Geol ogy
The Mineralogy of Arizona
BY
F. N. GUILD
Professor of Chemistry and Mineralogy, University of Arizona
EASTON, PA.
THE CHEMICAL PUBLISHING CO.
1910
LONDON, ENGLAND:
WILLIAMS & NORGATE
14 HENRIETTA STREET, COVENT GARDEN, W. D.
COPYRIGHT, 1910, BY EDWARD HART
INTRODUCTION
It is well known to students of mineralogy that the greater num-
ber of interesting minerals are found at some depth below the
surface in regions where the destructive effect of erosion and the
decomposing action of meteoric water are not active and hence can
be reached only by expensive exploitation rarely undertaken ex-
cept when compensation is hoped for. in the possible discovery of
the precious or useful metals. Arizona is attracting considerable
attention on account of its unusual mineral resources, and its
mountains and canons are filled with excavations which are evi-
dences of the enthusiasm with which the search is carried on.
Thus formations are penetrated and minerals exposed to view
which, lacking this incentive, would never have been discovered.
In certain respects many of the minerals in Arizona are suffi-
ciently unusual in their mode of occurrence and in their composi-
tion to warrant special attention. The rather common occurrence
of vanadium, tungsten and molybdenum, associated with deposits
of economic value, has been the subject of frequent mention in the
scientific journals. These are of great interest, not only from the
variety and beauty of the crystallizations presented, but, contain-
ing as they do, elements of considerable rarity, because the chem-
ical and geological conditions which have given rise to them de-
mand investigation. The object of this publication, then, is to
give a fairly complete description of Arizona's minerals with some
reference to their mode of occurrence, associations and chemical
composition. The order of treatment is in accordance with the
well known classification of Dana. The elements found as min-
erals are considered first ; then the sulphides and others, as out-
lined in the following table.
819491
CLASSIFICATION AND ORDER OF TREATMENT
PAGE
I. Native Elements 5
II. Sulphides, Arsenides, Etc 23
III. Sulpho-salts, Sulpharsenites, Etc. 31
IV. Chlorides, Fluorides, Bromides, Etc. 33
V. Oxides 36
VI. Oxygen Salts 46
1 i) Carbonates 46
(2) Silicates 56
(3) Phosphates, Vanadates, Etc 73
(4) Sulphates < 83
(5) Tungstates and Molybdates 92
VII. New Minerals Discovered in Arizona 97
I. NATIVE ELEMENTS
Diamond, C
Composition and Artificial Production. The diamond
is crystallized carbon not different in its chemical com-
position from pure charcoal. Because of the simplicity
of its composition, attempts have repeatedly been made
in chemical laboratories to produce it. The method of
investigation usually consists in dissolving carbon in
molton iron or similar media, and allowing it to crystal-
lize while cooling. Until recently all such attempts
have failed, owing to the habit of carbon to crystallize in
the form of graphite rather than in its other possible
form, the diamond. Moisson, however, succeeded in
producing the diamond by heating iron in which
carbon was dissolved to a temperature of 3000 C. by
means of an electric furnace, and suddenly cooling the
mass by plunging it into cold water. By this simple
method a cold solid shell was formed, which on contract-
ing, subjected the remaining liquid mass to enormous
pressure. Under these extraordinary conditions a part
of the carbon crystallized in the form of diamond.
The product, however, was too small and in crystals too
imperfect to warrant much hope that by this means
diamonds of sufficient size and brilliancy could be pro-
duced to serve as gems. 1 These investigations, together
with the researches on meteorites described below, sug-
i Comptes rendus de T Academic des Sciences. 116, 218.
6 THE MINERALOGY OF ARIZONA
gest a possible origin of the gem in nature, the factors
in its formation being a solution of carbon in a basic
magma and high pressure.
Terrestrial Diamond. Although diamonds have been
found in many of the states, notably in North Carolina,
Virginia, Oregon, California and Wisconsin, Arizona has
yet to report an authentic discovery of this valuable gem
mineral. In 1870, however, a company was organized
for the exploitation of diamonds and other gems in
Arizona and New Mexico. It is said that 80,000 carats
of so-called rubies and many diamonds purporting to
have been collected from these fields, were displayed to
prospective stock buyers. Expeditions to the locality
were made, and in a week's time as many as 6,000 carats
of rubies and 1,000 carats of diamonds are said to have
been gathered. Finally, Mr. Clarence King, then Direct-
or of the United States Geological Survey, made a trip
to these famous gem fields, and succeeded in bringing to
light the fact that an American had actually purchased
in London a large quantity of rough diamonds with
which the deposit had been salted ; salted, in fact, so
thoroughly that an occasional diamond was picked up in
this district even several years after the event. 1 The in-
cident is well characterized by Hintze in his Handbuch
der Mineralogie as a " grossartige Schwindel."
Diamonds are most frequently associated with perido-
tites, serpentines and other ultra-basic rocks, or the
debris accompanying such rocks, a fact that should be
borne in mind by the mineralogist or miner while search-
1 Kunz : Gems, p. 36.
NATIVE ELEMENTS 7
ing for these gems. The recent discovery of diamonds
in Arkansas, where they are found in peridotitic rock
material similar to the South African fields, is a good
illustration of this very characteristic mode of occurrence.
These types of rocks, though not abundant in Arizona,
are present in certain localities, and they might well be
the subject of special research for these gems as well as
other minerals known to occur associated with them.
Meteoric Diamond. The presence of crystallized car-
bon or the diamond in meteoric iron was first proved by
Jerofejew and Latschnow, in 1888, in their investigations
of the meteor which fell in Nowo-Urei, Krasnoslobodsk,
Russia, on the 22d day of September, 1886. Since that
time the diamond has been found in meteoric iron in
widely different localities, but notably, perhaps, in the
Canon Diablo specimens found near Coon Mountain, or
Crater Mountain, in the northern part of Arizona.
Papers on the subject of diamonds in these meteoric
masses have appeared by Foote and Koenig, 1 by Hunting-
ton and Kunz, by Friedel, 2 by Cohen, and by others.
Moisson, in his researches on the artificial production of
the diamond in the electric furnace, directed special at-
tention to the occurrence of this mineral in the Arizona
meteorites. Some of the crystals obtained by him meas-
ured 0.7 by 0.3 millimeters. They were yellow in tint,
of rough surface, and transparent. 3
1 Am. Jour. Sci., 1891, 43, 413.
2 Bui. Soc. Min., Paris, 1892, 15, 285.
* Moisson : I<e Four IJlectrique, p. 140.
8 THE MINERALOGY OF ARIZONA
Graphite, C
So far as the writer knows, pure graphite has not been
found in Arizona. A black, graphite-like clay is found
in large quantities near Benson, and will be described
under Graphitic Clay.
Seams of what appeared to be impure graphite in black
carbon shales have frequently been observed, but no
analyses have been made.
Sulphur, S
Sulphur has been found in very small quantities in
some of the crater cones near Sunset Peak, in the San
Francisco mountains near Flagstaff. Abundant silicious
sinter occurs here, showing that a solfataric period fol-
lowed the more active stages of vulcanism. The sinter
is frequently of a pure sulphur yellow tint and has been
mistaken by many tourists for sulphur.
Arsenic, As
Attention has recently been called to an interesting
occurrence of this element in Washington Camp, Santa
Cruz County. 1 Here it occurs in reniform masses, some-
times several pounds in weight attached to the walls of a
small pocket in dolomitic limestone. The latter is highly
metamorphic and crossed by veins carrying lead, copper
and zinc minerals. Intrusive rocks are abundant in the
district and are considered to be concerned in some way
with the mineralization of the limestone. The action
especially concerned with the deposition of the arsenic is
supposed to be fumerolic.
1 C. H. Warren : Amer. Jour. Sci., 4th series, 16, 337.
NATIVE) ELEMENTS 9
Gold, Au
As is well known, native gold occurs in many localities
in Arizona both as placer deposits and vein formations.
Nuggets of, the value of $400.00 each have been taken
from the Weaver placers. 1 Other well known placers are
those of Graterville, Canada del Oro in the Catalina
mountains, L,inx Creek near Prescott, etc. A description
of these deposits, as well as of the gold veins of Arizona,
would appear more properly, perhaps, in a publication
on mines than in one on mineralogy. A few rather in-
teresting modes of occurrence may, however, be men-
tioned.
Native Gold in Igneous Rocks. An unusual occurrence
of this kind was recently called to the writers attention
by Mr. G. W. Maynard, a mining engineer of New York
City. The gold is found in thin paper-like incrustations
in the fine cracks of a rhyolitic rock, which occurs on
the northeast slopes of the Catalina mountains, near
Tucson. The rock is somewhat brecciated in places, the
fragments, also rhyolite (felsite), being partially digested
by the magma. The rock, when crushed and panned,
shows a distinct color of gold, but analyses never give
more than a trace of the precious metal. Mr. G. P.
Merrill 2 and W. P. Blake 3 have described the occurrence
of gold in granite, and Mr. Moericke* its occurrence in a
trachitic rock. In all of these cases the gold seems to be
1 W. P. Blake : Rep to Gov., 1899.
2 Am. Jour. Sci., 4th series, i, p. 309.
3 Am. In. Min. Eng., 26, 290.
* Tschermaks : Min. u. Pet. Mit., Ill, 1891.
IO THE MINERALOGY OH ARIZONA
primary, sometimes embedded and even completely en-
veloped in crystals of quartz and feldspar. In the rocks
of the Catalina mountains it would seem quite probable
that the gold is secondary, having been deposited in the
minute cracks by percolating solutions. Quite likely the
gold originally existed in the eruptive but in such minute
quantities that it could be detected only after the
concentration described above had taken place. The
writer has frequently observed similar superficial min-
eralization along joint planes, especially in the case
of copper where the country rock has become quite deeply
stained. These have often led to expensive and useless
exploitations.
Gold in Crystallized Calcite. Some years ago a small
sample of vein material was received by the writer from
the Vekol mining district which consisted chiefly of
white quartz and cleavage masses of calcite. Embedded
in the latter were several small grains of gold about two
millimeters in diameter. It might at first seem that the
gold had been formed by the same processes and at the
same time as the calcite. A closer inspection, however,
showed that the grains of gold were in reality attached
to quartz and were projecting into a cavity, which later
became filled with the enclosing calcite.
Gold in Cerussite. This unusual mode of occurrence
has been observed in specimens from Oro Blanco. One
large sample, weighing several pounds and consisting al-
most entirely of cerussite, was found to contain nearly
one ounce of gold per ton. The gold was in a very fine-
NATIVE ELEMENTS n
ly divided state and could rarely be seen even by the aid
of a hand lens. The association being so intimate in this
case one is inclined to look upon the gold as having been
deposited at the same time and under identical conditions
as the carbonate, although it is usually held that gold is
not deposited from the same media as those which give rise
to lead minerals, especially lead minerals occurring in the
oxidized zone. Even where lead minerals are found in
the same deposit as gold, the gold is usually either in the
gangue or in some accessory mineral. This is well illus-
trated in the ores from the Elkhart mine, near Chloride,
Mohave Co. , Arizona. The chief minerals found here
are quartz gangue, galena and pyrite, and the ore is
worked chiefly for its values in gold and silver. Silver
is found to accompany the galena and gold the iron
pyrite.
Silver, Ag
Native silver has been found in the Silver King mine,
Final Co., and in small quantities associated with argen-
tiferous ores, in other mines of the State.
Copper, Cu
Native copper is frequently found in the zone of oxide
enrichment in many of the copper mines of the State.
It is especially abundant at Bisbee, in the Copper
Queen mines, the Shattuck, and others, where it occurs
in sheets, nodules and aborescent growths associated with
cuprite, kaolin, calcite, limonite, and other minerals. It
is interesting to note that in the Holbrook shaft, espec-
ially in the neighborhood of the 400 ft. level, the ore
12 THE MINERALOGY OF ARIZONA
lenses contain considerable chalcocite. These have fre-
quently become oxidized only on their margins. This
has become a guide to the miners, and when striking na-
tive copper after driving through barren ground, they
know they are about to reach a rich ore shoot. When
they are in ore and strike native copper they believe that
they are near the end of the rich deposit. A large sample
of native copper presented to the University, by Dr. H.
W. Fenner, of Tucson, shows delicate sponge-like forms
consisting of aborescent masses altered superficially to
malachite. Another interesting mode of occurrence ob-
served in situ by the mining class of the University while
on one of its annual trips, was that of delicate mosslike
masses containing embedded rhombs of calcite of almost
perfect development. In the mines of Cananea, Mexico,
the mode of occurrence is somewhat different. Here the
native copper is found in thin sheets and slabs between
the fracture planes in brecciated quartzite, and is not so
often associated with the other enrichment minerals of
copper.
Native Copper in Epidote. Many of the copper deposits
of Arizona are in a contact zone associated with garnet,
epidote, and other minerals characteristic of contact
metamorphism. It is not often, however, that the min-
erals of copper, and especially native copper, appear in
the same hand specimen as the contact minerals men-
tioned above. Samples showing this intimate association
have been received at the University from two distinct
localities, one from the northern part of the State,
NATIVE ELEMENTS 13
the exact place unknown, and the other from the Santa
Rita mountains, south of Tucson. The two samples
were almost identical in appearance. They were made
up of hard, compact epidote of the characteristic yellow
color, and in places contained as many as forty or fifty
brilliant grains of copper to one square inch of surface.
These vary in size from a fraction of a millimeter to two
or three millimeters in diameter. The epidote from the
Santa Rita locality is slightly altered by the infiltration
of both calcite and silica. It may be possible that the
presence of the copper is due to the same secondary
action.
Native Copper in a Trap Rock. Although this mode
of occurrence has been observed only in case of a dike
found in Sonora, Mexico, it is considered of sufficient in-
terest at this point to warrant a brief description. The
rock is found near Washington Camp, Arizona, only a
few hundred feet from the Mexican line. It is quite un-
decomposed in appearance. Fresh fractures show it to
be a dark colored, almost black eruptive, presenting in
places the characteristic orphitic structure of the diabases.
The rock is crossed by many small fracture planes, along
which remarkably slight alteration has taken place. Yet
it is along these planes that the copper appears as thin
paper-like fillings and aborescent incrustations, giving
the surface of the rock as it is broken open a metallic,
moss-like appearance. Under the petrographic micro-
scope, the rock is found to be a quite typical diabase,
with orphitic structure fairly well developed, with the
14 THE MINERALOGY OF ARIZONA
exception that the feldspars contain numerous and re-
markably large inclusions of the pyroxenes. The latter
mineral is but slightly altered to chlorite, while the feld-
spars are sufficiently fresh to show the characteristic
polysynthetic twinning of the plagioclases. The copper
appears as small bunches and in thin threads, which
sometimes nearly cross the field of the microscope.
These are, of course, cross sections of the fracture planes
mentioned above. The threads are sometimes not more
than 0.02 millimeters in width and several millimeters in
length. The copper has evidently been brought in and
deposited by solutions which have not materially affected
the rock through which they passed. The metal may
have been derived from other portions of the dike, or
more probably from other mineralized rocks in the
vicinity.
Platinum, Pt
Traces of this metal have been reported by the United
Geological Survey, 1 in a sample of black sand from near
Prescott, and in another sample of the same material from
near Columbia. At the University of Arizona several
samples of supposed platinum ore have been investigated,
but always with negative results.
Iron, Fe.
Native iron is not often found as an original con-
stituent of the earth's crust. It has been observed, how-
ever, in nearly every part of the world in the form of
meteoric iron. These fragments are simply inter-planetary
1 Mineral Resources, 1905.
NATIVE; EI,EMENTS 15
particles which the earth picks up during its journey
through space. These particles have been seen to strike
the earth and having been examined before they have
had time to become cold, there is no doubt as to their
immediate origin. It is claimed 1 that during every 24
hours the earth encounters many millions of these frag-
ments, and, were it not for the protecting influence of our
atmosphere, the vegetation and animal life would soon
be destroyed owing to the continual impact of these mi-
nute projectiles. The atmosphere serves as a protecting
medium through which these minute bodies are unable
to pass without becoming thoroughly disintegrated into
a fine dust, due to the high temperature caused by friction.
Though very few of them ever reach the earth in a
compact form, yet the weight of our planet is yearly in-
creasing at the rate of a few tons as a result of these ad-
ditions. Indeed, it is even believed by many geologists
that our planet and the other heavenly bodies owe their
origin to this source rather than to a central molten or
gaseous mass which by centrifugal action has suc-
cessively thrown off masses that have developed into
planets, moons, etc.
The Tuscon Meteorites. Two important masses of
meteoric iron have been discovered in the vicinity of
Tucson, but thoroughly reliable data as to the exact
point where they fell seem to be lacking. The majority
of the reports mention the Santa Rita mountains, south
of Tucson, as the original locality, while a few author-
ities refer to the fall as having taken place in the ' 'Santa
1 Todd : New Astronomy, p. 412.
l6 THE MINERALOGY OF ARIZONA
Catarina" mountains north of Tucson. The fact that
Mexico is sometimes mentioned is to be expected since
at that time Tucson and vicinity were a part of that
country.
According to Mr. L,. Fletcher 1 the attention of the
scientific world was first called to these meteorites through
Fig. i. The Tucson Ring Meteorite as originally seen in a blacksmith
shop in Tucson, where it was employed as an anvil.
(Drawn by Geo. Nishihara from an old wood cut in Bartlett's
Explorations, Vol. II, 1854.)
the verbal report of the entomologist, Dr. J. L,. I,eConte
of Philadelphia, at a meeting of the American Association
for the Advancement of Science held at Albany in
August, 1 85 1 . He reported that ' 'while passing through
the village of Tucson in the proceeding February, he had
observed two large pieces of meteoric iron used by the
1 The Meteoric Iron of Tucson, Mineralogical Magazine, 9, No. 41, p. 16.
NATIVE; EI^MSNTS 17
blacksmiths of the town as anvils.' 1 The blacksmiths
were reported as having been very persistent in not al-
lowing him to chip off fragments for further examination
stating that in a certain canon in the immediate vicinity
the fragments were so abundant that many samples could
easily be obtained.
In 1854, Professor Shepard 1 gave a brief account of
these meteorites, in which he states that according to in-
formations furnished him, they were found in a canon
of the Santa Rita mountains, about 25 or 30 miles south
of Tucson. Both were reported as being used as anvils,
and one was described as being of a peculiar annular
form. About this time also, samples were analyzed by
Professor Lawrence Smith 2 and others.
In 1857, Dr. Irwin, Surgeon of the United States
Army, found the ring meteorite in one of the streets of
Tucson and took possession of it with the intention of
placing it in the Smithsonian Institution. It was started
on its journey in 1860, and after traveling to Guaymas,
Mexico, then to San Francisco, finally reached Washing-
ton in 1863, by way of the Isthmus of Panama. Dr. Irwin
states that it was considered by the inhabitants of Tucson
at that time to have come from the ' 'Catarina' ' mountains,
and further, that it was believed a meteoric shower had
taken place there about 200 years ago. 3 It would seem,
however, as explained by Mr. Fletcher, that the term
"Catarina" was loosely applied, and that Dr. Irwin was
thus misinformed as to the real locality.
1 Am. Jour. Sci., 2d series, 18, p. 369.
2 Am. Tour. Sci., 2d series, 19, p. 161.
8 Smithsonian Report, 1863, and Fletcher : Min. Mag., 9, No. 41.
l8 THE MINERALOGY OF ARIZONA
The dimensions of the annular meteorite, or Irwin
Iron, as it is sometimes called, still to be found in the
Museum at Washington, are given by Whitney, as
follows :
Greatest exterior diameter 49 in.
Least exterior diameter 38 in.
Greatest width of central opening 26^ in.
Least width of central opening 23 in.
Greatest thickness at right angles to plane of
ring 10 in .
Width of thickest part of ring 17 j in.
Width of narrowest part 2^ in.
Weight 1,400 Ibs.
This fragment is further known as the Tucson Meteor-
ite, the Signet, the Ring Meteorite, the Ainsa, the
Muchacho, etc.
The other fragment from Tucson was of the shape of
an elongated flattened slab. Its length was 49 inches,
average breadth 18 inches, and varying in thickness from
2 to 5 inches. Its weight was determined to be 632 Ibs. 1
It was taken possession of by Gen. Carleton and sent to
San Francisco. Hence it is known in Mineralogical liter-
ature as the Carleton Meteorite.
As a result of the investigations on polished surfaces
of these two meteoric masses, it is generally believed
that they were portions of the same mass, or at least both
were members of the same meteoric shower.
The chemical composition is illustrated by the follow-
ing analyses : 2
1 Proc. Cal. Ac. Nat. Sci., 1863, 3, pt. i, p. 49.
2 Quoted from Min. Mag., 9, No. 41.
NATIVE ELEMENTS IQ
Smith Genth Brush
Per cent. Per cent. Per cent.
Fe 85.54 83.47 81.65
Ni 8.55 9.44 9-17
Co 0.61 0.42 0.44
Cu 0.03 0.008 0.08
P 0.12 o.io 0.49
A1 2 O 3 Trace Trace Trace
CaO 0.46 1.16
MgO 2.04 2.59 243
Cr 2 O 3 0.21
SiO 2 3.02 2.89 2.63
From these analyses it appears that the meteorites are
mostly nickel iron, with small quantities of olivine,
schreibersite and chromite.
An excellent model of the ring meteorite has recently
(July, 1907), been received from Washington, and can
be seen at the Museum of the University of Arizona.
Canon Diablo Iron. One of the most famous occur-
rences of meteoric iron in the world is that of the Canon
Diablo iron, found in the immediate vicinity of a slight
elevation, variously known as Crater Mountain, Coon
Butte, and Meteor Mountain. It is located in the
plateau region of Arizona, about twelve miles from the
Santa Fe station, known as Canon Diablo, and thirty-five
miles from Flagstaff. The iron is found in fragments
scattered on the surface of the ground in sizes varying
from that of a bean to masses weighing over one hundred
pounds. In all it is said that nearly twenty tons of the
material have been gathered and distributed to various
museums and private collections in all parts of the world.
Occasionally, as many as thirty fragments may be picked
2O THE MINERALOGY OF ARIZONA
up by one person in a single day. They are especially
easy to find immediately after a rain, for then the loose
dirt is washed away from the fragments, rendering them
more easily visible. The writer visited the locality in
1906, and a search of twenty minutes only was necessary
in order to secure a specimen about two inches in length.
At the station of Canon Diablo there were nine large
fragments awaiting shipment, weighing from 75 to 150
Ibs. each, besides several large boxes containing smaller
pieces.
The locality is especially interesting to the geologist,
not only on account of the meteoric masses found there,
but because of the interesting question as to the origin
of the elevation apparently so intimately connected with
them. The mountain or hill contains on its summit a
well defined depression or crater which has a maximum
depth of 600 feet, and a width of 3,500 feet. The walls
of the crater, which are quite precipitous in places, are
formed by the same strata of sandstone and limestone as
those which make up the floor of the plateau. These are
tilted and slope away from the cavity, just as one would ex-
pect, had the strata been uplifted by some great force act-
ing from below, followed by a collapse of the central mass-
There is, however, an entire absence of fused material or
volcanic ejectamenta, and no evidence of metamorphism
of an igneous character having taken place within a
radius of twelve miles. In this respect, the crater is un-
like those usually found in a volcanic region. This fact,
together with the extraordinary occurrence of meteoric
NATIVE ELEMENTS 21
iron, has led to the supposition by many that the depres-
sion was not caused by volcanic action, but by the impact
of an immense meteor nearly one-half mile in diameter,
which on striking the earth buried itself and formed up-
turned edges very much as when a bullet falls into soft
mud. Others look upon the phenomenon as having been
caused by a volcanic explosion which lacked energy suf-
ficient to bring the fused mass to the surface. The ex-
plosion was followed, it is supposed, by a complete ces-
sation of vulcanism. This seems to be the better explan-
ation, since it can easily be seen that such an explosion
might occur on the border of a region of such extreme
volcanic activity as was able to produce the most lofty
mountain in Arizona as well as more than a hundred
small cinder cones. 1 Dr. Chamberlin of Chicago Univer-
sity looks upon the formation as having been produced
by an explosion, due to the vaporization of underground
water, brought about by the near approach of molten
rock.
Further, there seems to be some doubt on the part of
some regarding the meteoric origin of the iron frag-
ments. Dr. Karl Hintze, in his Handbuch der Min-
eralogie, refers to the Canon Diablo irons as possi-
bly of terrestrial origin (" terrestrisch vielleicht " ) .
H. Moissan also makes the statement, " Ce fer
de Canon Diablo a e*te regarde par certains ge*ol-
ogues comme une meteorite, et par d'autres comme
1 Coon Mountain and its Crater, D. M. Barringer : Proc. Ac. Nat. Sc., Dec.,
1905 ; Coon Butte, Arizona, B. C. Tilgham ; Ibid, Coon Mountain Crater, F. N.
Guild : Science, 26, p. 24.
22 THE MINERALOGY OF ARIZONA
un fer terrestre analogue au fer d'Ovifak decouvert au
Greenland par Nordenskiold." l
The composition of the iron, as shown by the follow-
ing analyses made by H. Moisson, of Paris, varies greatly
in different parts of the same fragment.
1234
Per cent. Per cent. Per cent. Per cent.
Iron 91.12 95.06 91.09 92.08
Nickel 3.07 5.07 i. 08 7.05
Small quantities of silica, magnesia and phosphorus
are also reported.
The Weaver Meteorite. This large meteoric fragment
was found in the Weaver mountains, near Wickenberg,
Maricopa Co., in 1898. It is of especial interest on
account of its high percentage of nickel and cobalt and
its uniformity of texture, etching solutions failing to
bring out any very characteristic figures. The locality
in which it was found has yielded but one fragment of
rounded outline, weighing about eighty pounds. Two
analyses of this meteorite have been made in the writer's
laboratory by Mr. W. B. Alexander and Mr. F. Hawley.
The results are shown in the table below.
Alexander Hawley
Iron 79.60 81.81
Nickel 18.80 16.63
Cobalt i. 60 1.18
Carbon, manganese, and phosphorus. . Traces Traces
Specific gravity 7.9818 7.987
The meteorite was furthur investigated spectroscopi-
cally for helium, but with negative results.
i Trait^ de Chimie Mineral, Vol. 2, p. 192.
II. SULPHIDES, ARSENIDES, ETC.
Tetradymite, Bi 2 (Te,S) 3
This is a soft, steel-gray mineral consisting of bismuth,
sulphur and tellurium. It has been found in small quan-
tities in the Montgomery Mine. 1 It also occcurs in
quartz associated with pyrite near Bradshaw City,
Yavapai Co., where it is found slightly altered to a
brownish decomposition product, probably Montanite,
the bismuth tellurate. 2 This mineral frequently contains
gold, and is often associated with that metal in the tel-
luride ores of Colorado and California.
Molybdenite, MoS 2
This is a soft mineral, closely resembling graphite in
its general appearance. It contains sulphur and the
semi-metal molybdenum. The mineral seems to be quite
widely distributed in Arizona, where it is frequently
found as an accessory in many of the copper, lead and
silver deposits. In the Morenci fissure vein, it occurs
in primary association with pyrite, chalcopyrite and zinc
blende. It is also present in the ordinary smelting ore
of the district, as shown by chemical analysis. 3
In the Santa Rita mountains, 30 miles south of
Tucson, it is found in the form of small foliated aggre-
1 Dana : Text Book of Mineralogy, p. 285.
2 Genth : Am. Jour. Sci., 3d series, 40, p. 114.
3 L,indgren : U. S. G. S., PP. No. 43, p. 107.
24 THE; MINERALOGY OF ARIZONA
gates in pure milky quartz, where it alters to molybdite,
or the hydrous ferric molybdate. 1
In the Silver Bell district, northwest of Tucson, it
occurs in large masses, sometimes of three or four pounds
weight, consisting of crystalline aggregates, and asso-
ciated in the same hand specimen, with quartz, galena,
pyrite and chalcopyrite. It has further been observed
associated with secondary sulphides of copper in the
mines at Johnson, near Cochise.
Domeykite, Cu 3 As
This is a rare arsenide of copper usually presenting a
tin-white lustre, easily tarnishing to a dull bronze. It
is very tough and somewhat malleable under the ham-
mer. Good specimens of this mineral have been received
at the University of Arizona from Cochise County, but
no data regarding the associations and mode of occur-
rence have been obtained.
Argentite, Silver Glance, Ag 2 S
This is a dark lead-gray mineral resembling copper
glance but easily distinguished from it by its being more
easily cut with a knife. It has been reported from the
Silver King mine, and is occasionally met with as an ac-
cessory in other metalliferous deposits of the State.
It is further a quite constant constituent in argen-
tiferous galena but is so intimately mixed with it as to
escape observation.
i Guild : Am. Jour. Sci., 23, p. 455.
SULPHIDES, ARSENIDES, ETC. 2$
Hessite, Ag 2 Te
This is a rare telluride of silver with nearly always
some gold. It has been reported from the West Side
mine, Tombstone. 1
Galena, Lead Glance, PbS
This well known mineral is widely distributed in the
State, as is shown by the official reports on the pro-
duction of lead from the different counties. In all about
five millions of pounds of the metal were produced in
1905, the greater portion of which was obtained from
this mineral. The following counties were represented :
Cochise, Graham, Mohave, Pima, Final, Santa Cruz,
Yavapai and Yuma. 2 The frequent occurrence of this
mineral with gold has been mentioned by W. P. Blake. 3
It is frequently found associated with the oxidized
products of lead such asanglesite, cerussite, etc., and also
with wulfenite, vanadinite, decloizite, etc. The localities
and different modes of occurrence are too numerous to
mention.
Chalcocite, Copper Glance, Cu 2 S
This also is a well known mineral usually found in the
zone of secondary sulphide enrichment where percolating
copper solutions have come in contact with lean sulphides.
It is especially abundant in the Clifton-Morenci dis-
trict where it is found in disseminated grains and seams
in altered porphyries. It is not a primary mineral here as
1 Hintze : Mineralogie, p. 453.
2 Mineral Resources, 1905. p. 138.
3 Rep. to Gov. of Ariz., 1899, p. 105.
26 THE) MINERALOGY OF ARIZONA
supposed by some, but has been formed by the replace-
ment processes taken place between grains of pyrite or
chalcopyrite and descending copper solutions. 1
In the Copper Queen mine at Bisbee it is only occasion-
ally found, where it is described as an envelope on pyrite
showing the first stages of a secondary enrichment
process. 2
Stromeyerite, Ag 2 S, Cu 2 S.
This mineral can hardly be distinguished from copper
glance except by chemical analysis. The essential differ-
ence consists in the large percentage of silver. It has
been observed in the Heintzelman mine, 8 and in the Silver
King mine, Final Co.
Sphalerite, ZnS.
This mineral is a sulphide of zinc and varies in color
from yellow and almost white, through orange tints to
black. When pure, it has a characteristic resin-like
luster. The darker varieties owe their color to the
sulphide of iron, which is present as an impurity. These
dark modifications are frequently called by the miners
black jack or mock lead ; the purer samples are referred
to as rosin jack.
Sphalerite has been frequently found as an accessory
ore in many of the mines of the State, associated
with argentiferous galena, pyrite and chalcopyrite. It
has been noted below the zone of secondary enrichment
in the Clifton-Morenci district, disseminated in hard
i Lindgren : U. S. G. S M PP. No. 43-
U. G. S., PP. No. 21, p. 128.
8 Dana : Text Book of Mineralogy, p. 290.
SULPHIDES, ARSENIDES, ETC. 27
limestone and metamorphic rock. 1 It is found in the
silver-lead prospects in the San Xavier district, asso-
ciated with galena and other sulphides. Small quantities
have been reported from the copper deposits of the Hoi-
brook and Gardiner shafts, 2 Bisbee. In the Silver King
it has been observed as occurring in light sea-green
masses, associated with threads of native silver, which
sometimes cement the cleavage masses together. 3 It
further occurs below oxidized gold ores in the Montana
mine of the Oro Blanco district, Santa Cruz Co. The
disastrous effect of passing from free-milling gold or
silver ores into these basic sulphides is well known.
Zinc of commercial importance has been produced by
the Copper King Mines Co., operating in the Tiger dis-
trict of Yavapai County. 4
Alabandite, MnS
This rare sulphide is quite abundant in the lyucky
Cuss mine at Tombstone ; it is usually associated with
manganiferous limestone, in both massive forms and
specimens possessing good cubic cleavage. It is dull
black in color and can easily be recognized from the fact
that it gives a dark green streak or powder.
Cinnabar, HgS
The red sulphide of mercury is found in Yuma Co. , on
the properties of the Colonial Mining Co., 14 miles from
Ehrenberg. The ore is said to average about i}4 per
1 Ijndgren : U. S. G. S., PP. No. 43.
2 Ransome : U. S. G. S., PP. No. 21.
3 W. P. Blake : Rep. to Gov., 1899.
* Min. Res. of the U. S., 1905.
28 THE; MINERALOGY OF ARIZONA
cent, of mercury. The same mineral has also been re-
ported from Yavapai County. 1
Covellite, CuS
This is an indigo blue sulphide of copper, frequently
met with in the Butte mining district, Montana, but very
rare elsewhere. It has never been found in good speci-
mens in Arizona, and, in fact, has been noted only in the
Ryerson and Montezuma mines in the Clifton- Morenci
districts. 2
Bornite, 3Cu 2 S.Fe 2 S 3
This beautiful sulphide of copper and iron can easily
be recognized from its striking iridescent tarnish, for
which reason it is frequently called variegated copper ore,
or peacock ore. The colors vary in the same hand speci-
men from golden yellow and greenish tints to rich brown
and purple. It is nearly always associated with pyrite
and the various sulphides of copper.
Bornite is frequently met with in the zone of sulphide
enrichment in the Bisbee district and in other copper
deposits of the State.
Chalcopyrite, Cu 2 S.Fe 2 S 8
This mineral is known as copper pyrites and can be
distinguished from iron pyrites which it closely resembles
in its inferior hardness and usually by its duller and more
brass-like luster. It occurs in the Copper Queen mine,
especially in the lower levels where frequently large
bodies are encountered, is less abundant in the Clifton-
1 Min. Res. of U. S., 1905, p. 398.
Lindgren : U. S. G. S., PP. No. 43.
SULPHIDES, ARSENIDES, ETC. 2O,
Morenci district, but constitutes the chief ore in the
Jerome, Silver Bell, Twin Buttes, Helvetia and other
properties.
Chalcopyrite is probably the mineral in which the cop-
per in many, if not all, of the mines of the State
originally existed. It was probably mixed with large
proportions of iron pyrites, and might in most cases
more appropriately be called cuperiferous iron pyrites.
The other minerals have been derived from it by what is
known as metasomatic or replacement processes. This
goes on very much as follows : The lean sulphide, chalco-
pyrite or, as suggested above, iron pyrites which contain
a small amount of this mineral, on being exposed to the
action of air and water, becomes oxidized, setting free
among other constituents copper sulphate, which is solu-
ble in water. This solution descends, and coming in
contact with the lean sulphides below, a replacement
takes place by which copper is deposited in the molecule
and iron removed. 1 The deposit is then called an enrich-
ment zone, and such sulphides asbornite, chalcocite, etc.,
result.
Pyrite, FeS 2
This mineral is so well known on account of its wide
distribution that no extended account of its occurrence in
Arizona is necessary. It is found as a microscopic ac-
cessory mineral in many of the igneous rocks, especially
the basic dikes, and as an association in the copper, lead
and other metalliferous deposits, including gold bearing
i See Chalcocite, where a first stage of this process is mentioned.
3O THE MINERALOGY OF ARIZONA
veins. In the latter case it is not unusually present near
the surface, having been oxidized to limonite or hematite,
thus giving the rock a rusty honey-combed appearance.
This part of the vein material is called " free-milling, "
since the pyrite which originally held the gold enclosed
in its firm crystalline structure, has become disintegrated,
setting * ' free ' ' the gold which can then be easily ex-
tracted by well known metallurgical processes.
Schreibersite, (Fe, Ni, Co) 3 P
The mineral is a phosphide of iron with some nickel
and cobalt. It occurs only in meteorites, and has been
reported from the Canon Diablo irons. 1
Cobaltite, CoAsS
Cobalt ores, presumably of economic value, have re-
cently been discovered in the vicinity of Jerome. The
minerals have not been thoroughly investigated yet, but
cobaltite, associated with erythrite, or cobalt bloom, has
been positively identified. 2
Cohenite, Fe 8 C
As a' mineral, this compound has been found only
in meteoric iron. It is a carbide of iron, as the formula
given above indicates, and analyses from material isolated
from the Canon Diablo irons, have been reported by
Derby. 8
1 Derby : Am. Jour. Sci., 1895, 49, 107.
2 See Erythrite.
* Am. Jour. Sci., 1895, 49, 106.
ID. SULPHO-SALTS, SULPHARSENITES, ETC
Bournonite, (Pb, Cu 2 ) 3 S.Sb 2 S 3
This rather rare mineral has been described by Profess-
or W. P. Blake as associated with pyrite, sphalerite and
galena at the Boggs mine, in the Big Bug district. 1 It
is a soft, easily fusible dark steel-gray mineral, possessing
the chemical composition of a sulphantimonate of lead
and copper.
Tetrahedrite, or Gray Copper, Cu 8 Sb 2 S 7
This is a sulphantimonite of copper with varying
amounts of the metal replaced by silver, lead, zinc, etc.
It more often accompanies silver ores than copper. In
Arizona it occurs in the Heintzelman mine and the Silver
King, Pinal Co., where assays have run as high as 3,000
ounces silver to the ton. 2
Pyrargyrite and Proustite, or Ruby Silver Ores
Ag 3 SbS 3 , and Ag 3 AsS 3
These rare minerals are the sulphantimonites and
sulpharsenites of silver. They have occasionally been
met with accompanying other silver ores in many of the
ore deposits of the State. (Dana.) When first taken
from the mine they possess a beautiful pure ruby color.
Unfortunately, however, on exposure to light, they
1 Am. Jour. Sci., 3d series, 39, p. 45.
2 W. P. Blake : Report of Ter. Geologist, 1909.
32 THE MINERALOGY OF ARIZONA
darken and finally become dull black. The beautiful
masses from Mexico, preserved in the British Museum,
have kept their ruby aspect, having been enclosed in
black boxes.
Polybasite, Ag 9 SbS 6
This is another rare sulphantimonite of silver, differ-
ing from ruby silver, in containing a larger percentage
of silver. It has been observed in the Silver King mine.
(Dana.)
IV. CHLORIDES, FLUORIDES, BROMIDES, ETC.
Halite, Common Salt, NaCl
This mineral is found dissolved in the water of all
streams, springs and underground sources, but ordinarily
in such small quantities as to be hardly perceptible except
by chemical analysis. It has been found in beautiful
transparent masses associated with thenardite, mirabilite
andglauberite in the Verde Valley, Yavapai Co., where it
appears in irregular deposits in the more abundant sul-
phates mentioned above. The deposit has resulted from
the evaporation of an inland sea or lake. 1 This mineral
is further found in salt springs in the upper Salt River
Valley.
Cerargyrite, or Horn Silver, AgCl
Horn silver, the miner's name for the chloride and
bromo-chloride of silver, can be easily recognized from
its waxy appearance, and from the fact that it can be cut
with a knife into thin shavings which do not fall apart.
It has been frequently observed in the zone of oxidation
in many of the silver deposits of the State. It has
been reported in the following districts : Tyndall, Santa
Cruz Co., Cerro Colorado, Black Warrior and others.
Embolite, Ag(Cl, Br)
This mineral is very similar to the one mentioned above,
usually occurring in greenish waxy grains, disseminated
i W. P. Blake : Am. Jour. Sci., 3d series, 39, p. 44,
34 THE MINERALOGY OF ARIZONA
through the vein material. It is especially abundant in
the Pearce mining district.
lodobromite, Ag(Br, I)
This mineral resembles embolite in chemical composi-
tion, but has its chlorine replaced by iodine. The mineral
is extremely rare, but has been reported from the Hech-
man mine, near Globe, by Professor W. P. Blake. 1 It
appears as a bright yellow to pale greenish thin incrusta-
tion in veins of quartz and calcite.
lodyrite, Agl
This is another very rare mineral of silver appearing
in almost identical forms with the proceeding. It has
been found in the Cerro Colorado mines.
Fluorite, or Fluospar, CaFl 2
Fluospar is a well known mineral, occurring in a great
variety of colors, purple, green, pink and white being the
most common. It is easily recognized by its hardness and
octahedral cleavage, breaking up into small pieces with tri-
angular surfaces. It is a quite common gangue mineral
in metalliferous deposits, especially found associated with
lead ores. In the mines of the Silver Bell district, it oc-
curs in green cubes with barite, galena and chalcopyrite.
In the Castle Dome district north of Yuma, it is found
associated with galena, vanadinite, and minerals of silver.
In the Dragoon mountains it is found in small quantities
in very acid pegmatites associated with huebnerite. It
has also been observed in the coarse unmineralized gran-
i Am. Jour. Sci., 4th series, 19, p. 230.
CHLORIDES, FLUORIDES, BROMIDES, ETC. 35
ites at the Laguna dam on the Colorado river. Small
quantities of this mineral have been produced commer-
cially in Arizona and have sold at prices as high as $i 1.50
per ton. 1
Atacamite, Cu 2 Cl(OH) 3
This mineral which is a rare hydrous chloride of cop-
per has been found only in very small quantities in the
United Verde mine, at Jerome, and in the Heintzelmann
mine. A similar mineral called Footeite has been de-
scribed from the Copper Queen mines at Bisbee. (Koenig) .
i Min. Res., 1903.
V. OXIDES
Quartz, Si0 2
Quartz is the most common of minerals, occurring as
sand, gravel, sandstone, quartzite, flint, chalcedony,
agate, as constituent of granite, quartzporphyries, etc.
Sandstone. A beautiful red sandstone has been quite
extensively worked near Flagstaff and widely used as an
ornamental building stone. It is rather soft and does not
stand well the action of frost and moisture.
Chalcedony. This variety of quartz is wax-like in
appearance, translucent and of uniform color. The
various colors are given different names ; for example,
red samples are termed carnelian, green varieties prase
and chrysoprase. The most common color, however, is
a peculiar tendon-like tint, and as such the mineral is of
very common occurrence in Arizona. It is a secondary
mineral, resulting from the disintegration of rocks,
usually volcanic, by which an excess of free silica is
produced. The mineral is then deposited in the cracks
and other cavities of the rock, and being much harder
than the rock in which it occurs, endures long after the
main portion of the mass has suffered complete disinte-
gration. Thus it is frequently found as pebbles and
rounded masses in the streams and on the mesas.
Agate. This is simply a variegated chalcedony, the
irregularities sometimes taking the form of bands which,
when parallel and of alternate light and dark colors, con-
OXIDES 37
stitute the onyx and sardonyx. When the variegations
are in the form of moss-like or dendritic growths, the
specimen is known as the moss-agate. The mineral is
formed in exactly the same manner as chalcedony, the
variegated tints being due to small amounts of various
oxides, which serve merely as coloring matter. Some of
the most beautiful agates are formed in lavas, which
when they were erupted, contained such quantities of
gas and water vapor, that large rounded cavities were
formed by their expansion when the lava cooled. As
described above, these cavities become filled with silicious
matter, which from year to year varied slightly in com-
position, thus giving rise to a concentric banded struc-
ture. Sometimes the cavity is not completely filled, in
which case the mineral is like a hollow shell, frequently
lined with the most beautiful crystals. These are called
geodes, and are occasionally found in the streams of
Arizona, where they have been washed out of the rock
which contained them. They are also found in place
embedded in what is known as the Aubrey limestone,
which is abundant in the northern part of the State.
Agates in Arizona have been described from the lavas of
the Tucson range of mountains, 1 and as blue gray
amygdules coated with opal from other portions of the
State. 2
Diatomaceous Earth. This is a variety of silica, per-
haps more accurately described under opal, which forms
the shell of microscopic organisms. It is deposited in
1 Guild : Am. Jour. Sc., 4th series, 20, p. 313, Plate IX.
2 Kunz : Gems, p. 130.
38 THE MINERALOGY OF ARIZONA
quiet water, either lake or ocean. A snow white deposit
of this material, occurring in the San Pedro Valley, and
associated with fine volcanic ash, has been described by
Professor W. P. Blake. 1 Deposits of the same material
are also described in the Bradshaw folio of the United
States Geological Survey.
Petrified Wood. This form of silica or quartz is very
abundant in Arizona, whose specimens are justly prized
by museums and private collectors in all parts of the
world. The material is especially abundant in the re-
gion of the Grand Canon and extending southward along
the Colorado river to Yuma. The petrifaction sometimes
takes the form of impure silicious matter, in which the
exact form and structure of the wood is preserved, but
not in very pleasing tints. At other times the silicifica-
tion is in the form of chalcedony, jasper, agate, etc., giv-
ing rise to very striking and beautiful specimens. It is
remarkable that all these brilliant tints are sometimes
mingled in the same piece. A section of a large log
showing these variegated tints, weighing over 15 tons,
has been polished and deposited in the Museum of Nat-
ural History in Paris. The most highly prized specimens
are found in the vicinity of Holbrook and Adamana,
where many square miles are literally covered with
petrified logs, branches and small broken fragments of
bright colors. These have been highly prized by the
Indians on account of their hardness and color, and may
be found with other Indian relics in various parts of the
southwest.
i Am. In. Min. Eng., 33, 1903, 38.
Fig. 2.
A microscopic section of petrified wood, showing the original cell structure.
OXIDES 39
Geologically the petrified wood of Arizona is supposed
to occur in the middle Triassic beds called by Powell the
Shinarup group and possessing a thickness of about 1600
feet. The petrified wood is found throughout the entire
thickness.
Theory of Petrifaction. Petrifaction takes place
through well known processes of chemistry, by which
the molecules of a substance are removed one by one and
the molecules of another material deposited in their places.
It may be likened to a house originally built of brick in
which each brick is carefully removed one by one and
a block of marble put in its place until the entire house
is changed to marble, yet the shape of the original struc-
ture during the whole process in maintained. Thus when
a forest becomes buried and subjected to the action of
silicious waters, usually hot, a particle of wood decays and
a molecule of silica is moulded into its place, the process
being carried on with such delicacy that the cells, annu-
lar rings, bark, knots and other characteristic features
are accurately preserved in stone. How completely and
delicately this replacement process has progressed may
be seen by the accompanying cut which is a reproduction
of a photomicrograph of a thin section taken across the
grain. Replacement processes of this nature are well
known in mineralogy and in fact are the chief agencies
at work in producing ore deposits of sufficient enrich-
ment to be of economic value. (See Chalcocite, p. 25.)
Jasper. Jasper occurs in a variety of colors and differs
from chalcedony in being more opaque and less pure.
4O THE MINERALOGY OF ARIZONA
The common color is red, and in this shade it is frequently
found in pebbles in the streams and in angular fragments
on the mesas and in the mountains of the State. In
the Petrified Forest, as described above, it is abundant
as jasperized wood.
Chrysophase. Blue and bluish green copper-stained
chalcedony has been found in abundance near Globe.
' ' The mineral occurs in small stringers in the Keystone
copper mine in that district. The copper ore of this
mine is said to be principally chrysocolla or silicate ore.
The chalcedony varies in color from bright to pale blue,
bluish green, and nearly apple-green, and is more or less
translucent. In some places the color occurs in curved
layers and varies in intensity, thus bringing out the
mammillary structure of chalcedony in peculiar wavy
markings. In other places the color approaches that of
chrysoprase, or resembles that seen in certain artificially
colored chalcedony. Mr. Wightman reports a sale of
probably 200 pounds of selected material during 1907 by
the miners at Globe. After cutting, this blue chryso-
prase brings locally from $3.00 to $10.00 a piece for the
best grades. ' ' l
Flint and Chert. These are still less pure varieties of
silica. They are found as pebbles in the streams, as ir-
regular nodules in limestone, especially in the Aubrey
limestone in the Grand Canon region, and in various
other forms.
Amethyst, or amethystine quartz is clear quartz col-
i Min. Res., U. S. G. S., 1907, p. 802.
OXIDES 41
ored purple by traces of manganese. It is sometimes
met with in the quartz veins of the State, but in
such quality as to make it desirable only as museum
specimens. Mr. Kunz has described it as occurring in
cavities in the petrified wood of Arizona. 1
In the McConnico district it is found in precambrian
rocks, sometimes in samples of great beauty. One crys-
tal is reported to have been sold to Tiffany, of New
York City, for $59. oo. 2
Opal, Si0 2 , H 2
Common opal is similar to chalcedony in composition
and appearance, but is uncrystallized and contains a
varying amount of water. The precious varieties are
not found in Arizona. Semi-opal and the clear variety,
hyalite, are occasionally found associated with other
modifications of silica. Kunz has mentioned hyalite in
Yavapai County.
Cuprite, Cu 2
The red oxide of copper or cuprite, occurs in massive
varieties, resembling hematite, in crystalline modifica-
tions in the form of cubes, octahedrons and dodecahe-
drons, and in capillary incrustations of vivid red. This
latter variety is sometimes known as plush copper ore
and chalcotrichite, and the transparent variety as ruby
copper. Ruby copper forms beautiful specimens when
first taken from the mine but they soon become dulled
1 Gems, p. 116.
2 U. S. G. S., Min. Res., 1908.
42 THE MINERALOGY OF ARIZONA
on exposure to light. Plush copper which is more brill-
iant red is hardly effected by sunlight. All of the varie-
ties mentioned above are frequently met with in Arizona
and are especially abundant in the Copper Queen mines at
Bisbee and in the Clifton-Morenci district. They are as-
sociated with native copper, hematite, limonite, chryso-
colla and the other secondary ores of copper. Very
pleasing museum specimens are obtained from the Globe
mines which consist of massive dark brown cuprite in
which are little veinlets and irregular spots of delicate
blue chrysocolla.
Tenorite, CuO
This is a somewhat rare mineral and is known as black
oxide of copper. It is found in a pulverulent condition
mingled with manganese dioxide and associated with
other oxidized material in the Copper Queen mines. It
is thought to be still forming in the caverns there as the
mineral is frequently found covering the floor of cavities
where it has dropped from above. 1
Ice, H 2
Except on high mountains and in the northern part of
the State this mineral in the solid or crystallized con-
dition is rare in Arizona. On the northern slopes of the
San Francisco mountains it is sometimes found even in
summer months in the well-known form of snow. In the
southern portion, the high mountain ranges are frequent-
ly covered with it during the winter, and in the valleys
i Ransome : U. S. G. S., PP. No. 21, p. 128,
OXIDES 43
it is well known as frost, and as thin coverings on water
occasionally seen in the early morning.
Ice Caves. In the vicinity of Flagstaff there are
numerous small caves found in both basaltic and
limestone rocks. A few of these have been known
to contain ice throughout the year. It is the cus-
tom of picnic parties to visit these localities, well
supplied with cream and other dainties, which are
then well frozen by the ice thus prepared and stored
by nature. The writer visited one of these caves in
the summer of 1906. It was located on the black lava
flow at the base of Sunset Peak where the streams of lava
had evidently cooled, forming a solid crust of basalt
which, due to further movement of the mass beneath, had
broken up the lava crust into a heterogeneous mass of
angular blocks and fantastic shapes of such complexity as
to make description impossible. It most resembles an
ice-dam formed during the spring on many of the northern
rivers, except that the material is black and covered by
numerous small craters caused by the escape of steam
from beneath. In this irregular mass are numerous small
caves formed by the piling up of blocks of basalt as well
as by the recession of liquid lava leaving cavities with thin
dome-like roofs. In these cavities the ice has collected
during the spring and winter months and owing to the
nonconducting character of the rock, does not completely
thaw during the warm summer. It had been preserved
by nature very much as ice is stored in northern climates,
by packing in some nonconducting substance. In these
44 THE MINERALOGY OF ARIZONA
caves the ice appears as coverings on the floors and as
stalactites (icicles) hanging from the ceilings.
Hematite, Fe 2 3
This well known mineral, the anhydrous oxide of iron,
is found everywhere and in a great variety of forms. It
is abundant in all mines where oxidation of sulphides has
taken place and is the cause of the red color of many ores,
minerals and soils. When well crystallized it is called
specular iron and frequently forms beautiful cabinet
specimens especially when showing an iridescent tarnish.
It is frequently found in Arizona as a contact mineral
associated with epidote and similar minerals. It is fur-
ther found in large beds where it can be utilized as a basic
flux in smelting.
Magnetite, Fe 3 4
This is the black magnetic oxide of iron, and is
found as a microscopic accessory in nearly all rocks.
From this source it finds its way into black sands and
similar deposits. It is further found, like hematite,
associated with contact minerals and in a great variety
of ways. In the Tucson mountains it is found as rounded
transported blocks, frequently pitted in a manner to re-
semble meteorites.
Pyrolusite, Mn0 2
The Black oxide of manganese, or pyrolusite, has been
noted in the Clifton-Morenci district mixed with limonite. 1
Samples from other localities have been received at the
i I^indgren : U. S. G. S., PP. No. 43.
OXIDES 45
University of Arizona, but data regarding their mode of
occurrence are lacking.
Limonite, Fe 2 3 3H 2
Limonite, or the hydrous oxide of iron is very abun-
dant ; it is associated with oxidized ores in the Copper
Queen mine where, together with hematite, it is the cause
of the reddish color of the ores. It is frequently found
in mammillary and kidney shapes. In general its mode
of occurrence is similar to that of hematite, from which
it can hardly be distinguished except by chemical means.
VI. OXYGEN SALTS
(i). CARBONATES
Calcite, CaC0 3
The various modifications of calcite are found in nearly
every mountain range of the State and have frequently
been described in geological literature.
Limestone. This well known rock or mineral varies
greatly in composition and appearance in different parts of
the State. In many places especially in the vicinity of
the Grand Canon, it is very impure containing often large
quantities of both silica and magnesia. The silica is
sometimes in the form of nodules and geodes and some-
times as fine sand or silt intimately mixed with the car-
bonate. The magnesium is always in the form of mag-
nesium carbonate. The following analyses made by the
writer on samples obtained in the vicinity of Flagstaff
will give an idea of its composition. In geological litera-
ture the formation is known as the Aubrey Limestone.
No i No 2 No 3
Per cent. Per cent. Per cent.
Silica 34.10 17.00 72.21
Iron and alumina 1.60 i.oo 2.91
Calcium carbonate 33. 8 r 48.20 18.60
Magnesium carbonate... 26.43 34-4 5-62
Total 95-94 100.60 99-34
It will be seen from the analyses that No. 3 at least is
a calcareous sandstone rather than limestone, and in fact,
OXYGEN SAWS 47
all gradation may be found in this district between pure
sandstone on the one side and pure limestone on the other.
The formation known as the Red Walled Limestone in
the Grand Canon is much purer in composition. A large
area of this has been exposed in the vicinity of Flagstaff
through the intrusive action of some of the crystalline
lavas of the San Francisco mountain district. It is found
in direct contact with andesite on the north flank of
Elden Peak, about nine miles from town. It has been
used in the manufacture of lime, and is said to give ex-
cellent results. Its chemical composition is represented
in the table below.
Silica * . . . 0.27
Iron and alumina 1.24
Calcium carbonate 95.84
Magnesium carbonate 0.90
Alkalies 0.48
Total 98.73
An interesting case of contact metamorphism was ob-
served at the immediate contact of this pure limestone or
marble with the crystalline andesite. Here the lime-
stone has become very fine grained and taken on the ap-
pearance of lithographic stone. The alteration is plainly
due to the influence of the igneous mass by which the
marble or limestone has become both silicified and dolo-
mitized. The chemical reactions which have taken place
in this transformation may be inferred from the following
table, which contains the analysis of a sample taken about
five feet from the contact.
48 THE MINERALOGY OF ARIZONA
Per cent.
Silica 19.41
Iron oxide 2.02
Alumina 8.82
Calcium carbonate 46.30
Magnesium carbonate 25.43
Total 101.98
Marble. Marble or crystallized limestone has fre-
quently been used in Arizona for building purposes. The
local demand, however, is very slight, and freight rates
are such that it cannot be transported great distances.
Samples sent to the University of Arizona, from various
localities, seem to show that it is abundant and frequently
of very pleasing color.
Onyx Marble. This beautiful stone, more frequently
known as Mexican Onyx, has been found in Arizona in
tints and variegated effects equal in every respect to the
Mexican product. Mineralogically it may be considered
as stratified and variegated calcite or aragonite, the bands
and irregular coloring effects being caused by the arrange-
ment of such foreign pigments as iron oxide in various
stages of oxidation and hydration. The most important
locality in Arizona is near Mayers about 26 miles from
Prescott. The deposit is approximately twenty acres in
extent and the workable material is described as occur-
ring in bowlders containing from two to thirty cubic feet. 1
Other localities are Greaterville, Kirkland Valley, and
Oak Creek.
Caliche. This is a word of Spanish origin loosely em-
i W. P. Blake : Rep. to Gov., 1899.
OXYGEN SAI/TS 49
ployed by the Mexicans and others in the south-western
United States and Mexico to designate almost any non-
crystalline crust. It was perhaps first used by the Chil-
lians who applied it to the soluble saline crusts of their
country which consisted mostly of crude nitre and other
soluble constituents. In some parts of California the term
is still used in a similar manner, perhaps with particular
reference to the top coatings. 1 In Arizona the term is
usually applied to a calcareous deposit of varying hard-
ness found to exist in many soils and gravels. It results
from the evaporation of meteoric water in situ, and of
water brought down from the mountains and distributed
throughout the valley in the form of underground streams
and reservoirs. The calcareous matter owes its ultimate
origin to the decomposition, through the influence of
dilute solutions of carbonic acid, of complex calcium sili-
cates of the soil and rocks. The following reaction is
given as an illustration of this decomposition :
Lime Feldspar + Alkali Feldspar -f- Carbonic Acid =
CaAl 2 Si 2 8 KAlSi 3 8 H 2 CO 3
Calcite (caliche) -f- Muscovite (sericite) -f Quartz.
CaC0 3 H 2 KAl 3 Si 3 12 2SiO 2
The reaction f urthur explains the presence of alkali in
the soil, since the continued action of CO 2 , or H 2 CO 3 ,
would convert the muscovite into K 2 CO 3 and kaolin.
The two constituents kaolin and alkali may also be
formed direct from the feldspar as shown by the follow-
ing reaction :
1 Bailey : The Saline Deposits of Cal., Bui. No. 24, Cal. State Min. Bureau.
50 TH MINERALOGY OF ARIZONA
Ortlioclase + Water -f- Carbon Dioxide
6KAlSi 3 8 6H 2
Kaolin -f Alkali -f Silica.
3H 4 A.l 2 Si s 9 3K 2 C0 3 i2SiO 2 .
The alkali is not found to any extent in the caliche, since
its great solubility compels it to remain mostly in the un-
derground waters. The kaolin, or clay, and the silica rep-
resented in the above reaction are always present in large
quantities. The muscovite then is only an intermediate
product, easily seen in decomposing rocks by means of the
microscope, but later altering into kaolin or clay. As may
easily be inferred, caliche is a deposit occurring only in
arid countries where evaporation is rapid and circulation
of at least surface waters slow and incomplete. It is
therefore abundant in Arizona and in arid portions of
California and Mexico. In appearance it is a light buff
shading to white, and seems to be made up of the ordi-
nary constituents of the soil such as silt, sand, gravel and
small pebbles firmly cemented together by calcium car-
bonate. Occasionally it is faintly stratified, the layers
being due to successive depositions from solution rather
than sedimentation. As a deposit in ordinary soils it is
always formed beneath the surface ; where erosion has
not taken place, there are a few inches to several feet of
earth on top. Its occurrence, however, is not limited to
within a few feet of the surface ; it is sometimes found in
layers of varying thickness alternating with loose sand or
gravel to a depth of seventy-five feet or more. The deeper
layers differ somewhat in character from those near the sur-
face. These usually consist of coarser particles of gravel
OXYGEN SALTS 51
and pebbles and of even small bowlders cemented by a
more crystalline calcium carbonate into a mass of such hard-
ness that a well can be sunk into it only with the greatest
difficulty. Indeed, it is sometimes necessary to resort to
the use of blasting powder. The spaces between the
pebbles are lined with drusy scalenohedral crystals of
calcite and even well formed geodic cavities are some-
times observed. Evidently the deposition here took place
under more uniform and deeper seated conditions than
those which gave rise to the finer grained amorphous
surface deposits. The deposit is not merely local in
character, but many hundreds of square miles are ren-
dered useless for agricultural purposes by its presence.
As previously stated, it would seem that the two modi-
fications of this deposit described above owe their origin
to two closely related phenomena : (i), the layers near
the surface, to the evaporation of meteoric waters in situ ;
(2), the deep-seated layers, to evaporation of waters
brought up by capillary attraction to-some definite position
which depends upon local conditions, such as fineness of
material, pressure, etc. Of course it can easily be seen that
where underground waters exist near the surface the
top layers might be formed in the way last mentioned.
Then evaporation at depth would not take place. Again,
in places where there is no underground water at reason-
able depths, only the first mentioned cause would be oper-
ative. In either case the deposition takes place beneath
the surface and never precisely upon it. The reason for
this is to be found in the climatic conditions of the South-
west. Immediately after a rain the sun quickly reap-
52 THE MINERALOGY OF ARIZONA
pears, rapidly drying the surface of the ground and thus
preventing furthur action of capillary attraction. Iftie
earth becoming like a dry sponge is unable to soak up
moisture from below. The depth to which this superficial
drying takes place depends upon local conditions such as
texture of the soil, vegetation and other features. The
remaining meteoric water is now brought up by capillary
attraction to the point where evaporation begins and
capillary attraction ends. This action continues until all
of the water is evaporated, is repeated after the next
rain, thus giving rise to faint stratifications, until finally
a deposit of considerable thickness is formed.
The deposition taking place through the evaporation of
underground waters may progress at any depth, though
with less rapidity as the depth increases. The exact
position in which the deposit is forming during any
series of years depends, first, upon the height of the
underground water, and second, upon the distance
through which capillary attraction is able to act under
the existing conditions of porosity, pressure, or other de-
termining agents. Thus, if the underground water at a
certain time is found at a depth of say eighty-five feet,
the calcareous deposit may actually form at that time at
a depth of seventy-five feet or more. Cavities are
actually found at this depth incompletely filled with mi-
nute crystals, a fact which suggests that the deposition is
still going on.
The explanation of the alternate layers of calcareous
material is to be sought in the possibility of the under-
ground waters having occupied higher levels in former
OXYGEN SALTS 53
periods of time. The Tucson Valley, for example, is
filled with debris contributed by the high surrounding
mountains. All of this material was at one time on the
slopes and mountain tops of these ranges. Their alti-
tude, then, must have been a few thousand feet higher
than the present time. As is well known this would
have had the effect of greatly increasing the annual pre-
cipitation which in due course would have greatly aug-
mented the quantity of underground water. Regarding
the outlet of the underground water there is at present
but little known, but it is very probable that erosion and
the solvent action of water has had the effect of decreas-
ing its elevation. Thus it seems quite evident from well
established facts of geology that the underground water
of this valley, occupied in former periods of time con-
siderable higher levels. Evaporations at points slightly
above these surfaces, as described above, would ac-
count for the repetition of the caliche beds.
Caliche, as the term is used in Arizona, was first fully
described in scientific literature by Professor W. P.
Blake, 1 who explained its origin as entirely through
evaporation of underground waters brought up from be-
low by capillary attraction. Dissenting from this view,
Professor R. H. Forbes holds that all of these deposits,
even the deep-seated ones are formed by the evaporation
of rain water which has percolated to a depth of three or
four feet, decomposing the constituents of the soil
through the action of carbon dioxide. The calcareous
i The Caliche of Southern Arizona: Trans. Am. In. Min. Eng., 31, 1901,
p. 220.
54 THE MINERALOGY OF ARIZONA
material thus formed is left behind in the soil on evapor-
ation of the water, a process which is repeated until a
limy hardpan is formed. "The different layers formed
at different depths below the surface mark the various
levels which for geological reasons remained constant for
a long enough period of time to permit the formation of
a layer of caliche just below the surface of that time." 1
Professor C. F. Tolman would confine the term caliche
to the amorphous surface crusts and not the crystalline
cements of the desert gravels. "This cement," he states,
* ' is primarily due to the fact that these basins are practi-
cally undrained. The deeper cement, moreover, may be
largely recrystallized crusts, and without direct relation
to any change in climate or water level." 2 Professor
Tolman also calls attention to the probability of the
Paleozoic limestones being an original source of much of
the calcareous material. 3
Siderite, FeC0 3
This mineral, sometimes known as spathic iron, is fre-
quently developed in Arizona as an alteration product
near limestone especially where sulphides of iron are ox-
idizing. In the Tucson mountains it has been observed
as a decomposition product of the ferromagnesian constit-
uents of basic lavas, in which it is deposited in amygda-
loidal cavities and cracks together with chalcedony, cal-
cite and agate.
1 Quoted in Underground Waters of Salt River Valley, U. S. G. S., W. S. P.,
No. 136, p. no.
2 Manuscript.
* Pub. 113, Carnegie Inst. of Wash., 73.
OXYGEN SALTS 55
Rhodochrosite, MnC0 3
So far as the writer knows, this mineral in a pure con-
dition has not been reported from Arizona. A manganif-
erous limestone, however, is found in the Tombstone
district and on decomposition yields manganese oxide
containing silver. 1
Cerussite, PbC0 3
The carbonate of lead, a heavy and when pure a white
or transparent mineral, is frequently met with in the lead
and silver mines of the State as an alteration product of
galena. The galena first oxidizes to the sulphate or angle-
site, and then coming in contact with solutions containing
carbonates a substitution takes place by which the sul-
phate radical is removed and the carbonate radical in-
stalled. A crystallographic study has been made by
Pirsson on samples from the Red Cloud mine. 2 In the
Bisbee district it is found in Hendricks Gulch associated
with limestone. Here it occurs as an impure friable mass
which in mining breaks up into fine sand. Hence this
variety is sometimes known as cerussite sand.
Azurite, 2CuC0 3 .Cu(OH) 2 ,and Malachite, CuC0 3 .Cu(OH) 2
The blue and green carbonate are abundant in Arizona
and have been so frequently mentioned in the description
of mining districts that little space will be devoted to them
here. The two minerals are nearly always associated
with each other even in the same hand specimen, some-
times so intricately mingled in delicate wavy forms as to
yield very striking and beautiful effects when polished.
1 W. P. Blake : Rep. to Gov., 1899.
2 Am. Jour. Sc., 42, p. 405.
56 THE MINERALOGY OF ARIZONA
The crystalline varieties of azurite sometimes develops in
aggregates of rounded bunches, arranged in such a man-
ner as closely to resemble clusters of grapes. The green
carbonate more often appears as silky radiating tufts or
incrustations on botryoidal surfaces, giving the appear-
ance of green plush. These beautiful forms are found
as the lining of caves or small cavities. Here also are
frequently developed stalactites containing both minerals
in concentric layers. Cross sections of these when pol-
ished show concentric wavy rings of blue and green car-
bonates. Dr. G. F. Kunz has applied the name azur-
malachite to such samples when employed as a gem.
These two minerals are always secondary and are never
found at great depths. They result from the oxidation
of the various sulphides of copper by which action the
soluble sulphates are formed, which on coming in contact
with limestone or carbonated waters, react to form the
carbonates. These are then deposited from solution in
the delicate forms described above.
Aurichalcite, 2(Zn, Cu)C0 3 .3(Zn, Cu)(OH) 2
This rare mineral occurs in pale green and bluish
flakes. It has been reported from the Copper Queen
mine at Bisbee and from theCatalina mountains. (Dana).
(2). SILICATES
The Feldspars
Orthoclase, KAlSi 3 8 . This is a rock-forming mineral,
and as a constituent of granite and the corresponding
OXYGEN SALTS 57
acid eruptives, such as rhyolites, felsites, and quartz
porphyries, is found almost everywhere in the State.
In this mode of occurrence it develops in crystals varying
from microscopic size to crystals an inch in length. In
pegmatites, or the light colored veins which are nearly
always found crossing granites and similar rocks, it is
found associated with quartz and sometimes developed in
large masses of pure material. In the pegmatites of
southern California masses of this kind are frequently
found weighing more than 75 pounds and possessing
uniform cleavage and structure. Good crystals are fre-
quently found ten inches in length. In Arizona there
are no unusual deposits of this mineral. A few good
crystals have been found in the pegmatites of the Catalina
mountains, near Tucson, and good white masses may be
observed in many other localities. The Rincon mountains
have yielded rather fine samples of typical pegmatite.
Microcline. This mineral, which has the same chemi-
cal composition as orthoclase, with slightly different
crystalline structure, has been observed as a microscopic
constituent in the tourmaline aplites found in the vicinity
of Oracle, in the Catalina mountains.
Plagioclases The plagioclase feldspars differ from
orthoclase in composition and crystallization. Chemically
they are isomorphous mixtures of albite, NaAlSi 3 O 8 , and
anorthite, CaAl 2 Si 2 O 8 , different proportions of these two
molecules giving rise to the rather arbitrary varieties,
oligoclase, andesine, loboradorite and bytownite. They
are all rock-forming minerals and are found in diorites,
58 TH MINERALOGY OF ARIZONA
gabbros, and their eruptive equivalents, andesites and
basalts. Andesites are probably the most common erup-
tive in the Territory, and as constituents of these the
plagioclases or triclinic feldspars are very abundant.
Pyroxene
Pyroxene, the common variety of which is augite, is a
complex silicate of calcium, magnesium, iron, etc. It is
a rock-forming mineral, and is abundant in Arizona as a
constituent of andesites, basalts and other rocks.
Amphibole
This mineral is similar to pyroxene in its chemical
composition and variations. L,ike pyroxene, it is very
abundant everywhere as a rock-forming constituent of
granites, andesites, dike rocks and metamorphic schists.
It is a constituent of the more acid and intermediate rocks,
while pyroxene usually indicates a more basic magma.
Actinolite and tremolite are the light colored varieties,
and are frequently found as constituents of the crystal-
line schists. A manganiferous variety, exact locality un-
known, has been analyzed by Mr. Fred. Hawley, a
student at the University of Arizona, with the following
results :
Per cent.
Silica 49-30
Ferrous oxide 15.14
Alumina 3.10
Manganese oxide 6.39
Calcium oxide 23.61
Magnesia o. 14
Undetermined 2.32
Total loo.oo
OXYGEN SAI/TS 59
The mineral is dark brown with columnar divergent
structure. The above analysis would place the mineral
as near dannemorite.
Garnet
Garnet is a complex silicate of calcium and aluminium
in which calcium is frequently replaced by more or less
iron and magnesium, and the aluminium by chromium
and iron. It varies in color from white to black, red,
yellow, green and brown shades being the most common.
Garnetiferous Sand. Garnet is a frequent accessory in
schistose and granitic rocks. These are yielded up by the
rock on disintegration and owing to their ability to resist
erosion and corrosion collect in the eddies of the stream
together with black sand or magnetite. Samples illus-
trating this mode of occurrence have been collected from
the streams of the Catalina mountains which on analysis
are found to correspond to the manganiferous variety or
spessartite.
Precious Garnet. In the exteme northern part of the
State the Moki Indians and others bring into the
towns large quantities of loose garnets many of which are
cut and show a beautiful dark ruby tint. They are
known among gem dealers as the Arizona rubies and are
without doubt the finest garnets in the United States.
They are picked up in gravel deposits and around
ant-hills where these industrious workers have brought
them from the surrounding country. The associated
minerals are peridot, pyroxene, magnetite and similar
minerals. The gem has never been found in place but
60 THE) MINERALOGY OF ARIZONA
owing to its associations, one is authorized in assuming
that it was developed in some of the ultra-basic rocks such
as the peridotites. They are always found in well round-
ed and polished pebbles varying from a few millimeters to
two centimeters in diameter. The latter, however, are
never of gem quality. The average size for cutting is
about one carat ; two carat stones are abundant but the
three carat size is very scarce. The smooth polished sur-
faces of these fragments seems to be due to wind erosion
rather than stream. (See Mineral Resources, 1908.) The
index of refraction of these gems as determined with
sodium light on a Fuess instrument is 1.7500. This
corresponds to the variety pyrope.
Yellow garnet, or variety containing larger quantities
of lime, has frequently been received at the University of
Arizona for identification, and a fine large crystal from
Gila Canon has been described by Mr. Kunz. 1 The min-
eralogical name for this variety is Grossularite.
Massive Garnet. This variety of garnet is very com-
mon in many of the mining districts of the State hav-
ing been developed by contact action between limestone
and igneous intrusion. This modification varies in color
from nearly black to light yellow according to the acidity
of the magma. Near the contact with basic eruptives
the dark colored varieties are formed. It is found in the
Clifton-Morenci district in altered limestone in the form
of andradite, or common iron garnet, yellow to dark
brown in color and of a resinous luster. It is further
found in the same locality intergrown with magnetite,
1 Gems, p. 79.
OXYGEN SAVTS 6l
pyrite, zinc blende and chalcopyrite. 1 It is is also abun-
dantly developed in the Silver Bell, the San Xavier,
Washington Camp and other contact districts.
Chrysolite, (Mg, Fe) 2 SiO,
This is usually a yellowish green mineral consisting of
an isomorphous mixture of the two constituents, iron and
magnesium silicate. It is usually a rock-forming mineral,
and as such is more frequently known as olivine. It is a
normal constituent of basalts and most gabbros, and in
these varieties of rock is of very common occurrence in
Arizona. The crystals are usually so small as to escape
ordinary observation. Yet in some of the basalts of the
San Francisco mountains crystals are found more than
one-half inch in length.
Peridot. Crystals of sufficient purity and transparency
to be useful as a gem are known as peridot. It is found
in beautiful tints near Talkai, and is frequently collected,
together with the red garnets with which they are some-
times found, by the Indians and prospectors. A crystal
from this locality, exhibited at the World's Fair, at Port-
land, in 1905, after being cut, was a beautiful gem of 25%
carats. It was pale yellowish green and took a brilliant
polish. The gem variety of chrysolite is most often
found in the streams as worn pebbles, but is occasionally
found lining cavities in basaltic lavas of sufficient clear-
ness to be used as a gem. Like garnets, they are found
around ant-hills. One hill investigated by members of
the United States Geological Survey was found to be
made up of 75 per cent, of peridot grains, the remainder
ITJ. s. G. s., PP. NO. 43.
62 THE MINERALOGY OF ARIZONA
being garnet, quartz, diopside, etc. They are brought
to the hills from the surface over an area of many square
feet surrounding the ant houses.
Wollastonite, CaSiO,
This is a contact mineral sometimes developed where
igneous rocks of intrusion come in contact with lime-
stone. When pure it is a white mineral of pearly luster
and breaking into splintery forms. Contact deposits are
of common occurrence in Arizona, but this mineral has
not been described from many localities. It has been
mentioned among the contact minerals in the Clifton-
Morenci district. 1
Willemite, Zn 2 SiO,
This anhydrous silicate of zinc is usually a light yellow
mineral somewhat resembling yellow garnet. It has
been observed in Arizona only in very small quantities
in the Clifton-Morenci district, on the north side of
Modoc mountain. It was first discovered here by Mr.
Boutwell, and identified by Messrs. Pirsson and Penfield,
of Yale. It is described as occurring in stout hexagonal
crystals with the usual characteristics of the mineral. 2
Dioptase, H 2 CuSi0 4
This rare, gem -like silicate of copper is found in the
Clifton-Morenci district, as noted by Hill. 3 The crystals
occur in beautiful emerald green incrustations lining
cavities and associated with ferruginous matter and
1 U. S. G. S., PP. No. 43, p. 124.
2 U. S. G. S., PP. No. 43.
3 Am. Jour. ScL, 3d series, 33, p. 325.
OXYGEN SALTS 63
chrysocolla. It has been further reported from near
Riverside, by W. B. Smith. 1
Vesuvianite
This is a complex silicate containing calcium, alumin-
ium and a small amount of fluorine. It is frequently
developed in contact metamorphism together with garnet
and epidote. In appearance it resembles the latter min-
eral closely, but may be distinguished from it easily by
the absence of iron ; epidote becomes magnetic on heat-
ing before the blowpipe, while vesuvianite does not.
Samples have been received at the University from the
vicinity of Jerome, but data regarding the mode of oc-
currence are lacking. It doubtless occurs in other
localities in the State, but has not been described or
else has been mistaken for other minerals which it re-
sembles.
Zircon, ZrSi0 4
This mineral has been noted in Arizona in the Clifton-
Morenci district only as a microscopic accessory in granite
and porphyry. 2
Topaz, (AlF) 2 Si0 4
Samples of this mineral have been received at the Uni-
versity from localities in the northern part of the State
in the form of white broken fragments, much re-
sembling quartz, for which it has frequently been
mistaken. It can be easily distinguished from that min-
1 Proc. Colo. Sci. Soc., a, p. 159.
2 Undgren : U. S. G. S., PP. No. 43, p. 102.
64 THE MINERALOGY OF ARIZONA
eral, however, by its superior hardness and its cleavage.
The exact locality of these samples is not known.
Andalusite, Al 2 Si0 5
The silicate of aluminium known as andalusite is devel-
oped in slates and other sedimentary deposits through
the influence of both regional and contact metamorphism.
In rare instances it has been observed as a pyrogenic con-
stituent of igneous rocks. Thus in Arizona it has been
observed as a microscopic accessory in the granites in the
Globe copper district. It has been suggested that possi-
bly the mineral has been developed here through recrys-
tallization brought about by metamorphic action, and is
not an original constituent as it would seem. 1
Cyanite, Al 2 Si0 5
This is a pale blue bladed mineral of the same composi-
tion as andalusite, and though appearing quite different
from it, occurring in a similar manner. In a ground mass
consisting of quartz and mica, it is found north of Yuma
in the form of small stout crystals about one-half inch in
length. In the same locality it is further found associated
with dumortierite.
Epidote, HCa 2 (Al,Fe) 3 Si 3 13
This mineral is a silicate of calcium, iron and alumin-
ium, and can usually be easily recognized by its pecul-
iar yellowish green color. It is abundantly developed in
Arizona as the result of contact metamorphism ; hence it
is found associated with garnet and other products of this
1 Ransome : U. S. G. S., PP. No. 12, p. 66.
OXYGEN SAI,TS 65
action in most of the mining districts. It is further formed
as the result of other secondary decomposition in nearly
all kinds of rocks, both sedimentary and volcanic. It may
appear as greenish incrustations on the surface of rocks
or as filling in minute cracks. In the Tucson mountains
it has been observed as a decomposition product in light
colored rhyolites where it appears as green blotches
through the specimen. Some of the spots are rather an-
gular and are thought to be pseudomorphs after feldspar.
In the same locality it is found in dark andesitic rocks, as
thin incrustations along the joint planes. This mineral
being of such wide occurrence is usually found in the
streams and washes as greenish pebbles, and as green
stains on other fragments. The association of epidote
and native copper has been described under Copper.
Gadolinite
This is a silicate of glucinum, iron, the rare yttrium
earths, and cerium. It is quite abundant in the mineral-
ized pegmatites of Norway and Sweden, but extremely
rare elsewhere. In Texas it has been found in nodular
masses and rough crystals of large size. In 1908 a de-
posit was found near Kingman, Arizona, and several tons
of the material have already been shipped East for the
extraction of rare earths employed in the preparation of
the well-known mantles for incandescent gas light. The
mineral from this locality presents the usual appearance
of dark brown to black glassy masses of conchoidal
cleavage not unlike ordinary obsidian. It has, however,
a very much higher density. It occurs associated with
66 THE MINERALOGY OF ARIZONA
the new mineral, arizonite, in what seem to be pegma-
tites. Mr. Chase Palmer has made a partial analysis,
the results of which are given below. 1
Per cent.
SiO 2 24.41
Yttrium earths 36.86
Cerium earths 11.50
BeO 11.50
FeO 11.56
Calamine, H 2 ZnSi0 5
The hydrous silicate of zinc, or calamine, has been re-
ported as occurring in minute quantities on garnet rock
in the Shannon mine in the Clifton-Morenci districts. 2
Tourmaline
This is a complex silicate of boron, aluminium and sim-
ilar elements. As stout black hexagonal crystals, some-
times bent and faulted it is found in the Catalina moun-
tains near Oracle. It is here occasionally disseminated
through the mass in such a manner as to constitute a
typical tourmaline granite. It is not found in large
masses, however, and is simply a local condition along
the borders of the main granitic material. A microscopic
examination shows it to be associated with quartz, plagi-
oclase, orthoclase and microcline. Tourmaline seems
to be very widely distributed throughout the State as
shown by the frequent samples received for identification
at the University of Arizona. Among these have been
observed frequently fibrous and even granular modifica-
tions of the mineral.
1 Am. Jour. Sci., 28, 353.
* Lindgren : U. S. G. S M PP. No. 43, p in.
OXYGEN SAI/TS 67
Dumortierite
This is a rare silicate of aluminium with a small per
cent, of boron. It is of a beautiful blue color and has fre-
quently been mistaken for copper minerals. It is fre-
quently found in the form of float or loose rounded peb-
bles in the vicinity of Clip, north of Yutna. It is asso-
ciated with rather granular quartzite-like rock highly
metamorphic and sometimes so intimately mixed that
the entire specimen appears blue. Under the microscope
however, thin sections show that the mass is made up of
fine needles and bunches of radiating crystals embedded
in the quartzite. The mineral shows beautiful pleocroism,
the color parallel to the elongation being a deep blue,
while the other two directions give nearly colorless and
pale violet. The quartz is well crystallized, appears in
rounded individuals with sharp contacts and contains
numerous gas and liquid inclusions. The gas bubble is
frequently found to be in motion. The mineral from
Clip has been analyzed by Diller 1 and Ford 2 both of whom
found noticeable quantities of boron oxide. These analy-
ses are of value since they show that the mineral is to be
considered as a compound containing boron and not a
simple silicate as formerly. The Arizona locality is of es-
pecial interest since here the mineral seems to be found
in a metamorphic rock rather than in pegmatites the
more usual mode. The presence of the gas inclusions
prove, however, that the metamorphism is of a deep-seated
type.
1 Am. Jour. Sci., 3d series, 37, p. 216.
* Am. Jour. Sci., 4th series, 14, p. 426.
68 THE MINERALOGY OF ARIZONA
Mica
There are several varieties of mica varying in composi-
tion and appearance, but all possessing the well-known
cleavage and yielding elastic plates.
Muscovite. This variety is the common white mica
and is a frequent constituent of rocks and soils. In large
crystals it frequently developes in pegmatites or the white
vein-like formations seen crossing granite and similar
rock masses. It is further a constituent of metamorphic
schists. Sericite, a closely allied variety has been fully
described by Ransome in the schists of the Bisbee Quad-
rangle, 1 and by the same author in similar rocks of the
Globe district.
Biotite, or the black mica, is similar in composition
with the exception that it contains iron and magnesium.
It is abundant in Arizona as a rock-forming mineral in
the biotite granites, gneisses and metamorphic schists.
Doubtless other varieties of mica are to be found in
Arizona, but as yet they have not been investigated.
Serpentine
This is a hydrous magnesium silicate, a secondary
mineral resulting from the alteration of such minerals
as olivine, pyroxene, hornblende, etc. Such rocks as the
peridotites, which are made up almost entirely of these
minerals, yield on disintegration large deposits of ser-
pentine. It is a rather soft mineral, usually of greenish
color and a slight soapy feel.
i u. s. G. s., PP. NO. 21, p. 25.
OXYGEN SALTS 69
Ordinary Serpentine. Impure massive serpentine is
found associated with magnetite in the Dos Cabesas
mountains. A similar mode of occurrence has been noted
by Lindgren in the Clifton-Morenci district in the
Thompson mine. 1
Chrysotile or Asbestos. This is the crystallized or
fibrous variety of serpentine and is known on the
market as asbestos. It is found in the granite gorge of
the Grand Canon, 4,000 feet below the rim on the north
side of the river, where it is mined by the Hance Asbes-
tos Co. The fibers are of excellent quality, of good
length and very flexible. The mineral occurs in cracks
or seams in the rock where the fibers have arranged them-
selves perpendicular to the surfaces. The asbestos seems
to be associated with limestone which has become altered
through the contact action of intrusive diabase. It is
supposed to have resulted from the hydration of the
pyroxenes. While the material is, perhaps, of the finest
quality of any found in the United States, its inaccessi-
bility makes it difficult to work the deposit with profit. 2
Another locality has been reported from a place twenty
miles west of Globe where it occurs in seams in massive
serpentine.
Talc
This well-known mineral is also a decomposition pro-
duct of ferromagnesium minerals and is frequently met
with in the vicinity of mines where metamorphic agencies
are at work. It is lighter in color and softer than ser-
*U. S. G. S., PP. No. 43.
2 Mineral Resources, 1908.
7O THE MINERALOGY OF ARIZONA
pentine. No unusual or particular interesting mode of
occurrence has been observed in Arizona.
Kaolinite, H 4 A1 2 S1 2 9
Kaolinite, or as it is more commonly known, kaolin is
a secondary mineral resulting from the decomposition of
feldspathic minerals. It is consequently always found
where weathering and erosion are going on and is hence
a constituent of all soils. Only, however, where condi-
tions are favorable for a sorting action in quiet water by
which the fine clayey material is separated from the sand
and gravel, is it found in a comparatively pure state and
in quite large deposits. In Arizona, the debris from the
mountains is brought down by flood waters and periodi-
cally spread upon the plain, a condition very unfavorable
to the formation of deposits of kaolin or clay. Yet these
deposits, further worked over by less flooded conditions,
sometimes give rise to deposits still containing large
amounts of sand, but of sufficient purity to be used local-
ly for the manufacture of red brick, making it possible
for the large towns of the State to have their brickyards
where a product of fair quality is manufactured.
Pure Kaolin. This is frequently met with in the form
of soft putty-like masses in many of the mines where it
has resulted from a kaolinization of the feldspars. In
the Clifton-Morenci district it is reported as accompanying
chalcocite in the porphyry ; in small veinlets in quartz at
the Hombolt, Ryerson and other mines ; in mammillary
masses associated with azurite malachite in the I^ong-
fellow mine. 1 Associated with limonite, it is found in
i u. s. G. s., PP. NO. 43.
OXYGEN SAI/TS 71
large quantities in the Copper Queen mines, where it has
been selected and used as a binding material for the quartz
used in lining the converters.
Graphitic Clay. A large deposit of this variety s of clay
is found about seven miles from Benson. It is black and
closely resembles soft coal. When ground to a fine pow-
der and mixed with water it becomes very plastic. The
black color disappears on burning, the mass assuming a
buff color. The material has been used for the manufac-
ture of pressed brick and is still extensively used in con-
verter plants as a binding material, in Cananea, Bisbee
and other mining localities. The deposit is said to be
almost unlimited in extent. Its composition is illustrated
by the following analysis :
Per cent.
Silica 59.15
Iron and alumina 27. 52
Calcium carbonate 2.82
Water and undetermined 10.51
Cement Clay. Doubtless clays or shales of good quali-
ty for the manufacture of Portland cement could be found
in many places in Arizona were the field throughly pros-
pected. At present, however, high freight rates and
small local markets combine to make the outlook for the
cement industry in Arizona rather discouraging. A
government plant has been in operation at Roosevelt
where the product was used for the construction of the
Tonto dam. The clay found here has the following
composition :
72 THE MINERALOGY OF ARIZONA
Silica 51.91
Iron and alumina 23.70
Lime 6. 10
Magnesia 0.97
Water 13.40
Limestone of good quality to combine with the clay is
found in the immediate vicinity. 1
The writer has investigated clay deposits in the vicinity
of Flagstaff and found material of very satisfactory com-
position for the cement industry. Here it results from
the decomposition of black basaltic and andesitic rocks
and has collected in a depression caused by a series of
lava flows in what is known as Rogers Lake. The deposit
is about 700 acres in extent and varies in thickness from
three feet near the edges to nine feet near the center. It
is yellowish grey, very tough and plastic. Its composition
is as follows :
Per cent.
Silica 52.94
Alumina 1 7.91
Iron oxide .... 9. 23
Lime 1.22
Magnesia . 0.42
Alkalies 2.22
Water, etc 16.34
Total 100.28
A burning test was made on this material using 100
parts of clay to 300 parts of limestone. An excellent
quality of cement resulted.
1 U. S. G. S., Bui. No. 243, p. 87.
OXYGEN SALTS 73
Chrysocolla, CuSi0 3 ,2H 2
This is a light blue compact mineral, much resembling
turquoise, quite common near the surface in many of the
mines in the State. In the Globe district it is known
to be very abundant, where it occurs in veinlets in im-
pure cuprite, in mineralized porphyry, and in associated
oxidized minerals. Very beautiful samples are some-
times found in which the delicate blue mammillary
masses are covered with thin crusts of drusy quartz crys-
tals. The mineral as found in the mines is much
harder than expected from the descriptions in the text-
books. This is because of the silicious matter pres-
ent as impurities; in fact, a great deal of the material
thought to be chrysocolla is in reality quartz or silica
stained with copper minerals.
Lettsomite
This is a rare silicate of copper and aluminium. The
mineral is sky-blue, fibrous and possesses a silky luster.
It has been found in a silicious rock in Arizona in the
form of small seams. 1
(3) PHOSPHATES, VANADATES, ETC.
Apatite, CaFl, Ca 4 (P0 4 ) 3
This is found as a universal microscopic accessory in
both granitic and eruptive rocks. It appears as minute
colorless needles, sometimes tufts, but more often as
isolated crystals in the more basic constituents of the
1 Genth : Am. Jour. Sci. 3d series, 4, p. 119.
74 THE MINERALOGY OF ARIZONA
rock. As shown by chemical analysis, it is probably a
constituent of all soils, its ultimate origin being the
microscopic crystals mentioned above.
Ecdemite
This rare chloro-arseniate of lead has been observed as
soft drusy incrustations on wulfenite crystals from the
Mammoth mine in the Catalina mountains. It is of an
orange color, about the same tint as the wulfenite, and can
hardly be distinguished from it. Under the microscope,
however, the crystallization can easily be distinguished.
Mimetite
This also is a rare chloro-arseniate of lead appearing
usually as pale yellow incrustations consisting of rounded
aggregates. It has been reported from a locality a few
miles northwest of the Vulture mine. 1
Vanadinite, PbCl, Pb 4 (VoJ 3
This rare and beautiful mineral is frequently met with
in Arizona, particularly in quartz veins carrying gold
and silver. In composition it is a chloro-vanadate of
lead, and ordinarily can be easily recognized by its
hexagonal crystallization and its striking red color. It
generally appears as incrustations and isolated implanted
crystals, sometimes barrel shaped, but more often of good
hexagonal development. It is found in the cavities of
the vein filling material, a fact which proves that it was
deposited during the last stages of mineralization. It is
sometimes found even encrusting calcite. Important
localities in Arizona are the Red Cloud mine, Yurna Co.,
* Am. Jour. Sci., 3d series, aa, p. 202.
OXYGEN SALTS 75
the Mammoth mine at Schulz, in the Catalina mountains,
Pima Co., and the OldYuma mine, about 14 miles north-
west of Tucson. Minerals which are most often asso-
ciated with it are, wulfenite, cerussite, ecdemite anddes-
cloisite. In the Globe district, where it is also quite
common, it occurs along prominent fault fissures in the
Apache quartzites. 1 In all of these cases the mineral is
found filling cavities and seams in the country rock in
the immediate vicinity of the vein as well as in the vein
itself. This is especially true of the deposit in the Yuma
mine where good vein filling has progressed to only a
limited extent. Here the vanadinite and associated min-
erals may be found implanted on the surface of planes
formed by fractures in the country rock. Fine museum
specimens are sometimes found which consist of a slab of
the country rock first covered with a layer of calcite, then
vanadinite and finally a thin layer of descloisite. Crys-
tals have been found over one-fourth inch in diameter.
The origin of this mineral or the chemical changes
which have been concerned in its production are points
which have not yet been worked out. Dr. Hillebrand
has called attention to the wide distribution of vanadium
in the rocks of the United States, 2 and the universal
occurrence of apatite with which this mineral is isomor-
phous, as microscopic accessories in rocks, is well-known.
It may be possible then that the mineral originally ex-
isted in minute traces in the apatite molecule in which
case the mineral might easily become concentrated by
1 C. F. Tolman : Private Communication.
2 U. S. G. S., Bui. No. 305, p. 19.
76 THE MINERALOGY OF ARIZONA
simple solution, without the intervention of complex
chemical reactions. The mineral, however, has been
produced artificially by Weinschenk 1 by bringing to-
gether, at moderately high temperatures, chloride of lead
and vanadium compounds. This investigation would
seem to show that if the vanadium originally existed in
the complex basic silicate molecule, reactions with lead
chloride could take place which would give rise to the
mineral.
Libethenite, Cu 3 P 2 8 , Cu(OH) 2 .
This is a green basic phosphate of copper. In has re-
cently been found in the Coronado mine in the Clifton-
Morenci district, as small olive-green crystals less than
one millimeter in length. It is associated with quartz
and needles of malachite. The mineral was identified by
Professor Penfield of Yale and the Caronado mine is
probably the only known locality containing it it the
United States. 5
Descloisite and Cupro-descloisite
These minerals are basic vanadates of lead and zinc
usually containing varying quantities of copper and man-
ganese. In Arizona they are nearly always found asso-
ciated with wulfenite and vanadinite. The most char-
acteristic appearance is that of lustrous bronzy or black
incrustations rarely more than one or two millimeters in
thickness. In some cases the appearance is very much
like that of thin varnish on the surface of other minerals.
1 Brauns : Chemische Mineralogie, p. 270.
2 U. S. G. S. , PP. No. 43.
OXYGEN SAWS 77
They are found deposited on calcite, wulfenite and
vanadinite crystals, and hence are deposited later. Well-
known localities in Arizona are the Castle Dome district,
Tombstone, Mammoth mine in the Catalina mountains,
and the Old Yum a mine in the Tucson range of moun-
tains. The writer has analyzed this mineral from two
widely different localities, the results of which are given
below. No. i was from the Old Yuma mine in the
Tucson mountains, and No. 2 from the Argentine Repub-
lic. No. i appeared as crystalline incrustations on crys-
tals of vanadinite. These were chosen in preference to
the incrustations found on calcite for the reason that it
was believed that possible contamination from this source
would not be so serious as from the calcite. No. 2 ap-
peared as distinct orthorhombic crystals about two milli-
meters in length. Analysis No. 2 was conducted in the
Fresenius Chemical Laboratories in Wiesbaden, and
recognition is due Dr. H. Fresenius and Dr. W. Fresenius
for permission to carry on the investigation as well as
valuable suggestions regarding the method of analysis.
No. I No. 2
Ratios Per cent. Ratios
Cl 0.08
Insoluble.. 0.78
As 2 O 5 o. i r
PbO 52.26 0.2345 53.36 0.2393
CuO 11.64 0.1462 i. 21 0.0152
FeO 0.56 0.0077
ZnO 6.71 0.0824 13.15 0.1615
MnO 2.16 0.0304 4.56 0.0642
V 2 O 5 23.02 0.1262 23.05 0.1263
H 2 O 2.52 0.1400 2.27 0.1261
Total 98.31 99-13
78 THE MINERALOGY OF ARIZONA
Reduced to simpler terms, these ratios become :
No. i No. 2
RO 0.4935 = 4 0.4879 = 4
V 2 O 5 o. 1262 = i o. 1263 = i
H 2 O 0.1400=1 0.1261^1
The formula then becomes (RO) 4 . V 2 O 5 . H 2 O, or,
R 3 (VO 4 ) 2 . R(HO) 2 , which is that usually given to this
mineral.
The method of analysis briefly outlined is as follows :
The finely divided mineral is dissolved in strong nitric
acid, diluted and the insoluble residue filtered off, ignited
and weighed. In the filtrate, chlorine is determined by
means of a standard solution of silver nitrate. The silver
chloride is filtered off after adding a few drops of chlor-
hydric acid to precipitate excess of silver used in titration.
The lead is then precipitated with H 2 SO 4 , removed and
weighed. The filtrate is now evaporated to dryness to
remove nitric acid. Any further precipitate of lead sul-
phate is filtered off and weighed. The solution, properly
diluted, is now precipitated with H 2 S, the precipitate dis-
solved in nitric acid and reprecipitated. It is then dis-
solved again and the copper determined iodometrically.
The two filtrates from the H 2 S precipitation are combined,
oxidized with nitric acid, and the iron, manganese and
zinc separated from vanadium by precipitation with
sodium carbonate twice repeated (three precipitations).
The three filtrates containing vanadium are combined,
evaporated with H 2 SO 4 to remove nitric acid, diluted and
reduced with H,S. After removal of H 2 S by boiling and
passing in CO 2 , the vanadium is determined by titration
OXYGEN SAI/TS 79
with a standard solution of permanganate. The precipi-
tate of iron, zinc and manganese is now dissolved in HC1
and precipitated with NH 4 OH, the precipitate redissolved
and a basic carbonate precipitation of iron made with am-
monium carbonate. The precipitate is again dissolved and
precipitated with NH 4 OH. The iron is then ignited and
determined in the usual wa}'. The three filtrates con-
taining manganese and zinc are combined, the zinc precip-
itated with H 2 S in a very slightly acid solution (with
H 2 SOJ , filtered off and ignited in a Rose crucible with
hydrogen. The manganese is then precipitated with
(NHJ 2 S in an alkaline solution and the MnS ignited in
the same manner as the zinc.
Erythrite, Co 3 As 2 8 .8H 2
This mineral is sometimes known as cobalt bloom on
account of its delicate flower-like tint and frequent radi-
ating structure. It is a very rare mineral but has recently
been discovered near Jerome where it occurs as soft
powder-like incrustations on a dark colored gangue con-
taining disseminated grains of cobaltite. It is of a delicate
pink color as usual but good crystallizations have not
been observed. The deposit is being exploited for the
cobalt and already some of the ore has been shipped to
New Jersey for treatment. Accurate information regard-
ing the mode of occurrence and associations has not yet
been obtained.
Turquoise
Mineralogically this gem mineral is a phosphate of
alumina and copper. Because of its delicate blue color
8O THE MINERALOGY OF ARIZONA
it has been highly prized by the prehistoric people of
western United States and Mexico. It is, therefore,
found in many of the Aztec ruins in Mexico and in
ruins, of perhaps similar origin, in Arizona. It is found
in situ in the Dragoon mountains, on the road between
Pearce and Gleason, where it occurs in a greatly decom-
posed rock, perhaps a kaolinized rhyolite, in the form of
irregular patches and veinlets. When these deposits
were first discovered, there were abundant evidences of
mining in a crude way, doubtless the work of some
Indian tribe or of a prehistoric people. Some implements
were found and evidences of the use of fire employed,
perhaps, for the purpose of breaking up the rock. An-
other important locality is in Mineral Park, Mohave
County. During the last two or three years this dis-
trict has produced considerable material for the market.
Several mining companies are operating in the district,
among which may be mentioned the Arizona Turquoise
Co., Los Angeles Gem Co., Southwest Turquoise Co.,
and the Aztec Turquoise Co. The deposit is found in
certain hills along the west side of the Cerbat range of
mountains, consisting chiefly of gneisses and schists cut
by later granites and porphyries. Is is in these latter
porphyries that the gem material is found. The porphyry
is greatly decomposed in the vicinity of the turquoise.
It would appear that some of the turquoise has been
formed directly from the kaolinized material by the ad-
dition of copper and phosphated material. Gradations
are observed between simply copper stained kaolin to
OXYGEN SALTS 8 1
pure turquoise. An interesting specimen was recently
cut by the Los Angeles Co., which consisted of the letter
Y in blue in a gray matrix. It was formed by the inter-
section of two small veinlets. The stone was sent to a
student at Yale. 1
Nitre, KN0 3
This well-known compound is frequently formed on
old wall, in caves, and on the side of mine shafts, usually
however, in such small quantities as to escape obser-
vation. It is even said to develop in old morters to the ex-
tent of 5 per cent. 2 The writer has observed it associated
with sodium carbonate as a thin white covering on the
surfaces of the overhanging limestone shelves in the
ancient cliff-dwellings of Walnut Canon, about twelve
miles from Flagstaff. The walls of the canon here are
made up of layers of soft and hard limestone, or more
appropriately calcareous sandstone, which has disinte-
grated, yielding a series of shelves that have been very
conveniently utilized as dwellings by the ancient inhabi-
tants of Arizona.
Nitrocalcite
This is a hydrous nitrate of calcium sometimes met
with in limestone caves, where doubtless an interaction
has taken place between the calcium carbonate and bat
guano or other organic compounds. A bacteriological
action may also be concerned in its formation more or
less direct from the atmosphere. It has been reported
1 Mineral Resources, 1908.
2 Dana : System of Mineralogy.
82 THE: MINERALOGY OF ARIZONA
as occurring in the Mammoth Cave in Kentucky. A
sample of this mineral mixed with a large quantity of
earth was received at the University of Arizona during
the summer of 1907 and indentified as calcium nitrate by
Dr. A. E. Vinsonof the Agricultural Experiment Station.
Correspondence with the sender of the sample brought
the following interesting information: "The calcium
nitrate occurs in vents in the Lower Carboniferous Lime-
stone, fissures that cut across the bedding planes and are
therefore perpendicular. There are several of these vents
grouped close together exposed to full view in the railroad
cut facing the Gila river about two miles above Winkel-
man. The face at this spot is a sheer wall about 100 feet
high and the vents filled with the nitrate are visible from
top to bottom. None of them are more than 6 to 8 inches
wide and the nitrocalcite seems to be mixed with red
iron." '
Gerhardite
This is a basic copper nitrate found as a coating of dull
green color, on the cliffs in the Clifton-Morenci district.
It is supposed to have been formed through the action
of atmospheric water on copper salts. 2 It is also found in
the Jerome district associated with cuprite and malachite.
(Dana.) It is a very rare mineral and is never found
except as thin coatings or stains on other minerals.
Colemanite, Ca 2 B 6 O n . 5H 2
An extraordinary occurrence of this mineral has been
1 Private communication from Mr. K. B. Zachn, Winkelman, Arizona.
2 U.S. G. S., PP. No. 43-
OXYGEN SAI/TS 83
reported by Morgan and Tallmon. 1 It is found asso-
ciated with a tar-like substance in a fossil egg found in
the placer deposits of the Gila River.
(4) SULPHATES
Thenardite, Na 2 S0 4
This mineral is the sulphate of sodium and usually ap-
pears as a dull yellow substance soluble in water. It is
found in large deposits in the Verde Valley, Yavapai Co. ,
near Camp Verde, where, mixed with halite, it is said to
have been used as a substitute for salt for cattle and horses.
The deposit is several acres in extent and fifty or more feet
in depth. It is very compact, mingled with clay, and
associated with Mirabilite, halite and glauberite. 2
Glauberite, Na 2 S0 4 , CaS0 4
This mineral resembles the one just described but differs
from it in containing calcium sulphate in addition to
sodium sulphate. As stated above it is found in the Verde
Valley associated with other soluble sulphate and chlo-
rides.
Barite, BaSO,
Barite, or the sulphate of barium, is commonly known
as heavy spar because of its high specific gravity. It
occurs most often as a gangue mineral, accompanying
such sulphides as galena, iron pyrite, etc. It is usually
nearly white in color and quite soft. In the Silver Bell
1 Am. Jour. Sci., 18, 363.
2 W. P. Blake, Am. Jour. Sci., 3d series, 39, p. 44.
84 THE MINERALOGY 0* ARIZONA
district, barite is found as lustrous white aggregates of
crystals associated with blue cubes of fluospar. In the
Quiotoa district it is found in large masses, which on dis-
integration, yield aggregates of disk or shell-like shapes.
They closely resemble shells which have been cemented
together. They are sometimes covered with drusy crys-
tals of calcite, siderite, or other similar minerals. It has
further been observed in white seams in blue limestone
west of the Tucson range of mountains, in the properties
south of the San Xavier Mission, associated with argen-
tiferous galena, and, in fact, associated with a variety of
minerals in many of the mines of the State.
Anglesite, PbS0 4
This is the sulphate of lead and represents the first
stage in the alteration of galena by which cerussite is
finally produced. It being an intermediate product, it
is of rarer occurrence that the carbonate, cerussite.
When pure it is white and transparent, but more often
appears as massive varieties with yellow, gray or nearly
black shades. Samples from the Castle Dome district have
been described and analyzed by Professor Brush. 1 An in-
teresting modification of this mineral came to the writer's
notice several years ago. The specimen came from the
Tombstone district and exhibited pseudomorphous struc-
ture after galena. The sample weighed several pounds
and originally consisted evidently of an aggregate of
cubic crystals. These have altered to the sulphate in
successive stages, giving rise to an appearance that can
1 Am. Jour. Sci, sd series, 5, p. 421.
OXYGEN SAI/TS 85
best be described as alligator-skin structure. The succes-
sive layers about the original galena granule varied in
color from nearly white to dark gray. Small slabs sawed
from this specimen present, when polished, a very pleas-
ing and striking appearance.
Crocoitc, PbCrO,
Chromate of lead is of rather rare occurrence in nature.
It appears as bright red crystals and incrustations very
much resembling vanadinite, but tetragonal in crystalliza-
tion. It is found in the Vulture district associated with
wulfenite and vanadinite. As shown by qualitative tests,
it seems to be quite frequently mixed, isomorphously
perhaps, with wulfenite, and in fact may be the cause of
the deep color of many specimens. Samples from the
Mammoth mine in the Catalina mountains seem to show
a specially large amount of chromium.
Vauquelinite
This very rare phospho-chromate of lead has been re-
ported from the Vulture district, where it is associated
with crocoite and other lead minerals.
Spangolite
This is a basic sulphate of copper and alumina with
some chlorine. It is found in very small quantities in
the Metcalf mine of the Clifton-Morenci district in the
form of bluish flakes and hexagonal incrustations in
sericitized granite-porphyry, associated with cuprite,
brochantite and chrysocolla. 1 It has also been reported
from the Tombstone district.
i Undgren : U. S. G* S M PP. No. 43.
86 THE MINERALOGY OF ARIZONA
Connellite
This is a rare chlor-sulphate of copper of very complex
composition originally occurring at Cornwall. It has
recently been discovered in Arizona in the Calumet and
Arizona mine in Bisbee. It is described as associated
with melanochalcite and chalcophyllite. It was found as
dark blue radiating crystals the largest of which was 0.5
millimeters in length. The mineral was analyzed with
the following results : l
Per cent.
S0 8 3.43
Cl 6.37
CuO 75.95
H 2 O 15.07
Less O Cl 1.42
Total 100.40
Brochantite, CuS0 4 , 3Cu(OH) 2
Many of the green pulverulent minerals of copper, abun-
dant in the mines of northern Mexico and Arizona and
usually classified by the miners as malachite, have recently
been proved to be the basic sulphate of copper or bro-
chantite. Mr. Fred Hawley, a student in the University
of Arizona together with the writer has investigated the
chemical and mineralogical composition of these ores from
the Cananea (Mexico) mines and found that they cor-
respond quite close to the required formula. Mr. Haw-
leys analytical results were as follows :
* Palache and Merwin: Am. Jour. Sci 28, p. 537.
OXYGEN SAl/CS 87
CuO 59-00
SO 8 17-40
H 2 O 10.70
A1 2 O 3 720
FeO and CaO Traces
SiO 2 5.70
The alumina and silica are doubtless due to admixtures
of kaolin, a mineral with which this compound is fre-
quently associated.
Mr. lyindgren has noted brochantite in quite large
quantities, associated with malachite, in the Clifton-
Morenci district, and Mr. Ransome in the Copper Queen
mines at Bisbee. 1
Leadhillite, 2PbS0 4 , H 2 CO,
A rarecarbono-sulphate of lead closely resembling cerus-
site occurring at Schulz, Final Co. (Dana's Text-book.)
Mirabilite, Na 2 S0 4 , ioH 2
This is a soluble sulphate of soda found in the Verde
Valley, associated with thenardite and other soluble min-
erals. It seems to overlie the deposit and penetrate it in
the form of veinlets. 2 It has also been observed as a
white incrustation in the basalt caves near Sunset Peak,
about fifteen miles from Flagstaff. (See Ice Caves.)
Gypsum, CaS0 4 , 2 H 2
Gypsum is a very common mineral and, when favorably
located, is of commercial value in the manufacture of plas-
ters. When burned at proper temperatures it develops
the property of combining again with water and forming
1 U. S. G. S., PP. Nos. 21 and 43.
2 W. P. Blake : Am. Jour. Sci., 3d series, 39, p. 44.
88 THE MINERALOGY OF ARIZONA
a hard compact mass. This property is called ' 'setting'
and the raw burned material as well as the final product
is well known as " plaster of Paris ". Gypsum occurs in
nature in three well-known varieties : the fine grained
white modification or alabaster, the transparent variety
which easily breaks up into thin plates, or selenite, and
the fibrous variety or satin spar. Gypsum is slightly
soluble in water and since it results in the disintegration
of nearly all rocks, through the oxidation of sulphides
and interaction with calcium compounds, it is always
found, in greater or less quantities, in natural waters.
In arid regions like Arizona it is apt to be present in un-
usually large proportions. Where circulating water is not
sufficiently abundant to carry the material away, it is
deposited as a crystallized mineral in the form of impure
gypsum. It is consequently very frequently met with in
mines where sulphides are oxidizing and reacting with
limestone, and where underground water is scarce.
Although abundant oxidation has taken place in the Bisbee
district, gypsum is entirely absent there because of the
transporting action of large volumes of underground
water. 1 In the Clifton-Morenci district where under-
ground waters are less abundant it is of more common
occurrence. 3 These deposits, of course, are not of sufficient
size to be of commercial value, but are interesting from
the fact that they throw light upon the chemical reac-
tions taking place in connection with the deposition of
the ore bodies. Deposits of commercial value are formed
i Ransome : U. S. G. S., PP. No. 21.
* I^indgren : U. S. G. S., PP. No. 43.
OXYGEN SALTS 89
through the evaporation of a lake, pond or arm of the
sea. These beds are therefore frequently depositories of
common salt, and other soluble minerals. Hence it is
found in the Verde Valley associated with thenardite,
glauberite and allied minerals. Other places where it has
been locally used for the manufacture of plaster, are the
low hills along the San Pedro valley, in Fort Apache
Reservation, Navajo County, in the Tucson Valley, and
near Woodruff and Snowflake in the northern part of the
State.
Epsomite, MgS0 4 , 7H 2
As the name indicates this mineral is the natural Epsom
salt or magnesium sulphate. It has been observed as
delicate moss-like efflorescences on the walls of old tun-
nels in the mines of the Clifton-Morenci district. 1
Goslarite, ZnS0 4 , 7H 2
This is the soluble sulphate of zinc. It has been ob-
served in the Clifton-Morenci district in exactly the same
mode of occurrence as epsomite just described. It results
from the oxidation of zinc sulphide and being soluble is
transported and deposited by the evaporation of percolat-
ing water.
Linarite, (Pb,Cu)S0 4 , (Pb,Cu)(OH),
This beautiful and rare mineral is found in the Mam-
moth-Collins mine at Schulz, Pinal Co., associated with
cerussite, wulfenite and other lead minerals. It is deep
blue in color and when mingled with pure white ce-
russite which is also of adamantine luster, presents an ap-
1 U. S. G. S., PP. No. 43, p. 121.
9O THE MINERALOGY OF ARIZONA
pearance of unusual beauty. The crystallization is mono-
clinic, but only one crystal perfect enough to measure
on the reflecting goniometer has been found. The fol-
lowing faces were indentified : a, (100), c, (101), s,
(ooi), y, (201), u, (101), w, (212), m, (no), and r,
(in).
Chalcantite, CuS0 4 , sH 2
This is the well-known blue vitriol or blue stone. As a
mineral it is frequently met with in copper mines,
especially in old workings, where it is frequently found
in incrustations on old timbers and the sides of the tun-
nels, as well as in the form of stalactites hanging from
the roofs of cavities and workings. In some of the old
tunnels of the mines in the Clifton- Morenci district it is
reported as almost filling the opening with stalactitic
masses. 1 In the Jerome district this mode of occurrence
is very common ; indeed, the mine waters are especially
charged with the mineral, so that it is found worth while
to extract the copper by passing the water containing
this mineral in solution, over scrap iron. Fine stalactites,
received from this locality, were nearly two feet in length.
Unfortunately the mineral does not keep well, and the
loss of water of crystallization causes it to disintegrate
and fall to pieces.
Copiatite, 2Fe 2 3 , sS0 4 , i8H 2
This is an unusually rare basic sulphate of iron. A
small specimen from the Mineral Hill district has been
identified at the University of Arizona. It appears as
i u. s. G. s., PP. NO. 43.
OXYGEN SALTS $1
small bright yellow, silky fibers, and slightly foliated
masses, not unlike orpiment in general appearance.
Alunite, K a O, 3A1 2 3 4S0 3 , 6H 2
This mineral is sometimes known as alum stone. It
has been reported as occurring in a narrow seam on a
contact between shale and porphyry in the Ryerson mine
at Morenci. It is further sometimes found associated
with pyrite and kaolin in other parts of the same district.
It is described as sometimes quite clayey in appearance
so that it might easily be mistaken for that mineral. 1
Jarosite
This is usually a ocher-yellow, soft mineral having the
composition of the hydrous sulphate of iron and potash.
It has been reported from the Vulture mine where it oc-
curs associated with gold in quartz. 2
Emmonsite
The composition of this mineral is rather obscure, but
it is thought to be a tellurate of iron with water. It has
been reported from Tombstone as occurring it thin yellow-
ish green scales. 3
Ettringite
This is a hydrous sulphate of aluminium and calcium.
It is of very rare occurrence. The mineral, however, has
been discovered in the Lucky Cuss mine at Tombstone
by Mr. W. F. Stanton and described and analyzed by A.
J. Moses. It is a white fibrous mineral incrusting a sili-
cate of lime and alumina. 4
1 U. S. G. S., PP. No. 43.
2 Am. Jour. Sci., sd series, ai, p. 160.
8 Dana : Text- Book.
* Am. Jour. Sci., sd series, 45, p. 489.
92 THE MINERALOGY OF ARIZONA
(5) TUNGSTATES, MOLYBDATES
Wolframite, (Fe,Mn)W0 4 , and Huebnerite, MnW0 4
These rare and useful minerals have been reported from
several localities in Arizona. The two minerals resemble
each other so closely and gradate one into the other in such
a manner that they can be distinguished only with difficulty
without a chemical analysis. The huebnerite, however,
usually shows a peculiar internal red reflection by which
it can sometimes be distinguished. The two minerals are
of equal value in the steel industries. Wolframite was
first discovered in Arizona in 1896 by Professor W. P.
Blake, then Director of the Arizona School of Mines. It
was described as occurring in grains in quartz and asso-
ciated with gold in the Arivaca district. 1 Perhaps the
most extensively worked deposits are those of the Dragoon
mountains near the Southern Pacific railway station of
Dragoon Summits. The mineral from this locality was
identified at the Arizona School of mines in 1898 as
huebnerite and analyses made by the writer. The com-
position is represented in the following table :
FeO 2.66
W0 3 75.36
MnO 19.50
SiO 2 1.70
Undetermined o. 78
100.00
The mineral occurs in extensive quartz veins, perhaps
of pegmatitic origin, associated with small quantities of
i Kng. Min. Jour., 65, p. 607.
OXYGEN SAWS 93
fluospar and scheelite. The excavation of the vein
material is said to be tmremunerative ; gathering the
float from the canons and washes seem to be more
profitable. Several car-loads of this material were re-
ceived at the University of Arizona from the owners,
Messrs. Stein and Boericke, for the purpose of concen-
tration in the jigs of the School of Mines. The concen-
trates contained nearly 70 per cent, of tungstic acid, while
the tailings assayed but 0.80 per cent. The price of the
material thus concentrated has varied greatly according
to the demand ; the value has fluctuated from $80.00 to
over $400.00 per ton.
Another tungsten locality has recently been opened up
about 80 miles from Kingman, in the Aquerra range.
The mineral is said to occur in grains and in masses
/weighing as much as twenty pounds. 1
Still more recently the mineral has been found in the
Whetstone mountains, about 12 miles south of Benson.
This deposit is unlike any others of this mineral yet de-
scribed. "The deposit is at the base of a steep rise in
granite, which is intrusive in a series of metamorphic
rocks, including siliceous mica, schist and limestone. The
wolframite occurs near the contact of the granite and
schist and in a tongue of granite 60 to 70 feet long and
perhaps half as wide which runs out into the schist. The
granite is very light colored, and except in segregations,
contains no dark constituents. A little wolframite is
found in the quartz vein, accompanied by small amounts
of mica, bornite and probably chalcopyrite. A more
1 Mineral Resources, 1905.
94 TH E MINERALOGY OF ARIZONA
noteworthy quantity of wolframite occurs as segrega-
tions in the granite. " l In places the material is said
to average 10 per cent, tungstic acid, the source being
segregations in the granite very much as biotite and
hornblende are sometimes collected in irregular patches.
The mineral, however, should not be looked upon as an
original constituent of granite, but as the result of peg-
matitic action. Samples from this locality have been
analyzed in the laboratory of the University of Arizona,
by Mr. J. M. Ruthrauff. His results are given in the
table below.
Per cent.
FeO 5.15
WO S 74. 20
MnO 18.09
SiO 2 1.95
Total 99-39
Deposits are further found in Sonora, Mexico, so it
would seem that the zone in which the mineral occurs is
of considerable extent.
Scheelite, CaW0 4
This is the calcium tungstate and occurs as a very
heavy light yellow or amber colored mineral in the same
kinds of formation as wolframite. As mentioned above it
is found in small grains associated with wolframite in the
Dragoon mountains. It is further found as a microscopic
border about the wolframite grains in the whetstone
mountains. 2 It is also found in the Old Hat district in
1 U. S. G. S., Bui. No. 380, p. 164.
* U. S. G. S., Bui. No. 380.
OXYGEN SAI/TS 95
the Catalina mountains, where it is described as occurring
in friable masses of light brown. 1
Wulfenite, PbMoO,
Chemically this mineral is the molybdate of lead. It
is usually found in thin tabular tetragonal crystals vary-
ing in color from nearly colorless to deep red or orange.
In Arizona the deep orange varieties are, perhaps, the
most common. The mineral is found as incrustations,
implanted crystals and as massive modifications sometimes
filling, together with considerable siliceous matter, rather
large veinlets. It is almost always associated with vana-
dinite and other minerals of lead and vanadium. It is
abundant in the Castle Dome district, the Mammoth
mine near Oracle, the Old Yuma mine in the Tucson
mountains and many other localities where it is nearly
always found in quartz veins associated with gold or
silver ores. Interesting samples of this mineral have
been received at the University consisting of very intimate
association of quartz and wulfenite. The sections for
microscopic study have been made of these, and in nearly
all cases it has been found that the silica fills up the
interstices between the crystals of wulfenite showing that
the silicification took place later than the deposition of
the molybdate.
Molybdite
Molybdite, or as it is sometimes called, molybdic ocher,
is a pulverulent yellow mineral, occurring as incrustations
and tufts of small fibers in minute cavities and cracks in
1 W. P. Blake : Rep. to Gov., 1909.
96 THE MINRAI/)GY OF ARIZONA
the vein material. Its intimate association with molyb-
denite or the sulphide, shows without much doubt that
it has resulted from the latter through oxidation and
other chemical changes. Until recently it has been con-
sidered as the trioxide of molybdenum, but the investi-
gations of Mr. Schaller 1 has shown it to be a hydrated
ferric molybdate. Investigations carried on in the Uni-
versity of Arizona further show that the Arizona speci-
mens are also a ferric molybdate instead of the oxide. 2
In Arizona the mineral is found in white milky quartz,
associated with molybdenite and limonite in the Santa
Rita mountains. The composition was found on chemi-
cal analysis to be as follows :
Water 17.35
Fe 2 O 3 21.83
MoO s 60.80
These figures resulted after deducting the insoluble
residue, which consisted of pure quartz, and recalculating
the analysis. The formula deduced from the above fig-
ures is Fe 2 (MoO 4 ) 3 7H 2 O. Mr. Schaller's results give
7j4 molecules of water of crystallization.
1 Am. Jour. Sci., 4th series, 23, 297.
2 Guild : Am. Jour. Sci., 4th series, 23, 455.
VII. NEW MINERALS DISCOVERED IN ARIZONA
Coronadite
This is a new mineral recently discovered by Dr. Hil-
lebrand. Analysis by Dr. Hillebrand show it to be a man-
ganite of lead. It contains 56.13 per cent, of manganese
dioxide and 26.48 per cent, of lead oxide. It is described
as a dark metallic mineral of fibrous structure and altering
to limonite. It is very similar to psilomelane in appear-
ance. It was discovered in the Coronado vein in the
Clifton-Morenci district, and at present is the only
known locality. 1
Morencite
This is another new mineral recently discovered in
the Morenci mines. It is described as a brownish yellow
silky fibrous compound probably resulting from contact
conditions in lime shale. The mineral has been analyzed
by Dr. Hillebrand with the following results : *
Per cen
Si0 2 45.74
A1 2 3 1.98
Fe 2 3 29.68
FeO 0.83
CaO 1.61
MgO 3.99
K 2 O 0.20
Na 2 O o. 10
H 2 O, 105 8.84
H 2 O, 150 0.12
H 2 O Below redness 4.27
FeS 2 0.66
P 2 O 5 0.18
1 U. S. G. S., PP. No. 43.
2 U. S. G. S., PP. No. 43, p. 115.
98 THE MINERALOGY OF ARIZONA
Copper Pitch Ore
This is an ill defined dark brown to black pitchy appear-
ing mineral of copper, found associated with cuprite,
chrysocolla, and other minerals of copper in the Copper
Queen, Morenci and Globe districts. The mineral has
been investigated from time to time but not very conclusive
results as to its real nature have been reached. Perhaps
the most satisfactory investigations are those of Lindgren
and Hillebrand on samples from Clifton. Hillebrand's
analysis gave the following results :
Per cent.
CuO : 28.6
ZnO 8.4
MnO 2 21.2
Fe, Al and P 4.0
Insoluble 22.8
Ignition 13. 7
From the above preliminary analysis of Dr. Hillebrand
the mineral would seem to be some compound of manga-
nese and copper. 1
Quite probably, however, this pitch mineral does not
always have the same composition. Professor Koenig
had examined some of the same or similar material from
Bisbee. As the results of his analysis he considers the
mineral to be a basic salt of orthosilico-carbonic acid.
He has named the mineral Melanochalcite. 2
1 U. S. G. S., PP. No. 43, P. H4.
2 Am. Jour. Sci., 14, p. 404.
NEW MINERALS DISCOVERED IN ARIZONA 99
Arizonite
This is a ferric metatitanite and has very recently been
discovered on the claims of Mr. A. G. Aim, 25 miles
from Hackberry, Arizona. It is associated with Gado-
linite. Mr. Palmer found the composition to be as
follows: 1
Per cent.
FeO 0.70
Fe,0 3 38.38
TiO 2 58.26
H 2 0.18
H S O, 115 1.02
1 Palmer : Am. Jour. Sci. 28, p. 353.
INDEX
PAGE
Actinolite 58
Agate 36
Alabandite 27
Alunite 91
Amethyst 41
Amphibole 5 8
Andalusite . . 64
Anglesite 84
Apatite 73
Aragonite 48
Argentite 24
Arizonite 99
Arsenic 8
Asbestos 69
Atacamite 35
Augite .... 58
Aurichalcite 56
Azurite 55
Barite 83
Biotite 68
Bornite 28
Bournonite ... 31
Brochantite 86
Calamine 66
Calcite 46
Caliche 48
Cement clay 7 1
Cerargyrite 33
Cerussite 55
Chalcantite 90
Chalcedony 36
Chalcocite 25
Chalcophyllite ... 86
Chalcopyrite 28
Chalcotrichite 42
Chrysocolla 73
Chrysolite 61
Chrysoprase 40
PAGE
Chrysotile 69
Cinnabar 27
Clay 70
Cobalt bloom 79
Cobaltite 30
Cohenite 30
Colemanite 82
Connellite 86
Copiapite 90
Copper ii
Copper glance 25
Copper pitch ore 98
Coronadite 97
Covellite . . . 28
Crocoite 85
Cuprite 42
Cuprodescloizite 76
Cyanite 64
Dannemorite .... 59
Descloizite 76
Diamond 5
Diatomaceous earth 37
Dolomite 47
Domeykite 24
Dioptase ... 62
Dumortierite 67
Ecdemite 74
Embolite 33
Emmonsite 91
Epidote 64
Epsomite 89
Erythrite 79
Ettringite 9 1
Feldspar 5 6
Flint 4i
Fluorite 34
Footeite 35
IO2
INDEX
PAGE
Gadolinite 65
Galena 25
Garnet 59
Gehardite 82
Glauberite 83
Gold 9
Goslarite 89
Graphite 8
Graphitic clay 71
Gypsum 87
Halite 33
Heavy spar 83
Hematite 44
Hessite 35
Hornblende 58
Huebnerite 9 2
Hyalite 42
Ice 43
lodobromite 34
lodyrite 34
Iron 14
Iron pyrites . 29
Jasper 40
Jarosite 91
Kaolin 70
I^eadhillite 87
I,ettsomite 73
I^ibethenite 76
limestone 46
I<imonite 45
Iinarite 89
Magnetite 45
Malachite 55
Marble 48
Meteoric iron 14
Mexican onyx 48
Mica 68
Microcline 57
Mimetite 74
Mirabilite 87
PAGE
Molybdenite 23
Molybdite 95
Morencite 97
Muscovite 68
Nitre 81
Nitrocalcite 81
Olivine 61
Onyx, Mexican 48
Opal 42
Orthoclase 56
Peridot 61
Petrified wood 38
Plagioclase 57
Platinum . . 14
Polybasite 32
Proustite 31
Pyrargyrite 31
Pyrite 29
Pyrolusite 45
Pyrope 60
Pyroxene 58
Quartz 36
Rhodochrosite 55
Ruby, Arizona 60
Scheelite 94
Schreibersite 30
Semi-opal 42
Sericite 68
Serpentine 68
Siderite 54
Silver n
Silver glance 24
Spangolite 85
Specular iron 44
Sphalerite 26
Stromeyerite 26
Sulphur 8
INDEX
103
Talc 69
Tenorite 43
Tetradymite 23
Tetrahedrite 31
Thenardite 83
Topaz 63
Tourmaline 66
Tremolite 58
Turquoise 79
Vanadinite 74
Vauquelinite 85
Vesuvianite 63
Willemite 62
Wolframite 92
Wollastonite 62
Wulfenite 95
Zircon 63
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