effervesces in
nitric acid. Negatively electric by friction.
Diff. The effervescence with acids distinguishes this
mineral from the following species ; and the hardness, diffi-
cult fusibility, and the zinc fumes before the blowpipe, from
the carbonate of lead or other carbonates. Besides, the
crystals over a drusy surface terminate usually in sharp
three-sided pyramids.
ZINC. 157
Obs. Occurs commonly with galena or blende, and usual-
ly in calcareous rocks. Found in Siberia, Hungary, Sile-
sia ; at Bleiberg in Carinthia ; near Aix-la-Chapelle in the
Lower Rhine, and largely in Derbyshire and elsewhere in
England. In the United States, it is abundant at Vallee's
Diggings in Missouri, and at other lead " diggings" in Iowa
and Wisconsin ; also in Claiborne County, Tenn. Sparingly
also at Hamburg, near the Franklin Furnace, N. J. ; at the
Perkiomen lead mine, Pa., and at a lead mine in Lancaster
County.
Hydrozincite is a hydrous zinc carbonate, ZnO3 C+ 2 Zn02H, of a
whitish color, with G.=3'58-3'8.
Aurichaldte is a hydrous carbonate of zinc and copper, occurring in
drusy incrustations of acicular crystals, having a pale verdigris-green
color. From Siberia, Hungary, England, and Lancaster, Pa.
Buratite is a liine aurichalcite.
Willemite.— Zinc Silicate. Troostite.
Ehombohedral. R A 72=116° 1'. In hexagonal prisms,
and also massive.
Color whitish, greenish yellow, apple-green, flesh-red, yel-
lowish brown. Streak uncolored. Transparent to opaque.
Brittle. H.=:5-5, G.=3-89-4-18.
Composition. Zn 03 Si = Silica 27*1, zinc oxide 72 '9 =
100. B.B. fuses with difficulty to a white enamel ; on char-
coal, and most easily on adding soda, yields a coating which is
yellow while hot, and white on cooling, and which, moistened
with cobalt solution and treated in O.F., is colored bright
green. Gelatinizes with hydrochloric acid.
Obs. From Moresnet, between Liege and Aix-la-Chapelle ;
Raibel in Carinthia ; Greenland. Abundant at both Frank-
lin and Sterling, mixed with zincite, and used as an ore of
zinc ; also in prismatic crystals that occasionally are six inches
long.
Calamine. — Hydrous Zinc Silicate. Galmei.
Trimetric. In rhombic prisms, the opposite extremities
with unlike planes. / A /=104° 13'. Cleavage perfect
parallel to /. Also massive and inerusting, mammillated or
stalactitic.
Color whitish or white, sometimes bluish, greenish, or
brownish. Streak uncolored. Transparent to translucent.
Lustre vitreous or subpearly. Brittle. H.=4'5-5. Gr. =•
3-16-3*9. Pyro-electric.
158 DESCRIPTIONS OP MINERALS.
Composition. Zn2 04 Si + aq. = Silica 25'0, zinc oxide 67'5,
water 7'5 = 100.
B.B. alone it is almost infusible. Forms a clear glass
with borax. In heated sulphuric acid it dissolves, and the
solution gelatinizes on cooling.
Diff. Differs from calcite and aragonite by its action with
acids ; from a salt of lead, or any zeolite, by its infusibility ;
from chalcedony by its inferior hardness, and its gelatiniz-
ing with heated sulphuric acid ; and from smithsonite by
not effervescing with acids, and by the rectangular aspect of
its crystals over a drusy surface.
Obs. Occurs with calamine. In the United States it is
found at Vallee's Diggings, Mo.; at the Perkiomen and
Pho3nixville lead mines ; on the Susquehanna, opposite
Selinsgrove ; at Friedensville in Saucon Valley, two miles
from Bethlehem, Pa,, with massive blende. Abundantly at
Austin's Mines, Wythe County, Va. Valuable as an ore of zinc.
Hopeite is a rare mineral occurring in grayish-white crystals or mas-
sive, with calamine, and supposed to be a hydrous zinc-phosphate.
Franklinite, an ore of iron, manganese and zinc, is described under
iron, on page 179.
General Remarks. — The metal zinc (spelter of commerce) is supposed
to have been unknown in the metallic state to the Greeks and Romans.
It has been long worked in China, and was formerly imported in large
quantities by the East India Company.
The principal mining regions of zinc in the world arc in Upper Sile-
sia, at Tarnowitz and elsewhere ; in Poland ; in Carinthia, at Eaibel and
Bleiberg ; in Netherlands at Llmberg ; at Altenberg, near Aix-la-
Chapelle in the Prussian province of the Lower Rhine ; in England,
in Derbyshire, Alstonmoor, Mendip Hills, etc. ; in the Altai in Eussia ;
besides others in China, of which little is known. In the United
States, smithsonite and calamine occur with the lead of the West in
large quantities. They were formerly considered worthless and thrown
aside, under the name of " dry bone." In Tennessee, Claihorne
County, there are workable mines of the same ores. Calamine occurs
at Friedensville, Pennsylvania, along with massive blende : the bed
has been, but is not now worked. The zincite, willemite, and frank-
linite of Franklin, New Jersey, are together worked as a zinc ore,
and both zinc and zinc oxide are produced. Blende is sufficiently abun-
dant to be worked at the Wurtzboro' lead mine, Sullivan County, New
York ; at Eaton and Warren, in New Hampshire : at Lubec, in Maine ;
at Austin's Mine, Wythe County, Virginia, and at some of the Missouri
lead mines.
The amount of zinc produced in 1872, in Europe, was about 45,745
tons for Belgium ; 55,744 for Germany ; 3,000 for Austria : 15,000 for
Great Britain ; 4,400 for France ; 4,400 for Spain : making the total
amount 128,289 tons. In the United States the amount of zinc made
in 1875 was about 15,000 tons ; of zinc oxide, 8,500 tons.
TIN. 159
Zinc is a brittle metal, but admits of being rolled into sheets when
heated to about 21 2° F. In sheets it is extensively used for roofing
and other purposes, it being of more difficult corrosion, much harder,
and also very much lighter than lead. It is also employed largely for
coating (that is, making what is called galvariized) iron. Its alloys with
copper (page 144) are of great importance.
The white oxide of zinc is much used for white paint, in place of
white lead ; and also in making a glass for optical purposes.
An impure oxide of zinc, called cadmia, often collects in large quan-
tities in the flues of iron and other furnaces, derived from ores of zinc
mixed with the ores undergoing reduction. A mass weighing 600
pounds was taken from a furnace at Bennington, Vt. It has been ob-
served in the Salisbury iron furnace, and at Ancram, in New Jersey,
where it was formerly called Ancramite.
CADMIUM.
There is but a single known ore of this rare metal. It is
a sulphide, and is called Greenockite. It occurs in hexagonal
prisms, with dissimilar pyramidal termination, of a light
yellow color, high lustre, and nearly transparent. H. =3-
3-5. G. =4-8-5. From Bishopton, Scotland.
Cadmium is often associated with zinc in sphalerite and
calamine. The cadmiferous sphalerite is called Przibramite.
The metal cadmium is white like tin, and is so soft that
it leaves a trace upon paper. It fuses at 442° F. It was
discovered by Stromeyer in 1818.
TIN.
Tin has been reported as occurring native in the gold
washings of the Ural, and in Bolivia. There are two ores,
a sulphide and an oxide. It also occurs in some ores of
columbium, tantalum, and tungsten.
•
Stannite.— Tin Pyrites, Sulphuret of Tin. Tin Sulphide.
Commonly massive, or in grains. Color sfceel-gray to iron-
black ; streak blackish. Brittle. H.=4. G. =4-3-4 -6.
Composition. Sulphur 30, tin 27, copper 30, iron 13 = 100.
Obs. From Cornwall, where it is often called lell-metal
ore? from its frequent bronze appearance ; also from Ireland
and the Erzgebirge.
160
DESCRIPTIONS OF "MINERALS.
Cassiterite.— Tin Ore. Tin Oxide.
Dimetric.
1.
In square prisms and octahedrons; often com-
2.
pounded. 1 A 1 = 121° 40' ; 1 i
Al i (over the summit) 112°
10', (over a terminal edge)
133° 31'. Cleavage indistinct.
Also massive, and in grains.
Color brown or black, with .
a high adamantine lustre when
in crystals. Streak pale gray
to brownish. Nearly trans-
parent to opaque. H.=6-7. G.= 6-4-7-1.
Composition. Sn 02= Oxygen 21*33, tin 78-67 ; often con-
tains a little iron, and sometimes tantalum.
B.B. alone infusible. On charcoal with soda, affords a
-globule of tin.
Stream tin is the gravel-like ore found in debris in low
grounds. Wood tin occurs in botryoidal and reniform shapes
with a concentric and radiated structure ; and toads-eye tin
is the same on a small scale.
Diff. Tin ore has some resemblance to a dark garnet, to
black zinc blende, and to some varieties of tourmaline. It is
distinguished by its infusibility, and its yielding tin before
the blowpipe on charcoal with soda. It differs from blende
also in its superior hardness.
Obs. Tin ore occurs in veins in the crystalline rocks,
granite, gneiss, and mica slate, associated often with wolfram,
copper and iron pyrites, topaz, tourmaline, mica or talc, and
albite. Cornwall is one of its most productive localities.
It is also worked in Saxony, at Altenberg, Geyer, Ehren-
friedersdorf and Zinnwald; in Austria, at Schlackenwald and
other places ; in Malacca, Pegu, China, and especially the
Island of Banca in the East Indies ; in Queensland and
Northern New South Wales, Australia, in large quantities ;
in Greenland. It occurs* also in Galicia, Spain ; at Dale-
carlia in Sweden ; in Russia ; in Mexico at Durango;
and Bolivia. In the United States it has been found spar-
ingly at Chesterfield and Goshen, Mass.; in some of the Vir-
ginia goldmines ; in Lyme and Jackson, N. H. ; and in the
Temescal Range, California.
General Remarks. — The principal tin mines now worked, are those
of Cornwall, Banca, Malacca, and Australia.
The Cornwall mines were worked long before the Christian era.
TIN. 161
Herodotus, 450 years before Christ, is believed to allude to the tin
islands of Britain under the cabalistic name Cassiterides, derived from
the Greek kassiteros, signifying tin. The Phoenicians are allowed to
have traded with Cornubia (as Cornwall was called, it is supposed
from the horn-like shape of this extremity of England). The Greeks
residing at Marseilles were the next to visit Cornwall, or the isles ad-
jacent, to purchase tin ; and after them came the Romans, whose
merchants were long foiled in their attempts to discover the tin market
of their predecessors.
Camdeu says : " It is plain that the ancient Britons dealt in tin mines
from the testimony of Diodorus Siculus, who lived in the reign of
Augustus, and Timaus, the historian in Pliny, who tells TIS that the
Britons fetched tin out of the Isle of Icta (the Isle of Wight), in their
little wicker boats covered with leather. The import of the passage
in Diodorus is that the Britons who lived in those parts dug tin out of
a rocky sort of ground, and carried it in carts at low water to certain
neighboring islands ; and that from thence the merchants first trans-
ported it to Gaul, and afterwards on horseback in thirty days to the
springs of Eridanus, or the city of Narbona, as to a common mart.
JEthicus too, another ancient writer, intimates the same thing, and
adds that he had himself given directions to the workmen." In the
opinion of the learned author of the Britannica here quoted, and others
who have followed him, the Saxons seem not to have meddled with
the mines, or, according to tradition, to have employed the Saracens ;
for the inhabitants of Cornwall to this day call a mine that is given
over working Attal-Sarasin, that is, the leavings of the Saracens.
The Cornwall veins, or lodes, mostly run east and west, with a dip
— hade, in the provincial dialect — varying from north to south ; yet
they are very irregular, sometimes crossing each other, and sometimes
a promising vein abruptly narrows or disappears ; or again they spread
out into a kind of bed or floor. The veins are considered worth work-
ing when but three inches wide. The gangue is mostly quartz, with
some chlorite. Much of the tin is also obtained from beds of loose
stones or gravel (called sh'tdes^, and courses of such gravel or tin de-
bris are called streams, whence the name stream tin.
The Australian mines are mainly in the New England district of
Northern New South Wales, and the adjoining part of Queensland, and
a large part of the ore goes north through Queensland. The value of
the tin exported in 1875 from Queensland was £88,2*24, and from New
South Wales (Ann. Rep. Dept. of N. S. W. Mines, 1876), £561,311, cor,
responding to 6,058 tons of tin in ingots, besides 2,0?2 tons of ore.
The value of all the tin raised in N. S. Wales, prior to 1875 is £866,461.
Beechwood, Victoria, also affords a little tin.
The annual production of tin in 1871 in Great Britain was 11,320
tons, and in Banca and Malacca, 7,500.
Tin is used in castings, and also for coating other metals, especially
iron and copper. Copper vessels thus coated were in use among the
Romans, though not common. Pliny says that the tinned articles
could scarcely be distinguished from silver, and his use of the words
incoquere and incoctilia seems to imply, as a writer states, that the
process was the same as for the iron wares of the present day, by im-
mersing the vessels in melted tin. Its alloys with copper are mentioned
on page 144.
162 DESCRIPTIONS OF MINERALS.
Tin is also used extensively as tinfoil ; but most tinfoil consists be*
neath the surface of lead, and is made by rolling out plates of lead coated
with tin. With quicksilver it is used to cover glass in the manufac-
ture of mirrors. Tin oxide (dioxide), obtained by chemical processes,
is employed, on account of its hardness, in making a paste for sharp-
ening fine cutting instruments, and also to some extent in the prepara.
tion of enamels. The chlorides of tin are important in the precipita-
tion of many colors as lakes, and in fixing and changing colors in dye-
ing and calico-printing. The bisulphide has a golden lustre, and wa^
termed aurum musivum, or mosaic gold, by the alchemists. It ismucr
used for ornamental painting, for paper-hangings and other purposes,
under the name of bronze powder.
TITANIUM.
Titanium occurs in nature combined with oxygen, form-
ing titanium dioxide or titanic acid, and also in oxygen com-
binations with iron and calcium, and in some silicates. It
has not been met with native.
The ores are infusible alone before the blowpipe, or nearly
so. Their specific gravity is between 3-0 and 4-5.
Rutile.
Dimetric. In prisms of four, eight, or more sides, with
pyramidal terminations, and often bent as in
the figure; lAl = 123° 7J'. Crystals often
acicular, and penetrating quartz. Some-
times massive. Cleavage lateral, somewhat
distinct.
Color reddish-brown to nearly red ; streak
very pale brown. Lustre submetallic-ada-
mantine. Transparent to opaque. Brittle.
H. =6-6-5. G. =4-15-4 -25.
Composition. Ti 02 = Oxygen 39, titanium 61 = 100.
Sometimes contains iron, and lias nearly a black color ; this
variety is called Nigrine. B.B. alone unaltered ; with salt
of phosphorus a colorless bead, which in the reducing flame
becomes violet on cooling.
Diff. The peculiar subdamantine lustre of rutile, and
brownish-red color, much lighter red in splinters, are striking
characters. It differs from tourmaline, idocrase, and augite,
by being unaltered when heated alone before the blowpipe ;
and from tin ore, in not affording tin with soda ; from
ephene in its crystals.
COBALT AND NICKEL. 163
Obs. Occurs imbedded in granite, gneiss, mica schist sye-
nyte, and in granular limestone. Sometimes associated with
hematite, as at the Grisons. Yrieix in France, Castile,
Brazil, and Arendal in Norway, are some of the foreign
localities.
In the United States, it occurs in crystals in Maine, at
"Warren ; in New Hampshire, at Lyme and Hanover ; in
Massachusetts, at Barre, Windsor, Shelburne, Leyden, Con-
way ; in Connecticut, at Monroe and Hunting-ton ; in New
York, near Edenville, Warwick, Amity, at Kingsbridge, and
in Essex County at Gouverneur ; in Pennsylvania, in Chester
County ; in the District of Columbia, at Georgetown ; in
North Carolina, in Buncombe County ; in Georgia, in Lin-
coln and Ilabersham counties ; at Magnet Cove in Arkansas.
The specimens of limpid quartz, penetrated by long aci-
cular crystals, are often very handsome when polished. A re-
markable specimen of this kind was obtained in Northern
Vermont, and less handsome ones are not uncommon ; they
are found in North Carolina. Polished stones of this kind
are c&Ned. fleches (T amour (love's arrows) by the French.
This ore is employed in painting on porcelain, and quite
largely for giving the requisite shade of color and enamel
appearance to artificial teeth.
Octahedrite (Anatase) ; Brookite. These species have the same com-
position as rutile. Octahedrite occurs in slender nearly transparent
octahedrons, of a brown color. lAl=97° 51'. H. = 5'5-6. G.=3'8-
3-95. From Dauphiny, the Tyrol, and Brazil ; at Smithfield, R. I.
Brookite is met with in thin hair-brown flat trimetric crystals, at-
tached by one edge. Also in thick iron-black crystals, as in the va-
riety called Arkansite. H. — 5 '5-6. From Dauphiny; Snowdon in
Wales ; Ellenville, Ulster County, N. Y. ; Paris, Maine ; gold wash-
ings of North Carolina ; Magnet Cove, Arkansas (Arkansite).
Perofskite. In cubic crystals, of yellow, brown, and black colors ;
chemical formula (Ti, Ca)a O3. From the Urals, the Tyrol, and Magnet
Cove, Arkansas.
Besides the ores here described, titanium is an essential constituent
also of ilmenite (titanic iron), and of the silicates titanite or sphene
(p. 290), keilliauite (p. 291), wanoickite ; and occurs also in the zir-
conia and yttria ores ceschynite, cerstcditc, and polymignite, and in some
other rare species ; sometimes in pyrochlore.
COBALT, NICKEL.
Cobalt has not been found native. The ores of cobalt
are sulphides, arsenides, arseno-sulphides, an oxide, a car-
bonate, a phosphate, and an arsenate; and nickel is often
164 DESCRIPTIONS OP MINERALS.
associated with cobalt in the sulphides and arsenides. The
ores having a metallic lustre vary in specific gravity from
6 -2 to 7 '2 ; and the color is nearly tin-white or pale steel,
gray, inclined to copper-red. The ores without a metallic
lustre have a clear red or reddish color, and specific gravity
of nearly 3. Cobalt is often present also in arsenopyrite (or
mispickel), and sometimes in pyrite.
The ores of nickel are sulphides, arsenides, arseno-sulph-
ides, and anti mono-sulphides, a sulphate, carbonate, silicates,
arsenate ; and the metal is a constituent of several cobalt
ores, and also often of pyrrhotite (magnetic pyrites). Specific
gravity between 3 and 8 ; hardness of one 3, but mostly be-
tween 5 and 6. Those of metallic lustre resemble some cobalt
ores ; but they do not give a deep blue color with borax.
Linnaeite.— Cobalt Sulphide. Cobalt and Nickel Sulphide.
Isometric. In octahedrons and cubo-octahedrons ; also
massive. Color pale steel-gray, tarnishing copper red. Streak
blackish gray. H. = 5 -5. G. = 4 -8-5.
Composition. Co3 S4 = Sulphur 42 -0, cobalt 5 -80 = 100 ; but
with part of the cobalt replaced by nickel ; copper some-
times present. Siegenite is a variety containing 30 to 40 per
cent, of nickel. B.B. on charcoal yields sulphurous odor
and a magnetic globule ; often also arsenical fumes.
Obs. From Sweden, Prussia ; Mine la Motte in Missouri
(Siegenite) ; Mineral Hill in Maryland. Sometimes called
cobalt pyrites.
Millerite.— Nickel Sulphide. Capillary Pyrites.
Ehombohedral. Usually in capillary or needle-like crys"
tallizations ; sometimes like wool. Also in columnar crusts
and radiated. Color brass-yellow, inclining to bronze-yellow,
with often a gray iridescent tarnish. Streak bright. Brittle.
H.=3-3-5. G. =4-6-5 -65.
Composition. Ni S = Sulphur 35-6, nickel 64-4=100. In
the open tube sulphurous fumes. B.B. on charcoal fuses
to a globule ; and after roasting, gives, with borax and salt of
phosphorus, a violet bead in O.F., which in K.F. becomes
gray from reduced metallic nickel.
COBALT AND NICKEL. 165
Obs. From Joachimstahl, Przibram, Kiechelsdorf ; Sax-
ony ; Cornwall ; at the Sterling Mine, Antwerp, N. Y.; at
the Gap Mine, Lancaster Co., Pa.; at St. Louis, Mo., in
capillary forms, and sometimes wool-like, in cavities in mag-
nesian limestone. A valuable ore of nickel.
Beyrichite has the formula Ni5 S7.
Smaltite. — Cobalt Glance. Chloanthite.
Isometric. Occurs in octahedrons, cubes, and dodecahe-
drons, and other forms. See figs. 1, 2, 3, page 17, and 17, 27,
page 20. Cleavage octahedral, somewhat distinct. Also
reticulated ; often massive.
Color tin-white, sometimes inclining to steel-gray. Streak
grayish black. Brittle. Fracture granular and uneven.
Composition. (Co, Ni) As2 ; the ore being either a cobalt
arsenide, or cobalt-nickel arsenide ; and graduating into the
nickel arsenide called Chloanthite. The cobalt in the ore
may constitute 23*5 per cent. ; but it may be wholly absent
as in the chloanthite. In addition, iron often replaces part
of the other metals, as in the variety Safflorite.
In the closed tube gives a sublimate of metallic arsenic ;
in the open tube a white sublimate of arsenous oxide, and
sometimes traces of sulphurous acid. B.B. on charcoal,
affords an arsenical odor, fuses to a globule which gives re-
action for iron, cobalt, and nickel.
Diff. Arsenopyrite (mispickel) has tho white color of
smaltite, but it yields sulphur as well as arsenic, and in a
closed tube affords arsenic sulphide, orpiment and realgar.
Obs. Usually in veins with ores of cobalt, silver, and
copper. Occurs in Saxony, especially at Schneeberg ; also
in Bohemia, Hessia, and Cornwall.
In the United States it is found in gneiss with copper
nickel (niccolite), at Chatham, Conn.
Cobaltite.
Isometric. Crystals like those of pyrite, but silver-white
in color with a tinge of red, or inclined to steel-gray. Streak
grayish black. Brittle. H. = 5 -5. G. = 6 -63.
Composition. CoS2 + Co As2= Co AsS = Arsenic 45-2, sul-
phur 19-3, cobalt 35-5 = 100, but often with much iron
and occasionally a little copper. Unaltered in the closed
16(> DESCRIPTIONS OF MINERALS.
tube ; but in the open tube, yields sulphurous fumes and a
white sublimate of arsenous oxide. B.B. on charcoal yields
sulphur and arsenic and a magnetic globule ; with borax a
cobalt-blue globule.
Diff. Unlike smaltite affords sulphur, and has a reddish
tinge in its white color.
Obs. From Sweden, Norway, Siberia, and Cornwall.
Most abundant in the mines of Wehna in Sweden, first
opened in 1809.
Niccolite.— Copper Nickel. Arsenical Nickel.
Hexagonal. Usually massive. Color pale copper-red.
Streak pale brownish-red. Lustre metallic. Brittle. H. =
5-5-5. G. = 7-3-7-7.
Corn-position. Ni As— Nickel 44, and arsenic 56 ; some-
times part of the arsenic is replaced by antimony. Gives off
arsenical (alliaceous) fumes before the blowpipe, and fuses to
a pale globule, which darkens on exposure. Assumes a
green coating in nitric acid, and is dissolved in aqua-regia.
Diff. Distinguished from pyrite and linnaeite by its pale
reddish shade of color, and also its arsenical fumes, and
from much of the latter by not giving a blue color with
borax. None of the ores of silver with a metallic lustre
have a pale color, excepting native silver itself.
Obs. Accompanies cobalt, silver, and copper ores in the
mines of Saxony, and other parts of Europe ; also sparingly
in Cornwall.
It is found at Chatham, Conn., in gneiss, associated with
white nickel or cloanthite.
Skutterudite. A cobalt arsenide of the formula Co As3, from Skut-
terud, Norway.
Breithauptite or Antimonicd Nickel. Ni Sb= Antimony 67 '8, nickel
32-2 = 100. It has a pale copper-red color, inclining to violet. H.— 5'5
-6. G.=7'54 Crystals hexagonal. From Andreasberg.
Gersdorffite. A nickel arsenosulphide ; NiS2 + Ni As2=:Ni AsS=
Arsenic 45 '5, sulphur 19 '4, nickel 35 •!, but varying much in composi-
tion. Color sulphur- white to steel-gray. H. =5'5. G.=5'6-6-9.
Ullmatmite or Nickel Stibine. An antimonial nickel sulphide, con-
taining 25 to 28 per cent, of nickel. Color steel-gray, inclining to sil-
ver-white. In cubical crystals, and also massive. H.=:5-5'5. G. =6'45.
From the Duchy of Nassau.
Grunauite or Bismuth Nickel. A sulphide containing 31 to 38*5 of
sulphur, 10 to 14 per cent, of bismuth, with 22 to 40 '7 of nickel.
Color light steel --gray to silver- white ; often tarnished yellowish. H. =
4-5. G. =5-13. From the district of Altenkirchen, Prussia.
COBALT AND NICKEL. 167
Asbolite.— Earthy Cobalt. Black Cobalt Oxide.
Earthy, massive. Color black or blue-black. Soluble in
muriatic acid, with an evolution of fumes of chlorine.
Obs. Occurs in an earthy state mixed with oxide of man-
ganese as a bog ore, or secondary product. Abundant at
Mine La Motte, Missouri, and also near Silver Bluff, South
Carolina. The analyses vary in the proportion of oxide of
cobalt associated with the manganese, as the compound is a
mere mixture. Sulphide of cobalt occurs with the oxide.
The Carolina ores afforded Cobalt oxide 24, manganese
oxide 76. The ore from Missouri, as analyzed by Prof.
Silliman, afforded 40 per cent, of cobalt oxide, with oxides
of nickel, manganese, iron and copper.
This ore has been found abroad in France, Germany,
Austria, and England.
The ore is purified and made into smalt, for the arts.
Erythrite. — Cobalt Bloom. Hydrous Cobalt Arsenate.
Monoclinic. In oblique crystals having a highly perfect
cleavage, like mica ; laminae flexible in one direction. Also
as an incrustation, and in reniform shapes, sometimes stel-
late.
Color, peach-red, crimson-red, rarely grayish or greenish ;
streak a little paler, the dry powder lavender-blue. Lustre
of laminae pearly ; earthy varieties without lustre. Trans-
parent to subtranslu cent. H. — 1 '5-2. G. = 2. 95.
Composition. Co308As2 + 8aq = Arsenic acid 38-4, oxide
of cobalt 37 -6, water 24-6. B.B. on charcoal gives arsen-
ical fumes and fuses ; yields a blue glass with borax.
The earthy ore is sometimes called peach-blossom ore, from
its color; and also red cobalt, ochre. Kottigite is a kind
containing zinc.
Diff. Eesembles red antimony, but that species wholly
volatilizes before the blowpipe. From red copper ore it
differs in giving a blue glass with borax ; moreover, the
color of the copper ore is more sombre.
Obs. Occurs with ores of lead and silver, and other co-
balt ores. Schneeberg, in Saxony; Saalfield, in Thuringia ;
and Riechelsdorf, in Hessia, are noted European localities.
It is found also in Dauphiny, Cornwall, and Cumberland.
Valuable as an ore of cobalt when abundant.
168 DESCRIPTIONS OF MINERALS.
Roselite is a rose-red triclinic arsenate of cobalt.
Bieberite or Cobalt Vitriol. Has a flesh-red or rose-red tint, and
astringent taste. Co 04 S + 7aq = Sulphuric acid 28 '4, cobalt oxide
25'5, water 461.
Morenosite. A nickel vitriol, Ni O4 S + 7aq, having apple-green to
greenish- white color. Lindackerite, hydrous nickel -copper arsenate.
Zaratite or Emerald Nickel. Incrusting, minute globular or stalac-
titic. Color bright emerald-green. Lustre vitreous. Transparent or
nearly so. H. =;3-3'25. G. — 2'5-2'7. It is a nickel carbonate, con-
taining nearly 30 per cent, of water. B.B. infusible alone, but loses
its color. Occurs with chromic iron and magnesium carbonate on
serpentine, in Lancaster County, Pennsylvania.
Remingtonite. A hydrous cobalt carbonate, rose-colored, from
Finksburg, Md.
Spherocobaltite. A cobalt carbonate, Co O3 C, from Saxony.
Nickel Silicates. Genthite is a hydrous magnesium and nickel sili-
cate, of a pale apple-green color, yielding in one analysis 30 per cent,
of nickel oxide. From Texas, Lancaster County, Pa., and other
localities. Rottisite, from Rottis, Voigtland, is similar. Pimelite is
an impure apple-green silicate, affording in one case 15 '6 per cent, of
nickel oxide. Alipite is similar ; so also Oarnierite (and Noumeite),
from New Caledonia, and worked there for nickel.
General Remarks. — The two arsenical ores of cobalt afford the
greater part of the cobalt of commerce. The earthy oxide when
abundant is a profitable source of the metal. Erythrite (Cobalt
Bloom) occurs abundantly with other cobalt ores at its localities in
Saxony, Thuringia and Hesse Cassel. Arsenopyrite (mispickel) yields
at times 5 to 9 per cent, of cobalt. Cobalt is never employed in
the arts in a metallic state, as its alloys are brittle and unimpor-
tant. It is chiefly used for painting porcelain and pottery, and is
required for this purpose in the state of an oxide, or the silicated
oxide called smalt and azure. Zaffre is an impure oxide obtained in
the calcining of the ore with twice its weight of sand; and from it
the smalt and azure are produced. Nickel is worked in Germany,
Austria, Russia, Sweden, England, United States, and New Caledonia.
It is obtained largely from the copper nickel (niccolite) and chloan-
thite, or from an artificial product called speiss (an impure arsenide),
derived from roasting ores of cobalt containing nickel ; from siegenite
(or nickel-linnaeite), a sulphide of cobalt and nickel ; from millerite),
in part ; from the apple-green silicate ; and largely from pyrrhotite
or "magnetic iron pyrites." At the Gap Mine, near Lancaster, Pa.,
the ore is millerite and pyrrhotite ; in Missouri, the siegenite ; in
New Caledonia, chiefly the silicate.
Nickel also occurs in meteoric iron, forming an alloy with the iron,
which is characteristic of most meteorites. The proportion sometimes
exceeds 20 per cent.
As nickel does not rust or oxidize (except when heated), it is supe-
rior to steel for the manufacture of many philosophical instruments.
An alloy of copper, nickel, and zinc (one-sixth to one-third nickel),
constitutes the German silver, or argentane.
" German silver " is not a very recent discovery. In the reign of
William III., an act was passed making it felony to Uanch copper in
URANIUM. 1(59
imitation of silver, or mix it with silver for sale. " Wliite copper"
has long been used in Saxony for various small articles ; the alloy
employed is stated to consist of copper 88 '00, nickel 8 '75, sulphur
with a little antimony 0'75, silex, clay, and iron 1*75. A similar
alloy is well known in China, and is smuggled into various parts of
the East Indies, where it is called packfong. It has been sometimes
identified with the Chinese tutenague. M. Meurer analyzed the white
copper of China, and found it to consist of copper 65*24, zinc 19 '52,
nickel 13, silver 2 '5, with a trace of cobalt and iron. Dr. Fyfe ob-
tained copper 40*4, nickel 31 '6, zinc 25'4, and iron 2 '6. It has the
color of silver, and is remarkably sonorous. It is worth in China
about one-fourth its weight of silver, and is not allowed to be carried
out of the empire.
An alloy of 88 per cent, copper and 12 per cent, nickel is the mate-
rial of the United States cent, introduced in 1851. Switzerland, Bel-
gium and Jamaica also have used a nickel alloy for coins.
Nickel is mostly used at the present time for nickel-plating by
electro deposition. The value of the metal in commerce rose in the
years 1870 to 1875, from $1.25 to $3.00 per pound. The amount
annually produced is about 600 tons.
URANIUM.
Uranium ores have a specific gravity not above 7, and a
hardness below 6. The ores are either of some shade of light
green or yellow, or they are dark brown or black and dull, or
submetallic and without a metallic lustre when powdered.
They are not reduced when heated with carbonate of soda ;
and the brown or black species fuse with difficulty on the
edges or not at all.
Uraninite. — Pitchblende. Uranium Oxide.
Isometric. In octahedrons and related forms. Also mas-
sive and botryoidal. Color grayish, brownish, or velvet-
black. Lustre submetallic or dull. Streak black. Opaque.
•H.=5-5. G.=6-47.
Composition. 75 to 87 per cent, of uranium oxides with
silica, lead, iron, and some other impurities. Related to
the spinel group. B.B. infusible alone ; a gray scoria with
borax. Dissolves slowly in nitric acid, when powdered.
Obs. Occurs in veins with ores of lead and silver in
Saxony, Bohemia, and Hungary ; also in the tin mines of
Cornwall, near Eedruth. In the United States, very spar-
ingly at Middletown, Redding, and Haddam, Conn. ; in Nortb
Carolina ; on the north side of Lake Superior (Coracite).
170 DESCRIPTIONS OF MINERALS.
The oxides of uranium are used in painting upon porce-
lain, yielding a fine orange in the enameling tire, and a
black color in that in which the porcelain is baked.
Cleveit?. Hydrated oxide of uranium, iron, erbium, cerium, yttrium,
in cubic forms. From Norway.
Oummite, An amorphous uranium ore, looking like gum, of a red-
dish or brownish color. It is a hydrous uraninite, and has resulted
from its alteration. Occurs at Johanngeorgenstadt, and in North Caro-
lina.
Eliasite. Another hydrous ore, more or less resin-like in aspect, of
a reddish-brown to black color.
Hatchettolite. A hydro as columbo-tantalate of uranium, in isome-
tric octahedrons, resembling pyrochlore from North Carolina. G. =
4-76-4-84.
Blomstrandite. A hydrous titano-columbate, from Sweden.
Torbernite. — Uranite. Chalcolite. Uran-Mica.
Dimetric. In square tables, thinly foliated parallel to the
base, almost like mica ; laminae brittle.
Color emerald and grass-green ; streak a little paler.
Lustre of laminae pearly. Transparent to subtranslucent.
H. = 2-2-5. G.- 3 -4-3 -6.
Composition. A uranium-copper phosphate, consisting if
pure of Phosphorus pentoxide 15-1, uranium trioxide 61-3,
copper oxide 8 '4, water 15-3 = 100. B.B. fuses to a blackish
mass, and colors the flame green.
Diff. The micaceous structure, connected with the bright
green color and square tabular form of the crystals, are strik-
ing characters. The folia of mica are not brittle, like those
of uranite.
Obs. Occurs with uranium, silver and tin ores. It is
found at St. Symphorien, in splendid crystallizations, near
Redruth and elsewhere in Cornwall ; in the Saxon and
Bohemian mines ; in North Carolina.
Autunite is similar to torbernite ; but has a bright citron-yellow
color, and is a uranium-calcium phosphate. From the same mining
^regions, also from near Autun in France, and sparingly, from Portland,
Middletown, and Redding, Conn.; Acworth, N. H. ; Chesterfield, Mass.;
and in North Carolina.
Uranospinite is an autunite containing arsenic instead of phos-
phorus ; and Zeunerite is a torbernite containing arsenic instead of
phosphorus.
Samarskite (formerly named uranotantalite and yttroilmenite) is a
compound of oxyd of uranium with columbic and tungstic acids, from
Miask in the Ural. It is of a dark brown color and submetallic lustre.
H=5'5. G.=5'4-5'7. Abundant in North Carolina.
IRON. 171
Johannite or Uranmtriol is a sulphate of uranium. It has a fine
emerald-green color, and a bitter taste. From Bohemia.
Trdgerite and Walpurg&e are uranium arsf nates. Voglite and
Liebigite are uranium carbonates. Johnnnite is a uranium vitriol ;
Uranochalcitc , Medijdile, Zippeite, Voglianite, Uraconite, are other
uranium sulphates.
Uranocircite is a hydrous barium-uranium phosphate.
IRON.
Iron occurs native, and alloyed with nickel in meteoric iron.
Its most abundant ores are the oxides and sulphides. It is
also found combined with arsenic, forming arsenides and
sulpharsenides ; with oxygen and other metals, as chro-
mium, aluminum, magnesium ; and in the condition of sul-
phate, phosphate, arsenate, columbate, silicate and carbon-
ate, of which the last is an abundant and valuable ore.
Its ores are widely disseminated. The oxides and silicates
are the ordinary coloring ingredients of soils, clays, earth and
many rocks, tinging them red, yellow, dull green, brown,
and black.
The ores have a specific gravity below 8, and the ordinary
workable ores seldom exceed 5. Many of them are infusible
before the blowpipe, and nearly all minerals containing iron
become attractable by the magnet after heating, when not
so before. By their difficult fusibility, the species with a
metallic lustre are distinguished from ores of silver and cop-
per, and also more decidedly from these and other ores by
blowpipe reaction.
Native Iron.
Isometric. Usually massive with octahedral cleavage.
Color and streak iron-gray. Fracture hackly. Malleable
and ductile. H. =4 -5. G. =7 -3-7 -8. Acts strongly on the
magnet.
Obs. Native iron occurs in grains disseminated through
some doleryte, basalt, and other related igneous rocks ; and
in Greenland, in very large masses in such igneous rocks,
the largest weighing over a ton. It is suggested by J.
Lawrence Smith, that the iron was reduced "by means of
carbohydrogen vapors, taken into the rock from carbonaceous
rocks passed through on the way to the surface.
172
DESCRIPTIONS OP MINERALS.
It is a constituent of nearly all meteorites, and the chief
ingredient in a large part of them ; and in this state it is
with a rare exception alloyed with nickel, and with traces
of cobalt and copper. The Texas meteorite, of Yale College,
weighs 1,635 pounds ; the Pallas meteorite, now at Vienna,
originally 1,600 ; but one in Mexico, the San Gregorio
meteorite, is stated to weigh five tons ; and one in the dis-
trict of Chaco-Gualamba, S. A., nearly fifteen tons. Meteoric
iron often has a very broad crystalline structure, long lines
and triangular figures being developed by putting nitric acid
on a polished surface. The coarseness of this structure dif-
fers in different meteorites, and serves to distinguish speci-
mens not identical in origin. Nodules of troilite (FeS),
and schreibersite (iron phosphide) are common in iron me-
teorites. Meteoric iron may be worked like ordinary malle-
able iron. The nickel diminishes the tendency to rust. But
some kinds contain iron chloride, or are open in texture, and
rust badly.
Pyrite. — Iron Pyrites. Iron Bisulphide.
Isometric. Usually in cubes, the strise of one face at right
angles with those of either adjoining face, as in fig. 1. Also
IRON. 173
figs. 2 to 7 ; also figs. 8 to 15 on page 6. Fig. 6, a pentag-
onal dodecahedron, is a common form. Occurs also in imi-
tative shapes, and massive.
Color brass-yellow ; streak brownish black. Lustre of
crystals often splendent metallic. Brittle. H. = 6-6-5, be-
ing hard enough to strike fire with steel. G. =4: -8-5-1.
Composition. Fe S2 — Sulphur 53-3, iron 46-7 = 100.
B.B. on charcoal gives off sulphur, and ultimately affords
a globule attractable by the magnet.
Pyrite often contains a minute quantity of gold, and
is then called auriferous pyrite. See under Gold. Nickel,
cobalt and copper occur in some pyrite.
Diff. Distinguished from copper pyrites in being too hard
to be cut by a knife, and also in its paler color. The ores
of silver, at all resembling pyrite, instead of having its pale
bronze-yellow color, are steel-gray or nearly black ; and be-
sides, they are easily scratched with a knife and quite fusible.
Gold is sectile and malleable.
Obs. Pyrite is one of the most common ores on the
globe. It occurs in rocks of all ages. Cornwall, Elba,
Piedmont, Sweden, Brazil, and Peru, have afforded magnifi-
cent crystals. Alston Moor, Derbyshire, Kongsberg in Nor-
way, are well-known localities. It has also been observed in
the Vesuvian lavas, and in many other igneous rocks.
In the United States, the localities are numerous. Fine
crystals have been met with at Eossie, N. Y. ; at many
other places in that State ; also in each of the New England
States and in Canada ; in New Jersey, Pennsylvania, Vir-
ginia, North Carolina, Georgia, in Colorado, Wyoming and
the States west. It occurs in all gold regions, and is one
source of gold.
This species is of the highest importance in the arts,
although not affording good iron on account of the diffi-
culty of separating entirely the sulphur. It affords the
greater part of the sulphate pf iron (green vitriol or copperas)
and sulphuric acid (oil of vitriol) of commerce, and also
a considerable portion of the sulphur and alum. To make
the sulphate the pyrites is sometimes heated in clay retorts,
by which about 17 "per cent, of sulphur is distilled over and
collected. The ore is then thrown out into heaps, exposed
to the atmosphere, when a change ensues by which the re-
maining sulphur and iron become through oxidation sul-
phate of iron. The material is lixiviated, and partially eva-
174 DESCRIPTIONS OF MINERALS.
porated, preparatory to its being run off into vats or troughs
to crystallize. In other instances, the ore is coarsely broken
up and piled in heaps and moistened. Fuel is sometimes
used to commence the process, which afterwards the heat
generated continues. Decomposition takes place as before,
with the same result. Cabinet specimens of pyrite, espe-
cially granular or amorphous masses, often undergo a spon-
taneous change to the sulphate, particularly when the atmo-
sphere is moist.
Pyrite, owing to its tendency to oxidation, and its very
general distribution in rocks of all kinds and ages, is one of
the chief sources of the disintegration and destruction of
rocks. No granite, sandstone, slate, or limestone, contain-
ing it, is fit for architectural purposes or for any outdoor
uses. The same destructive effects come from pyrrhotite and
marcasite, which also are widely diffused.
The name pyrites is from the Greek pur, fire, because, as
Pliny states, "there was much fire in it," alluding to its
striking fire with steel. Thi.3 ore is the mundic of miners.
Marcasite or White iron pyrites. This ore has the same composition as
pyrites, but differs in crystallizing in trimetic forms. /A/=106° 36 .
The color is a little paler than that of pyrite, and it is more liable to
decomposition ; hardness the same ; specific gravity 4'6-4'85. Radi-
ated pyrites, Hepatic pyrites, Cockscomb pyrites (alluding to its crested
shapes;, and Spear pyrites, are names of some of its varieties. It oc-
curs in crystals at Warwick and Phillipstown, N. Y. Massive varie-
ties are met with at Cummington, Mass.; Monroe, Trumbull, and
East Haddam, Conn. ; and at Haverhill, N. H.
Pyrrhotite. — Magnetic Pyrites. Iron Sulphide.
Hexagonal. Occurs occasionally in hexagonal prisms,
which are often tabular ; generally missive.
Color between bronze-yellow and copper-red ; streak dark
grayish-black. Brittle. H. =3-5 -4-5. G.=4«4-4;65.
Slightly attracted by the magnet. Liable to speedy tarnish.
Composition. Fe7 S8=: Sulphur 39-5, iron 60-5. It is
often a valuable ore of nickel, containing sometimes 3 to
5 per cent, of this metal. B.B. on charcoal in the outer
flame it is converted into red oxide of iron. In the inner
flame it fuses and glows, and affords a black globule which
is magnetic, and has a yellowish color on a surface of frac-
ture.
Diff. Its inferior hardness and shade of color, and its
IRON. 175
magnetic quality distinguish it from pyrite ; and its pale-
ness of color from chalcopyrite or copper pyrites.
Obs. Crystallized specimens have been found at Kongs-
berg in Norway, and at Andreasberg in the Hartz. The
massive variety is found in Cornwall, Saxony, Siberia, and
the Hartz ; also at Vesuvius and in meteoric stones.
In the United States, it is met with at Trumbull and
Monroe, New Fairfield, and Litchfield, Conn. ; at Straff ord
and Shrewsbury, Vt. ; at Corinth, New Hampshire; in
many parts of Massachusetts and New York ; at Lancaster,
Pa., where it is worked for nickel. It is used for making
green vitriol and sulphuric acid, like pyrite.
Troilite is a similar mineral of the formula Fe S, occur-
ring in meteorites. Schreibersite is a phosphide of iron and
nickel, occurring in meteorites.
Arsenopyrite. — Mispickel. Arsenical Iron Pyrites.
Trimetric. In rhombic prisms, with cleavage parallel to
the faces /; /A/=lll° 40' to 112°.
Crystals sometimes elongated horizon-
tally, producing a rhombic prism of
100° nearly, with / and / the end
planes. Occurs also massive.
Color silver-white ; streak dark
grayish-black. Lustre shining. Brit-
tle. H.=5-5-G. G.=6-3.
Composition. Fe AsS — Arsenic 46 -0,
sulphur 19-6, iron 34-4=100. A co-
baltic variety contains 4 to 9 per cent, of cobalt in place
of part of the iron ; Danaite of New Hampshire, consists
of Arsenic 41-4, sulphur 17-8, iron 32-9, cobalt 6-5. B.B.
affords arsenical fumes, and a globule of iron sulphide
which is attracted by the magnet. In the closed tube a
sublimate of arsenic sulphide. Gives fire with a steel and
emits a garlic odor.
Diff. Eesembles arsenical cobalt, but is much harder,
it giving fire with steel; it differs also in yielding a mag-
netic globule before the blowpipe, and in not affording the
reaction of cobalt with the fluxes.
Obs. Arsenopyrite is found mostly in crystalline rocks, and
is commonly associated with ores of silver, lead, iron, or cop-
per. It is abundant at Freiberg, Munzig, and elsewhere in
Europe, and also in Cornwall, England.
176 DESCRIPTIONS OF MINERALS.
It occurs in crystals in New Hampshire, at Franconia,
Jackson, and Haverhill ; in Maine, at Blue Hill Bay, Corinth,
Newfield, and Thomaston ; in Vermont, at Waterbury ; in
Massachusetts, massive at Worcester and Sterling ; in Con-
necticut, at Chatham, Derby, and Monroe ; in New Jersey,
at Franklin ; in New York, in Lewis, Essex County, and
near Edenville and elsewhere in Orange County ; in Kent,
Putnam County.
Leucopyrite. This is the name of arsenical iron Fe2 As3. It re-
sembles the preceding in color and in its crystals. I f\ 7=122° 20'.
It has less hardness and higher specific gravity. H. =5-5*5. G. =7'2
-7 '4. Contains Iron 32 '2, arsenic GO '9, with some sulphur. From
Styria, Silesia, and Carinthia.
Lollingite is another iron arsenide, Fe As.2=Arsenic 72'8, iron 27'2 ;
specific gravity 6 '8-8 '71. Berthierite is an iron sulphantimonite.
Hematite. — Specular Iron Ore. Iron Sesquioxide.
Khombohedral. In complex modifications of a rhombohe-
3.
dron of 86° 10' (fig. 1); crystals occasionally thin tabular.
Cleavage usually indistinct. Often massive granular ; some-
times lamellar or micaceous. Also pulverulent and earthy.
Color dark steel-gray or iron-black, and often when crys-
tallized having a highly splendent lustre ; streak-powder
cherry-red or reddish -brown. The metallic varieties pass
into an earthy ore of a red color, having none of the external
characters of the crystals, but perfectly corresponding to them
when they are pulverized, the powder they yield being of a
deep red color, and earthy or without lustre. Gr. =4-5-5 -3.
Hardness of crystals 5 -5-6 -5. Sometimes slightly attracted
by the magnet.
VARIETIES.
Specular iron. Having a perfectly metallic lustre.
Micaceous iron. Structure foliated.
Red hematite. Submetallic, or unmetallic, and of a brown-
ish-red color.
Red ochre. Soft and earthy, and often containing clay.
IRON. 177
Red chalk. More firm and compact than red ochre, and
of a fine texture.
Jasper y clay iron. A ha1*d impure siliceous clayey ore,
and having a brownish-red jaspery look and compactness.
Clay iron stone. The same as the last, the oolor and ap-
pearance less like jasper. But this is one variety only of
what is called "clay iron stone," a name covering also a re-
lated variety of siderite and limonite.
Lenticular argillaceous ore. A red ore, consisting of
small flattened grains.
Martite is hematite in octahedrons, derived, it is supposed,
from the oxidation of magnetite.
Composition. Fe03 = Oxygen 30, iron 70 = 100. B.B.
alone infusible. Heated in the inner flame it becomes
strongly magnetic.
Diff. The red powder of this mineral, and the magnetism
which is so easily induced in it by a reduction flame dis-
tinguish hematite from all other ores. The word hematite,
from the Greek haima, blood, alludes to the color of the
powder.
Obs. This ore occurs in crystalline and stratified rocks of
all ages. The more extensive beds of pure ore abound in
Archaean rocks ; while the argillaceous varieties occur in
stratified rocks, being often abundant in coal regions and
among other strata. Crystallized specimens are found also
in some lavas, as a volcanic product.
Splendid crystallizations of this ore come from Elba, whose
beds were known to the Romans ; also from St. Gothard ;
Arendal, Norway ; Longbanshyttan, Sweden ; Lorraine and
Dauphiny. Etna and Vesuvius afford handsome specimens.
In the "United States, this is an abundant ore. The two
Iron Mountains of Missouri, situated 90 miles south of St.
Louis, consist mainly of this ore, piled " in masses of all
sizes from a pigeon's egg to a middle-are church." One of
them is 300 feet high, and the other, the "Pilot Knob," is
700 feet. The massive and micaceous varieties occur there
together with red ochreous ore. Large beds occur in Essex,
St. Lawrence and Jefferson counties, N. Y., and at Mar-
quette, in Michigan; the micaceous variety, at Hawley, Mass.,
Piermont, N. H., and in Stafford County, Va.; lenticular
argillaceous ore abundantly in Oneida, Herkimer, Madison
and Wayne counties, N. Y., constituting one or two beds of
the Clinton group (tipper Silurian), in a compact sandstone ;
178 DESCRIPTIONS OF MINERALS.
and the same is found in Pennsylvania and south to Alabama,
and also in Wisconsin ; it contains 50 per cent, of oxide of
iron, with about 25 of carbonate of lime and more or less
magnesia and clay. The coal region of Pennsylvania affords
abundantly the clay iron ores, but they are mostly either the
argillaceous carbonate or limonite.
Valuable as an iron ore, though less easily worked when
pure and metallic than the magnetic and hydrous ores. Pul-
verized red hematite is used for polishing metal. Eed chalk
is a well-known material for red pencils.
Menaccanite. — Ilmenite. Titanic Iron. Washingtonite.
Ehombohedral. 72A72-S50 31'. Often in thin plates or
seams in quartz ; also in grains. Crystals sometimes very
large and tabular.
Color iron-black ; streak submetallic. Lustre metallic or
submetallic. H. =5-6. G. =4'5-5. Acts slightly on the
magnetic needle.
Composition. Like that of hematite, except that part of
the iron is replaced by titanium ; the amount replaced is
very variable. Infusible alone before the blowpipe.
Diff. Near specular iron, bat its powder is not red.
Obs. Crystals, an inch or so in diameter, occur in War-
wick, Amity and Monroe, Orange County, N. Y. ; also near
Edenville and Greenwood Furnace ; also at South Royalston
and Goshen, Mass. ; at Washington, South Britain, and
Litchfield, Conn. ; at Westerly, Rhode Island.
* It is of no value in the arts and is a deleterious constitu-
ent of many iron ores.
Magnetite. — Magnetic Iron Ore.
Isometric. Often in octahedrons (fig. 1), and dodecahe-
drons (fig. 2 ). Cleavage octahe- g
dral ; sometimes distinct. Also
granularly massive. Occasionally
in dendritic forms between the
folia of mica.
Col or iron-black. Streak black.
Brittle. II.— 5*5-6-5. G.=--5'0
-5*1. Strongly attracted by the
magnet, and sometimes having polarity.
Composition. Fe£e04=:FeO-f Ee03= Oxygen 27'6, iron
IRON. 179
72-4=100. Infusible before the blowpipe. Yields a yellow
glass when fused with borax in the outer flame.
Diff. The black streak and strong magnetism distinguish
this species from the following.
Obs. Magnetic iron ore occurs in extensive beds, and also
in disseminated crystals. It is met with in granite, gneiss,
mica schist, clay slate, syenyte, hornblende and chlorite
schist ; and also sometimes in limestone.
The beds at Arendal, and nearly all the Swedish iron ore,
consist of massive magnetic iron. At Dannemora and the
Taberg in Southern Sweden, and also in Lapland at Kurun-
avara and Gelivara, there are mountains composed of it.
In the United States it constitutes extensive beds, in Ar-
chaean rocks, in Warren, Essex, Clinton, Orange, Putnam,
Saratoga and Herkimer counties, New York; and in Sussex
and Warren counties, in New Jersey. Smaller deposits occur
in the several New England States and Canada. Also found
at Magnet Cove, in Arkansas ; in California, in Sierra
County, and elsewhere. It exists with hematite in the Iron
Mountains of Missouri.
Masses of this ore, in a state of magnetic polarity, consti-
tute what are called lodestones or native magnets. They are
met with in many beds of the ore. Siberia and the Hartz
have afforded fine specimens ; also the Island of Elba. They
also occur at Marshall's Island, Maine; also near Providence,
Rhode Island, and at Magnet Cove, in Arkansas. The
lodestone is called magnes by Pliny, from the name of the
country, Magnesia (a province of ancient Lydia), where it
was found ; and it hence gave the terms magnet and mag-
netism to science.
Franklinite.
Isometric. In octahedral and dodecahedral crystals. Also
coarse granular massive. Color iron-black ; streak dark
reddish-brown. Brittle. H.^5'5-6'5. G. =4-85-51. Usually
is attracted by the magnet.
Composition. General formula like that of magnetite,
RE 04, but having zinc and manganese replacing part of the
iron, as indicated in the formula (Fe, Zn, Mn) (fee,Mn)04.
A common variety corresponds to Fes 03 G7'6, Fe 0 5 '8, Zn O
6-9, MnO 9-7=100.
B.B. with soda on charcoal a zinc coating is obtained ; a
180 DESCRIPTIONS OP MINERALS.
soda bead in the outer flame is colored green by the manga-
nese.
Diff. Resembles magnetic iron, but the exterior color is a
more decided black. The streak is reddish brown, and the
blowpipe reactions are distinctive.
Obs. This is an abundant ore at Sterling and Hamburg,
in New Jersey, near the Franklin Furnace ; at the former
place the crystals are sometimes four inches in diameter ;
also amorphous at Altenberg, near Aix-la-Chapelle.
Chromite. — Chromic Iron.
Isometric. In octahedral crystals, without distinct cleav-
age. Usually massive, and breaking with a rough unpolished
surface.
Color iron-black and brownish black ; streak dark brown.
Lustre submetallic ; often faint. H. =5-5. G. =4*3-4-6.
In small fragments attractable by the magnet.
Composition. General formula RR 04, as for magnetite ;
but part of the iron is replaced by chromium. Analysis
gives Iron protoxide 32, chromium sesquioxide 68 = 100;
aluminum and magnesium also are commonly present in
variable amounts, replacing the other constituents. B. B.
infusible alone ; with borax a beautiful green bead.
This ore usually possesses a less metallic lustre than the
other black iron ores.
Obs. Occurs usually in serpentine rocks, in imbedded
masses or veins. Some of the foreign localities are the
Gulsen Mountains in Styria ; the Shetland Islands ; the de-
partment of Var in France ; Silesia, Bohemia, etc.
In the United States it is abundant : in Maryland in the
Bare Hills, near Baltimore, and also in Montgomery County,
at Cooptown, in Harford County ; and in the north part of
Cecil County ; occurs also in Townsend and Westfield, Ver-
mont, and at Chester and Blandford, Mass. It is also found
in Pennsylvania, at Wood's Mine, near Texas, Lancaster
County, in West Branford, Chester County ; at Bolton and
Ham, Canada East ; in California near New Idria ; also in
Sonoma County ; Tuolumne County, near Crimea House,
and elsewhere ; at Seattle in Wyoming.
The compounds of chromium, which are extensively used
as pigments, are obtained chiefly from this ore. Meteorites
have afforded a chromium-sulphide, named Daubreelite.
IRON. 181
Limonite. — Brown Hematite.
Usually massive, and often with a smooth botryoidal or
stalactitic surface, having a compact fibrous structure with-
in. Also earthy.
Color dark brown and black to ochre-yellow ; streak yellow-
ish brown to dull yellow. Lustre sometimes submetallic ;
often dull and earthy ; on a surface of fracture frequently
silky. H.=5-5-5. G.=3'6-4.
The following are the principal varieties :
Brown hematite. The botryoidal, stalactitic and asso-
ciated compact ore.
Brown ochre, Yelloiv ochre. Earthy ochreous varieties, of
a brown or yellow color.
Brown and Yellow day iron stone. Impure ore, bard and
compact, of a brown or yellow color.
Bog iron ore. A loose earthy ore of a brownish-black
color, occurring in low grounds.
Composition. Ee 09 H 6 ( = 2 Fe 03 + 3 H2 0) — Iron sesqui-
oxide 85-6, water 14-4-100; or it is a hydrous iron ses-
quioxide, containing, when pure, about two-thirds its weight
of pure iron. B.B. blackens and becomes magnetic; with
borax in the outer flame a yellow glass.
Diff. This is a much softer ore than either of the two
preceding, and is peculiar in its frequent stalactitic forms,
and in its affording water when heated in a glass tube.
Obs. Occurs connected with rocks of all ages, but ap-
pears, as shown by the stalactitic and other forms, to have
resulted in all cases from the decomposition of other iron
ores.
An abundant ore in the United States. Extensive beds
exist in Salisbury and Kent, Conn. , also in the neighboring
towns of Beekman, Fishkill, Dover, Amenia, X. Y.; also in
a similar situation north, in Richmond and West Stock-
bridge, Mass. ; also in Bennington, Monkton, Pittsford,
Putney, and Ripton, Vermont. *" Large beds are found in
Pennsylvania, the Carolinas, near the Missouri Iron Moun-
tains, and also in Tennessee, Iowa and Wisconsin.
This is one of the most valuable ores of iron. The limo-
nite of Western New England, and that along the same
range geologically in Dutchess County, New York, Eastern
Pennsylvania, and beyond, is remarkably free from phos-
phorus, and hence is highly valued for its iron. Bog orea
182 DESCRIPTIONS OF MINERALS.
usually contain much phosphorus, from organic sources,
and hence the iron afforded is best fitted for castings. Li-
monite is also pulverized and used for polishing metallic
buttons and other articles. As yellow ochre, it is a common
material for paint.
Gothite (Pyrrlwsidcrite, Lepidokrokite) is another iron hydrate, often
in prismatic crystals, as well as fibrous and massive, of the formula Fe
O4 H2( = Ee O3 + H, O), and G. = 4 -0-4 -4:
Turgite has the formula EeO7 Ha=2EeO3 + H20. Xantho#iderit&
and limnite are other related hydrates.
Melanterite. — Copperas. Iron Vitriol. Green Vitriol.
Monoclinic. In acute oblique rhombic prisms. / A /=
82° 21'; 0 A 7= 80° 37'. Cleavage parallel to 0 perfect.
Generally pulverulent or massive.
Color greenish to white. Lustre vitreous. Subtranspa-
rent to translucent. Taste astringent, sweetish, and metal-
lic. Brittle. H.=2. G.=l-83.
Composition. Fe 04S 4- 7aq= Sulphur trioxide 28-8, iron
protoxide 25-9, water 45-3 = 100. B.B. becomes magnetic.
Yields glass with borax. On exposure, becomes covered
with a yellowish powder, which results from oxidation.
Obs. This species is the result of the decomposition of
pyrite and pyrrhotite, which readily afford it if moistened
while exposed to the atmosphere, and it is obtained from
these sulphides for the arts (p. 173). An old mine near
Goslar, in the Hartz, is a noted locality.
Copperas is much used by dyers and tanners, on account
of its giving a black color with tannic acid, an ingredient in
nutgalls and many kinds of bark. It for the same reason
forms the basis of ordinary ink, which is essentially an in-
fusion of nutgalls and copperas. It is also employed in the
manufacture of Prussian blue. With potassium ferrocya-
nide, any soluble salt of iron sesquioxicle, even in minute
quantity, gives a fine blue color to the solution (due to the
formation of Prussian blue), and this is a delicate test of the
presence of iron.
CoquimUte, Copiaptte, Voltaitt, Raimondite, Botryogeri, Fibroferrite,
Ihleite, are names of other hydrous iron sulphates ; and Halotrichite
is an iron-alum.
Jarosite is a hydrous iron-potash sulphate.
Pisanite is an iron-copper vitriol.
Lagonite. A hydrous iron borate, from the Tuscan lagoons.
IRON.
183
Wolframite. — Wolfram. Iron-Manganese Tungstate.
Monoclinic. Sometimes pseudomorphous in octahedrons
formed by the alteration of tungstate of lime. Also massive.
Color dark grayish-blaok ; streak dark reddish-brown.
Lustre submetallic, shining, or dull. H. =5-5*5. G. =
7-1-7-5.
Composition. (Fe,Mn)04W. A typical variety affords
tungsten trioxide 76*47, iron protoxide 9*49, manganese
protoxide 14*04=100. A manganese wolframite has been
named Hiibnerite. B.B. fuses easily to a magnetic globule ;
with aqua regia dissolved with the separation of yellow
tungsten trioxide.
Found often with tin ores. Occurs in Cornwall, and at
Zinnwald and elsewhere in Europe. In the United States it
is found at Monroe and Trumbull, Conn. ; on Camdage
Farm, near Blue Hill Bay, Me. ; near Mine la Motte, Mis-
souri ; in the gold regions of North Carolina ; in Mammoth
Mining district, Nevada Hiibnerite.
Columbite.
Trimetric. In rectangular prisms, more or less modified.
Also massive. Cleavage parallel to
the lateral faces of the prism, some-
what distinct.
Color iron-black, brownish-black ;
often with a characteristic iridescence
on a surface of fracture ; streak dark
brown, slightly reddish. Lustre sub-
metallic, shining. Opaque. Brittle.
H.=r5-G. G.=o-4-6-5.
Composition. Iron columbate, of
the formula F 06 Cb.2 = Columbium
pentoxide 79'G, iron protoxide 16'4,
manganese protoxide 4'4, tin oxide 0'5, lead and copper
oxides 0*1 = 100. Tantalum often replaces part of the
columbium, and in this case the mineral is of higher speci-
fic gravity. B.B. alone infusible. It imparts to the borax
bead the yellow color of iron.
Diff. Its dark color, submetallic lustre, and a slight iri-
descence, together with its breaking readily into angular
fragments, will generally distinguish this species from the
ores it resembles.
184 DESCRIPTIONS OP MINERALS.
Ols. Occurs in granite at Bodenmais in Bavaria, and
also in Bohemia. In the United States, it is found in gra-
nitic veins, at Middletown and Haddam, Conn. ; at Ches-
terfield and Beverly, Mass. ; at Ac worth, N. H. ; Green-
field, N. Y. A crystal was found at Middletown, which
originally weighed 14 pounds avoirdupois ; and a part of it,
6 inches in length and breadth, weighing 6 Ibs. 12 oz., is now
in the collections of the Wesleyan University of that place.
Also at Standisb, Maine ; and in granite veins in North
Carolina.
This mineral was first made known from American speci-
mens, by Mr. Hatchett, an English chemist, and the new
metal it was found to contain was named by him columbium.
Tantalite. Fe(Mn) O6 Ta2. This tantalate of iron is allied to colum-
bite. H. 6-6 '5. G. 7-8. It is distinguished by its higher specific
gravity. It sometimes contains tin and tungsten. From Finland,
Sweden, near Limoges in France, and from North Carolina and
Alabama.
Note. — The metal named Columbium by Hatchett, is the same that
has since been called Niobium, without any good reason for the change
of name.
Triphylite. An iron manganese-lithium phosphate. See p. 190.
Vivianite. — Hydrous Iron Phosphate.
Monoclinic. In modified oblique prisms, with cleavage
in one direction highly perfect. Also radiated, reniform,
and globular, or as coatings.
Color deep blue to green. Crystals usually green at right
angles with the vertical axis, and blue parallel to it. Streak
bluish. Lustre pearly to vitreous. Transparent to translu-
cent ; opaque on exposure. Thin laminae flexible. H. =
1-5-2. G.=2'66.
Composition. Pe3 08 P2 + 8aq = Phosphorus pentoxide,
28-3, iron protoxide 43-0, water 28-7 = 100. B.B. fuses
easily to a magnetic globule, coloring the flame greenish
blue. Affords water in a glass tube, and dissolves in hydro-
chloric acid.
Diff. The deep blue color and the little hardness are
decisive characteristics. The blowpipe affords confirma-
tory tests.
Obs. Found with iron, copper and tin ores, and some-
times in clay, or with bog iron ore. St. Agnes in Cornwall,
Bodenmais, and the gold mines of Vorospatak in Transylva-
nia, afford fine crystallizations. In the United States, good
IRON. 185
crystals have been found at Imlaystown, N. J. At Allentown,
Monmonth County, and Mullica Hill, Gloucester County, N.
J., are other localities. It often fills the interior of certain
fossils. Occurs also at Harlem, N. Y., in Somerset and
Worcester counties, Md., and with bog ore in Stafford
County, Va. Abundant at Vandreuil in Canada, where it
is associated with limonitc.
The blue iron earth is an earthy variety, containing about 30 per
cent, of phosphoric acid.
Ludlamite. A clear green hydrous phosphate of iron in monoclinic
crystals ; from Cornwall.
Dufrenite. A hydrous phosphate of iron sesquioxide. It has a dull
green color, and is often found in radiated forms.
Cacoxenite. Occurs in radiated silky tufts of a yellow or yellow-
ish-brown color. H. = 3-4. G.=3P38. • It is a phosphate of iron
sesquioxide, and often contains alumina. It differs from wavellite,
which it resembles, in its more yellow color and iron reactions. It
also resembles carpholite, but has a deeper color, and does not give
the manganese reactions. It occurs on brown iron ore in Bohemia.
Clialcosideritc, and Andrewsite are other iron phosphates.
Strengite. A hydrous iron phosphate related in formula to scoro-
dite. From near Giessen.
Ar senates of Iron.
Pharmacosiderite, or Cube ore. Occurs in cubes of dark green to
brown and red colors. Lustre adamantine, not very distinct. Streak
greenish or brownisTi. H.=2'5. G. =3. It is a hydrous arsenate of
iron sesquioxide, containing 43 per cent, of arsenic pentoxide. From
the Cornwall mines ; also from France and Saxony.
Scorodite. Crystallizes in rhombic prisms, with an angle of 120° 10'
between its secondary prismatic planes. Color pale leek -green or liver
brown. Streak uncolored. Lustre vitreous to subadamantine. Sub-
transparent to nearly opaque. H. = 3*5-4. G. =3'l-3'3. A hydrous
arsenate of iron sesquioxide, containing 50 per cent, of arsenic pen-
toxide. From Saxony, Carinthia, Cornwall, and Brazil ; and minute
crystals near Edenville, N. Y., with arsenical pyrites. The name of
this species is from the Greek skorodon, garlic, alluding to the odor
before the blowpipe. Iron sinter is an amorphous form of the same
mineral.
Arseniosidcrite is another iron arsenate.
Siderite.— Spathic Iron. Iron Carbonate.
Ehombohedral. In rhombohedrons with easy cleavage
parallel to a rhombohedron of 107°. Faces often
curved. Usually massive, with a foliated struc-
ture, somewhat curving. Sometimes in globular
concretions or implanted globules.
Color light grayish to brown; often dark
brownish -red. It becomes nearly black on ex-
186 DESCRIPTIONS OF MINERALS.
posure. Streak tincolored. Lustre pearly to vitreous. Trans*
lucent to nearly opaque. H. =3-4-5. G. =3-7-3-9.
Composition. Fe 03C = Carbon dioxide 3 7 -9, iron protox-
ide 62-1 = 100. Often contains some manganese oxide 01
magnesia, and lime replacing part of the iron protoxide.
Before the blowpipe it blackens and becomes magnetic ; but
alone it is infusible. Dissolves in heated hydrochloric acid
With effervescence.
The ordinary crystallized 01 foliated variety is called
spathic or sparry iron, because the mineral has the aspect
of a spar. The globular concretions found in some amygda-
loidal rocks have been called splierosiderite because of its
spheroidal forms. An argillaceous variety occurring in nod-
ular forms is often called clay iron stone, and is abundant
in coal measures.
Diff. This mineral cleaves like calcite and dolomite, but
it has a much higher specific gravity. It readily becomes
magnetic before the blowpipe. Heated in a closed glass
tube it gives off carbon dioxide, and becomes magnetic. This
test distinguishes it from other iron ores.
Obs. Spathic iron occurs in rocks of various ages, and
often accompanies metallic ores. The largest deposits are
in gneiss and mica schist, and clay slate. It is also abundant
in the coal formation principally in the form of clay iron
stone. In Styria and Carinthia, it is very abundant in gneiss,
and in the Hartz it occurs in graywacke. Cornwall, Alston-
moor, and Devonshire are English localities.
A vein of considerable extent occurs at Roxbury, near
New Milford, Conn., in quartz, traversing gneiss; "at Ply-
mouth, Vt., and Sterling, Mass., it is also abundant. It oc-
curs also at Monroe, Conn. ; in New York State, in Antwerp,
Jefferson County, and in Hermon, St. Lawrence County.
The argillaceous carbonate in nodules and beds, is very
abundant in the coal regions of Pennsylvania and the West.
This ore is employed extensively for the manufacture of
iron and steeL
Mesitite is an iron-and-magnesium carbonate. Ankerite contains in
addition a large percentage of calcium. Like siderite in crystalliza-
tion and cleavage.
General Remarks. — The metal iron has been known from the most
remote historical period, but was little used until the last centuries be-
fore the Christian era. Bronze, an alloy of copper and tin, was the
almost universal substitute, for cutting instruments as well as weapons
IRON. 187
of war, among the ancient Egyptians and earlier Greeks ; and even
among the Romans (as proved by the relics from Pompeii), and also
throughout Europe, it continued long to be extensively employed for
these purposes.
The Chalybes, bordering on the Black Sea, were workers in iron and
steel at au early period ; and near the year 500 B.C., this metal was
introduced from that region into Greece, so as to become common for
weapons of war. From this source we have the expression chalybeate
applied to certain substances or waters containing iron.
The iron mines of Spain have also been known from a remote epoch,
and it is supposed that they have been worked " at least ever since
the times of the later Jewish kings ; first by the Tyrians, next by the
Carthaginians, then by the Romans, and lastly by the natives of the
country." These mines are mostly contained in the present provinces
of New Castile and Aragon. Elba was another region of ancient works,
"inexhaustible in its iron," as Pliny states, who enters somewhat fully
into the modes of manufacture. The mines are said to have yielded
iron since the time of Alexander of Macedon. The ore beds of Styria
in Lower Austria, were also a source of iron to the Romans.
The ores from which the iron of commerce is obtained, are the
spathic iron or carbonate, magnetic iron, hematite or specular iron,
limonite or "brown hematite," and bog iron ore. In England, the prin-
cipal ore used is an argillaceous carbonate of iron, called often clay
iron stone, found in nodules and layers in the coal measures. It con-
sists of carbonate of iron, with some clay, and externally has an earthy,
stony look, with little indication of the iron it contains except in its
weight. It yields from 20 to 35 per cent, of cast iron. The coal basin
of South Wales, and the counties of Stafford, Salop, York, and Derby,
yield by far the greater part of the English iron. Brown hematite is
also extensively worked. In Sweden and Norway, at the famous
works of Dannemora and Arcndal, the ore is the magnetic iron ore,
and is nearly free from impurities as it is quarried out. It yields 50 to
60 per cent, of iron. The same ore is worked in Russia, where it
abounds in the TJrals. The Elba ore is the specular iron. In Germany,
Styria, and Carinthia, extensive beds of the spathic iron are worked.
The bog ore is largely reduced in Prussia.
In the United States, all these different ores are worked. The local-
ities are already mentioned. The magnetic ore is reduced in New
England, New York, Northern New Jersey, and sparingly in Pennsyl-
vania, and other States. Limonite, or brown hematite, is largely
worked along Western New England and Eastern New York, in Penn-
sylvania, and many States South and West. The earthy argillaceous
carbonate like that of England, and the hydrate, are found with the
coal deposits, and are a source of much iron.
The amount of iron manufactured in the world in the year 1873 was
14,835,488 tons, of which Great Britain produced 6,566,000 tons,
United States, 2,561,000 tons, Germany 1,665,000 tons, France 1,331,000
tons, Belgium 653,000 tons, Austria with Hungary 425,000 tons, Russia
354,000 tons, Sweden 322,000 tons, Luxembourg 300,000 tons.
188 DESCRIPTIONS OF MINERALS.
MANGANESE.
The common ores of manganese are the oxides, the car-
bonate, and the silicates. There are also sulphides, an
arsenide, and phosphate. They haye a specific gravity be-
low 5 -2.
Manganese Sulphides and Arsenide,
Aldbandite or Mangariblende. A manganese sulphide Mn S, of an
iron-black color, green streak, submetallic lustre. H. =8*5-4 G.—
3*9-4'0. Crystals, cubes and regular octahedrons. From the gold
mines of Nagyag, in Transylvania.
Hauerite. A sulphide, Mn S1', containing twice the proportion of
sulphur in the last. Color reddish brown and brownish black, re-
sembling blende. H. =4. Gr. — 3*46. From Hungary.
Kaneite is a manganese arsenide, of a grayish-white color, and
metallic lustre, which gives off alliaceous fumes. G.=5'55. From
Saxony.
Pyrolusite. — Manganese Dioxide.
Trimetric. In small rectangular prisms, more or less
modified. /A/— 93° 40'. Sometimes
fibrous and radiated or divergent. Of-
ten massive and in reniform coatings.
Color iron-black ; streak black, non-
metallic. H. — 2-2-5 G. = 4-8.
Composition. Mn 02 = Manganese
63-2, oxygen 36 -8^100. A minute
portion of it imparts to a borax bead
a deep amethystine color while hot,
which becomes red-brown on cooling. It yields no water
in a matrass.
Diff. Differs from psilomelane by its inferior hardness,
and from ores of iron by the violet glass with borax.
Obs. This ore is extensively worked in Thuringia, Mo-
ravia, and Prussia. It is common in Devonshire and Somer-
setshire, in England, and in Aberdeenshire. In the United
States it is associated with the following species in Ver-
mont, at Bennington, Brandon, Monkton, Chittenden, and
Irasburg ; it occurs also in Maine, at Conway, and Plain-
field in Massachusetts ; at Salisbury and Kent, in Conn.,
on hematite ; on Ked Island, in the Bay of San Francisco ;
at Pictou and Walton, Nova Scotia ; near Bathurst, in
New Brunswick.
MANGANESE. 189
The name pyrolusite is from the Greek pur, fire, and luo,
to wash, and alludes to its property of discharging the
brown and green tints of glass, for which it is extensively
used.
Besides the use just alluded to, this ore is extensively em-
ployed for bleaching, and for affording the gas oxygen to
the chemist.
Hausmannite. A manganese oxide, 2 Mn O + Mn 02, which contains
721 per cent, of manganese, when pure. Brownish black and sub-
metallic, occurring massive and in square octahedrons. H. =5-5*5.
G.=4'7. From Thuringia and Alsatia. Hetcerolite is a zinc-hausman-
nite, from Sterling Hill, N. J.
Braunite. An oxide of manganese, containing 69 per cent, of man-
ganese when pure. Color and streak dark brownish-black, and lustre
submetallic. Occurs in square octahedrons and massive. H. =6-65.
G. =4 '8. From Piedmont and Thuringia.
Manganite. A hydrous sesquioxide of manganese. Occurs massive
and in rhombic prisms. Color steel-black to iron-black. H.=4-4'5.
G. :=4-3-4-4. From the Hartz, Bohemia, Saxony, and Aberdeenshire.
It is found at several points in New Brunswick and Nova Scotia.
Psilomelane.
Massive and botryoidal. Color black or greenish-black.
Streak reddish or brownish-black, shining. H. =5-6. G.=
4-4-4.
Composition. Essentially manganese dioxide with a little
water, and also some baryta or potassa. The compound is
somewhat varying in its constitution. Before the blowpipe
like pyrolusifce, except that it affords water.
Obs. This is an abundant ore, and is associated usually
with the pyrolusite. It occurs at the different localities
mentioned under pyrolusite, and the two are often in alter-
nating layers ; it has been considered an impure variety of
the pyrolusite. The name is from the Greek psilos, smooth
or naked, and melas, black.
Pyrochroite. Hydrous manganese protoxide, of white color. From
Sweden. MnO2H,.
Pdugite. The manganese nodules found in many regions over the
bottom of the ocean. Affords, according to an analysis, about 40 per
cent, of MnOo, 27 ffe03, l:j of water lost at a red heat, along with 14
per cent, of silica and 4 of alumina ; 24'5 per cent, of water were
lost below 100° C. Probably a mixture.
Ghalcophanite. A hydrous oxide of manganese and zinc, in rhombo-
hedral crystals and stalactites ; from Sterling Hill, N. J.
190 DESCRIPTIONS OF MINERALS.
Wad. — Bog Manganese.
Massive, reniform or earthy ; also in coatings and dendri-
tic delineations. Color and streak black or brownish black.
Lustre dull, earthy. H. = l-6. G. — 3-4. Soils the fingers.
Composition. Consists of manganese dioxide, in varying
proportions, from 30 to 70 per cent., mechanically mixed
with more or less of iron sesquioxide; 10 to 25 per cent, of
water, and often several per cent, of oxide of cobalt or cop-
per. It is formed in low places from the decomposition of
minerals containing manganese. Gives off much water
when heated, and affords a violet glass with borax.
Obs. Wad is abundant in Columbia and Dutchess coun-
ties, N. Y., at Austerlitz, Canaan Centre, and elsewhere;
also at Blue Hill Bay, Dover, and other places in Maine ;
at Nelson, Gilmanton, and Grafton, N. H.; and in many
other parts of the country.
It may be employed like the preceding in bleaching, but
is too impure to afford good oxygen. It may also be used
for umber paint.
Lampadite, or Cupreous Manganese. A wad containing 4 to 18 per
cent, of copper oxide.
Triphylite.
Trimetric. In rhombic crystals, massive. Color green-
ish gray to bluish gray, but often brownish hlack externally
from the oxidation of the manganese present. Streak
grayish white. Lustre subresinous. H. =5. G. =3 "54-3 '6.
Composition, (JLi2 f R)3 08 P2, in which R stands for Fe
and Mn. A Bodenmais specimen afforded Phosphorus
pentoxide 44*19, iron protoxide 38*21, manganese protoxide
5-63, magnesia 2-39, lime 0'76, lithia 7 '69, soda 0'74, pot-
ash 0-04, silica 0 -40= 100-05. B.B. fuses very easily, color-
ing the flame a beautiful red, in streaks, with a pale bluish-
green on the exterior of the flame. Soluble in hydrochloric
acid.
Obs. Found at Rabenstein in Bavaria ; in Finland ; at
Norwich, Mass. ; Grafton, N. H.
LitMophilite, A salmon-colored manganese-lithium phospliate, al.
lied in composition to triphylite, but containing very little iroa
From Redding (near Branchville Depot), Conn.
MANGANESE. J^l
Triplite.
Trimetric. Usually massive, with cleavage in three di-
rections. Color blackish brown. Streak yellowish gray.
Lustre resinous ; nearly or quite opaque. H.=5-5-5 G =
3-4-38.
Composition. (Mn,Fe)308P2 + RF2, affording about 30
per cent, of manganese protoxide, 8 of fluorine. Fuses
easily to a black magnetic globule. B.B. imparts a violet
color to the hot borax bead. Dissolves in hydrochloric
acid.
Obs. From Limoges in France. Rather abundant at
Washington, Conn., and sparingly found at Sterling, Mass.
Heterosite, Alluaudite, Pseudotriplite, are regarded as results of
alteration, either of triphyline or of triplite.
Triploidite. A manganese-iron phosphate like triplite, but having
the fluorine replaced by the elements of water. From Redding, Conn.
Dickinsonite. An oil-green to olive-green manganese-iron-calcium
phosphate. From Redding, Conn.
Reddingite. A rose-pink hydrous manganese-iron phosphate. Mn,
Oe P2 + 3 aq, isomorphous with scorodite and strengite. Redding, Ct.
Fairfieldite, hydrous manganese-calcium phosphate. Ibid.
Hureaulite. Rose-colored to brownish-orange hydrous manganese-
iron phosphate. From Hureaux, France.
Rhodochrosite.— Manganese Carbonate.
Rhombohedral. E A 12= 166° 51'; like calcite in hav-
ing three easy cleavages, and in lustre. Color rose-red.
H. =3-5-4-5. G. = 3'4-3-7.
Composition. Mn 03 C = Carbonic acid 386, manganese
protoxide 61 '4=100. Part of the manganese often replaced
by calcium, magnesium or iron.
Obs. From Saxony, Transylvania, the Hartz, Ireland ;
Mine Hill, New Jersey ; Redding, Conn. ; Austin, Nevada ;
Placentia Bay, Newfoundland.
Rhodonite. A manganese silicate. See p. 247
General Remarks. Manganese is never used in the arts in the pure
state ; but as an oxide it is largely employed in bleaching. The im-
portance of the ore for this purpose depends on the oxygen it con-
tains, and the facility with which this gas is given up. As the ores
are often impure, it is important to ascertain their value in this re-
spect. This is most readily done by heating gently the pulverized ore
with hydrochloric acid, and ascertaining the amount of chlorine given
off. The chlorine may be made to pass into milk of lime, to form a
chloride, and the value of the chloride then tested according to the
usual modes. The amount of chlorine derived from a given quantity
DESCRIPTIONS OF MINERALS.
of muriatic acid depends not only on the amount of oxygen in the ore,
but also on the presence or absence of baryta and such other earths as
may combine with this acid. The binoxide of manganese, when pure,
affords 18 parts by weight of chlorine, to 22 parts of the oxide ; or 23^
cubic inches of gas from 22 grains of the oxide. The best ore should
give about three-fourths its weight of chlorine, or about 7,000 cubic
inches to the pound avoirdupois.
Iron ores containing some manganese are used for making spiegeleisen,
a hard highly crystallized pig-iron, containing a large amount of car-
bon and some manganese. A manganesian iron carbonate or siderite is
thus used, and also the franklinite of New Jersey.
Manganese is also employed to give a violet color to glass. The
sulphate and the chloride of manganese are used in calico printing.
The sulphate gives a chocolate or bronze color.
ALUMINUM.
The aluminum compounds among minerals include only
one oxide — a sesquioxide =41 03 — hydrated oxides, fluorides,
and, among ternaries, sulphates, phosphates, and numerous
silicates. There are no sulphides or arsenides, and no car-
bonate, with a single imperfectly understood exception.
The silicates are described in the following section. Many
aluminum compounds may be distinguished by means of a
blowpipe experiment, as explained 011 page 87.
Corundum.
Rhombohedral. R A R or r A r=8G° 4'. Cleavage some-
times perfect parallel with 0, and sometimes par-
allel to the rhombohedral faces. Usual in six-
sided prisms, often with uneven surfaces, and
sometimes so irregular that the form is scarcely
traceable. Occurs also granular. Colors blue,
and grayish-blue most common ; also red, yel-
low, brown, and nearly black ; often bright.
When polished on the surface 0, a star of six
rays, corresponding with the six-sided form of
the prism, is sometimes seen within the crystal.
Transparent to translucent. H. = 9, or next below the
diamond. Exceedingly tough when compact. G. =3*9-4*16.
Composition. A103= Oxygen 46-8, aluminum 53-2 = 100;
pure alumina. B.B. remains unaltered both alone and with
soda. The. fine powder moistened with cobalt nitrate and
ignited assumes a blue color.
COMPOUNDS OF ALUMINUM. 193
VARIETIES. The name sapphire is usually restricted, in
common language, to clear crystals of bright colors, used as
gems ; while dull, dingy-colored crystals and masses are
called corundum, and the granular variety of bluish-gray
and blackish colors containing much disseminated magne-
tite (whence its dark color) is called emery.
Blue is the true sapphire color. When of other bright
tints, it receives other names ; as oriental ruby, when red ;
oriental topaz, when yellow ; oriental emerald, when green ;
oriental amethyst, when violet, and adamantine spar, when
hair-brown. Crystals with a radiate chatoyant interior are
often very beautiful, and are called asteria, or asteriated
mppliire.
Diff. Distinguished readily by its hardness, exceeding all
species except the diamond, and scratching quartz crystals
with great facility.
Obs. The sapphire is often found loose in the soil. Meta-
morphic rocks, especially gneissoid mica schist, and granu-
lar limestone, appear to be its usual matrix. It is met with
in several localities in the United States, but seldom suffi-
ciently fine for a gem. A blue variety occurs at Newton,
K J., in crystals sometimes several inches long ; bluish and
pink, at Warwick, N. Y.; white, blue, and reddish crystals
at Amity, N. Y. ; grayish, in large crystals, in Delaware
and Chester counties, Pennsylvania ; pale blue crystals
have been found in bowlders at West Farms and Litchfield,
Conn. It occurs also in large quantities in North Carolina,
where crystals are numerous though rarely fit for jewelry,
and where one has been obtained weighing 312 pounds, and
having a reddish color outside and bluish-gray within ; also
in Cherokee County, Georgia ; in Los Angeles County, Cali-
fornia. Emery is mined at Chester, in Mass.
The principal foreign localities are as follows : blue, from
Ceylon ; the finest red from the Capelan Mountains in the
kingdom of Ava, and smaller crystals from Saxony, Bohemia
and Auvergne ; corundum, from the Carnatic, on the Mala-
bar coast, and elsewhere in. the East Indies ; adamantine
spar, from the Malabar coast ; emery, in large bowlders
from near Smyrna, and also at Naxos and several of the
Grecian islands.
The name sapphire is from the Greek word sapplieiros,
the name of a blue gem. It is doubted whether it included
the sapphire of the present day.
194 DESCRIPTIONS OF MINERALS.
Next to the diamond, the sapphire in some of its varieties
is the most costly of gems. The red sapphire is much more
highly esteemed than those of other colors. A crystal of
one, two or three carats is valued at the price of a diamond
of the same size. They seldom exceed half an inch in their
dimensions. Two splendid red crystals, as long as the little
finger and about an inch in diameter, are said to be in the
possession of the king of Arracan. The largest oriental ruby
known was brought from China to Prince Gargarin, gov-
ernor of Siberia ; it afterward came into the possession of
Prince Menzikoff, and constitutes now a jewel in the im-
perial crown of Russia.
Blue sapphires occur of much larger size. According to
Milan, Sir Abram Hume possessed a crystal which was three
inches long. One of 9-51 carats is stated to have been found
in Ava.
Corundum and emery are crushed to a powder of differ-
ent degrees of fineness, and make the abrading and polishing
jpiaterial called in the shops emery. The iron oxide of true
emery diminishes its hardness, and consequently its abrasive
power ; pulverized corundum is more valuable and efficient
in abrasion.
Diaspore. Hydrated aluminum of the formula Al O4 H2= Water 14 '9,
alumina 85 '1=100. Usually found assotiated with corundum. Crys-
tals usually thin and flattened. Color whitish, grayish, pinkish, etc.
Very brittle. Translucent. H. 6 '5-7. G. 3 '5. From the Urals ;
Schemnitz ; Chester, Mass. ; Chester County, Pa. ; North Carolina.
< Gibbsite (Hydrargillite). Hydrated alumina ; Al 06 H«= water 34 '5,
alumina 65*5=100. Occurs in hexagonal crystals ; more commonly in
stalactitic aiad mammillary forms, with smooth surface, looking like
chalcedony. Color white, grayish and greenish -white ; translucent,
sometimes transparent when in crystals. H. =2'5-3'5; G.=2'3-2*4.
Near Slatoust in the Ural ; in Asia Minor ; on corundum at Unionville,
Pa. ; at Richmond, Mass, in stalactitic forms ; in Orange County, N. Y.
Hydrotalcite ( Volknerite, Houghite). A soft pearly mineral, contain-
ing alumina, magnesia, and water. Accompanies spinel, and some-
times a result of the alteration of spinel crystals. Occurs near Sla-
toust ; at Snarum, Norway ; near Oxbow in Rossie, St. Lawrence
County, N. Y. (the variety Houghite}.
Spinel.
Isometric. In octahedrons, more or less modified. Fig-
ure 4 represents a - twin crystal. Occurs only in crystals ;
cleavage octahedral, but difficult.
Color red, passing into blue, green, yellow, brown, and
.COMPOUNDS OF ALUMINUM.
195
black. The red shades often transparent and bright ; the
dark shades usually opaque. Lustre vitreous. II. =8.
G.=3-5-4'l.
2.
4.
Composition. MgAl 04=Mg 0 -f- A103= Alumina 72, mag-
nesia 28 = 100. The aluminum is sometimes replaced in
part by iron, and the magnesium often in part by iron, cal-
cium, manganese and zinc. Infusible ; insoluble in acids.
VARIETIES. The following varieties of this species have
received distinct names : the scarlet or bright red crys-
tals, spinel ruby ; the rose-red, balas-ruby ; the orange-red,
rubicelle; the violet, almandine-ruby ; the green, cliloro-
spinel ; while the black varieties are called pleonaste. Pleo-
naste crystals contain sometimes 8 to 20 percent, of oxide
of iron. Picotite is a variety containing 7 per cent, of
chromium oxide.
Diff. The form of the crystals and their hardness dis-
tinguish the species. Garnet is fusible. Magnetite is at-
tracted by the magnet. Zircon has a higher specific gravity
and is not so hard. The red crystals often resemble the
true ruby (red corundum), but the latter are never in octa-
hedrons.
Obs. Occurs in granular limestone ; also in gneiss and
volcanic rocks. At numerous places in the adjoining coun-
ties of Sussex in New Jersey, and Orange county, of various
19C DESCRIPTIONS OF MINERALS.
colors from red to brown and black ; especially at Frank-
lin, Newton and Sparta, in the former, and in Warwick,
Amity and Edenville, in the latter. The crystals are octa-
hedrons, and often grouped or disseminated singly in gran-
ular limestone. One crystal, found at Amity by Dr. Heron,
weighs 49 pounds. The limestone quarries of Bolton, Box-
borough, Chelmsford and Littleton, Mass., afford a few
crystals.
Crystals of spinel are occasionally soft, having under-
gone a change of composition approaching steatite in all
characters except form. They are true pseudomorplis. They
are met with in Sussex and Orange counties. Other spinel
pseudomorplis consist of hydrotalcite (see preceding page).
Uses. The fine colored spinels are much used as gems.
The red is the' common ruby of jewelry, the oriental rubies
being sapphire.
Gahnite is a spinel in which zinc takes the place of part or all of the
magnesium; when all, it is called Automolite. Color dark green or green-
ish black. H. =7-5-8. G.— 4-4-6. When fused with sufficient soda,
B.B. on coal a white coat of zinc oxide is deposited, which is yellow
when hot. B.B. infusible. At Franklin, N. J., and at the Canton
mine in Georgia. Occurs in granite at Haddam with beryl, chryso-
beryl, garnet, etc. In Sweden, near Fahlun, in talcose slate.
Dysluite. A variety of gahnite containing oxide of manganese.
Color yellowish or grayish-brown. H.r=7'5-8. G.=4'55. Composi-
tion, Alumina 30'5, zinc oxide 16'8, iron sesquioxide 41 '9, manganese
protoxide 7 '6, silica 3, water 0'4. From Sterling, N. J., with frank-
linite and troostite.
Kreittonite is a zinc-iron gahnite.
Hercinite is a spinel affording on analysis alumina and iron protoxide,
with only 2 '9 per cent, of magnesia.
Chrysoberyl.
Trimetric. /A 7=129° 38'. Also in compound crystals,
as in fig. 2. Crystals sometimes thick ; often tabular.
Color bright green, from a light shade to emerald-green ;
rarely rasptierry or columbine-red by transmitted light.
Streak uncolored. Lustre vitreous. Transparent to trans-
lucent, H. = 8'5. G. =3-5-3 -8.
Composition. Be Al 04 = Alumina 80 -2, glucina 19;8 = 100.
A little iron is sometimes present. B.B. infusible and un-
altered.
Alexandrite is an emerald-green variety from the Urals,
colored by chrome, bearing the same relation to ordinary
chrysoberyl as emerald to beryl. Fig. 7 is of this variety.
COMPOUNDS OF ALUMINUM.
197
Diff. Near beryl, but distinct in not being regularly hex-
agonal in crystallization.
Obs. Chrysoberyl occurs in the United States in granite
at Haddam, Conn., and Greenfield, near Saratoga, N. Y.,
associated with beryl, garnet, etc. ; in Norway, Maine.
1.
The name chrysoberyl is from the Greek chrysos, golden,
and beryllos, beryl.
The crystals are seldom sufficiently pellucid and clear
from flaws to be valued in jewelry ; but when of fine qual-
ity, it forms a beautiful gem, and is often opalescent.
Fluorides of Aluminum.
Cryolite. In snow-white masses, having rectangular cleavages, and
remarkable for melting easily in the flame of a candle, to which its
name (from the Greek kruos, ice) alludes. H.=2-o. G.=2'95. It is
a sodium-aluminum fluoride. Prom Greenland.
Chiolite and Chodnefflte are near cryolite in composition and charac-
ters. Arksutite, Gearksutite, Pachnolite, Thomsenolite are related fluor-
ine compounds which occur associated with the Greenland cryolite.
From Siberia.
Fluellite. From Cornwall, in minute white rhombic octahedrons.
Contains fluorine and aluminum.
Alunogen.— Hydrous Aluminum Sulphate.
In silky efflorescences, and crusts of a white color, having
a taste like common alum. H. —1-5-2. G. =1-6-1 '8.
Composition. Al 0,2 S3 4- ISaq = Sulphur trioxide 36-0,
alumina 15-4, water 48-0 = 100.
Obs. A common efflorescence in solfataras of volcanic
regions, and also often occurring in shales of coal regions
and other rocks containing pyrite ; the oxidation of the
pyrite — an iron sulphide — affords sulphuric acid, which
acid combines with* the alumina of the shale.
198 DESCRIPTIONS OF MINERALS?.
. Alums Frequently the sulphuric acid resulting from the oxidation
of a sulphide, or in some other way, combines also with the iron,
magnesia or potash or soda of the shale or other rock, as well as the
alumina, and so makes other kinds of aluminum sulphate.
Combining thus with potash it produces common alum called Kali-
nite or potash alum, whose formula is K2A13 02< S4 + 18 aq ; with am-
monia, it forms an ammonia-alum, named Tschermigite ; with iron,
iron alum, called Halotrichite ; with soda, a soda-alum, Mendozite ;
with magnesia a magnesia-alum, Pickeringite ; with manganese, a
manganese-alum, Apjohnile and Bosjemanite. The formulas of these
alums are alike in atomic proportions, excepting in the amount of
water, which varies from 18 aq to 24 aq.
Shale containing alunogen or any of the alums is often called alum
shale. Such rocks, whether shales or of other kinds, are often quar-
ried and lixiviated for the alum they contain or will afford. The rock
is first slowly heated after piling it in heaps, in order to decompose
the remaining pyrites and transfer the sulphuric acid of any iron sul-
phate to the alumina and thus produce the largest amount possible of
aluminum sulphate. It is next lixiviated in stone cisterns. The lye
containing this sulphate is afterwards concentrated by evaporation,
and then the requisite proportion of potassium in the form of the sul-
phate or chloride is added to the hot solution. On cooling, the alum
crystallizes out, and is afterwards washed and re-crystallized. The
mother liquor left after the precipitation is revaporated to obtain the
remaining alum held in solution. This process is carried on exten-
sively in Germany, France, at Whitby in Yorkshire, Hurlett and
Campsie, near Glasgow, in Scotland. Cape Sable in Maryland affords
large quantities of alum annually. The slates of coal beds are often
used to advantage in this manufacture, owing to the decomposing
pyrites present. At Whitby, 130 tons of calcined schist give one ton
of alum. In France, ammoniacal salts are used instead of potash,
and an ammonia alum is formed.
Alum is also manufactured from cryolite (see p. 197), which is ob-
tained from Greenland.
Alunite. — Alum Stone.
Rhombohedral, with perfect basal cleavage*. Also mas-
sive. Color white, grayish, or reddish. Lustre of crystals
vitreous, or a little pearly on the basal plane. Transparent
to translucent. H. =4. G. = 2-5S-2'75.
Composition. K2 Al 022 S4-fG aq= Sulphuric trioxide 38*5,
alumina 371, potash 11'4, water 13-0^100. B.B. decrepi-
tates and is infusible ; gives reaction for sulphur.
Diff. Distinguished by its infusibility, in connection with
its complete solubility in sulphuric acid without forming a
jelly-
Obs. Found in rocks of volcanic origin at Tolfa, near
Rome ; and also at Beregh and elsewhere in Hungary.
When it is calcined the sulphates become soluble, and the
COMPOUNDS OF ALUMINUM. 199
alum is dissolved out. On evaporation the alum crystallizes
from the fluid in cubic crystals. This is called Roman alum,
and is highly valued by dyers, because, although the crystals
are colored red by iron oxide, no iron is chemically com-
bined with the salt as is usual in common alum.
Aluminite (Webstcrite). Another hydrous aluminum sulphate, in
compact reniform masses, and tasteless. From New Haven, in Sussex ;
Epernay, in France ; and Halle, in Prussia.
Lcewiyite is a potassium-aluminum sulphate, containing half the
water of potash alum.
Ambly gonite. — Lithium- Aluminum Phosphate.
Triclinic, with cleavages unequal in two directions, mak-
ing an angle with one another of 104£°. Lustre vitreous
to pearly and greasy. Color pale mountain-green, or sea-
green to white. Translucent to subtransparent. H. = 6.
G.= 3-3-11.
Composition. A lithium-aluminum phosphate, Al OgP2 +
1£ (Li, Na) F. B.B. fuses very easily with intumescence,
coloring the flame yellowish red to rich carmine-red, owing
to the lithia present, and traces of green owing to the phos-
phoric acid. Gives the reaction also for fluorine.
Obs. Occurs in Saxony and Norway.
HebroniU is a closely related mineral from Hebron and Mount Mica
in Maine, and from Redding in Connecticut.
Herderite is supposed to be an anhydrous calcium-aluminum phos-
phate with fluorine.
Durangite. An anhydrous arsenate of an orange-red color, contain-
ing aluminum, sodium, iron, and some manganese, with over 7 per
cent, of fluorine. From Durango, Mexico, where it occurs with cas-
siterite or tin ore.
Lazulite.
Monoclinic. In crystals and also massive, of an azure-blue
color. H.=5-6. G. = 3'057.
Composition. RA1 09 P2 4- aq= Phosphorus pentoxide 46' 8,
alumina 34'0, magnesia 13-2, water 6 '0=100. B.B. in the
closed tube whitens and yields water ; with cobalt solution
the color is restored; in the forceps whitens, swells, cracks,
and falls to pieces without fusion, coloring the flame bluish-
green.
Obs. From Salzburg, Styria; \Vermland, Sweden; Crowder
Mount, Lincoln County, JNT. C. ; and on Graves Mountain,
Lincoln County, Georgia.
200 DESCRIPTIONS OF MINERALS.
Variscite (Peganite, Callainite) is another hydrous aluminum phos-
phate ; it is of a light green color, of various shades, to deep emerald-
green. From Montgomery County, Arkansas, and from Colorado ; also
from Messbach, in Saxon Voigtland. Fischerite, is a related mineral.
Turquois.
In opaque reniform masses without cleavage; of a bluish-
green color, and somewhat waxy lustre. II. — 6. G. — 2-6
2»Q
O.
Composition. Phosphorus pentoxide 32 *G, alumina 46*9,
water 20*5 = 100. 13. B. infusible, but becomes brown and
colors the flame green ; soluble in hydrochloric acid ; moist-
ened with the acid it gives a momentary bluish green color
to the flame, owing to the copper that it contains.
Diff. Distinguished from bluish-green feldspar, which it
resembles, by its infusibility and the reactions for phos-
phorus.
Obs. Turquois is brought from a mountainous district in
Persia, not far from Nichabour ; and, according to Agaphi,
occurs in veins that traverse the mountain in every direc-
tion.
The Callais of Pliny was probably turquois. Pliny, in
his description of it, mentions the fable that it was found
in Asia, projecting from the surface of inaccessible rocks,
whence it was obtained by means of slings.
Turquois receives a fine polish and is highly esteemed as
a gem. In Persia it is much admired, and the Persian
king is said to retain for himself all the large and more
finely tinted specimens. The occidental or lone turquois,
is fossil teeth or bones, colored with a little phosphate of
iron. Green malachite is sometimes substituted for turquois,
but it is of little hardness and has a different tint of color.
The stone is so well imitated by art as scarcely to be detected
except by chemical tests. The imitation is much softer
than true turquois.
Childrenite. A hydrous phosphate containing aluminum, iron, with
little manganese. Found in trimetric crystals in Devonshire and
Cornwall ; also at Hebron in Maine.
Eosphorite. Has the crystalline form and nearly the angles of chil-
drenite, and contains the same constituents, but differs in being
essentially a hydrous phosphate of manganese with little iron. From
Bedding, Connecticut.
Henwoodite is a hydrous aluminum phosphate from Cornwall, con-
taining also copper.
COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 201
Wavellite.
Trimetric. Usually in small hemispheres a third or half
an inch across, attached to the
surface of rocks, and having a
finely radiated structure within ;
when broken off they leave a stel-
late circle on the rock. Some-
times in rhombic crystals.
Color white, green, or yellowish and brownish, with a
somewhat pearly or resinous lustre. Sometimes gray or
black. Translucent. H. =3*5-4. G. = 2*3. . •
Composition. Al3Oi9P4 + 12aq = Phosphorus pentoxide
35-16, alumina 38-10, water 26 74 = 100. 1 to 2 per cent,
of fluorine is often present, replacing the oxygen. B.B.
whitens and swells, but does not fuse. Colors the flame
green, especially if previously moistened with sulphuric
acid. Moistened with cobalt nitrate, assumes a blue color
after ignition ; gives much water in the closed glass tube.
Diff. Distinguished from the zeolites, some of which it
resembles, by giving the reaction of phosphorus, and also
by dissolving in acids without gelatinizing. Cacoxene, to
which it is allied, becomes dark reddish-brown before the
blowpipe, and does not give the blue with cobalt nitrate.
Obs. Occurs at the slate quarries of York County, Pa.,
and also at Washington Mine, Davidson County, N. C. ; at
Magnet Cove, Ark. It was first discovered by Dr. Wavel,
in clay slate in Devonshire. Occurs also in Bohemia and
Bavaria.
Zepliaromchite is near wavellite.
Mellite or Hon^y stone. In square octahedrons, looking like a honey,
yellow resin ; may be cut with a knife. It is an aluminum mellate.
Found in Tkuringia, Bohemia, Moravia, etc.
Dawsonite. Hydrous aluminum-calcium carbonate, from a felsyte
dike near Montreal.
CERIUM, YTTRIUM, ERBIUM, LANTHANUM, DIDYMIUM.
Known in nature in the condition of fluorides, tantalates,
columbates, phosphates, or carbonates, and also as constitu-
ents in several silicates.
Yttrocerite.
Massive, of a violet-blue color, somewhat resembling a
202 DESCRIPTIONS OP MINERALS.
purple fluor- spar ; sometimes reddish-brown. Opaque.
Lustre glistening. II. = 4-5. G. = 3'4-3'5.
(Composition. Fluorine 25'1, lime 47*6, cerium protox-
ide 18*2, and yttria 9*1. Infusible alone before the blow-
pipe.
Obs. From Finbo and Broddbo, near Fahlun, in Sweden,
with albite and topaz in quartz. Also from Mt. Mica,
Maine ; Massachusetts, probably in Worcester County; and
from Amity, Orange County, N.Y.
Fluocerite and Fluocerine are other fluorides containing cerium, from
Sweden.
Samarskite.
Trimetric. /A 7=122° 46'. Usually massive, without
cleavage, with a velvet-black color and shining submetallic
lustre. Streak dark-reddish brown. Opaque. H.= 5*5-6.
G. = 5-C-5-8.
Composition. Analyses of the American afford Columbia
and tantalic pentoxide, with sesquioxides of yttrium (12-15
per cent.), cerium, iron, and oxide of uranium. In the
closed tube decrepitates and glows. B.B. fuses on the
edges to a black glass. With salt of phosphorus in both
flames, an emerald-green bead.
Obs. Occurs at Miask, in the Ural ; also in masses,
sometimes weighing many pounds, at the Mica mines of
Western North Carolina, along with columbite. •
Noldite is near samarskite, but contains 4 "62 of water.
Fergusonite. A hydrous columbate of yttrium, erbium, cerium.
Color brownish black ; lustre dull, but brilliantly vitreous on a sur-
face of fracture. B.B. infusible, but loses its color. From Sweden,
Cape Farewell, Greenland, and Rockport, Mass.
Kochelite is near fergusonite.
Yttro-tantalite. A tantalate and columbate of yttrium, erbium, and
iron. The different varieties are the black, the yellow, and brown or
dark-colored. They are infusible. From Ytterby, Sweden, and at
Broddbo and Finbo, near Fahlun.
Euxenite. A columbate and tantalate of yttrium, uranium, erbium,
and cerium. Massive. Color brownish black. Streak reddish brown,
B.B. infusible. From Norway; also from N. Carolina.
Sipylite. A columbate and tantalate of erbium and yttrium, re-
sembling fergusonite in aspect. From Amherst County, Va.
Pyrochlore, Microlite, Disanalyte, under CALCIUM, p. 214.
jEschynite. In crystals, black to brownish yellow ; lustre resinous
to submetallic ; streak gray to yellowish brown or black. H. =5-6.
G. =4'9-5 1. A columbate and titanate of cerium, thorium, and lan-
thanum. From Miask, in the Urals, in feldspar with mica and zircon.
Polymignite and Polycrase. Related to seschynite,
COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 203
Rogersite. A hydrous columbate of yttria, in whitish crusts, on
samarskite. From N. Carolina.
Monazite.
Monoclinic. In modified oblique rhombic prisms ; I/\I
= 93° 10'. Perfect and brilliant basal cleavage. Observed
only in small imbedded crystals.
Color brown, brownish red ; subtransparent to nearly
opaque. Lustre vitreous inclining to resinous. Brittle.
H. = 5. G. =4-8-51.
Composition. A phosphate containing cerium, lantha-
num, yttrium, didymium and thorium, with also a little
tin, mano-anese, and lime. B.B. it colors the flame green
when moistened with sulphuric acid and heated. Difficultly
soluble in acids.
Diff. The brilliant easy transverse cleavage distinguishes
monazite from sphene.
Obs. Occurs near Slatoust, Eussia. In the United
States it is found in small brown crystals, disseminated
through a mica slate at Norwich, Conn. ; also at Chester,
Conn., and Yorktown, Westchester County, N. Y.
Cryptolite. A cerium phosphate in minute prisms (apparently six.
sided), found with the apatite of Arendal, Norway. Color pale wine-
yellow. G.=4'6.
Churchite. A phosphate of cerium, didymium and calcium ; from
Cornwall.
Xenotime, An yttrium phosphate having a yellowish-brown color,
pale brown streak, opaque, and resinous in lustre. Crystals square
prisms, with perfect lateral cleavage. H. =4-5. G. =4'G. Infusible
alone before the blowpipe ; insoluble in acids. From Lindesnaes,
Norway ; Ytterby, Sweden ; gold washings of Clarkesville, Ga., and
McDowell County, N. C.
Parisite. Is a carbonate containing cerium, lanthanum, and didy«
rnium, with fluorine. From New Granada.
Lantlianite. Occurs in thin minute tables or scales of whitish or
yellowish color, and is a hydrous lanthanum carbonate. From Bast-
nas, Sweden, and Saucon Valley in Lehigh County, Pa.
Tengerite. An yttrium carbonate. Found in thin coatings at Yt-
terby, Sweden.
Rliabdophane, A didymium and erbium phosphate ; from Corn-
wall, with sphalerite (blende), which it resembles.
Rutherfordite. A blackish-brown vitreo-resinous mineral. From
the gold mines of Rutherford County, N. C.
Allanite, Gadolinite, Keilhauite, and Tscheffkinite, are silicates con-
taining either cerium or yttrium.
204 DESCRIPTIONS OF MINERALS.
MAGNESIUM.
Magnesium occurs, in nature, as an oxide or hydrated
oxide, and in the condition of sulphate, borate, nitrate,
phosphate, carbonate and silicate.
The sulphates and nitrate of magnesia are soluble in
water, and are distinguished by their bitter taste ; the
other native magnesian salts are insoluble. The presence
of magnesia, when no metallic oxides are present, is indi-
cated by a blowpipe experiment, explained on page 87.
Periclasite.— Periclase. Magnesium Oxide.
Isometric. In small grayish to dark-green imbedded
crystals, with cubic cleavage. H. nearly G. G.— 3-674.
Composition. Mg 0 (or the same as for magnesia alba of
the shops), with a little iron. B.B. infusible. Soluble in
acids without effervescence.
From Mount Somma, Vesuvius, Italy.
Brucite. — Magnesium Hydrate.
Ehombohedral. In foliated hexagonal prisms and plates;
structure thin foliated, and thin laminae easily separated
and translucent ; flexible but not elastic. Also fibrous.
Lustre pearly. Color white, often grayish or greenish.
H.=2-5. G.=2'35.
Composition. Mg02H2=: Magnesia 69-0, water 31-0=100.
B.B. infusible, but becomes opaque and alkaline. Soluble
in hydrochloric acid without effervescence.
Diff. It resembles talc and gypsum, but is soluble in
acids ; it differs from heulanditc and stilbite also by its in-
fusibility.
Obs. Occurs in serpentine at Hoboken, N. J. ; in Rich-
mond County, N. Y. ; in Dutchess County, 1ST. Y. , at
Brewster's ; at Texas, in Pennsylvania ; also at Swinaness,
in Unst, one of the Shetland Isles.
The fibrous variety has been called nemalite; it resembles
amianthus ; it occurs at Hoboken.
Hydromagnesite. A pearly crystalline, or earthy, white, hydrous
carbonate of magnesia, from Hoboken, N. J., Texas, Pa., and elsewhere.
Spinel contains oxygen and magnesium along with aluminum. See
page 195. Magnesium is also present in some magnetite, a variety of
which is called magnoferrite.
COMPOUNDS OF MAGNESIUM. 203
Chlwmagnesite. A magnesium chloride from Vesuvius.
Carnallite. A hydrous magnesium-potassium chloride.
Tachydrile. A hydrous magnesium-calcium chloride.
Epsomite. — Epsom Salt. Magnesium Sulphate.
Trimetric. /A 7= 90° 34'. Cleavage perfect parallel with
the shorter diagonal. Usually in fibrous crusts, or botry-
oidal masses, of a white color. Lustre vitreous to earthy.
Very soluble, and taste bitter and saline.
Composition. Mg 04 S + 7aq = Sulphur trioxide 32*5, mag-
nesia 16'3, water 51*2 = 100. Liquefies in its water of crys-
tallization when heated. Gives much water which has an
acid reaction, in the closed glass tube. B.B. on charcoal
fuses, but finally gives an infusible mass that turns pink
when moistened with cobalt nitrate and ignited.
Diff. The fine spicula-like crystalline grains of Epsom
salt, as it appears in the shops, distinguish it from Glauber
salt, which occurs usually in thick crystals.
Obs. The floors of the limestone caves of the West often
contain Epsom salt in minute cr}rstals mingled with the
earth. In the Mammoth Cave, Ky., it adheres to the roof
in loose masses like snowballs. It occurs as an efflores-
cence in the galleries of mines and elsewhere. The fine
efflorescences suggested the old name hair-salt.
• At Epsom, in Surrey, England, it occurs dissolved in min-
eral springs, and from this place the salt derived the name
it bears. It occurs at Sedlitz, Aragon, and other places in
Europe ; also in the Cordilleras of Chili ; and in a grotto in
Southern Africa, where it forms a layer an inch and a half
thick.
Its medical uses are well known. It is obtained for the
arts from the bittern of sea-salt works, and quite largely
from magnesian calcium carbonate, by decomposing it with
sulphuric acid. The sulphuric acid takes the lime and
magnesia, expelling the carbonic acid ; and the sulphate of
magnesium remaining in solution is poured off from the cal-
cium sulphate, which is insoluble. It is then crystallized by
evaporation.
Polylialite. A brick-red saline mineral, with a weak bitter taste,
occurring in masses which have a somewhat fihrous appearance. A
hydrous calcium- magnesium sulphate.
Kieserite. A hydrous magnesium sulphate ; from Stassfurt.
Picromeride. A hydrous potassium - magnesium sulphate ; from
Stassfurt.
206
DESCRIPTIONS OF MINERALS.
Bladite. A hydrous sodium -magnesium sulphate ; from the salt
mines of Ischl, and near Mendoza.
Jjoewcite. A hydrous sodium magesium sulphate ; from Ischl. Con'
tains more sulphur trioxide than Bleed ite.
Isometric.
1.
traces.
Boracite. — Magnesium Borate.
Cleavage octahedral ; but only
Usual in cubes with only the
alternate angles replaced ; or
having all replaced, but four
of them different from the
other four. The crystals are
translucent and "seldom more
than a quarter of «n inch
through. Also massive. Color white or grayish ; sometimes
yellowish or greenish. Lustre vitreous. H. — 7 when in
crystals, but softer when massive. G. =2-97. Becomes
electric when heated, the opposite angles of the cube be-
coming of opposite poles.
Composition. Mg3 015 B8 + JMg C12= Boron trioxide 62-0,
magnesia 31'0, chlorine 7*0=100. B.B. fuses easily with in-
tumescence coloring the flame green. The fused globule
becomes crystalline on cooling. Dissolves in hydrochloric
acid, and moistened with cobalt nitrate turns pink on igni-
,tion.
Diff. Distinguished readily by its form, high hardness,
And pyro electric properties.
Obs. Boracite is found only with gypsum and common
salt. It occurs near Luneberg in Lower Saxony, and near
Kiel in the adjoining duchy of Holstein, also at Stassfurth,
Prussia.
Rhodizite. Resembles horacite in its crystals, hut tinges the blow-
pipe flame deep red. It is supposed to be a lime-boracite. Occurs
with the red tourmaline of Siberia. Ludwigite. A magnesium-iron
borate ; fibrous and dark green to black.
Szuibelyite. A hydrous magnesium borate, from Southeastern
Hungary
Warwickite. In rhombic prisms of 93° to 94°, hair-brown to black
with sometimes a copper-red tinge. A magnesium titanium borate ;
from granular limestone of Edenville, N. Y.
Sussexite. A hydrous magnesium-manganese borate. Fibrous and
pearly. G=3 42. from Mine Hill. Franklin Furnace, Sussex Co., N. J.
Nttromagnesite. Occurs in white deliquescent efflorescences, having
a bitter taste, associated with calcium nitrate, in limestone caverns. It
is used, like its associate, in the manufacture of saltpetre.
Wugnerite. A magnesium fluo-phosphate, occurring in yellowish or
COMPOUNDS OF CALCIUM. 20?
frayish oblique rhombic prisms. Insoluble. H. =5-5 '5. G.^3'1
rom Salzburg, Austria. Kjeralfine is near wagnerite.
Hcernisite and ficessleritc are hydrous calcium arsenates.
Luneburgite. A magnesium boro-phosphate, from Liineburg.
Magnesite.— Magnesium Carbonate.
Rhombohcdral. R : 72=107° 29'. Cleavage rhomboliedral,
perfect. Often massive, either granular, or compact and
porcelain-like, in tuberose forms ; also fibrous.
Color white, yellowish or grayish-white, or brown. Lus-
tre vitreous ; fibrous varieties often silky. Transparent to
opaque. H.- 3— 4'5. G. = 3.
Composition. Mg05C = Carbon dioxide 52*4, magnesia
47-6^100. Infusible before the blowpipe. After ignition
has an alkaline reaction. Nearly insoluble in cold dilute
hydrochloric acid, but dissolves with effervescence in hot.
Diff. Kesembles some varieties of calcite and dolomite ;
but 'from a concentrated solution no calcium sulphate is
precipitated on adding sulphuric acid. The fibrous variety
is distinguished from other fibrous minerals by its efferves-
c.ence in hot acid, which shows it to be a carbonate.
Obs. Magnesite *is usually associated with magnesian
rocks, especially serpentine. At Hoboken, N. J., it occurs
in this rock in fibrous seams ; similarly at Lynnfield, Mass.;
and in Canada, at Bolton, imperfectly fibrous, traversing
white limestone.
When abundant it is a convenient material for the manu-
facture of magnesium sulphate or Epsom salt, to make
which, requires simply treatment with sulphuric acid.
Ilydromagncsite. A hydrous magnesium carbonate. Occurs with
serpentine, at Hoboken, but more abundantly in Lancaster Co. , Penn.
Dolomite. A magnesium and calcium carbonate. See page 219.
CALCIUM.
Calcium exists in nature in the state of fluorite, and this
is its only binary compound. It occurs in ternaries in the
state of sulphate, borate, columbate, phosphate, arsenate,
carbonate, titanate and silicate. The carbonate (calcite and
limestone) is one of the three most abundant of minerals.
The fluoride and sulphate, and some silicates, are also of
very common occurrence.
208
DESCRIPTIONS OP MINERALS.
With the exception of the calcium nitrate, none of the
native salts of lime are soluble in water except in small
proportions. They give no odor, and no metallic reaction
before the blowpipe ; but they tinge the flame red, and
many of them give up a part of their acid constituent, and
become caustic and react alkaline. The specific gravity is
below 3 '2, and hardness not above 5.
Fluorite. — Fluor Spar. Calcium Fluoride.
Isometric. Cleavage octahedral, perfect. Commonly in
crystals ; rarely fibrous ; often compact, coarse or fine gran-
ular. Figures 1 to 4 repffesent common forms.
3.
Colors usually bright ; white, or some shade of light
green, purple, or clear yellow are most common ; rarely
rose-red and sky-blue ; colors of massive varieties often
banded. Transparent, translucent or subtranslucent. H = 4.
G. =3-3 '26. Brittle.
Composition. CaF2=Fluorine 48*7, calcium 51 '3 — 100.
Phosphoresces when gently heated in the dark, affording
light of different colors ; in some varieties emerald-green ;
in others, purple, blue, rose-red, pink, or orange. B.B.
decrepitates, and ultimately fuses to an enamel, which pos-
sesses an alkaline reaction ; pulverized and moistened with
sulphuric acid, hydrofluoric acid gas is given off which cor-
rodes glass. The name Clilorophane has been given to the
variety that affords a bright green phophorescence.
Diff. In its bright colors, fluorite resembles some of the
gems, but its softness and its easy octahedral cleavage when
crystallized at once distinguish it. Its strong phosphores-
cence is a striking characteristic; and also its affording
COMPOUNDS OF CALCIUM. 209
easily, with sulphuric acid and heat, a gas that corrodes
glass.
Obs. Fluorite occurs in gneiss, mica schist, clay slate,
limestone, and sparingly in beds of coal either in veins
or occupying cavities, or as imbedded masses. It is the
gangue in some lead mines.
Cubic crystals of a greenish color, over a foot each way,
have been obtained at Muscolonge Lake, St. Lawrence
County, N. Y. ; near Shawneetown on the Ohio, a beautiful
purple fluor in grouped cubes of large size is obtained from
limestone and the soil of the region ; at Westmoreland, N".
H., at the Notch in the White Mountains, Blue Hill Bay,
Maine, Putney, Vt., and Lockport, N. Y., are other locali-
ties. The chlorophane variety is found with topaz at Trum-
bull, Conn.
In Derbyshire, England, fluor spar is abundant, and hence
it has received the name of Derbyshire spar. It is a com-
mon mineral in the mining districts of Saxony.
Calcium fluoride also exists in the enamel of teeth, in
bones and some other parts of animals ; also in certain parts
of many plants ; and by vegetable or animal decomposition
it is afforded to the soil, to rocks, and also to coal beds in.
which it has been detected.
Massive fluor receives a high polish, and is worked into
vases, candlesticks and various ornaments, in Derbyshire,
England. Some of the varieties from this locality, consist-
ing of rich purple shades banded with yellowish white, are
very beautiful. The mineral is difficult to work because
brittle. Fluor spar is also used for obtaining hydrofluoric
acid, which is employed in etching. To etch glass, a pic-
ture, or whateverdesign it is desired to etch, is traced in
the thin coating of wax with which the glass is first covered;
a very small quantity of the liquid hydrofluoric acid is then
washed over it ; on removing the wax, in a few minutes, the
picture is found to be engraved on the glass. The same
process is used for etching seals, and any siliceous stone
will be attacked with equal facility. This application of
fluor spar depends upon the strong affinity between fluorine
and silicon. Fluor spar is also used as a flux to aid in re-
ducing copper and other ores, and hence the
£10 DESCRIPTIONS OF MINERALS.
Gypsum.— Hydrous Calcium Sulphate.
Monoclinic. /A 7=143° 42' ; 22A2i + lH° 42'. Figure
2 represents a common twin (or arrow-head) crystal. Cleav-
age parallel to i-l very easy, affording
thin pearly laminae ; parallel to 0, im-
perfect, giving a vitreous surface ; par-
allel to /, fibrous. Occurs also in lam-
inated masses, often of large size ; in
fibrous masses, with a satin lustre ; in
stellated or radiating forms consisting of
narrow laminae ; also granular and com-
pact.
When pure and crystallized it is as clear and pellucid as
glass, and has a pearly lustre. Other varieties are gray, yel-
low, reddish, brownish, and even black, and opaque. 1-1.=
1 '5-2,orso soft as to be scratched by the finger-nail. G. = 2'33,
The plates bend in one direction and are brittle in another.
Composition. Ca 04S + 2 aq— Sulphur trioxide 4(ro, lime
32-6, water 20 '9 = 100. B.B. becomes instantly white and
opaque and exfoliates, and then fuses to a globule, which
when placed upon moistened turmeric paper shows an alka-
line reaction. In a closed tube much water is given off.
Dissolves quietly in hydrochloric acid, and the solution gives
a heavy precipitate with barium chloride.
The principal varieties are as follows :
Selenite, including the transparent crystallized gypsum,
so called in allusion to its color and lustre from selene, the
Greek word for moon.
Radiated and Plumose gypsum, having a radiated struc-
ture.
Fibrous gypsum or satin S2)ar, white and delicately fibrous.
Snowy g ijp sum and Alabaster, including the white or light-
colored compact gypsum having a very fine grain.
Diff. The foliated gypsum resembles some varieties of
heulandite, stilbite, talc, and mica ; and the fibrous looks
like fibrous carbonate of lime, asbestus and some of the
fibrous zeolites ; but gypsum in all its varieties is readily
distinguished by its softness ; its becoming an opaque white
powder immediately and without fusion before the blow-
pipe, and by not effervescing or gelatinizing with acids.
Obs. Gypsum forms extensive beds in certain limestones
and clay beds, and also occurs in volcanic regions. New
York, near Lockport, affords beautiful selenite and snowy
- COMPOUNDS OP CALCIUM. 211
gypsum in limestone. At Camillas and Manlius, N. Y., and
in Davidson County, Term., are other localities. Fine crys-
tals of the form represented in figure 5 come from Poland
and Canfield, Ohio, and large groups of crystals from St.
Mary's in Maryland. Troy, N. Y., also affords crystals in
clay. In Mammoth Cave, Kentucky, alabaster occurs in
imitation of flowers, leaves, shrubbery, and vines. Alabas-
ter is obtained at Castelino in Italy, 35 miles from Leghorn.
Massive gypsum occurs abundantly in New York, from
Syracuse westward to the western extremity of Genesee
County, accompanying the rocks which afford the brine
springs ; also in New Brunswick, especially at Hillsboro',
where part is excellent alabaster; in Hants, Colchester, and
other districts in Nova Scotia; also in Ohio, Illinois, Vir-
ginia, Tennessee, Arkansas, and Nova Scotia; and in con-
nection with the Triassic beds of the Rocky Mountain
region; also abundant in Nevada and California. It is
abundant also in Europe.
Gypsum, when calcined, loses its water, becomes white,
is easily ground to a powder. This powder, when mixed
with a little water, takes up water again and becomes hard
and compact. This gypsum is plaster of Paris, and is used
for taking casts, making models, and forgiving a hard finish
to walls. Alabaster is cut into vases and various ornaments,
statues, etc. It owes its beauty for this purpose to its snowy
whiteness, translucency, and fine texture. Moreover, owing
to its softness, it can be cut or carved with common cutting
instruments. Gypsum is ground up and used for improving
soils.
Anhydrite. — Anhydrous Calcium Sulphate.
Trimetric. In rectangular and rhombic prisms, cleaving
easily in three directions, and readily breaking into square
blocks. /A/=100°30"*; 1UH=85° and
95°. Occurs also fibrous and lamellar, often
contorted ; also coarse and fine granular,
and compact.
Color white, or tinged with gray, red, or
blue. Lustre more or less pearly. Trans-
parent to subtranslucent. II. — 3-3*5. G.
= 2'<J-3.
Composition. Ca 04S = Sulphur trioxide
58 '8, lime 41-2 = 100. It is an anhydrous
calcium sulphate. B.B. and with acids,
DESCRIPTIONS OF MINERALS.
its reactions are like those of gypsum, except that in the
closed tube it gives no water.
A scaly massive variety containing a little silica has been
named Vulpinite; contorted concretionary kinds are some-
times called Tripestone. Anhydrite is called by miners hard"
plaster, because harder than gypsum.
I) iff. Its square forms of crystallization and cleavage are
good distinguishing characters. Its three easy cleavages, at
right angles with one another, look as if the crystalliza-
tion were cubic ; but there is some difference in the ease
with which they may be obtained.
Obs. A fine blue crystallized anhydrite occurs with gyp-
sum and calcareous spar in a black limestone at Lockport,
and near Windsor in Nova Scotia, and Hillsboro' in New
Brunswick. Foreign localities are at the salt mines of Bex
in Switzerland, Hall in the Tyrol, Ischl in Upper Austria,
Wieliczka in Poland, and elsewhere.
The vulpinite variety is sometimes cut and polished for
ornamental purposes.
Becliilite. A hydrous calcium borate occurring as an incrustation at
the Tuscan lagoons, Italy. A " hydrous borate of lime " reported by
Hayes from Iquique, Peru, has been called Hayesine ; but its com-
position has been questioned, it being referred to Ulexite. Howlite,
A hydrous calcium borate, containing silica ; Windsor, Nova Scotia.
Called also Silicoborocalcite.
Ulexite or Boronatrocalcite. A hydrous calcium-sodium borate, in
aggregations of fibres, from the dry plains of Iquique, Southern Peru;
Nova Scotia, at Windsor, Brookville, and Newport ; and Nevada, in
Columbus mining district, and at Thiel Salt Marsh, in Esmeralda
County.
OryptomorpMte. Another hydrous calcium-sodium borate ; Windsor,
Nova Scotia. Priceite is a calcium borate of white color and chalky
aspect, from Curry County, Oregon.
Hydrdboracite. A hydrous calcium-magnesium borate, resembling
gypsum in aspect.
Scheelite. Calcium tungstate, of pale yellowish-white color; H.=
4'5-5. G.=r5'9-6'l. From Monroe, Conn.; North Carolina ; Mammoth
mining district, Nevada ; Charity Mine, Idaho ; Golden Queen Mine,
Lake Co., Colorado; Seattle, Washington Territory; at Caldbeck
Fell, near Keswick, England ; in Bohemia, Hartz, Saxony, Hungary,
Sweden, Vosges. Cuproscheelite has part of the calcium replaced by
copper ; from La Paz, Lower California.
Apatite. — Calcium Phosphate.
Hexagonal. In hexagonal prisms. The annexed figure
represents a common form. Cleavage imperfect. Usually
occurs in crystals ; but occasionally massive ; sometimes
COMPOUNDS OP CALCIUM. 213
mammillary with a compact fibrous structure.
Small crystals are occasionally transparent
and colorless, but the usual color is green,
often yellowish green, bluish green, and gray-
ish green ; sometimes yellow, blue, reddish
or brownish. Coarse crystals nearly opaque.
Lustre vitreous to subresinous. H.=5. G.
= 3-3-25. Brittle. Some varieties phospho-
resce when heated, and some become electric
by friction.
Composition. Ca? 08 P2-J- J (C12, F2) = if without fluorine
Phosphorus pentoxide 40'92, lime 53 '80, chlorine 6 '82=100.
When chlorine is present in place of fluorine it is called
cMor-apatite, and when the reverse, fluor-apatite. B.B. in-
fusible except on the edges. Dissolves slowly in nitric acid
without effervescence. Its constituents are contained in
the bones and ligaments of animals, and the mineral has
probably been derived in many cases from animal fossils.*
Massive apatite is often called Phosphorite; and the pale
yellowish-green crystals, Asparagus stone. Osteolite is a
white earthy apatite. Eupyrchroite is a fibrous mammil-
lary variety from Crown Point, Essex County, N. Y.
fossil excrements, called coprolites, occur in stratified
rocks, and sometimes constitute extended beds ; and they
consist chiefly of calcium phosphate. Guano contains more
or less calcium phosphate along with hydrous phosphates
and some impurities.
Diff. Distinguished from beryl by its inferior hardness,
it being easily scratched with a knife ; from calcite by dis-
solving in acids without effervescence ; from pyromorphite
by its difficult fusibility, and giving no metallic reaction
before the blowpipe. Phosphoric acid may be detected by
moistening it with sulphuric acid and igniting it B.B.,
when it imparts a dirty green color to the flame.
Obs. Apatite occurs in gneiss, mica schist, hornblende
schist, granular limestone. In microscopic crystals it is
sparingly present in almost all crystalline rocks, the ig-
neous as well as metainorphic. The best crystals in the
United States occur in granular limestone ; the crystals
from the limestone of St. Lawrence County, N. Y., are
* Bones contain 25 per cent, of calcium phosphate, with some fluoride of calcium, 3
to 12 per cent, of calcium carbonate, some magnesium phosphate and sodium chloride,
besides 33 per cent, of animal matter.
214 DESCRIPTIONS OF MINERALS.
among the largest yet discovered in any part of the world;
one from Kobinson's farm measured a foot in length and
weighed 18 pounds; but they are nearly opaque and the
edges are usually rounded. They occur with scapolite,
sphene, etc. Edenville and Amity, Orange County, N. Y.,
afford fine crystals from half an inch to twelve inches
long. At Westmoreland, N. H., fine crystals are obtained
in a vein of feldspar and quartz ; also at Blue Hill Bay
in Maine. Bolton, Chesterfield, Chester, Mass., are other
localities. A beautiful blue variety is obtained at Dixon's
quarry, Wilmington, Delaware. Abundant in Burgess,
Elmsley, Grand Calumet Id., Hull, Buckingham, Port-
land, etc., in Canada.
The name apatite, from the Greek apatao, to deceive, was
given in allusion to the mistake of early mineralogists re-
specting the nature of some of its varieties.
Apatite, when abundant, is used like guano as a fertilizer,
on account of its phosphoric acid. To make it capable of
being taken up by plants it is treated first with a small por-
tion of sulphuric acid, which renders the phosphoric acid
soluble. When guano has been accumulated by birds, or
other animals, over coral rock, a calcium carbonate (as on
some coral islands), the waters in filtrating through it have
often carried down the soluble phosphoric acid or phosphates
into the underlying beds and turned them into calcium
phosphate.
Brushite and Metdbrushite. Hydrous calcium phosphates, found in
guano.
PyrophospJiorite. A white earthy phosphate from a guano deposit,
in the West Indies. Analysis gave it the composition of a pyrophos-
phate.
Pharmacolite and Raiding erite are hydrous calcium arsenates.
Nitrocalcite. Hydrous calcium nitrate. From caverns.
Pyrochlore. Occurs in small brown and brownish-yellow isometric
octahedrons. A calcium-cerium columbate. G.= 4 '3-4 '5. From Nor-
way, Siberia.
Microlite. In crystals similar in form to those of pyrochlore, but
in composition a calcium tantalate. G.=5'5-6. From Chesterfield,
Mass. , and Redding, Conn. Hatchettolite is a lime-uranium colum-
bate, from North Carolina.
Disanalyte. In cubes in granular limestone, a columbate and titan-
ate of calcium, cerium and iron. From the Kaiserstuhl.
Romeite and Atopite are calcium antimonates, the latter containing
also iron and soda.
COMPOUNDS OF CALCIUM.
215
Calcite. — Calc Spar. Calcium Carbonate.
Rhombohedral. R/\R (fig. 1) = 105°5'. Cleavage easy,
parallel with the faces of the fundamental rhombohedron.
1.
Calcite with the form in fig. 7 is often called dog-tooth
spar. Occurs fibrous with a silky lustre ; sometimes lamel-
lar ; often coarse or fine granular, and compact.
The purest crystals are transparent with a vitreous lustre ;
the impure massive varieties are often opaque, and without
lustre, and even earthy. The colors of the crystals are
either white or some light grayish, reddish or yellowish
tint, rarely deep red ; occasionally topaz-yellow, rose or
violet. The massive varieties are of various shades from
white to black, generally dull unless polished. H.=3.
G.=2-5-2-8.
Composition. Ca03C = Carbon dioxide 44, lime 56 = 100.
Sometimes impure from mixture with iron, silica, clay,
bitumen, and other substances. B.B. infusible; colors the
flame reddish, gives up its carbon dioxide, is thereby made
caustic, in which state it gives an alkaline reaction. Effer-
vesces in dilute cold hydrochloric acid. Many varieties
phosphoresce when heated.
The following are the principal varieties.
Iceland spar. Transparent crystalline calcite. first
brought from Iceland. Shows well double refraction.
Satin spar. A finely fibrous variety with a satin lustre.
Receives a handsome polish. Occurs usually in veins tra-
versing rocks of different kinds.
Chalk. White and earthy, without lustre, and so soft as
216 DESCRIPTIONS OP MINERALS.
to leave a trace on a board. Forms mountain beds. Most
chalk was made chiefly out of the shells of Rhizopods.
Rock milk. AVhite and earthy like chalk, but still softer,
and very fragile. It is deposited from waters containing
lime in solution. Rock meal is a powdery variety.
Calcareous tufa. Formed by deposition from waters like
rock milk, but more cellular or porous and not so soft.
Stalactite, Stalagmite. The name stalactite is explained
on page 60. The deposits of the same origin that cover
the floors of caverns are called stalagmite. They generally
consist of differently colored layers, and appear banded or
striped when broken. The so-called "Gibraltar rock" is
stalagmite from n cavern in the rock of Gibraltar.
Limestone is a general name for all the massive varieties
occurring in extensive beds.
Oolite, Pisolite. Oolite is a compact limestone, consist-
ing of small round concretionary grains, looking like the
spawn of a fish ; the name is derived from the Greek don,
an egg. Pisolite, a name derived from pisum, the Latin for
pea, differs from oolite in being coarser ; the spherules
often have a concentric structure, and thus show their con-
cretionary origin.
Argentine. A white shining limestone consisting of la-
minae a little waving, and containing some silica.
Fontainebleau limestone. This name is applied to crys-
tals of the form shown in figure 3, containing a large pro-
portion of sand, and occurring in groups. They were for-
merly obtained at Fontainebleau, France, but the locality
is exhausted.
Granular limestone. A limestone consisting of crystal-
line grains, and hence often called crystalline limestone.
The coarser varieties when polished constitute the common
white and clouded marbles, and are the material of which
" marble " buildings are made. The finer are used for
statuary, and are called statuary marble. The best is as
clear and fine-grained as loaf sugar, which it much re-
sembles.
Compact limestone. The limestones breaking with a
smooth surface, without a distinctly granular texture, and
dull in lustre unless polished. The rock is very variously
colored. The colors are sometimes arranged in blotches, or
veins. Kinds that are handsome when polished are used
as marbles. A black color is common, and is usually due to
COMPOUNDS OF CALCIUM. 21?
carbonaceous material of organic origin, and is proved by
the limestones becoming white when burnt.
Stinkstone, Antliraconife. A limestone which gives out
a fetid odor when struck. This odor is caused by certain
bituminous materials present in the rock.
Lithographic stone. A very compact fine-grained lime-
stone of a gray or grayish-yellow color.
Hydraulic limestone. An impure limestone. It contains
silica and alumina in such a condition that, when burned, it
will make a cement that hardens under water.
Diff. Distinguished by being scratched easily with a knife,
in connection with strongly effervescing in dilute acid,
and its complete infusibility. Calcite is not so hard as
aragonite, and possesses a very distinct cleavage, which
aragonite does not.
06s. Crystallized calc spar occurs in magnificent forms
in the vicinity of Rossie, New York. One crystal from
there, now in the Peabody Museum at New Haven, weighs
165 pounds. Some rose and purple varieties from this
region are very beautiful. Large geodes of the dog-tooth
spar variety occur in limestone at Lockport, along with
gypsum and pearl spar. Leyden and Lowville, N. Y., are
other localities. Bergen Hill, N. J., affords beautiful
wine-yellow crystals in amygdaloidal cavities ; also the
Lake Superior copper mines. Argentine occurs near
Williamsburg and Southampton, Mass. Rock milk covers
the sides of a cave at Watertown, JS". Y., and is now
forming Stalactites of great beauty occur in Weir's and
other caves in Virginia and in the Western States ; also in
Ball's Cave at Scoharie, N. Y. Chalk occurs in England
and Europe, and in Western Kansas in the United States.
Granular limestones are common in the Eastern and At-
lantic States, and compact limestones in the Middle and
Western States, and some beds of the former afford excellent
marble for building and some of good quality for stat-
uary.
Any of the varieties of this mineral when burnt form
quicklime, heat driving off the carbonic acid and leaving
the lime in a caustic state. In this state it is used for mak-
ing mortar by mixing with water and sand ; a calcium
hydrate results which becomes slowly carbonated through
carbonic acid in the atmosphere. See further the chapter
on Bocks, for the uses of limestone.
218
DESCRIPTIONS OF MINERALS.
Aragonite.
Trimetric. In rhombic prisms;*/ A 7=116° 10'. Cleavage
parallel with /. Usually in compound crystals having the
form of a hexagonal prism, with uneven or striated sides ;
or in stellated forms consisting of two or three flat crystals
crossing one another. Transverse sections of some of the
compound crystals are shown in figs. 1 to 4.
1.
3.
Occurs also in globular and coralloidal shapes ; also in
fibrous seams in different rocks.
Color white or with light tinges of gray, yellow, green and
violet. Lustre vitreous. Transparent to translucent. H.=
3-5-4. G. = 2'931.
Composition. Same as for calcite, and its action before
the blowpipe and with acids is the same, except that it falls
to powder readily when heated. Some varieties contain a
few per cent, of strontium carbonate, but this is not an
essential ingredient. Distinguished from calcite by the
absence of the cleavage of the latter, as well as the crystal-
line form ; also by its higher specific gravity.
Obs. Aragonite occurs mostly in gypsum beds and in
connection with iron ores ; also in basalt and other rocks.
The coralloidal forms are found in iron ore beds, and are
called Flos f err i, flowers of iron. They look like a loosely
intertwined or tangled white cord.
The fios-ferri variety occurs at Lockport with gypsum ;
also at Edenville, at the Parish iron ore bed in Rossie, and
in Chester County, Pennsylvania. Aragon in Spain affords
six-sided prisms of aragonite, associated with gypsum. This
locality gave the name to the species. Also found at Bilin,
in Bohemia, Tarnowitz in Silesia, and other places.
COMPOUNDS OF CALCIUM. 219
Dolomite. — Calcium-Magnesium Carbonate. Magnesian Carbonate of
Lime.
Rhombohedral. R A R= 106° 15'. Cleavage perfect pa-
rallel to R. Faces of rhombohedrons sometimes
curved, AS in the annexed figure. Often granular
and massive, constituting extensive beds.
Color white or tinged with yellow, red, green,
brown, and sometimes black. Lustre vitreous or
pearly. Nearly transparent to translucent. Brit-
tle. H.=3-5-4. G. =2 -8-2 -9.
Co?nposition. JCajMg 03 C — Calcium carbonate 54'35,
magnesium carbonate 45 '65 = 100. Some iron or manga-
nese is often present, replacing part of the magnesium or
calcium. Dolomite resembles calcite, but differs in that
unless finely pulverized it effervesces very sparingly, if at
all, in cold dilute hydrochloric acid.
The princpal varieties of this species arc as follows :
Dolomite. White, crystalline granular, often not distin-
guishable in external characters from granular limestone.
Pearl spar. In pearly rhombohedrons with curved faces.
Rhomb spar, Broivn spar. In rhombohedrons, which be-
come brown on exposure, owing to their containing 5 to 10
per cent, of oxide of iron or manganese.
A cobaltiferous variety has a red tint. A white compact
siliceous variety has been called Gurhqfite. Some hydraulic
limestones are dolomite.
Dijf. Distinctive characters nearly the same as for cal-
cite. It is harder than that species, and differs in the
angles of its crystals, and effervesces much less freely ; but
chemical analysis is often required to distinguish them.
Obs. Massive dolomite is common in Western New Eng-
land and Southeastern New York, and constitutes much
of the marble used for building. Crystallized specimens
are obtained at the Quarantine, Richmond County, N. Y.
Rhomb spar occurs in talc, at Smithfield, R. I. ; Marlboro',
Vt; Middlefield, Mass. ; pearl spar in crystals of the above
form at Lockport, Niagara Falls, Rochester, Glen's Falls ;
gurhofite on Hustis's farm, Phillipstown, N. Y.
Dolomite was named in honor of the geologist and trav-
eler, Dolomieu.
Dolomite burns to quicklime like calcite, and affords a
more durable cement. The white massive variety is used
220
DESCRIPTIONS OF MINERALS.
extensively as marble. The magnesian lime has been sup-
posed to injure soils ; but this is believed not to be the case
if it is air-slaked before being used. It is also employed in
the manufacture of Epsom salts or magnesium sulphate.
Ankerite. Resembles brown spar, and, like that, becomes brown on
exposure. Fundamental from a rhombohedron of 100° 12'. It is a
calcium-magnesium-iron-and-manganese carbonate. The Styrian iron
ore beds of Saltzburg are some of its foreign localities. It occurs in
Nova Scotia, and in quartz veins in Western New Hampshire ; Quebec,
Canada, etc.
Hydrodolomite. A calcium-magnesium carbonate containing water.
Pennite from Texas, Pa., is similar.
BARIUM AND STRONTIUM.
Barium and strontium occur in nature only in anhydrous
ternary compounds of the following kinds : sulphate, car-
bonate, silicate ; and in silicates only in combination with
other basic elements. The species are characterized by high
specific gravity, ranging from 3*5 to 4 -8. Strontium gives
a red color to the blowpipe flame ; and barium, if strontium
and other basic elements are absent, a characteristic green
color.
Barite. — Heavy Spar. Barium Sulphate.
Trimetric. In modified rhombic and rectangular prisms,
M/=101° 40'; 0Ap =141° 08' ; 0Al£=m° 18'. Crys-
tals usually tabular. Massive
varieties often coarse lamellar ;
also columnar, fibrous, granu-
lar and compact. Lustre vitr<
ous; sometimes pearly. Coloi
white and sometimes tingec
yellow, red, brown, blue, 01
dark brown. Transparent of
translucent. H.=2'5-3'5. Gr.
= 4-3-4-7.
Composition. Ba 04 S,
Sulphur tri oxide 34'3, baryta
G5'7=100. Strontium and cal-
cium are sometimes present re-
placing a little barium. B.B.
fuses to a bead which reacts
Imparts a green color to the flame. After fusion
1,
alkaline.
COMPOUNDS OF BARIUM AND STRONTIUM.
221
with soda in the reducing flame on coal, and then placed
on a silver coin and moistened, it produces a black stain,
due to sulphur.
Barite is often present in mineral veins as the gangue of
the ore. In this way it occurs at Cheshire, Conn. ; Hat-
field, Mass. ; Rossie and Hammond, New York ; Perkio-
men, Pennsylvania, and the lead mines of the Mississippi
Valley. Scoharie, and Pillar Point near Sackett's Harbor,
are other localities ; also near Fredericksburg and elsewhere,
Virginia ; Nova Scotia, etc. The variety from Pillar Point
receives a fine polish and looks like marble, the colors being
in bands or clouds.
Heavy spar is ground up and used to adulterate white
lead. When white lead is mixed in equal parts with it,
it is sometimes called Venice white, and another quality
with twice its weight of barite is called Hamburg white,
and another, one-third white lead, is called Dutch white.
When the material is very white, a proportion of it gives
greater opacity to the color, and protects the lead from
being speedily blackened by sulphurous vapors ; and these
mixtures are therefore preferred for certain kinds of painting.
Dreelite is a barium-calcium sulphate.
Witherite. — Barium Carbonate.
Trimetric. /A/— 118° 30'. Cleavage imperfect. Also
in globular -or botryoidal forms : often massive, and either
fibrous or granular. The mas-
sive varieties have usually a yellow-
ish or grayish-white color, with a
lustre a little resinous, and are
translucent. The crystals are often
white and nearly transparent. H.
=3-4. G.=:4-29-4-35. Brittle.
Composition. Ba 03 C = Carbon
dioxide 22-3, baryta 77 '7 = 100. B.
B. decrepitates and fuses easily,
tingeing the flame green, to a trans-
lucent globule, which becomes
opaque on cooling, and colors a
moistened turmeric paper red.
r Effervesces in hydrochloric acid.
, ^ Diff. Distinguished by its spe-
cific gravity and fusibility from calcite and aragonite; its
DESCRIPTIONS OP MINERALS.
action with acids, from allied minerals that are not carbon-
ates ; by yielding no metal, from cerussite, and by tingeing
the flame green, from strontianite.
Obs. The most important foreign localities of witherite
are at Fallowfield in Northumberland (where it is mined).
Alstonmoor in Cumberland, and Anglezark in Lancashire.
It is also found in Silesia, Styria, and Sicily. In the United
States it occurs at Lexington, Ky.
Witherite-, from Fallowfield, is used in chemical works, in
the manufacture of plate glass, and in France in the manu-
facture of beet sugar.
Barytocalcite, Occurs at Alstonmoor in Cumberland, England, in
•whitish monoclinic crystals. H.=4 G. =3 6-3 '7. It is a barium-
calcium carbonate.
Bromlite is a trimetric mineral, of the same composition, from
Bromley Hill, near Alston, and from Northumberland, England.
Celestite. — Strontium Sulphate.
Trimetric. /A/=103° 30' to 104° 30'. Crystals rhombic
prisms or tabular ; often long and slender. Cleavage dis-
tinct parallel with /. Mas-
sive varieties : columnar or
fibrous, forming layers half
an inch or more thick with
a pearly lustre ; rarely gran-
ular. Color -generally a
tinge of blue, but sometimes
clear white or reddish. Lus-
tr^ vitreous or a little pearly ; transparent to translucent.
R. = 3-3-5. G. =3-9-4. Very brittle.
Composition. Sr 04S=Sulphur trioxide 43'6, strontia
56 '4:= 100. B.B. decrepitates and fuses, tinging the flame
bright red to a milk-white alkaline globule, which gives
an alkaline reaction. With soda on coal fuses to a mass
which when moistened blackens silver.
Diff. From barite, which it resembles, it is distinguished
by the bright red color it imparts to the blowpipe flame, and
its less specific gravity ; and from the carbonates, by not ef-
fervescing with acids.
Obs. Celestite is found in beds of sandstone or lime-
stone, and also with gypsum, rock salt, and clay. A bluish
celestine, in tabular and prismatic crystals, occurs at Stron-
tian Island, Lake Erie ; Scoharie, Lockport and Kossie,
COMPOTTKDS OF TCTASSIUM AKD SODIUM. #23
Y., are*other localities. A handsome fibrous variety occurs
at Franktown, Huntingdon County, Pennsylvania. Sicily
affords fine crystallizations associated with sulphur.
The pale sky-blue tint, so common with the mineral, gave
origin to the name celestite.
Celestite is used in the arts for making the nitrate of
strontia, which is employed for producing a red color in fire-
works.
Strontianite . — Strontium Carbonate.
Trimetric. /A/=117° 19'. Cleavage parallel to/, near-
ly perfect. Occurs also fibrous and granular, and sometimes
in globular shapes with a radiated structure within.
• Color often a light tinge of green ; also white, gray, and
yellowish brown. Lustre vitreous, or somewhat resinous.
Transparent to translucent. H. = 3-5-4. G. =3-6-3 '72.
Brittle.
Composition. Sr 03 C = Carbon dioxide 29 '7, strontia
7O3— 100. A small part of the strontium is often replaced
by calcium. 13. B. swells, throws out little sprouts, but
does not fuse. Colors the flame bright red, and after heat-
ing possesses an alkaline reaction. Effervesces in cold di-
lute acid ; sulphuric acid gives a precipitate of strontium
sulphate.
Diff. Its effervescence with acids distinguishes it from
minerals that are not carbonates ; the color of the flame
before the blowpipe, from witherite and all other carbon-
ates ; calcium salts also give a red color to the flame, but
the shade is yellowish, and less brilliant.
Obs. Strontianite occurs in limestone at Scoharie, N". Y.,
in crystals, and also fibrous and massive ; and in Jeffer-
son County, N. Y., and Mifflin County, Penn. Strontian
in Argyleshire, England, was the first locality known, and
gave the name to the mineral and the metal strontium. It
occurs there, with galenite, in stellated and fibrous groups
and in crystals.
This mineral is used for preparing the strontium nitrate.
POTASSIUM AND SODIUM.
Potassium and sodium occur in nature in the state of
chloride, sulphate, nitrate, and carbonate, and are constitu-
ents in many silicates.
224 DESCRIPTIONS OF MINERALS.
Sylvite. — Potassium Chloride.
Isometric. White or colorless, with vitreous lustre, and
taste nearly that of common salt. The crystals are often
cubes with octahedral planes, like fig. 8 on p. 19. II. —2.
G.= 1-9-2.
Composition. K 01= Chlorine 47'5, potassium 52 '5 = 100.
From Vesuvius, about the f umaroles of the volcano.
Halite.— Common Salt. Sodium Chloride.
Isometric. In cubes and other related forms. Some-
times crystals have the shape of a shallow four-sided cup,
and are called hopper-shaped crystals ; they were formed
floating, the cup receiving its enlargement at the margin,
this being the part which lay at the surface of the brine
where evaporation was going on. Cleavage cubic, perfect.
Color usually white or grayish, sometimes rose-red, yel-
low, and of amethystine tints. Taste saline. II. =2. G.=
2-257.
Composition. Na Cl= Chlorine 60'7, sodium 39'3 = 100.
Crackles or decrepitates when heated ; fuses easily, coloring
the flame deep yellow.
Diff. Distinguished by its taste, solubility, and blowpipe
characters.
Obs. Salt occurs in extensive but irregular beds, usually
associated with gypsum, anhydrite, and clays or sandstone.
It occurs in formations of .all ages, from the Silurian to the
present time. It exists in the Pyrenees, in the valley of
Cardona and elsewhere, forming hills 300 to 400 feet high ;
in Poland and Wieliczka ; at Hall in the Tyrol, and along a
range through Reichcnthal in Bavaria, Halleinin Saltzburg,
Hallstadt, Ischl and Ebensee in Upper Austria, and Aussee
in Styria ; in Hungary at Marmoros and elsewhere ; in
Transylvania, Wallachia, Galicia and Upper Silesia ; at
Vic and Dieuze in France ; at Bex in Switzerland ; in
Cheshire, England ; in Northern Africa in vast quantities
forming hills and extended plains ; in Northern Persia at
Tiflis ; in India in the province of Lahore, and in the valley
of Cashmere ; in China and Asiatic Russia; in South Amer-
ica, in Peru and the Cordilleras of New Granada.
Among the most remarkable deposits are those of Poland
and Hungary. The former, near Cracow, have been worked
since the year 1251, and it is calculated that there is still
COMPOUNDS OF POTASSIUM AND SODIUM. 225
enough salt remaining to supply the whole world for many
centuries. Its deep subterranean regions are excavated into
houses, chapels and other ornamental forms, the roof being
supported by pillars of salt ; and when illuminated by lamps
and torches, they are objects of great splendor.
The salt is often impure with clay, and is purified by dis-
solving it in large chambers, drawing it off after it has
settled, and evaporating it again. The salt of Norwich (in
Cheshire) is in masses 5 to 8 feet in diameter, which are
nearly pure, and it is prepared for use by crushing it be-
tween rollers.
In North America, beds of rock salt exist at Goderich in
Canada ; at Wyoming in Western New York (reached by
boring to a depth of 1,279 feet) ; in Washington County, in
Virginia; and extensively at Petite Anse in Louisiana, where
it underlies 144 acres ; in Nevada, at several localities ; in
Ihe Salmon River Mountains, Oregon.
Brine springs also proceed from rocks of various ages;
and often they are indications of deep-seated beds of rock
salt.
The salt of Western New York, and Goderich, Canada,
is of the Salina period of the Upper Silurian ; the brine
springs of Michigan, from shales and marly tes of the Sub-
carboniferous period ; those of the salt beds of Norwich,
England, in magnesian limestone of the Permian ; those of
the Vosges and of Saltzburg, Ischl, and the neighboring
regions, in marly sandstone of the Triassic ; those of Bex,
in Switzerland, in the Lias formation; that of Wieliczka,
Poland, and the Pyrenees, in the Cretaceous or chalk forma-
tion; that of Catalonia, in the Tertiary ; that of Louisiana,
in the Quaternary, and large deposits are still more recent ;
and besides there are lakes that are now evaporating and
Producing salt depositions.
Vast lakes of salt water exist in many parts of the world.
The Great Salt Lake of Utah has an area of 2,000 square
miles, and is remarkable for its extent, considering that it
is situated toward the summit of the Rocky Mountains, at
an elevation of 4,200 feet above the sea. Its waters contain
^<) per cent, of sodium chloride (common salt). The dry
regions of these mountains and of Southwestern California
are noted for salt licks and lakes. In Northern Africa
large lakes as well as hills of salt abound, and the deserts
of this region and Arabia abound in saline efflorescences.
226 DESCRIPTIONS OF MINERALS.
The Dead and Caspian Seas, and the lakes of Khoordistan,
are salt. From 20-26 per cent, of the weight of the water
from the Dead Sea are solid salts, of which 10 per cent, are
common salt Over the pampas of La Plata and Patagonia
there are many ponds and lakes of salt water.
The greater part of the salt made in this country is ob-
tained by evaporation from salt springs. Those of Salina and
Syracuse are well known ; and many nearly as valuable are
worked in Ohio and other Western States. At the best New
York springs a bushel of salt is obtained from every 40 gal-
lons. But the discovery of rock salt at Wyoming, west of
Syracuse, may lead to further discoveries, which will make
the brines of New York of comparatively little value. To
obtain the brine, wells from 50 to 150 feet deep are sunk by
boring. It is then raised by machinery.
The process of evaporation under the heat of the sun is
extensively employed in hot climates for making salt from
sea water, which affords a bushel for every 300 or 350 gal-
lons. For this purpose a number of large shallow basins
are made adjoining the sea ; they have a smooth bottom of
clay, and all communicate with one another. The water is
let in at high tide and then shut off for the evaporation to
go on. This is the simplest mode, and is used even in un-
civilized countries, as among the Pacific Islands.
Mirabilite.— Glauber Salt. Hydrous Sodium Sulphate.
Monoclinic. Occurs in efflorescent crusts of a white or
yellowish-white color ; also in many mineral waters. Taste
cool, then feebly saline and bitter.
Composition. Na2 04 S 4- lOaq = Sulphur trioxide 24 '8,
soda 19-3, water 55-9 = 100.
Diff. It is distinguished from Epsom salt, for which it
is sometimes mistaken, by its coarse crystals, and the yel-
low color it gives to the blowpipe flame.
It is made in enormous amounts from common salt, its
production being one stage in the manufacture of sodium
carbonate. It is used in medicine, and is known by the
familiar name of " salts."
Obs. On Hawaii, one of the Sandwich Islands, in a cave
at Kailua, Glauber salt is abundant, and is constantly form-
ing. It is obtained by the natives and used as medicine.
Glauber salt occurs in efflorescences on the limestone below
COMPOUNDS OP POTASSIUM AND SODIUM. 227
Genesee Falls, near Rochester, N.Y. It is also obtained in
Austria, Hungary, and elsewhere in Europe.
The artificial salt was first discovered by a German
chemist by the name of Glauber.
AphtMtalite (Arcanite). Potassium sulphate, K204S= Sulphate trL
oxide 45'9, potash 54* 1=100. Found at Vesuvius. Misenite is a hy-
drous potassium sulphate from a cavern near Misene.
Thenardite. Sodium sulphate N a, 04S= Sulphur trioxide 437,
soda 56-3=100. From Spain, Bolivia, Tarapaca, in Peru; Slate Range,
San Bernardino Co. , California ; and in Nevada.
Glauberite. Sodium-calcium sulphate. In monoclinic crystals, at
Villa Rubia, in New Castile, Aussee, in Austria, and other salt beds.
Poli/halite and Picromeride are hydrous magnesium-potassium sul-
phates ; Blazdite and Loweite hydrous magnesium-sodium sulphates ;
Syngenite, a hydrous calcium-potassium sulphate.
Borax. — Hydrous Sodium Biborate. Tinkal.
Monoclinic. In oblique rhombic prisms /A 7=87°. Cleav-
age parallel with i-i perfect. The crystals are white and
transparent, with a glassy lustre. H. =2-2 '5. G. =1*716.
Taste sweetish-alkaline.
Composition. Na207B44-10aq= Boron trioxide 36-6, soda
16-2, water 47*2 = 100. B.B. swells up to many times its
bulk and becomes opaque white, and finally fuses to a
glassy globule.
01)S. Borax was originally brought from a salt lake in
Thibet, where it is dug in considerable masses from the
edges and shallow parts of the lakes. The holes thus made
in a short time become filled again with borax. The crude
borax was formerly sent to Europe under the name of tin-
leal, and there purified for the arts. It has also been found
in Peru and Ceylon. It has been extensively made from the
boracic acid of the Tuscan lagoons by the reaction of this
acid on sodium carbonate.
Borax occurs under like circumstances in California and
Nevada, or is manufactured from other borates in solution
or in the solid state. Localities in California are Borax
Lake and its vicinity, north of San Francisco ; also near
Walker's Pass, Sierra Nevada; at Mono and Owens Lakes,
and at Death Valley, near the borders of Nevada ; in
the Slate Range, in San Bernardino County ; and in
Nevada, at Little Salt Lake, near Ragtown, on the Pacific
Railroad, and at Columbus Marsh. The Columbus Marsh,
in Nevada, near lat. 38° 5' N. and long. 118° W., 46 miles
228 DESCRIPTIONS OF MINERALS.
north of trail from Mono Lake, is a deposit, 10 miles long
by 7 wide, of borates and other salts, chiefly borax, calcium
borate, sodium sulphate, and common salt. The large de-
posits of " priceite" in Southern Oregon, and of ulexite, in
the " Cane Spring District," 20 miles west of San Bernar-
dino, and at the Columbus Marsh, are other sources of
borax. The amount of borax received at San Francisco
during the year 1876 was 5,180,910 pounds, and in 1877,
4,154,209 pounds.
Nitre. — Potassium Nitrate.
Trimetric. In modified right rhombic prisms. / : 1=
118° 50'. Usually in thin white sub transparent crusts, and
in needleform crystals on old walls and in caverns. Taste
saline and cooling. H = 2. G=1'97.
Composition. K803N= Nitrogen pentoxide (N2 05) 53 '4,
potash 46 '6. Burns vividly on a live coal.
Diff. Distinguished readily by its taste and its vivid ac-
tion on a live coal ; and from sodium nitrate, which it most
resembles, by its not becoming liquid on exposure to the
air.
Nitre, called also saltpetre, is employed in making gun-
powder, forming 75 to 78 per cent, in shooting powder, and
62 in mining powder. The other materials are sulphur (10
per cent, for shooting powder to 20 for mining) and char-
coal (12 to 14 for shooting powder and 18 for mining). It
is also extensively used in the manufacture of nitric and
sulphuric acids ; also for pyrotechnic purposes, fulminating
po\vders, and sparingly in medicine.
Obs. Occurs in many of the caverns of Kentucky and
other Western States, scattered through the earth that
forms the floor of the cave. In procuring it, the earth is
lixiviated, and the lye, when evaporated, yields the nitre.
India is its most abundant locality, where it is obtained
largely for exportation.
Spain and Egypt also afford large quantities of nitre for
commerce. This salt forms on the ground in the hot weather
succeeding copious rains, and appears in silky tufts or efflo-
rescences ; these are brushed up by a kind of broom, lixi-
viated, and after settling, evaporated and crystallized. In
France, Germany, Sweden, Hungary, and other countries,
there are artificial arrangements called nitriaries or nitre
beds, from which nitre is obtained by the decomposition
COMPOUNDS OF POTASSIUM AND SODIUM. £29
mostly of the nitrates of lime and magnesia which form in
these beds. Refuse animal and vegetable matter putrefied
in contact with calcareous soils produces nitrate of lime,
which affords the nitre by reaction with carbonate of pot-
ash. Old plaster lixiviated affords about 5 per cent. This
last method is much used in France. The nitric acid of
the cavern nitrates comes from the atmosphere, which also
consists of nitrogen and oxygen ; but the combination takes
place through the agency of a peculiar kind of microscopic
plant.
Nitratine.— Soda Nitre. Sodium Nitrate. Cubic Nitre.
Rhombohedral ; R : R= 106° 33'. Also in crusts or efflo-
rescences, of white, grayish and brownish colors. Taste
cooling. Soluble and very deliquescent.
Composition. Ha* 03N= Nitrogen pentoxide 63-5, soda
36'5 — 100. Burns vividly on coal, with a yellow light.
Diff. It resembles nitre (saltpetre), but deliquesces, and
gives a deep yellow light when burning.
Obs. In the district of Tarapaca, Northern Chili, the
dry Pampa for an extent of forty leagues is covered with
heds of this salt, mixed with gypsum, common salt, glauber
salt, and remains of recent shells.
It is used extensively in the manufacture of nitric acid.
It is also used in making nitre by replacing the sodium by
potassium. In 1866, one million quintals of this salt were
exported from Chili.
Natron. — Hydrous Sodium Carbonate. Carbonate of Soda.
Monoclinic. Generally in white efflorescent crusts, some-
times yellowish or grayish. Taste alkaline. Effloresces on
exposure, and the surface becomes white and pulverulent.
Composition. Na203 C 4-1 Oaq = Carbon dioxide 26 '7, soda
1S'8, water 54*5 = 100. Effervesces strongly with acids.
* Diff. Distinguished from other soda salts by efferves-
cing, and from trona, by efflorescing on exposure.
Obs. This salt is found in solution in certain waters,
from which it is crystallized in efflorescences by evapora-
tion. Abundant in the soda lakes of Egypt ; also in lakes
at Debreezin, in Hungary ; in Mexico, north of Zacatecas,
and elsewhere. Sparingly dissolved in the Seltzer and
Carlsbad waters.
230 DESCRIPTIONS OF MINERALS.
This salt (but the artificially prepared) is extensively
used in the manufacture of soap and glass, and for many
other purposes.
Trona. A hydrous sodium sesquicarbonate occurs in the province
of Suckenna, in Africa, between Tripoli and Fezzan, where it forms a
fibrous layer an inch thick beneath the soil. It is abundant at a lake
in Maracaibo, 48 miles from Mendoza ; and forms an extensive bed in
Churchill County, Nevada.
Thermonatrite. A hydrous sodium carbonate of the formula Naa
O3C+aq. An anhydrous sodium carbonate is stated to exist native.
Gay-Lus&ite. Occurs in white brittle monoclinic crystals. Com-
position ^Na|CaO3C+2iaq. From Lagunilla, in Maracaibo, and Lit-
tle Salt Lake, near Ragtown, in Nevada.
AMMONIUM.
The salts of ammonia are more or less soluble in water,
and are entirely and easily volatilized before the blowpipe.
When treated with caustic lime or potassa, ammonia is lib-
erated, and is recognized by its odor and the reaction of the
vapors on test papers.
Salmiak, — Sal Ammoniac, Ammonium Chloride.
Occurs in white crusts or efflorescences, often yellowish
or gray. Crystallizes in regular octahedrons. Translucent
— opaque. Taste saline and pungent. Soluble in three parts
of water.
Composition. NH4 01= Chlorine 66'3, ammonium 33*7=
100. Gives oil the odor of ammonia when powdered and
mixed with quicklime.
Obs. Occurs in many volcanic regions, as at Etna, Vesu-
vius, and the Sandwich Islands, where it is a product of
volcanic action. Occasionally found about ignited coal
seams.
The sal ammoniac of commerce is manufactured from
animal matter or coal soot. It is generally formed in chim-
neys of both wood and coal fires. In Egypt, whence the
greater part of this salt was formerly obtained, the fires of
the peasantry are made of the dung of camels ; and the soot
which contains a considerable portion of the ammoniacal
salt is preserved and carried in bags to the works, where it
is obtained by sublimation. Bones and other animal mat-
ters are used in Erance. A liquid condensed in the gas
works, is also used in its production.
WATER. 231
It is a valuable article in medicine, and is employed by
tinmen in soldering to prevent the oxidation of copper sur-
faces ; also in a variety of metallurgical operations.
Mascagnite. A hydrous ammonium sulphate. In mealy crusts,
of a yellowish-gray or lemon-yellow color ; translucent ; taste pungent
and bitter. Composition (N H4)2O4 S + H.,0 = Sulphur trioxide 53'3,
ammonia 22 '8, water 23 '9. Easily soluble in water. Occurs at Etna,
Vesuvius, and the Lipari Islands. It is one of the products from the
combustion of anthracite coal.
Lecontite is hydrous ammonium-sodium sulphate. Boussingaultite
is a hydrous ammonium-magnesium sulphate, from Tuscany.
Struvite. A hydrous ammonium-magnesium phosphate ; occurring
in yellowish crystals, slightly soluble in water ; found on the site
of an old church in Hamburg, where there had been quantities of cat-
tle dung.
Tschermigite. An ammonia alum from Tschermig, Bohemia, and
Utah County, Utah
Larderellite. A white tasteless ammonium borate, from the Tuscan
lagoons.
Hydrous ammonium phosphate and Ammonium bicarbonate (Tcsche-
macherite) have been detected in guano ; also, Hydrous sodium-am-
monium phosphate, called Stercorite.
HYDROGEN.
Hydrogen is the basic constituent in hydrochloric acid,
and in water.
Hydrochloric Acid. — Muriatic Acid.
A gas, consisting of Chlorine 97'26, hydrogen 2-74=100
= H 01. It has a pungent odor, and is acrid to the skin.
It is rapidly dissolved by water. If passed into a solution
of nitrate of silver, it produces a white precipitate which
soon blackens on exposure. It is given out whenever com-
mon salt is acted on by sulphuric acid, and occasionally by
volcanoes.
WATER.
Water (hydrogen oxide) is the well-known liquid of
streams and wells. The purest natural water is obtained by
melting snow, or receiving rain in a clean glass vessel ; but it
is absolutely pure only when procured by distillation. It
consists of hydrogen 1 part by weight, and oxygen 8 parts,
or hydrogen ll'll, oxygen 88'89 = i'00. It becomes solid at
.32° Fahrenheit (or 6° Centigrade), and then crystallizes,
and constitutes ice or snow. The crystals are of the hex-
agonal system. Flakes of snow consist of a congeries of
232 DESCRIPTIONS OP MINERALS.
minute crystals, and stars, like the figures on page 4, may
often be detected with a glass. Various other allied forms
are also assumed. The rays meet at an angle of 60°, and
the branchlets pass off at the same angle with perfect regu-
larity. The density of water is greatest at 39° 2' F.; below
this it expands as it approaches 32°, owing to incipient
crystallization, and in the state of ice it is only 0-920. It
boils at 212° F. A cubic inch of pure water at 62° F. and 30
inches of the barometer, weighs 252*458 grains, which equals
16'386 grams; and a cubic foot of water weighs 62-355
pounds avoirdupois. A pint, United States standard mea-
sure, holds just 7,342 troy grains of water, which is little
above a pound avoirdupois (7,000 grains troy).
Water, as it occurs on the earth, contains some atmo-
spheric air, without which the best would be unpalatable.
This air, with some free oxygen also present, is necessary
to the life of aquatic animals. In most spring water there
is a minute proportion of salts of calcium (sulphate, chloride
or carbonate), often with a trace of common salt, carbonate
of magnesium and some alumina, iron, silica, phosphoric acid,
carbonic acid, and certain vegetable acids. These impuri-
ties constitute usually from -fa to 10 parts, in 10,000 parts
by weight. The water of Long Pond, near Boston, con-
tains about £ a part in 10,000 ; the Schuylkill of Philadel-
phia, about 1 part in 10,000 ; the Croton, used in New York
city, 1 to 1^ parts in 10,000. Nitric acid is usually found
in rain water combined with ammonia ; river waters are
ordinarily the purest of natural waters, unless they have
flowed through a densely populated region.
Sea water contains from 32 to 37 parts of solid substances
in solution in 1,000 parts of water. The largest amount in
the Atlantic, 36*6 parts, is found under the equator, away
from the land or the vicinity of fresh-water streams ; and
the smallest in narrow straits, as Dover Straits, where there
are only 32-5 parts. In the Baltic and Black Seas, the pro-
portion is only one-third that in the open ocean. Of the
whole, one-half to two-thirds is common salt (sodium chlo-
ride). The other ingredients are magnesium salts (chloride
and sulphate), amounting to four-fifths of the remainder,
with sulphate and carbonate of calcium, and traces of bro-
mides, iodides, phosphates, borates and fluorides. The water
of the British Channel affords water 964'7 parts in 1,000,
sodium chloride 27*1, potassium chloride 0'8, magnesium
SILICA. 233
chloride 3 '7, magnesium sulphate 2*30, calcium sulphate
1-4, calcium carbonate 0-03, with some magnesium bromide
and probably traces of iodides, fluorides, phosphates and
borates. The bitter taste of sea water is owing to the salts
of magnesium present.
The waters of the Dead Sea contain 200 to 260 parts of
solid matter in 1,000 parts (or 20 to 26 per cent), including
7 to 10 per cent, of common salt, the same proportion of
magnesian salts, principally the chloride, 2£ to 3£ per cent,
of calcium carbonate and sulphate, besides some bromides
and alumina. The density of these waters is owing to this
large proportion of saline ingredients. The brine springs
of New York and other States south and west, are well-
known sources of salt (see under Common salt). Many of
the springs afford bromine, and large quantities of it are
manufactured for making photographic plates and for other
purposes.
Mineral waters vary much in constitution. They often
contain iron in the state of bicarbonate, like those of Sara-
toga and Ballstown, and are then called chalybeate waters,
from the ancient name for iron or steel, clialybs, derived
from the name of a country on the Baltic. Hydrogen sul-
phide is often held in mineral waters and imparts to them
its odor and taste ; such are the so-called sulphur springs.
Minute traces of salts of zinc, arsenic, lead, copper, an-
timony and tin, have been found in some waters. What-
ever is soluble in a region through which waters flow, will
of course be taken up by them, and many ingredients are
soluble in minute proportions, which are usually described
as insoluble.
III. SILICA AND SILICATES.
I. SILICA.
Quartz.
Rhombohedral. Occurs usually in six-sided prisms, more
or less modified, terminated with six-sided pyramids : R/\R
=94° 15'. No cleavage apparent, seldom even in traces ;
but sometimes obtained by heating the crystal and plunging
it into cold water. Sometimes in coarse radiated forms;
234
DESCRIPTIONS OF MINERALS.
also coarse and fine granular ; also compact, either amor-
phous, or presenting stalactitic and rnammillary shapes.
Crystals often as pellucid as glass, and colorless ; some-
times topaz-yellow, amethystine, rose, smoky, or other tints.
Also of all degrees of transparency to opaque, and of various
shades of yellow, red, green, blue and brown colors to black.
In some varieties the colors are in bands, stripes, or clouds,
1.
2.
5.
Composition. Si02=0xygen 53'33, silicon 46-67 = 100.
Opaque varieties often contain oxide of iron, clay, chlorite,
or some other mineral disseminated through them. B.B.
infusible. With soda, fuses with effervescence.
Diff. Quartz is exceedingly various in color and form,
but may be distinguished, by (1) absence of true cleavage;
(2) its hardness ; (3) its infusibility before the blowpipe ;
(4) its insolubility with either of the common acids; (5) its
effervescence when heated B.B. with soda ; and (6) when
crystallized, by the forms of its crystals, which are almost
always six-sided prisms terminating in six-sided pyramids.
The varieties of quartz owe their peculiarities either to
crystallization, mode of formation, or impurities, and they
fall naturally into three series.
I. The vitreous varieties) distinguished by their glassy
fracture.
II. The clialcedonic varieties, having a subvitreous or a
waxy lustre, and generally translucent.
III. Thejaspery cryptocrystalline varieties, having barely
a glimmering lustre or none, and opaque.
I. VITREOUS VARIETIES.
Rock Crystal. Pure pellucid quartz.
This is the mineral to which the word crystal was first
applied by the ancients ; it is derived from the Greek krus-
tallos, meaning ice. The pure specimens are often cut and
used in jewelry, under the name of '•' white stone."
It is often used for optical instruments and spectacle
SILICA. 235
glasses, and even in ancient times was made into cups and
vases. Nero is said to have dashed to pieces two caps of
this kind on hearing of the revolt that caused his ruin, one
of which cost him a sum equal to $3,000.
Amethyst. Purple or bluish-violet, and often of great
beauty. The color is owing to a trace of manganese oxide.
It was called amethyst on account of its supposed preser-
vative powers against intoxication. When finely and uni-
formly colored, highly esteemed as a gem.
Rose Quartz. Pink or rose-colored. Seldom occurs in
crystals, but generally in masses much fractured, and im-
perfectly transparent. The color fades on exposure to the
light, and on this account it is little used as an ornamental
stone, yet is sometimes cut into cups and vases.
False Topaz. Light yellow pellucid crystals. They are
often cut and set for topaz. The absence of cleavage dis-
tinguishes it from true topaz. The name citrine, often ap-
plied to this variety, alludes to its yellow color.
Smoky Quartz. Crystals of a smoky tint ; the color is
sometimes so dark as to be nearly black and opaque except
in splinters. It is the cairngorm stone.
Milky Quartz. Milk-white, nearly opaque, massive, and
of common occurrence. It has often a greasy lustre, and is
then called greasy quartz.
Prase. Leek-green, massive ; resembling some shades of
beryl in tint, but easily distinguished by the absence of
cleavage and its infusibility. Supposed to be colored by a
trace of iron silicate.
Aventurine Quartz. Common quartz spangled through-
out with scales of golden-yellow mica. It is usually trans-
lucent, and gray, brown, or reddish brown in color.
Ferruginous Quartz. Opaque, and either of yellow,
brownish-yellow, or red color. The color is due to the
presence of iron oxide as an impurity, the red to the anhy-
drous oxide, and the brownish yellow to the hydrous oxide.
H. CHALCEDONIC VARIETIES.
Chalcedony. Translucent, massive, with a glistening and
somewhat waxy lustre ; usually of a pale grayish, bluish, or
light brownish shade. Often occurs lining or filling cavities
in amygdaloidal rocks, and sometimes in other kinds. These
cavities are nothing but little caverns, into which siliceous
waters have filtrated at some period. The stalactites are
236 DESCRIPTIONS OP MINERALS.
"icicles" of chalcedony, hung from the roof of the cavity.
Some of these chalcedony grottos are several feet in dia-
meter. Large geodes of this kind occur in the Keokuk
limestone in Illinois and Iowa.
Chrysoprase. Apple-green chalcedony. It is colored by
nickel.
Carnelian. A bright red chalcedony, generally of a clear
rich tint. It is cut and polished and much used in the more
common jewelry. It is often cut for seals and beads.
Sard. A deep brownish-red chalcedony, of a blood-red
color by transmitted light.
Agate. A variegated chalcedony. The colors are dis-
tributed in clouds, spots, or concentric lines. These lines
take straight, circular, or zigzag forms ; and when the last
it is called fortification agate, so named from the resem-
blance to the angular outlines of a fortification. These lines
are the edges of la}rers of chalcedony, and these layers are
the successive deposits during the process of its formation.
Mocha stone or Moss agate is a brownish agate, consisting
of chalcedony with dendritic or moss-like delineations, of an
opaque yellowish-brown color. They arise from dissem-
inated iron oxide. All the varieties of agate are beautiful
stones when polished, but are not much used in fine jewelry.
The colors may be darkened by boiling the stone in oil, and
then dropping it into sulphuric acid ; a little oil is absorbed
by some of the layers, which becomes blackened or charred
by the acid.
Onyx. A kind of agate having the colors arranged in
flat horizontal layers ; the colors are usually light clear
brown and an opaque white. When the stone consists of
sard and white chalcedony in alternate layers, it is called
sardonyx. Onyx is the material used for cameos, and is
well fitted for this kind of miniature sculpture. The figure
is carved out of one layer and stands in relief on another.
A noted ancient cameo is the Mantuan vase at Brunswick.
It was cut from a single stone, and has the form of a cream-
pot, about 7 inches high and 2£ broad. On its outside,
which is of a brown color, there are white and yellow groups
of raised figures, representing Ceres and Triptolemus in
search of Proserpine.
Cat's Eije is greenish-gray translucent chalcedony, hav-
ing a peculiar opalescence, or glaring internal reflections,
like the eye of a cat, when cut with a spheroidal surface.
SILICA. 237
1'he effect is owing to filaments of asbestus. It comes from
Ceylon and Malabar, ready cut and polished, and is a gem
of considerable value.
Flint, Hornstone. Massive compact silica, of dark shades
of smoky gray, brown, or even black, and feebly translucent,
it breaking with sharp cutting edges and a conchoidal sur-
face. Flint occurs in nodules of chalk: notunfrequently the
nodules are in part chalcedonic. Hornstone differs from
flint in being more brittle ; it is often found in limestone.
Chert is an impure hornstone. Limestones containing
hornstone or chert are often called clierty limestone.
Plasma. A faintly translucent variety of chalcedony ap-
proaching jasper, of a green color, sprinkled with yellow
and whitish dots.
III. JASPERY VARIETIES.
Jasper. A dull red or yellow siliceous rock, containing
some clay and yellow or red iron oxide, the red, the anhy«
drous oxide, ami the yellow, the hydrous oxide. Heat drives
off the water from the yellow jasper and turns it red. It
also occurs of green and other shades. Riband jasper is a
jasper consisting of broad stripes of green, yellow, gray,
red, or brown. Egyptian jasper consists of these colors in
irregular concentric zones, and occurs in nodules, which
are often cut across and polished. Ruin jasper is a variety
with delineations like ruins, of some brownish or yellowish
shade on a darker ground. Porcelain jasper is nothing but
a baked clay, and differs from jasper in being fusible before
the blowpipe. Red felsyte resembles red jasper ; but this
is also fusible, and consists largely of feldspar.
Jasper admits of a high polish, and is a handsome stone
for inlaid work, but is not much used as a gem.
Bloodstone or Heliotrope. Deep green, slightly trans-
lucent, containing spots of red, which have some resem-
blance to drops of blood. It contains a few per cent, of
clay and iron oxide mechanically combined with the silica.
The red spots are colored with iron. There is a bust of
Christ in the royal collection at Paris, cut in this stone, in
which the red spots are so managed as to represent drops
of blood.
Lydian Stone, Touchstone, Basanite. Velvet-black and
opaque, and used, on account of its hardness and black
color, for trying the purity of the precious metals ; this ia
238 DESCRIPTIONS OF MINERALS.
done by comparing the color of the mark left on it with
that of an alloy of known character. The effect of acids
upon the mark is also noted.
Besides the above there are other varieties arising from
structure.
Tabular Quartz. Consists of thin plates, either parallel
or crossing one another and leaving large open cells.
Granular Quartz. A rock consisting of quartz grains
compactly cemented. The colors are white, gray, flesh-red,
yellowish or reddish-brown. It is a hard siliceous sand-
stone. Ordinary sandstone often consists of nearly pure
quartz.
Pseudomorplious Quartz. Quartz under the forms of cal-
cite, barite, fluorite or other mineral. Shells, corals, etc.,
are sometimes found converted into quartz by the ordinary
process of petrifaction.
Silicified Wood. Petrified wood often consists of quartz,
quartz having taken the place of the original wood. Some
specimens are petrified with chalcedony or agate.
Penetrating substances. Quartz crystals are sometimes
penetrated by other minerals. Rutile, asbestus, actinolite,
topaz, tourmaline, chlorite and epidote, are some of these
substances. The rutile often looks like needles or find
hairs of a brown color passing through in every direc-
tion. They are cut for jewelry, and in France pass by the
name of Fleches d* amour (love's arrows). The crystals of
Herkimer County, N. Y., often contain a kind of black coal.
Other crystals contain cavities filled with some fluid, as
water, naphtha, or liquid carbonic acid, or with minute
crystals.
Obs. Quartz is an essential constituent of granite, gneiss,
mica schist, and many other common rocks, and the chief
or only constituent of many sandstones, and of the sands
of most sea-shores. Fine quartz crystals occur in Herki-
mer County, New York, at Middlefield, Little Falls, Salis-
bury and Newport, in the soil and in cavities in a sand-
stone. The beds of iron ore at Fowler and Hermon, St.
Lawrence County, afford dodecahedral crystals. Diamond
Island, Lake George, Pelham and Chesterfield, Mass., Paris
and Perry, Me., Meadow Mt., Md., and Hot Springs, Ar-
kansas, are other localities. Rose quartz is found at Albany
and Paris, Me., Acworth, N. H., and Southbury, Conn.;
quartz at Goshen, Mass. ; Paris, Me. ; in North Caro-.
SILICA. 23ft
lina ; at Pike's Peak, Colorado, and elsewhere ; amethyst at
Bristol, R. L, and Keweenaw Point, Lake Superior ; chalce-
dony and agates of moderate beauty near Northampton,
and along the trap of the Connecticut Valley — but finer
near Lake Superior, upon some of the Western rivers, and
in Oregon ; chrysoprase occurs at Belmont's lead mine, St.
Lawrence County, N. Y., and a green quartz (often called
chrysoprase) at New Fane, Vt., along with fine drusy
quartz ; red jasper occurs on the banks of the Hudson at
Troy ; yellow jasper is found with chalcedony at Chester,
Mass. ; Heliotrope occupies veins in slate at Bloomingrove,
Orange County, N. Y.
Switzerland, Dauphiny, Piedmont, the Carrara quarries,
and numerous other foreign localities furnish fine crystals.
OpaL
Compact and amorphous ; also in renif orm and stalactitic
shapes ; also earthy. Presents internal reflections, often of
several colors in the finest varieties, exhibiting, when turned
in the hand, a rich play of colors of delicate shades. White,
yellow, red, brown, green and gray are some of the shades
that occur, and impure varieties are dark and opaque.
Lustre subvitreous. H. = 5 '5-6 '5. G . = 1 '9-2-3.
Composition. Opal consists of silica, like quartz; but it
is silica in a different molecular state, the hardness and
specific gravity being less; and, besides this, it is soluble in
a strong alkaline solution, especially if heated. It usually con-
tains a few per cent, of water — amounting in some kinds to
12 per cent. ; but the water is not generally regarded as an
essential' constituent.
VARIETIES.
Precious Opal. External color usually milky, but within
there is a rich play of delicate tints. This variety forms a
gem of rare beauty. A large mass in the imperial cabinet
of Vienna weighs seventeen ounces, and is nearly as large
as a man's fist, but contains numerous fissures and is not
entirely disengaged from the matrix. This stone was well
known to the ancients and highly valued by them. They
called it Paideros, or Child Beautiful as Love. The noble
opal is found near Cashau in Hungary, and in Honduras,
South America ; also on the Faroe Islands.
Fire Opal, Girasol. An opal with yellow and bright hya-
240 DESCRIPTIONS OF MINERALS.
cinth or fire-red reflections. It comes from Mexico and the
Faroe Islands.
Common Opal, Semiopal. Common opal has the hardness
of opal and is easily scratched by quartz, a character which
distinguishes it from some siliceous stones often called semi-
opal. It has sometimes a milky opalescence, but does not
reflect a play of colors. The lustre is slightly resinous, and
the colors are white, gray, red, yellow, bluish, greenish to
dark grayish-green. Translucent to nearly opaque. Phillips
found nearly 8 per cent, of water in one specimen.
Hydrophane. This variety is opaque white or yellowish
when dry, but becomes translucent and opalescent when
immersed in water.
Cacholong. Opaque white, or bluish white, and usually
associated with chalcedony. Much of what is so called is
nothing but chalcedony; but other specimens contain water,
and are allied to hydrophane. It contains also a little alu-
mina and adheres to the tongue. It was first brought from
the river Oaoh in Bucharia.
Hyalite, Mullens Glass. A glassy transparent variety, oc-
curring in small concretions and occasionally stalactitic.
It resembles somewhat a transparent gum arabic. Composi-
tion, Silica 92-00, water 6-33 (Bucholz).
Menilite. A brown opaque variety, in compact reniform
masses, occasionally slaty. Composition, Silica 85'5, water
11*0 (Klaproth). It is found in slate at Menil Montant,
near Paris.
Wood Opal. An impure opal, of a gray, brown or black
color, having the structure of wood, and looking much like
common silicified wood. It is wood petrified with a hy-
drated silica (or opal), instead of pure silica, and is distin-
guished by its lightness and inferior hardness. Specific
gravity, 2.
Opal Jasper. Resembles jasper in appearance, and con-
tains a few per cent, of iron ; but it is not so hard, owing to
the water it contains.
Siliceous Sinter has often the composition of opal, though
sometimes simply quartz. The name is given to a loose,
porous siliceous rock usually of a grayish color. It is de-
posited around the Geysers of Iceland and the Yellowstone
Park, in cellular or compact masses, sometimes in fibrous,
stalactitic, or cauliflower-like shapes. It is often called gey-
serite. Pearl sinter, or fiorite, occurs in volcanic tufa in
SILICA. 241
smooth and shining globular, botryoidal masses, having a
pearly lustre.
Float Stone. A variety of opal having a porous and fibrous
texture, and hence so light that it will float 011 water. It
occurs in concretionary or tuberose masses, which often
have a nucleus of quartz.
Tripolite, or Infusorial Earth. A white or grayish-white
earth, made mainly of siliceous secretions of microscopic
plants called Diatoms. It forms beds of considerable extent,
and often occurs beneath peat. It is used as a polishing
powder ; also to mix with nitroglycerine and make dynamite ;
and, owing to its poor conduction of heat, it is applied as a
protection to steam boilers and pipes.
Tabaslieer is a siliceous aggregation found in the joints of
the bamboo in India. It contains several per cent, of water,
and has nearly the appearance of hyalite.
Diff. Infusibility before the blowpipe is the best charac-
ter for distinguishing opal from pitchstone, pearlstone, and
other species it resembles. The absence of anything like
cleavage or crystalline structure is another characteristic.
Its inferior hardness and specific gravity separates it from,
quartz.
Obs. Hyalite occurs sparingly at the Phillips ore bed,
Putnam County, N. Y., and in Burke and Scriven counties,
Georgia. In Washington County, Ga., good fire opal is
obtained. The Suanna Spring in Georgia affords small
quantities of siliceous sinter. Tripolite occurs in Maine,
New Hampshire, Nevada, California, and elsewhere.
Tridymite. Pure silica, like quartz and opal, with very nearly the
hardness and specific gravity of opal, but occurring in tabular hexag-
onal prisms, which are twins under the triclinic system. If not crys-
tallized opal, it is a third state of Si02. It occurs in trachytic and.
some other volcanic rocks. Asmanite is from a meteorite, and may be
the same as tridymite.
Jenzschite. Silica, SiO,, in, it is supposed, a fourth state, it resem-
bling opal in aspect and in solubility in alkaline solutions, but having
the specific gravity of quartz, or 2 6. From Hiittenberg in Carinthia,
resembling a white cachalong ; from near Weissig ; Regensberg ; and
in Brazil.
Melanophlogite. Colorless cubes consisting of silica, with a little
sulphuric trioxide and water. On sulphur from Girgenti, Sicily.
242 DESCRIPTIONS OF MINERALS.
II. SILICATES.
The silicates are here divided into the anhydrous and
the hydrous.
In part of the anhydrous silicates, the combining value
(or quantivalence, see page 77) of the silicon is to that of
the basic elements as 2 to 1 ; in another part, as 1 to 1 ;
and in a third division, as less-than-1 to 1. On this ground
the mineral silicates may be arranged in three groups,
named respectively: I. BISILICATES ; II. UXISILICATES ;
and III. SUBSILICATES.
In the Bisilicates, one molecule of silicon is combined
with one molecule of an element in the protoxide state, as
Mg, Ca, Fe, etc., or one-third of a molecule of an element
in the sesquioxide state, as Al, Fe, Mn, etc.; or, what is
the same thing, 3 molecules of silicon) with 3 of an element
in the protoxide state, or 1 of an element in the sesquiox-
ide state. The general formulas of such compounds is
hence R03Si, orR09Si3, or, if elements in both the pro-
toxide and sesquioxide state are present, (R3 R) 09 Si3, as
explained on page 81.
In the Unisilicates, one molecule of silicon is combined
with two of an element in the protoxide state, that is, for
example, Mg2, Ca2, Fe2 ; or with two-thirds of a molecule in
the sesquioxide state, that is, two-thirds of =41, Fe, Mn.
The formula of these silicates is hence R2 04 Si, or Rf 04
Si, or, in order to remove the fraction in the last, R2
Si3 ; which becomes, when elements in the protoxide and
sesquioxide state are both present, (R3, R)2 0,2 Si3.
Among the species referred to the Unisilicates there are
some that vary from the unisilicate ratio. This occurs
especially in species in which an alkali is present, as in the
feldspars, micas, and scapolites.
The Subsilicates vary in the proportion of the silicon to
the basic elements, and graduate into the Unisilicates.
BISILICATES. 243
The same three grand divisions exist more or less satis-
factorily among the hydrous silicates.
A. ANHYDROUS SILICATES.
I. BISILICATES.
The bisilicates, when the base is in the protoxide state,
and hence have the general formula R 03 Si, are resolved in
analyses into protoxides and silica in the ratio of 1RO to
1 Si 02, in which, as the term bisilieaie implies, the oxygen
of the silica is twice that of the protoxides. If the base is
in both the protoxide and sesquioxide states, giving the for-
mula R3,R09Si3, the mineral is resolved in analyses into
protoxides, sesc|iiioxidcs and silica. If the ratio of the pro-
toxides to sesquioxides is 1 : 1, the formula will become
JR3 JR 09 Si3 ; and analyses give then, for the oxides and
silica 3 RO, 1 R 03 6 Si 0,
Among the following bisilicates the species from ensta-
titc to spodumene and amphibole make a natural group
called the hornblende, or hornblende and augite group.
They are closely related in composition and also in crystal-
lization. The cleavage prism is rhombic, and has either an
angle of about 124£° or of about 87°; and the former of
these two rhombic prisms has just twice the breadth of the
other ; that is, if the lateral axis from the front to the
back edge in each be taken as unity, the other lateral axis
is twice as long in the prism of 124|-° as it is in that of 87°.
The forms are either trimetric, monoclinic or triclinic ;
and yet the close relations just stated exist between them.
Enstatite is a magnesium or magnesium and iron species ;
wollastonite, a calcium species ; rhodonite, a manganese
species ; pyroxene and hornblende contain calcium with
magnesium or iron ; spodumene contains lithium and alu-
minum, aluminum replacing the elements that in other
species are in the protoxide state.
244 DESCRIPTIONS OP MINERALS.
Enstatite.
Trimetric. /A 7=88° 16'. Prismatic cleavage easy.
Usually possesses a fibrous appearance on the cleavage sur-
face. Also massive and lamellar.
Color, grayish, yellowish or greenish-white, or brown.
Lustre pearly ; often metalloidal in the bronzite variety.
H. 5-5. G. 3-1-3-3.
Composition. Mg 03 Si = Silica 60, magnesia 40. B.B. in-
fusible, and insoluble. Bronzite has a portion of the mag-
nesium replaced by iron.
Diff. Resembles amphibole and pyroxene, but is infusi-
ble, and trimetric in crystallization.
Obs. Occurs in the Vosges ; Moravia ; Bavaria ; Baste,
in the Hartz; Leiperville and Texas, Pa. ; Brewster's, N. Y.
Hypersthene is very near bronzite in crystalline form and in com-
position. It contains a larger percentage of iron, and on being heated
B.B. on charcoal it becomes magnetic. Occurs at St. Paul's Island, in
Labrador ; Isle of Skye ; in Greenland ; Norway, etc.
Wollastonite.— Tabular Spar.
Monoclinic. Rarely in oblique flattened prisms. Usually
massive, cleaving easily in one direction, and showing a
lined or indistinctly columnar surface, with a vitreous lustre
inclining to pearly.
Usually white, but sometimes tinged with yellow, red or
brown. Translucent, or rarely subtransparent. Brittle.
H.=4-5-5. G. =2-75-2-9.
Composition. Ca 03 Si = Silica 52, lime 48=100. B.B.
fuses with difficulty to a subtransparent, colorless glass; in
powder decomposed by hydrochloric acid, and the solution
gelatinizes on evaporation; often effervesces when treated
with acid on account of the presence of calcite.
Diff. Differs from asbestus and tremolite in its more viter-
ous appearance and fracture, and by its gelatinizing in acid;
from the zeolites by the absence of water, which all zeolites
give in a closed tube ; from feldspar in the fibrous appear-
ance of a cleavage surface and the action of acids.
Obs. Usually found in granite or granular limestone ;
occasionally in basalt or lava. Occurs in Ireland at Dun-
more Head; at Vesuvius and Capo di Bove ; in the Hartz;
Hungary ; Sweden ; Finland ; Norway.
At Willsboro', Lewis, Diana, and Roger's Rock, N. Y.,
BISILICATES.
245
of a white color, along with garnet ; at Boonville, in bowl-
ders with garnet and pyroxene ; Grenville, Lower Canada ;
in Bucks County, Pennsylvania ; at Keweenaw Point, Lako
Superior. Edelforsite is impure wollastonite.
Pyroxene. — Augite.
Monoclinic. /A 7=87° 5'; cleavage perfect parallel with
the sides of this prism, and also distinct parallel with the
diagonals. Usually in thick and stout prisms, of 4, 6 or 8
sides, terminating in two faces meeting at an edge. I/\i-i
= 133° 33', /A a = 136° 27'; 1 A 1 = 120° 32'. Massive varie-
ties of a coarse lamellar structure ; also fibrous, fibres often
very fine and often long capillary. Also granular, usually
in coarse granular and friable masses ; grains usually angu-
lar ; sometimes round ; also compact massive.
Colors green of various shades, verging to white on one
side and brown and black on the other, passing through
Uue shades, but not yellow. Lustre vitreous, inclining to
resinous or pearly ; the latter especially in fibrous varieties.
Transparent to opaque. H.= 5-6. G!=3'2-3'5.
Composition. It 03 Si ; in which R may be Ca, Mg, Fe,
Mn, and sometimes Zn, K2, Na2, these bases replacing one
another without changing the crystalline form, of which
two or more are usually present ; the first three are most
common. Calcium is always present. The following is an
analysis of a typical variety : Silica 55-0, lime 23'5, magne-
sia 16'5, manganese protoxide *5, iron protoxide 4*5 = 100.
Fuses B.B., but its fusibility varies with the composition,
and the ferriferous varieties are most fusible. Insoluble in
acids.
Diff. Its crystalline form, and its ready cleavage in two
planes nearly at right angles to one another, are the best
characters for its determination.
VARIETIES. — The varieties maybe divided into three sec-
24:6 DESCRIPTIONS OF MINERALS.
tions — the light colored, the dark colored, and the thin
foliated.
I. Mdlacolite or white augite is a calcium magnesium
pyroxene, and includes white or grayish-white crystals or crys-
talline masses. Diopside, of the same composition, occurs in
greenish- white or grayish-green crystals, and cleavable masses
cleaving with a bright smooth surface. Sahlite contains
iron in addition, and is of a more dingy green color, has less
lustre and coarser structure than diopside, but is otherwise
similar ; named from the place Sahla, where it occurs.
Fassaite contains a little alumina in addition to the ele-
ments of sahlite, and is found in crystals of rich green shades
and smooth and lustrous exterior. The name is derived
from the foreign locality Fassa. Coccolite is a general name
for granular varieties, derived from the Greek coccos, grain.
The green is called green coccolite, the white, white coccolite.
The specific gravity of these varieties varies from 3-25 to 3'3.
Asbestus. This name includes fibrous varieties of both
pyroxene and hornblende ; it is more particularly noticed
under the latter species, as pyroxene is rarely asbestiform.
II. Augite includes the black and greenish-black crystals,
which contain a larger percentage of iron, or iron and mag-
nesium, and which mostly present the form in figure 1. Spe-
cific gravity 3-3-3'4. This is the common pyroxene of erup-
tive rocks. Hedenbergite, an iron-calcium pyroxene, is a green-
ish-black opaque variety, in cleavable masses affording a
greenish-brown streak ; specific gravity 3-5. Polylite, Hud-
sonite, and Jcffersonite, fall here ; the last contains some
zinc oxide. These varieties fuse more easily than the pre-
ceding, and the globule obtained is colored black by the
iron oxide.
III. Diallage is a thin-foliated variety, often occurring
imbedded in serpentine and some other rocks. It differs
from bronzite and hypersthene in crystalline form, and in
being fusible.
Obs. Pyroxene is one of the most common minerals. Ifc
occurs in almost all basic eruptive rocks, like doleryte, as an
essential constituent, and is frequently met with in rocks of
other kinds ; common also in granular limestone. In basalt
the crystals are generally small and black or greenish black.
In the other rocks, they occur of all the shades of color
given, and. of all sizes to a foot or more in length. One crys-
tal from Orange County, measured 6 inches in length, and
I1ISILICATES. 24.7
10 in circumference. White crystals occur at Canaan, Conn*,
Kingsbridge, New York County, and the Sing Sing quarries,
'Westell ester County, N. Y. ; in Orange County at several
localities ; green crystals at Trumbull, Conn., at various
places in Orange County, N. Y., Eoger's Rock and other
localities in Essex, Lewis, and St. Lawrence counties. Dark
green or black crystals are met with near Edenville, N. Y.,
Diana, Lewis County. Jeffersonite occurs at Franklin, in
N. J. Green coccolite is found at Roger's Rock, Long Pond,
and Willsboro', N.Y.; black coccolite, in the forest of Dean,
Orange County, N. Y. Diopside, at Raymond and Ritmford,
lie,, HustiYs "farm, Phillipstown, N. Y.
Pyroxene was thus named by Haily from the Greek pur,
fire, 'and xenos, stranger, in allusion to its occurring in lavas,
where, according to a mistake of Hatiy, it did not belong.
The name Augite is from the Greek auge, lustre.
JEgerile. Black to greenish black in color. It is a pyroxene con-
taining nearly 10 per cent, of soda, and much iron sesquioxide. From
near Brevig in Norway ; Hot Springs, Arkansas.
Acmite. In long highly-polished prisms, of a dark-brown or reddish-
brown color, with a pointed extremity, penetrating granite, near Kongs-
berg in Norway. 1 /\ 7=86° 56', resembles pyroxene. Contains over
12 per cent, of soda. Fuses easily before the blowpipe.
Babingtonite. Resembles some varieties of pyroxene . It occurs in
greenish-black splendent crystals in quartz at Arendal in Norway.
Uralite. Has the form of pyroxene but cleavage of hornblende.
Rhodonite. — Manganese Spar, Fowlerite.
Triclinic, but very nearly isomorphous with pyroxene.
Usually massive, the cleavage often indistinct.
Color reddish, usually deep flesh-red ; also brownish,
greenish, or yellowish, when impure ; very often black on
the surface ; streak uncolored. Lustre vitreous. Transpa-
rent to opaque. Becomes black on exposure. H. =5*5-6*5,
G.=3-4-3*7.
Composition. Mn 03 Si — Silica 45*9, manganese protox-
ide 54*1=100. It usually contains a little iron and lime
replacing the manganese. Becomes dark brown when heat-
ed, and, with borax in the outer flame, gives a deep violet
color to the bead while hot, and a red-brown when cold.
Diff. Resembles somewhat a flesh-red feldspar, but dif-
fers in greater specific gravity, in blackening on long ex-
posure, and in the glass with borax.
Obs. Occurs in Sweden, the Hartz, Siberia, and else*
348 DESCRIPTIONS OF MINERALS.
where. In the United States it is found, in masses, at
Plainfield and Cummington, Mass. ; also abundantly at
Hinsdale, and on Stony Mountain, near Winchester, N. H. ;
at Blue Hill Bay, Me. The black exterior is a more or less
pure hydrated oxide of manganese.
Rhodonite may be used in making a violet-colored glass,
and also for a colored glazing on stoneware. It receives a
high polish and is sometimes employed for inlaid work.
Spodumene.
Monoclinic. / A 7=87, being near the angle of pyroxene.
Cleavage easy, parallel to / and i-i. Surface of cleavage
pearly. Color grayish or greenish. Translucent to sub-
translucent. H. = 6 -5-7. G. = 3-1-3 -19.
Composition. (R3, Al) 09Si3, in which R is lithium and
equals Li2, and 3 Li2 is to Al as 1 : 4. This corresponds to
silica 64-2, alumina 29'4, lithia 6-4 = 100. B.B. becomes
white and opaque, fuses, swells up, and imparts to the flame
the purple-red flame of lithia. Unaffected by acids.
Diff. Resembles somewhat feldspar and sea-polite, but
has a higher specific gravity and a more pearly lustre, and
affords rhombic prisms by cleavage. Its lithia reaction is
its most characteristic test.
Obs. Occurs in granite at Goshen ; also at Chesterfield,
Norwich and Sterling, Mass. ; at Windham, Me. ; at Brook-
field and Branchville, Ct.; at Uton, in Sweden; Sterzing
in the Tyrol ; and at Killiney Bay, near Dublin. Cymato-
lite and Killinite are results of its alteration.
This mineral is remarkable for the lithia it contains.
Petalite.
Monoclinic. Usually in imperfectly cleavable masses ;
most prominent cleavage angle 141° 30'. Color white or
gray, or with pale-reddish or greenish shades. Lustre vit-
reous to sub-pearly. Translucent. H. = 6-6'5. G. = 2'5.
Composition. Contains lithia like spodumene, and gives
the percentage — Silica 77'9, alumina 17'7, lithia 3*1, soda
1-3 = 100. Phosphoresces when gently heated. Fuses with
difficulty on the edges. Gives the reaction of lithia like
spodumene.
Diff. Its lithia reaction allies it to spodumene, but it
BISILICATES. 249
differs from that mineral in lustre, specific gravity, and
greater fusibility.
Obs. FromUto, Sweden; also from Elba (Castor or Cas-
lorite).
Amphibole. — Hornblende.
Monoclinic. /A 7=124° 30'. Cleavage perfect parallel
with /. Often in long, slender, flat rhombic
prisms (fig. 2), breaking easily transversely;
also often in 6-sided prisms, with oblique
extremities. Frequently columnar, with a
bladed structure ; long fibrous, the fibres
coarse or fine and often like flax, with a
pearly or silky lustre ; also lamellar ; also
granular, either coarse or fine.
Colors from white to black, passing
through bluish-green, grayish-green, green,
and brownish-green shades, to black.^ Lus-
tre vitreous, with the cleavage face inclining to pearly.
Nearly transparent to opaque. II. = 5-6. G. = 2*9-3*4.
Composition. R 03 Si, as for pyroxene. 11 may corre-
spond to two or more of the basic elements Mg, Ca, Fe, Mn,
Na2, Kr, the first three being most common. Aluminum
is very often present in amphibole, replacing a portion
of the silicon. The blowpipe characters are like those of
pyroxene. It fuses, but the fusibility varies indefinitely,
being easiest in the black varieties.
Diff. It is distinguished by the very ready cleavages pa-
rallel to a prism of 124|-°, while pyroxene cleaves at nearly
a right angle (87° 5').
This species, like pyroxene, has numerous varieties, dif-
fering much in external appearance, and arising from the
same causes — isomorphism and crystallization.
The following are the most important varieties :
I. LIGHT- COLOR ED VARIETIES.
TremoUtc, Grammatite. Tremolite comprises the white
and grayish crystallizations which usually occur in blades
or long crystals penetrating the gangue or aggregated into
coarse columnar forms. Sometimes nearly transparent.
Gr.=2-9. Formula (Ca, Mg) 03 Si = Silica 57*70, magnesia
28*85, lime J 3 '45 = 100. The name is from the foreign lo-
cality, Tremola, in Switzerland.
Actinolite. The light-green varieties. It is a magnesium-
250 DESCRIPTIONS OF MINERALS.
calcium-iron ampliibole. Glassy actinolite includes the bright
glassy crystals, of a rich green color, usually long and slen-
der, and penetrating the gangue like tremolite. Radiated
actinolite includes olive-green masses, consisting of aggre-
gations of coarse acicular fibres, radiating or divergent.
Asbestiform actinolite resembles the radiated, but the fibres
are more delicate. Massive actinolite consists of angular
grains instead of fibres. G. = 3'0-3 *1. The name actino-
lite alludes to the radiated structure of some varieties, and
ij3 derived from the Greek, aktin, a ray of the sun.
Asbestus. In slender fibres easily separable, and some-
times like flax. Either green or white. Amianthus, in-
cludes fine silky varieties. (Much so called is serpentine ;
serpentine is hydrous, and is thereby easily distinguished.)
Ligniform asbestus is compact and hard ; it occurs of brown-
ish and yellowish colors, and looks somewhat like petrified
wood. Mountain leather occurs in thin, tough sheets, look-
ing and feeling a little like kid leather ; it consists of inter-
laced fibres of abestus, and forms thin seams between layers
or in fissures of rocks. Mountain cork is similar, but is in
thicker masses ; it has the elasticity of cork, and is usually
white or grayish white.
The preceding light-colored varieties contain little or no
alumina or iron.
Composition of glassy actinolite : Silica 59-75, magnesia
21*1, lime 14 '25, protoxide of iron 3!9, protoxide of man-
ganese 0*3, hydrofluoric acid 0*8 (Bonsdorf).
Nephrite is a very tough compact variety, related to tre-
molite. Color light-green or blue. It breaks with a splin-
tery fracture and glistening lustre. H. — 6-6*5. G. = 3. It is
a -magnesium-calcium amphibole. Nephrite is made into im-
ages, and was formerly worn as a charm. It was supposed to
be a cure for diseases of the kidney, whence the name, from
the Greek, nephros, kidney. In New Zealand, China and
Western America, it is carved by the inhabitants, or pol-
lished down into various fanciful shapes. It is called jade;
but the aluminum-sodium silicate, called jadeite, is the stone
most highly prized of all those that are called jade. Much
of the mineral from China called jade is prehnite.
II. DARK-COLORED VARIETIES.
Cummingtonite is a magnesium-iron amphibole. Color
gray or brown ; usually fibrous. Named from the locality
where found, Cummington, Mass.
BISILICATES. 251
•»
Pargasite. Dark -green crystals, short and stout (resem-
bling fig. 4), with bright lustre, of which Pargas in Finland
is a noted locality. G. =3*11.
Composition. Silica 45 '5, alumina 14*9, iron protoxide
8*8, manganese protoxide 1*5, magnesia 14'4, lime 14 '9=
100.
Hornblende. Black and greenish-black crystals and mas-
sive specimens. Often in slender crystallizations likeactino-
lite ; also short and stout like figs. 4 and 5, the latter more
especially. It contains a large percentage of iron oxide, and
to this owes its dark color. It is a tough mineral, as is im-
plied in the name it bears. This character, however, is best
seen in the massive specimens. Pargasite and hornblende
contain both alumina and iron.
Composition of a hornblende : Silica 48-8, alumina 7*5,
magnesia 13 '6, lime 10 2, iron protoxide 18 8, manganese
protoxide M^IOO.
Obs. Hornblende is an essential constituent of certain
rocks, as syenyte, dioryte and hornblende schist. Actino-
lite is usually found in magnesian rocks, as talc, steatite or
serpentine ; tremolite in granular limestone and dolomite ;
asbestus in the above rocks and also in serpentine. Black
crystals of hornblende occur at Franconia, N. H., Chester,
Mass., Thomastown, Me., Willsboro', N. Y., in Orange
County, N. Y., and elsewhere. Pargasite occurs at Phipps-
burg and Parsonsfield, Me.; glassy actinolite, in steatite
or talc, at Windham, Readsboro', and New Fane, Vt.,
Middlefield and Blandforcl, Mass.; and radiated varieties
at the same localities and many others. Tremolite and
gray hornblende occiir at Canaan, Ct., Lee, Newburgh,
Mass., in Thomastdff and Raymond, Me., Dover, Kings-
bridge, and in St. Lawrence County, N. Y. ; at Chestnut
Hill, Penn. ; at the Bare Hills, Md. Asbestus at many of
the above localities ; also Brighton and Sheffield, Mass. ;
Cotton Rock and Hustis's farm, Phil lips town, N. Y., near
the Quarantine, Richmond County, N. Y. Mountain lea-
ther is met with at Brunswick, .N. J. Edenite, a white
aluminous kind, occurs at Edenville, N. Y.
Asbestus is the only variety of this species of any use in
the arts. The flax-like variety is sometimes woven into
fire-proof textures. Its incombustibility and slow conduc-
tion of heat render it a complete protection against the
flames. It is often made into gloves. A fabric whea
252 DESCRIPTIONS OF MINERALS.
dirty, need only be thrown into the fire for a few minutes
to be white again. The ancients, who were acquainted with
its properties, are said to have used it for napkins, on ac-
count of the ease with which it was cleaned. It was also
the wick of the lamps in the ancient temples ; and because
it maintained a perpetual flame without being consumed,
they named it asbestos, unconsumed. It is now used for
the same purpose by the natives of Greenland. The name
amianthus alludes to the ease of cleaning it, and it is de-
rived from amiantos, undefiled. Asbestus is extensively
used for lining iron safes, and for protecting steam pipes
and boilers. The best locality for collecting asbestus in the
United States is that near the Quarantine, in Richmond
County, N. Y.
Anthophyllite is related in the angle of its prism to hornblende, but
is trimetric. In composition and its infusibility before the blowpipe,
it is near bronzite. B.B. it becomes magnetic. From Kongsberg in
Norway, and near Modum. Kupfferite has the hornblende angle, but
in composition it is like enstatite, being a magnesium silicate.
Arfvedsonite. Near hornblende ; but contains over 10 per cent,
of soda, like acmite.
Crocidolite. Near arfvedsonite in composition. A lavender-blue or
leek-green fibrous mineral from Orange River, South Africa, and from
the Vosges ; also from Rhode Island (A. H. Chester).
Gastadite. A dark- blue to azure-blue mineral related to amphibole,
from the valleys of Aosta and Locano.
Glaucophane. A bluish mineral with the amphibole angle, from the
Island of Syra. Wichtisite may be the same mineral.
Milarite. Trimetric, of the composition (KH)Cas Al O32 Si12 ; the
quantivalent ratio for bases and silica 1:4; being therefore a quater-
silicate instead of a bisilicate.
Beryl. — Emeraldf^*
Hexagonal. In hexagonal prisms, usually without regular
terminations. Cleavage basal, not very distinct.
Rarely massive.
Color green, passing into blue and yellpw ;
color rather pale, excepting the deep and rich
green of the emerald. Streak uncolored. Lus-
tre vitreous ; sometimes resinous. Transparent
to subtranslucent. Brittle. II. — 7*5-8. G. —
VARIETIES. The emerald is the rich green variety ; it owes
its color to the presence of chromium. Beryl includes the
paler varieties, which are colored by oxide of iron. Aqucv
BISILICATES, 253
marine includes clear beryls of a sea-green, or pale-bluish 01
bluish-green tint.
Composition. Be3Al 0]8Si6 = Silica GO'S, alumina 19*1,
glucina 14 '1 = 100. Emerald contains less than one per
cent, of chromium oxide. B.B. becomes clouded, but does
not fuse ; at a very high temperature the edges are rounded.
Unacted upon by acids.
Diff. The hardness distinguishes this species from apa*
tite ; and this character, and also the form of the crystals,
from green tourmaline.
Obs. The finest emeralds come from Muso, near Santa Fe
in New Grenada, where they occur in dolomite. A crystal
from this locality, 2J inches long and about 2 inches in
diameter, is in the cabinet of the Duke of Devonshire ; it
weighs 8 oz. 18 dwts., and is a regular hexagonal prism. A
more splendid specimen, but weighing only 0 oz., in the
possession of Mr. Hope, of London, cost £500. Emer-
alds of less beauty, but of gigantic size, occur in Siberia.
One specimen in the royal collection of Russia measures 4J
inches in length and 12 in breadth, and weighs IGf pounds
troy. Another is 7 inches long and 4 broad, and weighs 6
pounds. Mount Zalora in Upper Egypt affords a less dis-
tinct variety.
The finest beryls (aquamarines) come from Siberia, Hin-
dostan and Brazil. One specimen belonging to Dom Pedro
is as large as the head of a calf, and weighs 225 ounces, or
more than 1S£ pounds troy ; it is transparent and without a
flaw. In 1827 a fine aquamarine, weighing 35 grams, was
found in Siberia, which is said to have been valued at
600,000 francs.
In the United States, beryls of enormous size have been
obtained, but seldom transparent crystals. They occur in
granite or gneiss. One hexagonal prism from Graf ton, N.
H.. weighs 2,900 pounds and measured 4 feet in length, with
one diameter of 32 inches and another of 22 ; its color was
bluish green, excepting a part at one extremity, which was
dull green and yelloAV. At Royalston, Mass., one crystal haa
been obtained a foot lon<r, and pellucid crystals are some-
times met with. Haddam, Conn., has afforded fine crys-
tals (see the figure). Other localities are Barre, Fitchburg,
Goshen, Mass. ; Albany, Norwich, Bowdoinham and Top-
ham, Me.; Wilmot, N. H. ; Monroe, Portland, Haddam,
Conn. ; Leiperville, Penn.
254: DESCRIPTIONS OF MINERALS.
Phenacite. A beryllium-silicate, rhombohedral in crys«
tallization. From the Urals, and Durango in Mexico.
Eudialyte. A pale rose-red mineral, from West Greenland, occurring
in rliombohedral crystals, and containing 15 '6 per cent, of zirconia.
Eucolite is a related species from Norway.
Pollucite. An isometric ccesium silicate, white, vitreous in lustre,
with G.=2 868. Analysis afforded Rammelsberg Silica 48 15, alumina
16-31, potash 0'47, soda 2 -48, caesium oxide 30 00, water 2'59~100,
giving very nearly the bisilicate formula H,CsaAl 020 Sia. From Elba.
II. UNISILICATES.
For the convenience of the student, the general formulas
of the regular Unisilicates are here re-stated. They are as
follows :
If the base is in the protoxide state alone, the formula is
R2 04 Si, in which R stands for Ca, Mg, Fe, Mn, K2, Na2, or
Li2, or other mutually replaceable base. In analyses, the
mineral is resolved into protoxides and silica, in the ratio
of 2 RO to Si02, in which the oxygen of the silica equals
that of the basic portion.
If the base is in the sesquioxide state alone, the formula
is R2 0J2 Si3, in which R may stand for =41, Fe, or Mn, etc.
Here the mineral is resolved, in analyses, into sesquioxides
and silica in the ratio of 2R03 to 3 Si 03, in which the oxy-
gen of the silica again equals that of the basic portion.
If the basic portion is partly in the protoxide state and
partly in the sesquioxide, the formula, in its most general
form, is (R3, R)2 0]2 Si3. In this formula the ratio of R3 to
R is not stated. If the ratio is 1 : 1, the formula becomes
R3R 0,a Si3, or its equivalent (£R3 JR)2 012 Si, In a case like
this last, the mineral is resolved, in analyses, into protoxides,
sesquioxides and silica, in the ratio of 3RO :R03 : 3 Si O2,
in which again the oxygen of the bases equals that of the
silica*
If the proportion of R3 to R is 1 : 3, this corresponds to
JR8 : R, or, its equivalent, R : R ; and hence the formula in
its general form will be RR 08 Si*
TJNISILICATES.
255
If the base is in the dioxide state, the formula becomes
K04Si, an example of which occurs in zircon, whose for-
mula is Zr 04 Si.
There are several natural groups of species among the
Unisilicates.
GROUP.
1. Chrysolite group,
2. Willemite group,
8. Garnet group,
4. Zircon group,
5. Idocrase and Sea-
polite groups,
6. Mica group,
7. Feldspar group,
STATE OF BASES.
protoxide,
protoxide,
protoxide and)
sesquioxide, y
dioxide,
protox. and ses-
quiox.
protox. and ses-
quiox .
protox. and ses- \
quiox. C
CRYSTALLIZATION.
Trimetric.
Hexagonal.
Isometric.
Dimetric.
Dimetric.
Tiimetric ; plane angle
of base, 120° ; mica-
ceous.
Monoclinic or triclinic,
/A /nearly 120°.
Ill the Scapolite, Mica and Feldspar groups part of the
species contain an alkaline metal in the basic portion, and
such kinds have generally an excess of silica. Among the
feldspars, the species containing only calcium as the protox-
ide base, is a true Unisjlicate. In the others, there is an
excess directly proportional to the increase of the soda, as
explained beyond.
Chrysolite. — Olivine.
Trimetric. In rectangular prisms having cleavage par-
allel with i-L Usually in imbedded grains of an olive-
green color, looking like green bottle-glass. Also yellow-
ish green. Transparent to translucent. H.:=6-7. G.=3'3
-3'5. Looks much like glass in the fracture, except in its
having cleavage.
Composition. (Mg, Fe)904Si = , for a common variety,
Silica 41-39, magnesia 50'90, iron protoxide 7'71 = 100.
The amount of iron is variable. B.B. whitens but is in-
fusible. With borax forms a yellow bead owing to the iron
present. Decomposed by hydrochloric acid, and the solu-
tion gelatinizes when evaporated. Hyalosiderite is a very
ferruginous variety which fuses B.B.
Diff. Distinguished from green quartz by its occurring
256
DESCRIPTIONS OF MINERALS.
disseminated in basaltic rocks, which never so occurs ; and
in its cleavage. From obsidian or volcanic glass it differs
in its infusibility.
Obs. Occurs as a rock formation ; also disseminated
through basalt and other eruptive rocks, and is a charac-
teristic mineral of some varieties of them. Has been
found in New Hampshire, Canada, and elsewhere. As a
rock it occurs in North Carolina, and Pennsylvania. It
also occurs in many meteorites. Boltonite, from limestone
at Bolton, Mass., is a variety of chrysolite.
Sometimes used as a gem, but it is too soft to be valued,
and is not delicate in its shade of color.
Forsterite is a magnesian chrysolite Mga (X Si ; Fayalite, an iron
chrysolite, Fe2 04 Si ; Monticellite, a calcium-magnesium, CaMga O4 Si ;
Hortonolite, an iron-magnesium chrysolite from Orange County, N. Y. ;
Rwpperite, an iron-manganese-zinc chrysolite from Stirling Hill, N. J. ;
Tephroite, a manganese chrysolite Mn2 O4 Si, from Stirling Hill, N. J. ;
Knebelite, a manganese- iron chrysolite, MnFe04Si, from Dannemora,
Sweden.
Leucoplianite and meliplianite are species containing the element
glucinum (beryllium), the former greenish yellow and G=2'97, the
latter yellow and G=3'018. From Norway.
Wohlerite contains zirconium, and also columbium ; color light yel-
low. G=3'41.
Willemite is a zinc unisilicate, Zn204 Si. See page 157.
Dioptase is a copper silicate, which, making the water basic, is a
uniailicate, H2CuO4Si. See page 141.
Friedelite is a rose-red manganese silicate of the general formula
R2 04 Si, in which R consists of manganese and hydrogen in the atomic
ratio 2 : 1.
IMmte (Helvin). Isometric ; in tetrahedral crystals. Color honey-
yellow, brownish, greenish. Lustre vitreo - resinous. H.— 6-6 '5.
G. =3'1 3'3. Contains manganese, iron, and glucinum, and some
sulphur. From Saxony, and Norway.
Danaiite. Isometric ; in octahedral crystals. Color flesh-red to
gray. Lustre vitreo-resinous. H. =5-5. G. =3 '427. Contains zinc,
glucinum, iron, manganese. Found disseminated through the granite
at Rockport, Cape Ann, Mass., and also near Gloucester, Mass.
Eulytite is a bismuth silicate, and Bismutoferrite a bismuth-and-
iron silicate.
Garnet.
Isometric. Common in dodecahedrons (fig. 1), also in
trapezohedroris (fig. 2), and both forms are sometimes vari-
ously modified. Cleavage parallel to the faces of the dode-
cahedron ; sometimes rather distinct. Also found massive
granular, and coarse lamellar.
UNISILICATES. 257
Color deep red to cinnamon color ; also brown, black,
green, emerald-green, white. Transparent to opaque. Lus-
tre vitreous. Brittle. H. =6-5-7*5. G. =3-1-4-3.
Composition and Varieties. The general formula for the
species is (R3Kr)2 0,2Si3; in which 1? may be calcium, mag-
nesium, iron, manganese, and R may be aluminum, iron,
chromium. The varieties owe their differences to the pro-
portions of these elements, or the substitution of one for
another. Most garnets fuse easily to a brown or black glass ;
but the fusibility varies with the constituents, and chrome-
garnet is infusible. They are not decomposed by hydro-
chloric acid ; but if first ignited, then pulverized and treated
with acid, they are decomposed, and the solution usually
gelatinizes when evaporated.
There are three series among the varieties : one, that of
alumina-garnet, in which the sesquioxide base is chiefly
aluminum ; the second, that of iron-garnet, in which the
sesquioxide base is chiefly iron instead of aluminum ; and
third, chrome-garnefc, in which it is chromium.
I. ALUMINA-GARNET.
Almandite (Almandine). An iron alumina-garnet, Fe3
Al Oi2Si3= Silica 36*1, alumina 20'6, iron protoxide 43*3 =
100. It occurs of various shades of red from ruby-red and
hyacinth-red, to columbine-red and brownish red. When
transparent it is called precious garnet ; and, if not so,
common garnet.
Grossularite (including Cinnamon Stone}. A lime alu-
mina-garnet, Ca3Al 012Si3= Silica 40*1, alumina 22*7, lime
37-2 = 100, but often with some iron protoxide in place of
part of the lime. The name Grossularite was given to a
pale-green garnet, in allusion to the color, from the Latin
name for gooseberry. Cinnamon Stone includes the cinna-
mon-colored variety.
258 DESCRIPTIONS OP MINERALS.
Pyrope. A magnesia alumina-garnet Mg3Al 012Si3. Color
deep red, but varying to black and green.
Spessartite. A manganese alumina-garnet (Mn,Fe)3Al
O,2 Sit, some iron replacing part of the manganese. Color
red, brownish red, hyacinth-red. A Haddam specimen af-
forded Seybert, Silica 35 '8, alumina, 18-1, iron protoxide
14*9, manganese protoxide 31*0.
II. IRON-GARNET.
Andradite. A lime iron-garnet, Ca3Fe012Si3. Colors
various, from that of almandite or common garnet, to a
wine-yellow, as in Topazolite ; green, as in Jelletite ; and
black, as in Melanite and Pyreneite.
ColopJwnite is a dark-red to brownish-yellow coarse gran-
ular garnet having often iridescent hues.
Aplome is a red variety. Rothoffite has manganese in place
of part of the lime, and a yellowish-brown to reddish-brown
color.
Ytter-garnet contains yttria in place of part of the lime.
Bredbergite. A lime-magnesia iron-garnet.
III. CHROME-GARNET.
Ouvarovite. An emerald-green lime chrome-garnet (Ca,
Mg)3Ee012Si3. G. = 3-41-3-42.
Diff, The vitreous lustre of fractured garnet, and its
usual dodecahedral forms, are easy characters for distin-
guishing it.
Obs. Garnet occurs abundantly in mica schist, horn-
blende schist, and gneiss, and somewhat less frequently in
granite and granular limestone ; sometimes in serpentine;
occasionally in trap, and other igneous rocks.
The best precious garnets are from Ceylon and Green-
land ; cinnamon stone comes from Ceylon and Sweden ;
grossularite occurs in the AVilui River, Siberia, and at Tel-
lemarken in Norway ; green garnets are found at Schwartz-
enberg, Saxony ; melanite, in the Vesuvian lavas ; ouvaro-
vite^at Bissersk in Russia; topazolite, at Mussa, Piedmont.
In the United States, precious garnets, of small size, oc-
cur at Hanover, N". H. ; and a clear and deep red variety,
sometimes called pi/rope, comes from Green's Creek, Dela-
ware County, Penn. Dodecahedrons, of a dark red color,
occur at Haverhill and Springfield, N, H., some 1£ inches
through; also at New Fane, Vt., still larger; at Unity,
Brunswick, Streaked Mountain, and elsewhere, Maine ; at
Monroe, Lyme and Redding, Conn. ; Bedford, Chesterfield,
UNISILICATES.
259
Barre, Brookfield, and Brimfield, Mass. ; Dover, Dutchess
County. Roger's Rock, Crown Point, Essex County, N. Y. ;
Franklin, N. J. Cinnamon-colored crystals occur at Carlisle,
Mass., transparent, and also at Boxborough ; with ido-
crase at Parsonstield, Phippsburg and Rumford, Me. ; afc
Amherst, N. H. ; at .Amity, K. Y., and Franklin, N. J. ;
at Dixon's Quarry, seven miles from Wilmington, Del., in
fine trapezohedral crystals. Melanite is found at Franklin,
N. J., and German town, Perm. Chrome garnet is found
in Orford, Canada. Oolophonite is abundant at Willsbor-
ough and Lewis, Essex County, H. Y. : it occurs also at
North Madison, Conn.
The garnet is the carbuncle of the ancients. The ala-
bandic carbuncles of Pliny were so called because cut and
polished at Alabanda, and hence the name Almandine now
in use. The garnet is also supposed to have been the hya-
cinth of the ancients.
The clear deep-red garnets make a rich gem, and are
much used. Those of Pegu are most highly valued. They
are cut quite thin, on account of their depth of color. The
cinnamon stone is also employed for the same purpose.
Pulverized garnet is sometimes employed as a substitute
for emery.
Pliny describes vessels, of the capacity of a pint, formed
from large carbuncles, "devoid of lustre and transpa-
rency, and of a dingy color/' which probably were large
garnets.
Zircon.
Dimetric. /A/=132°10'; 1M = 123°19'. Cleavage parallel
to /, but imperfect. Usually in crystals ; but also granular.
1.
Color brownish red, brown, and red, of clear tints ; also
yellow, gray, and white. Streak uncolored. Lustre more
or less adamantine. Often transparent ; also nearly opaque.
Fracture conchoidal, brilliant. H. = 7'5. G. — 4-0-4*8.
•360 DESCRIPTIONS OP MINERALS.
Composition. Zr O4 Si = Silica 33, zirconia 67=100. B.B.
infusible, but loses color.
VARIETIES. Transparent red specimens are called hya-
cinth. A colorless variety from Ceylon, having a smoky
tinge, is called jargon; it is sold for inferior diamonds,
which it resembles, though much less hard. The name
zirconite is sometimes applied to crystals of gray or brown-
ish tints.
Diff. Zircon is readily distinguished from species which
it resembles in other properties by its square prismatic
form, specific gravity, and adamantine lustre.
Obs. The zircon is confined to crystalline rocks, occurring
in granite, gneiss, granular limestone, and some igneous
rocks. Zircon-syenyte is a syenyte with disseminated zircons.
Zircon often occurs in auriferous sands. Hyacinth occurs
mosth in grains in such sands, and comes from Ceylon,
Auvergne, Bohemia, and elsewhere in Europe. Siberia
affords crystals as large as walnuts. Splendid specimens
come from Greenland.
In the United States, fine crystals of zircon occur in Bun-
combe County, N. C. ; of a cinnamon-red color in Moriah,
Essex County, N. Y. ; also at Two Ponds and elsewhere,
Orange County, in crystals sometimes an inch and a half
long ; in Hammond, St. Lawrence County, and Johnsbury,
Warren County, N. Y. ; at Franklin. N. J. ; in Litchfield,
Me. ; Middlebury, Vt. ; in Canada, at Grenville, etc.
The name hyacinth is from the Greek huakinthos. But
it is doubtful whether it was applied by the ancients to
stones of the zircon species.
The clear crystals (hyacinths) are of common use in
jewelry. When heated in a crucible with lime, they lose
their color, and resemble a pale straw-yelloAV diamond, for
which they are substituted. Zircon is also used in jeweling
watches. The hyacinth of commerce is to a great extent
cinnamon stone, a variety of garnet. The earth zirconia
is used as an advantageous substitute for lime in the oxyhy-
drogen lantern.
Auerbachite, Malacon, Tachyaphcdtite, CErstedite, Bragite, are
names of zircon-like minerals supposed to be zircon partly altered.
The earth zirconia is also found in the rare minerals eudialyte and
wohlerite ; also in polymignite, ceschynite; also sparingly in
wnite.
UNISILICATES.
261
Vesuvianite. — Idocrase.
Dimetric. 0 : 1 = 142° 46' ; 1 Al=129° 21', 1 : ^'=127°
14'. Cleavage not very distinct parallel with /. Also found
massive granular, and subcolumnar.
4.
Color brown ; sometimes passing into green. In some
varieties the color is oil-green in the direction of the axis
and yellowish green at right angles with it. Streak un-
colored. Lustre vitreous. Subtransparent to nearly opaque.
H. = 6-o. G.=3-33-3-4.
Composition. (fCa3-fAl)2012 Si3. A small part of the
Ca is usually replaced by magnesium, and part of the alu-
minum sometimes by iron in the sesquioxide state. Per-
centage of a common variety, Silica 37'3, alumina 16'1,
iron sesquioxide 3-7, lime 35 -4, magnesia 2-1, iron protox-
ide 2*9, water 2*1 = 99 '6. B.B. fuses easily with efferves-
cence to a greenish or brownish globule.
Diff. Resembles some brown varieties of garnet, tourma-
line and epidote, but besides its difference of crystallization,
it is much more fusible.
Obs. Vesuvianite was first found in the lavas of Vesuvius,
and hence the name. It has since been obtained in Pied-
mont ; near Christiania, Norway ; in Siberia ; also in the
Fassa Valley. Cyprine includes blue crystals from Telle-
marken, Norway ; supposed to be colored by copper.
In the United States, it occurs in fine crystals at
Phippsburg and Rumford, Sandford, Parsonsfield and
Poland, Me. ; Newton, N. J.; Amity, N. Y. In Canada at
Calumet Falls, and at Grenville.
The name idocrase is from the Greek eido, to see, and
krasis, mixture ; because its crystalline forms have much
resemblance to those of other species.
This mineral is sometimes cut as a gem for rings.
MellUite in honey-yellow crystals (which includes Hum-
DESCRIPTIONS OF MINERALS.
"boldtilite) is a related dimetric species, from Capo di Bove,
near Eome, and Mount Somma, Vesuvius,
Epidote.
Monoclinic. i-iM t = 115°24'. t-i'A — l-i = 116° 18'. — lA
-1 = 109° 35'. Cleavage parallel to
i-i ; less distinct parallel to 1-i.
Also massive granular and forming
rock masses ; sometimes columnar
or fibrous.
Color yellowish green (pistachio-
green) and ash-gray or hair-brown. Streak uncolored.
Translucent to opaque. Lustre vitreous, a little pearly
on i-i ; often brilliant on the faces of crystals. Brittle. H.
= 6-7. G. = 3'25-3'5.
Composition. A lime iron-alumina silicate, the iron being
mostly in the sesquioxide state and replacing aluminum.
Percentage of common variety, Silica 37 '83, alumina 22-63,
iron sesquioxide 15-02, iron protoxide 0'93, lime 23*27,
water 2 -05 =100 -73.
B.B. epidote fuses with effervescence to a black glass
which usually is magnetic. Partially decomposed by hy-
drochloric acid, but if first ignited, is then decomposed,
and the solution gelatinizes on evaporation.
Green epidote is often called Pistacite. Piedmontite is
a variety containing much manganese, of reddish -brown or
reddish-black color.
Bucklandite is an iron-epidote.
Diff. The peculiar yellowish-green color of ordinary epi-
dote distinguishes it at once. From zoisite and vesuvian-
ite it differs in fusing to a black magnetic globule.
Obs. Occurs in crystalline rocks, especially in hornblen-
dic rocks. It often occurs in the cavities of amygdaloidal
rocks. Splendid crystals, six inches long, and with bril-
liant faces and rich color, have been obtained at Haddam,
Ct. Crystallized specimens are also found at Franconia,
N. H./Hadlyme, Chester, Newbury and Athol, Mass.;
near TJnity, Amity, and Monroe, $T. Y. ; Franklin and
Warwick, N. J. ; Pennsylvania, at E. Bradford ; Michigan,
in the Lake Superior region ; Canada, at St. Joseph.
The name epidote was derived by Haiiy from the Greek
epidiclomi, to increase, in allusion to the fact that the base
of the primary is frequently mu^h enlarged in the crystals.
UNISILICATES. 263
Zoisite. A mineral of the epidote group, occurring in trimetric crys-
tals, with /A/=H6° 40', and having- a white, pale-grayish, pale-
greenish to reddish color ; also massive. H. =6-6*5. G. =3*1-3*4.
It is a lime-epidote, with little or no iron. B.B. swells up and
fuses to a white blebby glass ; after ignition, gelatinizes with hydro-
chloric acid. Thulite is a rose-red variety. Occurs at Saualpe in Carin-
thia, in the Tyrol ; Arendal, etc. ; in Vermont at Willsboro' and Mont-
pelier ; in Massachusetts, at Goshen, Chesterfield, etc. ; in Pennsyl-
vania at Unionville, and in Tennessee at the Ducktown copper mine.
Saussurite, from the euphotide of the Alps in the vicinity of Lake
Geneva, approaches zoisite in composition, it affording Hunt Silica
43*59, alumina 27 '72, iron sequioxide 2'61, magnesia 2*98, lime 19'71,
water 0-35, soda 3'08 = 100'04. Color whitish, greenish gray, ash-gray ;
G. =3 226-3*385. H.=6'5-7. The saussurite of Orezza gave nearly the
same composition in an analysis by Boulanger, and that of Schwartz-
wald in general the same, with more of magnesia and less of lime, in
an analysis by Hutlin. The high specific gravity separates it from
scapolite (wernerite) which it resembles in composition, and also from
the feldspar group.
Jadeite, one of the kinds of pale-green stones used in China for
ornaments, called feitsui, has the high specific gravity of zoisite, but
it has nearly the composition of oligoclase, if the iron and magnesia
be excluded; analysis by Damour affording "Silica 59 '17. alumina
22-58, iron protoxide 1 "56, magnesia 115, lime 2 '68, soda 12 *93 = 100 "07.
It is the material of some of the ornaments in the Swiss lake-dwell-
ings.
Allanite. — A cerium epidote, of a pinchbeck-brown to brownish-
black and black color, submetallic to pitch-like and resinous in lustre,
crystallizing in the monoclinic system, and with the angles nearly of
epidote. H. =5*5-6. G. =3-4*2.
B.B. fuses easily and swells up to a dark, blebby magnetic glass.
Most varieties gelatinize with hydrochloric acid, but not after igni-
tion. Found in Norway, Sweden, Greenland, Scotland ; at Snarum,
near Dresden ; in Massachusetts, at the Bolton quarry ; in New York,
at Moriah in Essex County, Monroe in Orange County ; in New Jersey,
at Franklin; in Pennsylvania, at East Bradford and Eaton ^ in Vir-
ginia, Amherst County ; in Canada, at St. Paul's.
Orthite is a variety in long slender crystals. Muromontite, Bodcnite,
and Michaelsonite are related minerals.
Gadolinite. A mineral of a greenish-black color, containing lithium,
cerium, and barium, from Sweden, Greenland, and Norway. Crystals
monoclinic, with 1 A /= 116°. H.=6*5-7. G.=4-4'5.
Mosandrite. Reddish-brown to dull greenish or yellowish-brown
silicate of cerium, lanthanum and didymium, calcium, and titanium.
H.=4. G. =2*9-3-03. From Brevig, Norway.
llvaite ( Yenite). In trimetric striated prisms, of an iron-black to
grayish-black color. /A/=112° 38'. H.=5'5-6. G.=3 7-4'2. In
composition a calcium-iron silicate in which part of the iron h in
the sesquioxide state. From Elba; Fossum and Skeen in NOT ^ay,
etc. Also reported as occurring at Cumberland, R. I., and Milk /tow
quarry, in Somerville, Mass. The name Ifaaite is derived frotp the
Latin name of the Island of Elba,
264
DESCRIPTIONS OF MINERALS.
Axinite.
Triclinic. In acute-edged oblique rhomboidal prisms ;
° ' ° ' =° '
45'
38', PAw=135° 31'. Cleavage
indistinct. Also rarely massive or lamellar.
Color clove-brown ; differing some-
what in shade in three directions, being
trichroic. Lustre vitreous. Transpa-
rent to subtranslucent. Brittle. H. =
6-5-7. G.=3'27. Pyro-electric.
Composition. A unisilicate, afford-
ing boron trioxide, and containing
boron among its bases. One analysis
afforded Silica 43-68, boron trioxide
5-61, alumina 15-63, iron sesquioxide
9-45, manganese sesquioxide 3-05, lime
20-92, magnesia T70, potash 0-64=
100-43. B.B. fuses easily with intum-
escence to a dark-green or black glass,
imparting a pale-green color to the
flame, which is due to the boron.
Diff. Remarkable for the sharp thin edges of its crystals,
and its glassy brilliant appearance, without cleavage. The
crystals are implanted, and not disseminated like garnet. In
one or all of these particulars, and also in blowpipe reaction,
it differs from any of the titanium ores.
Obs. Occurs at St. Cristophe in Dauphiny ; at Kongs-
berg in Norway ; Normark in Sweden ; Santa Maria, in
Switzerland ; Cornwall, England ; Thum in Saxony, whence
the name T hummer stein and Thumite.
In the United States it has been found at Phippsburg and
"Wales in Maine ; and at Cold Spring, New York.
Dariburite. A silicate which contains, like axinite, boron trioxide.
Composition: Silica 48 '8, boron trioxide 28-5, lime 22'7. Occurs with
oligoclase and orthoclase in imbedded masses of a pale-yellow color,
at Danbiiry, Conn. H.=7. G.=2-95-2'96.
lolite. — Dichroite. Cordierite.
Trimetric. In rhombic prisms of 120°, and in 6 and 12-
sided prisms. Also massive. Cleavage indistinct ; but crys-
tals often separable into layers parallel to the base, especially
after partial alteration.
Color various shades of blue, looking often like a pale or
MICA GROUP. 265
dark blue glass ; often deep blue in direction of the axis, and
yellowish gray transversely. Streak uncolored. Lustre vit-
reous. Transparent to translucent. Brittle. H. =7-7'5.
G. =2-6-2-7.
Composition. A silicate of aluminum, magnesium and
iron, corresponding to Silica 49*4, alumina 33*9, magnesia
8-8, iron protoxide 7-9 = 100. B.B. loses its transparency
and with much difficulty fuses.
Diff. The glassy appearance of iolite is so peculiar that it
can be confounded with nothing but blue quartz, from which
it is distinguished by its fusing on the edges. It is easily
scratched by sapphire.
Obs. Found atHaddam, Conn., in granite ; also in gneiss
at Brimfield, Mass.; at Richmond, N. H., in talcose rock.
The principal foreign localities are at Bodenmais in Bavaria;
Arendal, Norway ; Capo de Gata, Spain ; Tunaberg, Fin-
land ; also Norway, Greenland and Ceylon.
The name iolite is from the Greek ion, violet, alluding
to its color ; it is also called dichroite, from dis, twice, and
chroa, color, owing to its having different colors in two di-
rections.
Occasionally employed as an ornamental stone, and is cut
so as to present different shades of color in different direc-
tions.
Iolite exposed to the air and moisture undergoes a gradual altera-
tion, becoming hydrous, and assuming a foliated micaceous structure,
so as to resemble talc, though more brittle and hardly greasy in feel.
Hydrous Iolite, FaMunite, Chlorophyllite, and EsmarJdte, are names
that have been given to the altered iolite ; and Gigantolite and a num-
ber of other like minerals are of the same origin. (See p. 315.)
MICA GROUP.
The minerals of the mica group are alike in having
(1) their crystals monoclinic ; (2) the front plane angle of
the base, or of the cleavage laminae, 120°; (3) cleavage emi-
nent, parallel to the base, affording very thin laminae ; and
(4) aluminum and potassium among the essential constituents.
The combining or quantivalent ratio for the bases and sili-
con is usually 1 to 1 in Biotite, Phlogopite, and Lepidome-
lane ; 1 to more than 1 in Muscovite, Lepidolite, etc.
266 DESCRIPTIONS OF MINERALS.
The ordinary light-colored micas are mostly Muscovite, and
the black, mostly Biotite. Lepidolite is a light-colored mica
containing lithia ; and Lepidomelane a black mica containing
more iron than biotite. Muscovite and biotite are so closely
related that crystals of the latter often occur that are fin-
ished out uninterruptedly by muscovite, the axial lines of the
one continuous with those of the other; and such crystals
are sometimes several inches across. There is here a com-
pound structure chemically, but no twinning in the crystal-
lization. When a thin plate of mica is struck with a pointed
awl or other tool a symmetrical star of six rays is produced,
the rays being cleavage lines parallel to the sides of the
rhombic prism / and the shorter diagonal.
Biotite.
Monoclinic. Crystals usually short erect rhombic or hex-
agonal prisms. Common in disseminated scales ; also in
masses made up of an aggregation of scales.
Color dark green to black, rarely white. Transparent to
opaque. Lustre more or less pearly on a cleavage surface.
Optic-axial angle usually less than 1° ; crystals appear often
to beuniaxial. H. =2-5-3. G. =2-7-3-1.
Composition. Mostly (K2,Mg,Fe)3 Al 0]2Si6, a variety af-
forded Silica 40-91, alumina 17 '79, iron oxides 10-00, mag-
nesia 19-04, potash 9-96. B.B. whitens and fuses on thin
edges ; sometimes the flame is red owing to the presence of
a little lithium.
Lepidomelane. Like biotite, but containing more iron oxides and
less of magnesia than biotite, and folia brittle. Puses easily to a
black magnetic globule. Annite (from Cape Ann, Mass.) is near Lepi-
domelane.
Phlogopite. Contains much magnesia and little or no iron. Color
yellowish brown to brownish red, somewhat copper-like in its reflec-
tions ; also white or colorless. Optic-axial angle 3° to 20'. H.=2 5-3.
G.=r2'78-2-85. In crystals and scales in granular limestone Prom
Gouverneur, Edwards, and other places in Northern New York ; Stir-
ling Mine, and Newton, N. J. ; St. Jerome, and Burgess, Canada ; in
the Vosges. Aspidolite, from the Tyrol, is a related mica.
Astrophyllite. A bronze-yellow mica affording nearly 8 per cent, of
titanium dioxide. From Brerig, Norway, and El Paso County, Colo-
rado.
MICA GROUP. 267
Muscovite. — Common Mica.
Monoclinic. In oblique rhombic prisms of about 120°.
Crystals commonly have the acute edge replaced, as in the
accompanying figure (plane i-i). Usu-
ally in plates or scales. Sometimes in
radiated groups of aggregated scales or
small folia.
Colors from white through green,
yellowish and brownish shades ; rarely
rose-red. Lustre more or less pearly.
Transparent or translucent. Tough
and elastic. H.=2-2-5. G.=2'7-3.
Optic-axial angle 44° to 78°.
Composition. A common variety afforded Silica 46-3,
alumina 36-8, potash 9-2, iron sesquioxide 4-5, fluoric acid
0*7, water 1*8— 99*3. Often contains 3 to 5 per cent, of
water, and thus passes to a hydrous mica called Margaro-
dite. (See page 313). B.B. whitens and fuses on the thin-
nest edges, but with great difficulty, to a gray or yellow
glass.
A variety in which the scales are arranged in a plu-
mose form is called plumose mica ; another, in which the
plates have a transverse cleavage, has been termed. prismatic
mica.
Diff. Differs from talc and gypsum in affording thinner
and much tougher folia, and in being elastic ; but musco-
vite when hydrous loses its elasticity, and becomes more
pearly in lustre.
Obs. Muscovite is a constituent of granite, gneiss and mica
schist, and gives to the latter its schistose structure. It also
occurs in granular limestone. Plates two and three feet in
diameter, and perfectly transparent, have been obtained at
Alstead, and Grafton, New Hampshire, and it has been
mined at these places, and in Orange and elsewhere. Other
good localities are Paris, Me. ; Chesterfield, Barre, Brimfield,
and South Royalston, Mass. ; near Greenwood Furnace, War-
wick and Edenville, Orange County, and in Jefferson and
St. Lawrence counties, N. Y . ; Newton and Franklin, N. J. ;
near Germantown, Pa.; Jones's Falls, Maryland. Oblique
prisms from near Greenwood are sometimes six or seven
inches in diameter. Western North Carolina affords much
mica for commerce.
268
DESCRIPTIONS OF MINERALS.
A green variety occurs at Unity, Maine, near Baltimore,
Md., and at Chestnut Hill, Pa. Prismatic mica is found at
Eussel, Mass.
On account of the toughness, transparency, and the thin-
ness of its folia, mica was formerly used in Siberia for glass in
windows, whence it has been called Muscovy glass. It is in
common use for lanterns, and alsg for the doors of stoves,
and other purposes which demand a transparent substance
not affected by heat.
Lepidolite, or Lithia mica. Resembles muscovite. Color rose-red,
and lilac to white ; in crystalline plates and aggregations of scales.
It contains from 2 to 5 per cent, of lithia, and hence B.B. imparts a
deep crimson color to the flame.
From Rozena in Moravia ; Zinnwald in Bohemia (the Zinnwaldite] ;
Saxony ; the Ural ; Sweden; Cornwall; Paris, and Hebron, Maine;
Chesterfield, Mass. ; Middletown, Conn. The red mica of Goshen is
muscovite.
Cryophyllite has the same constituents as lepidolite. It fuses easily
in the flame of a candle. From Cape Ann, Mass.
SCAPOLITE GROUP.
The Scapolite species are dimetric in crystallization,
usually white in color or of some light shade, and analyses
afford alumina and lime with or without soda. The lime
scapolites are unisilicate in ratio ; the others, containing
alkali, have, with one exception, more silica than this ratio
requires.
Wernerite. — Scapolite
= 136° 7". Cleavage rather indistinct paral-
lel with i-i and /. Also massive, sub-
lamellar, or sometimes faintly fibrous
in appearance.
Colors light ; white, gray, pale blue,
greenish or reddish. Streak uncolored.
Transparent to nearly opaque. Lustre
usually a little pearly. H. = 5-6. G. =•
2-6-2-8.
Composition. (-J-(Ca,Na2)f Al)2012 Si3=
Silica 48-4, alumina 28-5, lime 18-1,
soda 5-0— 100. B.B. fuses easily with intumescence to a
white glass. Imperfectly decomposed by hydrochloric acid.
Dimetric. 1
UNISILICATES. 269
Diff* Its square prisms and the angle of the pyramid at
summit are characteristic. In cleavable masses it resembles
feldspar, but there is a slight fibrous appearance often dis-
tinguished on the cleavage surface of scapolite, which is
peculiar. It is more fusible than feldspar, and has higher
specific gravity. Spodumene has a much higher specific
gravity, and differs in its action before the blowpipe. Tabu-
lar spar is more fibrous in the appearance of the surface,
and is less hard ; it also gelatinizes with acids.
Obs. Found mostly in the older crystalline rocks, and also
in some volcanic rocks. It is especially common in granular
limestone. Fine crystals occur at Grouverneur, N. Y., and
at Two Ponds and Amity, N. Y. ; at Bolton, Boxborough
and Littleton, Mass.; at Franklin and Newton, N. J. It
occurs massive at Marlboro', Vt. ; Westfield, Mass. ; Monroe,
Ct. Foreign localities are at Arendal, Norway ; Wiirmland,
Sweden ; Pagas in Finland, and also at Vesuvius, whence
come the small crystals called meionite.
Nuttallite, Glaucolite, are varieties of this species.
Ekebergite resembles wernerite, being distinguishable from it only
by chemical analysis. Dipyre also is near wernerite, but contains
more silica and 10 per cent, of soda ; from the Pyrenees.
Meionite, a lime scapolite, is like wernerite in its crystals, but has
the formula (^CafAl)2O12Si3, being a true unisilicate. From Monte
Somma.
Mizzonite and Marialite resemble meionite. Paranthine and Sar-
colite are other related unisilicate species.
Nephelite. — Nepheline.
Hexagonal. In hexagonal prisms with replaced basal
edges ; 0Al— 135° 55'. Also massive ; sometimes thin col-
umnar.
Color white, or gray, yellowish, greenish, bluish-red.
Lustre vitreous or greasy. Transparent to opaque. H. =
5-5-6. G. =2 -5-2 -65.
Composition. (Na2, K2)A108Si2= (if Na : K=5 : 1) Sili-
ca 44-2, alumina 33-7, soda 16-9, potash 5-2 = 100; a little
lime is usually present. B.B. fuses quietly to a colorless
glass. Decomposed by hydrochloric acid, and the solution
gelatinizes on evaporation. The name nephelite alludes to
the mineral becoming clouded in acid. Nephelite includes
the glassy crystals from Vesuvius called Sommite, and also
hexagonal crystals in other volcanic rocks ; and a massive
variety, of greasy lustre, called Elceolite, from the Greek
270 DESCRIPTIONS OP MINERALS.
elaion, oil. Altered crystals are in part the mineral Gie-
seckite.
Diff. Distinguished from scapolite and feldspar by the
greasy lustre when massive, and its forming a jelly with
acids ; from apatite by the last character, and also its hard-
ness.
Obs. Nephelite is the prominent constituent of nephelin-
doleryte or nephelinyte, and phonolyte, and occurs also in
some other eruptive rocks ; and it also enters into the con-
stitution of miascyte, zircon-syenyte, metamorphic rocks.
Among the localities are Vesuvius and C. di Bove, in Italy ;
Katzenbuckel, near Heidelberg ; Aussig in Bohemia ; and
as elaeolite, Brevig, Norway ; in Siberia ; in the Ozark
Mountains, Arkansas ; in Litchfield, Maine.
Cancrinite. Crystals like those of nephelite, and compo-
sition similar, except the presence of some carbonates and
usually water. Color white, gray, yellow, green, blue, or
reddish; H. =5-6. G. rr2-4-2;5. On account of the car-
bonates it effervesces in acids. B.B. fuses very easily.
Occurs in crystalline rocks at Miask in the Ural ; in Nor-
way ; Transylvania ; and at Litchfield in Maine, with elaeo-
lite and sodalite. Supposed to be altered nephelite.
Microsommite is near. Sommite (nephelite).
Sodalite.
Isometric. In dodecahedrons ; cleavage dodecahedral.
Color brown, gray, or blue. H. =6. G. =2 -25-2 -3.
Composition. Na2 Al 08 Si2 + J NaCl=Silica 37*1, alumina
31-7, soda 19-2, sodium 4-7, chlorine 7 -3 = 100. B.B. fuses
with intumescence to a colorless glass. Decomposed by hy-
drochloric acid, and the solution gelatinizes on evaporation.
Occurs in eruptive and metamorphic rocks. Found in Si-
cily ; near Lake Laach ; at Miask ; in Norway ; West Green-
land ; of a blue color at Litchfield, Me. ; and lavender-blue
at Salem, Mass.
Hauynite (or Hauyne) and Nosite (or Nosean) are related minerals
from, lavas or other eruptive rocks ; and Ittnerite is altered haiiynite
or nosite. Isometric. In dodecahedrons. Color bright blue, occasion-
ally greenish. Transparent to translucent. H.=6. G.=2'4-25.
Lapis-Lazuli. — Ultramarine.
Isometric. In dodecahedrons; cleavage imperfect. Usual-
ly massive, Color rich Berlin or azure blue. Lustre vitre-
ous. Translucent to opaque. H.=5'5. G. =243-2-5.
UNISILICATES. 271
Composition. Silica 45-5, alumina 31-8, soda 9-1, lime
3 '5, iron 0'8, sulphuric acid 5*9, sulphur 0*9, chlorine 0*4,
water 0-1--98-0. B.B. fuses to a white translucent or
opaque glass, and if calcined and reduced to powder loses
its color in acids ; is decomposed with the evolution of
hydrogen sulphide, and the solution gelatinizes on evapora-
tion. The color of the mineral is supposed to be due to
sodium sulphide. The mineral is not homogeneous, but the
exact nature of the ultramarine species at the basis of it is
not yet ascertained.
Obs. Found in syenyte and granular limestone, and is
brought from Persia, China, Siberia, and Bucharia. The
specimens often contain scales of mica and disseminated
pyrites.
The richly - colored lapis -lazuli is highly esteemed for
costly vases, and for inlaid work in ornamental furniture.
It is also used in the manufacture of mosaics. When pow-
dered it constitutes a beautiful and durable blue paint,
called Ultramarine, which has been a costly color. The
discovery of a mode of making an artificial ultramarine,
quite equal to the native, has aiforded a substitute at a com-
paratively cheap rate. This artificial ultramarine consists
of silica 45-6, alumina 23 '3, soda 21-5, potash 1-7, lime
trace, sulphuric acid 3-8, sulphur 1*7, iron 1-1, and chlorine
a small quantity undetermined. It has taken the place in
the arts, entirely, of the native lapis-lazuli.
Zieucite. — Amphigene.
Dimetric. Form very nearly that of the trapezohedron
represented in the figure. Cleavage imper-
fect. Usually in dull glassy crystals, of a
grayish color ; sometimes opaque- white, dis-
seminated through lava. Translucent to
opaque. H.^5'5-6. G.=2'5. Brittle.
Composition. K2 Al 0,2 Si4 — Silica 55*0,
alumina 23-5, potash 21-53=100. B.B. infu-
sible. Moistened with cobalt nitrate and ig-
nited assumes a blue color. Decomposed by hydrochloric
acid, without gelatinizing.
Diff. Distinguished from analcite by its hardness and in-
fusibility.
Obs. In volcanic rocks, and abundant in those of Italy,
272 DESCRIPTIONS OF MINERALS.
especially at Vesuvius, where crystals occur from the size of
a pin's head to a diameter of an inch. Also found in the
Leucite Hills, northwest of Point of Rocks, Wyoming Ter-
ritory.
The name leucite is from the Greek leukos, white.
FELDSPAR GROUP.
I. RELATIONS OF THE SPECIES OF FELDSPAK.
The species of the Feldspar Group are related —
A. In crystallization : (1) the forms heing all oblique ;
(2) the angle of the fundamental rhombic prism /, in each,
nearly 120° ; (3) the other angles differing but little, al-
though part of the species are monoclinic and part tri-
clinic ; and (4) there being two directions of easy cleavage,
one, the most perfect, parallel to the basal plane 0, and the
other parallel to the shorter diagonal section, with the in-
tervening angle either 90° (as in the monoclinic species or-
thoclase and hyalophane), or nearly 90° (as in the triclinic
species).
B. In composition: (1) the only element in the sesquiox-
ide state being aluminum, and those in the protoxide state
either calcium, barium, sodium, or potassium, or two or
three of these bases together; (2) the ratio of 1 atom of R
to 1 of R being constant ; (3) the amount of silica in the
species increasing with the proportion of alkali, being that
of a unisilicate in the pure lime-feldspar, anorthite, that'
of a tersilicate in the soda-feldspar, albit'e, or potash-feldspar,
orthoclase, and so directly proportioned to the alkali, that
the amount in any lime-and-soda feldspar may be deduced
by taking the lime (or calcium) as existing in the state of a
unisilicate, and the soda in that of a tersilicate, and adding
the two together.
Anorthite has the formula CaAl 08 Sis.
Albite " " Na2Al 016 Si6.
The constitution of a species containing Ca and Na» in
the ratio of 1 to 1 for the protoxide portion may be ob-
FELDSPAR GROUP. 273
tained as follows. Adding together the anorthite and albite
formulas, we have CaNa2Al2 024 Si8 ; then dividing by 2, the
formulas becomes £Ca|Na2Al 012 Si4, which expresses the
composition of andesite. With 3 parts of the Ca unisili-
cate, and 1 of the Na2 tersilicate, the composition is that
of labradorite. So it is for other combinations, that is for
other species between anorthite and albite in composition.
The quantivalent ratio for the R, Al, Si, in the several
species of the group, is as follows : V means triclinic in
crystallization, and IV monoclinic.
SYSTEM OP SYSTEM OP
CRY6TAI.L1ZA- KAT10. CRYSTALLIZA-
TION. TION.
Anortliite, 1:3:4 V, Oligoclase, 1:3:9 V.
Labradorite, 1:3:6 V, Albite, 1:3:12 V.
Hyalophane, 1:3:8 IV, Microcline, 1 : 3 : 12 V.
Andesite, 1:3:8 V, Orthoclase, 1 : 3 : 12 IV.
These are the normal ratios ; but there is some variation
from them in the analyses, part of which is variation in
actual composition, and part a result of interlamination or
mixture of two feldspars together. Thus, orthoclase occurs
mixed with microcline, albite, or oligoclase. But while such
mixtures account for the soda found in some analyses of
orthoclase, it does not for that in all, since soda does occur
in many specimens of pure orthoclase, replacing part of the
potash. It is the same with the triclinic feldspar micro-
cline, which has the composition of orthoclase, and may
have the alkali portion all potash or part soda, one analysis
of typical microcline giving only 0-48 of soda. It is, hence,
not safe to calculate the percentage of orthoclase present
in a feldspar from the percentage of potash. Moreover,
potash is present in much albite.
The above ratios show that anorthite has for the ratio
between R + R and Si, 4 : 4, or 1 : 1, as in true unisilicates ;
while in albite and orthoclase, the same ratio is 4 : 12 or
1 : 3, that of a tersilicate, as above stated.
0. In physical characters : the hardness being between 6
274 DESCRIPTIONS OF MINERALS.
and 7; the specific gravity, between 2-44 and 2-75 ; lustre
vitreous, but often pearly on the face of perfect cleavage ;
and each species transparent to subtranslucent.
II. ACIDIC AND BASIC FELDSPAKS.
Oligoclase, albite, and orthoclase are called acidic feld-
spars, because of the large amount of the acidic element,
silicon, in their constitution, analyses giving 60 to 70 per
cent, of silica ; and labradorite and anorthite are called
basic feldspars, the amount of silica being 42 to 55 per
cent. Correspondingly, eruptive, and metamorphic rocks
in which either of the acidic feldspars is a prominent con-
stituent— for example, granite, gneiss, trachyte, true por-
phyry— are called acidic rocks ; while those rocks in which
basic feldspars are constituents — like doleryte, and a large
part of eruptive rocks — are called basic rocks.
III. DISTINCTIONS OF THE TKICLINIC FELDSPAKS.
The triclinic feldspars are distinguished from the mono-
clinic (e. g. orthoclase) by the occurrence of very line stria-
tions on the cleavage surface, sometimes too fine to be seen
without a good pocket-lens. These striations are due to
multiple twinning parallel to the other cleavage face, as ex-
plained on page 57. They are rarely absent from triclinic
feldspar crystals. They are best brought out by transmitted
polarized light, in which a transverse section of the crys-
tal is seen banded with spectrum colors, each band corre-
sponding to one plate of the twin structure.
The triclinic feldspars, andesite excepted, may be dis-
tinguished from one another by an optical method when
the cleavage direction can be made out. For this purpose
a plate is prepared parallel to the plane of easiest cleavage.
In such a plate the multiple twinning is parallel to the other
cleavage plane, or the shorter diagonal. When the plate is
placed on the stage of a polariscope, between crossed Nicol-
prisms, as the stage is revolved, the adjoining bands of color
become dark alternately, and the angle through which the
FELDSPAR GROUP. 275
plate has to be revolved for the change between consecutive
bands varies for different species, it being 54° to 74° for
anorthite, 10° to 14° for labradorite, 4° to 8° for oligoclase,
6J° to 8° for albite, and 30° for microcline. The shorter
diagonal of the crystal bisects this angle, so that the angle
made with this diagonal is 27° to 37° for anorthite, 5° to
7° for labradorite, 2° to 4° for oligoclase, 3£° to 4° for albite,
and 15° for microcline. Obtaining cleavage plates for such
measurements in the case of slices for microscope investiga-
tion, is seldom possible, and when not so, the only certain re-
source for the distinguishing of triclinic feldspars is chemical
analysis. These feldspars have been called plagioclase (from
the Greek words for oblique and fracture), as if all were of
one species. The term is a convenient cover for ignorance.
IV. DISTINCTIONS FROM OTHER MINERALS. When in
crystals, the form is sufficient to determine a feldspar ; so also
the facl^jf two unequal cleavages inclined to one another at
84° to 90°, one of them quite perfect. No fibrous, columnar,
or micaceous varieties are known. They differ from rho-
donite, by the absence of a manganese reaction ; from spodu-
mene, by the absence of a lithia reaction as well as cleavage
angles; from scapolite, by form, the cleavage angles, the
more difficult fusibility ; from nephelite, by form, and also
in difficult fusibility, and not gelatinizing with acids, ex-
cept in the case of anorthite and labradorite, -which fuse
with but little more difficulty than nephelite, and often will
gelatinize.
Anorthite.— Indianite. Lime Feldspar.
Triclinic. Angle between the two cleavage planes 85° 50'
and 94° 10'. Crystals tabular. Also massive granular or
coarse lamellar. Color white, grayish, or reddish.
Composition. CaAl 08 Si2= Silica 43*1, alumina 36-8, lime
20-1^100. B.B. fuses with much difficulty to a colorless
glass ; decomposed by hydrochloric acid, the solution gela-
tinizes on evaporation.
Obs. Occurs in basic eruptive rocks; also in some meta-
276 DESCRIPTIONS OF MINERALS.
morphic rocks. Found in the lava of Vesuvius ; in the
Tyrol ; Faroe Islands, Iceland ; in imbedded crystals in some
doleryte of the Connecticut Valley.
At Hanover, N. H., anorthite crystals occur altered to a silicate
which afforded, in an analysis by Hawes, only 2 '2 of lime, and, in place
of the rest of this ingredient, 711 of potash, 3-77 of soda, 1 10 of iron-
sesquioxide, and 2 '07 of water, with 80 05 of alumina and 52 52 of
silica ; which compound, if the water be made basic, has the ratio
nearly of labradorite, though distinct from that species in the alkalies,
and also in specific gravity, which is 2 "96 or very nearly 3. It has some
relation to zoisite, and to typical saussurite, but is widely different
in constituents and ratio ; it is related also to jadeite. (See page
263.)
Labradorite. — Lime-soda Feldspar. Labrador Feldspar.
Triclinic. Angle between the cleavage planes 93° 20' and
86° 40'. Usually in cleavable massive forms.
Color dark gray, brown, or greenish brown ; also white or
colorless. Often a series of bright chatoyant colors from in-
ternal reflections, especially blue and green, with more or
less of yellow, red, and pearl-gray.
f Composition. |CaJNa2Al 010Sia= Silica 52;9, alumina 30 -3,
lime 12*3, soda 4-5 = 100. Sometimes contains a little potash
in place of the soda. B.B. fuses quite easily to a colorless
glass. Only partially decomposed by hydrochloric acid.
Obs. A constituent of the larger part" of eruptive rocks, as
doleryte, and amphigenyte, and many lavas ; and also of some
metamorphic rocks. Occurs as an ingredient in part of the
Archaean rocks in North America, and was named from its
first discovery in Labrador.
Andesite. Triclinic. Angle between the cleavage planes 87°-88°.
Near labradorite in composition. The formula iCa|Na2A1012 Si4 =
Silica 59-8, alumina 25 5, lime 7'0, soda 7 -7=100-0.
HycdopJiane. Monoclinic, and hence angle between the cleavage
planes 90°. A baryta feldspar ; the formula like that of andesite, ex-
cepting the substitution of Ba for Caand K2 for Na2. It has been found
in the Binnenthal, Switzerland, and at Jakobsberg, Sweden.
A baryta-feldspar, having the ratio of andesite, 1:3:8, has been
described which is tridinic, and approaches oligoclase in optical char-
acters.
Oligoclase.— Soda-lime Feldspar.
Triclinic. Angle between the cleavage planes 93° 50' and
86° 10'. Commonly in cleavable masses. Also massive.
Color usually white, grayish white, grayish green, green-
ish, reddish. Transparent, subtranslucent. H.=6-7. G-.=
2 -5-2 -7.
FELDSPAR GROUP.
277
Composition. JCajNa.,Al 014 Si5= Silica 61-9, alumina 24-1,
lime 5*2,, soda 8*8 = 100. A portion of the soda is usually
replaced by potash. B. B. fuses without difficulty ; not de-
composed by acids.
Obs. It occurs in granite, syenyte, and various meta-
morphic rocks, especially those containing much silica : and
in such case usually associated with orthoclase. Sunstone is
in part oligoclase containing disseminated scales of hematite
giving hright reflection from the interior of the stone. Oc-
curs in Norway. Moonstone is in part a whitish opalescent
variety. Oligoclase occurs at Unionville, Pa.; Haddam,
Conn. ; Mineral Hill, Del. ; Chester, Mass., etc.
Albite.
Triclinic. Angle between the cleavage planes 93° 36',
and 83° 24'. Figures 1 to 6 represent some of its forms ;
2 and 3 are twin crystals. The crystals are usually more or
less thick and tabular. Also massive, with a granular or
lamellar structure. Color white ; occasionally light tints of
bluish white, grayish, reddish and greenish. Transparent
to subtranslucent.
Composition. Na2Al 016Si,j= Silica 68-6, alumina 19*6,
soda 11 -8 =100-0. B.B. fuses to a colorless or white glass,
imparting an intense yellow to the flame. Not acted upon
by acids.
278 DESCRIPTIONS OF MINKRALS.
Cleavelandite is a lamellar variety occurring in wedge-
shaped masses at the Chesterfield albite vein, Mass.
Obs. Albite occurs in some granites and gneiss, and is
most abundant in granite veins. Fine crystals occur at
Middletown and Haddam, Conn., at Goshen, Mass., and
Granville, N. Y. ; Unionville, Delaware County, Penn.
The name albite is from the Latin albus, white.
Microcline.
A potash-i eldspar, very close to the following species in
angles, and also in physical characters, and identical with it
in composition. But it is very slightly triclinic, the angle
between its cleavage planes varying but 16' from 90° ; and
hence its cleavage surface shows usually the fine striations
exhibited with rare exceptions by all the triclinic feldspars.
Colors white, flesh-red, copper-green. The last is what has
been called Amazon-stone ; as heat destroys the color it has
been supposed to be of organic origin.
Occurs in the zircon-syenyte of Norway ; also in the Urals ;
Greenland; Labrador; Leverett, Mass.; Redding, Conn.;
Delaware ; Chester County, Penn. ; White Mountain Notch,
green ; Pike's Peak, Amazon-stone ; Magnet Cove, Ark.
Orthoclase. — Common Feldspar.
Monoclinic ; and hence angle between the cleavage planes
90°. Figures 1 to 4 represent common forms, and 5 to 8
twin crystals. Usually in thick prisms, often rectangular,
and also in modified tables. Also massive, with a granular
structure, or coarse lamellar ; also fine-grained almost flint-
like in compactness. Colors light ; white, gray, and flesh-
red common ; also greenish and bluish-white and green.
Composition. K2 Al 016 Si6 = Silica 64-7, alumina 18-4,
potash 16 '9 =100. Soda sometimes replaces a portion of
the potash. B.B. fuses with difficulty; not acted on by
acids.
Common feldspar includes the common subtranslucent
varieties ; Adularia, the white or colorless subtransparent
specimens, a name derived from Adula, one of the highest
peaks of St. Gothard. Sanidin or glassy feldspar includes
transparent vitreous crystals, found in tradhytes and lavas ;
but some of the "glassy feldspar" belongs to the species
anorthite. Loxodase is a grayish variety with a pearly or
greasy lustre that contains much soda.
FELDSPAR GROUP.
279
Moonstone is an opalescent variety of adularia, having
when polished peculiar pearly reflections. Sunstone is simi-
lar; but contains minute scales of mica. A venturing feld-
spar often owes its iridescence to minute crystals of specular
or titanic iron, or limonite. Sunstone and moonstone are
mostly oligoclase, and so is a large part of aventurine feld-
spar.
Diff. Distinguished from the other feldspars by its right-
angled cleavage and the absence of striated surfaces.
Obs. Orfchoclase is one of the constituents of granite, sye-
nyte, gneiss, and other related rocks ; also of porphyry, and
trachyte ; and it often occurs in these rocks in imbedded
crystals. St. Lawrence County, N. Y., affords fine crystals ;
also Orange County, N. Y. ; Haddam and Middletown,
Conn.; Acworth, N. H. ; South Royalston and Barre,
Mass., besides numerous other localities. Green feldspar
occurs at Mount Desert, Me.; an aventurine feldspar at
Leiperville, Penn. ; adularia at Haddam and Norwich,
Conn., and Parsonsfield, Me. A fetid feldspar (sometimes
called necronite) is found at Koger's Rock, Essex County ;
at Thomson's quarry, near 196th Street, New York City,
and 21 miles from Baltimore. Carlsbad and Elbogen in Bo-
hemia, Baveno in Piedmont, St. Gothard, Arendal in Nor-
way, Land's End, and the Mourne Mountains, Ireland, are
some of the more interesting foreign localities.
280 DESCRIPTIONS OF MINERALS.
Felsite is compact, uncleavable orthoclase, having the
texture of jasper or flint, which it much resembles. It often
contains some disseminated silica. It occurs of various col-
ors, as white, gray, brown, red, brownish red and black, and
is sometimes banded. It is distinguished from flint or jas-
per by its fusibility.
Felsite is the material of beds or strata in some rock for-
mations, and also of dikes or masses of eruptive rocks. It is
the base of much red porphyry. The vicinity of Marblehead,
Mass., is one of its localities.
The name feldspar is from the German word Feld, mean-
ing field. It is, therefore, wrong to write it felspar.
Orthoclase is used extensively in the manufacture of por-
celain. The large granite veins of Middletown and Port-
land, Conn., are quarried in several places for both orthoclase
and quartz for this purpose ; the places are often called
China-stone quarries.
Kaolin. This name is applied to the clay that results
from the decomposition of feldspar. See Kaolinite, p. 310.
m. SUBSILICATES.
In the Subsilicates, as stated on page 242, the combin-
ing or quantivalent ratio between the bases and silica is 1
to less than 1. In Chondrodite, the first of the following
species, the ratio is 4:3; in Tourmaline, Andalusite, Cya-
nite, and Fibrolite, 3 : 2. Analyses of Andalusite obtain 1
of alumina, Al 03, to 1 of silica, Si 02, giving the oxygen
ratio for bases and silica 3 : 2. This is the composition also
of cyanite and fibrolite ; so that the three species, anda-
lusite, cyanite, and fibrolite are the same in constituents
and atomic ratio while differing in crystalline form, exem-
plifying a case of trimorphism among minerals.
The ratio 3 : 2 exists also in Topaz, Euclase and Da-
tolite in Titanite or sphene, and in Keilhauite. In Stau-
rolite, the ratio was formerly regarded as 2:1; but the
most recent analyses, those of Eammelsberg, give 11 : 6, or
1$:1. . In datolite and tourmaline the basic constituents
include boron ; in titanite and keilhauite, titanium ; in da-
8UBSILICATES. 281
tolite, euclase, and part of staurolite, hydrogen, that is, the
hydrogen of the water found on analysis. In chondrodite,
topaz, and some tourmaline, fluorine replaces part of the
oxygen.
Chondrodite. — Humite in part (Scacchi's Type II).
Monoclinic. Cleavage indistinct. Usually in imbedded
grains or masses. Color light yellow to brownish yellow, yel-
lowish red, and garnet-red. Lustre vitreous, inclining a little
to resinous. Streak white, or slightly yellowish or grayish.
Translucent or subtranslucent. Fracture uneven. H/=6-
6-5. G.=3-l-3-25.
Composition. Mgs 0,4 Si3 ; but a portion of the magnesium
replaced by iron, and a part of the oxygen by fluorine. A
specimen from Brewster's, New York, afforded Silica 34'1,
magnesia 53-7, iron protoxide 7*3, fluorine 4-2, with 0-48 of
alumina =99*72.
B.B. infusible. Decomposed by hydrochloric acid ; the
solution gelatinizes on evaporation.
Diff. As it cccurs only in limestone it will hardly be con-
founded with any species resembling it in color when the
gangue is present. It does not fuse lil^e, tourmaline or gar-
net, some brownish-yellow varieties of which it approaches
in appearance. The name is from the Greek chondros, a
grain.
Obs. It is abundant in the adjoining counties, Sussex, N. J.,
and Orange, N. Y., occurring at Sparta and Bryam, N. J.,
and in Warwick and other places in N. Y. ; at the Tilly
Foster Iron Mine, Brewster's, Putnam County, N..Y., it is
very abundant. At Vesuvius it occurs in small crystals.
The species was early named Chondrodite, from Finland
specimens ; soon afterward small crystals, found in the lavas
of Somma (Vesuvius), were named Humite, and both were
referred to the same species. It has recently been ascer-
tained that under this species, two species of different an-
gles and form, but related composition and physical charac-
ter, are included. For these species the names Humite and
Clinohumite have been adopted.
Humite is orthorhombic, and embraces part of the Humite
crystals of Vesuvius (Scacchi's Type I.), and some large
coarse chondrodite-like crystals found at Brewster's, N. Y.
Clinohumite is monoclinic, and includes Scacchi's Type III.
282
DESCRIPTIONS OF MINERALS.
of Humite from Vesuvius, and fine chondrodite-like crystals
from Brewster's.
Tourmaline.
Rhombohedral. Usual in prisms of 3, 6, 9, or 12 sides,
terminating in a low 3-sided pyramid. The sides of the
prisms are often rounded and striated. Other forms are
shown in the figures. The common pyramid is the rhoinbo-
1.
2.
hedron — J in the figures, the angle of which is 133° 8'. The
crystals often have unlike secondary planes at the two ex-
tremities, as shown in figure 3. Occurs also compact mas-
sive, and coarse columnar, the columns sometimes radiating
or divergent from a centre.
Color black, blue-black, and dark brown, common ; also
bright and pale red, grass-green, cinnamon-brown, yellow,
gray, and white. Sometimes red within and green externally,
or one color at one extremity and another at the other.
Transparent ; usually translucent to nearly opaque. Di-
chroic. Lustre vitreous, inclining to resinous on a surface
of fracture. Streak uncolored. Brittle ; the crystals often
fractured across and breaking very easily. H.= 7*0-7 *5. G.
= 3-33.
Composition. (R3,B2,R,) 05, Si2, in which R includes, in
different varieties, Fe, Mg, Na2, with often traces also of Ca,
Mn, K2, Li2; R includes aluminum, with some boron in the
trioxide state replacing =41 ; and a little of the oxygen is
sometimes replaced by fluorine.
A black tourmaline from Haddam afforded on analysis,
Silica 37-50, boron trioxide (by loss) 9-02, alumina 30-87,
iron protoxide 8 '54, magnesia 8 -60, lime 1-33, soda 1-60,
potash 0 -73, water 1 -81 = 100. A red tourmaline from Paris,
Maine, afforded Fluorine 1-19, silica 41-16, boron trioxide
(by loss) 8-93, alumina 41-83, manganese protoxide 0-95,
magnesia 0-61, soda 1 '37, potash 217, lithia 0-41, water 2-57
=100.
Tourmaline varies much in color owing to its variations in
SUBSILICATES. 283
composition ; the dark contain much iron and the light
colors but little. Some of the varieties have received special
names. Rubellite is red tourmaline; and Indicolite, Hue and
bluish-black. Schorl formerly included the common black
tourmaline, but the name is not now used.
The presence of boron trioxide is the most remarkable
point in the constitution of this mineral. The colorless, red,
and pale-greenish kinds usually contain lithia. B.B. the
darker varieties fuse with ease, and the lighter with difficulty.
On mixing the powdered mineral with potassium bisulphate
and fluor spar, and heating B.B. , gives a green flame owing
to the boron.
Diff. The black and the dark varieties generally, are
readily distinguished by the form and lustre and absence of
distinct cleavage, together with their difficult fusibility.
The black when fractured often appear a little like a black
resin. The brown variety resembles garnet or idocrase, but
is more infusible. The red, green, and yellow varieties are
distinguished from any species they resemble by the crystal-
line form, the prisms of tourmaline always having 3, 6, 9,
or 12 prismatic sides (or some multiple of 3). The electric
properties of the crystals, when heated, is another remarka-
ble character of this mineral. The test for boron is always
good.
Obs. Tourmalines are common in granite, gneiss, mica
schist, chlorite schist, steatite, and granular limestone.
They usually occur penetrating the rock. The black crys-
tals are often highly polished and at times a foot in length,
when perhaps of no larger dimensions than a pipe-stem, or
even more slender. This mineral has also been observed in
sandstones near basaltic or trap dikes.
Red and green tourmalines, over an inch in diameter and
transparent, have been obtained at Paris and Hebron, Me.,
besides pink and blue crystals. These several varieties oc-
cur also, of less beauty, at Chesterfield and Goshen, Mass.
Good black tourmalines are found at Norwich, New Brain-
tree, and Carlisle, Mass. ; Alsted, Acworth, and Saddleback
Mountain, N. H. ; Haddam and Monroe, Conn. ; Sara-
toga and Edenville, N. Y. ;- Franklin and Newton, N. J.;
near Union ville, Chester, and Middletown, Penn. ; trans-
parent brown at Hunterstown, Canada East ; amber-colored
at Fitzroy ; black at Bathurst, and Elmsley, Canada West ;
fine greenish yellow at G. Calumet I.
284 DESCRIPTIONS OP MINERALS.
Dark brown tourmalines are obtained at Orford, N. H.;
in thin black crystals in mica at Grafton, N. H. ; Monroe,
Ct. ; Gouverneur and Amity, N. Y. ; Franklin and Newton,
N. J. A fine cinnamon-brown variety occurs at Kings-
bridge and Amity, Orange Co., N. Y. and also south in New
Jersey. A gray or bluish-gray and green variety occurs near
Edenville.
The word tourmaline is a corruption of the name used in
Ceylon, whence it was first brought to Europe. Lyncurium
is supposed to be the ancient name for common tourmaline ;
and the red variety was probably called hyacinth.
The red tourmalines, when transparent and free from
cracks, such as have been obtained at Paris, Me., are of great
value and afford gems of remarkable beauty. They have
all the richness of color and lustre belonging to the ruby,
though measuring an inch across. The yellow tourmaline,
from Ceylon is but little inferior to the' real topaz, and is
often sold for that gem. The green specimens, when clear
and fine, are also valuable for gems. Plates from pellucid
crystals cut in the direction of a vertical plane are much
used for polariscopes.
Gehlenite. Tetragonal, like the scapolites, and grayish green in
color. G. =2 -9-3 '07. Formula Ca3AlO)0Si, with some of the Al re-
placed by J"e, and some of the Ca by Fe and Mg. From Mount
Monzoni in the Fassa Valley.
Andalusite.
Trimetric. In rhombic prisms, which are nearly square ;
/A/=90° 48'. Cleavage lateral; sometimes distinct. Also
massive and indistinctly coarse columnar, but never fine
fibrous.
Colors gray and flesh-red. Lustre vitreous, or inclining to
pearly. Translucent to opaque. Tough. H. — 7*5. G. =
3-1-3-3.
1. 2. 3. 4.
Composition. A105 Si = Silica 36-9, alumina 63-1 = 100.
B.B. infusible. Ignited after being moistened with cobalt
nitrate assumes a blue color. Insoluble in acids.
SUBSILICATES. 285
CMastolite and made are names given to crystals of anda-
lusite which show a tessellated or cruciform structure when
broken across and polished. The above figures represent
sections of crystals from Lancaster, Mass. The structure is
owing to carbonaceous impurities distributed in the crystal-
lizing process in a regular manner along the sides, edges
and diagonals of the crystal. Their hardness is sometimes
as low as 3.
Diff. Distinguished from pyroxene, scapolite, spodumene,
and i'eldspar, by its infusibility, hardness, and form.
Obs. Most abundant in clay slate and mica slate, but oc-
curring also in gneiss. Found in the Tyrol, Saxony, Bavaria,
etc. ; also in Westford, Mass. ; Litchfield and Washington,
Ct. ; Bangor, Me. ; Leiperville, Marple, and Springfield,
Penn. ; and chiastolite at Sterling and Lancaster, Mass.,
and near Bellows Falls, Vermont. This species was first
found at Andalusia in Spain.
Pibrolite. — Sillimanite. Bucholzite.
Orthorhombic. In long, slender rhombic prisms, often
much flattened, penetrating the gangue. /A/=96°-98°.
A brilliant and easy cleavage, parallel to the longer diago-
nal. Also in masses, consisting of aggregated crystals or
fibres. Color hair-brown or grayish brown. Lustre vitre-
ous, inclining to pearly. Translucent crystals break easily.
H.=G-7. G.=3-2-3-3.
Composition. A105Si, as for andalusite, = Silica 36*9, alu-
mina 63-1=: 100. Moistened with cobalt nitrate and ig-
nited assumes a blue color. Infusible alone and with borax.
Diff. Distinguished from tremolite and the varieties gen-
erally of hornblende by its brilliant diagonal cleavage, and
its infusibility ; from kyanite and andalusite by its brilliant
cleavage, its fibrous structure, and its rhombic crystalline
form.
Obs. Found in gneiss, mica schist, and related metamor-
phic rocks. Occurs in the Tyrol, at Bodenmais in Bavaria ;
at the White Mountain Notch in N. H.; at Chester and
near Norwich, Conn. ; Yorktown, N. Y. ; Chester, Bir-
mingham, Concord, Darby, Penn. ; in North Carolina ; and
elsewhere. Fibrolite was much used for stone implements
in Western Europe in the " Stone age ; " the locality whence
the material was derived is not known.
286 DESCRIPTIONS OF MINERALS.
Cyanite.— Kyanite. Disthene.
Triclinic. Usually in long thin-bladed crystals aggre-
gated together, or penetrating the gangue. Sometimes in
short and stout crystals. Lateral cleavage distinct. Some-
times fine fibrous.
Color usually light blue, sometimes having a blue centre
with a white margin; sometimes white, gray, green, or even
black. Lustre of flat face a little pearly. H. =5-7*5, greatest
at the ends of the prisms, and least on the flat face of the
prism. G. =3-45-3-7.
Composition. A105Si, as for andalusite, = Silica 36-9,
alumina 63 '1 = 100. Blowpipe characters like those of an-
dalusite.
Diff. Distinguished by its infusibility from varieties of
the hornblende family. The short crystals have some re-
semblance to staurolite, but their sides and terminations are
usually irregular ; they differ also in their cleavage and
lustre. The thin-bladed habit of cyanite is very character-
istic.
Obs. Found in gneiss and mica schist, and of ten accom-
panied by garnet and staurolite.
Occurs in long-bladed crystallizations at Chesterfield and
Worthington, Mass. ; at Litchfield and Washington, Conn. ;
near Philadelphia ; near Wilmington, Delaware ; and in
Buckingham and Spotsylvania counties, Va. Short crystals
(sometimes called improperly fibrolite) occur in gneiss at
Bellows Falls, Vt., and at Westfield and Lancaster, Mass.
In Europe, at St. Gothard in Switzerland, at Greiner and
Pfitsch in the Tyrol, in Styria, Carinthia, and Bohemia.
Villa Rica in South America affords fine specimens.
The name cyanite is from the Greek Jcuanos, a dark-blue
substance. It is also called disthene, in allusion to the un-
equal hardness in different directions, and when white, rlice-
tizite.
Kyanite is sometimes used as a gem, and has some resem-
blance to sapphire.
Topaz.
Trimetric. /A I— 124° 17'. Rhombic prisms, usually dif-
ferently modified at the two extremities. /A/= 124° 17'.
Cleavage perfect parallel to the base.
Color pale yellow ; sometimes white, greenish, bluish, or
8UBSILICATES.
287
reddish. Streak white. Lustre vitreous. Transparent to
subtranslucent. Pyro-electric. H. = 8. G= 3-4-3-65.
Composition. Al 05 Si, with a part of the oxygen replaced
by fluorine = Silica 16*2, silicon fluorid 28-1, alumina 55 '7
1.
2.
= 100. An analysis of one specimen afforded, Silica 34'24,
alumina 57 '45, fluorine 14-99. 13. B. infusible. Some kinds
become yellow or of a pink tint when heated. Moistened
with cobalt nitrate and ignited assumes a fine blue color.
Insoluble in acids.
Diff. Topaz is readily distinguished from tourmaline and
other minerals it resembles by its brilliant and easy basal
cleavage.
Obs. Pycnite is a variety presenting a thin columnar struc-
ture and forming masses imbedded in quartz. The PJiysalite
or Pyrophysalite of Hisinger is a coarse, nearly opaque va-
riety, found in yellowish-white crystals of considerable di-
mensions. This variety intumesces when heated, and hence
its name from phusao, to blow, and pur, fire.
Topaz is confined to metamorphic rocks or to veins inter-
secting them, and is often associated with tourmaline, beryl,
and occasionally with apatite, fluorite, and tin ore.
Fine topazes are brought from the Uralian and Altai
mountains, Siberia, and from Kamschatka, where they occur
of green and blue colors. In Brazil they are found of a deep
yellow color, either in veins or nests in lithomarge, or in
loose crystals or pebbles. Magnificent crystals of a sky-blue
color have been obtained in the district of Cairngorm, in
Aberdeenshire. The tin mines of Schlackenwald, Zinnwald,
and Ehrenfriedersdorf in Bohemia, St. Michael's Mount in
Cornwall, etc., afford smaller crystals. The physalite va-
riety occurs in crystals of immense size at Finbo, Sweden,
in a granite quarry, and at Broddbo. A well-defined crys-
tal from this locality, in the possession of the College of
Mines of Stockholm, weighs eighty pounds. Altenberg in
288 DESCRIPTIONS OF MINERALS.
Saxony, is the principal locality of pycnite. It is there as-
sociated with quartz and mica.
Trumbull, Conn., is a prominent locality of this species
in the United States. It seldom affords fine transparent
crystals, except of a small size ; these are usually white, oc-
casionally with a tinge of green or yellow. The large coarse
crystals sometimes attain a diameter of several inches (rare-
ly six or seven), but they are deficient in lustre, usually of
a dull yellow color, though occasionally white, and often
are nearly opaque. It is found also at Crowder's Mountain
in N. 0. ; in Utah, in Thomas's Mountains, and in gold
washings in Oregon.
The ancient topazion was found on an island in the Red
Sea, which was often surrounded with fog, and therefore
difficult to find. It was hence named from topazo, to seek.
This name, like most of the mineralogical terms of the an-
cients, was applied to several distinct species. Pliny describes
a statue of Arsinoe, the wife of Ptolemy Philadelphus, four
cubits high, which was made of topazion, or topaz, but evi-
dently not the topaz of the present day, nor chrysolite,
which has been supposed to be the ancient topaz. It has
been conjectured that it was a jasper or agate ; others have
supposed it to be prase or chrysoprase. '
Topaz is employed in jewelry, and for this purpose its
color is often altered by heat. The variety from Brazil as-
sumes a pink or red hue, so nearly resembling the Balas
ruby, that it can only be distinguished by the facility with
which it becomes electric by friction. Beautiful crystals
for the lapidary are brought from Minas Novas, in Brazil.
"When cut with facets and set in rings, they are readily mis-
taken, if viewed by daylight, for diamonds. From their
peculiar limpidity, topaz pebbles are sometimes denomi-
nated gouttes d'eau.
The perfect cleavage of topaz makes it a poor substitute
for emery.
Euclase.
Monoclinic. In oblique rhombic prisms, with cleavage
highly perfect parallel to the clinodiagonal section, afford-
ing smooth polished faces.
Color pale green to white or colorless, pale blue. Lustre
vitreous; transparent. Brittle. H.^7'5. G. =3'1. Pyro-
electric.
SUBSILICATES. 289
Composition. H2Be2Al 0,0 Si2= Silica 41-20, alumina 35 *^2,
glucina 17-39, water 6-19= 100. B.B. fuses with much dif-
ficulty to a white enamel ; not acted on by acids.
Diff. The cleavage of this glassy mineral is, like that of
topaz, very perfect, but is not basal. The cleavage distin-
guishes it from tourmaline and beryl.
Obs. Occurs in the Ural, and with topaz in Brazil.
The crystals of this mineral are elegant gems of them-
selves, but they are seldom cut for jewelry on account of
their brittleness.
Datolite.— Datholite. Humboldtite.
Monoclinic. Crystals without distinct cleavage ; small
and glassy. Also botryoidal,
with a columnar structure,
and then called botryolite.
Color white, occasionally gray-
ish, greenish, yellowish, or red-
dish. Translucent. H.= 5-5*5.
Composition. H2Ca2B2 010 Si«
= Silica 37*5, boron trioxide
21-9, lime 35 -0, water 5 "6=
100. Botryolite contains twice
the proportion of water. B. B.
becomes opaque, intumesces and melts easily to a glassy
globule coloring the flame green. Decomposed by hydro-
chloric acid ; the solution gelatinizes on evaporation.
Diff. Its glassy complex crystallizations, without cleavage,
are unlike any other mineral that gelatinizes with acid.
It is distinguished from minerals that it resembles also by
tingeing the blowpipe-flame green.
Obs. Occurs in cavities in trap rocks and gneiss. Found
in Scotland ; at Andreasburg ; at Baveno ; Toggiana ; also
Bergen Hill, in N. J. ; in Connecticut, at Eoaring Brook,
14 miles from New Haven ; and near Hartford, Berlin, Mid-
dlefield Falls, Conn. ; also in great abundance at Eagle
Harbor in the copper region, Lake Superior, and on Islo
Royale ; also near Santa Clara, Cal.
Homilite. A black silicate of iron and calcium, resembling gadoli-
nite, but affording from 15 to 18 per cent, of boracic acid with 32 of
silica ; formula R8B2 O)0 Si2. From Brevig, Norway.
290 DESCRIPTIONS OF MINERALS.
Titanite. — Sphene.
Monoclinic. In very oblique rhombic prisms ; the lateral
faces making angles often of 76° 7', 113° 31' (/A/), 136° 12'
1. 2.
(2 A 2), or 133° 52V The crystals are usually thin with
sharp edges. Cleavage in one direction sometimes perfect.
Occasionally massive. •»
Color grayish-brown, ash-gray, brown to black; some-
times pale yellow to green ; streak uncolored. Lustre
adamantine to resinous. Transparent to opaque. H. = 5-
5-5. G. =3 '2-3 -6.
Composition. CaTi05 Si = Silica 30-6, titanium dioxide
40 '82, lime 28'57 — 100 ; in dark brown and black crystals,
some iron replaces part of the calcium. B.B. fuses with
intumescence. Imperfectly decomposed by hydrochloric
acid.
The dark varieties of this species were formerly called
titanite, and the lighter sphene. The name sphene alludes
to the wedge-shaped crystals, and is from the Greek sphen,
wedge. Greenovite is a variety colored rose-red by manga-
nese.
Dtff. The thin wedge-like form of the crystals, in general,
readily distinguish this species ; but some crystals are very
complex.
Obs. Sphene occurs mostly in disseminated crystals in
franite, gneiss, mica slate, syenyte, or granular limestone,
t is usually associated with pyroxene and scapolite, and
often with graphite. It has been found in volcanic rocks.
The crystals are commonly J to J an inch long ; but are
eometimes 2 or more inches in length.
Foreign localities are Arendal in Norway ; at St. Gothard
and Mont Blanc ; in Argyleshire and Galloway in Great
Britain. Occurs in Canada, at Grenville and elsewhere ;
New York, at Roger's Rock, on Lake George ; with graphite
SUBSILICATES. 291
and pyroxene, at Gouverneur, near Natural Bridge in Lewis
County (the variety called Lederite); in Orange County in
Monroe, Edenville, Warwick, and Amity ; near Peekskill in
Westchester County, and near West Farms ; in Massachu-
setts, at Lee, Bolton, and Pelham ; in Connecticut, at Trum-
bull ; in Maine, at Sanford, and Thomaston ; in New Jer-
sey, at Franklin ; in Pennsylvania, near Attleboro', Bucks
County ; in Delaware, at Dixon's quarry, 7 miles from
Wilmington ; in Maryland, 25 miles from Baltimore, on
the Gunpowder.
Ouarinite. Like sphene in composition, but trimetric.
Keilhauite, or Tttro-titanite. Related to sphene. Brownish-black,
with a grayish-brown powder. G. =3*69. H. =6*5. Fuses easily.
Affords Silica 30 '0, titanic acid 29 0, yttria 9' 6, lime 18 '9, iron sesqui-
oxide 6*4, alumina 6*1. From Arendal, Norway.
Tscheffkinite. Near Keilhauite. From the llmen Mountains.
«
Staurolite. — Staurotide.
Trimetric. /A 7=129° 20'. Cleavage imperfect. Usual-
ly in cruciform twin crystals. Fig- 2.
ure 2 is a common kind ; another
crosses at an acute angle near 60° ;
and another, of rare occurrence, con-
sists of three crystals intersecting at
angles near 60°. Never in massive
forms or slender crystallizations.
Color dark brown or black. Lustre vitreous, inclining
to resinous ; sometimes bright, but often dull. Translu-
cent to opaque. H.=7-7'5. G.=3'4-3'8.
Composition. H2R3A16 O34 Si6= Silica 30*37, alumina 51*92,
iron protoxide 13'66, magnesia 2-53, water 1*52=100. B.B.
infusible. Insoluble in acids.
Diff. Distinguished from tourmaline and garnet by its
infusibility and form.
Obs. Found in mica slate and gneiss, in imbedded crys-
tals.
Occurs very abundant through the mica schist of New
England : Franconia, Vt. ; Windham, Me. ; Lisbon, N. H. ;
Chesterfield, Mass ; Bolton and Tolland, Ct. ; also on the
Wichichon, eight miles from Philadelphia ; at Canton, and
in Fannin County, Georgia. Mt. Campione in Switzerland,
and the Greiner Mountain, Tyrol, are noted foreign locali-
ties.
DESCRIPTIONS OF MINERALS.
The name staurolite is from the Greek stauros, a cross.
Schorlomite. Black, and often irised tarnished. Streak grayish-black.
H. =7-7 '5. G. =380. Fuses readily on charcoal. Easily d'ecomposed
by the acids, and gelatinizes. Contains much titanium, with iron, lime,
and silica. From Magnet Cove, Arkansas, and Kaiserstuhlgebirge,
Breisgau.
B. HYDROUS SILICATES.
The three sections under which the Hydrous Silicates
are arranged are the following :
I. GENERAL SECTION. Under this section there are in-
cluded : (1) Bisilicates — Pectolite, Laumontite, Apophy-
lite, etc. ; (2) Unisilicates — Prehnite, Calamine, etc. ; and
(3) Subsilicates — as Allophane, and some related species.
II. ZEOLITE SECTION. The minerals included are feld-
spar-like in constituents, and apparently so in quantivalent
(or oxygen) ratio ; the basic elements being, as in the feld-
spars, (1) aluminum, and (2) the metals of the alkalis K,
Na, and of the alkaline earths Ca, Ba, with also Sr, to the
almost total exclusion of magnesium and iron.
III. MARGAROPHYLLITE SECTION. This section em-
braces species having a micaceous or thin-foliated struc-
ture when crystallized, with the surface of the folia pearly,
and the plane angle of the base of the prism 120°. Whether
crystallized or massive the feel is greasy, at least when
pulverized. It comprises (1) Bisilicates : including Talc and
Pyrophyllite, which are atomically and physically similar
species, although the former is a magnesium silicate, and
the latter an aluminum silicate ; (2) Non-alkaline Uni-
silicates, including Kaolinite and Serpentine, which have a
similar difference in constituents to the preceding with
the same likeness in composition, and also some related
species ; (3) Alkaline Unisilicates : as, Finite and the Hy-
drous Micas, which are species containing potassium or
sodium as an essential constituent; (4) the Chlorite Group,
the species of which arc mostly Subsilicates.
HYDROUS SILICATES — GENERAL SECTION. 293
I. GENERAL SECTION,
Pectolite.
Monoclinic, isomorphous with wollastonite. Usually in
aggregations of acicular crystals, or fibrous-massive, radiate,
stellate. Color white, or grayish. Translucent to opaque.
Tough. H.=5. G. =2-68-2 -8.
Composition. R 03 Si, in which R=r£H2 -J-Na2 fCa, = Silica
54-2, lime 33*8, soda 9-3, water 2'7=100. In the closed
tube yields water. B. B. easily fusible. Decomposed by hydro-
chloric acid, and the solution gelatinizes somewhat when
evaporated.
i>iff. Its fibrous forms and its blowpipe reactions are
distinctive.
Obs. Occurs mostly in cavities or seams in trap or basic
eruptive rocks, and occasionally in other rocks. Found
at Ratho Quarry, near Edinburgh, Scotland ; at Kilsyth ;
Isle of Skye ; in the Tyrol ; in fine specimens at Bergen
Hill, N. J. ; a compact variety at Isle Royale, Lake Supe-
rior.
Okenite and Gyrolite are related hydrous calcium silicates. Okenite
is from the Faroe Islands, Iceland, and Greenland, and gyrolite from
the Isle of Skye, and from Nova Scotia 25 miles southwest of Cape
Blomidon.
Liaumontite.
Monoclinic, with the angles nearly of pyroxene ; /A /=
86° 16'. Cleavage parallel to the clinodiagonal section and
to / perfect. Also massive, with a radiating or divergent
structure.
Color white, passing into yellow or gray, sometimes red.
Lustre vitreous, inclining to pearly on the cleavage face.
Transparent to translucent. H. = 3'5-4. G.=2'25-2'36.
Becomes opaque on exposure through loss of water, and
readily crumbles.
Composition. CaAl 0,5Si4 + 4 aq= Silica 50'0, alumina
21-8, lime 11-9, water 16-3 = 100. B.B. swells up and fuses
easily to a white enamel. Decomposed by hydrochloric acid,
and the solution gelatinizes on evaporation.
Diff. The alteration this species undergoes on exposure
to the air at once distinguishes it. This result may be
prevented with cabinet specimens, by dipping them into a
solution of gum arabic.
294
DESCRIPTIONS OF MINERALS.
Otis. Found in the veins and cavities of trap rocks and
also in gneiss, porphyry. Occurs at the Faroe Islands ; Kil-
patrick Hills, near Glasgow ; Disco, Greenland ; St. Groth-
ard, Switzerland ; Peter's Point, Nova Scotia ; Phippsburg,
Me.; Charlestown syenite quarries, Mass. ; Bergen Hill,
N. J. ; the Copper region, Lake Superior, and Isle Royale.
Leonhardite. Probably Laumontite which has lost part of its water
by alteration. It resembles that species in crystallization and in most
of \ts characters, but differs in being less efflorescent on exposure to a
dry atmosphere. Analyses of specimens from Copper Falls, Lake
Superior, have obtained, Silica 55'50, alumina 2.1 '19, lime 10'5G, water
11*93 = 99-68. The Copper Falls variety alters little on exposure.
Reported also from trachyte at Schemnitz, in Hungary, and from Pfitsch
in the Tyrol
Apophyfflte.
Dimetric. In square octahedrons, prisms, and tables.
Cleavage parallel with the base highly perfect. Massive
1.
3.
and foliated. Color white or grayish ; sometimes with a
shade of green, yellow, or red. Lustre of O pearly : of the
other faces vitreous. Transparent to opaque. H.=4*5— 5.
G. =2 -3-2-4.
Composition. A silicate of calcium and hydrogen com-
bined, with potassium fluoride and water, of the formula
(JH2£Ca) 03Si + £KF+iaq = Silica 52'97, lime 24-^2,
potash 5-20, water 15 '90, fluorine 2-10=100-89. B.B. exfo-
liates, colors the flame violet (owing to the potash), and
fuses very easily to a white enamel. In the closed tube
yields water which has an acid reaction. Decomposed by
hydrochloric acid with the separation of slimy silica.
HYDROUS SILICATES — GENERAL SECTION. 295
Diff. The pearly basal cleavage and the forms of its glassy
crystals at once distinguish it from the preceding species.
The prisms are sometimes almost cubes, with the angles
cut oif by the planes of the pyramid ; but the difference in
the lustre of the prismatic and basal faces shows that it
is dimetric.
The name alludes to its exfoliation before the blowpipe.
Obs. Found in amygdaloidal trap and basalt.
Occurs in fine crystallizations at Peter's Point and Par-
tridge Island, Nova Scotia, at Bergen Hill, N. J., the Cliff
Mine, Lake Superior region.
Catapleiite. A hydrous zirconium and sodium silicate, from Nor-
way.
Dioptase and Chrysocolla. Hydrous copper silicates. See p. 141.
Picrosmine, Pyrallolite, Picropliyll, Traversellite, Pitkaraiulite, Stra-
konitzite, Monradite, are names of varieties of pyroxene in different
stages of alteration. Xylotine is probably altered asbestus.
Frehnite.
Trimetric. /A 7=99° 56'. Cleavage basal. Sometimes
in six-sided prisms, rounded so as to be barrel-shaped, and
composed of a series of united plates ; also in thin rhom-
bic or hexagonal plates. Usually reniform and botryoidal,
with a crystalline surface ; texture compact.
Color light green to colorless. Lustre vitreous, except
the face 0, which is somewhat pearly. Subtransparent to
translucent. H. = 6-6-5. G. =2-8-2 '96.
Composition. H2Ca2A10i2 Si3= Silica 43-6, alumina 24*9,
lime 27'1, water 4-4=100. B.B. fuses very easily to an en-
amel-like glass. Decomposed by hydrochloric acid, leaving
a residue of silica in light flakes, but the solution does not
gelatinize. Yields a little water when heated in a closed
tube.
Diff. Distinguished from beryl, green quartz, and chal-
cedony by fusing before the blowpipe, and from the zeolites
by its superior hardness.
Obs. Found in the cavities of trap, gneiss, and granite.
Occurs in the trap rocks of the Connecticut Valley, and
at Paterson and Bergen Hill, N. J. ; in gneiss at Bellows
Falls, Vt. ; in syenyte at Charlestown, Mass. ; and very
abundant, forming large veins, in the Copper region of Lake
Superior, three miles south of Cat Harbor, and elsewhere.
The Fassa Valley in the Tyrol, St. Christophe in Dau-
296 DESCRIPTIONS OP MINERALS.
phiny, and the Salisbury Crag, near Edinburgh, are some
of the foreign localities.
Prehnite receives a handsome polish and is sometimes
used for inlaid work. In China it is polished for orna-
ments, and large slabs have been cut from masses brought
from there.
Clilorastrolitc and Zonochlorite, from the Lake Superior region, are
impure prehnite.
Chalcomorphite. A hydrous calcium silicate, from calcite in cavities
of lava, containing but 25 "4 per cent, of silica.
Gismondite (Zeagonite). A hydrous lime-aluminum silicate, occur-
ring in trimetric crystals resembling square octahedrons ; found in
lava at Capo di Bove, near Rome.
Edingtonite. A hydrous barium-aluminum silicate. Occurring in
crystals and massive. From the Kilpatrick Hills, with harmotome.
Carpholite. A manganese- aluminum silicate, occurring in silky,
yellow, radiated tufts. From the tin mines of Schlackenwald.
PyrosmaMte. A manganese-iron silicate and chloride, from Sweden.
Goldmine. A hydrous zinc unisilicate. See p. 157.
Villarsite. Probably altered chrysolite.
Cerite, Tritomite, Erdmannite, are cerium and lanthanum silicates.
Thorite (Orangite) and JSucrasite, are thorium silicates ; the latter
hydrous.
Allophane.
In amorphous incrustations, with a smooth small-mam-
millary surface, and often hyalite-like, and sometimes pul-
verulent. Color pale bluish-white to greenish-white, and
deep green ; also brown, yellow, colorless. Translucent.
H.=3. G.= 1-85-1-89.
Composition. Mostly Al 05 Si + 6 (or 5) aq. Silica 23-75,
alumina 40*6^, water 35-63 = 100. In the closed tube yields
much water. B.B. infusible, but crumbles. A blue color
with cobalt solution, and a jelly with hydrochloric acid.
Occurs in Saxony ; at the Chessy Copper Mine near
Lyons ; at a copper mine in Bohemia ; with limonite in
Moravia ; in Old Chalk Pits near Woolwich, England ; with
gibbsite in limonite beds in Richmond, Mass. ; at the cop-
per mine of Bristol, Conn.; at Morgantown, Pa.; copper
mines of Polk County, Tenn.
Collyrite. A hydrous aluminum silicate containing only 14 to 15 per
cent, of silica, and 35 to 40 of water ; and Schrotterite is another with
11 to 12 per cent, of silica. The latter has been reported as occurring,
as a gum-like incrustation, at the falls of Little River, on Sand Moun-
tain, Cherokee Counfy, Alabama. Scarbroite is a related mineral
of doubtful nature.
HYDROUS SILICATES — ZEOLITE SECTION. 297
II. ZEOLITE SECTION.
The species of the Zeolite Section have beer/ described as
having some relation to the feldspars in constitution. In
the feldspars, as explained on page 273, the following ratios,
for the protoxides, alumina, and silica which analyses af-
ford, occur: 1:3:4,1:3:6,1:3:8,1:3:9,1:3:10, 1:3:12.
So, among the zeolites, if the water be left out of considera-
tion, these are the ratios: 1:3:4 (in Thomsonite), 1:3:6
(Natrolite, Scolecite, etc.), 1:3:8 (Analcite, Chabazite,
etc.), 1:3:10 (Harmotome), 1:3: 12 (Stilbite, Heulandite,
etc.). This fact, added to the absence or nearly total ab-
sence of magnesium and iron, and presence instead of Na2,
K2, Ca, Ba, make out a distinct relation to the feldspars,
whatever may be the part which the water sustains in the
compounds. Besides barium, strontium is sometimes pres-
ent, an element not yet known to characterize a species of
feldspar.
These minerals were called zeolites because they generally
fuse easily with intumescence before the blowpipe, the term
being derived from the Greek zeo, to boil. Among those
described beyond, Heulandite and Stilbite, have a strong
pearly cleavage, and the latter is often in pearly radiations ;
Natrolite, Scolecite, are fibrous and radiated, or in very
slender prisms ; Thomsonite occurs either radiated, or com-
pact, or in short crystals ; while Harmotome, Analcite, and
Chabazite, and the related Gmelinite, occur only in short
or stout glassy crystals, those of chabazite looking some-
times like cubes.
The zeolites are sometimes called trap minerals, because
they are often found in the cavities or fissures of amygda-
loidal trap as well as related basic eruptive rocks. Yet
they occur also occasionally in fissures or cavities in gneiss,
granite, and other metamorphic rocks. They are not the
original minerals of any of these rocks ; but the results of
alteration of portions of them near the little cavities or fis-
298 DESCRIPTIONS OP MINERALS.
sures in which the minerals occur ; and part were made
while the rock was still hot, and as cooling went forward.
Besides true zeolites, such cavities often contain also
Laumontite (p. 293), noted for its tendency to crumble
on exposure ; Pectolite and Okenite (p. 293), which are
fibrous like Natrolite and Scolecite ; Apophyllite (p. 294),
having one pearly cleavage like heulandite and stilbite ;
Prehnite (p. 295), usually apple-green ; Datolite (p. 289),
in stoutish glassy complex crystals, or in smooth botryoidal
forms ; Aragonite (p. 218), sometimes radiated fibrous, and
Calcite (p. 215) with its three directions of like easy cleav-
age, both effervescing with hydrochloric acid ; Siderite
(p. 185), in spheroidal or other forms ; Chlorite (p. 316),
of dark olive-green color ; and Quartz, either in crystals,
or as chalcedony, agate, or carnelian, and in either case
easily distinguished by the hardness, absence of cleavage,
and infusibility. Of all these species Calcite and Quartz
are the most common. Of rarer occurrence than the above,
there are Orthoclase, Asphaltic coal, Copper, etc.
All the zeolites yield water in the closed tube, and many
of them gelatinize with hydrochloric acid.
Thomsonite.
Trimetric. In right rectangular prisms. Usually in
masses having a radiated structure within, and consisting
of long fibres, or acicular crystals ; also amorphous.
Color snow-white ; impure varieties brown. Lustre vi-
treous, inclining to pearly. Transparent to translucent.
H.=5-5. Brittle. G. =2-3-2-4.
Composition. (Ca,Na2)Al 08 Si, +.2 Jaq= Silica 38-09, al-
umina 31-62, lime 12-60, soda 4-62, water 13 "40 =100 '20.
B. B. fuses very easily to a white enamel. Decomposed by
hydrochloric acid: the solution gelatinizes when evaporated.
' Diff. Distinguished from natrolite by its fusion to an
opaque and not to a glassy globule.
Obs. Occurs in amygdaloid, near Kilpatrick, Scotland ;
in lavas at Vesuvius, Comptonite; in clinkstone in Bohemia;
the Tyrol, etc. ; at Peter's Point, Nova Scotia, in trap ; a
massive variety, called Ozarkite, at Magnet Cove, Ark.
HYDROUS SILICATES — ZEOLITE SECTION.
The species was named after Dr. Thomas Thomson, of
Glasgow.
Natrolite.
Trimetric. In slender prisms, terminated by a short pyra
mid; /A/=91°; 1 Ai over a?=U3° 20'. Also
in globular, stellated, and divergent groups,
consisting of delicate acicular fibres, the
fibres often terminating in acicular prismatic
crystals.
Color white, or inclining to yellow, gray,
or red. Lustre vitreous. Transparent to
translucent. H. = 5-5'5. G. = 2 -1 7-2 -25.
Brittle.
Composition. NagAl 0,0 Si3 + 2 aq = Silica
47'29, alumina 26*06, soda 16*30, water
9 '45 = 100. B.B. fuses easily and quietly to a clear glass ;
a fine splinter melts in a candle flame. Decomposed by hy-
drochloric acid, and the solution gelatinizes on evaporation.
Diff. Distinguished from scolecite by its quiet fusion.
Obs. Found in amygdaloidal trap, basalt and volcanic
rocks; sometimes in seams in granitic rocks. The name
natrolite is from natron, soda.
Occurs in Bohemia; Auvergne; Fassathal, Tyrol; at Glen
Farg in Fifeshire ; in Dumbartonshire ; Nova Scotia ; Ber-
gen Hill, N. J.
Scolecite. Resembles natrolite, and differs in containing lime in place
of soda ; also in having its slender rhombic glassy prisms longitudi-
nally twinned, as is shown by the meeting of two ranges of striae at an
angle along or near the central line of opposite prismatic planes. The
lustre is vitreous or a little pearly. B.B. it curls up like a worm
(whence the name from the Greek skolex, a worm) and then melts.
From Staffa, Iceland, Finland, Hindostan.
Mesolite. Another related species.
Analcite.
Dimetric or Trimetric. Occurs usually in trapezohedron
(fig. 1, also fig. 2).
The appearance sometimes
seen in polarized light is
shown in figure 7, page 69
On account of this peculiar
behavior and indications of
a compound structure ob-
tained in a microscopic study
1.
300 DESCRIPTIONS OF MINERALS.
of thin slices, it has been suspected to be dimetric like
leucite, or else t rime trie like phillipsite, although the forms
of the crystals are apparently isometric. Often colorless
and transparent, also milk-white, grayish and reddish-
white, and sometimes opaque. Lustre vitreous. H. =5-5 '5.
G.=2 25.
Composition. Na2Al Oi2Si4 4- 2aq = Silica 54*47, alumina
23-29, soda 14-07, water 8-17 = 100. B.B. fuses easily to a
colorless glass. Decomposed by hydrochloric acid ; and the
silica separates in gelatinous lumps.
Diff. Characterized by its crystallization, without cleav-
age. Distinguished from quartz and leucite by giving water
in a closed glass tube ; from calcite by its fusibility, and by
not effervescing with acids ; from chabazite and its varieties
by fusing without intumescence to a glassy globule, and by
the crystalline form.
Obs. Found in cavities and seams in amygdaloid'al trap,
basalt and other eruptive rocks, and sometimes in granite,
syenyte and gneiss.
Occurs in fine crystallizations in Nova Scotia ; also at
Bergen Hill, N. J. ; Ferry, Me. ; and in the trap of the Cop-
per region, Lake Superior. The Faroe Islands, Iceland ;
Glen Farg, near Edinburgh ; Kilmalcolm, the Campsie
Hills, and Antrim ; the Vicentine ; the Hartz at Andreas-
berg ; Sicily, and Vesuvius, are some of the foreign localities.
The name analcite is from the Greek, analkis, weak, al-
luding to its weak electric power when heated or rubbed.
EudnopMte. Near analcite. From Norway.
Faujasite. In isometric octahedrons. From the Kaiserstuhl, Baden.
Chabazite.
Rhombohedral. Often in rhombohedrons, much resem-
bling cubes. R : 72=94° 46'. Cleavage parallel to
R. Also in complex modifications of this form.
Never massive or fibrous.
Color white, also yellowish, and flesh-red or red.
Lustre vitreous. Transparent to translucent. H. —
4-5. G. =2-08-3-19.
The red chabazite of Nova Scotia has been called Acadi-
alite.
Composition. CuAl 0,2 Si4-f 6aq, with a little Na2 or K2 in
place of part of the Ca. The Nova Scotia acadialite afforded
HYDROUS SILICATES — ZEOLITE SECTION. 301
Silica 52*20, alumina 18*27, lime 6 '58, soda and potash 2*12,
water 20-52. B. B. intumesces and fuses to a nearly opaque
bead. Decomposed by hydrochloric acid, with the separa-
tion of slimy silica. In the closed tube gives water. Phac-
olite is a variety in complex glassy crystals.
Diff. The nearly cubical form often presented by the
crystals of chabazite is a striking character. It is distin-
guished from analcite as stated under that species ; from
calcite by its hardness and action with acids ; from fluorite
by its form and cleavage, and its showing no phosphores-
cence.
Obs. Found in trap and occasionally in gneiss, syenyte,
and other rocks. Chabazite is met with in the trap of Con-
necticut Valley, but in poor specimens ; also at Hadlyme
and Stonington, Conn.; Charlestown, Mass.; Bergen Hill,
N. J. ; Piermont, N. Y.; Jones's Falls, near Baltimore
(Haydenite). Nova Scotia affords common chabazite, and
also the acadialite in abundance. The Faroe Islands, Ice-
land, and Giant's Causeway, are some of the foreign locali-
ties ; also the County of Antrim, Ireland.
Herschdite. Near chabazite, if not identical with it. From Sicily.
Omelinite. Closely resembles some chabazite, but its crystals are
usually hexagonal rather than rhombohedral in appearance. Formula
(Na2,Ca)Al2 O,2 Si4. A Bergen Hill specimen afforded Silica 48 67, alu-
mina 18'72, lime 2 -60, soda 9 '14, water 21 -35 =100 '48. Gelatinizes with
hydrochloric acid, but in other respects resembles chabazite. Occurs
at Andreasberg ; in Antrim, Ireland ; in Skye ; at Bergen Hill, N. J. ;
in Nova Scotia at Cape Blomidon. Named after the chemist, Gmelin.
Levynite (Let>yne\ Rhombohedral, and somewhat resembling gme-
nite in its crystals ; excluding the water, having the quantivalent
itio of labradorite, 1:3:6. Colorless, white, grayish, reddish. From
eland, Greenland, Antrim, Londonderry, Hartfield Moss near Glas-
>w. Named after the crystallographer, Levy.
Harmotome.
Monoclinic. Unknown except in compound crystals; and
commonly in forms similar to the annexed figure ; also in
compound rhombic prisms.
Color white ; sometimes gray, yellow, red, or brownish.
Subtransparent to translucent. Lustre vitreous. H. = 4'5.
Cr. = 2-45.
Composition. BaAl 014Si5 + 5 aq = Silica 46 *5, alumina 1 5 '9,
baryta 23 '7, water 13 -9 = 100 ; but a little of the baryta re-
placed by potash. B.B. whitens, crumbles, and fuses quietly
302
DESCRIPTIONS OP MINERALS.
to a white translucent glass. Gives water in a closed glass
tube. Partially decomposed by hydrochloric acid, and if
sulphuric acid be added to the solution,
a heavy white precipitate of barium sul-
phate is formed. Some varieties phos-
phoresce when heated.
Diff. Its twin crystals, when distinct,
cannot be mistaken for any other species
except phillipsite. Much more fusible
than glassy feldspar or scapolite ; does
not gelatinize in acids like thomsonite.
Ofa. Occurs in amygdaloidal trap,
and in trachyte and phonolyte, also in
gneiss, and metalliferous veins. Fine
crystallizations are found at Strontian in Scotland, and
in Dumbartonshire ; Andreasberg in the Hartz ; Kongs-
berg in Norway. Has been found in seams in the gneiss
of the upper part of New York Island.
The name harmotome is from the Greek Jiarmos, a joint,
and temno, to cleave.
Phillipsite. Near harmotome in its cruciform crystals and
other characters ; but differing in containing lime in place
of baryta. It differs also in gelatinizing with acids and in
fusing with some intumescence. It also occurs in sheaf -like
aggregations and in radiated crystallizations. From the
Giant's Causeway, Capo di Bove, Vesuvius, Sicily, Iceland.
Epistttbite. A hydrous silicate of alumina and lime. Occurs in
thin rhombic prisms, of a white color, with a perfect pearly cleavage
like stilbite.' H.=4-4'5. G.=:2'2o. Before the blowpipe froths and
forms a vesicular enamel. Does not gelatinize. From Iceland and
Hindostan, and sparingly at Bergen Hill, N. J.
Bravaisite. Supposed to be a zeolite ; it has potassium, magnesium
and iron as the protoxide bases.
Stilbite.
In pyramidally terminated rectangular prisms usually
flattened parallel to the face i~i, which is the
direction of cleavage and is very pearly in lustre.
1A1 = 119° 16', and 114°. Also in sheaf-like ag-
gregations, and thin lamellar and columnar ; also
in pearly radiated crystallizations.
Color white ; sometimes yellow, brown or red.
Subtransparent to translucent. H.= 3*5-4. G.=
2 -1-2 -15.
HYDROUS SILICATES — SEOLITE SECTION. 303
Composition. CaAl 016 Si6 + 6 aq = Silica 57*4, alumina 16*5,
lime 8-9, water 17*2=: 100; but with a little Na2or K2in
place of part of the Ca. B.B. exfoliates, swells up, and
curves into fan-like forms, and fuses to a white enamel.
Decomposed by hydrochloric acid without gelatinizing.
Diff. It cannot be scratched with the thumb-nail, like
gypsum. It is distinguished from heulandite by its crys-
tals.
Obs. Occurs mostly in trap-rocks ; also on gneiss and
granite. Found on the Faroe Ids. ; Isle of Skye ; Isle of Ar-
ran, and elsewhere, Scotland ; Andreasberg, Hartz ; the Ven-
dayah Mts., Hindostan. Found sparingly at the Chester
and Charlestown syenite quarries, Mass.; at New Haven,
Thatchersville and Hadlyme, Conn., and other points in the
Connecticut Valley trap ; at Phillipstown, N. Y.; at Bergen
Hill, N. J. ; in trap, in the copper region of Lake Superior ;
in beautiful crystallizations at various points in Nova
Scotia.
The name stilbite is derived from the Greek stilbe lustre.
It has also been called desmine, and in Germany heulandite,
where heulandite has been called stilbite.
Heulandite.
Monoclinic. In right rhomboidal prisms like the figure,
with perfect pearly cleavage parallel to P and other
planes vitreous in lustre. P on M or T=90° ; M on T
r=129° 40'. Color white ; sometimes reddish, gray,
brown. Transparent to subtr°nsl cent. Folia brit-
tle. H. =3-5-4. G. =2-17- *•&
Composition. CaA10,6Si, + 5 aq= Silica 59*1, alu-
mina 16-9, lime 9'22, water 14-8=100. Contains
1 to 2 per cent, of Naf or K2 in place of part of the
Ca. Blowpipe characters like those of stilbite. In-
tumesces and fuses, and becomes phosphorescent. Dis-
solves in acid without gelatinizing.
Diff. The very pearly lustre of the cleavage face is a
marked characteristic. 'Distinguished from gypsum by its
hardness ; from apophyllite and stilbite by its crystals ; and
from the latter species also in not occurring in radiated
crystallizations.
Obs. Found in amygdaloidal cavities and fissures in
trap ; occasionally in gneiss, and in some metalliferoug
304 DESCRIPTIONS OP MINERALS.
veins ; in large crystallizations at Berufiord, Iceland ;
and Vendayah Mts., Hindostan ; also at Isle Skye ; near
Glasgow ; Fassa Valley ; at Bergen Hill, N. J., in trap ; at
Hadlyme, Conn., and Chester, Massachusetts, on gneiss ;
near Baltimore, on a syenitic schist (Beaumontite) ; at
Peter's Point and Cape Blomidon, and other places in
Nova Scotia, in trap.
The species was named by Brooke after Mr. Heuland,
of London.
Brewstcrite. Crystals monoclinic with a perfect pearly cleavage
like heulandite ; but M : T = 93° 40'. H.=4i-5. G.=2 45. The for-
mula is analogous to that of heulandite, but baryta and strontia take
the place of the lime and soda.
Epistilbite. Composition like that of beulandite, but occurs in short
and very obtuse rhombic prisms, (/A/=135° 10'), at Skye ; the Faroe
Ids., in Iceland ; at Margaretville, in Nova Scotia.
Mordenite. Fibrous mineral from Morden, Nova Scotia.
Pilinitc. In slender needles, from Silesia.
' Foresite. Near stilbite. From Elba.
III. MARGAROPHYLLITE SECTION.
Talc.
Trimetric. In right rhombic or hexagonal prisms. I/\l
= 120°. Usually in pearly foliated masses, separating easily
into thin translucent folia. Sometimes stellate, or diver-
gent, consisting of radiating laminae. Often massive, con-
sisting of minute pearly scales ; also crystalline granular, or
of a fine impalpable texture.
Lustre eminently pearly, and feel unctuous. Color some
shade of light green or greenish white ; occasionally silvery
white; also grayish green and dark olive-green. H. =1-
1*5; easily impressed with the nail. G. =2*5-2-8. Lam-
inae flexible, but not elastic.
There are the following varieties :
Foliated Talc. The pure foliated talc, of a white or
greenish-white color.
Soapstone or Steatite. Gray or grayish green, and either
massive, crystalline granular, or impalpable ; very greasy to
the touch. French chalk is a milk-white variety, with a
pearly lustre. Potstone or Lapis Ollaris is impure soap-
stone of grayish-green and dark-green colors, and slaty
structure.
HYDROUS SILICATES — MARGAROPHYLLITE SECTION. 305
Indurated Talc, is a slaty talc, of compact texture, and
above the usual hardness, owing to impurities.
Rensselaerite. A compact crypto-crystalline rock, from
St. Lawrence and Jefferson counties, N.Y., of white, yellow,
or grayish-white colors, and even black. It has sometimes
the form and cleavage of pyroxene, and is in part at least a
product of the alteration of that mineral.
Composition. ^H2 f Mg 03 Si = Silica 62-8, magnesia 33'5,
water 3'7 = 100. It usually contains a little iron replacing
magnesium. 13. B. infusible. Moistened with cobalt nitrate
assumes a pink tint. Not acted upon by hydrochloric acid.
In closed tube gives a little water, but not till highly
heated.
Diff. The softness, unctuous feel, foliated structure, when
crystallized, and pearly lustre of talc are good characteris-
tics. It differs from mica also in being inelastic, although
flexible ; from chlorite, kaolinite, and serpentine in yielding
little water when heated in a glass tube. Only the massive
varieties resemble the last-mentioned species, and chlorite
has a dark olive-green color. Pyrophyllite, which cannot be
distinguished in some of its varieties from talc, becomes
dark blue when moistened wifch cobalt nitrate and ignited.
Obs. Occurs in Cornwall, near Lizard Point ; at rortsoy
in Scotland ; at Croky Head, Ireland ; in the Greiner
Mountain, Saltzburg. Handsome foliated talc occurs at
Bridgewater, Vt. ; Smithfi Id, R. I. ; Dexter, Me. ; Lock-
wood, Newton and Sparta, N. J., and Amity, N. Y. On
Staten Island, near the Quarantine, both the common and
indurated are obtained ; at Cooptown, Md., green, blue,
and rose-colored talc occur. Steatite or soapstone is abun-
dant, and is quarried at Grafton, Vt., and an adjacent
town ; at Francestown and Orford, N. H. It also occurs
at Keene and Richmond, N. H. ; at Marlboro' and New
Fane, Vt. ; at Middl field, Mass. ; in Loudon County, Va.,
and at many other places.
Steatite may be sawn into slabs and turned in a lathe. It
is used for firestones in furnaces and stoves, and fire-places.
It receives a polish after being heated, and has then a deep
olive-green color. The finer kinds are made into images in
China, and into inkstands and other forms in other coun-
tries. Potstone is worked into vessels for culinary pur-
poses in Lombardy. The harder kinds are cut into gas jets.
Steatite is also used in the manufacture of porcelain ; it
306 DESCRIPTIONS OP MINERALS.
makes the biscuit semi-transparent, but brittle and apt to
break with slight changes of heat. It forms a polishing
material for serpentine, alabaster and glass. " French
chalk" is used for removing grease-spots from cloth, as
well as for tracing on cloth. When ground up, soapstone
is employed for diminishing the friction of machinery.
Pyrophyllite.— Agalmatolite, in part.
Near talc in crystallization, cleavage, its occurrence in
fine-grained massive forms, its greasy feel, its white to pale-
green colors, varying to yellowish, its feeble degree of hard-
ness (1-2). The folia are sometimes radiated. G.=2'75-
2-92.
Composition. An aluminous bisilicate, instead of a mag-
nesian, for the most part of the formula, Al 09 Si3. The
Chesterfield, S. C.,; mineral afforded Genth, Silica 64-82,
alumina 24*48, iron sesquioxide 0*96, magnesia 0*33, lime
0-55, water 5-25 — 100-39. B.B. whitens and fuses with dif-
ficulty on the edges. Gives a deep blue color with cobalt
solution. Yields water in the closed tube. Kadiated varie-
ties exfoliate in fan-like forms.
Obs. Compact pyrophyllite is the chief constituent of a
kind of slate or schist, which is used for slate pencils, and
henee is called pencil-stone. Occurs in the Urals ; at \Ves-
tana in Sweden; in Elfdalen, with cyanite ; foliated, in
North Carolina, in Cottonstone Mountain ; in South Caro-
lina, in Chesterfield District, with lazulite and cyanite ;
Georgia, in Lincoln County, on Graves Mountain ; in Ar-
kansas, near Little Rock ; compact slaty in the Deep River
region, N. C., and at Carbonton, Moore County, N. C.
Sepiolite. — Meerschaum of the Germans.
Usually compact, of a fine earthy texture, with a smooth
feel, and white or whitish color ; also fibrous, white to bluish-
green in color. H.=2-2-5. The earthy variety floats on
water.
Composition. iH2 f Mg 03 Si 4- 1£ aq = Silica 60-8, magnesia
27*1, water 12-1 = 100. B.B. infusible, or fuses with great
difficulty on the thin edges. Much water in a closed tube.
A pink color with cobalt solution.
Occurs in Asia Minor in masses in stratified earthy de-
posits, and is extensively used for pipe bowls ; also found in
HYDROUS SILICATES — MARGAROPHYLLITE SECTION. 307
Greece, Moravia, Spain, etc. ; also in fibrous seams at a sil-
ver mine in Utah.
Aphrodite. Similar to the preceding. MgOsSi+fH. From Swe-
den. Cimolite, a clay from the Island of Argentiera, Kimole of the
Greeks. Smectite, a kind of "Fuller's Earth," a name given to unc-
tuous clays used in fulling cloth. MontmoriUonite, Stolpenite, and
Steargillite, are related clay-like minerals.
Glauconite. — Green Earth.
In dark olive-green to yellowish-green grains, or granular
masses, with dull lustre. H. =2. G.^2^-2-4.
Composition. Essentially a silicate of iron and potassium.
Formula RR 012 Si4, in which R is mainly Fe and K, with
sometimes Mg ; and R is Al, but sometimes largely Fe. Analy-
ses give mostly 50-58 per cent, silica, 20-24 iron protoxide,
4-12 of potash and 8-12 of water. B.B. fuses easily to a
magnetic glass. Yields water in a closed tube.
Obs. In a more or less pure state it forms thick beds in
the Cretaceous formation, and also in the Lower Tertiary
of New Jersey ; also occurs in other older rock formations
down to the Lower Silurian. Found also, first by Four-
tales, in the pores of corals and cavities of Rhizopod shells
over the existing sea-bottom, showing it to be a marine
product, and one now in progress of formation. The grains
of the Cretaceous, Tertiary, and Lower Silurian beds have
been shown by Ehrenberg to be the casts of the interior of
shells of Rhizopods. The silica has been supposed to come
from the siliceous secretions of a minute sponge growing in
the cavities that afterwards became occupied by the glau-
conite.
Celadonite. A green earth with 53 per cent, of silica, from amygda-
loid, near Verona. Probably an impure chlorite.
Chloropal. A massive greenish-yellow to pistachio-green compact
mineral, somewhat opal-like in appearance, consisting chiefly of silica,
iron sesquioxide, and water. Montronite, Pinguite, Unghwarite and
Gramenite are varieties of it.
Stilpnomelane. Foliated and also fibrous, or as a velvety coating.
Black to brownish and yellowish bronze in color and lustre. G.=
3-8-4. Chiefly silica and iron oxides, with 8 to 9 per cent, of water.
Chalcodite of the Sterling Iron Mine, Antwerp, Jefferson County,
N. Y., is here included.
Serpentine.
Usually massive and compact in texture, of a dark oil-
green, olive-green, or blackish-green color ; also pale yel-
308 DESCRIPTIONS OP MINERALS.
lo wish-green, brownish-yellow and brownish-red. Occurs
also fibrous and lamellar. The lamellar varieties consist of
thin folia, sometimes separable, but brittle ; colors green-
ish-white, and light to dark green. Often in crystals pseu-
domorphous after chrysolite, chondrodite, and some other
minerals.
Lustre weak ; resinous, inclining to greasy. Finer varie-
ties translucent; also opaque. H. =2'5-4. G. = 2'5-2*6.
Feel sometimes a little unctuous. Tough. Fracture con-
choidal.
Composition. A hydrous silicate of magnesium, like talc,
but containing much more water and much less silica.
HjMg308Si2 + l aq = Silica 43 '48, magnesia 43*48, water
13'04 = 100. B.B. fuses with much difficulty on thin edges.
Yields water in the closed tube. Decomposed by hydro-
chloric acid, leaving a residue of silica. In some kinds the
Mg is replaced partly by Fe.
Specimens of a rich oil-green color, and translucent,
bi caking with a splintery fracture, are sometimes called
precious serpentine, and the opaque kind, common serpen-
tine.
Fibrous serpentine with a silky lustre is called Chrysotile,
and also Amianthus. Unlike asbestus, which it resembles,
it affords much water in a closed tube. Metaxite, Picro-
lite, and Baltimorite are coarse fibrous kinds. A foliated
variety, from Hoboken, N. J., was named Marmolite, be-
fore it was known to be serpentine. Antiyorite is a foli-
ated variety. Williamsite is similar. Refdanskite contains
nickel.
A porcelain-like serpentine — the Meerschaum of Taberg
and Sala — has been called Porcello$)hite ; and a resin-like
variety, Retinalite and Vorhauserite.
Diff. The distinguishing characters are feeble lustre,
somewhat resinous, compact structure, little hardness, being
so soft as to be easily cut with a knife, and specific gravity
not over 2*6.
Obs. Serpentine occurs as a rock, and the several varie-
ties mentioned either constitute the rock or occur in it.
Occasionally it is disseminated through granular limestone,
giving the latter a clouded green color : this is the verd an-
tique marble, called also Opliiolyte.
Serpentine occurs in Cornwall ; near Portsoy in Aber-
deenshire, in Corsica, Siberia, Saxony, Norway at Snarum.
HYDROUS SILICATES — MARGAROPHTLLITE SECTION. 309
In the United States it occurs at Phillipstown, Port Henry,
Gouverneur, Warwick, N. Y. ; Newburyport, Westfield,
and Bltindford, Mass.; at Kellyvale and New Fane, Vt. ;
Deer Isle, Maine ; New Haven, Conn. ; Bare Hills, Md. ;
Hoboken, N. J. ; at Brewster's, Putnam County, N. Y.,
where it occurs pseudomorphous after chondrodite, chlo-
rite, enstatite, biotite, etc. ; in Canada at Orford, Ham, Bol-
ton, etc.
Serpentine forms a handsome marble when polished, es-
pecially when mixed with limestone, constituting verd-
antique marble. Its colors are often beautifully clouded,
and it is much sought for as a material for tables, jambs
for fire-places, and ornamental in-door work. Exposed to
the weather, it wears uneven, and soon loses its polish.
Chromic iron is usually disseminated through it, and in
creases the variety of its colors. Near Milford and New
Haven, Conn., a handsome verd-antique marble occurs
which was formerly worked. A white limestone, dotted
and spotted with green serpentine at Port Henry, Essex
County, N. Y., is much esteemed for its beauty, and is now
extensively worked. The name serpentine alludes to the
varied green colors of such rocks.
Bowenite from Smithfield, R. I., has the composition of serpentine,
but the hardness 5 '5-6, and the aspect of nephrite, with G. —2 '59-2' 8.
Bastlte or Schiller Spar, is a foliated pyroxene or bronzite altered
nearly to serpentine. AntUlite is similar.
Deweylite.
Massive. Whitish, yellowish, brownish-yellow, greenish,
reddish, in color, with the aspect of gum arabic or a resin.
Very brittle. H. =2-3 5. G. = l'9-2-25.
In composition near serpentine but containing 20 per
cent, of water. From Middlefield, Mass. ; Bare Hills,
Maryland (Qymnito); T^xas, Pa., and from the Fleims Val-
ley, Tyrol.
Cerolite. Related to deweylite ; from Silesia. Limbachito from Lim*
bach, and Zoblitzite from Zoblitz, are similar.
Hydrophite. Like deweylite, but containing iron in place of part
of the magnesium. From Taberg in Smaoland. Jenkinsite is a
fibrous variety, occurring on magnetite, at O'Neil's mine in Orange
County, N. Y.
Genthite or Nickel-gymnite. Similar to deweylite, but containing
much nickel and G.= 2 '4, analysis affording Silica 35 '36, nickel pro-
toxide 30-64, iron protoxide 0'24, magnesia 14*60, lime 0'26, water
310 DESCRIPTIONS OP MINERALS.
19- 09 =100 -19. From Texas, Pa. ; Webster, N. C. ; Michipicoton
Island, Lake Superior ; Malaga, Spain ; Saasthal, Upper valois.
Eottisite is similar.
Saponite.
Soft, clay-like, of the consistence before drying of cheese
or butter, but brittle when dry. Color white, yellowish,
grayish-green, bluish, reddish. Does not adhere to the
tongue.
Composition. A hydrous silicate of magnesia containing
some alumina.
From Lizard's Point, Cornwall, in serpentine. Also from
geodes of datolite, Roaring Brook, Conn. ; in trap, north
shore of Lake Superior.
Eaolinite.
Trimetric. /A 7= 120°. Occurs massive, clay-like, but
consisting usually of thin, microscopic, rhombic or hex-
agonal, crystals ; either compact, friable, or mealy.
Color wliite, grayish-white, yellowish, sometimes brown-
ish, bluish, or reddish. Scales transparent or translucent ;
flexible, inelastic, greasy to the touch. H. = 1-2 '5. G.=
2-4-2-6.
Composition. H2A1 08 Si2 + l aq= Silica 46 '4, alumina 39*7,
water 13'9 = 100. The similarity of the composition to that
of serpentine will be seen on comparing the two formulas.
B. B. infusible. A blue color with cobalt solution. Yields
water in the closed tube. Insoluble in acids.
Obs. The soapy feel of kaolinite distinguishes a clay con-
sisting of it from other kinds of clay ; and when common
clays are " unctuous " it is usually owing to the presence of
kaolinite. Kaolinite has been made through the decompo-
sition of aluminous minerals, and especially the potash and
soda feldspars, orthoclase, albite, and oligoclase. In the
case of these feldspars the process (1) removes the alkalies ;
(2) leaves the alumina, or a large part of it, and part of the
silica ; and (3) adds water. So that, with orthoclase, K2Al
O16 Si6 becomes changed to H2A1 08Si2 + l aq ; half the water
which is added replaces K2 which is removed. Many gran-
ites, gneisses, and other feldspar-bearing rocks undergo
rapidly this change, so that extensive beds of kaolinite have
been formed and are now making in many regions. The
kaolinite is usually washed out by streams or the waves from
the decomposed material to make the large pure deposits.
HYDROUS SILICATES — MARGAROPHYLLITE SECTION. 311
The New Jersey clay-beds of the Cretaceous formation are
mainly kaolinite, and have been thus formed. In other
cases permeating waters have washed out the oxides of iron
present, and have left the white clay in place. A pure
kaolinite bed occurs at Brandon, Vermont, along with a
limonite bed, where the rock decomposed was probably a
feldspathic hydromica slate. Most of the limonite beds of
Western New England afford kaolinite ; yet it is generally
more or less colored by iron oxide.
Common clays consist of finely-powdered feldspar, quartz,
and other mineral material, with often more or less kaoli-
nite. They burn red in case they contain iron in the state
ordinarily present in them of iron carbonate, or hydrous
iron oxide (limonite), or in combination with an organic
acid, or in some other alterable state of composition, heat
driving off the carbonic acid or water, or destroying the or-
ganic acid, and so leaving the red oxide of iron (or sesqui-
oxide), or favoring its production. But the iron may be so
combined as not to give the red color; and this has been
found to be true with the clays from which the cream-col-
ored Milwaukee (Wisconsin) brick are made, and that of
other clay beds in that vicinity. The iron may be there in
the state of the silicate, zoisite, or epidote.
Pure kaolinite (or kaolin as it is ordinarily called) is
used in making the finest porcelain. For this purpose it is
mixed with pulverized feldspar and quartz, in the proportion
needed to give, on baking, that slight incipient degree of
fusion which renders porcelain translucent. The name
kaolin is a corruption of the Chinese word Kauling, mean-
ing high ridge, the name of a hill near Jauehau-Fu, where
the mineral is obtained; and i\\Qpetuntze (peh-tun-tsz) of the
Chinese, with which the kaolin is mixed in China for the
manufacture of porcelain, is, according to S. W. Williams,
a quartzose feldspathic rock* consisting largely of quartz.
The word porcelain was first given to China-ware by the
Portuguese, from its resemblance to certain sea-shells called
Porcellana; they supposed it to be made from shells, fish-
glue, and fish-scales (8. W. Williams).
The impure kaolin is used for stoneware and fire-bricks.
The presence of iron, in any state, makes a clay more or
less fusible, and therefore an unfit material for fire-bricks.
But a little of it exists in all clays employed for making or-
dinary bricks, and hence their red color.
312 DESCRIPTIONS OF MINERALS.
Pholerite, Hattoysite, Smectite, Severite, Glagerite, Lenzinite, Bole, Li
thomarge, are names of clay-like minerals.
Finite.
Amorphous, and usually cryptocrystalline ; but often
having the form of the crystals of other minerals from the
alteration of which it has been made. Colors grayish, green-
ish, brownish, and sometimes reddish. Lustre feeble; waxy.
Translucent to opaque. Acts like a gum on polarized light,
and thus indicates the absence of true crystallization, even
when under the forms of crystals. H.=2'5-3. G.— 2-6-2'85.
Composition. Mostly (H3K)2A12 Qm Sis. The pinite of Saxony
afforded Silica 46-83, alumina 27*65, iron sesquioxide 8 -71,
magnesia 1-02, lime 0*49, soda 0'40, potash 6 '52, water 3 '83
= 99-42 ; and, in another analysis, potash 10*74. The phy-
sical characters ally it to serpentine, and also nearly the
atomic ratio, and it may be viewed as a potash-alumina ser-
pentine. But at the same time it has very nearly the com-
position of a hydrous potash mica, or damourite (see next
page).
Obs. The varieties are pseudomorphs after different min-
erals, and hence comes a part of their variations in compo-
sition. They include Pinite, from the Pini Mine, near
Schneeberg and elsewhere ; Gieseckite, pseudomorph after
nephelite from Greenland, and from Diana, N. Y. ; Dysyn-
tribite, from Diana, identical with gieseckite ; Pinitoid,
from Saxony ; Wilsonite, from Bathurst, Canada, having
the cleavage of scapolite ; Terenite, from Antwerp, N. Y.,
like Wilsonite ; Agalmatolite, or Pagodite, from China, be-
ing one of the materials for carving into images, ornaments,
models of pagodas, etc. ; gigantolite and iberite, which have
the form of iolite.
Polyargite, Eosite, Cataspilite, Biharite are related materials.
Palagonite. Yellow to brownish yellow, garnet-red to black in
color, and resinous to vitreous in lustre. The material of some tufas,
and the result of change through the agency of steam or hot water at
the time, probably, of the deposition of the material. From tufas of
Iceland, Germany, Italy, Sicily, and named from Palagonia, in Sicily.
HYDROMIOA GROUP.
The following species are mica-like in cleavage and aspect,
but talc-like in wanting elasticity, greasy feel, ajid pearly
lustre. They arc sometimes brittle. Common mica, mus-
HYDROMICA GROUP. 313
covite, readily becomes hydrated on exposure ; but hydrous
micas are not all a result of alteration. The Hydromica
slates form extensive rock-formations, equal to those of the
ordinary mica schists. They were for the most part called
Talcose slates (or Talk-scUiefer in German) from their greasy
feel, until the fact was ascertained that they contained no
magnesia : a point demonstrated for the Taconic slates of
the western border of Massachusetts, by C. Dewey, in 1819,
and later, by G. F. Barker, for those of Vermont. Finite
is related in composition, but is not micaceous.
Margarodite.
Like muscovite (page 267), but inelastic.
Composition. Specimens from the topaz vein, Trunftmll,
Conn., afforded Silica 46'50, alumina 33 '91, iron sesquiox-
ide 2-69, magnesia 0-90, soda JJ '70, potash 7'32, water 4-63,
fluorine 0-82, chlorine 0-31 = 99-78. Another from Litch-
field, Conn., accompanying cyanite, afforded water 5*26 per
cent., soda 4-10, potash 6-20, showing a large percentage of
soda. It is probable that both of these micas were originally
hydrous.
Damourite.
Mica-like, consisting of an aggregation of fine pearly scales,
yellow to white in color.
Composition. Near margarodite, being a hydrous potash
mica. A specimen from Brittany afforded Silica 45-22,
alumina 37 '85, potash 11 '20, water 5-25 = 99-52. The quan-
tivalent ratio for the protoxide, sesquioxide, silica, and
water is 1: 9: 12:2, instead of that of margarodite, which is
1:6:9:2. A schistose hydromica slate from Lehigh County,
Pennsylvania, afforded Dr. Genth, Silica 49 '92, alumina
34-06, iron sesquioxide 0*91, magnesia 1/77, lime 0-11, soda
0-74, potash 6 -94, water 6 -52 = 100-97.
Obs. From a locality of cyanite in Brittany, and another
in Warmland ; also the constituents of a garnetiferous schist
at Salm-Chateau, in Belgium; and in part of extensive
schistose formations in Vermont, Western Massachusetts,
"Western Connecticut, and also just west of New Haven,
Connecticut ; Eastern Pennsylvania, etc.
314 DESCRIPTIONS OF MINERALS.
For other analyses of hydromica slates, see Dr. Genth's report on
the Mineralogy of Pennsylvania ; also Geological Report of F. Prime,
Jr., for 1874, p. 12.
Parophitc. The material of a schist or slate — Parophite Schist —
which cuts like massive talc, is of greenish, yellowish, reddish, and
grayish colors, and is probably a damourite or hydromica slate, with
some free silica (quartz). An analysis afforded Silica 48 '46, alumina
27*55, iron protoxide 5 '08, magnesia 2 '02, lime 2 '05, ^oua 2 '35, potash
516, water 7 14=99 '81. It is from Pownal, Vt., and St. Nicholas,
Stanstead, and other neighboring parts of Canada.
Sericite. A damourite-like mineral, with the pearly lustre of talc,
and the composition of a hydrous mica ; it is the basis of a glossy
schist ; near Wiesbaden. The scales are described by Rosenbusch as
appearing fibrous when highly magnified. Analysis afforded Silica
49-00, alumina 23'65, iron protoxide 8*07, magnesia 0 94, lime 0*63,
soda 1*75, potash 9 '11, water 3 '47, titanic dioxide 1/39, silicon fluoride
1-60=100-14.
Paragonite. A hydrous mica containing soda in place of potash.
From Mount Campione, in the region of St. Gothard. Color whitish,
grayish, yellowish, greenish. Analysis afforded Silica 46 '81, alu-
mina 40 06, magnesia 0'65, lime 1*26, soda 6 '40, potash trace, water
4-82=100. Pregrattite. from the Tyrol, afforded soda 7'06, potash
1-71, water 5 '04 ; it exfoliates like the Vermiculites. Cossaite is here
included.
Groppite. A rose-red to brownish-red foliated mineral from Gropp-
torp, Sweden.
EuphyUite. Mica -like, with folia rather brittle, pearly lustre,
white or colorless. Contains much sodium. An analysis afforded
Silica 41-6, alumina 42*3, lime 1 -5, potash 3 '2, soda 5 '9, water 5 '5 =100.
Occurs with corundum at Unionville, Delaware County, Pa.
(EUacherite. Mica-like ; strong pearly in lustre, grayish white to
white ; elastic. Analysis obtained 7 '61 potash, 1'42 soda, 4*65 baryta,
and 4'43 water, besides silica, alumina, etc.
Cookeite. In minute mica-like scales, and in slender six-sided
prisms. Affords only 2 '57 of potash, with 2 '82 of lithia ; the water
13*41 per cent. Occurs on crystals of red tourmaline at Hebron and
Paris, Me., and has proceeded from its alteration. Named after Prof.
J. P. Cooke, of Cambridge, Mass.
Voigtite is the mica of a granite at Ehrenberg, near Ilmenau, which
has the composition of biotite, plus 9 to 10 per cent, of water.
Roscoelite. A vanadium-mica, of dark brownish-green color, occur-
ring in micaceous scales, and affording over 20 per cent, of vanadium
oxides, along with 47*69 of silica, 14'10 of alumina, 7 '59 of potash,
4*96 of water, and a little magnesia and soda. From Granite Creek
Gold Mine, El Dorado County, California.
Fahlunite0
In six and twelve-sided prisms, usually foliated, parallel
to the base, but owing its prismatic forms to the mineral
from which it was derived. Folia soft and brittle, of a
HYDROUS SILICATES. 315
grayish-green to dark olive-green color, and pearly lustre.
G. =2-7.
Composition. A hydrous silicate of aluminum and iron
with little or no alkali, and in this last point differing from
pinite. An average specimen afforded Silica 44-60, alumina
30-10, iron protoxide 3-86, manganese protoxide 2-24, mag-
nesia 6*75, lime T35, potash 1-98, water 9'35 = 100-2-3.
B.B. fuses to a white glass. In a closed tube gives water.
Insoluble in acids.
Diff. It is distinguished from talc by affording much
water before the blowpipe, and readily by its association
with iolite, and its large hexagonal forms, with brittle folia.
Obs. Fahlunite has been derived from the alteration of
iolite. The quantivalent ratio of iolite for the protoxides,
sesquioxides, and silicon is 1:3:5; and for fahlunite, the
same, with 1 for the water, making the whole 1:3:5:1. The
hydration appears to go on at the ordinary temperature,
and in some localities all the iolite to a considerable depth
in the rock is changed to fahlunite. There are different
varieties, depending on the amount of water, and the con-
ditions under which the change has taken place. The
names they have received are Hijdrous Iolite, Chlorophyllite,
Esrnarkite, Aspasiolite, Pyrargillite, Triclasite. Fahlunite
was so named from its locality, Fahlun, Sweden ; and Chlo-
Tophyllite from its greenish color and foliated structure ; the
specimens to which it was given occurring at Unity, N. H.
Haddam, Ct., is another locality. Gigantolite, Iberite, are
also altered iolite, but they contain potash, and belong
hence to the Pinite Group.
Hisingerite.
Massive ; reniform ; of a black to brownish-black color,
yellowish-brown streak, greasy lustre inclining to vitreous.
H.=3. G.=3'045.
Composition. A hydrous iron silicate. Silica 35'9, iron
sesquioxide 42'6, water 21-5 = 100. But in some analyses
part of the iron is in the protoxide state. B.B. fuses with
difficulty to a magnetic slag.
Obs. From Sweden, Norway, Finland. Scotiolite and
Deyeroite are referred to it. Melanolite, from Milk-Row
quarry, near Charlestown, Mass., is related in composition,
if the material analyzed was a pure species.
316 DESCRIPTIONS OF MINERALS.
Approaches in composition the chlorites, and may belong
to that group.
Gillingite from Sweden, including Thraulitc from Bavaria, EpicMo-
rite, and Lillite, are other hydrous silicates containing iron .
Ekmannite, foliated, chlorite-like, occurs in the rifts of magnetite,
in Sweden ; it is a hydrous iron silicate, but the iron is mostly in the
protoxide state.
Neotocite (Stratopeite) and Wittingite are results of the alteration of
rhodonite, and contain manganese. Stubelite also contains manganese
oxide.
Slrigomte from Striegau, Siberia, and Jollyte from Bodenmais in
Bavaria, are hydrous silicates of aluminum and iron, with little mag-
nesium.
CHLORITE GROUP.
The chlorite group includes the hydrous Subsilicates of
the Margarophyllite Section and also some related species
that are Unisilicates. The proportion of silica is small, the
percentage afforded by analyses being under 38, and mostly
under 30. The minerals when well crystallized are foliated
like the micas, and have the plane angle of the base of the
crystals 120°, but the folia are inelastic and in some species
brittle. They also occur in fibrous and in fine granular and
compact forms, and the latter are usually most common.
Green, varying from light to blackish green, is the prevail-
ing color, yet gray, yellowish, reddish, and even white and
black also occur ; and the colored transparent or translu-
cent are dichroic. The green color is owing to the presence
of iron, and fails only in species containing little or none
of it. All of the species yield water in a closed tube.
The quantivalent (or combining-power) ratio for R + & and
Si is, in the
Pyrosclerite subdivision 1:1.
Chlorite subdivision 1 : i, 1 : f, 1 : £.
Chloritoid subdivision 1 : £ to 1 : £.
The chlorite subdivision includes Penninite, Ripidolite
and Prochlorite, together with some related dark -green to
blackish-green species. Some species of this subdivision
characterize extensive rock formations, making chlorite
CHLORITE GROUP. 317
schist or slate ; and they give rise also to chloritic varieties
of other rocks. Moreover, chlorite is a result of the altera-
tion of pyroxene, hornblende, and some other iron-bearing
minerals ; and pyroxcnic igneous rocks, like doleryte, are
often strongly chloritic (as revealed by the microscopic
examination of thin transparent slices), in consequence of
this alteration — but alteration that took place before the
rock had cooled. Such green chloritic material, where the
species is not determinable, has been called Viridite. The
cavities in amygdaloid are often lined, and sometimes filled,
by a species of chlorite, which was made from certain con-
stituents of the amygdaloid in the manner just stated ; and
the rocks adjoining trap dikes are at times penetrated by
chlorite made in them by means of the heat, and the mois-
ture contained in them or ascending with the erupted rock.
Pyrosclerite.
Trimetric or monoclinic. Mica-like in cleavage ; folia
flexible, not elastic, and pearly in lustre. Color apple-green
to emerald-green. H.=3. G. =2'74.
Composition, (f Mgs JA1), 018 Si3 + 3 aq = Silica 38 '9, alu-
mina 14-8, magnesia 34-6, water 11'7=100. B.B. fuses to a
grayish glass ; gelatinizes with hydrochloric acid.
Obs. Occurs in serpentine, on Elba.
Chonicrite (Metaxoite) is related to the above in composition, but
affords 13 to 18 per cent, of linie.
Vermiculite.
Mica-like in cleavage. Grayish, brownish, and yellowish-
brown in color. In aggregated scales. Also in large mi-
caceous crystals or plates. Laminae flexible, not elastic.
Lustre pearly.
Composition. Mg3 (Fe,Al) 012Si3. When heated it exfo-
liates, and when scaly-granular the scales open out into
worm-like forms ; and thence the name, from the Latin
vermicular, I breed worms ; B.B. fuses finally to a gray
mass. From Milbury, Mass.
Jefferisite is a similar mineral in composition and exfoliation, occur-
ring in broad folia. Composition £Mg3£(Fe2,Al2)O12 Si3. From veins
in serpentine in Westchester, Pa. Culsageeite from Culsagee, North
318 DESCRIPTIONS OP MINERALS.
Carolina ; Hallite from Lerni, Delaware Co., Pa. ; Protovermiculite
from Magnet Cove, Ark., are other micaceous hydrous unisilicates
similar to vermiculite and jefferisite in exfoliation. Kerrite and
Maconite are related to the above. They are from Franklin, Macon
Co., North Carolina. Pdhamite is from Pelham, Mass.
Penninite. — Chlorite in part. Pennine.
Khombohedral. Cleavage basal and highly perfect, mica-
like. Also massive, consisting of an aggregation of scales,
and cryptocrystalline.
Color green of various shades ; also yellowish to silver-
white, and rose-red to violet. Lustre pearly on cleavage
surface. Transparent to translucent. Laminae flexible,
not elastic. H. = 2-2-5, 3 on edges. G.= 2 -6-2-85.
Composition. A specimen from Zermatt, in the Pennine
Alps, aiforded Silica 33-64, alumina 10'64, iron sesquioxide
8-83, magnesia 34-95, water 12-40=100-46. The rose-red,
from Texas, Pa., gave Silica 33*20, alumina 11-11, chro-
mium oxide 6-85, iron sesquioxide 1*43, magnesia 35 '54,
water 12-95, lithia and soda 0-28, potash 0-10 = 101-46.
Other Texas specimens afforded 0-90 to 4'78 per cent, of
chromium oxide. B.B. exfoliates somewhat and fuses with
difficulty. Partially decomposed by hydrochloric acid, and
wholly so by sulphuric acid.
From Zermatt, Ala in Piedmont, the Tyrol, etc. Kdm-
mererite, Rhodochrome, and Rhodophyllite include the red-
dish variety from near Miask, Russia ; Texas, Pennsylva-
nia ; etc. Pseudomorphs after hornblende, named Loganitt
have the composition of this species ; and so has the mas-
sive mineral called P seudopliite and Allophite.
Ddessite. A fibrous mineral near the above in composition, from
amygdaloid at Oberstein.
Euralite is an amorphous chlorite near Penninite, from Eura, Fin-
land ; from amygdaloid.
Diabaniite (Diahantoclironyri] is a chlorite from amygdaloid. A
Farmington (Conn.) specimen afforded Hawes, Silica 33 "68, alumina
10'84, iron sesquioxide 2'86, iron protoxide 24'33, MnO and CaO I'll,
magnesia 16'52, soda 0'33, water 10'02=99-69.
Chlorophwite is a doubtful species of chlorite, from amygdaloid.
Ripidolite.— Chlorite, in part.
Monoclinic. Similar in cleavage and mica-like character
to penninite, and also in its colors, lustre, hardness and
specific gravity.
CHLORITE GROUP. 319
Composition. A specimen from Chester Co. , Pennsylvania,
afforded Silica 31*34, alumina 17-47, chromium sesquioxide
1 -69, iron sesquioxide 3*85, magnesia 33-44, water 12-60=
100 "39. B.B. and with acids nearly like penninite. A va-
riety from Willimantic, Ct., exfoliates like vermiculite and
jefferisite.
Kotscliubeite is a red variety from the Urals.
Clinochlore and Grastite are here included. Occurs at
Achmatovsk and elsewhere in the Urals ; at Ala, Piedmont ;
at Zermatt ; at Westchester, Union ville and Texas, Pa. ; at
Brewster's, N. Y.
Prochlorite. — Chlorite in part.
Hexagonal. Similar in cleavage and mica-like characters
the preceding. Color green to blackish-green ; some-
imes red across the axis by transmitted light. Laminae
>t elastic.
Composition. A specimen from St. Gothard afforded Sili-
25*36, alumina 18*56, iron protoxide 28 '79, magnesia
17*09, water 8-96 = 98-70 ; and a North Carolina specimen,
Silica 24-90, alumina 21*77, iron sesquioxide 4*60, iron
protoxide 24*21, manganese protoxide 1*15, magnesia 12*78,
water 10-59=100. B.B. same as for preceding.
Lophoite, Ogcoite, Helminthe belong here. Occur at St.
Gothard, at Greiner in the Tyrol, at Traversella in Pied-
mont, and many other places in Europe. Also at Steele's
Mine, N. C.
Leuchtenbergite is a proclilorite with the base almost solely magne-
sium.
Aphrosiderite, Metachlorite are near the above in composition.
Venerite is a pale-green earthy chlorite, from a magnetite mine in
Berks County, Pa.
Corundophilite is a chlorite near prochlorite in composition. Occurs
with corundum at Asheville, N. C.
Orochauite is from Grochau in Silesia.
Cromtedtite. Hexagonal, with perfect basal cleavage. Black. G.=
3'35. Consists mainly of silica, iron oxides, and water, with a little
manganese oxide. From Bohemia and Cornwall.
Thuringite. Another hydrous iron silicate, having G.=3'15-3-20,
from Thuringia, and also Hot Springs, Arkansas, and near Harper's
Ferry, on the Potomac. Patter sonite, from Union ville, Pa., is near it.
Margarita.— Emerylite. Diphanite. Clingmanite. Corundellite.
Trimetric. Foliated, mica-like. Laminae rather brittle.
Color white, grayish, reddish. Lustre of cleavage surface
320 DESCRIPTIONS OP MINERALS.
strong pearly and brilliant, of sides of crystals vitreous.
H.=3'5-4-5. G. = 2.99.
Composition. II2RA12 Oi2Si2= Silica 30*1, alumina 51.2,
lime 11 *6, soda 2-6, water 4*5 = 100. B.B. whitens and fuses
on the edges.
Obs. Often associated with corundum and diaspora. Oc-
curs in Asia Minor ; at Sterzing in the Tyrol ; in the
Urals ; in Village Green, and Unionville, Pa. ; in Buncombe
County, N". 0.; at Chester, Mass. Named from the Greek
margarites, a pearl.
Wittcoxite is near margarite. Dudleyite is an alteration product of
margarite.
Chloritoid.— Masonite. Phyllite. Ottrelite.
Monoclinic or triclinic. Cleavage basal, perfect. Also
coarse foliated massive ; and in thin disseminated scales
(phyllite or ottrelite). Brittle.
Color dark gray, greenish, to black. Lustre of cleavage
surface somewhat pearly.
Composition. FeAl 06Si + l aq= Silica 24'0, alumina 40 '5,
iron protoxide 284, water 7*1 = 100. B.B. becomes darker
and magnetic, but fuses with difficulty. Decomposed com-
pletely by sulphuric acid.
Obs. Found at Kossoibrod, Urals, with cyanite ; in Asia
Minor, with emery; at St. Marcel ; Ottrez, France (Ottre-
lite) ; Chester, Mass.; in Eh ode Island (Masonite) ; at
Brome and Leeds, Canada. Phyllite in scales character-
izes the " spangled mica slate " of Newport, R. I., and
Sterling, Goshen, etc., Mass.
Seybertite. Occurs in somewhat mica like, or thin foliated forms,
with perfect basal cleavage, and laminae brittle, the color reddish or
yellowish brown to copper-red. Analysis by Brush obtained Silica 20 24,
alumina 39 '13, iron sesquioxide 3 '27, magnesia 20*84, lime 13-69, water
1'04, potash and soda T43, zirconia 0'75=100'39, giving the quantiva-
lent ratio for protoxides, sesquioxides, silica, and water 6 : 9 : 5 : £. From
Amity, N. Y. ; Slatoust, Urals (Xanthophyllite) ; Fassa Valley (Bran-
disite and Disterrite).
IV. HYDROCARBON COMPOUNDS.
The following are the subdivisions here used.
I. SIMPLE HYDKOCABBOHS : Marsh-gas, Mineral oils, and
Mineral wax.
SIMPLE HYDROCARBONS. 321
II. OXYGENATED HYDROCARBONS : mostly resins.
III. ASPHALTUM AND MINERAL COALS.
I. SIMPLE HYDROCARBONS.
Marsh-Gas. — Light Carburetted Hydrogen
Colorless and inodorous gas in the pure state. Inflam-
mable, and burns with a yellow flame. Composition CII4=
Carbon 75, hydrogen 25 — 100.
Obs. This gas (mixed with more or less carbon dioxide
and nitrogen) often rises in bubbles through the waters of
marshes, whence its name ; and frequently it is discharged
from fissures into coal mines in large quantities, constituting
the fire-damp of the mine. Such natural discharges, called
blowers, sometimes continue for months. It is the cause of
the explosions in mines, a mixture of it with the atmo-
sphere exploding on the approach of the flame of a can-
dle. It destroys life both by the concussion occasioned, by
the exhaustion of the atmosphere of oxygen, and by the
production of carbon dioxide which takes place. The gas
which issues from the oil springs or wells of Western New
York (Fredonia), and Eastern Pennsylvania, is marsh-gas
mixed with other vapors of the Marsh-gas series. It is used
in some places for lighting houses, and even villages ; and
also for other purposes where heat is required.
The gas bubbling up from a marsh in Europe afforded
Websky Carbon dioxide 2-97, marsh-gas 43-36, nitrogen
53-67=100. The first of these ingredients is in fact one
of the more abundant results of decomposition, whetlter
vegetable or animal ; and the percentage is here small
because the gas is soluble in water, and because it readily
enters into combinations with the earthy ingredients of
plants.
Petroleum.
Mineral oils, varying in density from 0*60 to 0-85. Solu-
ble in benzine or camphene. They consist chiefly of liquids
of the Naphtha and Ethylene series. The composition of
the Naphtha or Marsh-gas series is expressed by the general
formula, CnH2n + 2, of which Marsh-gas is the first or
lowest term ; and that of the Ethylene series by the for-
mula, CnH2n=rCarbon 85'71, hydrogen 14-29-100. The
oils vary greatly in density from the lightest naphtha, too
DESCRIPTIONS OP MINERALS.
inflammable for use in lighting, to thick viscid fluids ; and
thence they pass by insensible gradations into asphaltum or
solid bitumen. The Marsh-gas series contains also gases,
of the composition C2H6 and C3H8 and these, in addition to
Marsh-gas, often exist in connection with petroleum.
Petroleum occurs in rocks of all ages, from the Lower
Silurian to the most recent ; in limestones, the more com-
pact sandstones, and shales ; but it is mostly obtained from
large cavities or caverns existing among the earth's strata.
Black shales and much bituminous coal afford it abundantly
when they are heated. But the oil obtained is not present
in these rocks, for when the rocks are treated with benzine,
the benzine takes up little or none ; instead, the rocks con-
tain an insoluble hydrocarbon, which yields the oil when
heat is applied.
In the United States the oil, or the hydrocarbon which
yields it, has been observed in beds of the Lower and Upper
Silurian, Devonian, Carboniferous, Triassic, Cretaceous, and
Tertiary eras. Surface oil springs also occur in many places,
as at Cuba, Alleghany County, N. Y., called Seneca Oil
Spring ; and on a large scale in Santa Barbara, Southern
California ; at Rangoon in Burmah, where there are about
100 wells ; on the peninsula of Apcheron, on the Caspian,
and elsewhere. Pliny mentions the oil spring of Agrigen-
tum, Sicily, and says that the liquid was collected and used
for burning in lamps, as a substitute for oil. Moreover he
distinguishes the oil from the lighter and more combustible
naphtha, a locality of which about the sources of the Indus,
^n Parthia," he mentions.
Petroleum is obtained chiefly at the present time from
more or less deeply-seated subterranean chambers or cavities
among the rock "strata, reached by boring. Being under
pressure of gas associated with it, and also, in many cases,
that also of water, it rises to the surface in the boring, and
sometimes makes a "spouting" well. As early as 1833,
Hildreth mentioned the discharge of oil with the waters
of the salt wells of the Little Kanawha valley ; and speaks
also of a well near Marietta, Ohio, which threw out at one
time, he says, 50 to 60 gallons of oil at " each eruption."
The mineral oil of the rocks has been formed through
the decomposition of animal and vegetable substances.
From the nature of the rocks which most abound in the
species of hydrocarbons that yield oil, it is evident that
SIMPLE HYDROCARBONS.
the rock material was in the state of a fine mud ; that
through this mud much vegetable or animal matter was
distributed, almost in the condition of an emulsion ; that
the stratum of this mud becoming afterward overlaid by
other strata, the decomposition of vegetable or animal mat-
ter went forward without the presence of atmospheric air,
or with only very little of it. Under such circumstances
either vegetable material or animal oils might be converted,
as chemists have shown, into mineral oil. Dry wood con-
sists approximately (excluding the ash and nitrogen) of 6
atoms of carbon to 9 of hydrogen, and 4 of oxygen. If now
all the oxygen of the Avood combines with a part of the car-
bon to form carbonic acid, and this 2 C02, thus made, is re-
moved, there will be left C4 II9 ; twice this, C8 H18, is the
formula of a compound of the Marsh-gas or Naphtha series.
Again animal oils, by decomposition under similar cir-
cumstances, produce like results. Removing from oleic
acid its oxygen, 02, and 1 of carbon— together equivalent to
1 of carbonic acid — there is left C17 H?4, which is an oil of
the Ethylene series ; and margaric acid would leave, in the
same way, C16 H34, or a combination of oils of the Marsh-gas
or Naphtha series. Warren and Storer have obtained from
the destructive distillation of a fish-oil, after its saponifica-
tion by lime, several compounds of the Marsh-gas series, be-
sides others of the Ethylene and Benzole series. The de-
compositions in nature may not have been as simple as those
in the above illustrations, yet the facts warrant the infer-
ence that the oils may have been derived either from vege-
table or animal matters. Fossil fishes are often found abun-
dantly in black oil-yielding shales, and Dr. Newberry has
suggested that fish-oil may be the most abundant source of
the oil and the oil-yielding hydrocarbons.
The oil which is collected in great cavities among the
earth's strata, as in Western Pennsylvania, is believed by
most writers on the subject to have come from underlying
rocks, such as the black oil-yielding shales. The heat pro-
duced in the rocks by the friction attending movements and
uplifts, is supposed to have been sufficient to have made the
oil from the hydrocarbon of the carbonaceous shale or other
rock, and co have caused it to ascend among the strata to
the cavities where it was condensed, and now is found by
boring.
The oils, exposed to the air and wind, undergo change in
324 DESCRIPTIONS OF MINERALS.
three ways. First : the lighter naphthas evaporate, leaving
the denser oils behind ; and, ultimately, the viscid bitumens,
or else paraffin, according as paraffin is present or not in
the native oil. At the naphtha island of Tschelekan in Per-
sia, there are large quantities of Neft-yil, as it is called,
which is nearly pure paraffin. The hot climate of the Cas-
pian is favorable for such a result. Secondly: ther emay
be a loss of hydrogen from its combination with the oxygen
of the atmosphere to form water, which escapes. Thus the
oils of the Naphtha series may change into those of the Ethy-
lene or Benzole series. Thirdly : there may be an oxidation
of the hydrocarbon of the oils, producing asphaltum or
more coal-like substances, like albertite.
The word naphtha is from the Persian, nafata, to exude ;
and petroleum from the Greek, petros, rock, and the Latin,
oleum, oil.
Hachettite.— Mountain Tallow, Hatchetine.
Like soft wax in appearance and hardness, of a yellowish-
white to greenish -yellow color.
Composition. Related to paraffin.
From the coal-measures of Glamorganshire in Wales.
Ozocerite is like wax or spermaceti in consistence. Soluble in ether.
The original was from Moldavia. Along with another wax -like sub-
stance, called Urpethite, it constitutes trie "mineral wax of Urpeth
Colliery." Zietrisikite is like beeswax, and is insoluble in ether ;
from Moldavia,
Elaterite. — Mineral Caoutchouc. Elastic Bitumen.
In soft flexible masses, somewhat resembling caoutchouc
or India rubber. Color brownish-black ; sometimes orange-
red by transmitted light. G. =0'9-r25. Composition: Car-
bon 85*5, hydrogen 13 '3 = 98 -8. It burns readily with a yel-
low flame and bituminous odor.
Obs. From a lead mine in Derbyshire, England, and a
coal mine at Montrelais. It has been found at Woodbury,
Ct., in a bituminous limestone.
Fichtelite and Hartite are crystallized hydrocarbons, of the Cam-
phene series. Branchite, Dinite, and Ixolyte are related to Hartite.
Konlite, Naphthalin, and Idrialite are native species of the Benzole
series. Aragotite, from California, is near Idrialite.
OXYGENATED HYDROCARBONS. 325
II. OXYGENATED HYDROCARBONS.
Amber.
In irregular masses. Color yellow, sometimes brownish
or whitish ; lustre resinous. Transparent to translucent.
H. = 2-2-o. G.= l-18. Electric by friction.
Amber is not a simple resin, but consists mainly (85 to 90
percent.) of a resin which resists all solvents, called Suc-
cinite, and two other resins soluble in alcohol and ether,
besides an oil, and 2% to G per cent, of Succinic acid.
Obs. Occurs in the loose deposits along coasts, especially
Tertiary strata, in masses from a very small size to that of
a man's head. In the Koyal Museum at Berlin, there is a
mass weighing 18 pounds. On the Baltic coast it is most
abundant, especially between Konigsberg and Memel. It
is met with at one place in a bed of bituminous coal ; it
also occurs on the Adriatic ; in Poland ; on the Sicilian
coast near Catania ; in France near Paris, in clay ; in China.
It has been found in the United States, at Gay Head,
Martha's Vineyard ; Camden, N. J. ; and at Cape Sable,
near the Magothy River, in Maryland.
It is supposed, with good reason, to be a vegetable resin
which has undergone some change while inhumed, a part
of which is due to acids of sulphur proceeding from decom-
posing pyrites or some other source. It often contains in-
sects, and specimens of this kind are so highly prized as
frequently to be imitated for the shops. Some of the insects
appear evidently to have struggled after being entangled in
the then viscous resin, and occasionally a leg or a wing is
found some distance from the body, having been detached
in the struggle for escape.
Amber is the electron of the Greeks ; from its becoming
electric so readily Avhen rubbed, it gave the name electricity
to science. It was also called succinum, from the Greek
succum, juice, because of its supposed vegetable origin.
It admits of a good polish and is used for ornamental
purposes, though not very much esteemed, as it is wanting
in hardness and brilliancy of lustre, and moreover is easily
imitated. It is much valued in Turkey for mouth-pieces
to pipes.
Copalite, or Mineral Copal, Walchowite, Ambrite (the New Zealand
resin), Euosmite, Scleretinite, Middletote are some of the names of
other fossil resins ; Geocerite, and Geomyricite, of wax -like oxygenated
species ; Guyaquittite, BathvUlite, Torbanite, lonite (from lone valley,
326 DESCRIPTIONS OF MINERALS.
California), of species not resinous in lustre ; Tasmanite and Dysodile,
of kinds containing several per cent, of sulphur. Wollongongite, from
Australia, is black, and looks like cannel coal.
III. ASPHALTUM AND MINERAL COALS.
Asphaltum.
Amorphous and pitch-like. Burning with a bright flame
and melting at 90° to 100° F. Soluble mostly or wholly in
camphene. It is a mixture of hydrocarbons, part of which
are oxygenated.
Obs. Asphaltum is met with abundantly on the shores of
the Dead Sea, and in the neighborhood of the Caspian. A
remarkable locality occurs on the island of Trinidad, where
there is a lake of it about a mile and half in circumference.
The bitumen is solid and cold near the shores; but gradu-
ally increases in temperature and softness toward the cen-
tre, where it is boiling. The appearance of the solidified
bitumen is as if the whole surface had boiled up in large
bubbles and then suddenly cooled. The ascent to the lake
from the sea, a distance of three quarters of a mile, is cov-
ered with the hardened pitch, on which trees and vegetation
flourish, and here and there, about Point La Braye, the
masses of pitch look like black rocks among the foliage. It
occurs also in South America about similar lakes in Peru,
where it is used for pitching boats ; and in California on
the coast of Santa Barbara. Large deposits occur in sand-
stone in Albania. It is also found in Derbyshire, and with
quartz and fluor in granite in Cornwall, and at many other
places.
Albertite.
Coal-like in hardness, but little soluble in camphene, and
only imperfectly fusing when heated ; but having the lustre
of asphaltum, and softens a little in boiling water. H. — 1-2.
G.= 1-097.
Fills fissures in the Subcarboniferous rocks near Hills-
borough, Nova Scotia, and supposed to have been derived
from the hydrocarbon of the adjoining rock, and to have
been oxidized at the time it was formed and filled the
fissure.
Orahamite is a related material from West Virginia, 20 miles south
of Parkersburg. ^H. =2. G. ^t'143. Soluble mostly in camphene,
but melts only imperfectly. An analysis afforded carbon 76 '45, hy-
drogen 7 '82, oxygen (with traces of nitrogen) 13 '40, ash 2 '26 =100,
MINERAL COAL. 327
MINERAL COAL.
Massive. Color black or brown ; opaque. Brittle or im-
perfectly sectile. H. =0-5-2-5. G. = 1 '2-1-80.
Composition. Carbon, with some oxygen and hydrogen,
more or less moisture, and traces also of nitrogen, besides
some earthy mineral which constitutes the ash. The car-
bon, or part of it, is in chemical combination with the
hydrogen and oxygen.
Coals differ in the amount of volatile ingredients given
off when heated. These ingredients are moisture, and hy-
drocarbon oils and gas, derived from the same class of
insoluble hydrocarbons that is the source of the oil of shales
and other rocks.
VARIETIES.
1. Anthracite. Anthracite (called also (/lance coal and
stone coal) has a high lustre, and is often iridescent. It is
quite compact and hard, and has a specific gravity from 1'3
to 1*75. It usually contains 80 to 93 per cent, of carbon,
with 4 to 7 of volatile matter ; the rest consisting of earthy
impurities. Burns with a feeble blue flame.
Those yielding the most volatile ingredients are called
free-burning anthracite.
2. Bituminous Coal. Bituminous coal varies much in the
amount of oil, coal-tar, or gas it yields when heated; and
there is a gradual passage in its varieties through semi-
anthracite to anthracite. It is of a black color, with the
powder black, but it is softer than anthracite, and less
lustrous. The specific gravity does not exceed 1*5. The
volatile ingredients constitute usually between 20 and 40
per cent.
Caking Coal includes that part of bituminous coal which
softens when heated and becomes viscid, so that adjoining
pieces unite into a solid mass. It burns readily with a
lively yellow flame, but requires frequent stirring to prevent
its agglutinating, and so clogging the fire. Non-caking coal
resembles the caking in appearance, but does not soften and
cake. The chemical difference between caking and non-
caking coal is not understood.
3. Cannel Coal is very compact and even in texture, with
little lustre, and breaks with a large conchoidal fracture. It
takes fire readily, and burns without melting to a clear yel-
328 DESCRIPTIONS OP MINERALS.
low flame, and has hence been used as candles — whence the
name. It affords when heated a large amount of mineral
oil, and may be used for its production. The volatile in-
gredients sometimes amount to 50 or 60 per cent. It is
often made into inkstands, snuff-boxes, and other similar
articles.
4. Brown Coal usually has a brownish-black color, and
contains 15 to 20 per cent, of oxygen, but much resembles
in appearance bituminous coal. The term brown coal is ap-
plied generally to any coal more recent in origin than the
era of the great coal beds of the world. The name lignite
has sometimes the same general application, though without
strict propriety. Lignite is the part of brown coal which
has the woody structure still apparent.
Jet resembles cannel coal, but is harder, of a deeper black
color, and has a much higher lustre. It receives a brilliant
polish, and is set in jewelry. It is the Gagates of Diosco-
rides and Pliny, a name derived from the river Gagas, in
Syria, near the mouth of which it was found, and the origin
of the term jet now in use.
Native Coke resembles somewhat artificial coke, but is
more compact, and some varieties of it afford a consider-
able amount of bitumen. It occurs at the Edgehill mines
near Richmond, Virginia, according to Genth, who attri-
butes its origin to the action of a trap eruption on bitumi-
nous coal.
It is now well established that mineral coal is mainly of
vegetable origin, and that the accumulations out of which
the coal beds were made were very similar in character,
though not in kinds of plants, to the peat beds of the pres-
ent day. Peat is vegetation which has undergone, in part,
the change to coal ; and in some cases it has become brown
coal. The conditions of change are somewhat different from
those of the beds of good coal, since, in the case of the peat,
the air has access, while in that of the coal the air was more
or less excluded by overlying strata ; and the more perfect
the exclusion, other things equal, the better the coal. As
the composition of mineral coal is closely related to that of
mineral oils", the explanation of the origin of the latter, given
on page 323, suffices to illustrate also the origin of the
former. With a less complete exclusion of the air, oxygen-
ated hydrocarbon compounds, like coal, would be a natural
result.
MINERAL COAL.
329
The following are a few analyses of coals, the moisture
excluded:
Carbon.
Hydr.
Oxyg.
Nitr.
Sulph.
Ash.
1
Anthracite Pennsylvania
90 45
2-43
2-45
4-67
0,
Anthracite Pennsylvania
92 59
263
1-61
092
225
3
Anthracite, South Wales . .
92 56
3 33
2-53
1 58
4
5
6
7
8
Caking Coal, Kentucky
Caking Coal, Nelsonville, O.
Caking Coal, South Wales. .
Caking Coal, Northumberl'd
Non-caking, Kentucky
74-45
73-80
82-56
78'69
77-89
4-93
579
536
6-00
5 42
1308
16-58
8-22
10-07
12-57
103
1-52
1-65
2-37
1-82
091
0-41
075
1-51
3-00
500
190
1-46
1-36
200
9
Non-caking " Black Coal," )
Ind )
82-70
4-77
939
1-62
0-45
1-07
10
11
19
Non-caking, Briar Hill, O. .
Non-caking, S. Staffordshire
Non-cakin0" Scotland . . .
78-94
7640
76'08
5-92
462
5 -81
11-50
17-43
13 33
1-58
209
0-56
0-55
1-23
1-45
155
1-96
13
14
Cannel Coal, Breckenridge .
Cannel Coal ^^igan
68-13
8007
6-49
5 53
5-83
8 10
2-27
2-12
2-48
1-50
1230
2-70
15
16
Cannel Coal, " Torbanite".
Albertite Nova Scotia
6402
86*04
8-90
8 '96
5-66
1-97
055
293
050
tTace
2032
o-io
17
Brown Coal Bovey
66-31
5 63
22-86
0-57
2-36
2-27
is
Brown Coal Wittenberg. . .
64-07
503
27-55
335
19
Peat light brown (imperfect)
50'86
5 -80
42-57
0*77
30
Peat dark bcown
59-47
6-52
31 51
2 51
?r1
Peat black
59-70
5-70
3304
1 56
00,
Peat black
59-71
5 27
32-07
2-59
The coal, No. 4, from "Roberts' Seam," Muhlenburg County, Ken-
tucky, has specific gravity =1 26 ; No. 9, from " Wolf Hill," Daviess
County, Indiana, has specific gravity =1 "275.
No. 13, the Breckenridge cannel, of Hancock County, Kentucky,
consists, when the ash is excluded, of Carbon 82 '36, hydrogen 7 '84,
oxygen 7 05, nitrogen 2 75, and the Bog-head cannel of Scotland, called
also torbanite, contains Carbon 8039, hydrogen 11-19, oxygen 7 '11, ni
trogen 1*31.
The " Mineral Charcoal " of coal beds differs little in composition
from ordinary bituminous coal ; there is less hydrogen and oxygen.
Rowney obtained, for that of Glasgow and Fifeshire, Carbon 82 "97,
74-71 ; hydrogen 3 34, 2 74; oxygen 759, 767 ; ash 6'08, I486. The
nitrogen is included with the oxygen ; it was 0'75 in the Glasgow char-
coal. Exclusive of the ash, the composition is Carbon 88/36, 87*78 ;
hydrogen 356, 321; oxygen 7 '28, 9' 01. It has a fibrous look, and
occurs covering the surfaces between layers of coal, and has been ob-
served in coal of all ages. It is soft and soils the fingers like char-
coal ; one variety of it is a dry powder.
330 DESCRIPTIONS OF MINERALS.
The following are average results, from many analyses :
Vol.
Fixed
Nos.
Sp. gr.
com-
Car-
Ash.
Analysis.
bust.
bon.
1
Pennsylvania anthracites. . . -j
7
16
1-59-1-61
1-39-1 -GO
3-92
5-70
89-77
88-23
6-31
6-07
Johnson.
Geol. Survey.
2
Pennsylvania semi-anthra- 1
cites f
11
1-33-1-45
9-98
82-86
7-16
Geol. Survey.
3
Pennsylvania semi-bitunii- 1
nous . f
6
1-30-1-41
16-85
72-95
10-20
Johnson.
4
Maryland semi-bituminous...
9
1-30-1-43
1550
7403
10-47
( Johnson and
j Geol. Survey.
5
Pennsylvania bituminous
10
28-35
65-18
6-47
Johnson.
6
Virginia bituminous . . .
11
i 29-1-45
29'88
59-06
11-06
Johnson.
7
Ohio bituminous
142
1-24-1-47
35-24
60-26
4-50
Wormley.
g
126 1'1Q 1'41
43-20
53-47
3'33
Cox
q
Illinois bituminous . . .
50
1-21 1-35
31 90
62-44
5'66
Blaney.
10
Iowa bituminous . ...
59
43-02
6-82
Emery.
The ordinary impurities of coal, making up its ash, are silica, a
little potash and soda, and sometimes alumina, with often oxide of
iron, derived usually from sulphide of iron ; besides, in the less pure
kinds, more or less clay or shale. The amount of ash does not ordina-
rily exceed 6 per cent., but it is sometimes 80 per cent. ; and rarely it
is less than 2 per cent. When not over 3 or 4 per cent, the whole may
have come from the plants which contributed the most of the material
of the coal, since the Lycopods have much alumina in the ash, and
the Equiseta much silica.
There is present in most coal traces of sulphide of iron (pyrite), suf-
ficient to give sulphur fumes to the gases from the burning coal, and
sometimes enough to make the coal valueless in metallurgical opera-
tions. Some thin layers are occasionally full of concretionary pyrite.
The sulphur was derived from the plants or from animal life in the
waters. Sulphur also occurs, in some coal beds, as a constituent of a
resinous substance ; and Wormley has shown that part of the sulphur
in the Ohio coals is in some analogous state, there being not iron
enough present to take the whole into combination.
The average amount of ash in eighty-eight coals from the southern
half of Ohio, according to Wormley, is 4'718 per cent.; in sixty-six
coals from the northern half, 5 '120 ; in all, from both regions, 4 '891 ;
or, omitting ten, having more than ten per cent, of ash, the average is
4"->8. In eleven Ohio cannels, the average amount of ash was 12'827.
The moisture in the Ohio coals, according to the analyses of Wormley,
varies from T10 to 910 per cent, of the coal.
Mineral coal occurs in extensive beds or layers, interstratified with
different rock strata. The associate rocks are usually clay shales (or
slaty beds) and sandstones ; and the sandstones are occasionally coarse
grit rocks or conglomerates. There are sometimes also beds of lime-
stone alternating with the other deposits.
Coal beds vary in thickness from a fraction of an inch to 40 feet.
The thickness of a bed may increase or diminish much in the course
of a few miles, or the coalmay become too shaly to work.
MINERAL COAL. 331
The areas of the "coal-measures" of the Carboniferous era, in
the United States, are as follows :
1. A small area in Rhode Island, continued northward into Massa-
chusetts.
2. A large area in Nova Scotia and New Brunswick, stretching east-
ward and westward from the head of the Bay of Fundy.
These two areas are now separated ; but it is probable that they
were once united along the region, now submerged, of the Bay of
Fundy and Massachusetts Bay.
3. The Alleghany Region, which commences at the north on the
southern borders of New York, and stretches south westward across
Pennsylvania, West Virginia, and Tennessee to Alabama, and west-
ward over part of Eastern Ohio, Kentucky, Tennessee, and a small
portion of Mississippi. To the north, the Cincinnati " uplift," or
the Silurian area extending from Lake Erie over Cincinnati to Ten-
nessee, forms the western boundary.
4. The Michigan coal area, an isolated area wholly confined within
the lower peninsula of Michigan.
5. The Eastern Interior area, covering nearly two-thirds of Illinois,
and parts of Indiana and Kentucky.
6. The Western Interior area, covering a large part of Missouri,
and extending north into Iowa, and South, with interruptions, through
Arkansas into Texas, and west into Kansas and Nebraska.
The Illinois and Missouri areas are connected now only through the
underlying Subcarbonif erous rocks of the age ; but it is probable that
formerly the coal fields stretched across the channel of the Missis-
sippi, and that the present separation is due to erosion along the
valley. Rocks of the Carboniferous period extend over large portions
of the Rocky Mountain area, but they are mostly limestones, and are
barren of coal.
The extent of the coal -bearing area of these Carboniferous regions
is approximately as follows :
Rhode Island area 500 square miles.
Alleghany area 59,000 square miles.
Michigan area 6,700 square miles.
Illinois, Indiana, West Kentucky 47,000 square miles.
Missouri, Iowa, Kansas, Arkansas, Texas 78,000 square miles.
Nova Scotia and New Brunswick 18,000 square miles.
The whole area in the United States is over 190,000 square miles,
and in North America about 208,000. Of the 190,000 square miles,
perhaps 120,000 have workable beds of coal.
Anthracite is the coal of Rhode Island, and of the areas in Central
Pennsylvania, from the Pottsville or Schuylkill coal field to the Lacka-
wanna field, while the coal of Pittsburg, and of all the great coal-
fields of the Interior basin, is bituminous, excepting a small area in
Arkansas. Anthracite belongs especially to regions of upturned
rocks, and bituminous coal to those where the beds are little disturbed.
In the area between the anthracite region of Central Pennsylvania
and the bituminous of Western, and farther south, the coal is semi-
bituminous, as in Broad Top, Pennsylvania, and the Cumberland coal
field in Western Maryland, the volatile matters yielded by it being 15
332 DESCRIPTIONS OP MINERALS.
to 20 per cent. The more western parts of the anthracite coal fields
afford the free-burning anthracite, or semi-anthracite, as at Trevor-
ton, Shamokin, and Birch Creek.
The coal-formation of the Carboniferous age in Europe has great
thickness of rocks and coal in Great Britain, much less in Spain,
France, and Germany, and a large surface, with little thickness of
coal, in Russia. It exists, also, and includes workable coal-beds, in
China, and also in India and Australia ; but part of the formation in
these latter regions may prove to be Permian. No coal of this era has
yet been found in South America, Africa, or Asiatic Russia. The pro-
portion of coal beds to area in different parts of Europe has teen
stated as follows : in France, l-100th of the surface ; in Spain, l-50th;
in Belgium, l-20th ; in Great Britain, 1-lOth. But, while the coal
area in Great Britain is about 12,000 square miles, that of Spain is
4,000, that of France about 2,000, and that of Belgium 518.
Mineral coal of later age than the true Carboniferous era occurs in
various parts of the world. Triassic or Jurassic coal, of the bitumi-
nous variety, occurs in thick workable beds in the vicinity of Rich-
mond, Virginia, and also in the Deep River and Dan River regions
in North Carolina ; and it constitutes very valuable and extensive
beds also in India. In England, at Brora in Sutherlandshire, there
is a bed of Jurassic coal. Coal of the Cretaceous and Tertiary eras
constitutes important beds in various parts of the Rocky Mountain
region, in the vicinity of the Pacific Railroad and elsewhere. Some
of the prominent localities are : In Utah, at Evanston and Coalville
(in the valley of Weber River), etc.; in Wyoming, at Carbon, 140
miles from Cheyenne ; at Hallville, 142 miles farther west ; at Black
Butte Station, on Bitter Creek ; on Bear River, etc. ; in the Uintah
Basin, near Brush Creek, 6 miles from Green River ; in Colorado, at
Golden City, 15 miles west of Denver, on Ralston Creek, Coal Creek,
S. Boulder Creek and elsewhere ; in New Mexico, at the Old Placer
Mines in the San Lazaro Mountains, etc. The coal is of the bitumi-
nous or semibituminous kind, related to brown coal, and is often im
properly called lignite. That of Evanston (where the bed is 26 feet
thick) afforded Prof. P. Frazier, Jr. , 37-38 per cent, of volatile sub-
stances, 5-6 of water, 7-8 of ash, and 49-50 of fixed carbon. At the
Old Placer Mines, New Mexico, there is anthracite, according to Dr.
J. LeConte, affording 88 to 91 per cent, of fixed carbon ; specimens
from there, analyzed by Frazier, were semibituminous, affording
68-70 per cent, of fixed carbon, 20 per cent, of volatile substances, and
about 3 per cent, of water. The region of the Old Placer Mines is one
of upturned and altered rocks, like the anthracite region of Pennsyl-
vania. Other similar beds occur toward the Pacific coast, the most
valuable of them in Washington Territory, Seattle and Belli ngham
Bay, and on Vancouver and adjacent islands in British Columbia.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 333
I. CATALOGUE OP AMERICAN LOCALL
TIES OF MINERALS.
THE following catalogue of American localities of minerals is intro-
duced as a Supplement to the Descriptions of Minerals. Its object is
to aid the mineralogical tourist in selecting his routes and arranging
the plan of his journeys. Only important localities, affording cabinet
specimens, are in general included ; and the names of those miner ah
which are obtainable in good specimens are distinguished by italics.
When a name is not italicized the mineral occurs only sparingly or of
poor quality. When the specimens to be procured are remarkably
good, an e'xclamation mark (!) is added, or two of those marks (I !)
when the specimens are quite unique.
MAINE.
ALBANY. — Beryl! green and black tourmaline, feldspar, rose quartz,
rutile.
AROOSTOOK. — Red hematite.
AUBURN. — Lepidolite, hebronite, green tourmaline.
BATH. — Vesuvianite, garnet, magnetite, graphite.
BETHEL. — Cinnamon garnet, calcite, sphene, beryl, pyroxene, horn-
blende, epidote, graphite, talc, pyrite, arsenopyrite, magnetite, wad.
BINGHAM. — Massive pyrite, galenite, blende, andalusite.
BLUE HILL BAY. — Arsenical iron, molybdenite! galenite, apatite!
fluoritef black tourmaline (Long Cove), black oxide of manganese
(Osgood's farm), rhodonite, bog manganese, wolframite.
BOWDOIN. — Rose quartz.
BOWDOINHAM. — Beryl, molybdenite.
BRUNSWICK. — Green mica, garnet ! black tourmaline ! molybdenite,
epidote, calcite, muscomte, feldspar, beryl.
BUCKFIELD.— Garnet (estates of Waterman and Lowe), muscomte!
tourmaline ! magnetite.
CAMDAGE FARM. — (Near the tide mills), molybdenite, wolframite.
CAMDEN. — Macle, galenite, epidote, black tourmaline, pyrite, talc,
magnetite.
CARMEL (Penobscot Co.) — Stibnite, pyrite, made.
CORINN A. — Pyrite, arsenopyrite.
DEER ISLE. — Serpentine, verd-antique, asbestus, diallage.
DEXTER. — Galenite, pyrite, blende, chalcopyrite, green talc.
DIXFIELD. — Native copperas, graphite.
EAST WOODSTOCK. — Muscovite.
FARMINGTON. — (Norton's Ledge), pyrite, graphite, garnet, staurolite.
FREEPORT. — Rose quartz, garnet, feldspar, scapolite, graphite, mu*
tovite.
FRYEBURG.— Garnet, beryl.
GEORGETOWN.— (Parker's Island), beryl! black tourmaline.
334 SUPPLEMENT TO DESCRIPTIONSJOF SPECIES.
GREENWOOD. — Graphite, black manganese, "beryl! arsenopyrite,
cassiterite, mica, rose quartz, garnet, corundum, albite, zircon, molyb-
denite, magnetite, copperas.
HEBRON. — Cassiterite, arsenopyrite, idocrase, lepidolite, hebronite,
rubellite ! indicolite, green tourmaline, mica, beryl, apatite, albite, chil-
drenite, cookeite.
JEWELL'S ISLAND. — Pyrite.
KATAHDIN IRON WORKS. — Bog-iron ore, pyrite, magnetite, quartz.
LITCHFIELD. — Sodalite, cancrinite, elceolite, zircon, spodumene, mus-
covite, pyrrliotite.
LUBEC LEAD MINES. — Galenite, cJialcopyrite, blende.
MACHIASPORT. — Jasper, epidote, laumontite.
MADAWASKA SETTLEMENTS. — Vivianite.
MINOT. — Beryl, smoky quartz.
MONMOUTH. — Actinolite, apatite, elceolite, zircon, staurolite, plumose
mica, beryl, rutile.
MT. ABRAHAM. — Andalusite, staurolite.
NORWAY. — Chrysoberyl! molybdenite, beryl, rose quartz, orthoclase,
cinnamon garnet.
ORR'S ISLAND. — Steatite, garnet, andalusite.
OXFORD. — Garnet, beryl, apatite, wad, zircon, muscovite, orthoclase.
PARIS. — Green! red! black, and blue tourmaline! mica! lepidolite!
feldspar, albite, quartz crystals! rose quartz, cassiterite, amblygonite,
zircon, brookite, beryl, smoky quartz, spodumene, cookeite, leucopy-
rite.
PARSONSFIELD. — Vesuvianite f yellow garnet, pargasite, adularia,
scapolite, galenite, blende, chalcopyrite.
PERU. — Crystallized pyrite.
PHIPPSBURG. — Yellow garnet ! manganesian garnet, vesuvianite, par-
gasite, axinite, laumontite ! chabazite, an ore of cerium ?
POLAND. — Vesuvianite, smoky quartz, cinnamon garnet.
PORTLAND. — Prehnite, actinolite, garnet, epidote, amethyst, calcite.
POWNAL. — Black tourmaline, feldspar, scapolite, pyrite, actinolite,
apatite, rose quartz.
RAYMOND. — Magnetite, scapolite, pyroxene, lepidolite, tremolite, horn-
blende, epidote, orthoclase, yellow garnet, pyrite, vesuvianite.
ROCKLAND. — Hematite, tremolite, quartz, wad, talc.
RUMFORD. — Yellow garnet, vesuvianite, pyroxene, apatite, scapolite.
RUTLAND. — Allanite.
SANDY RIVER. — Auriferous sand.
SANFORD, York Co.— Vesuvianite f albite, calcite, molybdenite, epi-
dote, black tourmaline, labradorite.
SEARSMONT. — Andalusite, tourmaline.
SOUTH BERWICK.— Macle.
STANDISH. — Columbite !
STREAKED MOUNTAIN. — Beryl! black tourmaline, mica, garnet.
THOM ASTON. — Calcite, tremolite, Jiornblende, sphene, arsenical iron
(Owl's Head), black manganese (Dodge's Mountain), thomsonite, talc,
blende, pyrite, galenite.
TOPSHAM.— Quartz, galenite, blende, tungstite? beryl, apatite,
molybdenite, columbite.
WALES. — ; Axinite in boulder, alum, copperas.
WATERVILLE. — Crystallized pyrite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 335
WINDHAM (near the bridge). — Staurolite, spodumene, garnet, beryl,
amethyst, cyanite, tourmaline.
WINSLOW. — Cassiterite.
WINTHROP.- -Staurolite, pyrite, hornblende, garnet, copperas.
WOODSTOCK. — Graphite, hematite, prehnite, epidote, calcite.
YORK. — Beryl, vivianite, oxide of manganese.
NEW HAMPSHIRE.
ACWORTH. — Beryl!! mica! tourmaline, orthodase, albite, rose
quartz, columbitef cyanite, autunite.
ALSTEAD. — Mica! ! albite , black tourmaline, molybdenite, andalu-
site, Staurolite.
AMHERST. — Vesumanite, yellow garnet, pargasite, calcite, amethyst.
BARTLETT. — Magnetite, hematite, smoky quartz.
BATH. — Galenite, chalcopyrite.
BEDFORD. — Tremolite, epidote, graphite, mica, tourmaline, alum,
quartz.
BELLOWS FALLS. — Cyanite, Staurolite, wavellite.
BRISTOL. — Graphite.
CAMPTON. — Beryl !
CANAAN. — Gold in pyrite, garnet.
CHARLESTON. — Staurolite made, andalusite made, bog-iron ore,
prehnite, cyanite.
CORNISH. — Stibnite, tetrahedrite, rutUein quartz! (rare), Staurolite.
CROYDEN. — lolite! chalcopyrite, pyrite, pyrrhotite, blende.
ENFIELD. — Gold, galenite. Staurolite, green quartz.
FRANCESTON. — Soapstonc, arsenopyrite, quartz crystals.
FRANCONIA. — Hornblende, Staurolite ! epidote ! zoisite, hematite,
magnetite, black and red manganesian garnets, arsenopyrite (danaite),
chalcopyrite, molybdenite, prehnite, green quartz, malachite, azurite.
GILFORD (Gunstock Mt.) — Magnetic iron ore, native "lodestone."
GILMANTOWN. — Tremolite, epidote, muscovite, tourmaline, limonite,
red and yellow quartz crystals.
GOSHEN. — Graphite, black tourmaline.
GRAFTON. — Mica! (extensively quarried at Glass Hill, 2 m. S. of
Orange Summit), albite ! blue, green, and yellow beryls ! (i m. S. of O.
Summit), tourmaline, garnets, triphylite, apatite, fluorite.
GRANTHAM. — Gray Staurolite!
GROTON. — Arsenopyrite, blue beryl, muscovite crystals.
HANOVER. — Garnet, black tourmaline, quartz, cyanite, labradoritet
epidote, anorthite.
HAVERHILL. — Garnet! arsenopyrite, native arsenic, galenite, blende,
pyrite, chalcopyrite, magnetite, marcasite, steatite.
HILLSBORO' (Campbell's Mountain). — Graphite.
HINSDALE. — Rhodonite, black oxide of manganese, molybdenite, in-
dicolite, black tourmaline.
JACKSON. — Drusy quartz, tin ore, arsenopyrite, native arsenic, fluo
rite, apatite, magnetite, molybdenite, wolframite, chalcopyrite.
JAFFREY (Monadnock Mt.) — Cyanite, limonite.
KEENE. — Graphite, soapstone, milky quartz, rose quartz.
LANDAFF. — Molybdenite, lead and iron ores.
336 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
LEBANON. — Bog-iron ore, arsenopyrite, galenite, magnetite, pyrito.
LISBON. — Staurolite, black and red garnets, magnetite, hornblende,
epidote, zoisite, hematite, arsenopyrite, galenite, gold, ankerite.
LITTLETON. — Ankerite, gold, bornite, chalcopyrite, malachite, me-
naccanite, chlorite.
LYMAN. — Gold, arsenopyrite, ankerite, dolomite, galenite, pyrite,
copper, pyrrhotite.
LYME. — Cyanite (N. W. part), Hack tourmaline, rutile, pyrite, chal-
copyrite (E. of E. village), stibnite, molybdenite, cassiterite.
MADISON. — Galenite, blende, chalcopyrite, limonite.
MERRIMACK. — Rutile! (in gneiss nodules in granite vein).
MlDDLETO WN. — EutiU.
MONADNOCK MOUNTAIN. — Andalusite, hornblende, garnet, graphite,
tourmaline, orthoclase.
MOOSILAUKE MT. — Tourmaline.
MOULTONBOROUGH (Red Hill).— Hornblende, bog ore, pyrite, tour-
maline.
NEWINGTON. — Garnet, tourmaline.
NEW LONDON.— Beryl, molybdenite, muscovite crystals.
NEWPORT. — Molybdenite .
ORANGE. — Blue beryls! Orange Summit, chrysoberyl, mica(W. side
of mountain), apatite, galenite, limonite.
ORFORD. — Brown tourmaline (now obtained with difficulty), steatite,
rutile, cyanite, brown iron ore, native copper, malachite, galenite,
garnet, graphite, molybdenite, pyrrhotite, melaconite, chalcocite, ripi-
dolite.
PELHAM. —Steatite.
PIERMONT. — Micaceous iron, barite, green, white, and brown mica,
apatite, titanic iron.
PLYMOUTH. — Columbite, beryl.
RICHMOND.— lolite! rutile, steatite, pyrite, anthophyllite, talc.
RYE. — Chiastolite.
SADDLEBACK MT. — Black tourmaline, garnet, spinel.
SHELBURNE. — Galenite, black blende, chalcopyrite, pyrite, pyroluslte.
SPRINGFIELD. — Beryls (very large, eight inches diameter), manga-
nesian garnets ! black tourmaline ! in mica slate, albite, mica.
SULLIVAN. — Tourmaline (black) in quartz, beryl.
SURREY. — Amethyst, calcite, galenite, limonite, tourmaline.
TAMWORTH (near White Pond). —Galenite.
UNITY (estate of James Neal). — Copper and iron pyrites, chlorophyl-
lite, green mica, radiated actinolite, garnet, titaniferous iron ore, mag-
netite, tourmaline.
WALPOLE (near Bellows Falls). — Made, staurolite, mica, graphite.
WAR E. — Graphite.
WARREN. — Chalcopyrite, blende, epidote, quartz, pyrite, tremolite,
galenite, rutile, talc, molybdenite, cinnamon stone! pyroxene, horn-
blende, beryl, cyanite, tourmaline (massive) vesuvianite.
WATER VILLE. — Labradorite, chrysolite.
WESTMORELAND (south part).— Molybdenite! apatite! blue feldspar,
"bog manganese (north village), quartz, fluorite, chalcopyrite, molybdite.
WHITE MTS. (Notch near the "Crawford House"). — Green octa-
hedral fluorite, quartz crystals, black tourmaline, chiastolite, beryl,
calcite, amethyst, amazon-stone.
CATALOGUE OF AMERICAN LOCALITIES OP MINERALS. 337
WILMOT. — Beryl.
WINCHESTER. — Pyrolusite, rhodonite, rhodochrosite, psilomelane,
magnetite, granular quartz, spodumene.
VERMONT.
ADDTSON. — Iron sand, pyrite.
ATHENS.— Steatite, rhomb spar, actinolite, garnet.
BALTIMORE. — Serpentine, pyrite !
BELVIDERE.— Steatite, chlorite.
BENNINGTON. — Pyrolusite, brown iron ore, pipe clay, yellow ochre.
BERKSHIRE. — Epidote, hematite, magnetite.
• BETHEL.— Actinolite! talc, chlorite, octahedral iron, rutile, brown
spar in steatite.
BRANDON. — Braunite, pyrolusite, psilomelane, limonite, lignite,
kaolinite, statuary marble ; graphite, chalcopyrite.
BRATTLEBOROUGH. — Black tourmaline in quartz, mica, zoisite, ru-
tile, actinolite, scapolite, spodumene, roofing slate.
BRIDGEWATER. — Talc, dolomite, magnetite, steatite, chlorite, gold,
native copper, blende, galenite, blue spinel, chalcopyrite.
BRISTOL. — Rutile, limonite, manganese ores, magnetite.
BROOKFIELD. — Arsenopyrite, pyrite.
CABOT. — Garnet, staurolite, hornblende, albite.
CASTLETON. — Roofing slate, jasper, manganese ores, chlorite.
CAVENDISH.— Garnet, serpentine, talc, steatite, tourmaline, asbestus,
tremolite.
CHESTER. — Asbestus, feldspar, chlorite, quartz.
CHITTENDEN. — Psilomelane, pyrolusite, brown iron ore, hematite
and magnetite, galenite, iolite.
COLCHESTER. —Brown iron ore, iron sand, jasper, alum.
CORINTH. — Chalcopyrite (has been mined), pyrrhotite, pyrite, rutile.
COVENTRY. — Rhodonite.
CRAFTSBURY.— Mica in concentric balls, calcite, rutile.
DERBY. ^-Mica (adamsite).
DUMMERSTON. — Rutile, roofing slate.
FAIR HAVEN.— Roofing slate, pyrite.
FLETCHER.- — Pyrite, magnetite, acicular tourmaline.
GRAFTON. — The steatite quarry referred to Graf ton is properly in
Athens ; quartz, actinolite.
GUILFORD. — Scapolite, rutile, roofing slate.
HARTFORD. — Calcite, pyrite/ cyanite, quartz, tourmaline.
IRASBURGH. — Rhodonite, psilomelane.
JAY. — Ghromite, serpentine, amianthus, dolomite.
LOWELL. — Picrosmine, amianthus, serpentine, talc, chlorite.
MARLBORO'. — Rhomb spar, steatite, garnet, magnetite, chlorite.
MIDDLEBURY. — Zircon.
MIDDLESEX.— Rutile ! (exhausted).
MONKTOWN. — Pyrolusite, brown iron ore, pipe clay, feldspar.
MORETOWN. — Smoky quartz! steatite, talc, wad, rutile, serpentine.
MORRISTOWN. — Galenite.
MOUNT HOLLY. — Asbestus, chlorite.
NEW FANE.— Glassy and asbestiform actinolite, steatite, green quarto
338 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
(called chrysoprase at the locality), chalcedony, drusy quartz, garnet,
chromic and titanic iron, rhomb spar, serpentine, rutile.
NORWICH. — Actinolite, feldspar, brown spar> in talc, cyanite, zoisite,
chalcopyrite, pyrite.
PITTSFORD. — Brown iron ore, manganese ores, statuary marble!
PLYMOUTH. — Siderite, magnetite hematite, gold, galenite.
PLYMPTON. — Massive hornblende.
PUTNEY. — Fluorite, limonite, rutile, and zoisite, in boulders,- stau-
rolite.
READING. — Glassy actinolite in talc.
READSBORO'. — Glassy actinolite, steatite, hematite.
RIPTON. — Brown iron ore, augite in boulders, octahedral pyrite.
ROCHESTER. — Rutile, hematite eryst., magnetite in chlorite slate.
ROCKINGHAM (Bellows Falls). — Cyanite, indicolite, feldspar, tour-
maline, fluorite, calcite, prehnite, staurolite.
ROXBURY. — Dolomite, talc, serpentine, asbestus, quartz.
RUTLAND. — Magnesite, white marble, hematite, serpentine, pipe clay.
SALISBURY. — Brown iron ore.
SHARON. — Quartz crystals, cyanite.
SHOREHAM. — Pyrite, black marble, calcite.
SHREWSBURY. — Magnetite and chalcopyrite.
STIRLING. — Chalcopyrite, talc, serpentine.
STOCKBRIDGE. — Arsenopy rite, magnetite.
STRAFFORD. — Magnetite and chalcopyrite (has been worked), native
copper, hornblende, copperas.
THETFORD. — Blende, galenite, cyanite. chrysolite in basalt, pyrrho-
tite, feldspar, roojing slate, steatite, garnet.
TOWNSHEND. — Actinolite, black mica, talc, steatite, feldspar.
TROY. — Magnetite, talc, serpentine, picrosmine, amianthus, steatite,
one mile southeast of village of South Troy, on the farm of Mr. Pierce,
east side of Missisco, chromite, zaratite.
VERSHIRE. — Pyrite, chalcopyrite, tourmaline, arsenopyrite, quartz.
WARDSBORO'. — Zoisite, tourmaline, tremolite, hematite.
WARREN. — Actinolite, magnetite, wad, serpentine.
WATERBURY. — Arsenopyrite, chalcopyrite, rutile, quartz, serpen-
tine.
WATERVILLE. — Steatite, actinolite, talc.
WEATHERSFIELD. — Steatite, hematite, pyrite, tremolite.
WELLS' RIVER. — Graphite.
WESTFIELD. — Steatite, chromite, serpentine.
WESTMINSTER. — Zoisite in boulders.
WINDHAM. — Glassy actinolite, steatite, garnet, serpentine.
WOODBURY. — Massive pyrite.
WOODSTOCK. — Quartz crystals, garnet, zoisite.
MASSACHUSETTS.
ALFORD. — Galenite, pyrite.
ATHOL. — Allanite, fibrolite (?), epidote ! babingtonite ?
AUBURN. — Masonite.
JSKTXKE,.— Rutile ! mica, pyrite, beryl, feldspar, garnet.
GREAT BARRINGTON. — Tremolite.
BEDFORD. — Garnet.
CATALOGUE OP AMERICAN LOCALITIES OP MINERALS. 339
BELCHERTON. —All anite.
BERNARDSTON. — Magnetite.
BEVERLY. — Columbite, green feldspar, cassiterite.
BLANFORD. — Serpentine, anthophyllite, actinolite ! chromite, cyanite.
rose quartz in boulders.
BOLTON.— Scapolite f petalite, sphene, pyroxene, nuttalite, diopside,
boltonite, apatite, magnesite, rhomb spar, allanite, yttrocerite ! spinel.
BOXBOROUGH. — Scapolite, spinel, garnet, augite, actinolite, apatite.
BRIGHTON. — Asbestus.
BRIMFIELD (road leading to Warren). — lolite, adularia, molybdenite,
mica, garnet.
CARLISLE. — Tourmaline, garnet! scapolite, actinolite.
CHARLESTOWN. — Prehnite, laumontite, stilbite, chabazite, quartz
crystals, melanolite.
CHELMSFORD. — Scapolite (chelmsfordite), chondrodite, Hue spinel,
amianthus! rose quartz.
CHESTER. — Hornblende, scapolite, zoisite, spondumene, indicolite,
apatite, magnetite, chromite, stilbite, heulandite, analcite and cha-
bazite. At the Emery Mine, Chester Factories. — Corundum, marga-
rite, diaspore, epidote, corundophilite, chloritoid, tourmaline, menac-
canite ! rutile, biotite, indianite ? andesite ? cyanito, amesite.
CHESTERFIELD. — Blue, green, and red tourmaline, cleavelandite
(albite), lepidolite, smoky quartz, microlite, spodumene, cyanite, apatite,
rose beryl, garnet, quartz crystals, staurolite, cassiterite, tolumbite,
zoisite, uranite, brookite (eumanite), scheelite, anthophyllite, bornite.
CON WAY. — Pyrolusite, fluorite, zoisite, rutile!! native alum, gale-
nite.
CUMMINGTON.— Rhodonite! cummingtonite (hornblende), marcasite,
garnet.
DEERFIELD. — Chabazite, heulandite, stilbite, amethyst, carnelian,
chalcedony, agate.
FITCHBURG (Pearl Hill).— Beryl, staurolite! garnets, molybdenite.
FOXBOROL GH. —Pyrite, anthracite.
FRANKLIN. — Amethyst.
GOSHEN. — Mica, alfoite, spondumene! blue and green tourmaline,
beryl, zoisite, smoky quartz, columbite, tin ore, galenite, beryl (go-
shenite), cymatolite.
GREENFIELD (in sandstone quarry, half mile east of village). — Allo-
phane, white and greenish.
HATFIELD. — Barite, galenite, blende, chalcopyrite.
HAWLEY. — Micaceous iron, massive pyrite, magnetite, zoisite.
HEATH. — Pyrite, zoisite.
HINSDALE. — Brown iron ore, apatite, zoisite.
HUBBARDSTON. — Massive pyrite.
HUNTINGTON (name changed from Norwich). — Apatite! Hack tour*
maline, beryl, spodumene ! triphylite (altered), blende, quartz crystals,
cassiterite.
LANCASTER.— Cyanite, chiastolite! apatite, staurolite, pinite, and*
lusite.
LEE. — Tremolite! sphene! (east part).
LEVERETT. — Barite, galenite, blende, chalcopyrite.
LEYDEN. — Zoisite, rutile.
LTTTLEFIELD. — Spinel, scapolite, apatite,
340 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
LYNNFIELD. — Magnesite on serpentine.
M ENDON. — Mica ! chlorite.
MIDDLEFIELD. — Glassy actinolite, rhomb spar, steatite, serpentine,
feldspar, drusy quartz, apatite, zoisite, nacrite, chalcedony, talc!
deweylite.
MILBURY. — Vermiculite.
NEW BRAINTREE. — Black tourmaline.
NEWBURY. — Serpentine, chrysotile, epidote, massive garnet, side-
rite.
NEWBURYPORT.— Serpentine, nemalite, uranite. — Argentiferous ga
lenite, tetrahedrite, chalcopyrite, pyrargyrite, etc.
NORTHFIELD. — Columbite, fibrolite, cyanite.
NORWICH.— See HUNTINGTON.
PALMER (Three Rivers).— Feldspar, calcite.
PELHAM. — Asbestus, serpentine, quartz crystals, beryl, molybdenite,
green hornstone, epidote, amethyst, corundum, vermiculite (pelhamite).
PLAINFIELD. — (Jummingtonite, pyrolusite, rhodonite.
RICHMOND. — Brown iron ore, gibbsite ! allophane.
ROCKPORT. — Danalite, cryophyllite, annite, cyrtolite (altered zircon),
green and white orthoclase, fergusonite.
ROWE. — Epidote, talc.
SOUTH ROYALSTON.— y&ery? / / (now obtained with great difficulty),
mica! ! feldspar ! allanite. Four miles beyond old loc., on farm oi
Solomon Heywood, mica ! beryl ! feldspar ! menaccanite.
RUSSEL. — Schiller spar (diallage ?), mica, serpentine, beryl, galenite,
chalcopyrite.
SALEM. — In a boulder, cancrinite, sodalite, elaeolite.
SHEFFIELD. —Asbestus, pyrite, native alum, pyrolusite, rutile.
SHELBURNE. — Rutile.
SHUTESBURY (east of Locke's Pond). — Molybdenite.
SOUTHAMPTON. — Galenite, cerussite, anglesite, wulfenite, fluorite,
barite, pyrite, chalcopyrite, blende, phosgenite, pyromorphite, stolzite,
chrysocolla.
STERLING. — Spodumene, chiastolite, siderite, arsenopyrite, blende,
galenite, chalcopyrite, pyrite, sterlingite (damourite).
STONEH AM. — Nephrite.
STURBRIDGE. — Graphite, garnet, apatite, bog ore.
SWAMPSCOT. — Orthite, feldspar.
TAUNTON (one mile south). — Paracolumbite (titanic iron).
TURNER'S FALLS (Conn. River). — Chalcopyrite, prehnite, chlorite,
siderite, malachite.
TYRINGHAM. — Pyroxene, scapolite.
UXBRIDGE. — Galenite.
WARWICK. — Massive garnet, radiated black tourmaline, magnetite,
beryl, epidote.
WASHINGTON. — Graphite.
WESTFIELD. — Schiller spar (diallage), serpentine, steatite, cyanite,
scapolite, actinolite.
WESTFORD. — Andalusite !
WEST HAMPTON. — Galenite, argentine, pseudomorphous quartz.
WEST SPRINGFIELD. — Prehnite, ankerite, satin spar, celestite.
WEST STOCKBRIDGE. — Limonite, fibrous pyrolusite, siderite.
WHATELY. — Native copper, galenite.
CATALOGUE OP AMERICAN LOCALITIES OF MINERALS. 341
WILLIAMSBURG. — Zoisite, pseudomorphous quartz, apatite, rose and
smoky quartz, galenite, pyrolusite, chalcopyrite.
WILLIAMSTOWN.— Cryst. quartz.
WINDSOR. — Zoisite, actinolite, rutile!
WORCESTER. — Arsenopy rite, idocrase, pyroxene, garnet, amianthus,
bucholzite, siderite, galenite.
WORTHIN GTON. — Cyanite.
ZOAR.— Bitter spar, talc.
RHODE ISLAND.
BRISTOL. — A methyst.
COVENTRY. — Mica, tourmaline.
CRANSTON. — Actinolite in talc, graphite, cyanite, mica, melanterite.
CUMBERLAND. — Manganese, epidote, actinolite, garnet, titaniferous
Iron, magnetite, red hematite, chalcopyrite, bornite, malachite, azu-
rite, calcite, apatite, feldspar, zoisite, mica, quartz crystals, ilvaite.
DIAMOND HILL. - Quartz crystals, hematite.
FOSTER. — Cyanite, hematite.
GLOUCESTER. — Magnetite in chlorite slate, feldspar.
JOHNSTON. — Talc, brown spar, calcite, garnet, epidote, pyrite, he-
matite, magnetite, chalcopyrite, malachite, azurite.
NATIC.— See WARWICK.
NEWPORT. — Serpentine, quartz crystals.
PORTSMOUTH. — Anthracite, graphite, asbestus, pyrite, chalcopyrite.
SMITHFIELD. — Dolomite, calcite, bitter spar, siderite, nacrite, serpen-
tine (bowenite), tremolite, asbestus, quartz, magnetic iron in chlorite
slate, talc ! octahedrite, feldspar, beryl.
VALLEY FALLS.— Graphite, pyrite, hematite.
WARWICK (Natic village). — Masonite, garnet, graphite.
W ESTERLY. — Menaccanite.
WOONSOCKET. — Cyanite.
CONNECTICUT
» BERLIN. — Barite, datolite, blende, quartz crystals.
BOLTON. — Staurolite, chalcopyrite.
BRADLEYVILLE (Litchfield). — Laumontite.
BRISTOL. — Chalcocite, chalcopyrite, barite, bornite, dllophane, pyro-
orphite, calcite, malachite, galenite, quartz.
BROOKFIELD.— Galenite, calamine, blende, spodumene, pyrrhotite.
CANAAN. — Tremolite and white augite ! in dolomite, canaanite (mas-
sive pyroxene).
CHATHAM. — Arsenopyrite, smaltite, cloanthite (chathamite), scoro
dite, niccolite, beryl, erythrite.
CHESHIRE.— Barite! chalcocite, bornite, malachite, kaolin, natrolite,
prehnite, chabazite, datolite.
CHESTER. — Sillimanitef zircon, epidote.
CORNWALL.— Graphite, pyroxene, actinolite, sphene, scapolite.
DANBURY. — Danburite, oligoclase, moonstone, brown tourmaline,
orthoclase, pyroxene, parathorite.
FARMINGTON.— Prehnite, chabazite, agate, native copper ; in trap,
diabantite.
342 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
GRANBY. — Green malachite.
GREENWICH.— Slack tourmaline.
HADDAM. — Chrysoberyl! beryl! epidote! tourmaline! feldspar, gar-
net! iolite! oligoclase, chlorophyllite ! automolite, magnetite^ adularia,
apatite, columbite! (hermannolite), zircon (calyptolitc), mica, pyrite,
marcasite, molybdenite,^ allanite, bismuth ochre, bismutite.
HADLYME. — Chabazite and stilbite in gneiss with epidote and gar-
net.
HARTFORD. — Datolite (Rocky Hill quarry).
KENT.— Limonite, pyrolusite.
LITCHFIELD. — Cyanite with corundum, apatite, and andalusite, me-
naccanite (washingtonite), chalcopyrite, diaspore, niccoliferous pyrrho-
tite, margarodite.
LYME. — Garnet, sunstone.
MIDDLEFIELD FALLS. — Datolite, chlorite, etc., in amygdaloid.
MIDDLETOWN. — Mica, lepidolite with green and red tourmaline,
albite, feldspar, columbite ! prehnite, garnet (sometimes octahedral),
beryl, topaz, uranite, apatite, pitchblende ; at lead mine, galenite, chal-
copyrite, blende, quartz, calcite, fluorite, pyrite sometimes capillary.
MILFORD. — Sahlite, pyroxene, asbestus, zoisitc, verd-antique, marble,
pyrite.
NEW BRITAIN. — Agate, diabantile, barite, datolite, prehnite, calcite,
dolomite.
NEW HAVEN.— Serpentine, sahlite, stilbite, prehnite, chabazite,
laumontite, gmelinite, apophyllite, topazolite.
NEWTOWN. — Cyanite, diaspore, rutile, damourite, cinnabar.
NORWICH. — Sillimanite, monazite ! iolite, corundum, feldspar.
OXFORD (near Humphreysville). — Cyanite, chalcopyrite.
PORTLAND. — Orthoclase, albite, muacovite, biotite, beryl, tourmaline,
columbite, apatite.
PLYMOUTH. —Galenite, heulandite, fluorite, chlorypliyllite ! garnet.
REDDING (near the line of Danbury). — Pyroxene, garnet. Near
Branchville R. R. depot : Albite, microcline, hebronite, spodumene !
cymatolite, damourite, eosphorite. triploidite, reddingite, dickinsonite,
lithiophilite, rhodocltrosite, fairlieldite, apatite, microlite, columuife,
garnet, pyrite, tourmaline, staurolite, uranmite, torbernite, autunite,
vivianite, triphylite.
ROARING BROOK (Cheshire).— Datolite f calcite, prehnite, saponite.
ROXBURY. —Siderite, blende, pyrite ! ! galenite, quartz, chalcopyrite,
arsenopyrite, limonite.
SALISBURY. — Limonite, pyrolusite, triplite, turgite.
SAYBROOK.— Molybdenite, stilbite, plumbago.
SEYMOUR. — Native bismuth, arsenopyrite, pyrite.
SIMSBURY. — Copper glance, green malachite.
SOUTHBURY. — Rose quartz, laumontite, prehnite, calcite, barite.
SOUTHINGTON. — Barite, datolite, asteriated quartz crystals. •
STAFFORD. — Massive pyrites, alum, copperas.
STONINGTON. — Stilbite and chabazite on gneiss.
TARIFF VILLE. — Datolite.
TOLLAND.— Staurolite, massive pyrites.
TRUMBULL and MONROE. — Chlorophane, topaz, beryl, diaspore, pyr-
Jrhotite, pyrite, niccolite, scheelite, wolframite (pseudomorph of scheel-
ite), rutile, native bismuth, tungstic acid, siderite, arsenopyrite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 343
argentiferous galenite, blende, scapolite, tourmaline, garnet, albitc,
augite, graphic tellurium {?), margarodite.
WASHINGTON. — Tripolite, menaccanite! (washingtonite of Shepard),
rhodochrosite, natrolite. andalusite (New Preston), cyanite.
WATERTOWN, near the Naugatuck. — White sahlite, monazite.
WEST FARMS. — Asbestus.
WILLIMANTIC. — Topaz, monazite, ripidolite.
WINCHESTER and WILTON. — Asbestus, garnet.
NEW YORK.
ALBANY CO.— BETHLEHEM.— Calcite, stalactite, stalagmite, calca-
reous sinter, snowy gypsum.
COEYMAN'S LANDING. —Gypsum, epsoni salt, quartz crystals at
Crystal Hill, three miles south of Albany.
GUILDERLAND. — Petroleum, anthracite, and calcite, on the banks
of Norman's Kill, two miles south of Albany.
WATER VLIET. — Quartz crystals, yellow drusy quartz.
ALLEGHANY CO.— CUBA.— Calcareous tufa, petroleum, 3£ miles
from the village.
CATTARAUGUS CO.— FREEDOM.— Petroleum.
CAYUGA CO.— AUBURN.— Celestite, calcite, nuor spar, epsomite.
SPRINGPORT. — At Thompson's plaster beds, sulphur! selenite.
SPRING VILLE. — Nitrogen springs.
UNION SPRINGS. — Selenite, gypsum.
CHATAUQUE CO.— FREDONIA. — Petroleum, carburetted hydrogen.
LAON A. — Petroleum.
CLINTON CO. —ARNOLD IRON TATSK.— Magnetite, epidote, molybde-
nite.
FINCH ORE BED.— Calcite, green and purple fluor.
COLUMBIA CO.— AUSTERLITZ. - -Earthy manganese, wnlfenite,
chalcocite ; Livingston lead mine, galenite.
CHATHAM. — Quartz, pyrite in cubic crystals in slate (Hillsdale).
CANAAN. — Chalcocite, chalcopyrite.
HUDSON.— Epidote, selenite!
NEW LEBANON. — Nitrogen springs, graphite, anthracite ; at the
Ancram lead mine, galenite, barite, blende, wulfenite (rare), chalcopy-
rite, calcareous tufa; near the city of Hudson, epsom salt, brown
spar, wad.
DUTCHESS CO.— AMENIA.— Dolomite, limonite, turgite.
BEEKM AN. — Dolomite.
DOVER. — Dolomite, tremolite, garnet (Foss ore bed), staurolite,
limonite.
FISHKILL. — Dolomite ; near Peck vi lie, talc, asbestus, graphite, horn-
Uende, augite, actinolite, hydrous anthophyllite, limonite.
NORTH EAST. — Chalcocite, chalcopyrite, galenite, blende.
RHINEBECK.— Calcite, green feldspar, epidote, tourmaline.
UNION VALE. — At the Clove mine, gibbsite, limonite.
ESSEX CO.— ALEXANDRIA.— Kirby's graphite mine, graphite, py-
roxene, scapolite, sphene.
CROWN POINT. — Apatite (eupyrchroite of Emmons), brown tourma-
line ! in the apatite, chlorite, quartz crystals, pink and blue calcite,
344 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
pyrite ; a short distance south of J. C. Hammond's house, garnet,
scapolite, chalcopyrite, aventurine feldspar, zircon, magnetic iron
(Peru), epidote, mica.
KEENE. — Scapolite.
LE>VIS. — labular spar, colophonite, garnet, labradorite, hornblende,
actinolite ; ten miles south of the village of Keeseville, arsenopyrite.
LONG POND. — Apatite, garnet, pyroxene, idocrase, coccolite! I scapo-
lite, magnetite, Hue calcite.
MclNTYRE. — Labradorite, garnet, magnetite.
MORIAH, at Sandford Ore Bed. — Magnetite, apatite, allanite ! lan-
thanite, actinolite, and feldspar ; at Fisher Ore Bed, magnetite, feld-
spar, quartz ; at Hail Ore Bed, or " New Ore Bed," magnetite, zircons;
on Mill brook, calcite, pyroxene, hornblende, albite ; in the town of
Moriah, magnetite, black mica ; Barton Hill Ore Bed, albite.
NEWCOMB. — Labradorite, feldspar, magnetite, hypersthene.
PORT HENRY. — Brown tourmaline, mica, rose quartz, serpentine,
green and black pyroxene, hornblende, cryst. pyrite, graphite, wollas-
tonite, pyrrhotite, adularia ; phlogopite! at Cheever Ore Bed, with
magnetite and serpentine.
ROGER'S ROCK. — Graphite, wollastonite, garnet, collophonite, feld-
spar, adularia, pyroxene, sphene, coccolite.
SCHROON. — Calcite,, pyroxene, chondrodite.
TicoNDEROGA. — Graphite ! pyroxene, sahlite, sphene, black tour-
maline, cacoxene ? (Mt. Defiance).
WESTPORT. — Labradorite, prehnite, magnetite.
WILLSBORO'. — Wollastonite, colophonite, garnet, green coccolite, horn-
blende.
ERIE CO.— ELLICOTT'S MILLS. — Calcareous tufas.
. FRANKLIN CO.— CHATEAUGAY. — Nitrogen springs, calcareous
tufas.
M ALONE. — Massive pyrite, magnetite.
GENESEE CO.— Acid springs containing sulphuric acid.
GREENE CO.— CATSKILL.— (Mctte.
DIAMOND HILL. — Quartz crystals.
HAMILTON CO.— LONG LAKE.— Blue calcite.
HERKIMER CO.— FAIRFIELD.— Quartz crystals, fetid barite.
LITTLE FALLS. — Quartz crystals I barite, calcite, anthracite, pearl
spar, smoky quartz; one mile south of Little Falls, calcite, brown
spar, feldspar.
MIDDLEVILLE. — Quartz crystals ! calcite, brown and pearl spar, an-
thracite.
NEWPORT. — Quartz crystals.
SALISBURY. — Quartz crystals! blende, galenite, pyrite, chalcopyrite.
STARK. — Fibrous celestite, gypsum.
JEFFERSON CO.— ADAMS.— Fluor, calc tufa, barite.
ALEXANDRIA. — On the S. E. bank of Muscolonge Lake, fluorite
(exhausted), phlogopite, chalcopyrite, apatite ; on High Island, in the St.
Lawrence River, feldspar, tourmaline, hornblende, orthoclase, celestite.
ANTWERP.— Sterling iron mine, hematite, chalcodite, siderite, mil-
lerite, red hematite, crystallized quartz, yellow aragonite, niccoliferous
pyrite, quartz crystals, pyrite ; at Oxbow, calcite ! porous coralloidal
heavy spar ; near Viooman's lake, calcite ! vesuvianite, phlogopite !
pyroxene, sphene, fluorite, pyrite, chalcopyrite ; also feldspar, bog-iron
CATALOGUE OF AMERICAN LOCALITIES OP MINERALS. 345
ore, scapolite (farm of Eggleson), serpentine, tourmaline (yellow,
rare).
BROWNSVILLE. — Celestite in slender crystals, calcite (four miles
from Watertown).
NATURAL BRIDGE. — Oieseckite! steatite pseudomorphous after py-
roxene, apatite.
NEW CONNECTICUT. — Sphene, brown phlogopite.
OMAR. — Beryl, feldspar, hematite.
PHILADELPHIA. — Garnets on Indian River, in the village.
PAMELIA. — Agaric mineral, calc tufa.
PIERREPONT. — Tourmaline, sphene, scapolite, hornblende.
PILLAR POINT.— Massive barite (exhausted).
THERESA. — Fluorite, calcite, hematite, hornblende, quartz crystal,
serpentine (associated with hematite), celestite, strontianite.
WATERTOWN.— Tremolite, agaric mineral, calc tufa, celestite.
WILNA. — One mile north of Natural Bridge, calcite.
LEWIS CO. — DIANA (localities mostly near junction of crystalline
and sedimentary rocks, and within two miles of Natural Bridge). —
Scapolite ! wollastonite, green coccolite, feldspar, tremolite, pyroxene !
sphene! ! mica, quartz crystals, drusy quartz, cryst. pyrite, pyrrhotite,
blue calcite, serpentine, rensselaerite, zircon, graphite, chlorite, hema-
tite, bog-iron ore, iron sand, apatite.
GREIG. — Magnetite, pyrite.
LOWVILLE. — Calcite, fluorite, pyrite, galenite, blende, calc tufa.
MARTINSBURGH. — Wad, galenite, etc., but mine not now opened,
calcite.
MONROE CO. — ROCHESTER. — Pearl spar, calcite, snowy gypsum,
fluor, celestite, galenite, blende, barite, hornstone.
MONTGOMERY CO.— PALATINE.— Quartz crystals, drusy quartz,
anthracite, hornstone, agate, garnet.
ROOT. — Drusy quartz, blende, barite, stalactite, stalagmite, galenite,
pyrite.
NEW YORK CO.— CORLEAR'S HOOK.— Apatite, brown and yellow
feldspar, sphene.
HARLEM. — Epidote, apophyllite, stilbite, tourmaline, vivianite,
lamellar feldspar, mica.
KINGSBRIDGE. — T)'emolite,pyroxene, mica, tourmaline, pyrite, rutile,
dolomite.
NEW YORK. — Serpentine, amianthus, actinolite, pyroxene, hydrous
anthophyllite, garnet, staurolite, molybdenite, graphite, chlorite,
jasper, necronite, feldspar. In the excavations for the 4th Avenue
tunnel, 1875, harmotome, stilbite, chabazite, heulandite, etc.
NIAGARA CO. — LEWISTON. — Epsomite.
LOCKPORT. — Celestite, calcite, selenite, anhydrite, fluorite, dolomite,
blende.
NIAGARA FALLS. — Calcite, fluorite, blende, dolomite.
ONEIDA CO.— BOONVILLE.— Calcite, wollastonite, coccolite.
CLINTON. — Blende, lenticular argillaceous iron ore in rocks of the
Clinton group, strontianite, celestite, the former covering the latter.
ONONDAGA CO.— CAMILLUS.— Selenite and fibrous gypsum.
COLD SPRING.— Axinite.
MANLIUS. — Gypsum and fluor.
SYRACUSE.— Serpentine, celestite, selenite, barite.
SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
ORANGE CO.— CORNWALL.— Zircon, chondrodite, hornblende, spinel,
massive feldspar, fibrous epidote, hudsonite, menaccanite, serpentine,
coccolite.
DEER PARK. — Cryst. pyrite, galenite.
MONROE. — Mica ! sphene ! garnet, colophonite, epidote, chondrodite,
aUanite, bucholzite, brown spar, spinel, hornblende, talc, menaccanite,
pyrrhotite, pyrite, chromite, graphite, rastolyte. moronolite.
At WILKS and O'NEILL Mine in Monroe. — Aragonite, magnetite,
dimagnetite (pseud.?), jenkinsite, asbestus, serpentine, mica, hortono-
lite.
At Two PONDS in Monroe. — Pyroxene! chondrodite, hornblende,
scapolite! zircon, sphene, apatite.
At GREENWOOD FURNACE in Monroe. — Chondrodite, pyroxene!
mica, hornblende, spinel, scapolite, biotite! menaccanite.
At FOREST OF DEAN. — Pyroxene, spinel, zircon, scapolite, horn-
blende.
TOWN OP WARWICK, WARWICK VILLAGE. — Spinel! zircon, serpen-
tine! brown spar, pyroxene! hornblende! pseudomorphous steatite,
feldspar! (Rock Hill), menaccanite, clintonite, tourmaline (R. H.),
rutile, sphene, molybdenite, arsenopyrite, marcasite, pyrite, yellow
iron sinter, quartz, jasper, mica, coccolite.
AMITY. — Spinel! garnet, scapolite, hornblende, vesuvianite, epidote!
clintonite ! magnetite, tourmaline, warwickite, apatite, chondrodite,
talc! pyroxene! rutile, menaccanite, zircon, corundum, feldspar,
sphene, calcite, serpentine, schiller spar (?), silvery mica.
EDENVILLE. — Apatite, chondrodite ! hair -brown hornblende ! tremo-
lite, spinel, tourmaline, warwickite, pyroxene, sphene, mica, feldspar,
arsenopyrite, orpiment, rutile, menaccanite, scorodite, chalcopyrita,
leucopyrite (or lollingite), allanite.
WEST POINT. — Feldspar, mica, scapolite, sphene, hornblende, allanite.
PUTNAM CO.— BREWSTER, Tilly Foster Iron Mine.— Chondrodite!
(also humite and clino-humite) crystals very rare, magnetite, dolomite,
serpentine, pseudomorphs, brucite, enstatite, ripidolite, biotite, actino-
lite, apatite, pyrrhotite, fluorite, albite, epidote, sphene.
ANTHONY'S NOSE, at top, pyrite, pyrrhotite, pyroxene, hornblende,
magnetite.
CARMEL (Brown's quarry). — Anthophyllite, schiller spar (?), orpi-
ment, arsenopyrite, epidote.
COLD SPRING. — Chabazite, mica, sphene, epidote.
PATTERSON. — White pyroxene! calcite, asbestus, tremolite, dolomite,
massive pyrite.
PHILLIPSTOWN. — Tremolite, amianthus, serpentine, sphene, diopside,
C'.n coccolite, hornblende, scapolite, stilbite, mica, laumontite, gur-
te, calcite, magnetite, chromite.
PHILLIPS Ore Bed. — Hyalite, actinolite, massive pyrite.
RENSSELAER CO.— Hoosic.— Nitrogen springs.
LANSINGBURGH. — Epsomite, quartz crystals, pyrite.
TROY. — Quartz crystals, pyrite, selenite.
RICHMOND CO.— ROSSVILLE. —Lignite, cryst. pyrite.
QUARANTINE. — Asbestus, amianthus, aragonite, dolomite, gurhofite
brucite, serpentine, talc, magnesite.
ROCKLAND CO.— CALDWELL.— Calcite.
GRASSY POINT.— Serpentine, actinolite.
CATALOGUE OP AMERICAN LOCALITIES OF MINERALS. 347
HAVEB STRAW. — Hornblende, barite.
LADENTOWN. — Zircon, malachite, cuprite.
PIERMONT. — Datolite, stilbite, apophyllite, stellite, prehnite, tliom-
sonite, calcite, chabazite.
ST. LAWRENCE CO.— CANTON.— Massive pyrite, calcite, brown
tourmaline, sphene, serpentine, talc, rensselaerite , pyroxene, hematite,
chalcopyrite.
DE KALE.— Hornblende, barite, fluorite, trcmolite, tourmaline, blende,
graphite, pyroxene, quartz (spongy), serpentine.
EDWARDS, — Brown and silvery mica ! scapolite, apatite, quartz crys-
tals, actinolite, tremolite! hematite, serpentine, magnetite.
FINE. — Black mica, hornblende.
FOWLER. — Barite, quartz crystals ! hematite, blende, galenite, tremo-
lite, chalcedony, bog ore, satin spar (assoc. with serpentine), pyrite,
chalcopyrite, actinolite, rensselaerite (near Somerville).
GOUVERNEUR. — Calcite ! serpentine! Jwrriblende! scapolite! ortho-
clase, tourmaline ! idocrase (one mile south of G.), pyroxene, malaco-
lite, apatite, rensselaerite, serpentine, sphene, fluorite, barite (farm of
Judge Dodge \ black mica, phlogopite, tremolite! asbestus, hematite,
graphite, vesuvianite (near Somerville in serpentine), spinel, houghite,
scapolite, phlogopite, dolomite ; three-quarters of a mile west of Som-
erville, chondrodite, spinel ; two miles north of Somerville, apatite,
pyrite, brown tourmaline / !
HAMMOND. — Apatite! zircon! (farm of Mr. Hardy), orthoclase (loxo
case\ pargasite, barite. pyrite, purple fluorite, dolomite.
HERMON. — Quartz crystals, hematite, siderite, pargasite, pyroxene,
serpentine, tourmaline, bog-iron ore.
MACOMB. — Blende, mica, galenite (on land of James Averill),
ephene.
MINERAL POINT, Morristown. — Fluorite, blende, galenite, phlogo-
pite (Pope's Mills), barite.
OGDENSBURGH. — Labradorite .
PITCAIRN.— Satin spar, associated with serpentine.
POTSDAM. — Hornblende! ; eight miles from Potsdam, on road to
Pierrepont, feldspar, tourmaline, black mica, hornblende.
ROSSIE (Iron Mines). — Barite, hematite, coralloidal aragonite in
mines near Somerville, limonite, quartz (sometimes stalactitic at
Parish Iron Mine\ pyrite, pearl spar.
ROSSIE Lead Mine. — Calcite! galenite! pyrite, celestite, chalcopyrite,
hematite, cerussite, anglesite, octahedral fluor, black phlogopite.
Elsewhere in ROSSIE. — Calcite, barite, quartz crystals, chondrodite
(near Yellow Lake), feldspar! pargasite! apatite, pyroxene, horn-
blende, sphene, zircon, mica, fluorite, serpentine, automolite, pearl
spar, graphite.
RUSSEL. — Pargasite, specular iron, quartz (dodec.), calcite, serpen-
tine, rensselaerite, magnetite.
SARATOGA CO.— GREENFIELD.— Chrysoberyl! garnet! tourma-
line ! 'mica, feldspar, apatite, graphite, aragonite (in iron mines).
SCHOHARIE CO.— BALL'S CAVE, and others.— Calcite, stalactites.
CARLISLE. — Fibrous barite, cryst. and jibrous calcite.
MIDDLEBURY. — Asphaltic coal, calcite.
SHARON. — Calcareous tufa.
SCHOHARIE. — Fibrous celestite, strontianite ! cryst. pyrite!
348 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
SENECA CO.— CANOGA.— Nitrogen springs.
SULLIVAN CO.— WURTZBORO'.— Galenite, Uende, pyrite, chalco>
pyrite.
TOMPKINS CO.— ITHACA. -Calcareous tufa.
ULSTER CO. — ELLENVILLE. — Galenite, blende, chalcopyrite /
quartz, brookite.
M ARBLETOWN. — Pyrite.
WARREN CO. — CALDWELL. — Massive feldspar.
CHESTER. — Pyrite, tourmaline, rutile, chalcopyrite.
DIAMOND ISLE (Lake George). — Calcite, quartz crystals.
GLENN'S FALLS. — Rhomb spar.
JOHNSBUHGH. — Fluorite! zircon! graphite, serpentine, pyrite.
WASHINGTON CO.— FORT ANN.— Graphite, serpentine.
GRANVILLE. — Lamellar pyroxene, massive feldspar, epidote.
WAYNE CO.— WOLCOTT.— Barite.
WESTCHESTER CO.— ANTHONY'S NOSE.— Apatite, pyrite, calcite!
in very large tabular crystals, grouped, and sometimes incrusted with
drusy quartz.
DAVENPORT'S NECK. — Serpentine, garnet, sphene.
EASTCHESTER. — Blende, pyrite, chalcopyrite, dolomite.
HASTINGS. — Tremolite, white pyroxene.
NEW ROCHELLE. — Serpentine, brucite, quartz, mica, tremolite, gar-
net, magnesite.
: PEEKSKILL. — Mica, feldspar, hornblende, stilbite, sphene ; three
miles south, emery.
RYE. — Serpentine, chlorite, black tourmaline, tremolite.
SING SING. — Pyroxene, tremolite, pyrite, beryl, azurite, green mala-
chite, cerussite, pyromorphite, anglesite, vauquelinite, galenite, native
silver, chalcopyrite.
WEST FARMS. — Apatite, tremolite, garnet, stilbite, heulandite, cha-
bazite, epidote, sphene.
YONKEUS. — Tremolite, apatite, calcite, analcite, pyrite, tourmaline.
YORKTOWN. — Fibrolite, monazite, magnetite.
WYOMING CO.— WYOMING.— Rock salt.
NEW JERSEY.
ANDOVER IRON MINE (Sussex Co.)— Will emite, brown garnet.
ALLENTOWN (Monmouth Co.) — Vivianite, dufrenite.
BELLVILLE. — Copper mines.
. BERGEN.— Calcite! datolite! pectolite ! analcite, apophyllite! gme~
Unite, prehnite, sphene, stilbite, natrolite, heulandite, laumontite, cha-
bazite, pyrite, pseudomorphous steatite imitative of apophyllite,
diabantite.
BRUNSWICK. — Copper mines : native copper, malachite, mountain
leather.
BRYAM. — Chondrodite, spinel, at Roseville, epidote.
CANTWELL'S BRIDGE (Newcastle Co.), three miles west. — Vivian-
ite.
DANVILLE (Jemmy Jump Ridge). — Graphite, chondrodite, augite,
mica.
FLEMINGTON, — Copper mines.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 349
FRANKFORT. — Serpentine.
FRANKLIN and STERLING (Sussex Co.). — Spinel ! garnet i rhodonite !
willemite ! franklinite ! zincite ! dysluite ! hornblende, tremolitK, chon-
drodite, white scapolitc, black tourmaline, epidote, mi^a, actinohte,
augite, sahlite, cocblite. asbestus, jcffcrsontte (augite). calamine, graph-
ite, fluorite, beryl, galenite, serpentine, honey-colored sphene, quart/,
chalcedony, amethyst, zircon, molybdenite, vivianite, tephroite, rhodo-
chrosite, aragonite, sussexite, chalcophanite, rcepperite, calcozincito,
vanuxemite, gahnite, hetaerolitc. Also algerite in gran, limestone.
FRANKLIN and WARWICK MTS. — Pyrite.
GREENBROOK. — Copper mines.
GRIGGSTOWN. — Copper mines.
HAMBURGH. — One mile north, spinel ! tourmaline, phlogopite, horn-
blende, limonite, hematite.
HOBOKEN. — Serpentine (marmolite), brucite, nemalite (or fibrous bru-
cite), aragonite, dolomite.
HURDSTOWN. — Apatite, pyrrhotite, magnetite.
IMLAYSTOWN. — Vivianite.
LOCKWOOD. — Graphite, chondrodite, talc, augite, quartz, green spi-
nel.
MONTVILLE (Morris Co.) — Serpentine, chrysotile.
MULLICA HILL (Gloucester Co.) — Vivianite lining belemnites and
other fossils.
I NEWTON. — Spinel, blue, pink, and white corundum, mica, vesuvian-
ite, hornblende, tourmaline, scapolite, rutile, pyrite, talc, calcite, barite,
pseudomorphous steatite.
PATERSON. — Datolite.
VERNON. — Serpentine, spinel, hydrotalcite.
PENNSYLVANIA.*
ADAMS CO.— GETTYSBURG. — Epidote, fibrous and massive.
BERKS Co. — MORGANTOWN. — At Jones's mines, one mile east of
Morgantown, malachite, native copper, cJirysocolla, magnetite, allo-
phane, pyrite, chalcopyrite, aragonite, apatite, talc, venerite ; two
miles N. E. from Jones's mine, graphite, sphene ; at Steele's mine,
one mile N. W. from St. Mary's, Chester Co., magnetite, micaceous
iron, coccolite, brown garnet.
READING. — Smoky quartz crystals, zircon, stilbite, iron ore ; near
Pricetown, zircon, allanite, epidote ; at Eckhardt's Furnace, allanite
with zircon ; at Zion's Church, molybdenite ; near Kutztown, in the
Crystal Cave, stalactites ; at Fritz Island, apophyllite, thomsonite, cha-
bazite, calcite, azurite, malachite, magnetite, chalcopyrite, stibnite,
prochlorite, precious serpentine.
BUCKS CO.— BUCKINGHAM TOWNSHIP. — Crystallized quartz ; near
New Hope, vesuvianite, epidote, barite.
SOUTHAMPTON. — Near the village of Feasterville, in the quarry of
George Van Arsdale, graphite, pyroxene, sahlite, coccolite, sphene,
green mica, calcite, wollastonite, glassy feldspar sometimes opalescent,
phlogopite, blue quartz, garnet, zircon, pyrite, moroxite, scapolite.
* See also the Report on the Mineralogy of Pennsylvania, by Dr. F. A. Genth,
1875,
850 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
NEW BRITAIN. — Dolomite, galenite, blende, malachite.
CARBON CO. — SUMMIT HILL, in coal mines. — Kaolinite.
CHESTER CO. — AVONDALE.— Asbestus, tremolite, garnet, opal.
BIRMINGHAM TOWNSHIP. — Amethyst, smoky quartz, serpentine,
beryl ; in Ab'm Darlington's lime quarry, calcite.
EAST BRADFORD. — Near Buffington's bridge, on the Brandy wine,
green, blue, and gray cyanite, the gray cyanite found loose in the
soil, in crystals ; on the farms of Dr. Elwyn, Mrs. Foulke, Wm. Gib-
bons, and Saml. Entrikin, amethyst. At Strode's mill, asbestus, mag-
nesite, anthophyllite, epidote, aquacrepitite, oligoclase, drusy quartz,
collyrite ? on O.-;borne's Hill, wad, manganesian garnet (massive), sphene
schorl ; at Caleb Cope's lime quarry, fetid dolomite, necronite, garnets,
blue cyanite, yellow actinolite in talc ; near the Black Horse Inn, indu-
rated talc, rutile ; on Amos Davis's farm, orthite! massive, from a grain
to lumps of one pound weight ; near the paper-mill on the Brandy-
wine, zircon, associated with titaniferous iron in blue quartz.
WEST BRADFORD. — Near the village of Marshalton, green cyanite,
rutile, scapolite, pyrite, staurolite ; at the Chester County Poor-house
limestone quarry, chesterlite ! in crystals implanted on dolomite, ru-
tile ! in brilliant acicular crystals, which are finely terminated, calcite
in scalenohedrons, zoisite, damourite ? in radiated groups of crystals
on dolomite, quartz crystals ; on Smith & McMullin's farm, epidote.
CHARLESTOWN. — Pyromorphite, cerussite, galenite, quartz.
COVENTRY. — Allanite, near Pughtown.
SOUTH COVENTRY. — In Chrisman's limestone quarry, near Coventry
village, augite, sphene, graphite, zircon in iron ore (about half a mile
from the village).
EAST FALLOWFIELD. — Soapstone.
EAST QOSHEN. — Serpentine, asbestus, magnetite (lodestone), gar-
net.
ELK. — Menaccanite with muscovite, chromite ; at Lewisville, black
tourmaline.
WEST QOSHEN. — On the Barrens, one mile north of West Chester,
amianthus, serpentine, cellular quartz, jasper, chalcedony, drusy
quartz, chlorite, marmolite, indurated talc, magnesite in radiated crys-
tals on serpentine, hematite, asbestus; near R. Taylor's mill, chromite
in octahedral crystals, deweylite, radiated magnesite, aragonite, stauro-
lite, garnet, asbestus, epidote ; zoisite on hornblende at West Chester
water- works (not accessible at present).
NEW GARDEN. — At Nivin's limestone quarry, broicn tourmaline, ne-
cronite, scapolite, apatite, brown and green mica, rutile, aragonite,
fibrolite, kaolinite, tremolite.
KENNETT. — Actinolite, brown tourmaline, brown mica, epidote, tre-
molite, scapolite, aragonite ; on Wm. Cloud's farm, sunstone! ! cha-
bazite, sphene. At Pearce's old mill, zoisite, epidote, sunstone ; sun-
stone occurs in good specimens at various places in the range of horn-
blende rocks running through this township fromN. E. toS. W.
LOWER OXFORD.— Garnets, pyrite in cubic crystals.
LONDON GROVE. — Rutile, jasper, chalcedony (botryoidal), large and
rough quartz crystals, epidote ; on Wm. Jackson's farm, ydlow and
Hack tourmaline, tremolite, rutile, green mica, apatite ; at Pusey's
quarry, rutile, tremolite.
EAST MARLBOROUGH. — On the farm of Bailey & Brother, one mile
CATALOGUE OP AMERICAN LOCALITIES OP MINERALS. 351
south of Unionville, bright yellow and nearly white tourmaline, ches-
terlite, albite, pyrite ; near Marlborough meeting-house, epidote, ser-
pentine, acicular black tourmaline in white quartz ; zircon in small
perfect crystals loose in the soil at Pusey's sawmill, two miles S. W.
of Unionville.
WEST MARLBORO UGH. — Near Logan's quarry, staurolite, cyanite,
yellow tourmaline, rutile, garnets ; near Doe Run village, hematite,
scapolite, tremolite ; in R. Baily's limestone quarry, two and a half
miles S. VV. of Unionville, fibrous tremolite, cyanite, scapolite.
NEWLIN. — On the serpentine barrens, one and a half mile N. E. of
Unionville, corundum ! massive and crystallized, also in crystals in
albite, often in loose crystals covered with a thin coating of steatite,
spinel (black), talc, picrolite, brucite, green tourmaline, with flat pyram-
idal terminations in albite, unionite, (rare), enphyllit?, mica in hexagonal
crystals, feldspar, beryl! in hexagonal crystals one of which weighs
51 Ibs., pyrite in cubic crystals, chromic iron, drusy quartz, green
quartz, actinolite, emerylits, chloritoid, diallage, oliyoclase ; on John-
son Patterson's farm, massive corundum, titaniferous iron, clinocMore,
emerylite, sometimes colored green by chrome, albite, orthoclase, hal-
loysite, margarite, garnets, beryl; on J. Lesley's farm, corundum,
crystallized and in massive lumps one of which weighed 5,200 Ibs.,
diaspore ! ! emerylite! euphyllite, crystallized! green tourmaline, in
transparent crystals in the euphyllite, orthoclase ; two miles N. of
Unionville, magnetite in octahedral crystals ; one mile E. of Union-
ville, hematite; in Edwards's old limestone quarry, purple fluorite,
rutile.
EAST NOTTINGHAM.— Asbestus, chromite in crystals, hallite, beryl.
WEST NOTTINGHAM. — At Scott's chrome mine, chromite, foliated
talc, marmolite, serpentine, chalcedony, rhodochrome ; near Moro Phil-
lips's chrome mine, asbestus ; at the magnesia quarry, deweylite, mar-
molite, magnesite, leelite, serpentine, chromite ; near Fremont P. O.,
corundum.
WEST PIKELAND. — In the iron mines near Chester Springs, gibbsite,
zircon, turgite, hematite (stalactitical and in geodes), gothite.
PENN. — Garnets, agalmatolite.
PENNSBURY. — On John Craig's farm, brown garnets, mica ; on J.
Dil worth's farm, near Fairville, muscovite ! in the village of Fair-
ville, sunstone ; near Brinton's Ford, on the Brandywine, chondrodite,
yphene, diopside, augite, cocoolite ; at Mendenhall's old limestone
quarry, fetid quartz, sunstone ; at Swain's quarry, orthoclase.
POCOPSON. — On the farms of John Entrikin and Jos. B. Darlington,
amethyst.
SADSBURY. — Rutile ! f splendid geniculated crystals are found loose
in the soil for seven miles along the valley, and particularly near the
village of Parkesburg, where they sometimes occur weighing on»
pound, doubly geniculated and of a deep red color ; near Sadsbury
village, amethyst, tourmaline, epidote, milk quartz.
SCHUYLKILL. — In the railroad tunnel at PHCENIXVILLE, dolomite!
sometimes coated with pyrite, quartz crystals, yellow blende, brookite,
calcite in hexagonal crystals enclosing pyrite; at the WHEATLEY,
BROOKDALE, and CHESTER COUNTY LEAD MINES, one and a half
mile S. of Phrenixville, pyromorphite ! cerussite ! galenite, anglesite f !
quartz crystals, chalcopyrite, barite, fluorite (white), stolzite, wulfenite }
352 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
calamine, vanadinite, blende ! mimetite / descloizite, gothite, chryso-
colla, native copper, malachite, azurite, limonite, calcite, sulphur, py-
rite, melaconite, pseudomalachite, gersdorffite, chalcocite ? covellite.
THORNBURY. — On Jos. H. Brinton's farm, muscovite containing ajcic-
ular crystals of tourmaline, rutile, titaniferous iron.
TREDYFFRIN. — Pyrite in cubic crystals loose in the soil.
UWCHLAN. — Massive bine quartz, graphite.
WARREN. — Melanite, feldspar.
WEST GOSHEN (one mile from West Chester). — Chromite.
WILLISTOWN. — Magnetite, chromite, actinolite, asbestus.
WEST TOWN. — On the serpentine rocks, 3 miles' S. of West Ches-
ter, dinochlore ! jefferisite ! mica, asbestus, actinolite, magnesite, talc,
titaniferous iron, magnetite and massive tourmaline.
EAST WHITELAND. — Pyrite, in cubic crystals, quartz crystals.
WEST WHITELAND. — At Gen. Trimble's iron mine (southeast), stal-
actitic hematite ! wavellite I ! in radiated stalactites, gibbsite, coeruleo-
lactile.
WARWICK. — At the Elizabeth mine and Keim's old iron mine
adjoining, one mile N. of Knauertown, aplome garnet ! in brilliant
dodecahedrons, flosferri, pyroxene, micaceous hematite, pyrite in bright
octahedral crystals in calcite, chrysocolla, chalcopyrite massive and in
single tetrahedral crystals, magnetite, fuscicular hornblende ! bornite,
malachite, brown garnet, calcite, byssolite ! serpentine ; near the village
of St. Mary's, magnetite in dodecahedral crystals, melanite, garnet ',
actinolite in small radiated nodules ; at the Hopewell iron mine, one
mile IS. W. of St. Mary's, magnetite in octahedral crystals.
COLUMBIA CO. — At Webb's mine, yellow blende in calcite ; near
Bloomburg, cryst. magnetite.
DAUPHIN CO. — NEAR HUMMELSTOWN. —Green garnets, cryst.
amoky quartz, feldspar, micaceous hematite, stilbite, chrysocolla.
DELAWARE CO. — ASTON TOWNSHIP. — Amethyst, corundum, eme-
rylite, staurolite, fibrolite, black tourmaline, margarite, sunstone, asbes-
tus, anthophyllite, steatite ; near Tyson'o mill, garnet, staurolite ; at
Peter's milldam in the creek, pyrope garnet.
BIRMINGHAM. — Fibrolite, kaolin (abundant), crystals of rutile, ame-
thyst ; at Bullock's old quarry, zircon, bucholzite, nacrite, yellow crys-
tallized quartz, feldspar.
BLUE HILL. — Green quartz crystals, spinel.
CHESTER. — Amethyst, black tourmaline, beryl, crystals of feldspar,
garnet, cryst. pyrite, molybdenite, molybdite, chalcopyrite, kaolin, ura-
ninite, muscovite, orthoclase, bismutite.
CHICHESTER. — Near Trainer's milldam, beryl, tourmaline, crystals
of feldspar, kaolin ; on Wm. Eyre's farm, tourmaline.
CONCORD. — Mica, feldspar, kaolin, drusy quartz, meerschaum, stel-
lated tremolite, anthophyllite, fibrolite, acicular crystals of rutile, py-
rope in quartz, amethyst, actinolite, manganesian garnet, beryl ; in
Green's creek, pyrope garnet.
DARBY. — Blue and gray cyanite, garnet, staurolite, zoisite, quartz,
beryl, chlorite, mica, limonite.
EDGEMONT. — Amethyst, oxide of manganese, crystals of feldspar;
one mile east of Edgemont Hall, rutile in quartz.
GREEN'S CREEK. — Garnet (so-called pyrope).
- HAVERFORD. — Staurolite with garnet.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 353
MARPLE. — Tourmaline, andalusite, amethyst, actinolite, antJiophyl*
lite, talc, radiated actinolite in talc, chromite, drusy quartz, beryl,
cryst. pyrite, menaccanite in quartz, chlorite.
MIDDLETOWN. — Amethyst, beryl, black mica, mica with reticulated
magnetite between the plates, manganesian garnets! large trapezo
hedral crystals, some 3 in. in diameter, indurated talc, hexagonal
crystals of rutile, crystals of mica, green quartz ! anthophyllite, radi-
ated tourmaline, staurolite, titanic iron, fibrolite, serpentine ; at Len-
ni, chlorite, green and bronze vermiculite! green feldspar ; at Mineral
Hill, fine crystals of corundum, one of which weighs If lb., actinolite
in great variety, bronzite, green feldspar, moonstone, sunstone, graphic
granite, magnesite, octahedral crystals of chromite in great quantity,
beryl, chalcedony, asbestus, fibrous hornblende, rutile, staurolite, ine-
lanosiderite, hallite ; at Painter's Farm, near Dismal Run, zircon with
oligoclase, tremolite, tourmaline ; at, the Black Horse, near Media,
corundum ; at Hibbard's Farm and at Fairlamb's Hill, chromite in.
brilliant octahedrons.
NEWTOWN. — Serpentine, hematite, enstatite, tremolite.
UPPER PROVIDENCE. — Anthophyllite, tremolite, radiated asbestus,
radiated actinolite, tourmaline, beryl, green feldspar, amethyst (one
found on Morgan Hunter's farm weighing over 7 Ibs.), andalusite!
(one terminated crystal found on the farm of Jas. Worrell weighs 7£
Ibs. ) ; at Blue Hill, very fine crystals of blue quartz in chlorite, amian-
thus in serpentine, zircon.
LOWER PROVIDENCE. — Amethyst, green mica, garnet, large crystals
of feldspar ! (some over 100 Ibs. in weight).
RADNOR. — Garnet, marmolite, deweylite, chromite, asbestus, mag-
nesite, talc, blue quartz, picrolite, limonite, magnetite.
SPRINGFIELD. — Andalusite, tourmaline, beryl, titanic iron, garnet ;
on Fell's Laurel Hill, beryl, garnet ; near Beattie's mill, staurolite,
apatite ; near Lewis's paper-mill, tourmaline, mica.
THORNBURY. — Amethyst.
HUNTINGDON CO.— NEAR FRANKSTOWN.— In the bed of a stream
and on the side of a hill, fibrous celestite (abundant), quartz crystals.
LANCASTER CO.— DRUMORE TOWNSHIP.— Quartz crystals.
FULTON. — At Wood's chrome mine, near the village of Texas, bru-
citelf zaratite (emerald nickel), pennite! ripidolite! Mmmererite!
baltimorite, chromite, williamsite, chrysolite! marmolite, picrolite^
hydromagnesite, dolomite, magnesite, aragonite, calcite, serpentine,
hematite, menaccanite, genthite, chrome-garnet, bronzite, millerite ;
at Low's mine, hydromagnesite, brucite (lancasterite), picrolite, magne-
site, williamsite, chromic iron, talc, zaratite, balumorite, serpentine,
hematite ; on M. Boice's farm, one mile N. W. of the village, pyrite in
cubes and various modifications, anthophyllite; near Rock Springs,
chalcedony, carnelian, moss agate, green tourmaline in talc, titanic iron,
chromite, octahedral magnetite in chlorite; at Reynolds's old mine,
calcite, talc, picrolite, chromite ; at Carter's chrome mine, brookitc.
GAP MINES. — Chalcopyrite, pyrrhotite (niccoliferous), millerite in
botryoidal radiations, mvianite I (rare), actinolite, siderite, hisingerite,
pyrite.
PEQUA VALLEY.— Eight miles south of Lancaster, argentiferous
galenite (said to contain 250 to 300 ounces of silver to the ton?), vau-
.quelinite, rutile at Pequea mine ; four miles N. W. of Lancaster,, on
354 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
the Lancaster and Harrisburg Railroad, calamite, galenite, blende;
pyrite in cubic crystals is found iu great abundance near the city of
Lancaster ; at the Lancaster zinc mines, calamine, blende, tennantite ?
smithsonite (pseud, of dolomite), aurichalcite.
LEBANON CO. — CORNWALL. — Magnetite, pyrite (cobaltif erous\
chalcopyrite, native copper, azurite, malachite, chrysocolla, cuprite (hy-
drocuprite), allophane, brochantite, serpentine, quartz pseudomorphs ;
galenite (with octahedral cleavage), fluorite, covellite, hematite (mica-
ceous), opal, asbestus.
LEHIGH CO. — FRIEDENSVILLE. — At the zinc mines, calamine,
smithsonite, hydrozincite, massive blende, greenockite, quartz, allo-
phane, zinciferous clay, mountain leather, aragonite, sauconite ; near
Allentown, magnetite, pipe-iron ore ; near Bethlehem, on S. Mountain,
allanite, with zircon and altered sphene in a single isolated mass of
syenite, magnetite, martite, black spinel, tourmaline, chalcocite.
MIFFLIN CO.— Strontianite.
MONROE CO. — In CHERRY VALLEY. — Calcite, chalcedony, quartz;
in Poconac Valley, near Judge Mervine's, cryst. quartz.
MONTGOMERY CO. — CONSHOHOCKEN. — Fibrous tourmaline, me-
naccanite, aventurine quartz, phyllite ; in the quarry of Geo. Bullock,
calcite in hexagonal prisms, aragonite.
LOWER PROVIDENCE. — At the Perkiomen lead and copper mines,
near the village of Shannonville, azurite, blende, galenite, pyromor-
phite, cerussite, wulfenite, anglesite, barite, calamine, chalcopyrite,
malachite, chrysocolla, brown spar, cuprite, covellite (rare), melaco-
nite. libethenite, pseudomalachite.
WHITE MARSH. — At D. O. Hitner's iron mine, five and a half miles
from Spring Mills, limonite in geodes and stalactites, gothite, pyro-
lusite, wad, lepidocrocite ; at Edge Hill Street, North Pennsylvania
Railroad, titanic iron, braunite, pyrolusite ; one mile S. W. of Hitner's
iron mine, limonite, velvety, stalactitic, and fibrous, fibres three inches
long, turgite, gothite, pyrolusite, velvet manganese, wad ; near Marble
Hall, at Hitner's marble quarry, white marble, granular barite, resem-
bling marble ; at Spring Mills, limonite, pyrolusite, gflthite ; at Flat
Rock Tunnel, opposite Manayunk, stilbite, lieulandite, chabasite, ilvaite,
beryl, feldspar, mica.
LAFAYETTE, at the Soapstone quarries. — Talc, jefferisite, garnet,
albite, serpentine, zoisite, staurolite, chalcopyrite ; at Rose's Serpen-
tine quarry, opposite Lafayette, enstatite, serpentine.
NORTHAMPTON CO.— BUSHKILL TOWNSHIP.— Crystal Spring on
Blue Mountain, quartz crystals.
Near E ASTON. — Zircon! (exhausted), nephrite, coccolite, tremolite,
pyroxene, sahlite, limonite, magnetite, purple calcite.
WILLIAMS TOWNSHIP. — Pyrolusite in geodes in limonite beds,
go'thite (lepidocrocite) at Glendon.
NORTHUMBERLj
.AND CO.— Opposite SELIN'S GROVE. —Cala-
mine.
PHILADELPHIA CO.— FRANKPORD.— Titanite in gneiss, apophyl-
lite ; on the Philadelphia, Trenton and Connecting Railroad, basanite;
at the quarries on Frankford Creek, stilbite, molybdenite, hornblende;
on the Connecting Railroad, wad, earthy cobalt ; at Chestnut Hill,
magnetite, green mica, chalcopyrite, fluorite.
FAIBMOUNT WATER- WORKS. — In the quarries opposite Fainnount,
CATALOGUE OP AMERICAN LOCALITIES OF MINERALS. 355
autunite ! torbernite, crystals of feldspar, beryl, pseudomorphs after
beryl, tourmaline, albite, wad, menaccanite.
GORGAS'S and CREASE'S LANE.— Tourmaline, cyanite, staurolite,
hornstone.
Near GERMANTOWN. — Black tourmaline, laumontite, apatite; York
Road, tourmaline, beryl.
HESTONVILLE. — Alunogen, iron alum, ortlioclase.
HEFT'S MILL. — Alunogen, tourmaline, cyanite, titanite.
MANAYUNK. — At the soapstone quarries above Manayunk, talc,
steatite, chlorite, vermiculite, anthophyllite, staurolite, dolomite, apa-
tite, asbestus, brown spar, epsomite.
MEGARGEE'S Paper-mill. — Staurolite, titanic iron, hyalite, apatite,
green mica, iron garnets in great abundance.
MCKINNEY'S QUARRY, on Rittenhouse Lane.— Feldspar, apatite, stil-
Ute, natrolite, heulandite, epidote, hornblende, erubescite, malachite.
SCHUYLKILL FALLS. — Chabazite, titanite, fluorite, epidote, musco-
vite, tourmaline, prochlorite.
SCHUYLKILL CO.— TAMAQUA, near POTTSVILLE, in coal mines.—
Kaolinite.
YORK CO. — Bornite, rutile in slender prisms in granular quartz.
DELAWARE.
NEWCASTLE CO. — BRANDYWINE SPRINGS.— Bucholzite, fbrolite
abundant, sahlite, pyroxene ; Brandywine Hundred, muscovite, en-
closing reticulated magnetite.
DIXON'S FELDSPAR QUARRIES, six miles N. W. of Wilmington
(quarries worked for the manufacture of porcelain). — Adularia, albite,
oligoclase, beryl, apatite, cinnamon-stone ! ! magnesite, serpentine, as-
bestus, black tourmaline ! (rare), indicolite ! (rare), sphene in pyroxene,
cyanite.
DUPONT'S POWDER MILLS.—" Hypersthene."
EASTBURN'S LIMESTONE QUARRIES, near the Pennsylvania line. —
Tremolite, Ironzite.
QUARRYVILLE.— Garnet, spodumene, fibrolite.
Near NEWARK, on the railroad. — Sphserosiderite on drusy quartz,
jasper (ferruginous opal), cryst. spathic iron in the cavities of cellular
quartz.
WAY'S QUARRY, two miles south of Centreville. — Feldspar in fine
cleavage masses, apatite, mica, deweylite, granular quartz.
WILMINGTON.— In Christiana quarries, metattoidal diallage.
KENNETT TURNPIKE, near Centreville. — Cyanite and garnet.
HARTFORD CO.— Deweylite.
KENT CO.— Near MIDDLETOWN, in Wm. Folk's marl pits.— Fm-
anite !
On CHESAPEAKE AND DELAWARE CANAL.— Retinasphalt, pyrite,
amber.
SUSSEX CO.— Near CAPE HENLOPEN.— Vivianite.
MARYLAND.
BALTIMORE (Jones's Falls, If mile from B.). — Chabazite (haydenite),
heulandite (beaumontite of Levy), pyrite, lenticular carbonate of iron,
mica, stilbite.
356 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
Sixteen miles from Baltimore, on the Gunpowder. — Graphite.
Twenty-three miles from 13., on the Gunpowder. — Talc.
Twenty-five miles from B., on the Gunpowder. — Magnetite, sphene,
pycnite.
Thirty miles from B., in Montgomery Co., on farm of S. Eliot. —
Gold in quartz.
Eight to twenty miles north of B., in limestone. — Tremolite, augite,
pyrite, brown and yellow tourmaline.
Fifteen miles north of B. — Sky-blue chalcedony in granular lime-
stone.
Eighteen miles north of B., at Scott's mills. — Magnetite, cyanite.
BAKE HILLS. — Chromite, asbestus, tnmolite, talc, hornblende, ser-
pentine, chalcedony, meerschaum, baltimorite, chalcopyrite, mag-
netite.
CAPE SABLE, near Magothy R. — Amber, pyrite, alum slate.
CARROLL Co. — Near Sykesville, Liberty Mines, gold, magnetite,
pyrite (octahedrons), chalcopyrite, linnseite (carrollite) ; at Patapsco
Mines, near Finksburg, bornite, malachite, siegenite, linnceite, reming-
tonite, magnetite, chalcopyrite ; at Mineral Hill mine, bornite, chalco-
pyrite, ore of nickel (see above), gold, magnetite.
CECIL Co., north part. — Chromite in serpentine.
COOPTOWN, Harford Co.— Olive-colored tourmaline, diallage, talc of
green, blue, and rose colors, lirniform asbestus, chromite, serpentine.
DEER CREEK. — Magnetite! in chlorite slate.
FREDERICK Co. — Old Liberty mine, near Liberty Town, black cop-
per, malachite, chalcocite, specular iron ; at Dollyhyde mine, bornite,
chalcopyrite, pyrite, argentiferous galenite in dolomite.
MONTGOMERY Co. — Oxide of manganese.
SOMERSET and WORCESTER Cos., north part. — Bog-iron ore, mvi-
anite.
ST. MARY'S RIVER. — Gypsum! in clay.
PYLESVILLE, Harford Co. — Asbestus mine.
VIRGINIA, WEST VIRGINIA, AND DISTRICT OF COLUMBIA.
ALBEMABLE Co., a little west of the Green Mts. — Steatite, graphite,
galenite.
AMHERST Co. — Along the west base of Buffalo Ridge, copper ores;
on N. W. slope of Friar Mtn., allanite, magnetite, zircon, sipylite.
AUGUSTA Co. — At Weyer's (or Weir's) cave, sixteen miles north-
east of Staunton, and eighty -one miles northwest of Richmond, cal-
cite, stalactites.
BLCKINCHAM Co. — Gold at Garnett and Moseley mines, also, pyrite,
pyrrhotite, calcite, garnet ; at Eldridge mine (now London and Vir-
ginia mines) near by, and the Buckingham mines near Maysville, gold,
auriferous pyrite, chalcopyrite, tennantite, barite ; cyanite, tourmaline,
actinolite.
CHESTERFIELD Co. — Near this and Richmond Co., bituminous coal,
native coke.
CULPEPPER Co., on Rapidan River. — Gold, pyrite.
FRANKLIN Co. — Grayish steatite.
FAUQUIER Co., Barnett's mills. — Asbestus, gold mines, barite, cat-
cite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 357
FLUVANNA Co. — Gold at Stockton's mine ; also tetradymite, at
" Tellurium mine."
PHENIX COPPER MINES. — Chalcopyrite, etc.
GEORGETOWN, D. C. — Rutile.
GOOCHLAND Co. — Gold mines (Moss and Busby's).
HARPER'S FERRY, on both sides of the Potomac. — Thuringite (owen-
ite) with quartz.
JEFFERSON Co., at Shepherdstown. — Fluor.
KANAWHA Co. — At Kauavvha, petroleum, brine springs, cannel coal.
LOUDON Co. — Tabular quartz, drase, pyrite, talc, chlorite, soapstone,
asbestus, chromite, actinolite, quartz crystals ; micaceous iron, boruite,
malachite, epidote, near Leesburg (Potomac mine).
LOUISA Co. — Walton gold mine, gold, pyrite, chalcopyrite, argen-
tiferous galenite, siderite, blende, anglesite ; boulangerite, blende (at
Tinder's mine).
NELSON Co. — Galenite, chalcopyrite, malachite.
ORANGE Co. — Western part, Blue Ridge, specular iron ; gold at the
Orange Grove and Vaucluse gold mines, worked by the " Freehold "
and " Liberty " Mining Companies.
ROCKBRIDGE Co., three miles southwest of Lexington. — Barite,
etrengite.
SIIENANDOAH Co.. near Woodstock.— Fluorite.
MT. ALTO, Blue Ridge. — Argillaceous iron ore.
SPOTTSYLVANIA Co., two miles northeast of Chancellorville.— Cy-
anite ; gold mines at the junction of the Rappahannock and Rapidan ;
on the Rappahanuock (Marshall mine); Whitehall mine, affording
also tedradymite.
STAFFORD Co., eight or ten miles from Falniouth. — Micaceous iron,
gold, tedradymite, silver, galenite, vivianite.
WASHINGTON Co., eighteen miles from Abingdon.— Rock salt with
gypsum.
WYTHE Co. (Austin's mines). — Cerussite, minium, plumbic ochre,
blende, calamine, galenite, graphite.
On the Potomac, twenty-five miles north of Washington City.— Na-
tive sulphur in gray compact limestone.
NORTH CAROLINA.
ASHE Co. — Malachite, chalcopyrite.
BUNCOMBE Co. (now called Madison Co.) — Corundum (from a boul-
der), margarite, corundophilite, garnet, chromite, barite, fluoi*ite, ru-
tile, iron ores, manganese, zircon ; at Swananoa Gap, cyanite.
BURKE Co. — Gold, monazite, zircon, beryl, corundum, gar net, sphene,
graphite, iron ores, tetradymite, montanite (hydrous bismuth tellurate).
CABARRUS Co. — Phenix Mine, gold, barite, chalcopyrite, auriferous
pyrite, -quartz pseudomorph after barite, tetradymite, montanite ; Pi-
oneer mines, gold, limonite, pyrolusite, barnhardite, wolfram, scheelite,
cuprotungstite, tungstite, diamond, chrysocolla, chalcocite, molybde-
nite, chalcopyrite, pyrite ; White mine, needle ore, chalcopyrite, ba-
rite ; Long and Muse's mine, argentiferous galenite, pyrite, chalcopy-
rite, limonite ; Boger mine, tetradymite ; Fink mine, valuable copper
ores ; Mt. Makins, tetrahedrite, magnetite, talc, blende, pyrite, prous-
tite, galenite ; Bangle mine, scheelite.
358 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
CALDWELL Co. — Chromite.
CHATHAM Co. — Mineral coal, pyrite, cliloritoid.
CHEROKEE Co. — Iron ores, gold, galenite, corundum, rutile, cyanite,
dainonite.
CLEVELAND Co. — White Plains, quartz, crystals, smoky quartz, tour-
maline, rutile in quartz.
CLAY Co. — At the Cullakenee mine and elsewhere, corundum (pink),
zoisite, tourmaline, margarite, willcoxite, dudleyite.
DAVIDSON Co. — King's, now Washington mine, native silver, cerus-
site, anglesite, scheelite, pyromorphite, galenite, blende, malachite,
black copper, wavellite, garnet, stilbite ; five miles from Washington
mine, on Faust's .farm, gold, tetradymite, oxide of bismuth and tellu-
rium, montanite, chalcopyrite, limonite, spathic iron, epidote ; near
Squire Ward's, gold in crystals, electrum.
FRANKLIN Co. — At Partiss mine, diamonds.
GASTON Co. — Iron ores, corundum, margarite ; near Crowder's Moun-
tain (in what was formerly Lincoln Co.), lazulite, cyanite, garnet, gra-
phite ; also twenty miles northeast, near south end of Clubb's Moun-
tain, lazulite, cyanite, talc, rutile, topaz, pyrophyllite ; King's Moun-
tain (or Briggs) mine, native tellurium, altaite, tedradymite, monta-
nite.
GUILFORD Co. — McCulloch copper and goldmine, twelve miles from
Greensboro', gold, pyrite, chalcopyrite (worked for copper), quartz, sid-
erite ; copper ore at the old Fentress mine ; at Deep River, compact
pyrophyllite (worked for slate-pencils),
HAYWOOD Co. — Corundum, margarite, damourite.
HENDERSON Co. — Zircon, sphene (xanthitane).
JACKSON Co. — Alunogen ? at Smoky Mountain ; at Webster, serpen-
tine, chromite, genthite, chrysolite, talc ; Hoghalt Mountain, pink co-
rundum, margarite, tourmaline.
LINCOLN Co.— Diamond ; at Randleman's, amethyst, rose quartz.
MACON Co.— Franklin, Culsagee mine, corundum, spinel, diaspore,
tourmaline, damourite, prochlorite, cnlsageeite, kerrite, maconite.
MCDOWELL Co. — Brookite, monazite, corundum in small crystals,
red and white, zircons, garnet, beryl, sphene, xenotime, rutile, elastic
sandstone, iron ores, pyromelane, tetradymite, montanite.
MADISON Co. — Twenty miles from Asheville, corundum, margarite,
chlorite.
MECKLENBURG Co. — Near Charlotte (Rhea and Cathay mines) and
elsewhere, chalcopyrite, gold; chalcotrichite at McGinn's mine; barn-
hardtite near Charlotte ; pyrophyllite in Cotton Stone Mountain, dia-
mond ; Flowe mine, scheelite, wolframite ; Todd's Branch, monazite.
MITCHELL Co. — At the Wiseman mica mine, muscovite samarskite,
hatchettolite, euxenite, columbite, rogersite, uraninite, gummite, ura-
conite, torbernite, autunite ; at Grassy Creek mine, muscomte, samara-
kite.
MONTGOMERY Co. — Steele's mine, ripidolite, albite.
MOORE Co. — Carbon ton, compact pyrophyllite.
ROWAN Co.— Gold Hill mines, thirty-eight miles northeast of Char-
lotte, and fourteen from Salisbury, gold, auriferous pyrite ; ten miles
from Salisbury, feldspar in crysteils.bismuthmite.
RANDOLPH Co.— Pyrophyllite.
RUTHERFORD Co.— Gold, graphite, bismuthic gold, diamond, euclase,
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 359
pseudomorphous quartz? chalcedony, corundum in small crystals, epi-
dote, pyrope, brookite, zircon, monazite, rutherfordite, samarskite,
quartz crystals, itacolumyte ; on the road to Cooper's Gap, cy anile.
STOKES and SURKY Cos. — Iron ores, graphite.
UNION Co. — Lemmond gold mine, eighteen miles from Concord (at
Stewart's and Moore's mine), gold, quartz, blende, argentiferous gale-
nite (containing 29 '4 oz. of gold and b6'5 oz. of silver to the ton, Genth),
pyrite, some chalcopyrite.
YANCEY Co. — Iron ores, amianthus, cliromite, garnet (spessartite),
samarskite, columbite.
SOUTH CAROLINA.
ABBEVILLE DIST. — Oakland Grove, gold (Dora mine), galenite, pyro-
morphite, amethyst, garnet.
ANDERSON DIST. — At Pendleton, actinolite, galenite, kaolin, tourma-
line.
CHARLESTON. —Selenite.
CHEOWEE VALLEY.— Galenite, tourmaline, gold.
CHESTERFIELD DIST. — Gold (Brewer's mine), talc, chlorite, pyrophyJ-
lite, pyrite, native bismuth, bismuth carbonate, red and yellow ochre,
whetstone, enargite.
DARLINGTON. — Kaolin.
EDGEFIELD DIST. — Psilomelane,
GREENVILLE DIST.— Galenite, pyromorphite, kaolin, chalcedony in
buhrstone, beryl, plumbago, epidote, tourmaline.
KERSHAW DIST. — Rutile.
LANCASTER DIST. — Gold (Hale's mine), talc, chlorite, cyanite, ita-
columyte, pyrite ; gold also at Blackmail's mine, Massey's mine,
Ezell's mine.
LAURENS DIST.— Corundum, damourite.
NEWBERRY DIST.— Leadhillite.
PICKENS DIST. — Gold, manganese ores » kaolin,
HIGHLAND DIST. — Chiastolite, novaculite.
SPARTANBURG DIST. — Magnetite, chalcedony, hematite ; at the Cow-
pens, limonite, graphite, limestone, copperas ; Morgan mine, leadhil-
lite, pyromorphite, cerussite.
SUMTER DIST. — Agate.
UNION DIST. — Fairforest gold mines, pyrite, chalcopyrite.
YORK DIST. — Limestones, whetstones, witherite, barite, tetrady-
mite.
GEORGIA.
BURKE AND SCRIVEN Cos.— Hyalite.
CHEROKEE Co. — At Canton Mine, chalcopyrite, galenite, claustha-
lite, plumbogummite, hitchcockite, arsenopyrite, lanthanite, harrisite,
cantonite, pyromorphite, automolite, zine, staurolite, cyanite ; at Ball-
Ground, spodumene.
CLARK Co., near Clarksville.— Gold, xenotime, zircon, rutile, cyanite,
hematite, garnet, quartz.
DADE Co. — Halloysite, near Rising Fawn.
FANNIN Co.— Staurolite ! chalcopyrite.
360 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
HABERSHAM Co. — Gold, pyrite, chalcopyrite, galenite, hornblende,
garnet, quartz, kaolinite, soapstone, chlorite, rutile, iron ores, tourma-
line, staurolite, zircon.
HALL Co. — Gold, quartz, kaolin, diamond.
HANCOCK Co. —Agate, chalcedony.
HEARD Co. — Molubdite, quartz.
LEE Co. — At the Chewacla Lime Quarry, dolomite, barite, quartz
crystals.
LINCOLN Co. — Lazulite ! ! rutile! ! hematite, cyanite, manaccanite,
pyrophyllite, gold, itacolumyte rock.
LOWNDES Co. — Corundum.
LUMPKIN Co. — At Field's gold mine, near Dahlonega, gold, tetrady-
mite, pyrrhotite, chlorite, menaccanite, allanite, apatite.
RABUN Co. — Gold, ckalcopyrite.
SPAULDING Co. — Tetradymite.
. WASHINGTON Co., near Saundersville. — Wavellite, fire opal.
ALABAMA.
BENTON Co. — Antimonial lead ore (boulangerite ?)
BIBB Co., Centreville. — Iron ores, marbl , barite, coal, cobalt.
CHAMBERS Co. — Near La Fayette, steatite, garnets, actinolite, chlo-
rite ; east of Oak Bowery, steatite.
CHILTON Co — Muscovite, graphite, limonite.
CLEBURNE Co. — At Arbacoochee mine, gold, pyrite, and three miles
distant cyanite, garnets ; at Wood's min black copper, azurite, chalco-
pyrite, pyrite.
CLAY Co. — Steatite ; near Delta and Ashland, muscovite.
Coos A Co. — Tantalite, gold, muscovite.
RANDOLPH Co. — Gold, pyrite, tourmaline, muscovite ; at Louina,
porcelain clay, gar et.
TALLADEGA C..— Limonite.
TALLAPOOSA Co. at Dudley ville.— Corundum, margarite, ripidolite,
spinel, tourmaline, actinolite, steatite, asbestus, chrysolite, damourite,
corundum altered to tourmaline (crystals of the latter containing a
nucleus of the former) and also other pseudomorphs, including, at
Dudleyville, dudleyite.
TUSKALOOSA Co. — Goal, galenite, pyrite, vivianite, limonite, calcite,
dolomite, cyanite, steatite, quartz crytals, manganese ores.
FLORIDA.
NEAR TAMPA BAY. — Limestone, sulphur springs, chalcedony,
carnelian, agate, silicified shells and corals.
KENTUCKY.
ANDERSON Co. —Galenite, barite.
CLINTON Co. — Geodes of quartz.
CBITTENDEN Co. — Galenite, fluorite, calcite.
EDMONDSON Co. — At Mammoth Cave, gypsum, rosettes ! calcite, sta-
lactites, nitre, epsomite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 361
FAYETTE Co. — Six miles N. E. of Lexington, galenite, barite,
witherite, blende.
LIVINGSTON Co. , near the line of Union Co. — Galenite, chalcopyrite,
large vein of fluorite.
MERCER Co. — At McAfee, fluorite, pyrite, calcite, barite, celestite.
OWEN Co. — Galenite, barite.
TENNESSEE.
BROWN'S CREEK.— Galenite, blende, barite, celestite.
CARTER Co., foot of Roan Mt. — Sahlite, magnetite.
CLAIBORNE Co. — Calamine, galenite, sinithsonite, chlorite, steatite,
magnetite.
COCKE Co., near Bush Creek. — Cacoxenite? kraurite, iron sinter,
stilpnosiderite, brown hematite.
DAVIDSON Co.- Selenite, with granular and snowy gypsum, or ala-
baster, crystallized and compact anhydrite, jtuorite in crystals ? calcite
in crystals. Near Nashville, blue celestite (crystallized, fibrous, and
radiated), with barite in limestone. Haysboro', galenite, blende, with
barite as the gangue of the ore.
DICKSON Co.— Manganite.
JEFFERSON Co. — Calamine, galenite, fetid barite.
KNOX Co. — Magnesian limestone, native iron, variegated marbles!
MAURY Co. — Wavellite in limestone.
MORGAN Co. — Epsom salt, nitrate of lime.
POLK Co., Ducktown mines, southeast corner of State. — Melaconite,
chalcopyrite, pyrite, native copper, bornite, rutile, zoisite, galenite, har-
risite, alisonite, blende, pyroxene, tremolite, sulphates of copper and
iron in stalactites, allophane, rahtite, chalcocite (ducktownite), chal-
cotrichite, azurite, malachite, pyrrhotite, limonite.
ROAN Co., easterly declivity of Cumberland Mts.— Wavellite in
limestone.
SEVIER Co., in caverns. — Epsomite, soda alum, nitre, nitrate of
calcium, breccia marble.
SMITH Co.— Fluorite.
SMOKY MT., on declivity. — Hornblende, garnet, staurolite.
WHITE Co.— Nitre.
OHIO.
BAINBRIDGE (Copperas Mt., a few miles east of B.). — Calcite, barite,
pyrite, copperas, alum.
CANFIELD. — Gypsum !
DUCK CREEK, Monroe Co. — Petroleum.
LAKE ERIE. — Strontian Island, celestite! Put-in-Bay Island, celestite!
sulphur! calcite.
LIVERPOOL. — Petroleum.
MARIETTA. — Argillaceous iron ore • iron ore abundant also in Scioto
and Lawrence Cos.
OTTAWA Co. — Gypsum.
POLAND. —Gypsum !
362 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
MICHIGAN.
BREST (Monroe Co.). — Calcite, amethystine quartz, apatite, celestite.
GRAND RAPIDS. — ISelenite, fib. and granular gypsum, calcite, dolomite,
anhydrite.
LAKE SUPERIOR MINING REGION. — The four principal regions are
Keweenaw Point, Isle Royale, the Ontonagon, and Portage Lake.
The mines of Keweenaw Point are along two ranges of elevation, one
known as the Greenstone Range, and the other as the Southern or
Bohemian Range (Whitney). The copper occurs in the trap or amyg-
daloid, and in the associated conglomerate. Rat-foe copper! native
silver! chalcopyrite, horn silver, tetrahedrite, manganese ores, epi-
dote, prchnite, laumontite, datolite, heulandite, orthoclase, analcite, cha-
bazite, compact datolite, chrysocolla, mcsotype (Copper Falls mine),
leonhardite (ib.), analcite (ib.), apophyllite (at Cliff mine), wollastonite
(ib.), calcite, quartz (in crystals at Minnesota mine), compact datolite,
orthoclase (Superior mine), saponite, melaconite (near Copper Harbor,
but exhausted), chrysocolla ; on Chocolate River, galenite and sul-
phide of copper ; chalcopyrite and native copper at Presq'lsle ; at
Albion mine, domeykite ; at Prince Vein, barite, calcite amethyst ; at
Albany and Boston mine, Portage Lake, prehnite, analcite, orthoclase,
cuprite ; at Sheldon location, domeykite, whitneyite, algodonite ; Quincy
mine, calcite, compact datolite. At the Spur Mountain iron mine
(magnetite), chlorite pseudomorph after garnet ; Isle Royale, datolite,
prehnite.
MARQUETTE. — Manganite, galenite ; twelve miles west at Jackson
Mt., and other mines, hematite, limonite, gbthite! magnetite, jasper.
MONROE. — Aragonite, apatite.
POINT AUX PEAUX (Monroe Co.) — Amethystine quartz, apatite, celes-
tite, calcite.
SAGINAW BAY. — At Alabaster, gypsum.
STONY POINT (Monroe Co.) — Apatite, amethystine quartz, celestite,
calcite.
ILLINOIS.
GALLATIN Co., on a branch of Grand Pierre Creek, sixteen to thirty
miles from Shawneetown, down the Ohio, and from half to eight
miles from this river. — Violet fiuorite! in carboniferous limestone,
barite, galenite, blende, brown iron ore.
HANCOCK Co. — At Warsaw, quartz geodes containing calcite ! chal-
cedony, dolomite, blende ! brown spar, pyrite, aragonite, gypsum, bitu-
men.
HARDIN Co. — Near Rosiclare, calcite, galenite, blende ; five miles
back from Elizabethtown, bog iron ; one mile north of the river, be-
tween Elizabethtown and Rosiclare, nitre.
Jo DAVIESS Co.— At Galena, galenite, calcite, pyrite, blende ; at Mars-
den's diggings, galenite ! blende, cerussite, marcasite in stalactitic form*
pyrite.
JOLIET. — Marble.
QUINCY.— Calcite! pyrite.
SCALES MOUND. — Barite, pyrite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 363
INDIANA.
LIMESTONE CAVERNS ; Corydon Caves, etc. — Epsom salt.
In most of the southwest counties, pyrite, iron sulphate, and feather
alum; on Sugar Creek, pyrite and iron sulphate ; in sandstone of Lloyd-
Co., near the Ohio, gypsum ; at the top of the blue limestone forma
tion, brown spar, calcite.
LAWRENCE Co. — Spice Valle, kaolinite (=indianaite).
MINNESOTA.
NORTH SHORE OF L. SUPERIOR (ranjre of hills running nearly north
east and southwest, extending from Fond du Lac Superieure to thf
Kamanistiqueia River in Upper Canada). — Scolecite, apophyllite. preh-
nite, stilbite, laumontite, heulandite, harmotome, thomsonite, fluorite,
barite, tourmaline, epidote, hornblende, calcite, quartz crystals, pyrite,
magnetite, steatite, blende, black oxide of copper, malachite, native
copper, chalcopyrite, amethystine quartz, ferruginous quartz, ehalce-
dony, carnelian, agate, drusy quartz, hyalite? fibrous quartz, jasper,
prase (in the debris of the lake shore), dogtooth spar, augite, native
silver, spodumene? chlorite ; between Pigeon Point and Fond du Lac,
near Baptism River, saponite (thalite) in amygdaloid.
KETTLE RIVER TRAP RANGE.— Epidote, nail-head calcite, amethys-
tine quartz, calcite, undetermined zeolites, saponite.
STILL WATER. — Blende.
FALLS OF THE ST. CROIX. — Malachite, native copper, epidote, nail-
head spar (calcite).
RAINY LAKE. — Actinolite, tremolite, fibrous hornblende, garnet, py-
rite, magnetite, steatite.
WISCONSIN.
BIG BULL FALLS (near). — Bog iron.
BLUE MOUNDS.— Cerussite.
HAZEL GREEN. — Calcite.
LAC DU FLAMBEAU R. — Garnet, cyanite.
LEFT-HAND R. (near small tributary). — Malachite, chalcocite, native
copper, cuprite, malachite, epidote, chlorite? quartz crystals.
LINDEN. — Oalenite, smithsonite, hydrozindte.
MINERAL POINT and vicinity. — Copper and lead ores, chrysocolla,
azuritef chalcopyrite, malachite, galenite. cerussite, anglesite, blende,
py)"ite, barite, calcite, marcasite, smithsonite! (including pseudomorphs
after calcite and blende), (so-called " dry-bone "), calamine, bornite,
hydrozincite.
MONTREAL RIVER PORTAGE. — Galenite in gneissoid granite.
SAUK Co. — Hematite, malachite, chalcopyrite.
SHULLSBURG. — Galenite ! blende, pyrite ; at Emmet's digging, ga-
lenite and pyrite.
IOWA.
Du BUQUE LEAD MINES, and elsewhere. — Galenite f calcite, blende,
black oxide of manganese ; at Ewing's and Sherard's diggings, smith'
364 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
sonite, calami ne ; at Des Moines, quartz crystals, selenite ; Makoqueta
R., limonite ; near Durango, galenite.
CEDAU RIVER, a branch of the Des Moines. — Selenite in crystals, in
the bituminous shale of the coal measures ; also elsewhere on the Des
Moines, gypsum abundant ; argillaceous iron ore, spathic iron ; cop-
peras in crystals on the Des Moines, above the mouth of Saap and else-
where, pyrite, blende.
FORT DODGE. — Celestite.
MAKOQUETA. — Hematite.
NEW GALENA. — Octahedral galenite, anglesite.
MISSOURI.
For the distribution of the lead mines see page 147. The number
of minerals associated with the lead ore varies greatly in the different
lead regions. Mine la Motte. and some old openings in Madison C'o.,
are peculiar in affording cobalt and nickel ores abundantly. At Granby
and other mines the chief zinc ore is calamine, or the silicate of zinc,
while in the mines of Central and Southwest Missouri it is compara-
tively rare, and smithsonite is the prominent ore — as is the case in.
Wisconsin ; yet calamine is the most abundant zinc ore in the State.
As stated by A. Schmidt, the zinc ore, in each case, is found as a sec-
ondary product to sphalerite (blende) ; the cerussite often coats the
galenite, or has its forms, indicating thus its source ; the limonite is
also secondary, and has come in mainly through the oxidation of py-
rite. At the Granby mines, the calamine is called, among the miners,
" Black Jack ; " blende, " Resin Jack ; " a white massive smithsonite,
" White Jack ;" and the cerussite is the " Dry Bone ; " thus departing
from ordinary miners' usage. Gold has been found in the drift sands
of Northern Missouri (Broadhead).
ADAIR Co. — Gothite in calcite.
BARTON Co. — Pickeringite as an effloresence on sandstone.
CHARITON Co. — Near Salisbury, gypsum (selenite) in coal beds.
COLE Co. — At' Old Circle Diggings and elsewhere, barite! galenite,
chalcopyrite, malachite, azurite, pyrite, calcit*, calamine, sphalerite.
COOPER Co. — Collins Mine, malachite with azurite, etc.
DADE Co. — Smithsonite.
FRANKLIN Co. — Cove Mines, anglesite, galenite, cerussite, barite.
IRON Co. — At Pilot Knob and Shepherd Mountain, hematite, mag-
netite, limonite, manganese oxide, bog manganese.
JASPER Co. (adjoins S. E. Kansas). — At Joplin Mines, galena ! spha-
lerite, pyrite, cerussite, calamine, dolomite, bitumen.
JEFFERSON Co. — At Valle's, galenite ! cerussite, anglesite, calamine,
smithsonite, sphalerite, hydrozincite, chalcopyrite, malachite, azurite,
pyrite, barite, witherite, limonite. At Fruinet mines, 8.^ miles from
DeSoto R. R. station, galena, barite ! smithsonite ! pyrite, limnite.
MADISON Co. — At Mine la Motte, gulenite! cerussite! siegenite (nickel-
linnaeite), smaltite, asbolite (earthy black cobalt ore), bog manganese,
chalcopyrite, malachite, caledonite, plumbogummite, wolframite.
MORGAN Co. — At Cordray Diggings, galena, blende, barite.
NKWTON Co. (adjoins S. E. Kansas). — At Granby Mines, galenite!
cerusfiitc, calamine! sphalerite, smithsonite, hydrozincite, green-ockite
(on sphalerite), pyromorphite, dolomite, calcite, bitumen, buratite.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS. 365
ST. FRANCOIS Co — Iron Mountain, hematite, magnetite, limonite.
ST. Louis Co — Near St. Louis, millerite (in the Subcarboniferous
St. Louis limestone, largely a inagnesian limestone) with calcite ! ba-
rite, fluorUe.
WASHINGTON Co. — At Potosi, galenite, cerussile, anglesite, barite
ARKANSAS.
BATESVILLE. — In bed of White R., some miles above Batesville,
gold.
GREEN Co. — Near Gainesville, lignite.
HOT SPRINGS Co. — At Hot Springs, wavellite, thuringite; Magnet
Cove, brookite ! schorlomite, elceolite, magnetite, quartz, green coccolite,
garnet, apatite, perofskite (hydrotitanite), rutile, ripidolite, thomsouite
(ozarkite), microcline, cegirite, protovermiculite.
INDEPENDENCE Co. — Lafferay Creek, psilomelane.
LAWRENCE Co.— Hoppe, Bath, and Koch mines, smithsonite, dolo
mit<% galenite ; nitre.
MARION Co. — Wood's mine, smithsonite, hydrozincite (marionite)
galenite ; Poke bayou, braunite?
MONTGOMERY Co. — Variscite.
OUACHITA SPRINGS.— Quartz? whetstones.
PULASKI Co.— Kellogg mine, 10 in. north of Little Rock, tetrahedrite.
tennantite, nacrite, galenite, blende, quartz.
CALIFORNIA.
The principal gold mines of California are in Tulare, Fresno, Mari-
posa, Tuolumne, Calaveras, El Dorado, Placer, Nevada, Yuba, Sierra,
Butte, Plumas, Shasta, Siskiyou, and Del Norte counties, although
gold is found in almost every county of the State. The gold occurs in
quartz, associated with sulphides of iron, copper, zinc, and lead ; in
Calaveras and Tuolumne counties, at the Mellones, Stanislaus, Golden
Rule, and Rawhide mines, associated with tellurides of gold and sil-
ver ; it is also largely obtained from placer digrings, and further it is
found in beach washings in Del Norte and Klamath counties.
The copper mines are principally at or near Copperopolis, in Cala-
veras County; near Genesee Valley, in Plumas County; near Low
Divide, in Del Norte County ; on the north fork of Smith's River ; at
Soledad, in Los Angeles county.
The mercury mines are at or near New Almaden and North Al-
maden, in Santa Clara County ; at New Idria and San Carlos, Monterey
County ; in San Luis Obispo County ; at Pioneer mine, and other locali-
ties in Lake County ; in Santa Barbara County.
ALAMEDA Co. — Diabolo Range, magnesite.
ALPINE Co. — Morning Star mine, enargite, stephanite, polybasite,
barite, quartz, pyrite, tetrahedite, pyrargyrite.
AMADOU Co. — At Volcano, chalcedony, hyalite; Lone Valley, lonite;
Fiddletown, diamond.
BUTTE Co. — Cherokee Flat, diamond, platinum, iridosmine.
CALAVERAS Co. — Copperopolis, chalcopyrite, malachite, azurite, ser-
pentine, picrolite, native copper ; near Murphy's, jasper, opal ; albite,
with gold and pyrite ; Melloues mine, calaverite, petzite.
366 SUPPLEMENT TO DESCRIPTIONS OP SPECIES.
CoNTRA-CosTA Co. — San Antonio, chalcedony.
DEL NORTE Co. — Crescent City, agate, camel ian ; Low Divide, dial-
copy rite, bornite, malachite ; on the coast, iridosmine, platinum, gold,
zircon, diamond.
EL DORADO Co. — Pilot Hill, chalcopyrite; near Georgetown, hessite,
from placer diggings ; Roger's Claim, Hope Valley, grossular garnet,
in copper ore ; Coloma, chromite ; Spanish Dry Diggings, gold ; Gran-
ite Creek, roscoelite, gold ; Forest Hill, diamond ; Cosumues mine,
molybdenite.
FKESNO Co. — Chowchillas, andalusite ; King's River, bornite.
HUMBOLDT Co. — Cryptomorphite.
INTO Co. — Inyo district, galenite, cerussite, anglesite, barite, ataca-
mite, calcite, grossular garnet ! Surprise Mine, tetrahedrite ; Kear-
sarge mine, silver ores ; Cerro Gordo, wulfenite.
KERN Co. — Green Monster mine, cuproscheelite.
LAKE Co. — Borax Lake, borax! sassolite, glauberite; Pioneer mine,
cinnabar, native mercury, selenide of mercury ; near the Geysers,
sulphur, hyalite ; Redington mine, metacinnabarite ; Lower Lake,
chromite.
Los ANGELES Co. — Near Santa Anna River, anhydrite ; Williams
Pass, chalcedony ; Soledad mines, chalcopyrite, garnet, gypsum ;
Mountain Meadows, garnet, in copper ore.
MARIPOSA Co. — Chalcopyrite, itacolumyte ; Centreville, cinnabar ;
Pine Tree mine, tetrahedrite ; Burns Creek, limonite ; Geyer Gulch,
pyrophyllite ; La Victoria mine, azarite ! near Coulterville, cinnabar,
gold.
MONO Co. — Partzite (stibiconite).
MONTEREY Co. — Alisal mine, arsenic ; near Paneches, chalcedony ;
New Idria mine, cinnabar ; near New Idria, chromite, zaratite, chrome
garnet ; near Pacheco's Pass, stibnite.
NAPA Co. — Chromite.
NEVADA Co. — Grass Valley, gold! in quartz veins, with pyrite,
chalcopyrite, blende, arsenopyrite, galenite, quartz, biotite ; near
Truckee Pass, gypsum ; Excelsior Mine, molybdenite, with gold ;
Sweet Land, pyrolusite.
PLACER Co. — Miner's Ravine, epidote ! with quartz, gold.
PLUMAS Co. — Genesee Valley, chalcopyrite ; Hope mines, bornite,
sulphur.
SANTA BARBARA Co. — San Amedio Canon, stibnite, asphaltum, bitu-
men, maltha, petroleum, cinnabar, iodide of mercury ; Santa Clara
River, sulphur.
SAN BERNARDINO Co. — Colorado River, agate, trona ; Temescal
Mts. , cassiterite ; Russ District, galenite, cerussite ; Francis mine,
cerargyrite ; Slate Range, thenardite, borax, common salt ; San Ber-
nardino Mts. , graphites.
SANTA CLARA Co. — New Almaden, cinnabar, calcite, aragonite. ser-
pentine, chrysolite, quartz, aragotite ; North Almaden, chromite ; Mt.
Diabolo Range, magnesite, datolite, with vcsuvianite and garnet.
SAN DIEGO Co. — Carisso Creek, gypsum ; San Isabel, tourmaline
orthoclase, garnet.
SAN FRANCISCO Co. — Red Island, pyrolusite and manganese ores.
SAN Luis OBISPO Co. — Asphaltum, cinnabar, native mercury,
chromite.
CATALOGUE OF AMERICAN LOCALITIES OP MINERALS. 367
SHASTA Co. — Near Shasta City, hematite, in large masses.
SIERRA Co. — Forest City, gold, arsenopyrite, tellurides.
SISKIYOU Co. — Surprise Valley, selenite, in large slabs.
SONOMA Co. — Actinolite, garnets, chromite, serpentine.
TTJLARE Co. — Near Visalia, magnesite, asphaltum.
TUOLUMNE Co. — Tourmaline, tremolite ; Sonora, graphite ; Tori
Tent, chromite ; Golden Rule mine, petzite, calaverite, altaite, hessite,
magnesite, tetrahcdrite, gold ; Whiskey Hill, gold!
TRINITY Co. — Cassiterite, a single specimen found.
LOWER CALIFORNIA-
LA PAZ. — Cuproscheelite. LORETTO. — Natrolite, siderite, selenite.
UTAH.
BEAVER Co. — Bismuthinite, bismite, bismutite.
TINTIC DISTRICT. — At the Shoebridge mine, the Dragon mine, and
the Mammoth vein, enargite with pyrite.
Box ELDER Co. — Empire mine, wulfenite!
UTAH Co. — Ammonia alum.
In the Wahsatch and Oquirrh mountains there are extensive mines,
especially of ores of lead rich in silver. At the Emma mine occur
galenite, cervantite, cerussite, wulfenite, azurite, malachite, calamine,
anglesite, linarite, sphalerite, pyrite, argentite, stephanite, etc. At
the Lucky Boy mine, Butterfield Canon, orpiment, realgar.
One hundred and twenty miles southwest of Salt Lake City, topaz
has been found in colorless crystals. At a silver mine, fibrous se«
piolite.
NEVADA.
CARSON VALLEY. —Chrysolite.
CHURCHILL Co. — Near Ragtown, gay-lussite, trona, common salt.
COMSTOCK LODE. — Gold, native •silver, argentite, stephanite, polyba,
site, pyrargyrite, proustite, tetrahedrite, cerargyrite, pyrite, chalcopy
rite, galenite, blende, pyromorphite, allemontite, arsenolite, quartz,
calcite, gypsum, cerussite, cuprite, wulfenite, amethyst, kiistelite.
ELKO Co. — Emma Mine, chrysocolla.
ESMERALDA Co. — Alum, 12 m. north of Silver Creek ; at Aurora,
fluorite, stibnite ; near Mono Lake, native copper and cuprite, obsi-
dian; Thiel Salt Marsh, ulexite, borax, common salt, thenardite ;
Columbus district, ulexite, thenardite, sulphur ; Walker Lake, gyp-
sum, hematite ; Silver Peak, salt, saltpetre, sulphur, silver ores.
HUMBOLDT DISTRICT. — Sheba mine, native silver, jamesonite, stib-
nite, tetrahedrite, proustite, blende, cerussite, calcite, bournonite, py-
rite, galenite, malachite, xanthocone (?), cuprite.
LANDER Co. — Austin, polybasite, chalcopyrite, azurite.
LINCOLN Co. — Rock salt, cerargyrite.
MAMMOTH DISTRICT. — Ortkoclass, turquoise, Mbnerite, scheelite.
NYE Co.— Anglesite, stetefeldite, azurite, cerussite, silver
cerargyrite.
368 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
REESE RIVEK DISTRICT. — Native silver, proustite, pyrargyritc,
Btephanite, blende, polybasite, rhodochrosite, embolite, tetrahedrite !
cerargyrite, embolite.
SAN ANTONIA — Belinont mine, stetefeldtite.
SIX-MILE CANON. — Selenite.
ORMSBY Co. — W. of Carson, epidote.
STOREY Co. — Alum, natrolite, scolecite.
WHITE PINE Co. — Eberhardt mine, cerargyrite ; Paymaster mine
freieslebenite.
ARIZONA
To the south, south of Tucson, near the Mexican boundary, the re-
gion about Tubac Arivaca, the Santa Rita and the Patagonia Mts.,
noted for silver mines, the ore in part argentiferous galenite ; about
Tucson, copper ores ; a little to the north, the Heint/elmann mine,
Stromeyerite, chalcocite, tetrahedrite, native silver, atacamite ; on
and near the Colorado River, in Yuma County, the Castle Dome, Eu-
reka and other mines, of gold, silver, and copper, argentiferous gale-
nite the prominent silver ore. In the Penal range, gold ; on the San
Francisco River, native copper, covellite, chalcopyrite, malachite, azu-
rite ; at Bill Williams Fork, malachite, chrysocolla, atacamite, bro-
chantite ; Montgomery mine, Harsayampa district, tetradymite.
North of the Qila, just west of the boundary of New Mexico, chalco-
cite, cuprite, malachite.
OREGON AND WASHINGTON.
Gold is obtained from beach washings on the southern coast ; quartz
mines and placer mines in the Josephine district ; also on the Powder,
Burnt, and John Day's rivers, and other places in Eastern Oregon ;
platinum, iridosmine, laurite, on the Rogue River, at Port Orford,
and Cape Blanco. In Curry Co. , priceite.
At Seattle, Washington T. — Scheelite, tourmaline ; at Fidalgo,
realgar.
IDAHO.
In the Owyhee, Boise, and Flint districts, gold, also extensive silver
mines ; Poor Man's Lode, cerargyrite ! proustite, pyrargyrite ! -native
silver, gold, pyromorphite, quartz, malachite, stephanite ; polybasite ;
on Jordan Creek, stream tin ; Rising Star mine, stephanite, argentitet
pyrargyrite ; Charity mine, Warren's, scheelite, gold.
MONTANA.
Many mines of gold, etc., west of the Missouri River. HIGHLAND
DISTRICT. — Tetradymite. SILVER STAR DIST. — Psittacinite.
In the Yellowstone Park, in Montana and Wyoming Territories.—
Geyserite, amethyst! chalcedony, quartz crystals, quartz on calcite,
etc.
CATALOGUE OF AMERICAN LOCALITIES OF MINERALS.
%
COLORADO.
The principal gold mines of Colorado are in Boulder, Gil pin, Clear
Creek, and Jefferson Counties, on a line of country a few miles W. of
Denver, extending from Long's Peak to Pike's Peak. A large portion
of the gold is associated with veins of pyrite and chalcopyrite ; silver
and lead mines are at and near Georgetown, Clear Creek County, and
to the westward in Summit County, on Snake and Swan rivers.
At the GEORGETOWN mines are found : — native silver, pyrargyrite,
argentite, tetrahedrite, pyromorphite, galenite, sphalerite, azurite,
aragonite, barite, fluorite, mica.
TRAIL CREEK. — Garnet, epidote, hornblende, chlorite ; at the Free-
land Lode, tetrahedrite, tennantite, anglesite, caledonite, cerussite,
tenorite, siderite, azurite, minium ; at the Champion Lode, tenorite,
azurite, chrysocolla, malachite ; at the Gold Belt Lode, vivianite ; at
the Kelly Lode, tenorite ; at the Coyote Lode, malachite, cyano-
trichite.
Near BLACK HAWK.— At Willis Gulch, enargite, fluorite, pyrite ; at
the Gilpin County Lode, cerargyrite ; on Gregory Hill, feldspar ;
North Clear Creek, lievrite. — Galenite !
BEAR CREEK. — Fluorite, beryl ; near the Malachite Lode, malachite,
cuprite, vesuvianite, topazolite ; Liberty Lode, chalcocite.
SNAKE RIVER. —Penn District, embolite ; at several lodes, pyrar-
gyrite, native silver, azurite.
RUSSELL DISTRICT. — Delaware Lode, cMlcopyrite, crystallized gal-
enite.— Epidote, pyrite.
VIRGINIA CANON. — Epidote, fluorite ; at the Crystal Lode, native
silver, spinel.
SUGAR LOAF DISTRICT. —Chalcocite, pyrrhotite, garnet (mangane-
sian).
CENTRAL CITY. — Garnet, tenorite ; at Leavitt Lode, molybdenite ;
on Gunnell Hill, magnetite ; at the Pleasantview mine, cerussite.
GOLDEN CITY. — Aragonite ; on Table Mountain, leucite in amygda-
loid.
BERGEN'S RANCHE. — Garnet, actinolite, calcite.
BOULDER Co. — Red Cloud Mine : Native tellurium, altaite, hessite
(petzite), sylvanite, calaverite, schirmerite. Keystone Mine : Colora-
doite, magnolite, ferotellurite, tellurite, roscoelite ? also part of these
at Smuggler mine and Mountain Lion mine. Grand View mine : syl-
vanite, etc.
LAKE CITY, at the Hotchkiss Lode. — Petzite, calaverite (?), etc.
LAKE Co., Golden Queen mine. — Scheelite, gold.
PIKE'S PEAK, on Elk Creek. — Amazon-stone! ! smoky quartz! aven-
turine feldspar, amethyst, albite, fluorite, hematite, anhydrite (rare),
columbite.
SAN JUAN DISTRICT. — Gold, sphalerite, pyrite, galenite, chalcocite,
covellite, chalcopyrite.
CANADA EAST.
ABERCROMBIE. — Labrador! te.
AUBERT. — Gold, iridosmine, platinum.
BAIE ST. PA.Tji*.~-Menaccanite f apatite, allanite, rutile.
370 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
BOLTON. — Chromite, magnesite, serpentine, picrolite, steatite, bitter
spar, wad, rutile.
BOUCHEBVILLE. — Auyite in trap.
BROME. — Magnetite, chal copy rite, spJiene, menaccanite, phyllite,
sodalite, cancrinite, galenite, chloritoid, rutile.
BROUGHTON. — Serpentine, steatite.
CHAMBLY. — Analcite, cliabazite and calcite in trachyte, menaccanite.
CHATEAU RICHER. — Labrador -ite, hypersthene, andesite.
DAILLEBOUT. — Blue spinel with clintonite.
GRENVILLE. — Wollastonite, sphene, muscotite, vesuvianite, calcite,
pyroxene, serpentine, steatite (rensselaerite), chondrodite, garnet (cin-
namon-stone), zircon, graphite, scapolite.
FITZROY. — G raphite.
HAM. — Chromite in serpentine, diallage, antimony! senarmontite !
kermesite, valentinite, stibnite.
HUNTERSTOWN. — Scapolite, sphene, vesuvianite, garnet, brown tour-
maline !
INVERNESS. — Bornite, chalcocite, pyrite.
LAKE ST. FRANCIS. — Andalusite in mica slate.
LEEDS. — Dolomite, chalcopyrite, gold, chloritoid, chalcocite, bornite,
pyrite, steatite.
MILLE ISLES. — Labradorite! menaccanite, hypersthene, andesite,
zircon.
MONTREAL. — Calcite, augite, sphene in trap, chrysolite, natrolite,
dawsonite.
MORIN. — Sphene, apatite, labradorite.
ORFORD. — White garnet, chrome garnet, mitterite, serpentine.
OTTAWA. — Pyroxene. •
PORTAGE DE FORT. — Rensselaerite.
POTTON. — Chromite, steatite, serpentine, amiantlius.
ROUGEMONT. — Augite in trap.
ST. ARMAND.— Micaceous iron ore with quartz, epidote.
ST. FRANCOIS BEAUCE. — Gold, platinum, iridosmine, menaccaiiite,
magnetite, serpentine, chromite, soapstone, barite.
ST. JEROME. — Sphene, apatite, chondrodite, phlogopite, tourmalinet
zircon, garnet, molybdenite, pyrrhotite, wollastonite, labradorite.
ST. NORBERT.— Amethyst in greenstone.
SHERBROOK.— At Suffield mine, albite! native silver, argentite,
chalcopyrite, blende.
SOUTH-CROSBY. — Chondrodite.
STUKELEY. — Serpentine, verd-antique ! schiller spar.
SUTTON. — Magnetite, in fine crystals, hematite, rutilet dolomite,
magnesite, chromiferous talc, bitter spar, steatite.
UPTON. — Chalcopyrite, malachite, calcite.
VAUDREUIL. — Limonite, vivianite.
YAMASKA. — Sphene in trap.
CANADA WEST.
ARNPRIOR. — Calcite.
BALSAM LAKE. — Molybdenite, scapolite, quartz, pyroxene, pyrite.
BATHURST. — Barite, black tourmaline, perthite (orthoclase), peristerite
(albite), bytoumite, pyroxene, wilsonite, scapolite, apatite, titanite.
CATALOGUE OP AMERICAN LOCALITIES OF MINERALS. 371
BRANTFORD. — Sulphuric acid spring (4 '2 parts of pure sulphuric
acid in 1,000).
BROCK VILLE. — Pyrite.
BROME. — Magnetite.
BRUCE MINES on Lake Huron. — Calcitc, dolomite, quartz, chalcopy
rite, chalcocite.
BURGESS. — Pyroxene, albite, mica, corundum, sphene, chalcopyrite,
apatite, black spinel ! spodumene (in a boulder), serpentine, biotite.
BYTOWN. — Calcite, lytomiite, chondrodite, spinel.
CAPE IPPERWASH, Lake Huron. — Oxalite in shales.
CHAUDIERE VALLEY. — Gold, sphalerite, pyrite, pyrrhotite, galenite.
CLARENDON. — Vesuvianite, tourmaline.
DALHOUSIE. — Hornblende, dolomite.
DRUMMOND. — Labradorite.
ELIZABETHTOWN.— Pyrrhotite, pyrite, calcite, magnetite, talc, phlo-
gopite, sidcrite, apatite, cacoxenite.
ELMSLEY. — Pyroxene, sphene, feldspar, tourmaline, apatite, biotite,
zircon, red spinel, chondrodite.
FITZROY. — Amber, brown tourmaline, in quartz.
GOETINEAU RIVER, Blasdell's Mills.— Calcite, apatite, tourmaline,
hornblende, pyroxene.
GRAND CALUMET ISLAND. — Apatite plilogopite! pyroxene! horn-
blende, sphene, vcsuvianite ! ! serpentine, tremolite, scapolite, brown
and black tourmaline! pyrite, loganite.
HIGH FALLS OF THE MADAWASKA. — Pyroxene ! hornblende.
HULL. — Magnetite, garnet, graphite.
HUNTINGTON. — Calcite !
INNISKILLEN. — Petroleum.
KINGSTON. — Celestite.
LAC DES CHATS, Island Portage.— Brmcn tourmaline! pyrite, cal-
cite, quartz.
LANARK. — Raphilite (hornblende), serpentine, asbestus, perthite
(aventurine feldspar), peristerite.
LANSDOWNE. — Barite ! vein 27 in. wide, and fine crystals, rens.
selaerite, sphalerite, wilsonite, labradorite.
MADOC.— Magnetite.
MARMORA. — Magnetite, chalcolite, serpentine, garnet, epsomite,
specular iron, steatite.
McNAB.— Hematite, barite.
MICHIPICOTON ISLAND, Lake Superior. — Domeykite, nicolite, gen-
thite, chalcopy rite, native copper, native silver, chalcocite, galenite,
amethyst, calcite, stilbite, analcite. At Maimanse Bay: Coracite,
chalcocite, clialcopyrite, native copper.
N E WBOROUGH. —Ghon drodite, graphite.
P AKENH AM. — Hornblende.
PERTH. — Apatite in large beds, phlogopite.
ST. ADELE. — Chondrodite in limestone.
ST. IGNACE ISLAND. — Calcite, native copper.
SILVER ID., Lake Superior.— Argentite, native silver, galenite, nic-
colite, chalcocite, malachite.
SYDENHAM.— Celestite.
TERRACE COVE, Lake Superior. — Molybdenite.
WALLACE MINE, Lake Hurpn. — Hematite, nickel ore, nickel vitriol,
tfiakopyrite.
372 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
NEW BRUNSWICK.
ALBEBT Co. — Hopewell, gypsum ; Albert mines, coal (albertite) ;
Shepody Mountain, alunite in clay, calcite, pyrite, manganite, psilo-
melane, pyrolusite.
CARLETON Co. — Woodstock, chalcopyrite, hematite, limonite,
wad.
CHARLOTTE Co. — Campobello, at Welchpool, blende, chalcopyrite,
bornite, galenite. pyrite ; at head of Harbor de Lute, galenite ; Deer
Island, on west side, calcite, magnetite, quartz crystals ; Digdighash
River on west side of entrance, calcite ! (in conglomerate), chalcedony ;
at Rolling Dam, graphite ; Grandmanan, between Northern Head and
Dark Harbor, agate, amethyst, apophyllite, calcite, hematite, heulan-
dite, jasper, magnetite, natrolite, stilbite ; at Whale Cove, calcite!
heulandite, laumontite, stilbite, semi-opal !; Wagaguadavic River, at
entrance, azurite, chalcopyrite in veins, malachite.
GLOUCESTER Co. — Tete-a-Gouche River, eight miles from Bathurst,
chalcopyrite (mined), oxide of manganese ! ! formerly mined.
KINGS Co.— Sussex, near Gloat's mills, on road to Belleisle, argen-
tiferous galenite ; one mile north of Baxter's Inn, specular iron in
crystals, limonite ; on Capt. McCready's farm, selenite ! !
RESTIGOUCHE Co. — Belledune Point, calcite! serpentine, verd-an-
tique; Dalhousie, agate, carnelian.
ST. JOHN Co. — Black River, on coast, calcite, chlorite, chalcopyrite,
hematite ! Brandy Brook, epidote, hornblende, quartz crystals ; Carle-
ton, near Falls, calcite ; Chance Harbor, calcite in quartz veins, chlo-
rite in argillaceous and talcose slate ; Little Dipper Harbor, on west
side, in greenstone, amethyst, barite, quartz crystals ; Moosepath,
feldspar, hornblende, muscovite, black tourmaline ; Musquash, on
east side harbor, copperas, graphite, pyrite ; at Shannon's, chrysolite,
serpentine ; east side of Musquash, quartz crystals ! ; Portland at the
Falls, graphite ; at Fort Howe Hill, calcite, graphite ; Crow's Nest,
asbestus, chrysolite, magnetite, serpentine, steatite ; Lily Lake, white
augite ? chrysolite, graphite, serpentine, steatite talc ; How's Road,
two miles out, epidote (in syenite), steatite in limestone, tremolite ;
Drury's Cove, graphite, pyrite, pyrallolite? indurated talc ; Quaco, at
Lighthouse Point, large bed oxide of manganese ; Sheldon's Point,
actinolite, asbestus, calcite, epidote, malachite, specular iron ; Cape
Spenser, asbestus, calcite, chlorite, specular iron (in crystals) ; West-
beach, at east end on Evans's Farm, chlorite, talc, quartz crystals;
half a mile west, chlorite, chalcopyrite, magnesite (vein), magnetite ;
Point Wolf and Salmon River, asbestus, chlorite, chrysocolla, chalco-
pyrite, bornite, pyrite.
VICTORIA Co. — Tabique River, agate, carnelian, jasper; at mouth,
south side, galenite ; at mouth of Wapskanegan, gypsum, salt spring;
three miles above, stalactites (abundant) ; Quisabis River, blue phos-
phate of iron, in clay.
WESTMORELAND Co.— Bellevue, pyrite ; Dorchester, on Taylor's
Farm, cannel coal ; clay ironstone ; on Ayres's Farm, asphaltum, petro-
leum spring ; Grandlance, apatite, selenite (in large crystals) ; Mem-
ram cook, coal (albertite) ; Shediac, four miles up Scadoue River, coal.
YORK Co. — Near Fredericton, stibnite, jamesonite, berthierite ;
Pokiock River, stibnite, tin pyrites? in granite (rare).
CATALOGUE OP AMERICAN LOCALITIES OP MINERALS. 373
NOVA SCOTIA.
ANNAPOLIS Co. — Chute's Cove, apophyllite, natrolite ; Gates's Moun-
tain, anal cite, magnetite, mesolile ! natrolite, stilbite; Martial's Cove,
analcite / chabazite, heulandite ; Moose River, beds of magnetite ;
Nictau River, at the Falls, bed of hematite ; Paradise River, black
tourmaline, smoky quartz !! ; Port George, faroelite, laumontite, me-
solite, stilbite ; east of Port George, on coast, apophyllite containing
gyrolite ; Peter's Point, west side of Stonock's Brook, apophyllite !
calcite, heulandite, laumontite ! (abundant), native copper, stilbite ; St.
Croix's Cove, chabazite, heulandite.
COLCHESTER Co.— Five Islands, East River, 'barite! calcite, dolo-
mite (ankerite), hematite, chalcopyrite ; Indian Point, malachite,
magnetite, red copper, tetrahedrite ; Pinnacle Islands, analcite, calcite,
chabazite ! natrolite, siliceous sinter ; Londonderry, on branch of Great
Village River, barite, ankerite, hematite, Hmonite, magnetite ; Cook's
Brook, ankerite, hematite ; Martin's Brook, hematite, limonite ; at
Folly River, below Falls, ankerite, pyrite ; on high land, east of river,
ankerite, hematite, limonite ; on Archibald's land, ankerite, barite^
hematite ; Salmon River, south branch of, chalcopyrite, hematite ;
Shubenacadie River, anhydrite, calcite, barite, hematite, oxide of
manganese ; at the Canal, pyrite ; Stewiacke River, barite (in lime-
stone).
CUMBERLAND Co.— Cape Chiegnecto, barite ; Cape d'Or, analcite,
apophyllite!! chabazite, faro'elite, laumontite, mesolite, malachite,
natrolite, native copper, obsidian, red copper (rare), vivianite (rare) ;
Horse Shoe Cove, east side of Cape d'Or, analcite, calcite, stilbite ;
Isle Haute, south side, analcite, apophyllite !! calcite, heulandite !!
natrolite, mesolite, stilbite ! ; Joggins, coal, hematite, limonite ; mala-
chite and tetrahedrite at Seaman's Brook ; Partridge Island, analcite,
apophyllite! (rare\ amethyst! agate, apatite (rare), calcite!! chabazite
(acadialite), chalcedony, cat's eye (rare), gypsum, hematite, heulan-
dite ! magnetite, stilbite !! ; Swan's Creek, west side, near the Point,
calcite, gypsum, heulandite, pyrite ; east side, at Wasson's Bluff and
vicinity, analcite!! apophyllite! (rare\ calcite, chabazite!! (acadialite),
gypsum, heulandite !! natrolite ! siliceous sinter ; Two Islands, moss
agate, analcite, calcite, chabazite, heulandite; McKay's Head, anal-
cite, calcite, heulandite, siliceous sinter!
DIGBY Co. — Briar Island, native copper, in trap ; Digby Neck,
Sandy Cove and vicinity, agate, amethyst, calcite, chabazite, hsmatite !
laumontite ( abundant \ magnetite, stilbite, quartz crystals ; Gulliver's
Hole, magnetite, stilbite! ; Mink Cove, amethyst, chabazite! quartz
crystals; Nichols Mountain, south side, amethyst, magnetite!; Wil-
liams Brook, near source, chabazite (green), heulandite, stilbite, quartz
crystal.
GUYSBORO' Co. — Cape Canseau, andalusite.
HALIFAX Co. — Gay's River, galenite in limestone ; southwest of
Halifax, garnet, staurolite, tourmaline ; Tangier, gold! in quartz
veins in clay slate, associated with auriferous pyrite, galenite, hema-
tite, arsenopyrite, and magnetite ; gold at Country Harbor, Fort Clar-
ence, Isaac's Harbor. Indian Harbor, Laidlow's Farm, Lawrencetown,
Sherbrooke, Salmon River, Wine Cove, and other places.
HANTS Co.— Cheverie, oxide of manganese (in limestone) ; Petite
3?4 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
River, gypsum, oxide of manganese ; Windsor, calcite, cryptomorpL »
(baronatiocalcite), howlite, glauber salt. The last three minerals are
found in beds of gypsum.
KINGS Co. — Black Rock, centrallassite, cerinite ; cyanolite ; a few
miles east of Black Rock, prehnite ? stilbite ! ; Cape Blomidon, on the
coast between the cape and Cape Split, the following minerals occur
in many places (some of the best localities are nearly opposite Cape
Sharp) : anakite !! agate, amethyst ! apophyttite ! calcite, chalcedony,
chabazite, gmelinite (lederite), hematite, heulandite! laumontite, mag-
netite, malachite, mesolite, native copper (rare), natrolite f psilomelane,
stilbite! thomsonite, faroelite, quartz; North Mountains, amethyst,
bloodstone (rare), ferruginous quartz, mesolite (in soil) ; Long Point,
five miles west of Black Rock, heulandite, laumontite!! stilbite!!;
Mordeu, apophyttite, mordenite ; Scott's Bay, agate, amethyst, chalce-
dony, mesolite, natrolite ; Woodworth's Cove, a f Av miles west of
Scott's Bay, agate ! chalcedony ! jasper.
LUNENBERG Co. — Chester, Gold River, gold in quartz, pyrite, mis-
pickel ; Cape la Have, pyrite ; The " Ovens," gold, pyrite, arseno-
pyrite ; Petite River, gold in slate.
PICTOU Co. — Pictou, jet, oxide of manganese, limonite ; at Roder*s
Hill, six miles west of Pictou, barite ; on Carribou River, gray copper
and malachite in lignite ; at Albion mines, coal, limonite ; East River,
limonite.
QUEEN'S Co. — Westfield. gold in quartz, pyrite, arsenopyrite ; Five
Rivers, near Big Fall gold in quartz, pyrite, arsenopyrite, limonite.
RICHMOND Co. — West of Plaister Cove, barite and calcite in sand-
stone ; nearer the Cove, calcite, fluorite (blue), sideiite.
SHELBURNE Co. — Shelburne near mouth of harbor, garnets (in
gneiss) ; near the town, rose quartz ; at Jordan and Sable River, stau-
rolite (abundant), schiller spar.
SYDNEY Co. — Hills east of Lochaber Lake, pyrite, chalcopyrite, side-
rite, hematite ; Moiristown, epidote in trap, gypsum.
YARMOUTH Co. — Cream Pot, above Cranberry Hill, gold in quartz,
pyrite ; Cat Rock, Fouchu Point, asbestus, calcite.
NEWFOUNDLAND.
ANTONY'S ISLAND.— Pyrite.
CATALINA HARBOR. — On the shore, pyrite !
CHALKY HILL. — Feldspar.
COPPER ISLAND, one of the Wadham group. — Chalcopyrite.
CONCEPTION BAY. — On the shore south of Brigus, bornite and gray
copper in trap.
BAY OF ISLANDS. — Southern shore, pyrite in slate.
LAWN. — Galenite, cerargyrite, proustite, argentite.
PLACENTIA BAY. — At La Manche. two miles eastward of Little
Southern Harbor, galenite ! ; on the opposite side of the isthmus from
Placentia Bay, barite in a large vein, occasionally accompanied by
chalcopyrite.
SHOAL BAY. — South of St. John's, chalcopyrite.
TRINITY BAY. — Western extremity, barite.
HARBOR GREAT ST. LAWRENCE.— West side, fluorite, galenite.
FOREIGN MINING REGIONS. 375
BRITISH COLUMBIA.
CARIBOO DISTRICT. — Native gold, galena.
ON FRAZER RIVER. — Gold, argentiferous tetrahedrite, cerargyrite,
cinnabar.
OMINICA DISTRICT. — Native gold, argentiferous galenite, native
silver, silver-amalgam.
HOWE'S SOUND. — Bornite, molybdenite, mica.
TEXADA ID. — Magnetite.
II. BRIEF NOTICE OF FOREIGN MINING
REGIONS.
THE geographical positions of the different mining regions are learned
with difficulty from the scattered notices in the course of a minera-
logical treatise. A general review of the more important is therefore
here given, to be used in connection with a good map.
A course across Europe, from southeast to northwest, passes over a
large part of the mining regions, and it will be found most convenient
to the memory to mention them in this order, commencing with the
borders of Turkey.
1. The mines of the Bannat in Southern Hungary, near the borders
of Turkey (about latitude 45°), situated principally at Orawitza, Sasz-
ka, Dognaszka, and Moldawa : argentiferous copper ores, chalcocite,
malachite, copper pyrites, cuprite, galenite, ores of zinc, cobalt, native
gold ; yielding silver, gold, copper, and lead ; rock : syenyte, and gran-
ular limestone.
2. The mines of Western Transylvania, about latitude 46°, situated
between the rivers Maros and Aranyos, at Nagyag, Offenbanya, Sa-
lathna, and Vorospatak : native gold, telluric gold, telluric silver,
white tellurium, with galenite, blende, orpiment, realgar, stibnite, tet-
rahedrite, rhodochrosite or carbonate of manganese, manganblende ;
especially valuable in gold and silver.
3. In the mountain range, bounding Transylvania on the north,
about latitude 47° 40', at Nagybanya, Felsobanya, and Kapnik : na-
tive gold, red silver, argentiferous tetrahedrite, chalcopyrite or pyri-
tous copper, blende, realgar, stibnite or gray antimony ; rock : por-
phyry.
4. In the Konigsberg Mountains, Northern Hungary, about latitude
48° 45', at Schemnitz and Kremnitz : argentiferous galenite, and chal-
copyrite, native gold, red silver ore, stibnite, some cobalt ores and bis-
muth, arsenopyrite or mispickel ; particularly valuable for gold, sil-
ver and antimony ; rock : diorite and porphyry.
5. To the east of the Konigsberg Mountains, at Schmolnitz and Retz-
banya : chalcopyrite, tetrahedrite, blende, stibnite ; particularly valu-
able for copper ; rock : clay slate.
6. Illyria, west of Hungary, at Bleiberg and Raibel (in Carinthia) :
argentiferous galenite, calamine, with some chalcopyrite and other
ores, affording silver and zinc abundantly ; rock : mountain limestone.
— Also at Idria, native mercury and cinnabar, in argillaceous schist,
376 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
7. In Western Styria, at Schladming : arsenical nickel, copper
nickel, native arsenic, arsenical iron, largely worked for nickel ; rock :
argillaceous slate. Illyria and Styria are noted also for their iron ores,
especially siderite or spathic iron.
8. In the Tyrol, at Zell : argentiferous copper and iron ores, aurife-
rous pyrite, native gold ; rock : argillaceous slate.
9. In the Erzgebirge separating Bohemia from Saxony, and consist-
ing principally of gneiss :
A. Bohemian or southern slope, at Joachimsthal, Mies, Schlacken-
wald, Zinnwald, Bleistadt, Przibram, Katherinenberg : tin ores, ar-
gentiferous galenite (worked principally for silver), arsenical cobalt
ores, copper nickel ; affording tin, silver, cobalt, nickel and arsenic.
B. Saxon or northern slope, at Altenberg, Geyer, Marienberg, Anna-
berg, Schneeberg, Ehrenfriedersdorf, Johanngeorgenstadt, Freiberg :
argentiferous galenite (worked only for silver), tin ore, various cobalt
and nickel ores, vitreous and pyritous copper ; affording silver, tin,
cobalt, nickel, bismuth, and copper.
10. In Silesia, in the'Riesengebirge. an eastern extension of the Erz-
gebirge, at Kupferberg, Jauer, Reichenstein : ores of copper, cobalt,
affording copper, cobalt, arsenic and sulphur.
11. In Silesia, in the low country east of the Riesengebirge, near
the boundary of Poland, at Tarnowitz : calamine, smithsonite, blende,
argentiferous galenite ; affording zinc, silver and lead ; rock : moun-
tain limestone.
12. Northwest of Saxony, near latitude 51° 30', at Eisleben, Gerlstadt.
Sangerhausen, and Mansfeld : tetrahedrite, somewhat argentiferous,
bornite or variegated copper ore, affording copper ; rock : a marly bi-
tuminous schist (kupferschiefer) more recent than the Carboniferous
strata.
13. In the Harzgebirge (Hartz Mountains), north of west from Eis-
leben, about latitude 51° 50', at Clausthal, Zellerfeld, Lauthenthal,
Wildemann, Grund, Andreasberg, Goslar, Lauterberg : chalcocite or
vitreous copper, tetrahedrite, chalcopyrite, cobalt ores, copper nickel,
ruby silver ore, argentiferous galenite. blende, antimony ores ; afford-
ing silver, lead, copper, and some gold.
14. In Hesse-Cassel, to the southwest of the Hartz, at Riechelsdorf :
arsenical cobalt, arsenical nickel, nickel ochre, native bismuth, bis-
muthinite, galenite, affording cobalt ; rock : red sandstone. Also at
Bieber, cobalt ores in mica slate.
15. In the Bavarian or Upper Rhine (Palatinate), near latitude 49°
45', at Landsberg near Moschel, Wolf stein, and Mprsfeld : cinnabar,
native mercury, amalgam, horn quicksilver, pyrite, some tetrahedrite,
and chalcopyrite ; rocks : coal formation.
16. Province of the Lower Rhine, at Altenberg, near Aix la Chapelle
(or Aachen) : calamine, smithsonite, galenite, affording zinc ; rock :
limestone. The same just south in Netherlands, at Limburg, and also
to the west at Vedrin, near Namur.
17. There are also copper mines at Saalfeld, west of Saxony, in
Saxon-Meiningen, in Southern Westphalia near Siegen, in Nassau at
Dillenberg, and elsewhere.
18. In Switzerland, at Canton du Valais : argentiferous galenite, and
valuable nickel and cobalt ores.
19. The range of the Vosges parallel with the Rhine, about St.
FOREIGN MINING REGIONS. 377
Marie aux-Mines : argentiferous galenite (affording 1-1000 of silver),
with pyromorphites, tetrahedrite, antimonial sulphuret of silver, na-
tive silver, arsenical cobalt, native arsenic, and pyrite, occasionally
auriferous ; affording silver and lead ; rocks : argillaceous schist, sye-
nyte, and porphyry.
20. In France there are also the mining districts of the Alps, Au-
vergne or the Plateau of Central France, Brittany, and the Pyrenees,
but none are very productive, except in iron ores. Brittany resembles
Cornwall, and formerly yielded some tin and copper. The valley of
Oisans in the Alps, at Allemont, contains argentiferous galenite, arseni-
cal cobalt and nickel, gray copper, native mercury, and other ores, in
talcose, micaceous and syenytic schists, but they are not now explored.
The region of Central France is worked at this time only at Pont-
Gibaud, in the department of Puy-de-Dome, and at Vialas and Ville-
fort in the Gard. The former is a region of schistose and granite
rocks, intersected by porphyry, affording some copper, antimony, lead,
and silver ; the latter of gneiss, affording lead and silver, from argen-
tiferous galena. The French Pyrenees are worked at the present time
only for iron.
21. In England there are two great metalliferous districts :
A. On the southwest, in Cornwall, and the adjoining county of De-
vonshire : pyritous copper and various other copper ores, tin ores,
galenite, with some bismuth, cobalt, nickel and antimony ores ; afford-
ing principally copper, tin, and lead ; rocks : granite, gneiss, micaceous
and argillaceous schist, elvanyte.
B. On the north, in Cumberland, the adjoining parts of Durham,
with Yorkshiie and Derbyshire, just south : galenite, and other lead
ores, blende, copper ores, calamine and smithsonite (the zinc ores es-
pecially at Alstonmoor in Cumberland, and Castleton and Matlock, in
Derbyshire), affording some zinc, and three-fifths of the lead of Great
Britain, and some copper ; rock: Carboniferous limestone.
C. There is also a vein of calamine, blende, and galenite, in the
same limestone at Holywell, in Flintshire, on the north of Wales ;
another of calamine at Mendip Hills, in Southern England, south of
the Bristol Channel, in Somersetshire, occurring in magnesian lime-
stone ; mines of copper on the Isle of Anglesey, in North Wales, in
Westmoreland and the adjacent parts of Cumberland and Lancashire,
in the southwest of Scotland, the Isle of Man, and at Ecton in Stafford-
shire, &c.
22. In Spain there are mines —
A. On the south, in the mountains near the Mediterranean coast,
in New Grenada, and east to Carthagena, in Murcia ; also in New
Grenada, in the Sierra Nevada, or the mountains of Alpujarras, the
Sierra Almagrera, the Sierra de Gador, just back of Almeria, and at
Almazarron near Carthagena : galenite, which is argentiferous at the
Sierra Almagrera and at Almazarron, affording full 1 per cent, of
silver ; rock : limestone, associated with schist and crystalline rocks.
B. The vicinity of the range of mountains running westward from
Alcaraz (to the district of La Mancha), to Portugal. 1. On the south,
near the centre of the province of Jaen, at Linares, latitude 38° 5',
longitude 3° 40': galenite, cerussite, cuprite, malachite, in granite and
schists ; affording lead and copper. 2. In La Mancha, at Alcaraz,
northeast of Linares, latitude 38° 45' : calamine affording abundantly
378 SUPPLEMENT TO DESCRIPTIONS OF SPECIES.
zinc. 3. In the west extremity of La Mancha, near latitude 88° 38',
at Almaden : cinnabar, native mercury, pyrite, in clay slate. 4. South-
west of Almaden, in Southern Estremadura, and Northwestern Seville :
tetrahedrite ; at Guadalcanal, Cazalla, Rio Tinto : chalcanthite or cop-
per vitriol, malachite, with some red silver ore, and native silver, in
schists or limestones.
There are also mines of lead and copper at Falsete in Catalonia ; in
Galicia, a little tin ore ; in the Asturias at Cabrales, copper ores.
23. In Sweden : - 1. At Fahlun, in Dalecarlia : chalcopyrite, bornite ;
rock, syenyte and schists. At Finbo and Broddbo : tantalum ores, tin
ore. At Sala : argentiferous galeuite, affording lead and silver ; rock,
crystalline limestone. At Vena (or Wehna) and at Tunaberg : arseni-
cal cobalt, erythrite ; rock, mica slate and gneiss. At Dannemora and
elsewhere : magnetic iron ore or magnetite.
24. In Norway, at Kongsberg : argentite or vitreous silver, native
silver, horn silver, native gold, galenite, native arsenic, blende ; rock,
mica slate. At Modum and Skutterud : cobalt ores, native silver ;
rock, mica slate. At Arendal, magnetic iron ore.
25. In Russia: — In the Urals (mostly on the Asiatic side), at
Ekatherinenberg, Beresof, Nischne Tagilsk, etc. : native gold, plati-
num, iridium, native copper, cuprite, malachite. 2. The Altai
(Southern Siberia), at Kolyvan and Zmeof : native gold, native silver,
argentiferous galena, cerussite, native copper, oxides of copper, mala-
chite, chalcopyrite; rocks, metamorphic ^eds and porphyry. 3. In the
Daouria Mountains, east of Lake Baikal, at Nertchinsk : argentifer-
ous galenite, cerussite, mimetite, gray antimony, arsenopyrite, cala-
mine, cinnabar ; rocks, compact limestone and schists.
26. In Australia :— In Southern Queensland, and the northern part
of New South Wales, or the New England district : tin ore or cassi-
terite abundant, with also native gold. In New South Wales, along
the Blue Mountains and the continuation of the range parallel with
the coast north and south, in the Bathurst, Mudgee, Lachlan and other
districts : native gold, chalcopyrite, some cinnabar. In Victoria : na-
tive gold. In South Australia, especially at the Burra, Wallaroo, and
Moonta mines : copper ores.
Other foreign mining regions are the copper mines of Cuba, and
South America ; the silver mines of Chili, Bolivia, Peru in South
America, and of Mexico ; the gold mines of South America, especially
those of Brazil, South Africa, and of the Philippines, Borneo, New
Guinea, New Caledonia, and New Zealand in Australasia ; the quick-
silver mines of Huanca Velica, Peru, and those of China ; the tin
mines of Malacca (principally on the island of Junk-Ceylon), and of
the island of Banco between Borneo and Sumatra ; of zinc, in China ;
of platinum, in Brazil, Colombia, St. Domingo, and Borneo ; of palla-
dium, in Brazil ; of arsenic in Khoordistan, Turkey in Asia, and also in
China ; of nickel, in New Caledonia.
DETERMINATION OP MINERALS. 379
IV. DETERMINATION OF MINERALS.
Itf the determination of minerals, no one order in the
succession in which characters should be examined answers
for all minerals, or even for all of the same section of species.
A. For species having a metallic lustre :
Color will be first noted ; and then streak — that is, the
color of the mineral on a surface scratched or abraded by a
fine file, or when very finely powdered, and the lustre of the
powder or abraded surface, whether metallic like the min-
eral or unmetallic. Hardness should be ascertained when
obtaining the streak.
Bloivpipe and chemical characters are of the highest value,
giving generally the most certain results.
Specific gravity is especially distinctive with species hav-
ing a metallic lustre, since the differences in density among
such species are usually large.*
Crystalline form and cleavage are of first importance,
whenever the specimen allows of their determination.
B. For species without metallic lustre :
Streak is sometimes of importance, especially among spe-
cies in which it is highly colored.
Color is generally of little value owing to the variations
that frequently come in through impurities.
Lustre is one of the first characters the eye will observe,
but its variation under most species is wide, and often it
is of little value. State of aggregation and fracture for the
most part serve to distinguish only varieties.
Hardness is^lso often a varying character, the range
under some species being from 1 to 6 in the scale of hard-
ness ; and still its indications are generally important.
Crystalline form and cleavage are always important when
observable.
* In using the spiral balance of Jolly (page 65), the spiral spring is put at any de-
sired height by means of the sliding rod C. The stand B is raised so that the lower
pan, rf, shall be in the water, while the other, c, is above it. The position of the in-
dex, or signal, m, is then noted, by sighting across it and observing that the index
and the image of it in the mirror are m the same horizontal line ; let *> stand for it.
Next put the fragment of the mineral in c, and drop the si and B until the lower pan
hange free in the water, and note the position of 7/1, which we may represent by t ;
t-s will equal the weight in the air. Now place the fragment in the lower pan. and
after adjusting again the stand B, the position of m is noted as before ; call it u.
Then t—u = loss of weight in water. From these values the specific gravity is at one*
obtained.
380 DETERMINATION OP MINERALS.
Taste is of limited value, as few minerals are sufficiently
soluble ; but among soluble minerals it is easily observed,
and often decisive.
Action of acids, cold or hot, in trials as to effervescence,
solubility, gelatinizing or not, and in making solutions for
examination with other reagents, is a very important means
of distinguishing species.
Blowpipe reactions are easily obtained, and of the high-
est value.
Specific gravity is an important reliance.
Refraction and polarization afford valuable criteria for
distinguishing species, and in a few cases no other means
are so reliable short of chemical analysis.
The following hints may be of service to the beginner in
the science, by enabling him to overcome a difficulty in the
outset, arising from the various forms and appearance of the
minerals quartz and limestone. Quartz occurs of nearly
every color, and of various degrees of glassy lustre to a dull
stone without the slightest glistening. The common gray-
ish cobble-stones of the fields are usually quartz, and others
are dull red and brown ; from these there are gradual transi-
tions to the pellucid quartz crystal that looks like the best
of glass. Sandstones and freestones are often wholly quartz,
and the seashore sands are mostly of the same material. It
is therefore probable that this "mineral will be often en-
countered in mineralogical rambles. Let the first trial ot
specimens obtained be made with a file, or the point of a
knife, or some other means of trying the hardness ; if the
file makes no impression, there is reason to suspect the
mineral to be quartz ; and if on breaking it, no regular
structure or cleavage plane is observed, but it breaks in all
directions with a similar surface and a more or less vitreous
lustre, the probability is much strengthened that this con-
clusion is correct. The blowpipe may next be used ; and
if there is no fusion produced by it in a careful trial there
can be little doubt that the specimen is in fact quartz.
Calcite (calcium carbonate), including limestone, is an-
other very common species. If the mineral collected is
rather easily impressible with a file, it may be of this spe-
cies ; if it effervesces freely when placed in a test-tube con-
taining dilute hydrochloric acid, and is finally dissolved, the
probability of its being carbonate of lime is increased ; if
DETERMINATION OF MINERALS. 381
the blowpipe produces no trace of fusion, but a brilliant
light from the fragment before it, but little doubt remains
on this point. Crystalline fragments of calcite break with
three equal oblique cleavages.
Familiarized with these two Protean minerals by the
trials here alluded to, the student has already surmounted
the principal difficulties in the way of future progress.
Frequently the young beginner, who has devoted some
time to collecting all the different colored stones in his
neighborhood, on presenting them for names to some prac-
tised mineralogist, is a little disappointed to learn that,
with two or three exceptions, his large variety includes
nothing but limestone and quartz. He is perhaps gratified,
however, at being told that he may call this specimen yel-
low jasper, that red jasper, another flint, and another horn-
stone, others chert, granular quartz, ferruginous quartz,
chalcedony, prase, smoky quartz, greasy quartz, milky
quartz, agate, plasma, hyaline quartz, quartz crystal, basa-
nite, radiated quartz, tabular quartz, etc., etc.; and it is
often the case, in this state of his knowledge, that he is
best pleased with some treatise on the science in which
all these various stones are treated with as much promi-
nence as if actually distinct species ; being loth to receive
the unwelcome truth, that his whole extensive cabinet con-
tains only one mineral. But the mineralogical student has
already made good progress when this truth is freely ad-
mitted, and quartz and limestone, in all their varieties,
have become known to him.
The student should be familiar with the use of the blow-
pipe and the reactions, as explained on pages 82 and 85 ;
and it would be still better if a fuller treatise on the subject
had been carefully studied. He should be supplied with the
three acids in glass-stoppered bottles ; a fourth bottle con-
taining hydrochloric acid diluted one-half with water, for
obtaining effervescence with carbonates ; test tubes ; and
also the ordinary blowpipe apparatus and tests, including
platinum wire, platinum forceps, glass tube, " cobalt solu-
tion," litmus and turmeric paper, etc.
Also the following :
A small file, three-cornered or flat, for testing hardness.
A knife with a pointed blade of good steel, for trying
hardness. It may be magnetized, to be used as a magnet,
though a good horseshoe magnet of small size is better.
382 DETERMINATION OF MINERALS.
The series of crystallized minerals, constituting the seals
of hardness (see page 63). Diamond and talc are least es-
sential.
Cutting pliers, for removing chips of a mineral for blow-
pipe or chemical assay.
A pocket- lens.
A hammer weighing about two pounds, resembling a
stone-cutter's hammer, having a
flat face, and at the opposite
end an edge having the same
direction as the handle. The
handle should be made of the
best hickory, and the mortise to
receive it should be as large as the handle. A foot scale
should be marked on the handle of the hammer, divided
into inches, the smallest divisions needed. It will be often
of use in getting out a yard-stick, or a ten-foot pole, for
large measurements. A similar hammer, having the upper
part prolonged to a blunt point, to be used like a pick, is
often convenient.
A hammer of half a pound weight, like the figure, to be
used in trimming specimens.
A small jeweler's hammer, for trying the malleability of
globules obtained by the blowpipe, and for other purposes,
and a small piece of steel for an anvil.
Two steel chisels, one six inches long, and the other three.
When it is desired to pry open seams in rocks with the
larger chisel, two pieces of steel plate should be provided to
place on opposite sides of the chisel, after an opening is ob-
tained ; this protects the chisel and diminishes friction
while driving it.
For blasting, if this is desired :
Three hand-drills 18, 24, and 36 inches long, an inch in
diameter. The best form is a square bar of steel, with a
diagonal edge at one end. The three are designed to follow
one another.
A sledge-hammer of six or eight pounds weight, to use
in driving the drill.
A sledge-hammer of ten or twelve pounds weight, for
breaking up the blasted rock.
A round iron spoon, at the end of a wire fifteen or eigh-
teen inches long, for removing the pulverized rock from the
drill-hole.
DETERMINATION OP MINERALS. 383
A crowbar, a pickaxe, and a hoe, for removing stones and
earth before or after blasting.
Cartridges of blasting powder, to use in wet holes. They
should one-third fill the drill-hole. After the charge is put
in, the hole should be filled with sand and gravel alone with-
out ramming. If any ramming material is used, plaster of
Paris is the best, which has been wet and afterwards scraped
to a powder.
Patent fuse for slow match, to be inserted in the car-
tridge, and to lead out of the drill-hole.
The table beyond is prepared especially to aid in instruc-
tion, and comprises, with few exceptions, only the species
that are described in large type through the work, exclusive
of the hydrocarbon compounds. The following abbrevia-
tions are used in it, in addition to those explained on page
90. With reference to colors : bnh, brownish ; bkh, black-
ish ; gnh, greenish ; gyh, grayish ; rdh, reddish. The acids :
nit., nitric acid ; sulph. acid, sulphuric acid ; HCL, hydro-
cloric acid ; sulph., sulphurous or sulphurous acid.
Keactions : gelatinizing with acid, see page 81 ; reaction
for sulphur with soda, see page 89 ; blue or red color with
cobalt solution, see page 88 ; hydrous, yielding water in a
closed tube ; anhydrous, not yielding water in a closed tube,
or only traces, see page 86 ; B.B. lithium-red color, see
page 87 ; B.B. yreen flame due to boron, see page 87 ; coal is
used for charcoal ; fus. for fusible ; in/us, for infusible ;
sol. for soluble ; st. for streak.
In using the blowpipe it is important to remember that
a trial of fusibility with the forceps, if not at once pro-
ducing fusion, should be made on a piece of the mineral not
larger than the fourth of an ordinary pin-head, andit'should
be either oblong and slender, or thin, and be made to pro-
ject considerably beyond the points of the forceps, lest
the forceps carry off the heat, and cause a failure where
there ought to be success. Further, it should be in mind,
that in using charcoal, a white coating is always a conse-
quence of burning it, since the ash from its own combustion
is white. Again, before testing for sulphur by means of
soda and a polished surface of silver, it is necessary to try
the flame and the soda for sulphur. Gas-flame always con-
tains traces of sulphur, and sometimes too much for safe
conclusions in this trial.
384 DETERMINATION OF MINERALS.
A mineralogist sometimes has occasion to measure dis-
tances, and by the following method he may make himself
quite an accurate odometer :
Let him first find, or make, along a roadside, a measured
distance of 800 to 1,000 feet, and then walk it at his ordi-
nary walking pace three or four times, and note the number
of steps. He will thus ascertain the actual length of his
pace, and also find that in his ordinary walk it does not
diifer much from thirty inches ; it may be an inch or two
less, or one, two, or three more than this. Now four times
thirty inches is ten feet. If then, as he walks, he counts
one for every fourth step, each unit in the count will stand
for ten feet nearly, and 100, for 1,000 feet nearly. If his
pace is thirty-one inches, let him add a unit for every
thirty in the counting, or, which is the same thing, call his
thirty thirty-one, and the needed correction will be made;
or if his step is twenty-nine and one-half inches, subtract
one from every sixty in the counting, or in other words du-
plicate the sixty. Or the correction may be made at the
end of the pacing ; if at 600, this number, after adding
a thirtieth, becomes 620 ; and the distance would hence be
6,200 feet. With a little practice the counting may be
carried on almost unconsciously, and when the thoughts
are elsewhere ; that is, unless there is a talking friend by
one's side.
An instrument, called a pedometer ', of the shape and size
of a small watch, is to be had of instrument makers, which,
if carried in the waistcoat pocket, will do the registering for
the pedestrian and note the distance, without any attention
on his part. But the odometer explained above, when once
in working order, is always at hand.
SYNOPSIS OF THE ARRANGEMENT.
I. ELEMENTS.
1. Lustre metallic ; liquid.
2. Lustre metallic ; malleable and eminently sectile.
3. Lustre metallic ; brittle ; B.B. on coal, wholly volatile, with no
sulphurous fumes.
4. Lustre metallic ; brittle ; H.=l-2 ; leaves a trace on paper ; B.B.
on coal, infusible, no fames or odor.
5. Unmetallic ; burns readily with a blue flame.
6. Lustre adamantine ; H. = 10.
DETERMINATION OF MINERALS. 385
II. MINERALS NOT ELEMENTS, THAT B.B. ON
COAL ARE WHOLLY VOLATILE.
1. Lustre metallic ; streak metallic.
2. Lustre unmetallic ; streak same as color.
III. COMPOUNDS, OF GOLD, SILVER, COPPER,
LEAD, TIN, MERCURY, CHROMIUM, COBALT,
MANGANESE : yielding, on heating, a malleable, or
liquid (for mercury ores), metallic globule, as explained
on pages 389-393, or else affording a decisive blowpipe
reaction, proving the presence of one or more of these
metals.
A. Yielding a malleable globule B. B. on coal with, if not
without, soda.
1. Compounds of Gold.
2. Compounds of Silver.
3. Compounds of Copper.
4. Compounds of Lead.
5. Compounds of Tin.
B. Yielding drops of mercury with soda in a closed tube.
1. Compounds of Mercury.
C. A decisive reaction with borax or salt of phosphorus
for chromium, cobalt, or manganese.
1. Compounds of Chromium.
2. Compounds of Cobalt.
3. Compounds of Manganese.
IV. MINERALS OF METALLIC OR SUBMETALLIC
LUSTRE, NOT INCLUDED IN PRECEDING
DIVISIONS.
1. Yielding fumes in the open tube or on coal, but not
wholly vaporizable.
386 DETERMINATION OF MINERALS.
A. Streak metallic.
B. Streak unmetallic.
a. Fumes sulphurous only.
b. Fumes arsenical, with or without sulphurous.
2. Not yielding fumes of any kind ; streak unmetallic.
A. B.B. easily fusible, giving a magnetic bead ; lustre sub
metallic.
B. Infusible, or nearly so.
a. Reaction for iron ; anhydrous.
b. Reaction for iron ; hydrous.
c. Reaction for chromium or titanium,
d. Reaction for osmium with nitre.
V. MINERALS OF UNMETALLIC LUSTEE.
1. Having an acid, alkaline, alum-like, or styptic taste.
A. CARBONATES : Taste alkaline ; effervescing with HC1.
B. SULPHATES : No effervescence ; reaction for sulphur
with soda. »
C. NITRATES : With sulph. acid, reddish acrid fumes ;
no action with HC1 ; deflagrate.
D. CHLORIDES : With sulph. acid, acrid fumes of HC1 ;
no fumes with HC1.
E. BORATES : No effervescence ; reaction for boron when
moistened with sulph acid.
2. Not haying either of the above-mentioned kinds of
taste.
A. CARBONATES : Effervescing with HC1.
a. Infusible ; assay alkaline after ignition.
b. Infusible ; become magnetic and not alkaline, on
ignition.
c. Infusible ; B.B. on coal with soda, zinc oxide
vapors.
d. Infusible ; B.B. on coal reaction for nickel.
e. Fusible ; assay alkaline after ignition.
B. SULPHATES : Reaction for sulphur with soda,
a. Fusible ; assay alkaline after fusion.
b. Fusible ; reaction for iron.
c. Infusible.
DETERMINATION OP MINERALS. 387
C. ARSENATES : on coal arsenical fumes.
D. SILICATES, PHOSPHATES, OXIDES :
Species not included in the preceding subdivisions.
X. STREAK DEEP RED, YELLOW, BROWNISH-YELLOW, GREEN, OB
BLACK.
A. Infusible, or fusible with difficulty.
B. Fusible without much difficulty.
H. STREAK GRAYISH OR NOT COLORED.
1. Infusible.
A. Gelatinize with acid, forming a stiff jelly.
B. Not forming a stiff jelly ; hydrous.
a. Blue color with cobalt solution.
6. Reddish or pink color with cobalt solution.
c. Not blue or red with cobalt solution.
C. Not forming a stiff jelly ; anhydrous.
a. Blue color with cobalt solution.
b. Not blue or reddish color with cobalt solution.
2. Fusible with more or less difficulty.
A. Gelatinize and form a stiff jelly.
a. Hydrous ; fuse easily.
b. Hydrous ; fuse with much difficulty.
c. Anhydrous.
a. No reaction for sulphur ; no coating on coal.
ft. Reaction for sulphur with soda.
B. Not gelatinizing.
1. Structure eminently micaceous ; folia tough, pearly,
and H. of surface of folia not over 3*5 ; anhydrous
or hydrous.
2. Structure not eminently micaceous.
a. Hydrous.
a. No reaction for phosphorus, or boron.
|. H. =1 to 3 ; lustre not at all vitreous.
ff. H.=3-5-6'5; lustre of cleavage sur-
face sometimes pearly ; elsewhere vi-
treous.
ft. Reaction for phosphorus or boron.
b. Anhydrous.
a. B.B. lithium-red flame.
ft. B.B. boron reaction (green flame).
y. B.B. reaction for titanium.
8. B. B. reaction for fluorine or phosphorus.
e. B.B. reaction for iron.
£. B.B. no reaction for iron : not of the pre-
ceding subdivisions.
388 DETERMINATION OP MINERALS.
I. ELEMENTS.
1. Lustre metallic ; liquid.
MERCURY, p. 128. This is the only metallic mineral which is liquid
at the ordinary temperature and atmospheric pressure.
2. Lustre metallic ; malleable and eminently sectile.
GOLD, p. 109. G. =15-19-5 ; yellow ; fusible ; not sol. in nitric acid
or HC1, but sol. in aqua regia.
PLATINUM, p. 124. G.= 16-19 ; nearly white ; infusible ; insol. in
nitric acid.
PALLADIUM, p. 127. G.=ll-8-ll-8 ; grayish-white ; diff. fusible ;
sol. in nitric acid.
SILVER, p. 116. G. =10-11-1 ; white ; fusible ; sol. in nitric acid,
and deposited again on copper.
COPPER, p. 131. G.=r8'84; copper-red; fus.; sol. in nitric acid,
and the solution becomes sky-blue when ammonia is added
IRON, p. 171. G.— 7-3-7-8; iron-gray; attracted by the magnet.
The only other mineral of metallic lustre that is also malleable and
eminently sectile is argentite, a silver sulphide, along with two others
of like composition but different crystallization.
3. Lustre metallic ; brittle ; B.B. wholly volatile,
but give off no sulphurous fumes.
BISMUTH, p. 101. G.=9 73 ; reddish- white ; on coal a yellow coat-
ing ; fumes inod.
ANTIMONY, p. 100. G. =6'6-6'7; tin-white ; fumes dense wh., inod.
ARSENIC, p. 98. G.=r5'9-6 ; tin-white ; fumes white, alliaceous.
TELLURIUM, p. 96. G.=6'l-6'3 ; tin- white ; fus.; fumes white ;
flame green.
The only other mineral that is wholly volatile, and also gives off no
sulphurous fumes, is allemontite, an antimony arsenide.
4. Lustre metallic ; H. =1-2 ; B.B. on coal infusible ;
no fumes.
GRAPHITE, p. 107.
5. Lustre unmetallic ; takes fire readily in the flame
of a candle, and burns with a blue flame.
SULPHUR, p. 94.
6. Lustre adamantine ; EL =10.
DIAMOND, p. 103. Easily scratches corundum or sapphire.
DETERMINATION OP MINERALS. 389
II. MINEKALS, NOT ELEMENTS, THAT
ARE WHOLLY VOLATILE B.B.
ON COAL.
1. Lustre metallic ; streak metallic.
TETRADYMITE, p. 102. G.— 7 2-7 '9 ; pale steel-gray; so soft as
to soil paper ; on coal white fumes ; flame bluish-green; sometimes
sulph. odor ; in open tube, a coating which fuses to white drops.
BISMUTHINITE, p. 102. G.^6'4-7'2; whitish lead-gray; on coal
yellow coating and sulph. odor.
STEBNITE, p. 100. G. =4-5-4 52 ; lead-gray; on coal dense wh.
fumes and wh. coating .
2. Lustre unmetallic ; streak same nearly as color.
ORPIMENT, p. 99. Lemon yellow ; on coal burns, odor alliaceous.
REALGAR, p. 99. Bright red ; on coal burns, odor alliaceous.
ARSENOLITE, p. 99. White ; on coal, odor alliaceous.
VALENTINITE, p. 101. White ; on coal dense wh. fumes, inott.
CINNABAR, p. 128. Red ; in open tube, sulph. odor, coating of
mercury globules.
SALMIAK, p. 230. White ; saline and pungent taste ; on coal, fumes
of ammonia.
III. COMPOUNDS OF GOLD, SILVER, MER-
CURY, COPPER, LEAD, TIN, CHRO-
MIUM, COBALT, MANGANESE.
A. Yielding a malleable globule B.B. on coal, with
or without soda
1. COMPOUNDS OF GOLD.
Yield gold, or an alloy of gold and silver, B.B. on coal. The TELLTJ-
KIUM ORES, pp. 115, 116, give a coating of drops of tellurous acid in
open tube.
2. COMPOUNDS OP SILVER.
B.B. easily fusible ; G. above 5 ; yield, with few exceptions, a glo-
bule of silver (white and malleable), on coal, with soda, if not without ;
and, in the exceptions, silver globule obtained by cupellation. All
have metallic lustre excepting cerargyrite, bromyrite, and iodyrite.
390 DETERMINATION OF MINERALS.
a. EMINENTLY SECTILE.
ARGENTTTE, p. 117. G.=7'2-7'4; lustre metallic ; on coal sulph.
fumes.
CERARGYRITE, p. 120. G. =5 '3-5 "6; lustre like that of white,
gray, or greenish to brownish wax.
&. NOT SECTILE ; ON COAL ODOROUS FUMES.
SULPHIDES, p. 118. Gives sulph. odor.
ARSENICAL ORES, pp. 119, 120. Alliaceous fumes.
SELENIDES, p. 118. Horse-radish odor.
C. NOT SECTILE ; ON COAL FUMES OF ANTIMONY OR TELLURIUM.
ANTIMONIAL ORES, pp. 119, 120. Dense white fumes of anti-
mony; with also, if sulphur is present, sulph. fumes. •
TELLURIDES, p. 118. In open tube coating which fuses to drops
of tellurous acid.
STROMEYERITE, p. 119. Contains copper, and requires cupellation
in order to obtain a globule of silver.
3. COMPOUNDS OF COPPER.
Unless iron is present, a globule of metallic copper is obtained with
soda, if not without, on coal; with a nitric acid solution and ammonia
in excess a bright blue color; moistened with HC1 the blue flame of
chloride of copper; and a clean surface of iron in the nitric solu-
tion becomes coated with copper.
1. METALLIC LUSTRE.
SULPHIDES, pp. 132-136. On coal or in open tube sulph. fumes.
ARSENIDES, SELENIDES, p. 135.
ANTIMONIAL SULPHIDES, p. 135, 136.
2. LUSTRE UNMET AL]£c ; B.B. NEITHER ON COAL NOR IN OPEN
TUBE ANY ODOROUS FUMES ; NO TASTE.
CUPRITE, p. 136. H. =3'5-4; G.=5'8-6'2; isometric; deep red, streak
bnh-red.
ATACAMITE, p. 136. Darkish bright green, streak gnh; B.B. on
coal fuses, coloring O.P. azure-blue, with a green edge ; easily sol.
in acids.
PHOSPHATES, p. 139.
MALACHITE, p. 140. H.=3-4; G.=3'7-4; light to deep green; ef~
fervesces with HC1.
AZURITE, p. 141. H. =3 5-4-5; G.=3 5-3'9; deep blue ; effervesces
with HC1.
DIOPTASE, p. 141. H.=5; G. =3 25-3 35; emerald-green; B.B. in-
fusible.
CHRYSOCOLLA, p. 142. Bluish-green; B.B. infusible.
DETERMINATION OF MINERALS. 391
3. LUSTRE T7NMETALLIC; B.B. ON COAL, OR IN CLOSED TUBE, ODOROUS
FUMES OF ARSENIC OR SULPHUR, OR REACTION FOR SULPHUR.
ARSENATES, p. 189. On coal arsenical fumes.
CHALCANTHITEj p. 137. Blue; taste nauseous; astringent.
Also Stromeyerite, Stannite, Bournonite give reactions for copper.
4. COMPOUNDS OF LEAD.
Yield B.B. on coal a dark lemon-yellow coating ; finally, with soda,
if not without, a globule (metallic and malleable) of lead is ob-
tained ; but by continued blowing with O.F. the lead all goes off in
fumes, leaving other more stable metals (silver, etc.) behind. Sul-
phurous, selenious and tellurous fumes easily obtained either on
coal or in an open tube from the sulphide, selenide, tellurides ; and
arsenical or antimonial fumes from ores containing arsenic or anti-
mony. None have taste.
1. LUSTRE METALLIC.
GALENITE, p. 145. H. =2*5 ; O. =7*2-7 "7 ; cleavage cubic eminent ;
lead-gray, streak same ; in open tube sulph.
SELENIDES, TELLURIDES, ANTIMONIAL and ARSEN-
ICAL SULPHIDES, page 149.
2. LUSTRE UNMET ALLIC ; NO ODOROUS FUMES, OR REACTION FOR
SULPHUR.
MINIUM, p. 149. Bright red, streak same.
CROCOITE, p. 150. Monoclinic ; bright red, streak orange-yellow ;
B.B. with salt of phosphorus emerald-green bead.
PYROMORPHITE, p. 151. Hexagonal ; bright green to brown,
rarely orange-yellow ; streak white. B.B. fuses easily, coloring
flame bluish-green.
CERUSSITE, p. 152. Trimetric, often in twins; H.=3-3'5;
G.=6'4-68; white, gyh ; lustre adamantine; often tarnished to
grayish metallic adamantine. Effervesces in dilute nitric acid.
3. UNMETALLIC ; REACTION FOR SULPHUR.
ANGLE SITE, page 150. Trimetric ; white, gyh ; fuses in flame of
candle ; B.B. reaction for sulphur ; no effervescence with acids.
5. COMPOUNDS OF TIN.
CASSITERITE, p. 160. H.=6-7 ; G. =6 '4-7-1 ; brown, gyh, ywh,
black; B.B. infusible; on coal with soda a globule of tin, yield
no fumes.
Stannite, p. 158. A copper, iron, and tin sulphide, does not give
B.B. a metallic malleable globule.
392 DETERMINATION OP MINERALS.
B. Yield drops of mercury in closed tube with or
without soda.
COMPOUNDS OP MERCURY.
CINNABAR, p. 128. H.=2-2 5 ; G.=8-9 ; bright red, bnh red, gyh ;
streak scarlet.
AMALGAM, p. 117. H. =3-3-5 ; G. = 13-14 ; silver-white; yields
silver B.B. on coal.
Spaniolite, p. 136, a variety of tetrahedrite, yields mercury.
C. No malleable globule ; decisive reaction with borax
or salt of phosphorus for chromium, cobalt, or
manganese.
1. COMPOUNDS OF CHROMIUM.
Give with borax an emerald-green bead in both flames.
CHROMITE, p. 180. H.=5'5 ; G.=4'3-4'5; isometric, often m
octahedrons, massive ; submetallic ; bnh iron-black, streak brown ;
B.B. on coal becomes magnetic ; with borax, a bead which is
emerald-green on cooling.
CROCOITE, p. 150. H.-25-3; O.=5'9-6'l; bright red, streak
orange ; B.B. fuses very easily, on coal globule of lead, and with
salt of phosphorus emerald-green bead. PhcBnicochroite and Vauque-
Unite are other lead chromates.
2. COMPOUNDS OF COBALT.
Give a blue color with borax after, if not before, roasting.
[When much nickel or iron is present the blue color is not ob-
tained ; and species or varieties of this kind are not here included.]
1. LUSTRE METALLIC.
COBALTTTE, p. 165. H.— 55; G.=6-6'3; isometric and pyrito-
hedral ; rdh silver- white, streak grayish -black ; B.B. on coal sulph.
and arsen. fumes, and a magnetic globule.
SMALTITE, p. 1G5. H.=5'5-6; G.rr6'4-7'2; tin-white, streak
gyh black ; B.B. on coal alliaceous fumes ; most varieties fail to give
the blue color immediately with borax, because of the iron and
nickel present.
LINNJEITE, p. 164. H.=5'5; G.=4'8-5; isometric; pale steel-
gray, copper-red tarnish, streak bkh gray. B.B. on coal sulph.
fumes.
2. LUSTRE UNMETALLIC.
ERYTHRITE, p. 167. H. = l 5-25 ; G.=295; monoclinic, one
highly perfect cleavage, also earthy ; rose-red, peach-blossom red,
streak reddish ; B.B. fuses easily ; yields water.
DETERMINATION OF MINERALS. 393
BIEBERITE, p. 168. A cobalt sulphate.
REMINGTONITB, p. 168. A hydrous cobalt carbonate.
.3. COMPOUNDS OF MANGANESE.
Give an amethystine globule in O.F. with borax. [The globule
looks black if too much of the manganese mineral is used, and with
a large excess may be opaque.]
1. GIVES OFF CARBONIC ACID WHEN TREATED WITH DILUTE H Cl ;
LUSTRE UNMETALLIC.
RHODOCHROSITE, p. 191. H.=35-4'5 ; G. =3 4^3 7 ; rose-red.
Also manganese-bearing varieties of calcite, dolomite, ankerite, side-
rite, all of which have the cleavage and general form of rhodochro-
site ; when containing a few per cent, of manganese they often turn
black on exposure.
2. TREATED WITH H Cl YIELDS CHLORINE FUMES.
MANGANITE, p. 189. H.=4; G.=4'2-4'4; in oblong trimetric
prisms ; grayish-black, streak reddish-brown ; lustre submetallic ;
B. B. infusible ; yields water.
PSILOMELANE, p. 189. H.=5-7 ; G. =3-7-4'7 ; amorphous ; black,
streak brownish-black ; submetallic ; B.B. infusible ; yields water.
Wad is similar, but often contains cobalt.
PYROLUSITE, p. 188. H.— 2-2 5 ; G.=4'82 ; in stoutish trimetric
crystals ; metallic ; dark steel-gray, streak black or bluish-black ;
B.B. infusible ; yields no water.
BRAUNITE and HAUSMANNITE (p. 189) are other anhydrous
manganese oxides.
FRANKLINITE, p. 179. H. =5-5-6 5; G.=5-5'l ; in octahedrons
and massive ; iron-black, streak dark reddish brown ; B.B. infusi-
ble ; but little chlorine with H Cl.
8. C02 OR Cl NOT GIVEN OFF WHEN TREATED WITH HC1;
AN HYDROUS.
RHODONITE, p. 247. H.=5'5-6'5; G. =3 4-3 68; rose-red; B.B.
fuses easily.
TRIPLITE, p. 191. H.=5-5; G.=3'4-3'8; brown to black; B.B.
fuses very easily, globule magnetic ; sol. in H Cl.
HELVITE, p. 256. H.=6-65; G. =3 1-3 3; in yellowish tetrahe-
hedrons ; B. B. fuses easily.
SPESSARTITE (Manganesian Garnet), p. 258. H. =6'5-7 ; G =3'7-
4*4 ; in dodecahedrons and trapezohedrons ; red, brownish-red ;
B.B. fuses easily.
TEPHROITE, p. 256. H.=5'5-6; G.=4-4'12; reddish to brown
and_gray ; B.B. fuses not very easily ; gelat. in H Cl.
Mite, p. 256, is related, and also gelatinizes.
394 DETERMINATION OF MINERALS.
HAUERITE, p. 188. H.=4; G.=3'46; isometric; reddish brown,
streak brownish-red. B.B. yields sulphur, after roasting reaction
for manganese.
ALABANDITE, p. 188. H. =3'5-4 ; G. =4 ; submetallic, iron-black;
streak green ; B.B. on coal sulphur, after roasting reaction for
manganese.
Vesuvianite, epidote, axinite, ilvaite, gothite, include varieties that
give reaction for manganese.
IV. MINERALS OF METALLIC OR SUB-
METALLIC LUSTRE NOT INCLUDED
IN PRECEDING DIVISIONS.
1. YIELDING FUMES IN THE OPEN TUBE
OR ON COAL, BUT NOT WHOLLY
VAPORIZABLE.
A. STREAK METALLIC.
MOLYBDENITE, p. 96. H.=l-l-5; G.=4'4-4'8 ; lead-gray, and
leaves trace on paper ; B.B. on coal sulphurous fumes
PISMUTHINITE, p. 102. H. =2 ; G.=6'4-7'2 ; lead gray, whitish ;
B.B. on coal sulphurous fumes, and yellow bismuth oxide ; sol. in
hot nitric acid and a white precip. on diluting with water
B. STREAK UNMETALLIC.
a. FUMES SULPHUROUS ONLY.
PYRITE, p. 172. H.— 6-6-5; G.=4'8-5'2: isometric and pyritohe-
dral ; pale brass-yellow, streak gnh black, bnh black ; B.B. on
coal, fuses to a magnetic globule.
MARCASITE, p. 174. H.=6-6'5; G.-4-68-485; trimetric ; pale
bronze-yellow ; streak gyh black, bnh black ; B.B. like pyrite.
PYRRHOTITE, p. 174. H.=3'5-4-5; G. =4 4-4 -68; hexagonal;
bronze-yellow, rdh ; streak gyh black; slightly magnetic; B.B.
fuses to a magnetic mass.
MILLERITE, p. 164. H.=3-3'5; G.=4'6-5'7, rhombohedral,
usually in acicular or capillary forms, also in fibrous crusts ; brass-
yellow, somewhat bronze-like ; B.B. fuses to a globule, reacts for
nickel.
LINNJEITE. p. 164. H.=5'5 : G.=4'8-5 ; isometric; pale steel-
gray, copper-red tarnish ; streak blackish -gray ; B.B. on coal fuses
DETERMINATION OF MINERALS. 395
to a magnetic globule, after roasting gives reactions for nickel,
cobalt, and iron.
SPHALERITE, p. 154. H.-35-4; G.=3'94'2; isometric; lustre
submetallic ; streak nearly uncolored ; nearly infusible alone and
with borax ; on coal a coating of zinc oxide.
b. ARSENICAL FUMES, WITH OR WITHOUT SULPHUROUS.
ARSENOPYRITE, p. 175. H.=5-6 ; G.=6-6'4 ; trimetric ; white,
gyb, streak dark gyh black. In closed tube, red arsenic sulphide
and metallic arsenic ; B.B. on coal fuses to magnetic globule.
GERSDORFFITE, p. 166. H.^5'5 ; G.=5'6-6'9 ; isometric, py-
ritohedral ; white, gyh, streak grayish -black. In closed tube
arsenic sulphide, on coal not magnetic, and reacts for nickel and
often cobalt.
NICCOLITE, p. 166. H.=5-5'5; G. =7 '3-7 -7,* hexagonal ; pale
copper-red, streak pale bnh black ; in open tube, coating of arsen-
ous acid ; B.B. on coal no sulph. fumes, fuses to globule which re-
acts for iron, cobalt and nickel.
SMALTITE, p. 165. H.=:5'5-6 ; G. =6-4-7 '2 ; isometric ; tin-white ;
streak gyh black ; on coal, no fumes of sulphur or only in traces.
2. NOT YIELDING FUMES OF ANY KIND.
STEEAK UNMETALLIC.
A. B.B. EASILY FUSIBLE, AND GIVING A MAGNETIC BEAD.
LUSTRE SUBMETALLIC.
ILVAITE, p. 263. H.=5'5-6; G.=3'7-4'2 ; trimetric; gyh iron-
black, streak gnh or bnh black ; gelat. with H Cl.
ALLANITE, p. 263. H. =5'5-6 ; G.=3 4 2 ; monoclinic ; bnh pitch-
black, streak gyh, bnh ; B.B. fuses easily ; most varieties gelat.
withHCl.
WOLFRAMITE, p, 183. H.=5-5'5; G.=7'l-7'6; monoclinic; gyh
black or bnh black ; B.B. fuses easily, and reacts for iron, manga-
nese, and tungsten.
B. INFUSIBLE OR NEARLY SO.
a. REACTION FOR IRON ; ANHYDROUS; H.=5-6'5.
MAGNETITE, p. 178. G.=4'9-5'2 ; isometric ; iron-black ; streak
black ; strongly magnetic.
MENACCANITE, p. 178. G. =4*5-5 ; rhombohedral ; iron-black :
streak submetallic, black to bnh red ; very slightly magnetic.
HEMATITE, p. 176. G.=4'5-5'3; rhombohedral ; gyh iron-black,
in very thin splinters or scales blood-red by transmitted light;
streak red ; sometimes slightly magnetic.
MARTITE, p. 177. Same as hematite, but isometric.
TANTALITE, p. 184. G.=7-8; trimetric; iron-black, streak rdh
brown to black.
396 DETERMINATION OF MINERALS.
FRANKLINITE, p. 179. H.=5'5-6'5; G.=4'8-5'l ; octahedral,
massive ; iron-black ; streak dark rdli brown ; slightly attracted
by magnet ; with soda reaction for manganese.
COLUMBITE, p. 183. G. =5' 4-6 5; trimetric ; iron-black, gyh
black, streak dark red to black, often with a bluish steel -tarnish.
SAMARSKITB, p. 202. H.=5'5-7; G.=5'6-58; velvet-black,
pitch-black ; streak dark rdh brown ; B.B. glows ; fuses with dif-
ficulty.
b. REACTION FOR IRON J HYDROUS ; LUSTRE SUBMETALLIC.
LIMONITE, p. 181. G. =3-6-4 ; massive, often stalactitic and tube-
rose with surface sometimes highly lustrous, often subfibrous in
structure ; black, bnh black ; streak bnh yellow.
GOTHITE, p. 182. G.=4'0-4-4; trimetric; also fibrous and mas-
sive ; bkh brown ; streak bnh yellow.
TURGITE, p. 182. G.-3-6-4'68 ; fibrous and massive, looking like
limonite ; black, rdh black, streak red ; in closed tube decrepitates,
which is not the case with gothite and limonite.
C. REACTION FOR CHROMIUM OR TITANIUM.
CHROMITE, p. 180. H.=5-5; G.=4'3-4'6; isometric; submetal-
lic ; bnh iron-black, streak brown ; B.B. with borax gives a bead
which on cooling is chrome-green.
RUTILE, p. 162. H. =6-65; G.=418-4-25 ; black, streak bnh;
reacts for titanium. Black varieties of brookite (p. 163), submetallic
in lustre, give same reaction.
Euxenite, p. 202 ; yttrotantalite, p. 202 ; cescliynite, p. 202 ; ferguson-
ite, p. 202, and perofskite, p. 163, are submetallic in lustre.
d. HEATED WITH NITRE IN A MATRASS YIELDS FUMES OF OSMIUM.
IRIDOSMINE, p. 127. H.=6-7; G. =19-21 -2 ; in small scales
from auriferous or platiniferous sands ; tin- white, gyh.
V. LUSTKE UNMETALLIC.
1. MINERALS HAYING AN ACID, ALKALINE,
ALUM-LIKE, OR STYPTIC TASTE.
A. CARBONATES : Taste alkaline ; effervescing with HC1.
NATRON, p. 229. Effloresces on exposure.
TRONA, p. 230. Does not effloresce.
DETERMINATION OF MINERALS. 397
B. SULPHATES : No effervescence; reaction B.B. on coal with soda
for sulphur.
MASCAGNITE, p. 231. Yields ammonia.
MIRABIL1TE, p. 226. Monoclinic, crystals stout ; taste cool,
saline, bitter ; B.B. flame deep yellow.
EPSOMITU, p. 205. Trhnetric, crystals ordinarily slender, spicule-
like ; taste bitter and saline ; B.B.' flame not yellow.
ALUNOGOEN, p. 197. Taste like common alum.
KALINITE, MENDOZ1TE and other alums, p. 198.
MELANTERITE, p. 182. Green ; taste styptic ; reacts for iron.
CHALCANTHITE, p. 137. Blue ; reacts for copper.
MORENOSITE, p. 168. Green ; reacts for nickel.
BIEBERITE, p. 168. Reddish ; reacts for cobalt.
GOSLARITE, p. 156. White ; reacts for zinc.
JOHANNITE, p. 171. Emerald-green, reacts for uranium.
C. NITRATES : With sulphuric acid, reddish acrid fumes ; no action
with hydrochloric acid ; deflagrate.
NITRE, p. 228. Not efflorescent. Strong deflagration.
SODA-NITRE, p. 229. Efflorescent.
NITROCALCITE, p. 214. Deflagration slight.
D. CHLORIDES : With sulphuric acid acrid fumes of HC1 ; no fumes
with HC1.
S ALMIAK, p. 230. Taste saline, pungent ; on coal, evaporates ; with
soda, odor of ammonia.
SYLVITE, p. 224. Taste saline ; B.B. flame purplish.
HALITE or COMMON SALT, p. 224. Taste saline ; B.B. flame
yellow.
E. BORATES. No effervescence with acids ; B. B. reaction for boron,
when moistened with sulphuric acid.
SASSOLITE, p. 97. Taste feebly acid ; B.B. very fusible.
BORAX, p. 227. Taste sweetish alkaline ; B.B. puffs up.
2. MINEKALS NOT HAYING AN ACID, ALKA-
LINE, ALUM-LIKE OR STYPTIC TASTE.
A. CARBONATES : Effervescing with HCL
A. INFUSIBLE ASSAY ALKALINE AFTER IGNITION.
p. 215. H. under .3 '5 ; G.=2'5-2'72; ft A R=W5° 5',
with three easy cleavages parallel to E; colors various ; effervesces
readily with cold HC1 ; anhydrous.
398 DETERMINATION OF MINERALS.
ARAGONITE, p. 218. H.=3'5-4; G.=2.94; trimetric, cleavage im-
perfect ; otherwise like calcite.
DOLOMITE, p. 219. H.=3'5-4 ; G.rr2'8-2'9 ; rliombohedral, Rf\R
=106 15' ; colors various ; effervesces but slightly with cold HC1,
unless finely pulverized ; anhydrous.
MAGNESITE, p. 207. H. =3 5-4'5 ; G. =3-3'l ; rhombohedral, # A ,R
=107° 29' ; white, ywh, gyh ; effervesces but slightly with cold
HC1 ; anhydrous.
HYDROMAGNESITE, p. 207. H.=l-3 5 ; G.r=2 14-218 ; hydrous.
B. INFUSIBLE ; BECOME MAGNETIC AND NOT ALKALINE AFTER
IGNITION.
SIDERITE, p. 185. H. =3 5-4 -5 ; G.=3'7-3'9 ; rhombohedral, R :R
=107° ; cleavage as in calcite ; becomes brown on exposure, chang-
ing to limonitf.
ANKERITE, p. 186. H.=3'5-4; G.=2'9-3'l; #AjR=106° 7' ; be-
comes brown on exposure.
Some kinds of calcite and dolomite contain iron enough to become
magnetic on ignition.
C. INFUSIBLE ; B.B. ON COAL WITH SODA, COATING OF ZINC OXIDE.
SMITHSONITE, p. 156. H.=5; G.=4-45; rhombohedral like
calcite; R/\R—\QT 40' ; crystals often an acute rhombohedron ;
anhydrous.
HYDROZINCITE, p. 157. H.=2-2'5; G.^3'6-3'8; white, gyh,
ywh, often earthy ; reacts for zinc ; hydrous.
D. INFUSIBLE ; B.B. ON COAL REACTION FOR NICKEL.
ZARATITE (Emerald nickel), p. 168. H.=3. Emerald green, streak
paler.
E. FUSIBLE ; ASSAY ALKALINE AFTER IGNITION.
WITHERITE, p. 221. H.=3-3'75 ; G. =4 29-4 "35 ; trimetric ; white,
ywh, gyh ; B.B. fuses easily, flame ywh green ; anhydrous.
STRONTIANITE, p. 223 H.=3'5-4 ; G. =3 6-3 '72 ; trimetric ; pale
green, gray, ywh, white ; B.B. fuses only on thin edges, flame
bright red ; anhydrous.
BARYTOCALCITE, p. 222. Monoclinic. G.=3'6 3 '66 ; B.B. nearly
like witherite.
Other carbonates are the Lead Carbonate, p. 152, and Copper Car-
bonates, p. 140, included severally under the heads of LEAD and COP-
PER, on page 391.
DETERMINATION OF MINERALS. 399
B. SULPHATES or SULPHIDES : Reaction for Sulphur
with Soda.
A. FUSIBLE ; ASSAY ALKALINE AFTER FUSION.
BARITE, p. 220. H.=2'5-3'5 ; G.=43 4'72 ; trimetric ; white, ywh,
gyh, bluish, brown; B.B. decrepitates and fuses ; flame yellow-
ish-green ; anhydrous.
CELESTITB, p. 222. H.=3-3'5; G.=3'9-3'98; trimetric; white,
pale blue, rdh ; B.B. fuses ; flame red ; anhydrous.
ANHYDRITE, p. 211. H.=3-35; G.=2D-30; trimetric, with
three rectangular and easy cleavages differing but slightly ; white,
bluish, gyh, rdh, red ; B.B. fuses, flame reddish -yellow.
GYPSUM, p. 210. H. =1-5-2; G.=2'3-235; monoclinic, one per-
feet, pearly cleavage ; white, gray, but also brown, black from im-
purities ; B.B. yields much water, becomes white and crumbles
easily.
B. FUSIBLE J REACTION FOR IRON.
COPIAPITE, p. 182. H.=15; G. =2 '14; yellow ; on coal, becomes
magnetic ; hydrous.
Hauynite, p. 270, also gives the sulphur reaction with soda.
C. INFUSIBLE, OR NEARLY SO.
ALUMINITE, p. 199. H.— 1-2 ; G. — 1'66 ; adheres to the tongue ;
white ; B.B. blue with cobalt solution. Alunite, p. 198, is similar,
but H.=4, and G. =2 "58-2 75.
SPHALERITE, p. 154. H.^3'5-4 ; G. =3 "9-4 '2 ; isometric ; light
to dark resin -yellow ; B. B. on coal, coating of zinc oxide.
G. AESENATE9 : Arsenical fumes on coal.
SOORODITE, p. 185. H.r=3'5 4 ; G. =3- 1-3 3 ; trimetric ; leek-green
to liver-brown ; B.B. fuses easily, flame blue, and with soda gives
a magnetic bead ; on coal alliaceous fumes ; in H Cl. sol.
PHARMACOSIDERITE, p. 185. H.=25; G.=:29-3; cubes and
tetrahedrons ; dark green, bnh, reddish ; B.B. same as for scoro-
dite.
PHARMACOLITE, p. 214. H.^2-2'5 ; G. =2 6-2 75 ; wh, gyh, rdh ;
monoclinic with one eminent cleavage ; B.B. fuses, flame blue ;
on coal, alliaceous fumes ; after ignition assay alkaline ; in HC1
sol.
400 DETERMINATION OF MINERALS.
D. SILICATES, PHOSPHATES, OXIDES : SPECIES NOT IN-
CLTJDED IN THE THREE PRECEDING SUBDIVISIONS.
I. Streak deep red, yellow, brownish-yellow, green or black.
A. INFUSIBLE, OR FUSIBLE WITH MUCH DIFFICULTY.
HEMATITE, p. 176. Red to black ; streak red ; B.B. reaction for
iron ; magnetic after ignition in R. F. ; anhydrous.
LIMONITE, p. 181. Brownish and ochre-yellow to black ; streak
brownish -yellow ; B.B. gives off water, turns red, becomes mag-
netic in R.F.
TURGITE, p. 182. Brown to black ; streak red ; B.B. gives off
water ; decrepitates ; becomes magnetic in R.F.
FERGUSONITE, p. 202. Brownish black ; infusible.
ZINCITE, p. 155. Red ; streak orange ; B.B. on coal, zinc oxide
coating, and coating moistened with cobalt solution, green in R.F.
B. FUSIBLE WITHOUT MUCH DIFFICULTY.
WOLFRAMITE, p. 183. Grayish to brownish black ; streak dark
reddish brown to black; lustre submetallic ; G. —1- 1-7 55. B.B.
fuses easily, and becomes magnetic ; reaction for tungsten.
VIVIANITB, p. 184. Blue to green (to white) ; streak bluish-
white ; G. =2-5-2 '7 ; H. =15-2, hydrous ; B.B. fuses easily to mag-
netic globule, coloring flame bluish-green.
TORBERNITE, p. 170. Bright green, square tabular micaceous
crystals ; streak paler green ; H.=2-2'5 ; hydrous ; yields a globule
of copper with soda.
SAMARSKITE, p. 202. H.=5"5-6; G.=56-58; velvet-black;
streak dark reddish brown ; B.B. fuses on the edges.
II. Streak grayish or not colored.
1. INFUSIBLE.
A. GELATINIZE WITH ACID, FORMING A STIFF JELLY.
CHRYSOLITE, p. 255. Yellow-green to olive -green, looking like
glass; H.=67; G.=3'3-35; B.B. reacts for iron, becomes mag-
netic ; anhydrous.
CHONDRODITE, p. 281. H.=6-65; G. =3 '1-3 "25 ; pale yellow
to brown, and reddish -brown ; lustre vitreous to resinous ; B.B. re-
action for iron and fluorine ; anhydrous.
ALLOPHANE, p. 296. H.=3; G.=1'8-1'9 ; always amorphous,
never granular in texture; bluish, greenish ; B.B. infus., a blue
color with cobalt solution ; hydrous.
WiUemite, Calamine, Sepiolite, fuse with great difficulty, and are in-
cluded under fusible gelatinizing species, p. 402.
DETERMINATION OF MINERALS. 401
B. NOT FORMING A STIFF JELLY WITH ACID ; HYDROUS.
#. Blue with cobalt solution (owing to presence of aluminum).
WAVELLITE, p. 201. H.=3'25-4; G.=2'3-2-4; white to green,
brown ; B.B. bluish-green flame after moistening with sulph. acid.
LAZULITE, p. 199. H.=5'6; G.=3 3'1 ; blue; B.B. green flame,
especially after moistening with sulph. acid ; hydrous.
TURQUOIS, p. 200. H.=6 ; G. =2-0-285; sky-blue, pale green;
B.B. flame green.
KAOLINITE, p. 310. H.=l-2; G. =2 '4-2 65; white when pure;
feel greasy ; B.B. flame not green.
GIBBSITE, p. 194. H.=2'5-3'5 ; G.=2'3-2'4 ; white, grayish, green-
ish ; B.B. flame not green ; soluble in strong sulph. acid.
DIASPORE, p. 194. H. =6-5-7 ; G. =3'3-3'5 ; in thin foliated crys-
tals, plates or scales; white, greenish, brownish ; B.B. flame not
green ; soluble in sulphuric acid after ignition.
b. Pale red or pink color, with cobalt solution (owing to presence of
magnesium).
BRUCITE, p. 204. H.=2'5; G.=2'3-245 ; pearly, white, green-
ish ; foliaceous or fibrous and flexible ; B.B. after ignition, alkaline.
c. Not blue or red with cobalt solution.
OPAL, p. 239. H. =5-5-6-5; G.=l-9-2'3; B.B. with soda soluble
with effervescence.
GENTHITE, p. 309. H.=3-4; G.=2'4; pale green, yellowish;
B.B. with borax a violet bead, becoming gray in R.F. owing to
nickel ; decomp. by H Cl.
CHRYSOCOLLA, p. 142. H.=2-4 ; G.=2 2'24 ; pale bluish-green
to sky-blue ; B.B. flame emerald-green, and with soda on coal globule
of copper.
The micas, chlorites, chloritoid, and serpentine often fuse on their
edges with much difficulty.
C. NOT FORMING A STIFF JELLY ; ANHYDROUS. H.=5 to 9.
a. Blue color with cobalt solution.
CORUNDUM, p. 192. H.=9; G.=4; rhombohedral ; blue, white,
red, gray, brown.
CHRYSOBERYL, p. 196. H.=8'5 ; G.=3'7 ; gray, green, to eme-
rald-green.
TOPAZ, p. 286. H.=8; G.=3'5; in rhombic prisms with perfect
basal cleavage, rarely columnar ; white, wine-yellow, and other
shades.
RUBELLITE, p. 283. H.=7'5 ; G.=3 ; in prisms of 3, 6, or 9 sides ;
rose-red ; reaction for boron.
ANDALUSITE, p. 284. H.=7'5; G.=3'2; always in prismatic
crystals, often tesselated within, /A 7=93° ; grayish-white to brown.
FIBROLITE, p. 285. H.=6-7 ; G.=3'2 ; columnar or fibrous forms
and prismatic crystals with brilliant diag. cleavage.
402 DETERMINATION OF MINERALS.
CYANITE, p. 286. H.— 5-7 (greatest on extremities of crystals);
G. — 3'6 ; in long or short prismatic crystallizations, often bladed
prisms ; pale blue to white and gray.
LEUCITE, p. 271. H. =5'5-6 ; G. =2'5 ; white, gyh ; often in trapezo-
hedral crystals.
&. Not giving a blue or reddish color with cobalt solution ; H. =
8 to 5.
SPINEL, p. 194. H.=8 ; G. =3'5 4'1 ; in octahedrons of red, green-
ish, gray, black colors. Gahnite is similar, but with borax on coal,
gives reaction for zinc.
BERYL, p. 252. H.=7'5-8; G.=2'6-2'7; always in hexagonal
prisms ; pale bluish and yellowish green, to emerald-green, also
resin yellow and white, no distinct cleavage.
ZIRCON, p. 259. H.=7-5 ; G. =4-4*75 ; dimetric, and often in square
prisms ; lustre adamantine ; brown, gray.
STAUROLITE, p. 291. H.=7; G.=3'4-3'8; in prisms of 123°,
and often in cruciform twins ; no distinct cleavage ; brown, black,
gray.
QUARTZ, p. 233. H.=7; G.=2'6; often in hexagonal crystals
with pyramidal terminations ; of various shades of color. OPAL,
p. 239, is in part anhydrous.
MONAZITE, p. 203. H.=5-5'5; G.=4'9-5'3; in small brown im-
bedded monoclinic crystals, with perfect basal cleavage ; B.B. flame
bluish-green when moistened with sulph. acid.
RUTILE, p. 162. H.=6-65; G.=4'15-4'25 ; dimetric; reddish-
brown to brownish -red, green, black ; B.B. reaction for titanium.
BROOKITE and OCTAHEDRITE, p. 163, are similar, except in crystal-
line forms, and G. in brookite 4'0-4'2o, in octahedrite 3'8-3'95.
PEROFSKITE, p. 163. H.=5-5 ; G.^4-4'1; yellowish, brown,
black ; cubic and octahedral forms ; B.B. reaction for titanic acid.
ENSTATITE, p. 244. H.=5'5 ; G.=3'l-3'3 ; in prismatic and fibrous
forms with /A/=88D 16', also foliated ; whitish, grayish, brown.
Anthophyllite is similar, but /A 7=125% and it fuses on the edges
with great difficulty.
lolite, apatite, scheelite, eudase, fuse with much difficulty, and
euclase gives some water in closed tube when highly ignited.
2. FUSIBLE WITH LITTLE OR MUCH DIFFICULTY.
A. Gelatinize and afford a Stiff Jelly,
a. Hydrous ; fuse easily.
DATpLITE, p. 289. H.=5-5'5; G.=2'8-3; white, greenish, yel-
lowish ; crystals glassy, stout, sometimes massive and porcellanous,
never fibrous ; B.B. fuses easily, reaction for boron.
NATROLITE, p. 299. H.=5-5'5 ; G.=2'3-2 4 ; in slender rhombic
prisms, and divergent columnar ; white, y wh, rdh, red ; B.B. fuses
very easily.
SCOLECITE, p. 299. H.=5-5'5 ; G.=216-2'4; cryst. much like
DETERMINATION OF MINERALS. 403
natrolite, but twinned, with converging striae on i-i as in figure on
p. 299; B.B. sometimes curls up, fuses very easily.
GMELINITE, p. 301. H. =4'5 ; G. =2-22 ; in small and short hex-
agonal or rhombohedral cryst. ; B.B. fuses easily.
PHILIPPS1TE, p. 302. H.=4-4'5 ; G. =2 "2 ; in twinned crystals ;
B.B. fuses rather easily.
LAUMONTITE, p. 293. H.=3'5-4 ; G.=2'2-2'4 ; white, reddish;
crystals become white and crumbling on exposure to the air ; B.B.
fuses rather easily.
Pectolite (p. 293), and Analdte (p. 299), imperfectly gelatinize.
&. Hydrous j fuse with much difficulty.
CALAMINE, p. 157. H.=4'5-5 ; G.=3 15-319 ; white, greenish,
bluish ; orthorhombic in crystals ; B.B fus. with great difficulty, re-
action for zinc and none for iron ; hydrous.
SEPIOLITE, p. 306. White ; soft and almost clay-like, also fibrous ;
B.B. fuses with difficulty, with cobalt solution reddish ; hydrous.
PYROSCLERITE, p. 317. H.=3 ; G.=2'74; micaceous ; B.B. fuses
on thin edges.
c. Anhydrous.
a NO REACTION FOR SULPHUR ; NO COATING ON COAL.
NEPHELITE, p. 269. H.=5'5-6 ; G.=2'5-2"65 ; hexagonal prisms
and massive ; vitreous, with greasy lustre ; white, y wh, gyh brown,
rdh ; B.B. fuses rather easily.
WOLLASTONITE, p. 244. H =4'5-5 ; G. =2 "75-2 "9 ; white, gyh,
rdh, bnh ; B.B. fuses easily.
SODALITE, p. 270. H.=5'5-6; G.=2'13-2-4; white, blue, red-
dish ; in dodecahedrons and massive ; B.B. fuses not very easily.
WILLEMITE, p. 157. H.=5'5; G.=3'9-43; white to greenish,
reddish, brownish ; B.B. glows and fuses with difficulty ; reaction
for zinc and none for iron ; anhydrous.
ft. REACTION FOR SULPHUR B.B. WITH SODA.
HAUYNITE, p. 270. H.=5'5-6 ; G.=2'4-25 ; blue, greenish; iso-
metric, in dodecahedrons, octahedrons ; B.B. fuses with some diffi-
culty.
DANALITE, p. 256. H. =5 "5-6 ; G. =3-427 ; isometric ; flesh-red to
gray ; B.B. fuses rather easily, and gives reaction for manganese
and zinc.
B. Not Gelatinizing.
STRUCTURE EMINENTLY MICACEOUS, SURFACE OF FOLIA
MORE OR LESS PEARLY ; H. OF SURFACE OF FOLIA
NOT OVER 3'5; ANHYDROUS OR HYDROUS.
FSCOVITE, BIOTITE, PHLOGOPITE, LEPIDOLITE, LE.
PIDOMELANE : for distinctions see pp. 266-268. Anhydrous,
404 DETERMINATION OF MINERALS.
or affording very little water; B.B. fuse with difficulty on thin
edges, excepting lepidomelane which fuses rather more easily.
MAKGARODITE, DAMOURITE, p. 313. Much like common
mica, but more pearly and greasy to the feel, folia not elastic ; giv-
ing a little water in the closed tube ; color usually whitish.
PENNINITE, RIPIDOLITE, PROCHLORITE, p. 318. Usually
bright or deep green, blackish-green, reddish, rarely white ; folia
tough, inelastic; B.B. diff. fus., reaction for iron and yield much
water ; partially decomposed by acids.
VERMICULITE, JEFFERISITE,p. 317. Brown, yellowish-brown,
green ; exfoliate remarkably ; yield much water.
MARGARITE, p. 319. H.-8;5-4'5 (highest on edges); G.=2-99;
white, ywh, rdh ; folia somewhat brittle ; B.B. fuses on thin edges ;
yields a little water.
TALC, p. 304.
FYROPHYLLITE, p. 306. Similar to talc; but B.B. exfoliates
remarkably ; blue with cobalt solution.
FAHLUNITE, p. 314, has often a more or less distinct micaceous
structure.
Autunite, p. 170, has a mica-like basal cleavage ; but it occurs
in small square tables of a bright yellow color. Diallage, p. 246,
has a structure nearly micaceous. Serpentine is sometimes nearly
micaceous, but the folia are not easily separable and are brittle.
Chloritoid has a perfect basal cleavage, but folia very brittle, and
cleavage less easily obtained than in the preceding ; and moreover the
mineral is infusible.
2. STRUCTURE NOT MICACEOUS.
a. Hydrous.
a. NO REACTION FOR PHOSPHORUS, OR BORON.
t Hardness, with, the exception of a variety of serpentine, 1 to 3 ?
lustre not at all vitreous,
CHLORITES, p. 318. H.=2-25. Here fall the massive granular
chlorites, olive-green to black in color, of the species penninite, ri-
pidolite, prochlorite; B.B. reaction for iron, fuses with difficulty;
yields much water.
VERMICULITE, p. 317. H.=1-1'5. Granular massive forms of
vermiculite.
TALC, p. 304. H.=1-1'5. Here falls steatite (soapstone) or massive
talc, of white to grayish green and dark green color, granular to
cryptocrystalline in texture. B.B. fuses with great difficulty, and
yields only traces of water ; no reaction for iron, or only slight.
PYROPHYLLITE, p. 306. Grayish white, massive or slaty ; B.B.
like the crystallized, p. 403, in its difficult fusibility and little water
yielded, but does not exfoliate.
SERPENTINE, p. 307. H.=2'5-4; G. =2 "36-2 '55 ; olive-green;
ywh green ; blackish green, white ; B.B. fuses with difficulty on
thin edges ; yields much water.
DETERMINATION OF MINERALS. 405
FINITE, p. 312. H.=2-5-3'5; G.^2-6-2'85 ; lustre feebly waxy;
gray, gnh, bnh. B.B. fuses; yields water.
DAMOURITE, p. 313. Same as crystallized, p. 403, but in mas-
sive aggregation of scales.
tt Hardness 3-5 to 6'5 ; lustre often pearly on a cleavage surface,
but elsewhere vitreous.
PREHNITE, p. 295. H.=6-6'5; G.=2'8-3; pale green to white;
crystals often barrel -shaped, made of grouped tables ; B.B. fuses
very easily ; decomp. by H Cl.
PECTOLITE, p. 293. K.=5 ; G.=2'68-2 8 ; white ; divergent fibrous,
or acicular; B.B. fuses very easily; gelatinizes imperfectly with
HC1.
APOPHYLLITE, p. 294. H.=4'5-5 ; G.=2 3-2'4 ; white, gnh, ywh,
rdh ; dimetric, one perfect pearly cleavage transverse to prism ;
B. B. fuses very easily ; a fluorine reaction ; decomp. by H Cl.
OHABAZITE, p. 300. H.=4-5 ; G.=2-2 2 ; rhombohedral, vitreous;
white, rdh ; B. B. fuses easily ; decomp. by H Cl.
HARMOTOME, p. 301. H.=4'5; G.=2'44; white, ywh, rdh;
crystals twins, usually cruciform ; B.B. fuses not very easily ; vitre-
ous in lustre ; decomp. by H Cl.
STILBITE, p. 302. H.=3'5-4 ; G.=2-2 2 ; white, ywh, red ; crys-
tallizations often radiated-lamellar ; one perfect pearly cleavage ;
B. B. exfoliates, fuses easily ; decomp. by H Cl.
HEULANDITE, p. 303. H.=35-4; G.=22; in oblique crystals,
with one perfect pearly cleavage ; B.B. same as for stilbite.
EUCLASE, p. 288. H. =7-5 ; G. =81 : in glassy transparent mono-
clinic crystals; B.B. fuses with great difficulty ; gives water in
closed tube when strongly ignited.
Prehnite, apopliyllite, chabazite, harmotome, heulandite, and enclose
never occur in fibrous forms.
ft. REACTION EITHER FOR PHOSPHORUS OR BORON.
VIVIANITE, p. 184. H.=15-2; G.=2'55-7; monoclinic with one
perfect cleavage ; white, blue, green ; B.B. fuses very easily, the
flame bluish green, a gray magnetic globule ; in H Cl sol.
ULEXITE, p. 212. H.=l; G. =1 -65 ; white, silky, in fine fibres ;
B.B. fuses very easily, and moistened with sulph. acid flame for an
instant green, "owing to the boron present ; little sol. in hot water.
PRICEITE (p. 212) is in texture and color like chalk ; similar to
ulexite in green flame B.B.
Borax and Sassolite are other soft minerals containing boron, but
these have taste.
I. Anhydrous.
a. B.B. the flame lithium-red.
SPODUMENE, p. 248. H.=6'5-7; G.=813-8'19; white, gyh, gnh
white, monoclinic (like pyroxene), with /A 7=87°, and perfect
cleavage parallel to 7 and i-i; B.B. swells and fuses.
406 DETERMINATION OF MINERALS.
PETALITE, p. 248. H.=6-6'5; G.=2-4-2'5; white, gray, rdh,
gnh ; B.B. becomes glassy and fuses only on the edges.
HEBRONITE, AMBIiYGONITE, p. 199. H. =6 ; G. =3-31 ; moun-
tain green, gyh, white, bnh ; B.B. fuses very easily, reaction for
fluorine.
TRIPHYLITE, p. 190. H.=5 ; G.=3'5-3'6 ; greenish gray, bluish,
often bnh black externally ; B.B. fuses very easily, globule mag-
netic ; with soda, manganese reaction.
LEPIDOLITE, p. 268. H.=2 5-4 ; G.=2'8-3 ; micaceous, also scaly-
granular; rose-red, pale violet, white, gyh; B.B. fuses easily;
after fusion gelat. with H Cl. Some Uotite, p. 266, gives the lithia
reaction.
(3 . B.B. boron reaction (green flame).
TOURMALINE, p. 282. H.=7 ; G.=2 9-3'3 ; rhombohedral, prisms
with 3, 6, 9 sides, no longitudinal or other distinct cleavage ; black,
blue black, green, red, rarely white ; lustre of dark var. resinous ;
B.B. fusion easy for dark var. and diff. for light.
AXINITE, p. 264. H. =6*5-7 ; G.=3 27 ; triclinic, sharp-edged, glassy
crystals ; rich brown to pale brown and grayish ; B.B. fuses readily ;
with borax violet bead.
BORACITE, p. 206. H.=7 ; G.=2'97 ; isometric ; white, gyh, gnh ;
lustre vitreous ; fuses easily, coloring flame green.
Dariburite, p. 264, is another boron silicate.
y. B.B. reaction for titanium.
TTTANTTE, p. 290. H.=5-5'5 ; G.=3'4-3'56 ; monoclinic ; usually
in thin sharp-edged crystals ; brown, ywh, pale green, black ;
lustre usually subresinous ; B.B. fuses with intumescence.
3. Reaction for fluorine or phosphorus.
CRYOLITE, p. 197. H.=2'5 ; G.=2'9-3 ; white, rdh, bnh ; fuses in
the flame of a candle ; soluble in sulph. acid which drives off hydro-
gen fluoride, a gas that corrodes glass.
FLUORITE, p. 208. H.=4; G.=3-3'25; isometric, with perfect
octahedral cleavage, and massive ; white, wine-yellow, green, pur-
ple, rose-red, and other bright tints ; phosphoresces ; when heated,
decrepitates ; B.B. fuses, coloring the flame red ; after ignition,
alkaline.
Lepidolite (p. 268), Amblygonite (p. 199), also give a fluorine re-
action.
APATITE, p. 212. H.=4'5-5 ; G. =2 '9-3 '25 ; often in hexagonal
prisms ; pale green, bluish, yellow, rdh, bnh, pale violet, white ;
B.B. fuses with difficulty, moistened with sulph. acid and heated,
flame bluish green from presence of phosphorus ; sometimes reaction
for fluorine.
S. Reaction for iron.
GARNET, p. 256. H. =6 "5-7 "5 ; G.=3'15-4'3 ; isometric, usually in
dodecahedrons and trapezohedrons, also massive, never fibrous or
columnar ; red, bnh red, black, cinnamon red, pale green, to emerald-
DETERMINATION OP MINERALS. 407
green, white. B.B. dark-colored varieties fuse easily, and give iron
reaction, but emerald-green var. almost infusible ; a white to yellow
massive garnet is hardly determinable without chemical analysis.
VESUVIANITE (Idocrase), p. 261. H.-6'5 ; G. =3*35-3-45 ; dimetric
and often in prisms of four or eight sides, never fibrous ; brown to
pale green, ywh, bk ; B.B. fuses more easily than garnet ; reaction
for iron.
EPIDOTE, p. 262. H.=6-7; G.=3'25-3'5; in monoclinic cryst.
and massive, .rarely fibrous ; unlike amphibole in having but one
cleavage direction ; ywh green, bnh green, black, rdh, yellow, dark
gray ; B.B. fuses with intumescence.
AMPHIBOLE, dark varieties including Jwrriblende, actinolite, and
other green to gray and black kinds, p. 249. H.--=5'6 ; G.=3-3'4 ;
monoclinic, in short or long prisms, often long fibrous, lamellar, and
massive, prisms usually four or six sides, /A/=124i°, cleavage par.
to 1 ; B.B. fusion easy to moderately difficult.
ANTHOPHYLLITE, p. 252, like hornblende ; bnh gray to bnh
green, sometimes lustre metalloidal ; B.B. fuses with great diffi-
culty.
PYROXENE, augite, and all green to black varieties, p. 245.
^ H.=5-6 ; G.=r3'2-3'5 ; monoclinic, in short or oblong prisms, lamel-
lar, columnar, not often long, fibrous or asbestiform, prisms usually
with four or eight sides, /A 7=87° 5', cleavage par. to 1 ; B.B. as
in hornblende.
HYPERSTHENE, p. 244. H.=5-6; G.=3'39; cryst. nearly as in
pyroxene, but trimetric, usually foliated massive, also fibrous ; bnh
green, gyh black, pinchbeck-brown ; B.B. fuses with more or Jess
difficulty. Bronzite, p. 244, is similar and almost infusible.
IOLITE, p. 264. H.=7-7'5 ; G. =2 "6-2 7 ; blue to blue violet ; looks
like violet-blue glass ; B.B. fuses with much difficulty.
Tourmaline, much Titanite, and lhaite (p. 263), B.B. give iron re-
action.
C. No reaction for iron.
SCHEELITE, p. 212. H.=4'5-5 ; G.:=5-9-6-l ; ywh, gnh, rdh, pale
yellow ; lustre vitreous-adamantine ; fuses on the edges with great
difficulty.
SCAPOLITES, p. 268. H.=5'5-6; G.=2'6-2'74; dimetric, often
in square prisms ; white, gray, gnh gray ; B.B. fuses easily with in-
tumescence.
ZOISITE. p. 263. H=6-6'5; G.— 3'l-3'4; trimetric, oblong prisms
and lamellar massive, cleavage in only one direction.
AMPHIBOLE, white var. (tremolite), p. 249. Same as for other
amphibole (above), except in color ; B.B. fuses.
PYROXENE, white var., p. 215. Same as for other pyroxene (above),
except in color ; B.B. fuses.
ORTHOCLASE, p. 278. H.=6-6'5 ; G.=2'4^2'62 ; monoclinic, stout
cryst., and massive, never columnar, two unequal cleavages, the
planes at right angles with one another, and cleavage surfaces never
finely striated, as seen under a pocket lens or microscope ; white,
gray, flesh-red, bluish, green ; B.B. fuses with some difficulty.
408 DETERMINATION OF MINERALS.
ALBITE, p. 277, OLIGOCLASE, p. 276. H.=6; G.=256-2'72;
triclinic, but cryst. as in orthoclase, except that the two cleavage
planes make an angle of 93i° to 94°, and one of them has the surface
striated ; white usually, flesh-red, bluish ; B.B. fuse with a little
difficulty ; not acted on by acids.
LABRADORITE, p. 276. H.=:6 ; G.=2'66-2'76 ; triclinic, like albite
in cryst., and nearly in cleavage angle, 93° 20', and in striae of
surface ; white, flesh -red, bnh red, dark gray, gyh brown ; B.B.
fuses easily ; decomposed by HC1 with difficulty.
ANORTHITE, p. 275. H =6-7 ; G.=2'66-2'78 ; cryst, and stria?
as in albite, cleavage angle 94° 10' ; white, gyh, rdh ; B.B. fusion
difficult ; decomposed by HC1 with separation of gelat. silica.
MICROCLINE, p. 278. Very near orthoclase in all characters, but
triclinic, cleavage angle differing only 16' from a right angle, and
surface of most perfect cleavage striated, but striae exceedingly
fine, often difficult to detect with a good pocket lens, and requiring
the aid of a polariscope ; color white, gray, flesh-red, often green.
For optical distinctions of FELDSPARS, see p. 274.
EUCLASE, p. 288. H. =7'5; G.=8'l ; in monoclinic crystals, with
one perfect diagonal cleavage ; pale green, to white, bnh ; trans-
parent ; becomes electric by friction.
ON ROCKS.
I. CONSTITUENTS OF EOCKS.
ROCKS are made up of minerals. A few kinds consist of
a single mineral alone : as, for example, limestone, which
may be either the species calcite or dolomite ; quartzyte
(along with much sandstone), which is quartz ; WDAfelsyfet
which is orthoclase. But even these simple kinds are sel-
dom free from other ingredients, and often contain visibly
other minerals. Nearly all kinds of rocks are combinations
of two or more minerals. They are not definite compounds,
but indefinite mixtures, and hardly less indefinite than the
mud of a mud-flat. The limits between kinds of rocks
are consequently ill-defined. Granite graduates insensibly
into gneiss, and gneiss as insensibly into mica schist and
quartzyte, syenyte into granite, mica schist into hornblende
schist, granite also into a compact porphyry-like rock, and
trachyte; and so it is with many other kinds. The fact
is a chief source of the difficulty in studying and defining
rocks, and especially the crystalline kinds. The different
rocks are not species in the sense in which this word is used
in science, but only kinds of rocks.
The minerals which are the chief constituents of rocks
are of two classes : (A) the Siliceous; (B) the Calcareous.
A. The siliceous are as follows :
1. Quartz, which probably makes up one-third of the
rocky material of the crust of the globe.
2. The Feldspars (p. 272) ; of which orthoclase (with
microcline) is most abundant ; next to it, oligoclase and
labradorite ; and next alb it e, andesite, and anortMte.
3. The Micas (p. 205) : muscovite and biotite, of equal
prominence, the others much less common.
4. Ampliibole and Pyroxene species (p. 245, and beyond) :
especially hornblende or black amphibole, and augite or
409
410 DESCRIPTIONS OP ROCKS.
black pyroxene ; also the green hornblende or actinolite; the
green foliated hornblende called xmaragdite, and the foli-
ated pyroxene sometimes wrongly called hypersthene, and
another variety called diallage; also occasionally the species
Jiypersthene and cnstatite.
5. The Felclspar-rlike minerals, nepJielite (p. 269) and leu-
cite (p. 271), which are related in constituents and quan-
tivalent ratios to the feldspars, alumina being the only ses-
quioxide base, and lime, potash, and soda the protoxide bases
afforded in analyses ; the atomic ratios for the protoxides,
sesquioxide, and silica being in nepheiite, 1 : 3 : 4, as in
anorthite ; and in leucite 1 : 3 : 8, as in andesite. Also, less
abundantly, Sodalite (p. 270), which has essentially the
ratio of anorthite and nephelite.
6. Minerals of the Saussurite group. These jade-like
species differ from the feldspars — (1) in being always fine-
grannlar in texture; (2) in having a high density, G-. —
#•9-3 '4 ; in varying from the feldspar type chemically.
They are near some soda-lime feldspars in constituents, but
not ahvays in the atomic relations of the constituents, nor
in the absence uniformly of magnesia. There are two
prominent kinds. One is between anorthite and zoisite in
composition (see p. 263) ; yet, unlike .these minerals, its
analyses afford several per cent, of soda and some magnesia.
The second approaches labradorite ; Delesse obtained for a
specimen from Mt. Genevre (Alps), Silica 49 '73, alumina
29*65, iron protoxide 0*85, magnesia 0*56, lime 11*18, soda
4-04, potash 0*24, water (with a little C02) 3-75 ; and a
Silesian specimen afforded Vom Rath nearly the same result.
A third kind from Corsica, according to Boulanger's analy-
sis, has nearly the same composition as zoisite. A. fourth
is jadeite (p. 263), a stone occurring in the Swiss lake-dwell-
ings— but not yet found in the saussurite rocks of Switzer-
land.
The saussurite of Siberia and the Alps has been observed
to have sometimes the form of twins of a triclinic feldspar.
This, and the texture, density, and composition, show that
saussurite is, in part at least, pseudomorphous, and, in somo
regions, after labradorite. By some peculiar conditions in
the process of metamorphism — perhaps long-continued heat
with an unusual amount of moisture — the feldspar crystal-
lizations that formed in the incipient stages of the process
were afterward changed to a species of higher density and
DESCRIPTIONS OP ROCKS. 411
different molecular nature ; in other words/to saussurite.
Some of the material appears to be still labradorite.
7. The iron-bearing minerals, Epidote (p. 262), Garnet
(p. 250), Chrysolite (p. 255), which characterize some varie-
ties of rocks.
B. The calcareous species are calcite or calcium carbonate
(p. 215), in various states of impurity ; and dolomite or cal-
cium-magnesium carbonate (p. 219), which in its rock-form
is undistinguishable in external aspect from calcite.
Gypsum, or hydrous calcium sulphate, is also a consti-
tuent of beds among rocks, and should have its place in the
list, although not strictly embraced under the term calca-
reous.
Of the siliceous minerals, orthoclase (with microcline),
and the two micas, muscovite and biotite, are related in com-
position, in that each affords 10 per cent, or more of pot-
ash. Leucite is another allied potash-alumina silicate, even
richer in potash than orthoclase, it containing 17 to 21 per
cent. The rocks characterized by these minerals are hence
rich in potash.
Albite and oligoclase, and also sodalite, afford much soda,
the first two usually 8 to 12 per cent. , and sodalite, 20 to
25 per cent. Nephelite (elaeolite) is also a soda mineral
related to the feldspars ; but, with 15 to 16 per cent, of soda,
there are 5 or 6 of potash ; rarely the alkali afforded is all
soda.
The ordinary kinds of hornblende and pyroxene, on the
contrary, afford little or no soda or potash. They thus dif-
fer widely from the potash and soda species just mentioned,
and naturally characterize for the most part a distinct series
of rocks.
Much importance has been allowed in lithology to the
distinction of foliated under the species hornblende and
pyroxene ; when, in fact, neither in mineralogy, as all
treatises admit, nor in lithology, has it more than a very
subordinate value. The character obtained this distinction
before it was fully understood that the foliated forms were
identical in composition with those in crystals or in massive
forms.
Hornblende does not differ from augite in composition ;
but since the difference in crystallization is connected with
a difference in the physical conditions attending their origin,
DESCRIPTIONS OF ROCKS.
and since rocks of each kind often have a vast extent over
the earth's surface, the distinction as to whether a rock is
hornblendic or augitic is of prominent geological interest.
II. CLASSES OF ROCKS.
Kocks are of different classes, according to their texture
and origin.
1. FBAGMENTAL. A large part of common rocks were
formed of sand, or pebbles and sand, and are only consoli-
dated sand-beds or gravel-beds ; and other related kinds are
more or less consolidated mud-beds or clay-beds. The mud-
beds of an estuary, or of the shallow seas off a coast, and the
stratified sand and gravel accumulations of sea-shores and
valley formations, are precisely the kind of material which
by consolidation have made the fragmental rocks, the most
abundant rocks of the earth's surface. Each pebble, grain
of sand, and constituent particle of the mud, was derived
from preexisting rocks, and is either an actual fragment from
those rocks, or else a fragment altered by more or less com-
plete decomposition. The rocks are hence called fragmen-
ted. The pebbles, and often the sands, have a worn surface,
and this fact, together with the structure of the beds, affords
evidence that they are fragmental. They are also the sedi-
mentary rocks of geology ; for the material was for the
most part carried and dropped by waters as sediment is
carried and dropped — the waters mainly of the ocean which
then covered the continents.
2. CKYSTALLINE. Other rocks are crystalline. The grains
are angular instead of worn, and they crowd upon or pene-
trate one another because made in one process of crystal-
lization. They are generally angular over a fractured sur-
face because of the cleavage planes, like the grains of a
surface of broken iron. Granite, trap, white marble are ex-
amples of crystalline rocks. When such a rock is distinctly
granular there is little difficulty in deciding upon its being
a crystalline rock. If too fine-grained for a positive conclu-
sion with the aid of a pocket-lens, the doubt may usually
be removed by tracing it along to places where it is coarser ;
and if none such offers, by the preparation of thin slices for
microscopic examination.
Crystalline rocks have received their crystalline texture
in different ways.
DESCRIPTIONS OF ROCKS. 413
A. By cooling from fusion. The rocks thus made are called
IGNEOUS or ERUPTIVE rocks, as, for example, lavas or vol-
canic ejections, and all rocks that, like trap, have come up
melted through fissures in the earth's rocky crust. The
depth of the liquid source of such eruptions is unknown.
The fact that, at one epoch, material of the same kind has
sometimes been ejected at intervals along a band of country
a thousand miles in length, from northeast to southwest, as
on the Atlantic coast from Nova Scotia to South Carolina,
indicates considerable depth in such cases. They may be
older rocks melted over and thrust up to the surface ; but if
so, the remelted rocks were in many cases those situated deep
in the earth's crust, far below all the strata of its surface.
B. By subjection to long -continued heat without fusion,
making METAMORPHIC rocks. Through this means fragmen-
tal or sedimentary strata, over areas of thousands of square
miles, and many thousands of feet in depth, have been
simultaneously crystallized, turning the beds that were
originally made from sand, gravel, or mud, into granite,
gneiss, and other related rocks, and compact limestones
into marble. The rocks at the time of the change were
generally undergoing extensive mountain-making uplifts,
and it is supposed that the friction attending the movements
of the strata may have been an important source of heat for
the change or crystallization ; and that the diffusion of this
heat was due to the moisture which abounds in unaltered
sedimentary beds. Metamorphic strata retain their former
relative order of superposition, having been crystallized in
place, that is, without fusion. Where granite has been the
result, it is probable that the material was sometimes re-
duced to a pasty state, so that all lines of the original bed-
ding were obliterated ; but even in that case, the granite is
generally in the place occupied by the material before crys-
tallization. In other cases, including that of some granites,
there was not even this degree of approach toward the origi-
nal condition of the true eruptive rock. During the upturn-
ing, the rocks were much fractured, and the fissures so^made
became filled with the materials of the adjoining or subjacent
rocks, through the aid of the heated moisture present, mak-
ing veins ; and such veins differ widely from those, called
'dikes, that were made when the fractures descended to re-
gions of melted rock, so that the fissures became filled with
ejected material.
414 DESCRIPTIONS OP ROCKS.
Rocks thus metamorphosed or rendered crystalline are
distinguished as metamorphic rocks.
C. By chemical deposition. Waters often hold calcareous
material in solution. When carbonic acid (carbon dioxide)
is present in any waters, those waters will take up calcium
carbonate, and make calcium bicarbonate ; and when the
waters evaporate, the calcium carbonate is deposited. This
is the propess by which stalactites and stalagmites (p. 216)
have been made, and so also calcareous tufa and travertine
(p. 432). The Gardiner River region in the Yellowstone
Park is noted for its deposits of travertine.
In geyser regions there are siliceous deposits made by the
hot waters, as stated on page 240 ; and these also are exem-
plified in the Yellowstone Park.
Beds of tripolite (p. 241) sometimes become consolidated
and converted into chert by the waters that penetrate them
— these waters containing a trace of alkali or enough to
enable them to dissolve some of the tripoli silica, and then
a deposition taking place causing consolidation. The flint
and chert of the rocks has probably had generally this ori-
gin.
3. CALCAREOUS ROCKS or LIMESTONES. Compact lime-
stones are commonly of fragmental origin. They have been
made mainly out of worn or ground-up shells, corals, and like
calcareous material of organic origin — the movements of the
ocean having been, and still being, the grinding agency.
They were consolidated through the ocean's waters which
penetrated the beds taking up a little calcareous material,
and then depositing it again. It is, in one sense, metamor-
phism. But when such compact limestones experience true
metamorphism, at the same time with other strata, they be-
come distinctly crystalline-granular, and often very coarsely
so, making crystalline limestone or marble.
III. ON SOME CHARACTERISTICS OF ROCKS.
1. CRYSTALLINE TEXTURE. Crystalline texture varies in
coarseness from that in which crystalline grains are visible
only under high magnifying power, and the rock is as apha-
nitic (p. 60) as flint, to that in which they are very coarse.
Not unfrequently one of the minerals appears in large crys-
tals, distributed through the mass — the mass being made of
DESCRIPTIONS OF HOCKS.
415
the rest of the material in a comparatively fine-grained con-
dition. The porphyry of the ancients was a rock of dark
feldspathic base, sprinkled all through with light-colored
feldspar crystals ; and, from this fact, any metamorphic or
igneous rock containing such disseminated crystals of a
feldspar is said to be porphyritic.
The following figures illustrate three varieties of porphy-
ritic rock. The first represents a specimen of the red an-
tique porphyry of Egypt — now often called Rosso antico —
the rock which gave the name porphyry to geology, a kind
Rosso Antico. Oriental Verd-antique. Porphyritic gneiss.
much used by the Romans (though not by the Greeks or
Egyptians), and quarried by them in the mountain Djebel-
Dokhan, twenty-five miles from the lied Sea, in latitude
27° 20'. Through the red aphanitic base small whitish
crystals of orthoclase are thickly distributed. Figure 2 is
from a polished piece of green antique poryphyry. The
feldspar crystals are comparatively large, and the compact
base has a dark green color. Figure 3 represents a large
crystal of orthoclase with the gneiss about it, from porphy-
ritic gneiss. The feldspar crystals in porphyritic gneiss or
granite sometimes measure three inches by one and a half,
and again only a fraction of an inch. These orfchoclase
crystals, as often in other porphyritic rocks, are twin crys-
tals, the plane of cleavage of one half making an angle of
52° 23' with that of the other half. Occasionally large crys-
416
DESCRIPTIONS OF ROCKS.
tals contain small crystals of mica distributed in one or
more layers concentric with the sides.
The clegree of coarseness in the texture of a crystalline
rock has been determined chiefly by the rate of cooling,
in connection with the nature of the material. Relatively
rapid cooling produces a fine texture or grain, and very slow
cooling a coarser.
A melted rock may cool too rapidly to become stony
throughout, or to become stone at all; and, in the latter
case, the material made is glass. Common melted glass
would be stone on cooling if the process were gradual
enough.
Figures 4 to 6 represent much-magnified views afforded
by transparent slices from glassy rocks, in three of their
stages between the pure glassy and the true stony state. In
4, from obsidian, or volcanic glass, of Greenland, there
are radiating clusters consisting of hair-like microiites (or
microscopic minerals), called tricliites (from the Greek tlirix,
hair), such as are common in all obsidians. Fig. 5 shows
the texture of a variety of pearlite, a light gray rock of
6.
Tricliites in ob-
sidian.
Trichites and Fluidal
texture in Pearlite.
Microiites in a Pitchstone
from Weisselberg.
pearly lustre from the Montezuma Range in the Nevada
Basin, as figured by Zirkel; in this, trichite clusters, besides
being very numerous, are arranged in lines or planes, and
some of the tricliites arc powdered with pellucid grains, or
globnlites, which are incipient crystals. Zirkel represents
another kind in which the radiating trichites are each a
string of globulites. Fig. 6 represents a pitchstone from
DESCRIPTIONS OP ROCKS. 417
Weisselberg (from Rosenbusch), in which the microlites are
distinctly crystalline in form, and some give evidence that
they are feldspar crystals, others that they are augite and
magnetite, and indicate that the rock is intermediate be-
tween a glass and a doleryte. Thus there is a passage to
ordinary stone. Trap or doleryte has been used for making
bottle-glass ; and attempts have been made to manufacture
glass directly from a variety of granite containing little
quartz.
Eruptive rocks, that have come up through fissures,
often have glassy particles among the stony in the part
near the walls of the fissure when not so through the inte-
rior of the mass; and many such rocks, covering large areas,
have glassy grains among the stony grains, or a glassy mag-
ma, because the cooling generally was not slow enough for
complete lapidification ; or they have an undefined base,
when examined in thin slices, which the microscope does
not resolve into crystalline grains. !Such portions of a rock
are described as unindivi dualized. An unindividualized
base exists in the basalt of Truckee Valley, the character of
a slice from which, highly magnified, is given in fig. 7, from
Zirkel ; feldspar crystals, of their usual rectangular forms
(part of them sanidin), one of the largish crystals of chryso-
lite, and smaller irregularly-shaped augites, are imbedded in
a base which consists of a glass-like substance ; and in this
material there are extremely small globulite grains which
are globules of devitrified glass or incipient crystals. The
glassy unindividualized base occupies the spaces among the
crystalline portions.
vrhese differences in crystalline texture are of small im-
portance compared with differences in mineral and chemi-
cal composition. They are results of accidents, and, at
the best, lead only to a distinction of varieties among kinds
of rocks. The presence of a little glass, or of disseminated
large crystals in a porphyritic way, does not make the rock
essentially different in kind. If, however, the glassy na-
ture is manifest in the external appearance of the mass, ib
is convenient to call the rock by a separate name.
Porphyritic rocks are sometimes named as if porphyry
was a distinct kind of rock, or as if the porphyritic section
of a kind of rock merited special prominence. But, as re-
cognized beyond, "felsyte-porphyry " is porpliyritic felsyte ;
f ( dioryte-porphyry" is porpliyritic dioryte ; " diabase-por-
418
DESCRIPTIONS OF ROCKS.
phyry "is porpliyritic diabase, or, since diabase cannot be
distinguished mmeralogically from doleryte, it is porpliy-
ritic doleryte ; and, in these and other like cases, the being
porphyritic is a characteristic of minor value.
Sometimes igneous rocks exhibit under the microscope a
fluidal texture; that is, the material, when examined in
sections, shows wavy lines or bands, which are evidence of
a former fluid state, and of movement or flowing when in
that state. One variety of this texture is represented in fig-
ure 8 (from Zirkel), giving a magnified view of an eruptive
7.
8.
ill
Basalt with the base unindividu-
alized.
" Rhyolyte ;" Fluidal texture.
rock from the head of Louis Valley, Nevada ; and another
in figure 5, p. 416. Such rocks have been comprised under
the general name of Rhyolyte (from the Greek for flowing) ;
but this fluidal texture is' presented by rocks of different
mineral constitution, and is hence not a proper basis for a
kind of rock.
2. ANHYDROUS AND HYDROUS CRYSTALLINE ROCKS.—
Some eruptive rocks, like doleryte or trap, occur both an-
hydrous and hydrous. The latter, unlike the former, have
the constituent minerals clouded in aspect, however thinly
sliced, and often changed in part to a green chlorite — a hy-
drous mineral — and also sometimes to other hydrous species.
Such rocks, moreover, have less lustre, and very frequently
they are amygdaloidal — that is, contain little cavities that
are often almond-shaped (the Latin amygdalum meaning
DESCRIPTIONS OF ROCKS. 419
almond), which were made by steam, or vapor of some kind,
and are now occupied by minerals. This hydrous or chloritic
condition is due to alteration, and hence such rocks are
properly only varieties of the anhydrous instead of being
distinct kinds.
The change was probably occasioned by subterranean wa-
ters, such as exist as streams among the earth's strata, that
were encountered by the liquid rock when on its way up a
fissure toward the surface. Hydrostatic pressure prevented
the waters from being driven back by the heat, and conse-
quently th* vapors were forced to penetrate the igneous
mass. In the region of New Haven, Conn. — lying at the
south extremity of the Connecticut Valley — the Triassic
trap-dikes of the western border of the region, and those
outside of the Trias, east or west, in the metamorphic
rocks, are anhydrous, while those in the middle of the valley
and east of this are mostly hydrous, showing a difference in
exposure to the waters according to the geographical position
of the dikes in the valley. Of two parallel ranges of dikes,
not half a mile apart, and following concentric curves in
their courses (situated twenty miles and more north of New
Haven), one (as Percival recognized) is amygdaloidal and
hydrous, and the other nearly anhydrous; and the positions
of the two kinds, there and elsewhere in the Connecticut
Valley, indicate a general relation between the direction of
the present valleys and that of the subterranean water-chan-
nels of Mesozoic time.
In very many places coal-like " inspissated bitumen"
occurs in the amygdaloidal cavities, which was apparently
derived from mineral oil that the action of the heat on the
Triassic carbonaceous shales (in some places abounding in
fossil fishes) had caused to rise in vapors and penetrate the
melted rock. The carbonic acid of the calcite that so often
constitutes the amygdules probably came from the action
of the heat on limestone encountered at the same time.
The deoxidizing action of the carbohydrogen vapors is sup-
posed by J. Lawrence Smith to account for the metallic
iron found in some trap or doleryte. The minerals which
constitute the amygdules (see p. 297) are largely such as
may have been made by the aid of heat and moisture out of
the minerals of the rock itself at the points where they occur.
The water that caused the change could not have come from above
after the rock was cooled ; for the slight surface decomposition the
420 DESCRIPTIONS OF ROCKS.
anhydrous trap now undergoes shows that such waters do not make
their way down : and moreover the results could not have been pro-
duced without heat. The trap has not been subjected to a metamor-
phic process ; for the Triassic beds are unaltered sandstone. The water
was not from the deep-seated source of the erupted trap, for, if so, the
dikes would have been all of one kind, instead of being part hydrous
and part anhydrous, and the former locally distributed just as subter-
lanean streams of water are likely to be.
In the case of hydrous metamorphic rocks, whether con-
taining chlorite, talc, or a hydrous mica, the hydrous min-
erals were, with rare exceptions, made at the time of the
crystallization, and are not a consequence of subsequent al-
teration.
3. DURABILITY IK ROCKS. — Durability in a rock is due
largely (1) to compactness and fineness of texture; and
(2) to the absence of any ingredient or mineral that is liable
to oxidation. As far within a rock as water and air can gain
access, degradation will always be going on, and most rapidly
in all crevices along their walls. Alternate melting and freez-
ing will be one means of destruction ; direct chemical action of
moist air, especially the carbonic acid it contains (p. 108),
another ; the wedging apart of grains caused by the slightest
deposits and oxidations, through infiltrated waters, another.
In granite the carbonic acid may take the alkalies out of
the feldspar, and so occasion the destruction of the rock.
Hence the practice of testing the durability of a stone for
architectural purposes, by putting it into water, and then
weighing it, after some days of exposure, to see whether it
has gained in weight, is a good one.
Fineness of grain gives further protection against destruc-
tion. Alternate heating and cooling in the daily passage of
the sun is a destroying agency of great effect, especially 011
coarse-grained kinds. Eocks have often retained the glacier
markings upon them perfectly fresh until now, when they
have had a covering of two or three feet of earth ; and they
have lost such markings after a few years of exposure. This
happens often where there is no true decomposition or ox-
idation of the surface portion of the rock, and must be due
largely to the expansion and contraction caused by changing
temperature. The finer the grain of the rock the less the
chance for this action. There is no more durable rock than
a roofing-slate of good quality. Granites, when well pol-
ished, will usually resist long all weathering agencies.
DESCRIPTIONS OF ROCKS. 421
The presence of an oxidizable ingredient is a common
source of destruction. Pyrite occurs in grains or crystals
in almost all kinds of rocks ; and it generally oxidizes
easily whenever water and air get access to it. Only the
firmest crystals resist change, and these not always. A rock
containing even a little pyrite can seldom be trusted for
architectural purposes. If a limestone contain a few per
cent., or even one, of iron or manganese replacing part of
the calcium, it has a source of destruction within it. The
iron and manganese are sure, after a while, to oxidize ; the
iron will give rusty stains, and the manganese turn it black,
and both will work destruction. A chemical trial is needed
to ascertain the fact as to the purity or not of the rock.
The presence of iron carbonate (siderite or spathic iron) is
the occasion, wherever it exists, of rapid decomposition as
far down as moisture and air can reach. This has been one
source of the changes producing the great beds of limonite
(like those of Western Massachusetts, Salisbury, Connecti-
cut, and other places), in which the rocks are sometimes de-
composed to a depth exceeding one hundred feet.
It is a fact to be remembered that a rock which has stood
the weather for centuries in its native exposure is a safe
material for man's structures ; and one that is crumbling is
worth little or nothing.
Durability depends much on the climate. In Peru, even
sun-burnt bricks will last for centuries.
The resistance to crushing in rocks is ascertained by sub-
jecting cubes of a given size to pressure. 'In recent experi-
ments by P. Michelot,* Minister of Public Works in France
(whose trials numbered over 10,000), the most compact
limestones, weighing 2,700 kilograms per cubic meter, were
crushed by a weight of 900 kilograms per square centimetre.
Compact oolitic limestone of Bourgogne and some other
French localities, weighing 2,600 to 2,700 kilograms, bore
700 to 900 kilograms before crushing. Statuary and decora-
tive marbles bore 500 to 700 kilograms.
Of granitic rocks from Brittany, the Cotentin, the Vosges,
and the Central Plateau of France, weighing 2,600 to 2,800
kilograms, the best, which admitted of polishing, bore 1,000
to 1,500 kilograms; while the coarser granites of Brest and
* Exposition Universelle de 1873 a Vieimc, p. 401-432 ; and Annales des Pont* et
Chaussees, 1863, 1868, 1870.
422 DESCRIPTIONS OF ROCKS.
Cherbourg and the syenyte of the Vosges bore 700 to 1,000
kilograms ; and other coarse granites, in which the large
crystals of feldspar were in part decomposed, bore only 400
to 600 kilograms. The green porphyry of Ternuay (Haute
Saone), bore 1,360 kilograms; the "basalt of Estelle (Puy
de Dome), 1,880 kilograms.
In trials by Gen. Gilmore, trap of New Jersey required
to crush it 20.750 to 24,040 Ibs. a square inch (about 6 c.
m. sq.) ; granite of Westerly, R. I., 17,750 ; id. of Rich-
mond, Va., 21.250 ; syenyte of Quincy, 17,750 ; marble of
Tuckahoe, N. Y., 12,950 ; id. of Dorset, Vt., 7,612 ; lime-
stone of Joliet, 111., 11,250 ; sandstone of Belleville, N. J-,
10,250; id. of Portland, Ct., 6,950; id. of Berea, 0.,
8,300; id. of Amherst, 0., 6,650 ; id, of Medina, N. Y.,
17,250 ; id. of Dorchester, N. B., 9,150.
When absorbent rocks are thoroughly wet the weight re-
quired to crush them is greatly reduced. To crush wet chalk,
according to trials by Delesse, required only one-third what
it did when stove-dried ; and for the limestone, " calcaire
grossier," of Vitry and other localities, mostly one- third to
one-half. Tournaire and Michelot found, for the chalk of
the Paris basin, the pressure required when wet two-ninths
of that required when the rock had been dried at a tempera-
ture considerably above 212° F.
Use of the Microscope in the Study of Rocks. The study of
thin, transparent slices of rocks by the microscope is of in-
terest whether the crystalline rock be coarse or fine in tex-
ture ; but it is particularly important when of the latter
kind. There is no rock so opaque that it cannot be made
transparent, or at least translucent, in thin slices. Such
slices are examined by means of a polariscope-microscope.
The increased use of the microscope in the investigation of
rocks has led to the introduction, by way of distinction in
methods of study, of the word macroscopic. An investiga-
tion may be carried on macroscopically , that is, without the
use of a microscope, excepting a pocket lens ; or microscopi-
cally, that is, by the study of thin slices through the aid of
the microscope and polariscope.
The more important points ascertained by microscopic
methods, as regards the mineral constitution of a rock, are
the following :
1. The presence or not of quartz; of a feldspar; of a
chloi'ite.
DESCRIPTIONS OF ROCKS. 423
2. The distinction of a triclinic feldspar from ortlioclase,
the former showing in sections, cut in any direction ex-
cepting one, commonly several parallel spectrum bands, due
to multiple twinning in the crystal, while orthoclase shows
no bands of the kind, or at the most but two.
3. The presence or not of hornblende ; this mineral hav-
ing often cleavage lines meeting at angles of 124°, and being
dichroic.
4. The presence or not of pyroxene ; this mineral often
showing cleavage lines meeting at angles of 87° (nearly a
right angle), and being not dichroic, and usually distin-
guished in this way from hornblende.
5. The presence or not of mica, its cleavage lines and
dichroism affording distinctive characters.
G. The presence or not of chrysolite ; of magnetite, its
form being often octahedral, and single or grouped ; of
11.
Magnetite in grouped Liquid Carbonic Cube of Salt in a solu-
crystals. Acid. tion of the same.
points or portions having the nature of glass, and therefore
not polarizing light; of fluidal lines; of liquid carbonic acid,
and of various other inclusions. Fig. 9 shows a common
form of the grouping of microscopic magnetite crystals
in an eruptive rock. Fig. 10 represents a cavity in quartz
nearly filled with a liquid, b— the small bubble, c, showing
the part not occupied by it. When the liquid is carbonic
acid the air-bubble disappears on raising the temperatw-e to
86°-95° F. Carbonic acid requires a pressure, at 32° F., of
38-J- atmospheres to retain it in the liquid state ; and hence
occurs liquid only in quartz, topaz, and a few other miner-
als. Fig. 11 (from Zirkel) shows another cavity, containing,
besides a liquid, a little cube and microscopic hornblende-
like acicular crystals ; and the cube is supposed to be com-
mon salt in a solution of salt. Hexagonal prisms of apa-
tite (calcium phosphate) are detected by the microscope in
4.24: DESCIUI'TIONS OF HOCKS.
almost all kinds of igneous and metamorpliic rocks, includ-
ing trap or doleryte.
For a particular account of the distinguishing character-
istics of minerals studied by microscopic methods, reference
must be made to treatises on the subject.
IV. KINDS OF ROCKS.
1. Eocks are generally mixtures of two, three, or four
prominent mineral constituents, with also others, it may be,
of less importance. Each mineral adds a distinctive fea-
ture, and might be a reason for a new name. But it is
usual with lithologists to base the distinction into kinds of
rocks on the two chief minerals, and make the others acces-
sory species and the basis only of varieties. This method
is prompted by convenience, and also by the fact that the
more important characteristics are commonly contained in
two of the constituent minerals. It has many exceptions,
however, and particularly where a third mineral has special
peculiarities and abundance.
2. Difference in kind of rock is naturally based on dif-
ference in chemical or mineral constitution, and identity,
accordingly, on essential identity in this respect. Conse-
quently when there is no essential difference in chemical or
mineral constitution, there is no sufficient reason for a dis-
tinction in kind or a difference in name, unless the wide
distribution of a particular variety, and the permanence in
its characters, make the distinction in name a geological
necessity.
In accordance with this statement, the distinctions among
crystalline rocks of coarse or fine in texture ; of being por-
phyritic or not ; of containing glassy grains among the
stony or not ; of being foliated or not in crystallization, are
of little value compared with the real mineral constitution,
anda^p a fit basis only, at the best, for varieties. But the two
rocks of like composition, trachyte and felsyte, retain their
characteristics so widely, that geology needs both names,
and only demands that" their essential identity should be
held in mind.
The same kind of rock is in many cases both of metamor-
phic and eruptive origin ; still the difference of origin is
not a sufficient basis for a distinction of kind unless there
is some marked difference between them, and an extended
KINDS OF ROCKS. 425
distribution of each, that makes the case like that of tra-
chyte and felsyte. The author has proposed to use the pre-
fix meta for metamorphic kinds when a rock occurs both
metamorphic and eruptive ; but this is not intended to indi-
cate a distinction in kind, but only to abbreviate the qualify-
ing word metamorphic.
According to the principles above stated, a rock having
oligoclase or albite as its feldspar constituent cannot rightly
have the same name with one having either of the basic
feldspars, labradorite or anorthite, as an essential part,
although these feldspars are all embraced under the decep-
tive title of playioclase (p. 275). Between anorthite and
oligoclase there is a difference of 20 per cent, in the silica,
and the former is simply a lime feldspar ; and the contrast
is large also between labradorite and oligoclase. Again, for
a like reason, as already explained (p. 411), a mica-bearing
rock containing little or no hornblende cannot properly be
classed with hornblendic rocks.
3. It has been supposed that pre-Tertiary crystalline rocks
differed so decisively from the Tertiary and more recent,
that those of the two series should not bear the same name.
But geology knows nothing of any epoch of sudden transi-
tion in the mineral nature of eruptive rocks at the com-
mencement of the Tertiary era ; on the contrary, it shows
that the kinds made before and after this epoch are alike
in mineral constitution, and differ not always even in tex-
ture, but only in the greater prevalence after the Tertiary of
volcanic or subaerial ejected masses, and therefore of rocks
of the texture this involves. The distinction of doleryte
from diabase, with others similar, is of this chronological
kind. Rocks, like other objects in science, should evidently
be named from what they are, and not from the age in
which they may have been made.
4. Since quartz is the most abundant of all the minerals
of the globe, it is the least characteristic of the ingredient^ of
compound rocks. Eecent lithologists have made it, in sev-
eral cases, distinguish only a section under a kind of rock.
Thus, there are dioryte and quartz-dioryte, felsyte and
quartz- felsyte, trachyte and quartz-trachyte. On the same
principle there are syenyte and quartz-syenyte, as adopted
beyond.
5. The division of crystalline rocks into acidic and basic
rocks is explained on p. 274 The acidic afford on analysis
426 DESCRIPTIONS OF ROCKS.
55 per cent, or more of silica, and the basic usually less
than 52.
6. The feldspars are divided, according to their bases,
into (1) potash-feldspars, including orthoclase and micro-
cline ; and (2) those which may be designated soda-lime-
feldspars, namely the species albite, oligoclase, andesite,
labradorite, and anorthite, which yield either soda, or lime,
or both, on analysis. The term plagioclase has been used
for the latter ; but it is no longer applicable since microcline
is plagioclase. Under the heading potash-feldspars, as used
beyond, leucite also is included ; and under that of soda-
lime-feldspars, nephelite and sodalite, and also the minerals
of the saussurite group.
The kinds of rocks are described under the heads of —
1. FRAGMENTAL BOCKS, EXCLUSIVE 6F LIMESTONES.
2. LIMESTONES, OR CALCAREOUS EOCKS.
3. CRYSTALLINE EOCKS, EXCLUSIVE OF LIMESTONES.
No strongly denned limit exists between the fragmental
and crystalline rocks. But still they are for the most part
widely diverse in character and aspect.
In the names of rocks, the termination ite is here changed to yte, as
done in the author's " System of Mineralogy " (1868), in order to dis-
tinguish them from the names of minerals. Granite is excepted.
I. Fragmental Rocks, exclusive of Limestones.
1, Conglomerate. — A rock made up of pebbles or of coarse
angular fragments of rocks of any kind, (a) If the pebbles
are rounded, the conglomerate is a pudding-stone ; (b) if
angular, a breccia.
Conglomerates are named according to their constituents, siliceous
or quartzose, granitic, calcareous, porpltyritic, pumiceous, etc.
2r Grit.— A hard, gritty rock, consisting of coarse sand,
or sand and small pebbles, called also millstone grit, be-
cause used sometimes for millstones.
3. Sandstone. — A rock made from sand : a consolidated
sand-bed.
VARIETIES. — a. Siliceous or Quartzose ; consisting chiefly of quartz.
b. Granitic; made of granitic material or comminuted granite, c. Mi-
caceous ; containing much mica. d. Argillaceous; containing much
clay with the sand. e. Gritty ; hard and containing small quartz peb-
KINDS OF ROCKS. 427
bles. f . Ferruginous ; containing iron oxide and having its red color,
g. Concretionary ; made up of concretions, h. Laminated ; made up
of thin layers or laminae, or breaking into thin slabs, a characteristic
most prominent in argillaceous sandstones, i Friable ; crumbling in
the fingers, j. Fossitiferous ; containing fossils.
The paving stone extensively used in New York and the neighbor-
ing States is a laminated sandstone, of the upper part of the Hamilton
group in geology, quarried just south of Kingston, and at many other
places on the west side of the Hudson River. The rock is remarkable
for its very even lamination. In Western New York and in Ohio, the
Devonian sandstones, above the Hamilton group, together with the
Waverly group, afford a similar flag-stone. The " brown-stone" used
much in New York and elsewhere for buildings, is a dark-red sand'
stone from the Triassic formation, and is quarried at Portland, Conn.,
on the Connecticut River, opposite Middletown. A lighter-colored
" brown-stone " or "free-stone," of the same age, also much used for
buildings, comes from Newark, Belleville, Little Falls, and other points
in Central New Jersey. The handsome sandstone of light olive-green
tint, much employed in architecture, is from the Lower Carboniferous
group in New Brunswick. The soft white sandstone, in much esteem
among architects because so easily cut and carved, comes from Ohio
quarries, in beds of the Carboniferous ; it is mostly from a bed about
sixty feet thick, called the " Berea grit/' and is obtained at Bereaand
Independence in Cuyahoga County, and Amherst in Lorain County, and
elsewhere.
Pyrite is often present in sandstones used for building, and has de-
faced, and is destroying, many a beautiful structure by its oxidation,
and the consequent decay of the rock.
Sandstones absorb moisture most easily in the direction of the bed-
ding or grain, if there is any distinct bedding ; and hence the blocks,
when used for a building or wall, should be placed with the bedding
horizontal. It is, further, the position in which the stone will stand
the greatest pressure.
Grindstones are made from an even-grained, rather friable sand-
stone, and are of different degrees of fineness, according to the work
to be done by them.
Hard siliceous sandstones and conglomerates, occurring in regions of
metainorphic rocks, are called " granular quartz," and quartzyte (p.435).
4. Sand-rock. — A rock made of sand, especially when not
of siliceous material. A calcareous sand-rock is made of cal-
careous sand ; it may be pulverized corals or shells, such as
forms and constitutes the beaches 011 shores off which living
corals and shells are abundant.
The beach sands become cemented below high- water mark into a
calcareous sand-rock, which consists of layers having the pitch of the
surface of the beach. They are often coarse, calcareous conglomerates.
5. Shale. — A soft, fragile, argillaceous rock, having an
uneven slaty structure. Shales are of gray, brown, black,
dull -greenish, purplish, reddish and other shades.
428 DESCRIPTIONS OF ROCKS-.
VARIETIES. — a. Bituminous shale, or Carbonaceous sliale (Brand*
schiefer of the Germans), impregnated with coaly material and yielding
mineral oil or related bituminous matters when heated, b. Alum shale;
impregnated with alum or pyrites, usually a crumbling rock. The
alum proceeds from the alteration of pyrite or the allied pyrrhotite
(p. 174).
6. Argillyte, or Phyllyte. — An argillaceous slaty rock,
like shale, but differing in breaking usually into thin and
even slates or slabs. Roofing and writing slates are exam-
ples. It is sometimes thick-laminated. Unlike shale, it
occurs in regions of metamorphic rocks, and often graduates
into hydromica, chloritic, and mica schists, and also, on
the other hand, into shale. Often called Clay-slate.
VARIETIES. — a. Bluish-black, b. Tile-red, c. Purplish, d. Grayish.
e. Greenish; f. Ferruginous, g. Pyritiferous. h. Thick-laminated;
affording thick slabs, instead of slates, i. Thick-bedded; a massive
rock, affording thick blocks or masses, j. Staurolitic. k. Ottr clitic.
Extensive quarries of slate exist in Vermont at Waterford. Thet-
ford, and Guilford, in the eastern slate range of the State ; in North-
field in the central range, and in Castleton and elsewhere in the
western range, the last of Lower Silurian age if not the others. There
are excellent quarries also in Maine and Pennsylvania. The rock fur-
nishes also thick slabs for various economical purposes. A trial as
to water absorption, and a clos'e examination as to the presence of
pyrite, is required before deciding that a slate rock is fit for use, how-
ever even its fissile structure. Kinds with a glossy surface are most
likely to be impervious to moisture.
7. Tufa. — A sand-rock or conglomerate made from com-
minuted volcanic or other igneous rocks, more or less altered.
Usually of a yellowish-brown, gray, or brown color, some-
times red.
VARIETIES. — a. Dolcrytic or basaltic; tufa made from those igneous
rocks that contain iron-bearing minerals, such as doleryte (trap), basalt,
and the heavier lavas ; it is usually yellowish-brown or brown in
color, sometimes red ; and often consists in part of palagonite (p. 312).
b. Trachytic; made of the f eldspathic igneous rock, trachyte, of an ash-
gray color, or of other light shades, c. Pumiceous ; made of frag-
ments of pumice. Pozzurtana- is a light-colored tufa, found in Italy.
near Borne, and elsewhere, and used for making hydraulic cement,
Wacke is an earthy brownish rock, resembling an earthy trap or dole-
ryte, usually made up of trappean or dolerytic material, compacted
into a rock that is rather soft.
8. Sand. Gravel. — Sand is comminuted rock-material ;
but common sand is usually comminuted quartz, or quartz
and feldspar, while gravel is the same mixed with pebbles
and stones. Sand often contains grains of magnetite, or
KINDS OF ROCKS. 429
of garnet, or of other hard minerals existing in the rocks of
the region. Occasionally magnetite or garnet is the chief
constituent.
Volcanic sand, or Peperino, is sand of volcanic origin,
either the "cinders" or "ashes" (comminuted lava),
formed by the process of ejection, or lava rocks otherwise
comminuted.
9. Green Sand. — An olive-green sand-rock, friable, or not
compacted, consisting largely of glauconite. See, for de-
scription and analysis, p. 307.
10. Clay. — Soft, impalpable, more or less plastic material,
chiefly aluminous in composition, white, gray, yellow, red
to brown in color, and sometimes black. It has been made
chiefly from the feldspars, by decomposition. See Kaolinite.
VARIETIES. — a. Kaolin, purest unctuous clay. b. Potter's day,
plastic, free from iron ; mostly unctuous ; usually containing some
free silica. Pipe-day is similar, c. Fire-brick day, the same ; but it
may contain some sand without injury, d. Ferruginous, ordinary
brick day, containing iron in the state of oxide or carbonate, and con-
sequently burning red, as in making red brick, e. Containing iron in
the state of silicate, and then failing to turn red on being burnt, as the
clay of which the Milwaukee brick are made. f. Alkaline and Vitri-
fidble, containing 2 '5 to 5 per cent, of potash, or potash and soda,
owing to the presence of undecomposed feldspar, and then not refrac-
tory enough for pottery or fire-brick, g. Marly, containing some car-
bonate of calcium, h. Weak clay, containing too much sand for brick-
making, i. Alum -bearing, containing aluminous sulphates, owing to
the decomposition of iron sulphides present, and hence used for mak-
ing alum.
The red pipestone of the North American Indians is an indurated
clayey rock^from the Coteau de Prairies ; it has been named Catlinite;
and the gray is in part compact argillyte.
11. Alluvium. Silt. Till. — Alluvium is the earthy deposit
made by running streams or lakes, especially during times
of flood. It constitutes the flats either side, and is usually in
thin layers, varying in fineness or coarseness, being the re-
sult of successive depositions.
Silt is the same material deposited in bays and harbors,
where it forms the muddy bottoms and shores.
LCBSS is a fine earthy deposit, following the courses of
valleys or streams, like" alluvium, but without division into
thin layers. Occurs in elevated plains, along the broad parts
of large valleys, as the Mississippi, Rhine, Danube.
Till is the unstratified sand, gravel, and stones, derived
from glaciers.
430 DESCRIPTIONS OF ROCKS.
Detritus (from the Latin for worn) is a general term ap-
plied to earth, sand, alluvium, silt, gravel, because the ma-
terial is derived, to a great extent, from the ivear of rocks
through decomposing agencies, mutual attrition in running
water, and other methods.
Soil is earthy material mixed with the results of vegeta-
ble and animal decomposition, whence it gets its dark color
and also a chief part of its fertility.
12. Tripolyte (Infusorial Earth).— Eesembles clay or chalk,
but is a little harsh between the fingers, and scratches glass
when rubbed on it. Consists chiefly of siliceous shells
of Diatoms with often the spicules of sponges. Forms
thick deposits, and is often found in old swamps beneath
the peat.
This soft diatomaceous material is sold in the shops under the name
of silex, electro-silicon, and polishing powder, and is obtained for com-
merce in Maine, Massachusetts, Nevada, and California. A bed ex-
ceeding fifty feet in thickness occurs near Monterey in California ; and
other large beds in Nevada near Virginia City, and elsewhere. It is
used as a polishing powder ; in the manufacture of "soluble glass;"
and also mixed with nitro-glycerine to make dynamite. Occurs some-
times slaty, as at Bilin, Prussia ; and also hard or indurated, from con-
solidation through infiltrating waters, and thus graduates, at times,
into chert. Consists of silica in the opal or soluble state.
II. Limestones or Calcareous Rocks.
1. NOT CRYSTALLINE.
1. Limestone. Calcyte — Compact uncrystalline limestone
usually of dull gray, bluish-gray, brownish, and black colors,
sometimes yellowish-white, cream-colored, nearly white,
and red of different shades ; in texture, varying from earthy
to compact semi-crystalline. It consists essentially of cal-
cite or calcium carbonate (p. 215), but often contains clay or
sand, or other impurities.
VARIETIES. — The varieties depending on color are very numerous,
and many of them, when pure and compact, are polished and used
for marble. The gray and black colors are due commonly to carbo-
naceous material, for they burn white ; but the yellow, red, and some
other kinds to the presence of iron, oxide. There are also : a. Fossil-
iferous or shell limestone, b. Coral or Madreporic limestone, c. En-
dinital or Crinoidal limestone; containing crinoidal remains in the
form mostly of small disks, d. Ntfmmulitic ; containing the disk-
shaped fossils called Nummulites. e. Oolitic limestone ; a limestone
having an oolitic texture, f. Bird's - eye limestone ; having small
whitish crystalline points scattered through it, a rock of Western
KINDS OF ROCKS. 431
New York, of the Trenton period in geology, g. Conglomerate lime-
stones.
The black marble of the United States comes mostly from Shore-
ham, Vermont, and other places in that State, near Lake Champlain,
and from near Plattsburg and Glenn's Falls, N. Y. ; also from Isle
La Motte. A pudding-stone marble, of various dull shades of color,
occurs on the banks of the Potomac, in Maryland, 50 or 00 miles above
Washington ; it is used for columns in the interior of the Capitol at
Washington.
The Portor is a Genoese marble very highly esteemed ; it is deep
black, with veinings of yellow ; the most beautiful comes from Porto-
Venese. The Nero-antico marble of the Italians is an ancient deep
black marble ; the paragone is a modern one, of a fine black color,
from Bergamo ; and panno di morte is another black marble with a
few white fossil shells.
A beautiful marble from Sienna, brocatello di Siena, has a yellow
color, with large irregular spots and veins of bluish-red or purplish.
The mandelato of the Italians is a light red marble, with yellowish-
white spots. The Madreporic marble is the Pietra stellaria of the
Italians.
Fire-marble, or lumachelle, is a dark brown shell marble, having
brilliant fire-like or chatoyant reflections from within.
Ruin marble is a yellowish marble, with brownish shadings or lines
arranged so as to represent castles, towers, or cities in ruins. These
markings proceed from infiltrated iron. It is an indurated calcareous
marl, and does not occur in large slabs.
Hydraulic limestone is a compact kind containing some clay, and
affording a quicklime the cement from which will set under water.
An analysis of a kind from Rondout, N. Y., afforded Carbonic acid
34-20, lime 25 50, magnesia 12 '35, silica 15 '37, alumina 9*13, iron
sesquioxide 2 '25. In making ordinary mortar, quartz sand is mixed
with pure quicklime and water, and the chemical combination is
mainly that between the water and lime, together with subsequently
an absorption of carbonic acid. With " hydraulic cement," silica and
alumina (that of the clay) are disseminated through the lime, and
hence these ingredients enter into chemical union with the lime and
water, and make a much firmer cement, and one which " sets " under
water.
Oil-bearing limestones occasionally occur. A kind used for build-
ing in Chicago, of the Niagara period, becomes spotted or streaked
with blackish mineral oil, after a few years' exposure to the weather.
Some of the pyramids of Egypt, including the largest, the pyra-
mid of Cheops, is made of nummulitic limestone ; and this is tLe
building material of Aleppo, the range of mountains between Aleppo
and Antioch being composed largely of this cream -colored rock.
A soft Tertiary limestone occurring in the vicinity of Paris has
afforded a vast amount of rock, of an agreeable pale yellowish color,
for fine buildings in Paris ; and a similar rock has long been used in
Marseilles, Montpellier, Bordeaux, Brussels, and other places in West-
ern Europe.
Most limestones have been made out of comminuted shells, corals,
and other like material ; and when of dark colors or black, it is usu-
ally owing to some carbonaceous matters present derived from the de«
4:33 DESCRIPTIONS OP ROCKS.
composition of the plants or animals of the waters in which they were
formed.
When burnt, limestone (CaO3C) becomes quicklime (CaO), through
loss of carbonic acid (C0a) ; and, at the same time, all carbonaceous
materials are burnt out, and the color, when it is owing solely to these,
becomes white.
2. Magnesian Limestone. Dolomyte, — Carbonate of calcium
and magnesium, but not distinguishable in color or texture
from ordinary limestone. The amount of magnesium car-
bonate afforded by analyses varies from a few per cent, to
that of true dolomite (p. 55).
Much of the common limestone of the United States is magnesian.
That of St. Croix, Wisconsin, the " Lower Magnesian/' afforded Owen
42 '43 per cent, of magnesium carbonate.
In some limestones the fossils are magnesian, while the rock is
common limestone. Thus, an Orthoceras, in the Trenton limestone of
Bytown, Canada (which is not magnesian), afforded T. S. Hunt, Cal-
cium carbonate 56 00, magnesium carbonate 37 '80, iron carbonate 5 95
=99-75. The pale-yellow veins in the Italian black marble, called
"Egyptian marble," and "portor" (see above), are dolomite, accord-
ing to Hunt ; and a limestone at Dudswell, Canada, is similar.
3. Chalk. — A white, earthy limestone, easily leaving a
trace on a board. Composition the same as that of ordi-
nary limestone.
4. Marl. — A clayey or earthy deposit containing a large
proportion of calcium carbonate — sometimes 40 to 50 per
cent. If the marl consists largely of shells or fragments
of shells, it is called /Shell-marl
Marl is used as a fertilizer ; and other beds of clay or sand that can
be so used are often in a popular way called marl. The "Green
sand " of New Jersey (p. 429) is of this kind.
5. Travertine. — A massive limestone, formed by deposi-
tion from calcareous springs or streams. The rock abounds
on the river Anio, near Tivoli, and St. Peter's at Rome is
constructed of it. The name is a corruption of Tiburtine.
It occurs in the Yellowstone Park, along Gardiner's River.
6. Stalagmite.— See page 216.
2. CRYSTALLINE LIMESTONE.
1. Granular or Crystalline Limestone (Marble). — Limestone
having a crystalline-granular texture, white to gray color, but
often of reddish and other tints from impurities. It is a
metamorphic rock ; it was originally common limestone ; it
became crystalline under the action of more or less heat ; in
KINDS OF ROCKS. 433
the process all the fossils present were obliterated, except
in some cases of partial metamorphism. Its impurities are
often mica or talc, trenwlite, white or gray pyroxene or scap-
olite ; sometimes serpentine, through combination with
which it passes into ophiolyte (p. 453) ; occasionally clion-
drodite, apatite, corundum.
VAKIETIES. — a. Statuary marble; pure white and fine grained,
b. Decorative and Architectural marble; coarse or fine, white, and
mottled of various colors, and, when good, free not only from iron in
the form of pyrite, but also from iron or manganese in the state of
carbonate with the calcium, and also from all accessory minerals, even
those not liable to alteration, and especially those of greater hardness
than the marble which would interfere with the polishing, c. Verd-
antique, or Ophiolyte. d. Micaceous, e. Tremolitic; contains bladed
crystallizations of the white variety of hornblende called tremolite.
f. Graphitic; contains graphite in iron-gray scales disseminated
through it. g. Chloritic; contains disseminated scales of chlorite,
h. Ghondroditic; contains disseminated chondrodite in large or smalt
yellow to brown grains.
White and grayish-white marble is abundant in Western New Eng-
land, and Southeastern New York (Westchester County). The tex-
ture is less coarsely crystalline in Vermont than in Massachusetts, the
crystallization of the limestone as well as of the associated schists in-
creasing in coarseness from the north to the south, or rather south-
southwest, which is the trend of the limestone belt. Fine marbles
are quarried in Dorset, West Rutland, Pittsford, and other places in
Vermont, and the best of statuary marble occurs abundantly in Pitts-
ford. The whitest marble of Rutland is not as firm as that mottled
with gray, owing apparently to the fact that it was made white by the
heat that crystallized it burning out any carbonaceous material ; while
at Pittsford, 16 miles to the north of Rutland, it is very firm, and is white,
probably, because it was made with less heat from a whiter lime-
stone. In Vermont, the best quarries occur where the strata stand
at a high angle : the layers in such regions were subjected to great
pressure in the upturning that gave them this position, and this pres-
sure has soldered many layers together in one that are separate where
the pressure was less ; consequently blocks as large as an ordinary
house might be obtained at some of the quarries. Good marble is also
quarried in Pennsylvania, Maryland, and Tennessee. One of the most
beautiful marbles from deposits of crystalline limestone in the United
States, is the mottled reddish-brown from East Tennessee, and mainly
from Knox and Hawkins counties. Another handsome marble is the
mottled red of Burlington, Vt., from the semi-crystalline Winooski
limestone ; and a still finer the deeper red (or cherry-red), mottled and
veined with white, of Swan ton, Vt., from the same limestone on the
northern borders of the State.
The Carrara marble of Italy, the Parian, of the island of Paros (the
birthplace of Phidias and Praxiteles), and the Pentelican, from quar-
ries near Athens, Greece, are examples of crystalline limestone. The
Carrara marble varies in quality from coarse to true statuary marble,
and the best comes from Monte Crestola, and Monte Sagro. Out of
434 DESCRIPTIONS OF ROCKS.
the 500 quarries only 20 furnish stone for the sculptor. The amount
of marble taken out from the quarries in 1876, was 120,000 tons,
valued at $2,400,000 ; and of this 40,000 tons came to the United
States. The Cipoliti marbles of Italy are white, or nearly so, with
shadings or zones of green talc.
2. Dolomyte. — Not distinguishable by the eye from gran-
ular limestone.
Part of the marbles above referred to are dolomyte. This is the
case with that of Westchester County, N Y. , that of Canaan, Con-
necticut, and of Lee and Stockbridge, Massachusetts.
II. Crystalline Rocks, exclusive of Limestones.
The crystalline rocks may be distributed according to
their composition into the following series or groups. Each,
excepting the first, embraces both metamorphic and eruptive
rocks.
1. Siliceous rocks. The kinds consisting mainly of quartz
or opal are here included. The first of those mentioned,
page 435, is intermediate between the f ragmen tal and meta-
morphic-crystalline rocks. The opal material is a chemical
deposit. The chert of sedimentary formations is believed
to be mainly tripolite consolidated through the solution of a
part of its material by the permeating waters and its sub-
sequent desposition — tripolite or diatom beds being made
chiefly of opal-silica which is readily soluble in waters
slightly alkaline.
2. The Mica and Potash-Feldspar series. These are emi-
nently alkali-yielding rocks, both the mica, whether mus-
covite, biotite, or lepidomelane, and the feldspar, whether
orthoclase or microcline, affording on analysis, as explained
on page 411, much potash, and the feldspars often also some
soda. The soda feldspar, albite or oligoclase, is a common
accessory ingredient. The series shades off into a rock
that is chiefly feldspar, and another that is chiefly mica ;
and in these two extremes the amount of potash yielded is
about the same. Moreover, as leucite is essentially a potash-
feldspar in ratio and composition (see page 411), rocks, con-
sisting chiefly of leucite, without pyroxene or hornblende,
belong with this series. Muscovite and biotite commonly
occur together, the formation of biotite having been deter-
mined by the presence of some iron oxide in the original
material from which it was made. The mica is sometimes
a hydrous species (page 313).
KINDS OF ROCKS.
3. The Mica and Soda-lime-Feldspar series. These grani-
toid rocks are equally alkali-yielding with those of the true
granite group, but the alkali is mainly soda. The nephelite
(elseolite) rocks not hornblendic are here included, although
they contain in general some microline or orthoclase.
4. The Hornblende and Potash-Feldspar series, or the Sye-
nyte group. In this series, the mica of the granite series is
replaced by the non-alkaline mineral, hornblende. Transi-
tions between the granite and syenyte rocks are common — a
bed that is true mica schist often becoming hornblendic ;
the same specimen may have mica and hornblende crystals
together, or parallel mica and hornblende layers, and then,
not far beyond the schist may be a purely hornblende rock ;
and so there are similar transitions in other parts of the
two series. This transition in a stratum of mica schist, a
metamorphic rock, indicates merely that the mud-bed or
sedimentary stratum, out of which the mica schist \^as
made, had a diminished proportion of alkali in some parts,
and, in still others, a complete absence of alkali — which is
just such a variation as might be looked for in oceanic sedi-
ments, as they spread over a wide region. The hornblende
may be replaced by epidote, another iron-bearing mineral.
5. The Hornblende and Soda-lime-Feldspar series. The
soda-lime-feldspars, in this series, may be either of the
triclinic species, from albite to anorthite.
6. The Pyroxene and Soda-lime-Feldspar series. The soda-
lime-feldspars are the same as in the preceding. Quartz
is very rarely present, except in traces. Potash replaces
soda in amphigenyte.
7. Pyroxene, Garnet, Epidote and Chrysolite rocks, con-
taining little or no Feldspar.
8. Hydrous Magnesian and Aluminous rocks,
&. Iron Ore rocks
1. SILICEOUS ROCKS.
1. Quartzyte, Granular Quartz. — A siliceous sandstone,
usually very firm, occurring in regions of metamorphic
rocks. It does not differ essentially from the harder sili-
ceous sandstones of other regions. Conglomerate beds are
sometimes included.
VARIETIES. — a. Massive, b. Schistose, c. Calcareous; sometimes
contains disseminated calcite which, where the rock is exposed to
weathering, is removed and leaves the rock loose in texture, or cellu-
436 DESCRIPTIONS OF ROCKS.
lar. d. Micaceous, e. Hydromicaceous ; it graduating at times into
hydromica or mica slate, f. Feldspathic, sometimes porpJiyritic (the
rock Arkose), or like granulite in its disseminated feldspar ; a coarsely
f eldspathic variety occurs north of Lenox, Mass. , and when it loses its
feldspar, it becomes cellular, like buhrstone ; at other places, as in
Cheshire, Savoy, and eastern Washington, Mass., the feldspar of a
feebly-consolidated quartzyte has been leached out by the tiltrating
waters, and the rock reduced thereby to sand, excellent for glass-mak-
ing, while in some localities the feldspar so removed has been made
into valuable beds of white kaolin, as in Brandon, Vermont, East Shef-
field, Mass., and elsewhere, g. Gneissoid ; containing some mica
and feldspar in layers, and so graduating toward gneiss, h. Andalu-
sitic ; containing andalusite, as in Mt. Kearsarge (Hitchcock), i. Tour-
malinic ; containing tourmaline. The vicinity of the great crystalline
limestone formation of the Green Mountain region, in Western New
England (in Vermont to the west of the principal ridge of the Green
Mountains), includes strata of quartzyts of great thickness, and high
summits in Bennington, and to the north, and also south, consist of it.
In several places the quartzyte strata graduate into, and also alternate
with, hydromica or mica slates, and in Massachusetts and Connecticut,
with gneiss. Between Bernardston, Mass., and Vernon, Vt., quartzyte
occurs in large beds, and also graduates into gneiss and hornblendic
rocks. Quartzyte exists also in the central part of the Southern New
Hampshire, in the Archaean area of Wisconsin, and in the Rocky
Mountain region, j. NovacuUtic-quartzyte, or Novaculyie (Whetstone).
Novaculyte is only in part an extremely fine-grained siliceous rock. Of
this nature is the variety from Whetstone or Hot Spring Ridge, in
Arkansas. This ridge, 250 feet in height above the Hot Spring Valley,
is made up of the beautiful rock, "equal," says D. D. Owen, "in
whiteness, closeness of texture, and subdued waxy lustre, to the most
compact forms and whitest varieties of Carrara marble. Yet it belongs
to the age of the millstone grit." Dr. Owen supposed it to have re-
ceived its impalpable fineness through the action of the hot waters on
sandstone. An analysis of the rock afforded him (Second Rep. Geol.
Arkansas, 1860, p. 24), Silica 98'0, alumina 0'8, potash 0'6, soda 05,
moisture, with traces of lime, magnesia and fluorine O'l = 100. He
states that alon^ the southern flank of the ridge there are over forty
hot springs, having a temperature of 100° F. to 148° F. Solid masses
from the fine rock have been got out weighing about 1,200 Ibs. ; the
coarser varieties are made into stones for bench tools.
Beds of quartzyte have been made, like those of sandstone, out of the
quartz grains of older rocks, no evidence, chemical or geological, favor-
ing the view that they could be, or have been, produced by chemical
deposition. Some quartzytes and sandstones have had part of the
grains converted into more or less perfect quartz crystals, from the de-
position about them of silica in the process of consolidation — the little
heat required for making the siliceous waters coming from the earth's
interior, as a consequence of thick accumulations of strata above, or
from the friction of upturning, or from warm springs.
2. Itaeolumyte. — Schistose, consisting of quartz grains with
some hydrous mica ; on account of the mica in the lamina-
tion, it is sometimes flexible, and is called flexible sandstone.
KINDS OF ROCKS*
437
Occurs in the gold regions of North Carolina and Brazil, and diamonds
are supposed to be sometimes connected as to origin with this rock.
3. Siliceous Slate.— Schistose, flinty, not distinctly granu-
lar in texture. Sometimes passes into mica slate or schist.
4. Chert. — An impure flint or hornstone occurring in
beds or nodules in some stratified rocks. It often resem-
bles fclsyte, but is infusible. Colors various. Sometimes
oolitic. Kinds containing iron oxide graduate into jasper
and clay ironstone ; and others, occurring as layers or no-
dules in limestone are whitish, owing to the limestone
material they contain. Chert sometimes contains cavities
which are lined with chalcedony or agate, or with quartz
crystals.
5. Jasper rock. — A flinty siliceous rock, of dull red, yel-
low, or green color, or some other dark shade, breaking with
a smooth surface like flint. It consists of quartz, with more
or less clay and iron oxide. The red contains the oxide in an
anhydrous state, the yellow in a hydrous ; on heating the
latter it turns red.
6. Buhrstone. — A cellular siliceous rock, flinty in texture.
Found mostly in connection with Tertiary rocks, and
formed apparently from the action of siliceous solutions on
preexisting fossil'iferous beds, the solutions removing the
fossils and leaving cavities.
Buhrstone is the material preferred for millstones. The buhrstone
of the vicinity of Paris, France, has long been largely exported for
this purpose. Good buhrstone is obtained also from the Tertiary in
Greenville District, South Carolina, 100 miles up the Savannah River.
7. Fioryte. (Siliceous Sinter, Pearl Sinter, Geyserite.) —
Opal-silica, in compact, porous, or concretionary forms,
often pearly in lustre ; made by deposition from hot sili-
ceous waters, as about geysers (Geyserite), or through
the decomposition of siliceous minerals, especially about
the f umaroles of volcanic regions.
Geyserite is abundant in Yellowstone Park, and about the Iceland
geysers ; after long exposure it crumbles down and becomes changed
to ordinary silica, or quartz.
2. MICA AND POTASH-FELDSPAR SERIES.
1. Granite. — Consists of quartz, orthoclase, and mica, and
has no appearance of layers in the arrangement of the mica
or other ingredients. G. = 2'5-2'8. The quartz is usually
grayish-white or smoky, glassy, and without any appearance
438 DESCRIPTIONS OF ROCKS.
of cleavage. The feldspar is commonly whitish or flesh-
colored, and may be distinguished from the quartz by its
cleavage surfaces, which reflect light brilliantly when the
specimen is held in the sunlight. The mica is usually in
small bright scales, either silvery, brownish-black, or black
in color, and the point of a knife carefully used will easily
split them into thinner scales ; the silvery mica is muscovite,
but sometimes of the allied hydrous kinds, margarodite or
damourite, and the black mica is usually biotite, though
occasionally the allied, more iron-bearing, species, lepidome-
lane. Oligoclase or albite is very often present.
Occurs both metamorphic and eruptive. Metamorphic
granite may often be seen graduating into gneiss, or lying
in beds alternating with gneiss.
VARIETIES. — There are, A. Muscovite granites ; B. Biotite granites ;
C. Muscovite-and-biotite granites, the last much the most common.
The most of the following varieties occur under each except the horn-
blendic, which is usually a Biotite, or Muscovite-and-Biotite, granite.
There is also, D. Hydromica-granite. a. Common or Ordinary granite ;
the color is grayish or flesh-colored, according as the feldspar is white
or reddish, and dark gray when much black mica is present. Granite
varies in texture from fine and even, to coarse ; and sometimes the
mica, feldspar, and quartz — especially the two former — are in large
crystalline masses. An average granite (mean of 11 analyses of Lein-
ster granite, by Haughton) affords Silica 72*07, alumina 14'81, iron
protoxide and sesquioxide 2'52, lime 1*63, magnesia 0'33, potash 5'11,
soda 2-79, water 1-09=100-35. b. Porphyritic granite; has the ortho-
clase in defined crystals, and may be (a) small porphyritic, or (ft) large
porphyritic, and have the base (y) coarse granular, or (6) fine, and
even subaphanitic. c. Albitic granite; contains some albite, which is
usually white, d. Oligoclase granite (Miarolite) ; contains much oligo-
clase. e. Microcline granite ; contains the potash triclinic feldspar,
microcline. f. Hornblendic granite; contains black or greenish-black
hornblende, along with the other constituents of granite, g. Black
micaceous granite ; consists largely of mica, with defined crystals
of feldspar (porphyritic), and but little quartz, h. lolitic ; con-
taining iolite. i. Globuliferous granite; contains concretions which
consist of mica, or of feldspar and mica. j. Oneissoid granite; a
granite in which there are traces of stratification; graduates into
gneiss, k. Pegmatyte, or Graphic granite ; consists mainly of ortho*
clase and quartz, with but little mica ; but the quartz is distributed
through the feldspar in forms looking like oriental characters.
A porphyritic granite, occurring at the junction of the andalusite
mica-argillyte (page 441) of the White Mountain Notch, N. H., with
the Mt. Willard granite, on the west side of Mt. Willard, conformable
with the bedding of the argillyte, has the argillyte for its base ; and
in it the orthoclase is in large well-defined crystals, and the quartz
in double six-sided pyramids, both easily separable from the matrix ;
the layer is six to twenty feet thick.
KINDS OF ROCK. 439
The distinctions as to kinds of rocks between metamorphic and
eruptive granites are not yet made out. A porphyritic variety, having
the base fine-grained, occurs east of Parkview Peak, in the Rocky Mts.,
which, according to Hague, is eruptive and related to the trachytes of
the region. The granite of New England is for the most part meta-
morphic or in veins. The following are prominent regions of the
granite quarries. In Maine : at Hallo well, a whitish granite, some-
times a little gneissoid ; at Rockport, whitish ; at Clarke's Island,
spotted gray ; at Jonesbury, flesh-red ; also in the Mt. Desert region!
In New Hampshire, at various places, but most prominently near Con-
cord, a fine-grained whitish granite. In Massachusetts at several
points, especially in Gloucester at Rockport, a red granite. (The Quincy
"granite" is a syenyte.) In Rhode Island, at Westerly, a fine-grained
whitish granite. In Connecticut, at Millstone Point near Niantic, and
at Groton, near New London, a fine-grained whitish granite ; at Stoney
Creek, a pale reddish, but liable to large micaceous spots ; at Ply-
mouth, on the Naugatuck, a whitish granite, even and fine-grained,
more easily worked than the Westerly.
2. Granulyte. (Leptinyte.) — Like granite, but containing
no mica, or only traces. Metamorphic and eruptive.
VABIETIES. — a. Common granulyte ; white and usually fine granu-
lar, a common rock in Western Connecticut and West Chester Co., New
York. b. Flesh-colored; usually coarsely crystalline, granular, and
flesh-colored; the coarse flesh- colored "granite" of the Eastern or
Front Range of the Rocky Mts. , in Colorado, sometimes called Aplite,
is partly of this kind ; it contains a little albite or oligoclase with the
orthoclase. c. Garnetiferous. d. Hornblendic ; containing a little
hornblende — a variety that graduates into syenyte. e. Magnctitic ;
containing disseminated grains of magnetite, a kind common in
Archaean regions, in the vicinity of the iron ore beds, occurring in
Orange Co., N. Y., and south in New Jersey, and also at Brewster's,
Dutchess Co., N. Y., and in Kent and Cornwall, Conn. f. Graphic
(Pegmatyte) ; like gr. Ajhic granite, but containing no mica. The
coarser granulyte, especially that of veins, is often called pegmatyte
when not graphic.
3. Gneiss. — Like granite, but with the mica and other
ingredients more or less distinctly in layers. Gneiss breaks
most readily in the direction of the mica layers, and hence
its schistose structure ; in consequence of this structure,
many kinds may be got out in slabs. It often graduates
imperceptibly into granite. Metamorphic. •
VARIETIES.— Similar to those under granite, a. Porpliyritic. b Al-
Utic c Oligodase-bearing. d. Hornblendic. e. Micaceous, f. Crloou-
UProiis. g. Epidotic. h. Garnetiferous. i. Andalusitic; contains an-
dalusite in disseminated crystals, j. Cyanitic ; contains cyanite, a
variety that has been observed on New York Island, and also in New,
town Ct. Bellows Falls and elsewhere in N. H. k. Graphitic; con-
tains graphite disseminated through it. 1. Quartzose ; the quartz
largely in excess, m. Quartzytic ; consists largely of quartz in grams,
being intermediate between quartzyte and gneiss, a variety occurring
just northeast of Bernardstou, Mass. Fig. 3 on page 415 represents,
440 DESCRIPTIONS OF ROCKS.
natural size, a small pioce of the porphyritic gneiss of Birmingham,
Conn.
Some gneiss is very little schistose, being in thick, heavy beds,
granite-like, while other kinds, especially those containing much
mica, are thin-bedded, and very schistose ; the latter graduate into
mica schist. The so-called granite of Monson, Mass., is a granitoid
gneiss. Its gneissoid structure facilitates greatly the quarrying.
4. Protogine. Protogiae-gneiss. — Coarse to fine granular,
granite-like or gneissoid in structure, and mostly the lat-
ter ; of a grayish-white to greenish-gray color ; consists of
quartz, white or grayish- white, rarely flesh-red, orthoclase,
a dark green mica and often chlorite, with some greenish-
white talc, and white oligoclase. Metamorphic.
The dark green mica approaches chlorite, as shown by Delesse, in
its very large percentage of iron oxide (Fe20321'31, FeO5 03), but it
gave him only 0 90 of water, with 6 '05 of potash. Among accessory
minerals are hornblende, titanite, garnet, serpentine, magnetite. In
an analysis of the protogine as a whole, Delesse obtained Silica 74-25,
alumina 11'58, iron oxide 2'41, lime 1'OS, water 0-97, leaving 10*01 for
potash, soda and magnesia. From the region of Mont Blanc and
other parts of the Swiss Alps.
5. Mica Schist. — Consists largely of mica, with usually
much quartz, some feldspar, and, on account of the mifti,
divides easily into slahs, that is, is very schistose. Usually
both of the potash micas, muscovite and biotite, are present,
and the latter (black mica) is commonly much the most
abundant. The colors vary from silvery to black, according
to the mica present. Often crumbles easily; and roadsides
are sometimes spangled with the mica scales. The dissemi-
nated scales or crystals of biotite are sometimes set trans-
versely to the bedding. Metamorphic.
VARIETIES. — a. Gneissoid ; between mica schist and gneiss, and
containing much feldspar, the two rocks shading into one another.
b. Hornblendic. c. Garnetiferous. d. Staurolitic. e. Cyanitic. f. An-
dalusitic. g. Fibrolitic ; containing fibrolite. h. Tourmalinic. i. Cal-
careous ; limestone occurring in it in occasional beds or masses.
j. Graphitic, or Plumbaginous ; the graphite being either in scales or
impregnating generally the schist, k. Quartzose; consisting largely of
quartz. 1. Quartzytic ; a quartzyte with more or less mica, rendering
it schistose, m. Specular, or ltdbyrite ; containing much hematite or
specular iron in bright metallic lamellae or scales. In fine-grained
mica schist, the scales of mica tire sometimes scarcely visible without
a lens.
6. Hydro-mica Schist. — A thin-schistose rock, consisting
either chiefly of hydrous mica, or of this mica with more
or less quartz. ; having the surface nearly smooth, and
KINDS OF ROCKS. 441
feeling greasy to the fingers ; pearly to faintly glistening in
lustre ; whitish, grayish, pale greenish in color, and also of
darker shades. For analyses of hydrous micas see page 313.
Metamorphic.
This rock used to be called talcose slate, but, as first shown by Dr. C.
Dewey, it contains no talc. It includes Parophite schist, Damourite
slate and Sericite slate (Glanz-Schiefer and Sericit-Schiefer of the Ger-
mans.)
VARIETIES.— a. Ordinary ; more or less silvery in lustre, b. Chlo-
ritic ; contains chlorite, or is mixed with chlorite slate, and has there-
fore spots of olive-green color; graduates into chlorite slate, c. Gar-
netiferous. d. Pyritifcrous ; contains pyrite in disseminated grains or
crystals, e. Mugnetitie ; contains disseminated magnetite, f . Quart-
zytic; consists largely of quartzyte, or is a quartzyte rendered schistose
and partly pearly by the presence of hydrous mica, as is well seen in a
ridge northeast of Rutland, Vermont, which consists partly of quartzyte
and partly of hydromica schist.
7. Paragonite Schist. — Consists largely of the hydrous
soda mica called paragonite (p. 314); but in other characters
resembles hydromica schist. Metamorphic.
8. Minette. — Brown to black, fine-grained, compact, not
distinctly schistose ; consisting of biotite (according to
the description and analysis of Delesse) and orthoclase ;
contains also a little hornblende. Occurs in beds in the
Vosges, France, associated with granite, syenytc, and other
crystalline rocks. Sometimes feebly porphyritic and small-
concretionary, the concretions consisting mainly of ortho-
clase. Made eruptive by Delesse, and metamorphic by some
later authors. Approaches argillyte in aspect.
9. Greisen. — Massive, without schistose structure. A mix-
ture of granular quartz and mica, in scales. The mica may
be muscovite, lepidolite, or biotite. It is a granite with the
feldspar left out, and occurs in regions of gneiss, granite,
or quartz vte, and sometimes graduates into these rocks.
Metamorphic.
Occurs in characteristic form at Zinnwald, in the Erzgebirge, where
it sometimes contains tin ore as an accessory ingredient, and is fre-
quently penetrated by veins of tin ; also in the tin ore regions of
Schlackenwald and Cornwall. Occurs in the region of quartzyte, horn-
blendic rocks and gneiss, of Upper Silurian age, between Bernards-
ton, Mass , and Vernon, Vt., within three miles northeast of the former
place, and also near Vernon ; but at this place it contains usually a
little hornblende, making it a very tough rock, and is intermediate
between the quartzyte, homblendic rock and mica schist of the region.
10. Mica- Argillyte or Mica-Phyllyte. — Includes the part of
argillyte (p. 428) which has the composition nearly of a hy-
drous mica, like that of the White Mountain Notch, where
442 DESCRIPTIONS OF ROCKS.
much of it is andalusitic. Analysis of this White Mountain
rock, by Hawes, afforded Silica 46*01, alumina 30'56, iron
sesquioxide 1*44, iron protoxide 6*85, manganese protoxide
0*10, magnesia 1*42, soda 1*12, potash 6 '66, titanium dioxide
1*91, water 4*13 = 100-22. (Compare with analyses of hy-
drous muscovite, or margarodite.) Metamorphic.
11. Felsyte. Quartz-Felsyte. (Euryte, Petrosilex.) — Com-
pact orthoclase, with often some quartz intimately mixed;
fine granular to flint-like in fracture; sometimes contains
oligoclase. Colors white, grayish-white, red, brownish-red
to black. G.^2'6-2'7. Both metamorphic and eruptive.
VAEIETIES. — There are two sections, I. Felsyte, and II. Quartz-
Felsyte, and under each occur the following varieties, a. Porphyritic
FeUyte, or Porphyry ; containing the feldspar in small crystals distri-
buted through the compact base ; color red and of other shades ; called
sometimes Quartz-porphyry, when the base is a quartz-felsyte. b. Con-
glomerate fclsyte ; containing pebbles, as at Marblehead, Mass., and in
the White Mountains, c. OUyoclase-bearing ; containing this triclinic
feldspar intimately blended with the orthoclase. d. Cellular or amyg-
daloidal. e. Elvanyte ; essentially a quartzose felsyte, of gray, bluish-
gray to brown and red colors, and often containing disseminated grains
or crystals of quarfcz and feldspar, and some oligoclase ; some compact
slate-rock has the sams composition. Occurs in Cornwall.
The metamorphic and eruptive kinds are not easily distinguished.
The former occurs associated with sedimentary strata, and often con-
tains pebbles or other evidence of fragmental origin ; while the lat-
ter is frequently in dikes, that is, fills the fissures through which it
was ejected. Some of the eruptive felsyte has nearly the aspect of
trachyte, with which rock it is identical in composition. Much of the
red porphyry contains hornblende with the feldspar of the base, and
has the constitution of dioryte (p. 447).
12. Porcelanyte. (Porcelain Jasper.)— A baked clay, hav-
ing the fracture of flint, and a gray to red color; it is some-
what fusible before the blowpipe, and thus differs from
jasper. Formed by the baking of clay-beds, when they con-
sist largely of feldspar. Such clay-beds are sometimes baked
to a distance of thirty or forty rods from a trap dike, and
over large surfaces by burning coal beds. Metamorphic.
13. Trachyte. Quartz-Trachyte. — Consists mainly of feld-
spar, which is partly in glassy crystals, either sanidin or
oligoclase ; and, owing to the angular forms of the glassy
feldspar and the porosity of the rock, the surface of frac-
ture is rough, whence the name from the Greek trachus,
rough. Sometimes contains disseminated quartz, and is
then quartz-trachyte. Color ash-gray, greenish-gray, brown-
ish-gray, but sometimes yellowish and reddish. G. =2'5-
2*7. Besides the feldspar there are distributed, somewhat
KINDS OF ROCKS. 443
sparingly, through the mass, in many kinds, minute needles
of hornblende, crystals or scales of biotite, magnetite ; some-
times nephelite, haiiynite, tridymite. Apatite exists in the
rock in microscopic forms, and there is also more or less of
the rock in a glassy state. Sometimes contains augite, and
has a higher specific gravity. Quartz-trachyte has often
nearly the composition of granite in which there is little
mica. Eruptive only.
VARIETIES. — The two principal divisions under each, trachyte and
quartz-trachyte, are : A. Kanidin-trachyte, in which the mass is chiefly
sanidin ; and B. Oliyodasc-trachyte, or Domyte, in which it is partly
oligoclase ; but the two graduate into one another. Both occur por-
pliyritic with tabular crystals of feldspar ; and in the latter (as at
the Drachenfels) the tables are sanidin. They graduate into vesicular
or scoriaceous trachyte.
Trachyte, according to Reyer and Suess, occurs in the region of the
Euganean Hills of Tertiary, Cretaceous and Jurassic age ; and the
f elsyte of Paleozoic age is often hardly distinguishable from it, while
identical with it in composition.
Trachyte and quartz-trachyte, graduate also into felsyte-like volcanic
rocks of like constitution, porphyritic or not so. The latter sometimes
shades into rocks of semi-glassy nature called
14. Pearlstone, when somewhat pearly in lustre; PITCHSTOXE
when having a pitch-like lustre; and these into the glassy
volcanic material called Obsidian. These glassy rocks often
contain spherules which are concretions consisting of feld-
spar with some quartz. Pumice is a light, porous, feldspa-
thic scoria, with the pores capillary and parallel. Ordina-
ry obsidian, that consists chiefly of feldspar, and is hence
nearly free from iron, belongs here; the rest of it belonging
with the augitic igneous rocks.
15. Leucityte. — A grayish rock consisting chiefly of leucite
in a felsitic state, with disseminated leucite crystals. Occurs
at Point of Rocks, Wyoming Territory, according to King
and Zirkel. It differs" from amphigenyte, in containing no
pyroxene, or only traces of it.
3. MICA AND SODA-LIME-FELDSPAR ROCKS.
I. NOT CONTAINING NEPHELITE.
1. Hemi-dioryte. (Mica-dioryte, Soda-granite.)— A gran-
ite-like rock, in which the feldspar is chiefly oligoclase ; it
contains much biotite, with usually some quartz, and often
some hornblende. Occurs at Stony Point, on the Hudson,
444 DESCRIPTIONS OF ROCKS.
and near Cruger's, in the town of Cortland, N. Y., at the
latter place often graduating into a granite-like dioryte.
Kersantyte is described by Delesse as consisting of biotite and oligo-
clase, with some quartz, frequently hornblende in needles, and mag-
netite ; from the Vosges, the Saxon Erzgebirge, and Nassau. Kersan-
ion is a similar rock, containing no hornblende, from near Brest, and
from Quimper, in Brittany. Both of these rocks have been called mica-
dioryte.
Kinzigyte^ is a compact and schistose granular-crystalline rock, con-
sisting of biotite, oligoclase, and garnet, without quartz, and contain-
ing, as accessory, microcline, iolite and fibrolite ; from Kinzig, north
part of Black Forest.
II. CONTAINING NEPHELITE.
1. Miascyte. — Granitoid to schistose, and consisting of
microcline, massive nephelite (elaeolite), sodalite, biotite,
along with some quartz, and often some zircon, pyrochlore,
monazite and other minerals. A related nephelite rock oc-
curs on Pic Island, Lake Superior. Named by G. Rose,
from Miask in the Ilmen Mountains, where it has a wide
distribution. Metamorphic.
2. Ditroyte. — A coarse to fine-grained rock, consisting of
microcline, nephelite (elasolite), and sodalite. From Ditro in
Eastern Transylvania, where it is associated with syenyte
and mica schist and lies between these two rocks.
3. Phonolyte. (Clinkstone.) — Compact; of grayish, blue,
and other shades of color ; more or less schistose or slaty in
structure; tough, and usually clinking under the hammer,
like metal, when struck, whence the name. G.=2vk-2'7.
Consists of glassy feldspar (orthoclase or oligoclase), with
nephelite and some hornblende. G. Jenzsch gives, for the
composition of the Bohemian phonolyte, Sanidin (glassy or-
thoclase) 53-55, nephelite 3T76, hornblende 9-34, sphene 3-67,
pyrite 0-04=98*36. Under treatment with acids the nephe-
lite is dissolved out. Nosean and hauynite occur in some
phonolyte. Eruptive only.
4. HORNBLENDE AND POTASH-FELDSPAR SERIES.
In this series the hornblende is sometimes replaced by
epidote, another anhydrous iron-bearing mineral, yielding
on analysis little or 110 alkali ; microcline is often present
as well as orthoclase. The species graduate into kinds con-
sisting almost solely of hornblende. Biotite is often pres-
ent as an accessory mineral.
KINDS OF ROCKS. 445
I. NOT CONTAINING NEPHELITE.
1. Syenyte. Quartz-Syenyte, — A granitoid rock consisting of
hornblende and orthoclase, with or without quartz. Oligo-
clase and biotite are often present. The quartziferous va-
riety, or qudrtz-syenyte, includes the syenyte of the obe-
lisks and pyramids of Egypt. Like that, the rock is often
flesh-colored ; but whitish and grayish varieties are also
common. The Saxon syenyte, without quartz, afforded
Silica 59*83, alumina 16*85, iron protoxide 7*01, lime 4*43,
magnesia 2'61, potash 6*57, soda 2*44, water 1*29, and Gr. =
2- 75-2 -90. Metamorphic and eruptive. Similar varieties
occur under both divisions of syenyte.
VAEIETIES. — a. Porphyritic. b. AlUtic ; containing albite in addi-
tion to the constituents of true syenyte. c. Oligodase-bcaring. d. Mi-
caceous ; containing disseminated black mica, which is usually bio-
tite, and sometimes lepidomelane. e. Garnetiferous. f. Epidotic /
containing disseminated epidote. The gray " granite " of Quincy,
Massachusetts, south of Boston, extensively quarried for architectural
piirposes, is a quartz-syenyte, consisting of orthoclase, black to dark
green hornblende, and quartz, with some triclinic feldspar. Quartz-
syenyte occurs also in the Frankenstein Cliff, five miles south of
White Mountain Notch ; also in Mount Chocorua, N. H. ; in the Ar-
chaean of Canada, at Grenville, a red kind containing very little quartz,
and a similar rock on Barrow Island, St. Lawrence, but containing
much quartz and little hornblende. Syenyte without quartz is a rare
rock in Eastern North America. It occurs in Nevada.
The name Syenites is used for this rock by Pliny, who adds that it
was also called " pyrrhopoecilon"— this appellation, meaning fire-red
variegated, referring to its being brightly spotted with rose-red. The
quarries in the vicinity of Syene (the modern Assouan), whence the
Egyptians obtained this stone for their obelisks, columns, statues,
sphinxes, sarcophagi, and the lining of their pyramids, are of great
extent ; and in one of them there is an unfinished obelisk in its origi-
nal position. They are situated to the south of Syene, and between
that place and the island of Philoe. The rock consists chiefly of red
feldspar and grayish quartz, with oligoclase, some black hornblende,
and a little black mica. An analysis by Delesse obtained Silica
70 '25, alumina 16 00, iron oxide with some manganese 2 '50, lime 1'GO,
expelled on ignition 4'65, magnesia and alkalies by loss 9 00=100.
More remote from Syene the rock loses its hornblende and becomes
a granite.
The Scotch syenyte, so much used for monuments, is quartz-syenyte.
It occurs both red and dark gray, and the former is closely like the
Egyptian syenyte.
Werner applied the name " syenyte " to the quartzless syenyte of
Plauen.schen- Grunde, Saxony, an analysis of which is given above (a
rock he afterwards called "greenstone"). G. Rose used the term for
the quartz-syenyte. Other German lithologists have followed Werner,
calling the quartz-syenyte, hornblende-granite. It seems best to draw
446 DESCRIPTIONS OF ROCKS.
the line between the mica-bearing and the hornblende-bearing rocks,
as here done, and to use the name syenyte for the rock to which it was
originally applied, as well as for the quartzless kinds.
2. Syenyte-gneiss. — Like gneiss in aspect and schistose
structure ; and also in constitution, except that horn-
blende replaces mica. Occurs both with and without
quartz, though usually quartz-bearing. The varieties are
nearly the same as under syenyte. Metamorphic.
3. Hornblende schist. — A schistose rock consisting of horn-
blende, with usually more or less quartz, but sometimes
almost wholly hornblende. Frequently contains epidote,
garnet, magnetite. Metamorphic.
4. Amphibolyte or Hornblendyte,— A tough, granular-crys-
talline rock, consisting of hornblende, and hardly schistose
in structure. Color, greenish-black to black. Metamorphic.
A Glaucophanitic. variety consists chiefly of the blue soda-hornblende,
called glaucophane, with usually some black mica ; from Saxony, Isle
of Syra, New Caledonia. A cTirysolitic variety occurs at Stony Point,
Rockland Co., N. Y., and on the opposite side of the Hudson River,
north of Cruger's.
5. Actinolyte. — A tough, massive rock made chiefly of
actinolite. Grayish green. Metamorphic.
6. Unakyte. — A flesh-colored granitoid rock consisting of
orthoclase, quartz, and much yellowish-green epidote. From
the Unaka Mountains, North Carolina, and East Tennessee.
II. CONTAINING NEPHELITE.
1. Zircon-Syenyte. — A crystalline granular rock consisting
of orthoclase, microcline, little hornblende, crystals of zir-
con, and some elseolite.
2. Foyayte.— Coarse crystalline, granular to compact ;
consists of orthoclase, reddish-brown nephelite (eloeolite), in
six-sided prisms, and blackish-green hornblende. Occurs
alsoporphyritic, and passes into an aphanitic variety. From
Mt. Foya and Picota, in the Province Algarve, in Portugal.
Ditroyte (p. 444) is related, but contains very little horn-
blende.
5. HORNBLENDE AND SODA-LIME-FELDSPAR SERIES.
I. NOT CONTAINING SAUSSURITE IN PLACE OF THE
FELDSPAR CONSTITUENTS.
1. Dioryte. Quartz-Dioryte. ( Greenstone in part. )— The
triclinic feldspar, one of the acidic (rich in silica) species,
KINDS OF HOCKS. 447
albite or oligoclase. Texture granitoid to fine-grained or
compact. Color often grayish-white to greenish-white for
the coarser kinds ; olive-green to blackish-green for the
finer. Very tongh. G. =2-7-3 '0. The quartz-bearing and
quartz-less kinds constitute two sections having similar va-
rieties. Dark-red, brownish-red, and dark-green porphy
ritic kinds, compact in base, have been called porpliyryte.
Metamorphic and eruptive.
VARIETIES. — a. Granitoid; granite-like in texture, b. Compact
or fine-grained, with the feldspar grains scarcely distinguishable.
c. Porphyritic ; the feldspar in crystals in a compact base. d. Slaty ;
a dioryte slate or schist, usually chloritic. e. Micaceous, f. Apha-
nitic (or Aphanite) ; nearly flint-like in texture.
An analysis of a dioryte of the Hartz afforded Silica 54'65, alumina
15 "72, iron sesquioxide 2 '00, iron protoxide 6 '26, manganese protoxide
trace, magnesia 5 '91, lime 7'83, potash 3'79, soda2'90, water and ig-
nition 1-90 = 100-96.
The antique red porphyry, or "rosso antico," figured on page 415,
is an example of porphyritic dioryte. The crystals, according to the
analysis of Delesse, are oligoclase, and have G. =2'67, while the base
has G.=2'765, it consisting of an intimate mixture of oligoclase and
hornblende, with some grains of iron oxide. For the whole mass, accord-
ing to Delesse, G. =2.703, but after fusion, only 2 '486. Distinct acicu-
lar crystals of hornblende occur in it. The rock is sometimes a brec-
cia, being made up of angular fragments, either quite distinct from the
mass or else shading off into it, but all alike porphyritic. The Mt.
Dokhan, in which it occurs — " Porphyrites mons" of Ptolemy — con-
tains also red syenyte similar to that of Syene, and a coarse red gran-
ite. The "porphyrite" of Ilfeld, of Schonau in Bohemia, and the
" quartz -porphy rite" of Koliwansk in the Altai are here referred.
Propylyte and quartz-propylyte have 'the same constitution. The
former is the prevailing igneous rock of the Washoe district (vicinity
of the Comstock lode), in Nevada ; it is a grayish-green rock, yield-
ing, on analysis, 64 to 66 per cent, of silica, and containing, along
with oligoclase, hornblende, disseminated in minute points, and rarely
alsobiotite (Zirkel).
Ophite, of the Pyrenees, is greenish black dioryte.
2. Andesyte. Quartz- Andesyte. — Contains the feldspar an-
desite along with hornblende. As in the preceding, the
hornblende' is sometimes changed to chlorite. Quartz-an-
desyte, or Dacyte, is a quartz-bearing variety. Both kinds
occur in the Washoe district, Eruptive. Also metamorphie?
Banatite and Tonalite are like quartz-dioryte in most characters,
but have the feldspar the species andesite. Each contains some bio-
tite, the latter much of it. Banatite is from the Banat, and Tonalite
from near Tonal e, in the Southern Alps.
Trachydoleryte (of Abich\ a dark gray to reddish-brown rock, some-
what trachyte-like in aspect, is, in part, near andesyte, it consisting of
448 DESCRIPTIONS OF HOCKS.
oligoclase or andesite and hornblende, with G.— 2 73 — 2*80, and afford-
ing 55 to 01 per cent, of silica ; it occurs in the Peak of Teneriffe, on
Liscanera I. near Stromboli, and on some parts of Etna. Another rock
included under this name, found at Stromboli, Rocca Monfina, and
Tunguragua in Quito, contains augite in place of hornblende, with
oligoclase or labradorite, and is near doleryte. A third rock described
under this name by Ludwig is augitic trachyte, the feldspar being
sanidin. Trachyte graduates into andesyte, augite -andesyte, doleryte,
as well as granite.
3. Labradioryte. (Labradorite-Dioryte, Greenstone in part.)
—The feldspar one of the basic (poor in silica) species, la-
bradorite or anorthite. Texture usually fine-grained, some-
times crypto-crystalline. Color light grayish-green to dark
olive-green, blackish-green or gray, and sometimes black.
Very tough. G. =2 -8-3*1. Often contains chlorite and
magnetite. Often has associated with it beds of serpentine
or ophiolyte. Metamorphic and eruptive.
VABIETIES. — a. Granular crystalline, b. Compact, or fine-grained ;
of dark green color ; constituent minerals not distinct, c. Porphyri-
tic ; the feldspar in whitish or greenish- white crystals disseminated
through a fine-grained bass, making a greenish "porphyry;" its
crystals sometimes anorthite. d. Pyroxcnic ; containing some dissem-
inated pyroxene, e. Magnetitic ; containing magnetite or titanic iron.
Occurs in the Urals ; to the west of New Haven, Conn., both massive
and porphyritic ; in Littleton, N. H. A porphyritic variety of the
rock near New Baven— a metamorphic rock— afforded Hawes, Silica
pact non-porphyritic variety from the same formation, collected on
Stoeckel's farm, afforded Hawes, Silica 50'36, alumina 14'57, iron ses^
quioxide 2'48, iron protoxide 8'31, manganese protoxide 0'46, magne-
sia 7-62, lime 11-13, soda 3'04, potash 0 44, water 0'78, titanium diox-
ide 1'70, chromium oxide 0'78— 100*89 ; G.=3'04. The crystals of the
porphyritic variety, according to an imperfect analysis by E. S. Dana,
consist of anorthite.
4. Corsyte. — A granitoid rock, consisting chiefly of anor-
thite and hornblende, with some quartz and biotite. From
Corsica.
Teschenite is bluish-green, and chiefly consists of anor-
thite, hornblende, and augite, the hornble de sometimes in
large black prisms ; also contains analcite. From Teschen,
Austria.
5. Isenite. — Contains a triclinic feldspar and hornblende,
with much nephelite and nosean, and some magnetite.
From the Eisbach (Isena) district in the Westerwafd, West
Germany.
KINDS OF ROCKS. 449
II. SAUSSURITE-BEARING.
6. Euphotide. (Gabbro in part.) — A grayish-white to gray-
ish-green, and sometimes olive-green rock, very tough, having
G. =2*9-3 €4. Consists of saussurite of whitish to greenish
and bluish color, mixed either with smaragdite of emerald-
green color, or with green to grayish-green diallage ; the
diallage generally containing more or less hornblende, and
the smaragdite, pyroxene. The saussurite is commonly of
either the first or second kind mentioned on page 410 ; but
the distribution of these kinds is not fully made out. Labra-
dorite is rarely present locally in place of the saussurite.
Metamorphic.
VARIETIES. — a. Diallagic; diallage the chief foliated mineral, b.
Smaragditic ; emerald-green smaragdite, the foliated mineral, c. Mi-
caceous ; contains mica. d. Serpentinous ; contains some serpentine —
a rock into which it often graduates, e. Garnetiferous. f . /Schistose ;
especially so when talc is present, g. Variolitic ; contains aphani-
tic concretionary spheroids of the saussurite mineral, as in the " Vario-
lite de la Durance," and of Mt. Genevre, and asociated with ordinary
euphotide ; for which concretions Delesse obtained the composition
Silica 56 '12, alumina 17 '40, chromium oxide 0*51, iron protoxide 7*79,
magnesia 3'41, lime 8'74, soda 3'72, potash 0'24, ignition 1 '93=99-86,
and the specific gravity 2*923. The variety obtained at Orezza is the
Verde di Corsica, of decorative art.
Occurs near Lake Geneva, in Savoy ; at Mt. Genevre in Dauphiny,
near the boundary between France and Italy ; at Allevard, in the
northeastern part of Isere ; in the valley of the Saas, north of east of
the Monte Rosa region ; in the Grisons ; near Leghorn and Bologna ;
near Florence, at Mt. Impruneta, it being the Oranitone (page 450)
of the Serpentine region ; on Corsica, in the Orezza valley; in Silesia ;
in I. of Unst. It is often associated with serpentine ; and the serpen-
tine and euphotide form beds in irregular masses among, and as a
constituent part of, a series of metamorphic strata, which include
green chloritic and talcose schists, limestone (which, at Mt. Genevre,
is of the Jurassic formation), and other rocks. For the Mt. Genevre
euphotide, Delesse obtained Silica 45'00, alumina and iron oxide
26-83, lime 8 '49, magnesia, soda and potash (by loss) 13 "90, water
and carbonic acid 6 '78, and for the saussurite the result stated on
page 410. The composition is near that of a labradioryte, and the dif-
ference in the two rocks must have depended on the different condi-
tions attending crystallization. The mixture of hornblende and py-
roxene in either foliated constituent, in connection with their mutual
positions and structure, proves that part of the hornblende is altered
pyroxene. The remark made on page 410 with reference to the pro-
duction of the saussurite may apply also to the foliated hornblende,
and therefore to the whole rock.
450 DESCRIPTIONS OF ROCKS.
6. PYROXENE AND SODA-LIME-FELDSPAR SERIES.
1, Augite-Andesyte. — Contains the same triclinic feldspar
as andesyte, but augite is present in place of hornblende.
Amount of silica obtained in analyses about 55 to 58 per
cent. Texture crystalline-granular to aphaiiitic ; colors dark
gray to greenish-black and brownish-black. G. = 2 '65 - 2 -90.
Eruptive.
VARIETIES. — There are two series : A. Ordinary, that is, without
chrysolite, or only in traces. B. Chrysolitic, chrysolite being in
disseminated grains or crystals. Under each there are varieties :
a. anhydrous ; b. hydrous, or chloritic, and feeble in lustre ; and
c. amygdaloidal, as well as chloritic. Again, each of these varieties
may be porphyritic. To the hydrous rock, and especially the chryso-
litic, the term Melaphyre is sometimes applied.
Quartz- Augite- Audesyte is described by Zirkel as occurring in Pali-
sade Canon, in Nevada Plateau ; it contains yellowish-brown augite,
some biotite, some grains of quartz. Silica 63 '71 per cent.
2. Gabbro or Hyperyte. (Gabbro, in part.). — A basic grani-
toid rock in part, consisting of cleavable labradorite with dis-
seminated pyroxene, or a granular crystalline aggregate of
the two minerals. The pyroxene is o'ften foliated, and has
been improperly called hypersthene. In place of labrador-
ite, the feldspar is sometimes andesite, and sometimes anor-
thite. Color, dull flesh-red to brownish-red, also dark-gray,
to grayish-black. Tough. G.= 2 '7-3-1, varying with the
proportion of pyroxene, which is sometimes small. Con-
tains also magnetite or titanic iron.
The name Gabbro has been applied to this rock ; also to a coarsely
granular igneous rock, consisting chiefly of labradorite and foliated
pyroxene, referred beyond to doleryte ; to euphotide ; and, by the
Italians, formerly to serpentine. Ferber, in his " Brief e " (1773), says
(p. 98): Gabbro of Florence is the same as the rock called "sachsi-
schen Serpentin, in Deutschland," that is, the serpentine of Zoblitz.
Again, on page 330, he says that Mt. Impruneta, seven Italian miles
from Florence, consists of Gabbro, or the so-called Saxon serpentine,
and he alludes to the occurrence in it of diallage and amianthus, and
the presence also " der sogenannte Granitone " "in horizontalen
Sehichten in den Gabbro-Bergen," which sometimes consisted " aus
weissem Feldspat, welcher grosse Parallelepipeden formirte," though
usually containing diallage.
VARIETIES. — a. Granitoid ; the feldspar in distinct cleavable grains
or masses, b. Fe2dspathose ; the pyroxene feeble in amount, c. Chry-
solitic; contains disseminated chrysolite, d. Anorthitic, or Tractolite ;
anorthite replaces the labradorite.
Includes the so-called hypersthenyte of the Adirondacks, Canada, and
Norway. Occurs also in the Laramie Hills, Colorado, a kind which
afforded, on analysis, Silica 52-14, alumina 29'17, iron oxide 3 '26, mag-
nesia 0-76, lime 10 81, soda 3-02, potash 0'98, ignition 0'58 = 100 '92.
KINDS OF ROCKS. 451
3. Noryte. Hypersthenyte. — A rock consisting of labrador-
ite or oligoclase, with true foliated hypersthene ; from St.
Paul's, Labrador, Hitteroe, Egersund, Harzburg; fine
grained, in Cortlandt, N. Y., between Cruger's and Peeks-
kill.
4. Doleryte. (Basalt, Trap.}— Chief constituents, labra-
dorite and augite, with magnetite, and sometimes anortbite.
Often porphyritic, and the feldspar crystals may be anor-
thite. Amount of silica yielded on analysis usually 47
to 52 per cent. Texture crystalline-granular to aphanitic;
and often, especially in the latter, having glassy particles
among the crystalline, or even an unindividualized base
or magma between the crystalline grains — the variety called
Basalt ; often coarse granular through the body of a dike,
while aphanitic along its walls, and sometimes containing
glassy portions in the latter when not elsewhere. Colors
dark grayish to bluish-black, greenish-black, and brownish-
black. 6. =2-75-3-1. Eruptive ; also metamorphic.
It includes the larger part of tlie rock usually called trap, abundant
inmost regions of igneous eruptions ; constitutes the "trap" ridges
of the Connecticut Valley, the Palisades of New Jersey, and similar
ridges in Nova Scotia and North Carolina ; also in the Lake Superior
region, and extensive beds of so-called basaltic rocks over the Rocky
Mountain slopes west of the Front Range. The rock of New Haven,
Conn., from West Rock, afforded Silica 51'78, alumina 14*20, iron ses-
quioxide 3-59, iron protoxide 8*25, manganese protoxide 0'44, magne-
sia 7'63, lime 10'70, soda 2 '14, potash 0'39, loss by ignition 0'63, phos-
phorus pentoxide 014=9989; G.=3 03. A hydrous or chloritic variety
from Saltonstall's Ridge, near New Haven, afforded Silica 49 '28,
alumina 15-92, iron sesquioxide 1-91, iron protoxide 10'20, manganese
protoxide 0'37, magnesia 5 '99, lime 7'44, soda 3'40, potash 0'72, water
3-90, carbon dioxide 1-14=100'72 ; G.=2'86.
VABIETIES. — There are two series : A. Ordinary, B. Chrysolitic,
and for the latter the name Pendotyte has been used. Each occurs :
a. anhydrous ; b. hydrous, or chloritic, of feeble lustre ; c. amygda-
loidal, as well as chloritic ; d. vesicular, or scoriaceous, as in doleritic
or basaltic lavas. JSpilite is amygdaloid.
Again, each of these varieties may be porphyritic. Again, the augite
may be in distinct crystals.
A coarse-granular kind, having the pyroxene foliated, is sometimes
called gabbro.
This basic rock, doleryte, is often called, also, basalt, especially
when it has an unindividualized base ; a specimen of this kind, from
Nevada, is represented in fig. 7, page 418. The name, anamedte,
has been used for an aphanitic kind, but is unnecessary.
Diabase. — The term diabase is very often applied to doleryte older
than Tertiary. It was formerly supposed that the former differed from
the latter in bain"- chloritic, and afterwards in never containing glassy
particles or an unindividualized base ; but neither distinction holds.
452 DESCRIPTIONS OF ROCKS.
The "antique green porphyry," or Porfido verde antico, figured on
page 415, in fig. 2, is a porphyritic rock of the composition of doleryte,
the feldspar being labradorite, and the other chief constituent, augite,
With also some chlorite, or viridite, which last is the source of the
greenish color. It is from the South Morea, between Lebetsova and
Marathonisi. Delesse obtained, from the compact base, Silica 53*55,
alumina 19 '84, iron protoxide 7'35, manganese protoxide 0'85, lime
8*02, soda and potash 7'9o, water 2'67. In view of its firmness, and
its contrast in this respect with most chloritic doleryte, it may be
queried whether the rock is not a metamorphic doleryte (metadoleryte).
It closely resembles the porphyritic labradioryte from the vicinity of
New Haven, Conn, (which is chloritic and metamorphic), though differ-
ing from it in containing pyroxene instead of hornblende. A similar
porphyry is reported from Elbingerode in the Hartz, Belfahy in the
Vosges, and Barnetjern near Christiania in Norway.
5. Eucryte. — A doleryte-like rock consisting chiefly of an-
orthite and augite. Occurs compact, and as a lava. From
Elfdalen, Norway.
6. Amphigenyte. (Leucitopliyre.} — Contains augite, like
doleryte, but leucite (called sometimes amphigene) replaces
the feldspar. Dark gray, fine-grained, and more or less cel-
lular to scoriaceous. G-.— 2-7-2-9. The leucite is dissemi-
nated in grains or in 24-faced crystals. Constitutes the
lavas of Vesuvius and some other regions. Accessory min-
erals, nephelite, biotite, chrysolite, sodalite, sanadin, labra-
dorite and nosean.
Hauynophyre is an amphigenyte from Vulture, near Melfi, in which
hauynite replaces much of the leucite.
7. Nephelinyte. (Nepheline-doleryte. ) — Contains augite,
like doleryte, but nephelite replaces the feldspar, or the larger
part of it. Crystalline-granular ; ash-gray to dark gray.
The nephelite is partly in distinct crystals.
8. Tachylyte. Hyalomelan. — Blackish glass, or pitchstone,
•made in connection with augitic igneous rocks or lavas ;
the former affords on analysis 49 per cent, of silica, and the
latter 55.
This Doleryte-pitcJistone may be porphyritic, or contain small grains
of augite, or of chrysolite.
7. PYROXENE, GARNET, EPIDOTE, AND CHRYSOLITE ROCKS.
CONTAINING LITTLE OR NO FELDSPAR.
1. Pyroxenyte. — Coarse or fine granular pyroxene rock.
Sometimes chrysolitic, a variety which occurs with chryso-
litic hornblendyte at the localities mentioned on p. 446.
2. Garnetyte, or Garnet Rock, — A yellowish-white to green-
KINDS OF ROCKS. 453
isli- white, tough rock, consisting of an alumina-lime garnet.
G.=3-39-3-49. From St. Francis, Canada. The superior
yellow iiovaculite or whetstone, of Vieil Salm, Belgium, has
the constitution, according to A. Kenard, of a manganesian
garnet. Metamorphic.
3. Eclogyte. — Compact and tough. Consists of granular
garnet and hornblende, with grass-green smaragdite. G. =
3-2-3-5. A related rock consists of reddish or brownish-
yellow garnet, and black or greenish-black hornblende, with
often some magnetite. Metamorphic.
4. Epidosyte. — Pale green to pistachio-green. Consists of
epidote mixed with quartz. Metamorphic.
5. Eulysyte. — Fine-granular, consisting of chrysolite with
a diallage-like mineral and garnet. Forms a bed in gneiss
near Tunaberg, Sweden.
6. Chrysolyte, or Chrysolite-Reck. — Yellowish to pale olive-
green, granular ; consisting almost wholly of chrysolite.
G-. =r 3-3-1; H. — 5-5-6. Abundant in Macon County, N.
Carolina ; in part changed to serpentine. Metamorphic.
Dunyte is yellowish-green ; granular, and consists of chrysolite, with
some chromite. From Mount Dun, New Zealand. Eruptive.
7. Lherzolyte. — Greenish-gray ; crystalline granular. Con-
sists of chrysolite, enstatite, whitish pyroxene, with chrome-
spinel and sometimes garnet. From Lake Lherz, etc. Is
it metamorphic ?
8. Picryte.— Blackish-green to brownish-red ; crystalline-
granular. Consists of chrysolite, with augite sometimes in
crystals. Graduates into chrysolitic doleryte. _
9. Limburgyte. — A semi-glassy rock, consisting of chryso-
lite and augite, with some magnetite. It is occasionally
amygdaloidal. Affords on analysis 43 per cent, of silica.
8. HYDROUS MAGNESIAN AND ALUMINOUS ROCKS.
Contain one or more of the hydrous magnesian minerals,
chlorite, talc, serpentine, or the related hydrous aluminous
mineral, pyrophyllite. The fine-grained kinds are more or
less greasy to the touch ; and some of them resemble the
hydromica slates.
1. Chlorite Schist.— Schistose ; color dark green to grayish-
green and greenish-black ; but little, if any, greasy to the
touch. Consists of chlorite, with usually some quartz and
454 DESCRIPTIONS OF ROCKS.
feldspar intimately blended, and often contains crystals
(usually octahedrons) of magnetite, and sometimes chlorite
in distinct scales or concretions. Metamorphic.
VARIETIES. — a. Ordinary, b. HornUendic ; the hornblende ingrains
or needles, c. Magnetitic. d. Tourmalmic. e. Garnetiferous. f. Pyr-
oxenic. g. Staurolitic. h. Epidotic. Graduates into argillyte.
2. Chlorite-Argillyte. — An argillyte or phyllyte consist-
ing largely of chlorite. Metamorphic.
3. Talcose Schist. — A slate or schist consisting chiefly of
talc. Not common, except in local beds, most of the so-
called "talcose slate" being hydromica schist (p. 440).
4. Steatyte, Soapstpne (p. 55).— Consists of talc. Mas-
sive, more or less schistose ; granular to aphanitic. Color,
gray to grayish -green and white. Feels very soapy. Easily
cut with a knife. Metamorphic.
VARIETIES. — a. Coarse-granular, and massive or somewhat schis-
tose, b. Fine-granular; "French chalk." c. Aphanitic, or Rens-
selaerite; of grayish-white, greenish, brownish to black colors, from
St. Lawrence County, N. Y. , and Grenville, Canada.
5. Serpentine. — Aphanitic or hardly granular ; of dark-
green to greenish-black color, easily scratched with a knife,
and often a little greasy to the feel on a smooth surface.
Although generally dark green, it is sometimes pale grayish
and yellowish-green, and mottled. Metamorphic.
Varieties. — a. Noble; oil -green and translucent, b. Common; opaque,
and of various colors, c. Schistose, d. Diallagic ; contains green or
metalloidal diallage. e. Chromiferous; contains chromite, a chromium
ore belonging to serpentine regions, f . B<tstitic ; contains bastite or
enstatite. g. Garnetiferous ; contains garnet, as at Zoblitz. h. Chry-
solitic ; contains chrysolite, i. Brecciated ; consists of united frag-
ments. (See also page 308.) Serpentine has been made by the altera-
tion of chrysolite beds, and of chondrodite and other magnesian sili-
cates. A rock consisting of serpentine and saussurite is true Gabbro.
6. Ophiolyte (Verd- Antique Marble). — A mixture of ser-
pentine with limestone, dolomite, or magnesite, having a
mottled green color. Often contains disseminated magne-
tite or chromite. Metamorphic.
VARIETIES. — a. Calcareous; the associated carbonate being cal cite,
b. Dolomitic ; the associated carbonate, dolomite, c. Magnesitic ; the
associated carbonate, magnesite. Either of these kinds may contain
chromite or magnetite. Handsome verd-antique marble has been ob-
tained near New Haven and Milford, Conn. A beautiful variety, hav-
ing pure serpentine disseminated in grains or spots through a whitish
calcite, occurs at Port Henry, Essex County, N. Y., and is worked.
KINDS OF ROCKS. 455
7. Pyrophyllyte and Pyrophyllite Slate.— Lil;e the preced-
ing in appearance and soapy feel, but having the composi-
tion of pyrophyllite (p. 306). The color is white and gray
or greenish white. Occurs in North Carolina. One of the
varieties from the Deep River region is used for slate pen-
cils. Metamorphic.
9. IRON-ORE ROCKS.
1. Hematyte. (Specular Iron Ore). — Hematite (p. 176), in
metamorphic beds. Color iron gray, and lustre bright me-
tallic, but varying to red and jaspery. Has the hardness of
crystallized hematite and its red streak. Constitutes beds
of great thickness in Archaean regions and thinner beds in
formations of later geological age ; alternates with horn-
blendic, chloritic, micaceous, and gneissoid, and sometimes
calcareous rocks, and often contains siliceous or jaspery
layers.
VARIETIES. — a. Iron-gray ; the ordinary massive kind. b. Red;
resembling a hard red jasper, into which it sometimes passes, c. Con-
taining martite; the octahedral crystals of martite having originally
been magnetite, and showing that they are changed to hematite by
their red streak, d. Foliated ; sometimes called micaceous iron ore,
in allusion to the foliation, e. Epidotic.
In large beds in the Archaean of Canada, St. Lawrence Co., N. Y.,
at Marquette, Northern Michigan, Missouri. At Nictaux, in Nova
Scotia, in semi-metamorphic fossilif erous Devonian there is a bed six
feet thick.
2. Itabyryte. — A mica schist consisting largely of
tite in laminae of bright metallic lustre.
3. Magnetyte. (Magnetic Iron Ore). — Magnetite (p. 178),
in metamorphic beds. Color iron gray to grayish black,
and lustre metallic ; never bright red. Strongly attracted
by the magnet, and hence often separated from the gangue,
after crushing it, by means of large electro-magnets. Con-
stitutes, like hematite, thick beds in Archaean regions, and
thinner in rocks of other periods.
VARIETIES. — a. Massive, b. Granular, c. Epidotic. d. Horriblendic.
e. Chloritic. f. Titanic, g. Chondroditic ; as near Brewster, N. Y.,
where chondrodito is the " gangue" of the ore.
Metamorphic magnetite constitutes thick beds in the Archaean of
Canada, Northern New York, Orange Co., N. Y., Sussex Co., N. J.,
and occurs also in Virginia, east of the Blue Ridge, in
456 . DESCRIPTIONS OF ROCKS.
Essex, and Nelson counties, and elsewhere. Forms a small bed in the
Upper Silurian of Bernardston, Mass., and in Devonian, at Moose River,
in Nova Scotia.
4. Menaccanyte. (Titanic Iron Ore). — Resembles massive
hematite, but consists chiefly of titanic iron (p. 178). Oc-
curs in the Archaean of Canada, as in the parish of St. Ur-
bain, at Bay St. Paul, where the bed is ninety feet thick.
5. Franklinyte. — Resembles massive magnetite, but con-
sists of franklinite (p. 179), which differs from magnetite in
containing more or less zinc and manganese.
Occurs at Mine Hill, in Hamburg, N. J., and also at Stirling Hill, in
the same region, constituting a bed of great thickness. It is mixed
•with zinc ores, zincite and willemite, besides other minerals, and asso-
ciated with granular limestone, in an Archaean region of hornblendic
and gneissoid rocks.
For non-metamorphic kinds of iron ores, see under HEMATITE
(p. 176), LIMONITE (p. 181), and SIDERITE (p. 185). Beds of magne-
tite occur only in metamorphic region*.
GENERAL INDEX.
Acadialite, 300.
Acanthite, 118.
Acmite, 247.
Actinolite, 249.
Actinolyte, 446.
Adamantine spar, 193.
Adamite, 156.
Adularia, 278.
JSgirine, JSgyrite, 247.
^Eschynite, 202, 260.
Agalmatolite, 306, 312.
Agate, 236.
Aikinite, 136, 149.
Akanthit, v. Acanthite.
Alabandite, 188.
Alabaster, 210.
Albertite, 326.
Albite, 277.
Alexandrite, 196.
Algodonite, 135.
Alipite, 168.
Alisonite, near Covellite, 133.
Allanite, 203, 263.
Allemontite, 101.
Allopalladium, 127.
Allophane, 296.
Allophite, 318.
Alluaudite, 191.
Alluvium, 429.
Almandin, Almandite, 257.
Altaite, 149.
Alum, native, 198.
Alum shale, 428,
Alum stone, 198.
Aluminite, 199.
Aluminum, Compounds of, 192.
fluorides, 197.
Alunite, 198.
Alunogen, 197.
Amalgam, 117, 128.
Amazonstone, 278.
20
Amber, 325.
Amblygonite, 44, 199.
Ambrite, 325.
Amethyst, 235, 239.
Oriental, 193.
Amianthus, 250, 308.
Ammonium alum, 198, 231.
Ammonium, Salts of, 230.
Amphibole, 249.
Arnphibolyte, 446.
Amphigene, 271.
Amphigenyte, 452.
Amygdaloid, 418, 451.
Analcite, Analcime, 69, 299.
Anatase, 451.
Anamesite, 163.
Ancramite, 159.
Andalusite, 284.
Andesine, Andesite, 276.
Andesyte, 447.
Andradite, 258.
Andre wsite, 185.
Anglesite, 150.
Anhydrite, 211.
Ankerite, 186, 220.
Annabergite=Nickel arsenate.
Annite, 266.
Anorthite, 44, 275.
Anthophyllite, 252.
Anthracite, 327.
Anthraconite, 217.
Antigorite, 308.
Antillite, 309.
Antimonate, Calcium, 214.
Copper 139.
Lead, 152.
Antimonial copper ores, 135, 136.
lead ores, 149.
nickel ores, 166.
silver ores, 119, 120.
Antimonite,
457
458
GENERAL INDEX.
Antimony, Native, 100.
glance, ?>. Stibnite.
Apatite, 46, 48, 49, 67, 213.
Aphanesite, 139.
Aphrodite, 307.
Aphrosiderite, 319.
Aphthitalite, 227.
Apjohnife; 198.
Aplome, 258.
Apophyllite, 294.
Aquamarine, 252.
Aragonite, 218.
Aragotite, 324.
Arcanite, 227.
Arfvedsonite, 252.
Argentine, 121, 216".
Argentite, 117, 121.
Argillyle, 428.
Arkansite, 163.
Arkose, 436.
Arksutite, 197.
Arquerite, 117.
Arragonite, 218..
Arsenate, Calcium, 214.
Cobalt, 167, 168.
Copper, 139.
Iron, 185.
Lead, 152.
Uranium, 170, 171.
Zinc, 156.
Arsenic, Native, 98.
Arsenic group, 98.
sulphide, 99.
White, 99.
Arsenical antimony, 101.
cobalt, 165r 166,
iron ore, 175, 176.
lead ores, 149.
nickel, 165, 166.
Arsenide, Cobakr 165^ 166i
Copper, 135.
Iron, 175, 176.
Manganese, 188.
Nickel, 165, 166.
Arsenioaiderite, 185.
Arsenolite. 99.
Arsenopyrite, 175.
Asbestua, 246, 250.
Blue, -0. Crocidolite.
Asbolan, Asbolite, 167.
Asmanite, 241.
Asparagus-stone, 213.
Aspasiolite, 315.
Asphaltum, 326.
Aspidolite, 266.
Astrakanite, v. Blodite.
Astrophyllite, 266.
Atacamite, 136.
Atopite, 214.
Auerbachite, 260.
Augite, 245.
andesyte, 450.
Augitic trachyte, 448.
Aurichalcite, 141, 157.
Auriferous pyrite, 173.
Auripigmentum, 99.
Automolite, 196.
Autunite, 170.
Aventurine quartz, 235.
feldspar, 279.
Axinite, 44, 264.
Azurite, 141.
Babingtonite, 247.
Bagrationite, ID. Allanite.
Baltirnorite, 308.
Banatite, 447.
Barite, 220.
Barium, Compounds of, 220.
Barytes, 220.
Barytocalcite, 222.
Basalt, 451.
Basanite, 237.
Bastite, 309.
Bathvillite, 325.
Beaumontite, 304.
Bechilite, 212.
Benzole, 324.
Berthierite, 176.
Beryl, 46, 252.
Berzelianite, 135.
Beyrichite, 165.
Bieberite, 168.
Biharite, 312.
Bindheimite, 152.
Binnite, 136.
Biotite, 266.
Bismite, 102.
Bismuth, 101.
Bismuth glance, «. Bismuthinitc.
Bismuth ores, 102.
carbonate, 102.
Bismuth nickel, 166.
Bismuth silver, 116.
Bismuthinite, 102.
Bismutite= Bismuth carbonate.
GENERAL INDEX.
459
Bismutoferrite, 256.
Bitter spar, v. Dolomite.
Bitumen, 326.
Elastic, 324.
Bituminous coal, 327.
Bituminous shale, 428.
Black cobalt, 167.
copper, 137.
jack, 155.
lead, 107.
silver, 119.
Blende, 154.
Blodite, 206, 227.
Blomstraudite, 170.
Bloodstone, 237.
Blue iron earth, 185.
copper, 133.
vitriol, 137.
Bodenite, 263.
Bog iron ore, 181.
manganese, 190.
Bole, Halloysite, 312.
Boltonite, 256.
Boracic acid, 97.
Boracite, 206.
Borate, Ammonium, 231.
Calcium, 212.
Hydrogen, 98.
Iron, 182.
Magnesium, 206.
Sodium, 212, 227.
Borax, 227.
Bornite, 134
Borocalcite, 212.
Boronatrocalcite, 212.
Boron group, 97.
Bort, 103.
Bosjemanite, 198.
Botryogen, 182.
Botryolite, 289.
Boulangerite, 149.
Bournonite, 136.
Boussingaultite, 231.
Bowenite, 309.
Bragite, 260.
Branchite, 324.
Brandisite, 320.
Brass, composition of, 144.
Braunite, 189.
Bravaisite, 302.
Breccia, 426.
Bredbergite, 258.
Breislakite, v. Pyroxene.
Breithauptite, 166.
Breunerite = Ferriferous Magne-
site.
Brewsterite, 304.
Brittle silver ore, 119.
Brochantite, 138.
Bromargyrite, 121.
Bromic silver, 121.
Bromlite, 222.
Bromyrite, 121.
Brongniardite, 120, 149.
Bronze, 144.
Bronzite, 244.
Brookite, 163.
Brown coal, 327.
hematite, 181.
iron ore, 181.
ochre, 181.
spar, 219.
stone, 427.
Brucite, 204.
Brushite, 214.
Bucholzite, 285.
Bucklandite, 262.
Buhrstone, 437.
Buratite, 141, 157.
Cacholong, 240.
Cacoxenite, Cacoxene, 185.
Cadmium, Ores of, 159.
Cairngorm stone, 235.
Caking coal, 327.
Calaite, v. Callaite.
Calamine, 157, S96.
Calaverite, 115.
Calcite, 49, 50, 215.
Calcium, Compounds of, 207.
Calc spar, 215.
Caledonite, 149.
Callainite, 200.
Callais, Callaite, 200.
Calomel, 129.
Canaanite= White Pyroxene, 245.
Cancrinite, 270.
Cannel coal, 327.
Cantonite, near Covellite, 133.
Caoutchouc, Mineral, 324.
Capillary pyrites, 164.
Carbonaceous shale, 428.
Carbonado, 103.
Carbonate, Ammonium, 231.
Barium, 221.
Calcium, 215, 218, 219.
460
GENERAL INDEX.
Carbonate, Bismuth, 102.
Cerium, 203.
Copper, 140, 141.
Iron, 185.
Lanthanum, 203.
Lead, 152.
Magnesium, 207, 219,
Manganese, 191.
Sodium, 229, 230.
Strontium, 223.
Uranium, 171.
Yttrium, 203.
Zinc, 156.
Carbonic acid, 108, 423.
Carburetted hydrogen, 321.
Carnallite, 205.
Carnelian, 236.
Carpholite, 296.
Carrara marble, 433.
Cassiterite, 160.
Castor, Castorite, 249.
Catapleiite, 295.
Cataspilite, 312.
Catlinite, 429.
Cat's-eye, 236.
Celadonite, 307.
Celestite, Celestine, 222.
Cerargyrite, 120, 121.
Cerite, 298.
Cerium ores, 201.
Cerolite, 309.
Cerussite, 152.
Cervantite, 101.
Chabazite, 800.
Chalcanthite, 137.
Chalcedony, 235.
Chalcocito, 133.
Chalcodito, 307.
Chalcolite, 170.
Chalcomorphite, 296.
Chalcophanite, 189.
Chalcophyllite, 139.
Chalcopyrite, 133.
Chalcosiderite, 185.
Chalcosine, 133.
Chalcostibite, 136.
Chalcotrichite= Capillary Cuprite,
136.
Chalk, 215, 432.
Chalybite — Siderite.
Chathamite, <y. Chloanthite.
Chert, 287, 436.
Chessy Copper, v. Azurite.
Chesterlite, v. Microcline.
Chiastolite, 285.
Childrenite, 200.
Chiolite, 197.
Chloanthite, 165.
Chlor -apatite, 213.
Chlorastrolite, 296.
Chloride, Ammonium, 230.
Copper, 136.
Lead, 149, 153.
Magnesium, 205.
Mercury, 129.
Potassium, 224.
Silver, 120.
Sodium, 224.
Chlorite argillyte, 454
Group, 316.
schist, 453.
Chloritoid, 320.
Chlormagnesite, 205.
Chloropal, 307.
Chlorophaeite, 318.
Chlorophane, 208.
Chlorophyllite, 265, 315.
Chlorotile, 139.
Chodneffite, 197.
Chondrodite, 281.
Chonicrite, 317.
Chromate, Lead, 150, 151.
Chrome yellow, 151.
Chromic iron, 180.
Chromite, 180.
Chrysoberyl, 196.
Chrysocolla, 142, 295.
Chrysolite, 255.
rock, 453.
Chrysolyte, 453.
Chrysoprase, 236.
Chrysotile, 308.
Churchite, 203.
Cimolite, 307.
Cinnabar, 128.
Cinnamon stone, 257.
Cipolin marble, 434.
Citrine, 235.
Claudetite, 100.
Clausthalite, 149.
Clay, 429.
iron-stone, 177, 181, 186
slate, 428.
Cleavelandite, 278.
Cleiophane, 155.
Cleveite, 170.
GENERAL INDEX.
461
Clingmanite, 319.
Clinkstone, 444.
Clinochlore, 319.
Clinoclasite, 139.
Clinohumite, 281.
Clintonite, v. Seybertite.
Coal, Mineral, 327.
Brown, 328.
Cannel, 327.
Cobalt bloom, 167.
glance, 165.
Ores of, 163.
pyrites, 164.
vitriol, 168.
Cobaltite, Cobaltine, 165.
Coccolite, 246.
Coke, 328.
Collyrite, 296.
Colophonite, 258.
Coloradoite, 129.
Colorados, 121.
Columbates, 170, 183, 202,
214.
Columbite, 183.
Columbium, 184.
Comptonite, 298.
Conglomerate, 426.
Connellite, 47 (f. 11), 138.
Cookeite, 314.
Copal, Fossil.
Copaline, Copalite, 325.
Copiapite, 182.
Copper, Native, 131.
froth, 139.
glance, 132.
Gray, 135.
mica, 130.
nickel, 166.
Ores of, 130.
pyrites, 133, 134
vitriol, 137.
Copperas, 182.
Coprolites, 213.
Coquimbite, 182.
Cordierite, 264.
Corneous lead, 153.
Cornwallite, 139.
Corsyte, 448.
Corundellite, 319.
Corundophilite, 319.
Corundum, 192.
Cossaite, 314.
Cotunnite, 149.
203,
Covellite, Covelline, 133.
Crednerite=Cu ,Mn2O6.
Crichtonite, ». Menaccanite.
Crocidolite, 252.
Crocoite, Crocoisite, 150.
Cronstedtite, 319.
Crookesite, 135.
Cryolite, 197.
Cryophyllite, 268.
Cryptolite, 203.
Cryptomorphite, 212.
Cubanite, 134.
Cube ore, 185.
Cubic nitre, 229.
Culsageeite, 317.
Cummingtonite, 250.
Cuprite, 136.
Cuproscheelite, 212.
Cuprotungstite, 138.
Cyanite, 286.
Cyanotrichite, 138.
Cymatolite, 248.
Cyprine, 261.
Daleminzite, 118.
Damourite, 313, 441.
Danaite, 175.
Danalite, 256.
Danburite, 264.
Datholite, Datolite, 289.
Daubreelite, 180.
Daubreite,— Bismuth oxichloride,
Dawsonite, 201.
Dechenite=Lead vanadate.
Degeroite, 315.
Delessite, 318.
Delvauxite, v. Dufreni'je.
Dendrites, 59.
Derbyshire spar, 209.
Descloizite,
Desmine, 303.
Deweylite, 309.
Diabantachronyn, 318.
Diabantite, 318.
Diabase, 452.
Diallage, Green, 246.
Diallogite, t>. Rhodochrosite.
Diamond, 103.
Dianite, u. Columbite.
Diaphorite = Trimetric Frelesleb.
enite.
Diaspore, 194.
Dichroite, 264
4G2
GENERAL INDEX.
Bickinsonite, 191.
Didymium ores, 201, 203.
Bihydrite, 139.
Binite, 324.
Biopside, 246.
Dioptase, 141, 256, 295.
Bioryte, 446.
Biphanite, 319.
Bipyre, 209.
Bisterrite, 320.
Bisthene, 286.
Bitroyte, 444.
Bog-tooth Spar, 215.
Bolerophanite, 138.
Boleryte, 451.
pitchstone, 452.
Bolomite, 207, 219.
Bolomyte, 43'3, 434.
Bomeykite, 135.
Bomyte, 443.
Breelite, 221.
Bry-bone, 158, 364.
Budleyite, 320.
Bufrenite, 185.
Bufrenoysite, 149.
Bunyte, 453.
Burangite, 199.
Butch white, 221.
Bysanalyte, 202, 214.
Byscrasite, 119.
Bysluite, 196.
Bysodile, 325.
Bysyntribite, 312.
Earthy cobalt, 167.
Ecdemite, 152.
Eclogyte, 453.
Edelforsite, 245.
Edenite, 251.
Edingtonite, 296.
Edwardsite, •». Monazite.
Ehlite, 139.
Ekebergite, 269.
Ekmannite, 316.
Elseolite, 269.
Elaterite, 324.
Electro-silicon 430.
Electrum, 110
Eliasite, 170.
Embolite, 121.
Embrithite, v. Boulangerite.
Emerald, 252.
Oriental, 193.
Emerald, nickel, 168.
Emery, 193.
Emerylite, 319.
Emplectite, 136.
Enargite, 136.
Enceladite, «. Warwickite.
Eustatite, 244.
Enysite, 138.
Eosite, near Vanadinite.
Eosphorite, 200.
Epichlorite, 316.
Epidosyte, 453.
Epidote, 262.
Epistilbite, 302, 304.
Epsom salt, Epsomite, 205.
Erbium ores, 201.
Erdmannite, 296.
Erinite, 139.
Erubescite, 134.
Erythrite, 167.
Esmarkite, 265, 315.
Eucairite, 118, 135.
Euchroite, 139.
Euclase, 288.
Eucolite, 254.
Eucrasite, 296.
Eucryte, 452.
Eudyalite, Eudialyte, 254, 260.
Eudnophite, 300.
Eukairite, V. Eucairite.
Eulysyte, 453.
Eulytite, Eulytine, 102, 256.
Euosmite, 325.
Euphotide, 449.
Euphyllite, 314.
Eupyrchroite, 213.
Euralite, 318.
Euryte, 442.
Euxenite, 202.
Fahlerz, 135.
Fahlunite, 265, 314.
Fairfieldite, 191.
Fassaite, 246.
Faujasite, 300.
Fayalite, 256.
Feather ore, v. Jamesonite.
Feldspar Group, 272.
Felsite, 280.
Felspar, v. Feldspar.
Felsyte, 442.
Fergusonite, 202, 260.
Fibrofemte, 182.
GENERAL INDEX.
463
Fibrolite, 285.
Fichtelite, 324.
Fiorite, 240.
Fioryte, 437.
Fireblende v. Pyrostilpnite.
Fire-marble, 431.
Fire-opal, 239.
Fischerite, 200,
Flint, 237.
Float-stone, 241.
Flos ferri, 218.
Flueliite, 197.
Fluidal texture, 418.
Fluocerine, 202.
Fluocerite, 202.
Fluor-apatite, 213.
Fluor, Fluorite, 208.
Fluor spar, 208.
Fluorides, Aluminum, 197.
Calcium, 208.
Foliated tellurium, 149.
Fontainebleau limestone, 216.
Foresite, 304.
Forsterite, 255.
Fowlerite, 247.
Foyayte, 446.
Franklinite, 158, 179, 456.
Free-stone, 427.
Freibergite — Argentiferous Tetra-
hedrite.
Freieslebenite, 120, 121, 149.
Frenzelite, 102.
Friedelite, 256.
Gabbro, 449, 450, 454
Gadolin, Gadolinite, 203, 263.
Gagates, 328.
Gahnite, 196.
Galena, Galenite, 121, 145.
Galmei, 157.
Ganomalite, 153.
Garnet, 256.
rock, 452. ;
Garnetyte, 452.
Garnierite, 168.
Gastaldite, 252.
Gay-Lussite, 230.
Gearksutite, 197.
Gehlenite, 284.
Genthite, 168, 309.
Geocerite, 325.
Geocronite, 149.
Geomyricite, 325.
Gersdorffite, 166.
Geyserite, 240, 437.
Gibbsite, 194.
Gieseckite, 270, 313.
Gigantolite, 265 315.
Gillingite, 316.
Girasol, 239.
Gismondite, Gismondine, 296.
Glagerite, 312.
Glaserite, v. Arcanite,
Glass, 416.
Glauber salt, 41, 68, 226.
Glanberite, 227.
Glaucodot=Cobaltic Arsenopyrite.
Glaucolite, 269.
Glauconite, 307, 429.
Glaucophane, 252, 446.
Globulites, 416.
Gmelinite, 301.
Gneiss, 439.
Gold, 109.
Goslarite, 156.
Gothite, 182.
Grahamite, 326.
Gramenite, 307.
Grammatite, 249.
Granite, 437,
Granitone, 449, 450.
Granular quartz, 435.
Granulyte, 439.
Graphic granite, 438, 439.
tellurium, 118.
Graphite, 107.
Grastite, 319.
Gray antimony, «. Stibnite,
copper, 135.
Green earth, 307.
sand, 429.
Greenockite, 159.
Greenovite, 290.
Greenstone, 446, 448.
Greisen, 441.
Grindstones, 427.
Grit, 426.
Grochauite, 319.
Groppite, 314.
Grossularite, 257.
Grunauite, 166.
Guadalcazarite, 129.
Guanajuatite, 102.
Guano, 213.
Guarinite, 291.
Gummite, 170.
4-G4
GENERAL INDEX.
Gurhofite, 219.
Guyaquillite, 325.
Gymnite, 309.
Gypsum, 56, 210.
Gyrolite, 293.
Haidingerite, 214
Hair-salt, 205.
Halite, 224.
Hallite, 318.
Halloysite, 312.
HalotricMte, 182, 198.
Hamburg1 white, 221.
Harmotome, 301.
Harrisite, 133.
Haitite, 324.
Hatchettite, Hatchettine, 324.
Hatchettolite, 170, 214.
Hauerite, 188.
Haureaulite, 191.
Hausmannite, 189.
Hauyne, Haiiynite, 270.
Hauynophyre, 452.
Haydenite, 301.
Hayesine, 212.
Heavy spar, 220.
Hebronite, 199.
Hedenbergite, 246.
Hedyphane, 152.
Heliotrope, 237.
Helminthe, 319.
Helvite, Kelvin, 256.
Hematite, 176, 455.
Brown, 181, Red, 176.
Hemi-dioryte, 443.
Henwoodite, 200.
Hercynite, 196. .
Herderite, 199.
Herschelite, 301.
Hessite, 118.
Hetaerolite, 189.
Heterosite, 191.
Heulandite, 303.
Hisingerite, 315.
Hcernesite, 207.
Homilite, 289.
Honey-stone, 201.
Hopeite, 158.
Hornblende, 249, 251.
schist, 446.
Horn quicksilver, 129.
silver, 120.
Hornstone, 237.
Horse-flesh ore, v. Bornite.
Hortonolite, 256.
Houghite, 194.
Howlite, 212.
Huascolite, 155.
Hiibnerite, 183.
Hudsonite, 246.
Humboldtilite, 261.
Humboldtite, 289.
Humite, 281.
Hureaulite, 191.
Hyacinth, 259, 260, 284.
Hyalite, 240.
Hyalomelan, 452.
Hyalophane, 276.
Hyalosiderite, 255.
Hyalotecite, 153.
HydrargiJlite, 194.
Hydraulic limestone, 217, 431
Hydroboracite, 212.
Hydrocarbons, 320.
Hydrocerussite, 153.
Hydrochloric acid, 231.
Hydrocyanite, 138.
Hydrodolomite, 220.
Hydrogen, 231.
Hydromagnesite, 204, 207.
Hydro-mica Group, 312.
Hydromica schist, 440.
Hydrophane, 240.
Hydrophite, 309.
Hydrotalcite, 194.
Hydrozincite, 157.
Hypersthene, 244.
Hypfrsthenyte, 450, 451.
Hyperyte, 450.
Iberite, 315.
Ice, crystallization of, 4.
Iceland spar, 215.
Idocrase, 261.
Idrialine, Idrialite, 324.
Ihleite, 182.
Ilmenite, 178.
Ilvaite, 263.
Inclusions, 423.
Indianite, 275.
Indicolite, 283.
Infusorial earth, 241.
lodargyrite, 121.
Iodide, Mercury, 129.
Silver, 121.
lodyrite, 121.
GENERAL INDEX.
465
lolite, 264.
Hydrous, Slo".
lonite, 325.
Iridosmine, 127.
Iron, 171.
Iron, Ores of, 171, 455.
Magnetic, 178, 455.
pyrites, 172.
sinter, 185.
Ironstone, Clay, 177, 181.
Isenite, 448.
Iserine, u. Menaccanite.
Isoclasite, 139.
Itabyrite, 440, 455
Itacolumyte, 104, 436.
Ittnerite, 270.
Ixolyte, 324.
Jade, 250.
Jadeite, 263.
Jamesonite, 149.
Jargon, 260.
Jarosite, 182.
Jasper, 237.
rock, 437
Jaspery clay iron-stone, 177.
Jefferisite, 317.
Jeffersonite, 246.
Jelletite, 258.
Jenkinsite, 309.
Jenzscliite, 241.
Jet, 328.
Johannite, 171.
Jollyte, 316.
Joseite, 102.
Kalinite, 198.
Kammererite, 318.
Kaneite, 188.
Kaolin, Kaolinite, 280, 310.
Karyinite, 152.
Keiihauite, 203, 291,
Kermesite, 101.
Kerrite, 318.
Kersanton, Kersantyte, 444
Kerstenite, 150.
Kieserite, 205.
Killinite, 248.
Kinzigyte, 444.
Kjerulftne, 207.
Knebelite, 256.
Kobellite, 149.
Kochelite, 202.
Kongsbergite, 117.
Konigite, Konigine, 138.
Konlite, 324.
Kottigite, 156, 167.
Kotschubeite, 319.
Kreittonite, 196.
Krennerite, 116.
Krisuvigite, 138.
Kronkite, 138.
Kupfferite, 252.
Kyanite, 286.
Labradioryte, 448.
Labrador feldspar, 27(5.
Labradorite, 276.
Labradorite-dioryte, 448.
Lagonite, 182.
Lampadite, 190.
Lanarkite, 151.
Langite, 138.
Lanthanite, 203.
Lanthanum ores, 201.
Lapis-lazuli, 270.
Lapis ollaris, 304.
Larderellite, 231.
Latrobite, v. Anorthite.
Laumontite, Laumonite, 293.
Laurite, 127.
Lazulite, 199.
Lead, ores of, 145
Leadhillite, 151.
Lecontite, 231.
Lederite, 291.
Lehrbachite, 149.
Lenzinite, 312.
Leopoldite, v. Sylvite.
Lepidokrokite, 182.
Lepidolite, 268.
Lepidomelane, 266.
Leptinyte, 439.
Lettsomite, v. Cyanotrichite.
Leuchtenbergite, 319.
Leucite, 271
Leucitophyre, 452.
Leucityte, 443.
Leucophanite, 256.
Leucopyrite, 176.
Levyne, Levynite, 301.
Lherzolyte, 453.
Libethenite, 139.
Liebigite, 171.
Lievrite, <D. Ilvaite.
Lignite, 328.
466
GENERAL INDEX.
Lillite, 316.
Limbacliite, 309.
Limburgyte, 453.
Lime-titanate, v. Perofskite.
Limestone, 216, 430, 432.
Limnite, 182.
Limonite, 181.
Linarite, 138.
Lindackerite, 168.
Linnaeite, 164.
Liroconite, 139.
Lithiophilite, 190.
Litliium phosphates, 190, 199.
Lithographic stone, 217.
Lithomarge, 312.
Liver ore, 129.
Livingstonite, 101.
Lodestone, 141, 179.
Loess, 4-29.
Loganite, 318.
Lollingite, 176.
Lophoite, 319.
Loweite, 227, 206.
Lowigite, 199.
Loxoclase, 278.
Ludlamite, 185.
Ludwigite, 206.
Lumachelle, 431.
Liineburgite, 207.
Lydian stone, 237.
Lyncurium, 284.
Made, 285.
Maconite, 318.
Magnesite, 207.
Magnesium, Compounds of, 204.
Magnetic iron ore, 178, 455.
pyrites, 174.
Magnetite, 59, 178, 423.
Magnoferrite, 204.
Magnolite, 129.
Malachite, Blue, 141.
Green, 140, 200.
Malacolite, 246.
Malacon, 260.
Maldonite, 110.
Malinowskite, 136.
Manganblende, 188.
Manganepidot, «. Epidote.
Manganese ores, 188.
spar, 247.
Manganite, 189.
Marble, 216, 431, 432.
Marble, Verd-antique, 454
Marcasite, 174.
Margarite, 319.
Margarodite, 313.
Margarophyllite Section, 304.
Marialite, 269.
Marl, 432.
Marmatite, v. Sphalerite.
Marmolite, 308.
Marsh gas, 321.
Martite, 177.
Mascagnite, Mascagnine, 231.
Masonite, 320.
Matlockite=Lead oxichloride.
Medjidite, 171.
Meerschaum, 306.
Meionite, 269.
Melaconite, 137.
Melanite, 258.
Melanochroite, 151.
Melanolite, 315.
Melanophlogite, 241.
Melanterite, 182.
Melaphyre, 450.
Melilite, Mellilite, 261.
Melinophane, 256.
Meliphanite, 256.
Mellite, 201.
Menaccanite, 178.
Mendipite, 149.
Mendozite, 198.
Meneghinite, 149.
Menilite, 240.
Mercury, Ores of, 128.
Native, 128.
Mesitine, Mesitite, 186.
Mesolite, 299.
Mesotype v. Natrolite.
Metabrushite, 214.
Metachlorite, 319.
Metacinnabarite, 129.
Metadoleryte, 452.
Metaxite, 308.
Metaxoite, 317.
Miargyrite, 120.
Miarolyte, 438.
Miascyte, 444.
Mica, 265.
Mica-argillyte, 441.
dioryte, 444.
phyllyte, 441.
schist, 440.
Michaelsonite, 263.
GENEKAL INDEX,
467
Microcline, 278.
Microlite, 202, 214.
Microlites, 416, fig. 6.
Microsommite, 270.
Middletonite, 325.
Milarite, 252.
Millerite, 164.
Millstone grit, 426.
Mimetene, Mimetite, 46, 152.
Mineral coal, 327.
oil, 321.
pitch, 326.
Minette, 441.
Minium, 149.
Mirabilite, 41, 226.
Misenite, 227.
Mispickel, 175.
Mizzonite, 269.
Mocha stone, 236.
Molybdate, Lead, 151.
Molybdenite, 96.
Molybdite, 97.
Monazite, 41, 203.
Monimolite, 152.
Monradite, 295.
Montanite, 102.
Monticellite, 256.
Montmartite, v. Gypsum.
Montmorillonite, 307.
Montronite, 307.
Moonstone, 277, 279.
Mordenite, 304.
Morenosite, 168.
Mosandrite, 263.
Moss agate, 236.
Mottramite, 139.
Mountain cork, 250.
leather, 250.
tallow, 324.
Muller's glass, 240.
Mundic, 174.
Muntz metal, 144.
Muriatic acid, 231.
Muromontite, 263.
Muscovite, 267.
Muscovy glass, 268.
Miisenite, v. Siegenite.
Nadorite, 152.
Nagyagite, 116, 149.
Naphtha, 321.
Naphthaline, 324.
Natroborocalcite, 212.
Natrolite, 299.
Natron, 229,
Naumannite, 118.
Needle ore, v, Aikinite.
Neft-gil, 324.
Nemalite, 204
Neotocite, 316,
Nepheline-doleryte, 452.
Nephelinyte, 452,
Nephelite, Nepheline, 269.
Nephrite, 250.
Newjanskite, 127,
Niccolite, 166.
Nickel glance, n. Gersdorffite.
Nickel-gyomite, 309.
Nickel, Ores of, 164.
stibine, 166,
Nigrine, 162.
Niobite, V, Columbite.
Niobium, Compounds of, 184.
Nitrate, Calcium, 214.
Potassium, 22a
Sodium, 229.
Nitratine, 229.
Nitre, 228.
Nitrocalcite, 214.
Nitromagnesite, 206.
Nohlite, 202.
Noryte, 450.
Nosean, Nosite, 270.
Noumeite, 168.
Novaculyte, 436, 453.
Nuttalite, 269.
Ochre, Red, 167, 176,
Yellow, 181.
Octahedrite, 163.
CEllacherite, 314.
CErstedite, 260,
Ogcoite, 319.
Okenite, 293.
Oligoclase, 44, 276.
Olivenite, 139.
Olivine, 255.
Onyx, 236.
Oolite, 216.
Opal, 239.
Opal, Jasper, 240.
Ophiolite, 308.
Ophiolyte, 454.
Ophite, 447.
Orangite, 296.
Orpiment, 99.
468
GENERAL INDEX.
Orthite, 263.
Orthoclase, 44, 278.
Osteolite, 213.
Ottrelite, 320.
Ouvarovite, 258.
Oxide, Cobalt, 167.
Iron, 176.
Lead, 149.
Magnesium, 204.
Manganese, 188.
Tin, 160.
Uranium, 169.
Zinc, 155.
Ozarkite, 298.
Ozocerite, Ozokerite, 324
Pachnolite, 197.
Pacos, 121.
Pagodite, 312.
Palagonite, 312.
Palladium, 127.
Paraffin, 324.
Paragonite, 314.
schist, 441.
Paranthine, 269.
Parasite, v. Boracite.
Pargasite, 251.
Parisite, 203.
Parophite, 314.
Parophite schist, 441.
Pattersonite, 319.
Pealite, v. Geyserite.
Pearl sinter, 437.
spar, 219.
stone, 443.
Pectolite, 293.
Peganite, 200.
Pegmatolite, v. Orthoclase.
Pegmatyte, 438, 439.
Pelagite, 189.
Pelhamite, 318.
Pencil-stone, 306.
Pennine, Penninite, 318.
Pennite, 220.
Peperino, 429.
Periclase, Periclasite, 204.
Peridot, v. Chrysolite.
Peridotyte, 451.
Perofskite, Perowskit, 163.
Petalite, 248.
Petroleum, 321.
Petrosilex, 442.
Petzite, 116, 118.
Phacolite, 301.
Pharmacolite, 214.
Pharmacosiderite, 185',
Phenacite, 254.
Phillipite, 138.
Phillipsite, 302.
Phlogopite, 68, 266.
Phcenicochroite, 151.
Pholerite, 312.
Phonolyte, 444.
Phosgenite, 153.
Phosphate, Aluminum, 199, 200.
Ammonium, 231.
Calcium, 212, 214.
Cerium, 203.
Copper, 139.
Iron, 184, 185, 191.
Lead, 151.
Manganese, 190, 191.
Uranium, 170.
Yttrium, 203.
Phosphochalcite, 139.
Phosphorite,213.
Phrenite, 295.
Phyllite, 320.
Phyllyte, 428.
Physalite, 287.
Pickeringite, 198.
Picotite, 195.
Picrolite, 308.
Picromerite, 205, 227.
Picrophyll, 295.
Picrosmine, 295.
Picryte, 453.
Piedmontite, 262.
Pilinite, 304.
Pimelite, 168.
Pinguite, 307.
Finite, 312.
Pinitoid, 312.
Pipe- clay, 427.
Pipestone, 429.
Pisanite, 182.
Pisolite, 216.
Pistacite, 262.
Pitchblende, 169.
Pitkarandite, 295.
Pitticite, v. Iron Sinter.
Plagloclase, 275, 425.
Plagionite, 149.
Plasma, 237.
Plaster of Paris, 211.
Platinum, Native, 124.
GENERAL INDEX.
469
Platiniridium, 127.
Pleonaste, v. Spinel.
Plumbago, 107.
Plumbic oclire, 149.
Plumbogummite, 149.
Plumose mica, 267.
Polianite, v. Pyrolusite.
Polishing powder, 430.
Pollucite, Pollux, 254.
Polyargite, 312.
Polyargyrite, 120.
Polybasite, 120, 136.
Polycrase, 202.
Polyhalite, 205, 227.
Polylite, 246.
Polymignite, 202, 260.
Porcelain jasper, 442.
Porcelanyte, 442.
Porcellophite, 308.
Porfido verde antico, 452.
Porpezite, 127.
Porphyrite, 447.
Porphyritic structure, 415.
Porphyry, 417, 442, 448.
Antique green, 452.
Antique red, 415, 447.
Porphyryte, 447.
Portor, 431.
Potassium, Compounds of, 223.
Potstone, 304.
Potter's clay, 429.
Pozzuolana, 428.
Prase, 235.
Pregattite, 314.
Prehnite, 295.
Priceite, 212.
Prochlorite, 54, 319.
Propylyte, 447.
Protogine, 440.
Protovermiculite, 318.
Proustite, 119, 121.
Przibramite, 159.
Psammite, v. Sandstone.
Pseudomalachite, 139.
Pseudophite, 318.
Pseudotriplite, 191.
Psilomelane, 189.
Psittacinite, 139.
Pudding-stone, 426.
Purple copper, v. Bornite.
Pycnite, 287.
Pyrallolite, 295.
Pyrargillite, 315.
Pyrargyrite, 119, 121.
Pyreneite, 258.
Pyrite, 5, 6, 172.
Pyrites, Arsenical, 175.
Auriferous, 173.
Capillary, 164.
Cobalt, 164.
Cockscomb, 174.
Copper, 133.
Hepatic, 174.
Iron, 172.
Magnetic, 174.
Radiated, 174.
Spear, 174.
Variegated, 134.
White iron, 174.
Pyrochlore, 202, 214.
Pyrochroite, 189.
Pyrolusite, 188.
Pyromorphite, 151.
Pyrope, 258.
Pyrophosphorite, 214.
Pyrophyllite, 306.
slate, 455.
Pyrophyllyte, 455.
Pyrophysalite, 287.
Pyrosclerite, 317.
Pyrosmalite, 296.
Pyrostilpnite, 120.
Pyroxene, 245.
Pyroxenyte, 452.
Pyrrhopcecilon, 445.
Pyrrhosiderite, 182.
Pyrrhotite, 174.
Quartz, 53, 54, 58, 233, 238, 435.
andesyte, 447.
dioryte, 446.
felsyte, 443.
propylyte, 447.
syenyte, 445.
trachyte, 442.
Quartzyte, 435.
Quick lime, 217.
Quicksilver. See Mercury.
Raimondite, 182.
Realgar, 99.
Red antimony, 101.
chalk, 177.
copper ore, 136.
hematite, 176.
lead, 149.
470
GENERAL INDEX.
Red ochre, 167, 176.
silver ore, 119.
zinc ore, 155.
Reddingite, 191.
Redruthite, 132.
Refdanskite, 308.
Remingtonite, 168.
Rensselaerite, 305, 454.
Retinalite, 308.
Rhabdophane, 203.
Rh«tizite, 286.
Rhodium gold, 110.
Rhodizite, 206.
Rhodoehrome, 318.
Rhodochrosite, 191.
Rhodonite, 191, 247.
Rhodophyllite, 318.
Rhomb-spar, 219.
Rhyolyte, 418, fig. 8.
Ripidolite, 3,18.
Rittingerite, near Freieslebenite.
Rivotite, 139.
Rock cork, v. Hornblende.
crystal, 234.
meal, 216.
milk, 216.
salt, 224.
Rcepperite, 256.
Ro3sslerite, 207.
Rogersite, 203.
Romeine, Romeite, 214.
Roscoelite, 314.
Roselite, 168.
Rosite, 312.
Rosso antico, 415, 447.
Rothoffite, 258.
Rottisite, 168, 310.
Rubellite, 283.
Ruby, Spinel, 193.
Ruby -blende, v. Pyrargyrite, 119.
Ruby silver, 119.
Ruin marble, 431.
Ruthenium, Ores of, 127.
Rutherfordite, 203.
Rutile, 57, 162.
Safflorite, 165.
Sahlite, 246.
Sal ammoniac, 230.
Salmiak, 230.
Salt, Common, 29, 224.
Samarskite, 170, 202.
Sandstone, 426.
Sanidin, 278.
Saponite, 310.
Sapphire, 193.
Sarcolite, 269.
Sard, 236.
Sardonyx, 236.
Sartorite, 149.
Sassolitc, Sassolin, 97.
Satin-spar, 210, 215.
Saussurite, 263, 410, 449,
Saussurite group, 410.
Savite, v. Natrolite.
Scapolite, 268.
Scarbroite, 296.
Sceleretinite. 325
Scheelite, 212.
Schiller-spar, 309.
Schorl (pron. Shorl), 283.
Schorlomite, 292.
Schreibersite, 175.
Schrotterite, 296.
Scolecite, Scolezite, 299.
Scorodite, 185.
Scotiolite, 315.
Selenate, Copper, 135.
Lead, 150.
Selenide, Lead, 149.
Mercury, 149.
Silver, 118.
Selenite, 210.
Selenpalladite, 127.
Semiopal, 240.
Senarmontite, 101.
Sepiolite, 306.
Sericite, 314.
slate, 441.
Serpentine, 307, 454
Severite, 312.
Seybertite, 320.
Shale, 427.
Siderite, 185.
Siegenite, 164.
Silaonite, 102.
Silex, v. Quartz.
Silica, 233.
Silicate, Copper, 141, 142.
Lead, 153.
Nickel, 168.
Zinc, 157.
Silicates, 242.
Siliceous sinter, 240, 437.
slate, 436.
Silicined wood, 238.
GENERAL INDEX.
471
Silicoborocalcite, 212.
Sillimanite, 285.
Silt, 429.
Silver, 116, 121.
Compounds of, 216.
glance, 117.
Sinter, Siliceous, 240.
Sipylite, 202.
Sisserskite, 127.
Skutterudite, 166.
Smaltite, Smaltine, 165.
Smectite, 307, 312.
Smithsonite, 156.
Snow, crystals of, 4.
Soapstone, ^04, 454.
Soda nitre, 229.
Sodalite, 270.
Sodium, Compounds of, 223.
Sommite, 269.
Spaniolite, 136.
Spathic iron, 185.
Spear pyrites, 174.
Speckstein, v. Steatite.
Specular iron, 176, 455.
Speculum metal. 144.
Spelter, 158.
solder, 144.
Spessartite, 258.
Sphserosiderite, 186.
Sphalerite, 154.
Sphene, 290.
Spherocobaltite, 168.
Spilite, 451.
Spinel, 194, 204.
Spinthere, v. Titanite.
Spodumene, 248.
Stalactite, 216.
Stalagmite, 216, 432.
Stannite, 159.
Staurolite, Staurotide, 291.
Steatite, 304.
Steatyte, 454.
Stephanite, 119, 121.
Stercorite, 231.
Sterlingite, 0. Damourite.
Sternbergite, 118.
Stibnite, 100.
Stilbite, 302.
Stilpnomelane, 307.
Stinkstone, 217.
Stolpenite, 307.
Stolzite, 151.
Strakonitzite, 295.
Stratopeite, 316.
Strengite, 185.
Strigovite, 316.
Stromeyerite, 118.
Strontianite, 223.
Strontium, Compounds of, 220.
Struvite, 231.
Stubelite, 316.
Stylotypite, 136, 149.
Succinum, 325.
Sulphate, Aluminum, 197, 198.
Ammonium, 231.
Barium, 220.
Calcium, 210, 211.
Cobalt, 168.
Copper, 137, 138.
Iron, 182.
Lead, 150.
Magnesium, 205.
Nickel, 168.
Potassium, 227.
Sodium, 226, 227.
Strontium, 222.
Uranium, 171.
Zinc, 156.
Sulphide, Antimony, 100.
Arsenic, 99.
Bismuth, 102. v.
Cadmium, 159.
Cobalt, 164.
Copper, 132, 133, 134. -
Iron, 172, 174.
Lead, 145, 149.
Manganese, 188.
Mercury, 128, 130.
Molybdenum, 96.
Nickel, 164.
Ruthenium, 127.
Silver, 117, 118.
Tin, 159.
Zinc, 154, 155.
Sulphur, Native, 37, 94.
Sulphuret, see Sulphide.
Sulphuric acid, 96.
Sulphurous acid, 96.
Sunstone, 277, 279.
Susannite — Rhoinbohedral Lead*
hillite.
Sussexite, 206.
Syenites, 445.
Syenyte, 445.
gneiss, 446.
Sylvanite, 116, 118.
473
GENERAL INDEX.
Sylvine, Sylvite, 224.
Syngenite, 227.
Szaibelyte, 206.
Tabasheer, 241.
Tabular spar, 244.
Tachhydrite, 205.
Tachyaphaltite, 260.
Tachylyte, 452.
Tagilite, 139.
Talc, 304.
Talcose schist, 454.
slate, 441.
Tantalates, 170, 184, 202, 214
Tantalite, 184.
Tapalpite, 118.
Tasmanite, 326.
Tellurate, Bismuth, 102.
Mercury, 129.
Telluride, Bismuth, 102.
Gold, 115, 116, 118.
Lead, 149.
Mercury, 129.
Silver, 118.
Tellurite, 96.
Tellurium, Bismuthic, 102.
Foliated, ro. Nagyagite.
GrJ'Mc, 118.
Native, 9(3.
Tellurous acid, 96.
Tengerite, 203.
Tennantite, 135.
Tenorite, 137.
Tephrpite, 256.
Terenite, 312.
Teschemacherite, 231.
Teschenite, 448.
Tetradymite, 102.
Tetrahedrite, 121, 135.
Thenardite, 227.
Thermonatrite, 230.
Thomsenolite, 197.
Thomsonite, 298.
Thorite, 296.
Thraulite, 316.
Thulite, 263.
Tlmmite, 264.
Thuringite, 319.
Tiemannite, 129.
Tile ore, 137, 160.
Till, 429.
Tin, Native, 159.
Tin ore, Tin stone, 160.
Tin pyrites, 159.
Tinkal, 227.
Titanic iron, 178, 456.
Titanite, 290.
Titanium, Ores of, 162.
Tiza, v. Ulexite.
Tocornalite, 121.
Tonalyte, 447.
Topaz, 286.
False, 235.
Oriental, 193.
Topazolite, 258.
Torbanite, 325, 329.
Torbernite, 170, 139.
Touchstone, 237.
Tourmaline, 282.
Trachydoleryte, 447.
Trachyte, 442.
Tractolyte, 450.
Trap, 451.
Traversellite, 295.
Travertine, 432.
Tremolite, 249.
Trichites, 416.
Triclasite, 315.
Tridymite, 88, 241.
Tripestone, 212.
Triphylite, Triphyline, 184, 190.
Triplite, 191.
Triploidite, 191.
Tripolite, 241.
Tsipolyte, 430.
Tritomite, 296.
Tro'gerite, 171.
Troilite, 175.
Trona, 230.
Troostite, 157.
Tscheffkinite, 203, 291.
Tschermakite, v. Oligoclase.
Tschermigite, 198, 231.
Tufa, Tuffe, 428.
Tufa, Calcareous, 216.
Tungstate, Copper, 138.
Iron, 183.
Lead, 151.
Lime, 212.
Tungstic ochre, 97.
Tungstite, 97.
Turgite, 182.
Turquois, 200.
Tyrolite, 139.
Ulexite, 212.
GENERAL INDEX.
473
Ullmannite, 166.
Ultramarine, 270.
Unakyte, 440.
Unghwarite, 307.
Unionite, v. Zoisite.
Uraconise, Uraconite, 171.
Uralite, 247.
Uranin, Uraninite, 169.
Uranite, 170.
Uranium, Ores of, 169.
Uranmica, 170.
Uranoclialcite, 171.
Uranocircite, 171.
Uranospinite, 170.
Uranotantalite, 170.
Uranvitriol, 171.
Urpethite, 334.
Valentinite, 101.
Vanadate, Copper, 139.
Lead, 152.
Vanadinite, 152.
Variolyte, 449.
Variscite, 200.
Vauquelinite, 151.
Velvet copper ore, 138.
Venerite, 319.
Venice white, 221.
Verd-antique, 308, 454.
Oriental, 415.
Verde di Corsica duro, 449,
Vermiculite, 317.
Vermilion, 129.
Vesuvianite, 261.
Veszelyte, 139.
Villarsite, 296.
Viridite, 317.
Vitreous copper, 133.
silver, 117.
Vitriol, Blue, 137.
Green, 182.
Iron, 182.
White, 156.
Vivianite, 184.
Voglianite, 171.
Voglite, 171.
Volborthite, 139.
Volknerite, 194.
Voltaite, 182.
Voltzite, 155.
Vorhauserite, 308.
Vulpinite, 212.
Wacke, 428.
Wad, 190.
Wagnerite, 206.
Walchowite, 325.
Walpurgite, 171.
Warringtonite, «. Brochantite.
Warwickite, 206.
Washingtonite, 178.
Water, 4, 231.
Wavellite, 201.
Websterite, 199.
Wehrlite, 102.
Wernerite, 268.
Westanite, v. Fibrolite.
Wheel-ore, 136.
Whetstone, 436, 453.
White vitriol, 156.
arsenic, 99.
Whitneyite, 135.
Wichtine, Wichtisite, 252.
Willcoxite, 320.
Willemite, 157, 256.
Williamsite, 308.
Wilsonite, 312.
Winkworthite, v. Howlite.
Witherite, 221.
Wittichenite = Cu3BiS3.
Wittingite, 316.
Wohlerite, 256, 260.
Wolfram, Wolframite, 183.
Wollastonite, 244.
Wollongongite, 326.
Wood-opal, 240.
Wood tin, 160.
Woodwardite, near Cyantrochite.
Wulfenite, 151.
Wurtzite, 155.
Xanthophyllite, 320.
Xanthosiderite, 182.
Xenotime, 203.
Xylotine, 295.
Yenite, 263.
Youngite, 155.
Ytter-garnet, 258.
Yttrium ores, 201.
Yttrocerite, 201.
Yttroilmenite, 170.
Yttrotantalite, 202,
Zaffre, 168.
474
GENERAL INDEX.
Zaratite, 168.
Zeagonite, 296.
Zeolite Section, 297.
Zepharovichite, 201.
Zeunerite, 170.
Zietiisikite, 324.
Zinc, ores of, 154.
blende, 154.
bloom, v. Hydrozincite.
Zinc ore, red, 155.
Zmcite, 155.
Zinkenite, 149.
Zinnwaldite, 268.
Zippeite, 171.
Zircon, 259.
Zirconite, 260.
Zircon-syenyte, 446.
Zoblitzite, 809.
Zoisite, 263.
Zonochlorite, 296.
Zorgite, 149.
Zwieselite, v. Triplite.
MINERALOGY-METALLURGY-ASSAYING, ftc,, ftc.
JOHN WILEY & SONS, 15 Astor Place, New York,
PUBLISH
I.
A SYSTEM OF1 MINERALOGY— DESCRIPTIVE MINERALOGY,
comprising the most recent discoveries. By James Dwight Dana, Prof,
of Geology and Mineralogy, Yale College, aided by Prof. George Jarvis
Brush, of Sheffield Scientific School. Fifth edition, re-written and en-
larged. Illustrated with upwards of 600 wood-cuts. Thick 8vo,
cloth, including three Appendixes complete to 1882 $10.00
This work contains full descriptions, physical, chemical and geographical, of
all known minerals up to the time of publication. Besides giving the composition
of minerals at length, it includes all the analyses that had been made from the first
beginning of analytical chemistry, along with references to their authors, and the
works or memoirs in which they appeared. It also gives, under each species, de-
tailed statements of the blowpipe characters of each, prepared by Prof. Brush,
extended notices of Foreign, as well as American localities— the latter with special
f ullness as regards modes of occurence and associated minerals,— and a complete
historical account of the names of minerals and their varieties, and of all syno-
nyms.
The volume, as now Issued, includes three appendixes : the first, prepared
"by Prof. G J. Brush, and the second and third by &r. E. S. Dana, bringing the
subject down, as regards new species, and new determinations of the old, to the
date of publication, in 1883.
II.
MANUAL OF DETERMINATIVE MINERALOGY, with an intro-
duction on BLOWPIPE ANALYSIS. By George J. Brush, Professor of
Mineralogy in the Sheffield Scientific School of Yale College. Third
edition, revised and corrected, with NEW NOTATION. 8vo, cloth, $3.50
The method of instruction adopted in this work is first to give the student a
preliminary knowledge of the use of the blowpipe and other apparatus employed
in the determination of minerals. It includes a systematic course of Qualitative
Blowpipe Analysis, with tables of reactions of the metals, metallic oxides, and
earths with and without fluxes, concluding with an alphabetical list of elements
and compounds, with their characteristic blowpipe and other reactions. This is
followed by tables for the determination of mineral species, which are so arranged
that by means of a few simple experiments before the blowpipe and in the wet
way, the mineral is quickly limited to a group of a few species ; among the mem-
bers of this group the mineral is distinguished by other trials, and when from these
various experiments the mineral species is finally decided upon, the conclusion is
confirmed or corrected by reference to the chemical composition, crystalline form
and other physical characteristics given in the tables.
An acquaintance with the use of the blowpipe, such as is gained by the study of
the introductory pages, and with the manner of performing the simplest opera-
tions of solution and precipitation, is all that is necessary in making the requisite
trials.
These determinative tables, while founded upon the tenth edition of Professor
Von Kobell's well-known work, are arranged in an entirely new form, much more
convenient for use, and contain, besides, a large amount of additional matter in
regard to old, as well as new, mineral species.
The Same work— Second Edition— OLD NOTATION. 8vo, cloth $2.50
III.
A TEXT-BOOK OF MINERALOGY. With an extended treatise on
CRYSTALLOGRAPHY and PHYSICAL MINERALOGY. By Edward S. Dana,
Curator of Mineralogy, Yale College, on the plan and with the co-opera-
tion of Prof. James D. Dana. Illustrated with upwards of 800 wood-
cuts and one colored plate. New revised edition, 1883. 8vo, cloth. $3.50
This work is especially designed for those who desire to make themselves
acquainted with the principles and methods of Crystallography, and of the no less
important branch of Optical Mineralogy. With this end in view, about one-haif
of the whole work, which covers nearly 500 pages, is devoted to these subjects, and
the remainder is given to the description of mineral species.
The system of Crystallography adopted is that of Naumann, which has the
great advantage of being most readily intelligible to the beginner. The six crys-
talline systems are taken up in succession, and the forms occurring under each,
with their symbols, are described, and numerous figures are added as illustrations
of the text. The methods of Mathematical Crystallography are then explained,
and the application of them to all the ordinarily occurring cases given in full, so
that any one with a knowledge of ordinary trigonometry can soon learn to make
all necessary calculations. This subject closes with a chapter on the measurements
of crystals, and others on twin crystals, the irregularities of crystals, crystalline
aggregates, and pseudomorphous crystals.
Supplementary to this portion of the work, there is given in the Appendix, a
chapter upon Miller's System of Crystallography, in which its principles and
methods are clearly and concisely stated, and another upon the methods of draw-
ing crystals.
In the description of the physical characters of minerals, their distinguishing
optical properties are developed with especial fullness, preceded by a statement of
the fundamental principles of Optics upon which they depend, and a description
of the instruments used in the research. A colored plate in the beginning of the
volume shows the interference-figures observed when sections of different biaxial
crystals are viewed in polarized light.
The section on Chemical Mineralogy also includes a brief description of the
methods of blowpipe analysis, and a table for the determination of minerals based
upon these is given in the Appendix.
The descriptions of mineral species cover about 200 pages ; all species known
up to the date of publication are included, but only those of the most importance
are described at length.
In addition to the chapters in the Appendix already alluded to, a fourth con-
tains a catalogue of American localities of minerals.
IV.
MANUAL OP MINERALOGY AND LITHOLOGY. Containing ele.
ments of the science of Minerals and Rocks, for the use of the practical
Mineralogist and Geologist, and for instruction in Schools and Colleges.
By Professor James D. Dana, of Yale College. New edition, revised
and re-written. 12mo, cloth $2.00
The prominent feature of this Manual is its arrangement of the ores under the
head of the metals they yield. It is thus especially adapted to the wants of those
interested practically in minerals, and also of Mineralogists not versed in chemistry.
The work contains an account of the elements of Crystallography, and of the
physical and chemical departments of Mineralogy ; descriptions of mineral species,
but with only brief notices of the less important kinds ; a full table of American
localities of minerals ; and a table for the determination of minerals. The subject
of Hooks is treated with considerable detail, all the kinds of rocks with their
prominent varieties being described, and the principles of the Science of Litno^-gy
simply though brieiiy explained and illustratc-a.
V.
A PRACTICAL TREATISE ON METALLURGY. Adapted from the
last German edition of Prof. Kerl's Metallurgy. By William Crookes
and Ernst Rohrig. In three vols., thick 8vo. Price .......... $30.00
Separately. Vol. 1. Lead, Silver, Zinc, Cadmium, Tin, Mercury, Bis-
muth, Antimony, Nickel, Arsenic, Gold, Platinum, and Sulphur $10.00
Vol. 2. Copper and Iron ................................... 10.00
Vol. 3. Steel, Fuel, and Supplement ....................... 10.00
VL
THE CALCULATIONS OF STRENGTH AND DIMENSIONS OF
IRON AND STEEL CONSTRUCTIONS. With reference to the
latest experiments. By Prof. J. J. Weyrauch, of Polytechnic Insti-
tute of Stuttgart. Translated by A. J. Du Bois. 8vo, cloth, with
plates ....................................................... $1.50
VII.
IRON SMELTERS' POCKET ANALYSIS BOOK. By Thomas Whit-
well. Containing Tables and Blanks for Analysis of Ores, Coal, Coke,
Limestone, Iron, Steel, Slag, Bricks or Clay, with Tables of Specific
Gravities, &c. , &c. Oblong morocco, pocket size ................ $2.00
VIII.
A TREATISE ON THE ASSAYING OF LEAD, SILVER, COPPER,
GOLD AND MERCURY. By Bodeman & Kerl. Translated by
W. A. Goodyear. 12mo, cloth ................................ $2.50
IX.
A MANUAL OF PRACTICAL ASSAYING. By John Mitchell.
Fifth edition, edited by William Crookes. With numerous plates.
Thick 8vo, cloth ............................................. $10. 00
NOTES ON ASSAYING AND ASSAY SCHEMES. By P. De Peyster
Ricketts, E.M., Ph.D., of School of Mines, Columbia College, N. Y.
New edition, revised with additions. 8vo, cloth ................ $3.00
*** These Text-Books will be supplied to SCHOOLS and COLLEGES at 20 per cent.
discount from the printed prices.
TEACHERS and PROFESSORS may have single copies for examination, with ref-
erence to introduction, at a discount of one-third, and they will be prepaid by
mail on the receipt of the price.
RETURN
EARTH SCIENCES LIBRARY
642-2997
LOAN PERIOD 1
1 MONTH
2
3
4
5
6
ALL BOOKS MAY BE RECALLED AFTER 7 DAYS
Books needed for class reserve are subject to immediate recal
DUE AS STAMPED BELOW
FORM NO. DD8
UNIVERSITY OF CALIFORNIA, BERKELEY
BERKELEY, CA 94720
I
U.C.BERKELEY LIBRARIES
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11