24 C3 A3 ">v>.87-88 CALIFORNIA STATE MINING BUREAU FERRY BUILDING, SAN FRANCISCO FLETCHER HAMILTON State Mineralogist San Francisco BULLETIN No. 87 January, 1920 The Commercial Minerals of California WITH NOTES ON THEIR USES, DISTRIBUTION, PROPERTIES, ORES, FIELD TESTS, AND PREPARATION FOR MARKET BY W. O. CASTELLO 2484 CALIFORNIA STATE PRINTING OFFICE SACRAMENTO 1920 LIBRARY UNIVERSITY OF CALIFORNIA DAVIS r'i*^^?"/f' IT CONTENTS. Page LETTER OF TRANSMITTAL — 8 PREFACE ^ 9 ALUMINUM — . 12 ANTIMONY 14 ARSENIC — 16 ASBESTOS 17 ASPHALT AND BITUMINOUS ROCK 19 CARIUM-BARYTES 20 BISMUTH 22 BORAX 24 ("ADMIUM 25 lEMENT AND LIME 1 26 CHALK 28 CHROMIUM — — 28 CLAY, POTTERY, BRICK, AND TILE 31 COAL 32 COPPER 33 CORUNDUM AND EMERY 36 DOLOMITE 37 FELDSPAR -_ 38 FLUORSPAR AND CRYOLITE -- 40 lULLER'S EARTH -- --_ 41 GEMS --- 42 GOLD — .- 44 GRANITE 45 GRAPHITE 46 GYPSUM — 48 INFUSORIAL AND DIATOMACEOUS EARTH 49 IRON 50 LEAD - ; 53 MAGNESITE — 55 MANGANESE 57 AfARBLE — 59 MICA AND LITHIA 60 MINERAL PAINT 62 MINERAL WATER 62 MOLYBDENUM — ^ 63 MONAZITE _— _- 66 NATURAL GAS -- 67 NICKEL 68 NITRATES -- 70 PETROLEUM 72 PHOSPHATE ROCK — _ 72 PLATINUM — 74 POTASH — 7G 6 TABLE OF CONTENTS. Page PUMICE AND VOLCANIC ASH 78 PYRITES — 79 SULPHURIC ACID — — 81 QUICKSILVER 81 SALT 82 SANDSTONE — 84 SILICA (SAND AND QUARTZ) 84 SILVER - 86 SLATE — 86 SODA 87 STONE, MISCELLANEOUS 89 STRONTIUM 90 SULPHUR 92 TALC-SOAPSTONE —. 94 TIN 95 TUNGSTEN — --_ — 97 VANADIUM 99 ZINC — _-__ 101 PHYSICAL PROPERTIES OF MINERALS 105 APPARATUS FOR TESTS 108 BIBLIOGRAPHY — 110 PUBLICATIONS OF THE STATE MINING BUREAU 117 INDEX -- — 121 LETTER OF TRANSMITTAL. January 15, 1920. H0NOR.VBLE William D. Stephens, Governor of the State of Calif arnia, Sacramento, California. Sir: I have the honor to transmit herewith Bulletin No. 87 of the State Mining Bureau, entitled ''The Commercial Minerals of California." This bulletin is the compilation of a series of articles which were prepared in the form of w-eekly press bulletins sent to representative newspapers throughout the state beginning June, 1918, for the purpose of giving practical information on California's great variety of mineral products and to stimulate production during a time of need. It is believed the data is of sufficient value to warrant its publica- tion in this form, for general distribution to the public, w^ho may be interested in the development of our raw^ materials. IS Respectfully submitted. P Fletcher Hamilton, State Mineralogist. PREFACE. The headquarters of the California State Mining Bureau are located on the third floor of the Ferry Building, San Francisco, and consist of the administrative offices of the State Mineralogist, State Supervisor of Petroleum and Gas, Library, Mineral Museum, and other offices necessary for carrying on the work of the bureau. Field branches have been established at the following points: Los Angeles (512 Union League Building), Santa Paula, Santa Maria, Bakersfield, Taft, Coal- inga. East Auburn, and Redding. The institution is supported by legislative appropriation, and is under the direction of Fletcher Hamil- ton, State Mineralogist. Its purpose is to promote the interests of the mineral industry in California in every possible way. This object is accomplished by various means, briefly outlined as follows: PUBLICATIONS. Bulletins, reports, and maps, covering all phases of the mining indus- try of the state, compiled as a result of the work of mining engineers and geologists in the field, are available for reference and distribution upon application at this office. It is possible to distribute some of these publications free of charge, but for those more elaborate and detailed a nominal price is asked. (See list of publications, page 117.) GENERAL INFORMATION BUREAU. An information desk is manitained at the main office of the Bureau in the Ferry Building, and the entire staff of assistants is at the service of the public at all times in this regard. All personal and written inquiries relative to any phase of mining or the occurrence of mineral substances in California, are given careful and immediate attention. LIBRARY. The Bureau Library contains over 5000 volumes of selected works including government, state and individual reports on mines and mining and allied technical subjects, as well as files of the leading technical magazines of the world, together with the current copies of the local papers from the majority of the mining camps of California. Here may also be found for reference count}' maps, topographical sheets, geo- logical folios, etc. A reading room is maintained in conjunction with the Library, and both are open to the public daily from 9 a.m. until 5 p.m., except Sundays and holidays; and from 9 a.m. to 12 m. Satur- days. LABORATORY. Samples limited to three at one time, of any mineral found in the state, may be sent to the Bureau for identification, and the same will be classified free of charge. The Bureau is not authorized to make deter- 10 CALIFORNIA STATE MINING BUREAU. minations on samples received from points outside the state. It must also he understood that no assays or quantitative analysis can be made. Samples should be in lump form if possible, and marked plainly with name of sender on outside of package. No samples will be received unless delivery charges are prepaid, and a letter should be forwarded at the same time, stating the general locality where the mineral was found. and the exact nature of the information desired. The work of this department is especially reliable, and many thousand prospectors and others have taken advantage of the assistance which is offered in this manner. MUSEUM. The Museum, which occupies the entire north wing of the third floor of the Ferry Building, with a floor space of 7500 scjuare feet, is one of the finest in the country. A complete mineralogical study of California may be carried on from the 20,000 mineral specimens to be seen, attractively arranged in this immense exhibit. Aside from its purely scientific interest the Museum daily attracts throngs of tourists and sightseers, and has accomplished a great deal in the w^ay of giving visual evidence of California's A^ast mineral resources. STATISTICAL DEPARTMENT. Since 1894 the Bureau has annually issued a special bulletin covering in detail the actual mineral production of the state for the preceding year. Data covering the amount and value of the yearly output is received by the statistical department from every individual mineral operator in California, and these returns, when classified and published in county totals, give the clearest possible conception of the various sections of the state, and have proven in the past to be of great aid to prospective investors and others interested. It is to the undoubted interest of every owner and operator of a mineral property in Cali- fornia to cooperate with the Bureau in its efforts to collect reliable and authoritative statistical data. DEPARTMENT OF PETROLEUM AND GAS. This department was established by law August 9, 1915. It is under the general jurisdiction of the State Mineralogist, who is authorized to appoint a supervisor and engineer or geologist experienced in the development and production of petroleum. It is the duty of the super- visor to supervise the drilling, operation, maintenance and abandonment of petroleum or gas wells, so as to prevent damage to these deposits from infiltrating water and other causes. It is of vital interest to the general public that waste of the natural supply of petroleum and gas in California be prevented, and it is believed that the farsightedness of the framers of this law has been inlly exemplified in the short time COMMERCIAL MINERALS OF CALIFORNIA. 11 which has elapsed since the work in this department was first inaugu- rated, on account of the practical results which have followed it. Much of the damage caused in the past has been due to lack of knowledge of imderground conditions. Information in this regard is being constantly Lrathered and systematized by the Bureau, and the result placed at the disposal of the oil operators. WAR ACTIVITIES. Soon after our declaration of war with Germany it became apparent that this country would be thrown upon its own resources for many mineral substances which, in the past, had been largely imported. The war program for increased construction and manufacture also made necessary a great increase in the production of many minerals, ores and structural materials which had for some time been produced in quantities only approximately equal to pre-war consumption. Since California produces a greater number of commercial mineral substances than any other state in the Union, and was one of the fore- most producers of several of the war minerals, a large responsibility was thrown upon the miners and producers of this state. Among other things which the State Mining Bureau undertook in order to bring the situation more forcibly to the attention of those directly concerned, and to stimulate production, was the preparation of weekly articles, each dealing with some mineral substance which has been produced or found in California. These articles were sent to newspapers in every section of the state, for publication, and extra copies were kept on file at the main office and the several branch offices of the Alining Bureau, for free distribution. They also served in answering many inquiries, both personal and written in regard to general information as to demand, production, price, etc., of the many minerals dealt with. The data given does not pretend to be more than a compilation of available material from many sources, presented in a way intended to irive concise and practical information to the prospector, miner, pro- ducer, or anyone interested in the mineral industry. Publications of the United States Geological Survey have been freely drawn upon for figures relative to total production, imports, etc., as well as other general information; also numerous reports and bulletins of the State Mining Bureau, as well as the standard text books on the sub.iects, all mentioned hereafter in the bibliography. Note — When the material was sent out in the form of weekly articles, informa- tion relative to demand, production and value of the various minerals was included; but all three factors are constantly changing. Up to date data covering these facts may always be obtained from the Bureau's annual statistical report, wh'ch is distributed free of charge. It is therefore suggested that those interested in demand, production, or value, provide themselves with the latest statistical report, a copy of which will gladly be forwarded to any address immediately upon request. 12 CALIFORNIA STATE MINING BUREAU. ALUMINUM. The most important domestic consumption of aluminum in the past few years was directly or indirectly in the war industries. It was used in a great variety of forms, in the manufacture of war apparatus. There has been no production of aluminum in California, although small deposits of impure raw material have been reported. Approxi- mately 70% of the nation's output is used in the manufacture of aluminum, the remainder being utilized in making chemicals, salts, abrasives and refractories. Although the domestic consumption has greatly increased, the home deposits have apparently been able to supply the demand, leaving some ore for export. The principal markets are east of the Mississippi. Industrial application and uses. Aluminum is used in the manufacture of aeroplanes, ships, auto- mobiles, and a great many other appliances, in the form of castings, plates, metallic parts and fittings, drawn and pressed wire and pro- tective coatings. In many small ways it goes into the makeup of the soldier's equipment. Aluminum powder is used to some extent in high explosives. A great amount is consumed in the manufacture of cooking, household and industrial utensils, scientific apparatus, surgical instruments and various alloys. Most of these uses are due to the properties of lightness and resistance to the action of the atmosphere. Aluminum salts, such as aluminum and sodium alums, aluminum sulphate and aluminum chloride are also made in the United States. Some of these are used in making baking powder and dyes. Properties and ores. The pure metal aluminum is bluish white in color, has a metallic lus- ter and is very light, its specific gravity being 2.6. It is very ductile and malleable, may be cast and welded, is a good conductor of heat and electricity and is not readily oxidized in the air. The principal commercial ore is bauxite, a hydrous oxide of alum- inum (AUO3. 2II2O). Contains 73.9% AUG, + 26.1% H.O. It resem- bles ordinary clay, being white, yellow, brown or red in color, very soft (hardness 1.5) and quite light (gravity 2.5). Massive and earthy in structure and commonly impure through the presence of iron oxides, silica, lime and magnesia. It received its name from the village of Px'aux in France, where it was found in 1821. I COMMERCIAL MINERALS OF CALIFORNIA. 13 Distribution. Although aluminum does not occur free in nature, its compounds are numerous and widely distributed. It is the most common of the metals, making up about S% of the earth's crust. Many common rocks and minerals are silicates and oxides of aluminum, with other metals. Clays and slates are mainly silicates of aluminum formed by the decomposition of other minerals. The common feldspars con- tain from 20% to 35% aluminum. Corundum is aluminum oxide (AloOg) and the precious stones, ruby and sapphire, are varieties of this mineral, the color being given by oxides of the other metals. The precious stones, topaz, amethyst, and Oriental emerald are silicates of aluminum. Although the metal is so widely distributed in these various minerals mentioned, it is not produced commercially from them. As previously mentioned, pure deposits of the commercial ore bauxite have not been found in California. Impure varieties have been found in Yuba and Riverside counties. The known commercial deposits in the United States are in Arkansas, Alabama, Georgia and Tennessee. In general occurrence it is closely associated with kaolin or claj', and is derived from the alteration of syenite or the action of circulating waters on shales, limestones, and quartzitic rocks. Tests. Infusible aluminum compounds, or minerals, when moistened with cobalt nitrate and intensely heated before the blow pipe, assume a line blue color. The mineral should be powdered and heated either on charcoal or on the loop of a platinum wire. Ammonia, when added in excess to an acid solution containing aluminum, precipitates gelatinous aluminum hydroxide. Bauxite may be tested by the first method given. It is insoluble or only slightly soluble in hydrochloric acid. Preparation. Aluminum is produced by treating AL.Og (purified bauxite) with an electric current, in a fused bath of cryolite (AlgNgGFjo). The process is carried on in large iron pots with thick carbon lining. Bauxite is purified by heating with soda, forming a soluble alum- inate. The ferric-oxide contained in the ore is unaltered. 3Na,C03+AUO,=2Na3A10,+3CO,. The mass is washed on a large filter, and the pure Al(OH);j pre- cipitated from the solution by agitation with carbon dioxide (CO;,), obtained from limestone. This Al(HO).., after settling, is washed on a filter or in a centrifugal machine. 14 CALIFORNIA STATE MINING BUREAU. In the Bayer process a solution of sodium aluminate is prepared, and by stirring powdered aluminum into this a crystalline precipitate of aluminum hydroxide separates, the impurities remaining in solu- tion. Under certain conditions, when powdered bauxite is added to this solution and stirred vigorously, more aluminum is dissolved out of the bauxite, and a cycle of operations result. ANTIMONY. The demand for antimony in the United States has in the past been almost entirely supplied by imports, mostly from China, Japan. ^Mexico and Europe. Deposits of this metal in California have been one of the dormant mineral resources of the state. Occasionally a small production has been reported; none, however, appeared from 1902 to 1915. With the beginning of the war and the increased demand for antimony in the manufacture of munitions, prices rose from a normal of 7^ or 8^ per pound for the metal to 40^ per pound at the end of 1915. This re- newed interest in known deposits in this state and stimulated the search for new ones, and the result was a small production in 1915, 1916 and 1917. Industrial application and uses. In the war industries antimony is used with lead in the manufacture of bullets, shrapnel, etc. Its function is to harden the lead. Anti- mony sulpbide is used in smoke bombs and primers of shells and cartridges. In peace times its greatest use is in the making of alloys such as type metal and anti-friction metals, because of its peculiar property of expanding when cooling from a molten state, thus insuring sharp, clean-cut edges. Some of its compounds are used in the manu- facture of color pigments and paints and in medicine | Properties and ores. Native antimony (Sb.) is a tin-white metal with a fine metallic luster, generally massive, but sometimes granular, has a distinct lam- ellar structure and perfect basal cleavage. It is very brittle and heavy (specific gravity 6.6-6.7), but not hard (hardness 3.0-3.5). Stibnite (SbgSa), antimony sulphide, is the common ore of antimony. Contains 71.4% antimony and 28.6% sulphur. It is lead-gray to dark-gray in color, with dark-gray streak. Has a metallic luster, per- fect cleavage and uneven fracture. Very soft (hardness 2.0) ; specific gravity 4.5-4.6. Generally occurs in long prismatic crystals often COMMERCIAL MINERALS OF CALIFORNIA. 15 bent or curved with faces striated or furrowed. Sometimes occurs massive or granular. Distribution. Antimony in very small amounts is a constituent of many minerals and ores. Thus widely distributed it is of no commercial value and is often a detriment to the treatment of ores for other metals. Stibnite occurs in veins in granite and metamorphic gneisses and schists, and is closely associated with the common sulphides of lead, zinc, copper, and iron, i. e., galena, sphalerite, chalcopyrite, pyrite and tetrahedrite. It is also often associated with mercury and arsenic. It occurs in gold-bearing quartz veins and has a strong tendency to form replacements in limestone and shale. Its decomposition near the surface results in various yellowish and white oxides. The better known deposits in California are in Kern, Inyo, River- side, San Benito, and Santa Clara counties. It has been found in ^Mariposa, Merced, Mono, Nevada, Sierra and Calaveras counties also. Tests. Stibnite fuses readily in the flame of a candle, and when heated before the blowpipe on charcoal, is absorbed, giving off white fumes which have no distinct odor, and which form a white coating on the charcoal. When heated in the open tube, oxides of antimony are formed and deposited on the sides of the tube, sometimes as a ring near the heated part and sometimes all along the under side of the tube, and often dense white fumes are given off. When treated with concentrated nitric acid a white substance is formed which is very insoluble in water. Metallurgy. Stibnite is either: (1) reduced directly by metallic iron; or (2) roasted to oxide, and then reduced by charcoal. The ore is ground fine, mixed with iron scrap and turnings, and salt or salt cake, and put into crucibles each holding about 60 pounds. Scrap iron is placed on top and the crucibles are then placed in a long, narrow reverberatory furnace. The salt acts as a flux. SboSg + 3Fe = 2Sb + 3FeS. The product, after removal from the furnace, contains several per cent of iron, and this is removed by a second heating with clean stibnite. The sulphur is removed by a third heating with potash or soda. In the other method the ore is simply roasted to oxide: 2Sb.S3 -f 90. = 2Sb203 -[- 680^ and this reduced by heating with charcoal: 2Sb,03 + 3C = 4Sb -f SCO,. 16 CALIFORNIA STATE MINING BUREAU. ARSENIC. Arsenic was first produced in the United States in 1901 from a plant at Everett, Washington. Industrial application and uses. Arsenic is used in the form of arsenious acid (AS0O3) in dyeing and printing cloth, in the manufacture of pigments, soaps, and other salts of arsenic, and in preserving skins of animals and birds. The metal is used to harden lead in making bullets, shot, etc.. and to some extent in other alloys. Properties and ores. Arsenic occurs free in nature as a brittle, tin-white or steel-gray metal. When freshly broken it has a metallic luster, but tarnishes quickly to almost black in moist air. Hardness 3.5, specific gravity 5.6-5.7. When heated in the air it volatilizes, giving off a garlic odor. Occurs associated with antimony and ores of gold and silver. The arsenic of commerce is rarely obtained from the metal, but from arsenopyrite, while the commercial arsenious acid is obtained as a by-product in the extraction of nickel, cobalt and silver from their ores. Arsenopyrite (FeAs^) Arsenical pyrites. Called also mispickel. Color silver-white or steel-gray, metallic luster, brittle, hardness 5.5-6.0, specific gravity 5.9-6.2. Contains 46% arsenic, 19.7% sulphur and 34.3% iron. Occurs generally in crystalline rocks, associated with ores of silver, gold, tin and lead. Realgar (AsS) and Orpiment (AS2S3), sulphides of arsenic, although not used as ores of arsenic, have a certain commercial value. Realgar is orange yellow to red in color, resinous luster, hardness 1.5-2.0, specific gravity 5.7. Contains 70.1% arsenic and 29.9% sulphur. Orpiment is lemon yellow in color with properties similar to realgar and contains 61 9^ arsenic and 39% sulphur. The minerals are closely associated and usually found together. Realgar is used for pyrotech- nic displays, yielding a brilliant white light, while orpiment is used in dyeing and in a preparation to remove hair from skin. Distribution. Arsenopyrite is a common vein mineral in the state and is often gold bearing, in fact in some gold districts it is the chief gold ore. It has not yet been used in California, however, for the production of arsenic. Realgar has occasionally been found in California associated with other ores, but it is very rare. COMMERCIAL MINERALS OP CALIFORNIA. 17 Tests. When arsenic or its sulphides are heated on charcoal before the blowpipe, the arsenic volatilizes, combines with oxygen of the air forming AS2O3, which condenses as a white coating on the charcoal some distance away from the assay. When heated in the reducing flame, the fumes given off have a disagreeable garlic-like odor which is very characteristic and easily recognized. When heated in the open tube the white sublimate condenses as a ring on the sides of the glass. The coating is volatile and disappears when heated. Arsenopyrite fuses before the blowpipe to a strongly magnetic globule. Realgar and orpiment when heated in the closed tube give a deep red almost black liquid sublimate when hot which becomes a reddish yellow transparent solid when cold. Metallurgy. Metallic arsenic is obtained from arseno-pyrite by a combined system of retorts and condensers. A simple decomposition takes place. FeAsS = FeS + As White arsenic (AsoOg) is obtained by roasting either arseno-pyrite or the flue dust, resulting from the smelting of certain lead, copper or tin ores. ASBESTOS. The production of asbestos in the United States is far less than the demand. The output in California has been very small and intermit- tent. A great portion of the world supply comes from Canada. Industrial application and uses. The greatest and most common use for asbestos is in making fire- proof material, such as theater curtains, firemen's clothing, wrappings for steam and hot water pipes, furnace linings, packings for pistons and cylinder heads, and small household articles. It is also ground and made into cements, paints, brick, tiling, plaster, flooring, roofing and insulating material. Properties and ores. In its original sense asbestos was a fibrous variety of the mineral amphibole. a metasilicate of calcium, magnesium and iron. As now used the term includes tremolite, and actinolite (amphiboles), and chrysotile, a hydrous silicate of magnesia, being a fibrous form of serpentine. 2-24S4 18 CALIFORNIA STATE MINING BUREAU. Amphibole asbestos possesses high refractory properties, but lacks strength of fibre and is used mainly for covering steam pipes and boilers, while chrysotile fibres are often of silky fineness, and have greater strength and elasticity and may be spun into threads or woven into cloth. To bring the highest market price, asbestos must possess the following properties : toughness or tensile strength, inf usibility, flexibility, length and fineness of fibre. The most important of these are toughness and infusibility. It must be kept in mind that the length of fibre, the characteristic that most strongly appeals to the eye, is not the final test for the commercial value of the ore, but given samples of equal quality otherwise, the ore with the longest fibre will of course be the most valuable. As found in nature asbestos is white, gray, green or yellow in color, generally soft (hardness 2.5-5.0) and light (specific gravity 2.5-2.6). It has a greasy luster and feels smooth and greasy. The fibrous structure is its most striking characteristic. Distribution. Asbestos of various grades is widely distributed in California, but the deposits have been considered mostly of such low quality, that the material has not been marketed. Commercial production has been made in Alameda, Calaveras, Inyo, Nevada and Shasta counties. One firm has a\, grinding and fibreizing plant in Oakland, and a new mill has recently been put in operation at Washington^, in Nevada County. The greater part of the United States supply comes from Quebec, Canada, where there are large deposits of excellent quality and all grades. This supply is so convenient that it has tended to delay the development of home deposits. Production has been made to some extent in Arizona, Georgia, Idaho and Virginia. Tests. Asbestos is readily distinguished by its fibrous structure, infusibility and other physical characteristics described under Properties. The hydrochloric acid solution, if dilute, gives an abundant precipitate with sodium phosphate (test for magnesium). Preparation. The longer more flexible fibres are spun or woven into cloth, while the short non-elastic material is ground and pressed into sheets, or bricks, or used for paint, etc. i COMMERCIAL MINERALS OF CALIFORNIA. 19 ASPHALT AND BITUMINOUS ROCK. Before the oil industry grew to such proportions in California, asphalt was produced from outcroppings of oil sands, and was rated as a separate industry. In the last few years, however, almost all of the asphalt has come from the oil refineries, which produce a more uniform product of better quality than is found in natural deposits. The production of asphalt from 14 refineries in California in 1917 was approximately 220,300 tons, valued at $2,100,252. This is the largest producing state in this regard, as the crude oils are almost entirely of asphalt base. The refinery of the Standard Oil Company at Richmond, Contra Costa County is the largest in the world. The natural asphalt that is mined at present is in the form of bituminous sandstone, used for road material. The production in 1918 was from one quarry each in Santa Cruz, San Luis Obispo and Santa Barbara counties, and amounted to 2561 tons, valued at $9,067. Other important producing states are Texas, Oklahoma, Utah, Ken- tucky and Colorado. Large quantities are annually imported from Trinidad, one of the West India Islands, and from Venezuela. The war stimulated domestic markets for asphalt material derived from crude petroleum, and for imported asphalt, but the abundance of these materials has lessened the demand for native bitumens and for various types of bituminous rock produced in this country. Industrial application and uses. Bituminous rock is used principally as a road-building material. Other varieties of natural asphalt are used in the manufacture of roofing material, paints, varnishes, rubber substitutes and paving cements. Some natural asphalts are used directly as paving and road surfacing material. Properties. The hydrocarbons, as the name implies, are composed of hydrogen and carbon in widely varying proportions. The term includes a large group of materials ranging from the gaseous state, such as marsh gas, or natural gas, through the liquids, as petroleum and its products, to the solid coals. Bitumen, as commonly used, is a somewhat narrower term, which, while it may embrace all the hydrocarbons, is generally applied to the semi-solid or viscous materials, as asphalt, tar and heavy oils. Asphalt is a dense, black, heavy, semi-solid material, one of the products from the refining of crude petroleum. Layers of bitumen and seepages of viscous tar-like matter are com- mon in the Monterey and San Pablo shales and sandstones, and are found in commercial quantities where these formations are exposed. 20 CALIFORNIA STATE MINING BUREAU. Tests. Asplialt and bituminous material can be readily distinguished by the ease with which it burns, and by its soft, black, oily or pitch-like appearance. When in the harder or more compact state it has a prominent conchoidal fracture. Has a distinguishing bituminous odor and taste. BARIUM-BARYTES. The barium industry in the United States has shown a remarkable growth in the past few years. This increase was due to the establish- ment of the barium chemicals industry in the United States, the in- creased manufacture of lithopone, greater use of ground barytes, particularly in the rubber industry, and the curtailment of imports. The imports before 1914 were in large part from Germany and aver- aged around 25,000 tons annually. In 1917 and 1918 there were practically no imports. industrial application and uses. The principal barium products are ground barytes, barium chemi- cals, and lithopone. Ground barytes is used, in making ready mixed paints, in the rubber industry, and in making stiff heavy cardboards and papers. The production of various barium salts and chemicals has greatly increased in the last few years. The principal chemicals are barium binoxide, barium carbonate, barium chloride, barium nitrate, and barium sulphate. They have a wide variety of uses and enter into the manufacture of other products. Barium binoxide is used in the manufacture of hydrogen peroxide and in the preparation of oxygen. The chloride and carbonate are used in the preparation of other chemicals, in making rat poison, as a water softener, and in the preparation of flat wall paints. The nitrate is used in explosives, fire works, signal lights, etc. It produces 'green fire.' The chlorate is also used in pyrotechnics. The sulphate is extensively used in the paint industry, and also in making paper, putty, and rubber. Litho- pone is used as a pigment in the manufacture of wall paints and rub- ber goods. Minor uses are in the preparation of enamel, calcimine and paper. Properties and ores. Barite (BaSO^) Barium sulphate. It is the most common barium mineral. Contains 65.7% BaO and 34.3% SO3. Called heavy spar because of its weight (specific gravity 4.3-4.6). Color pure white to yellow or brown, vitreous luster, sometimes pearly, cleavage perfect basal and good prismatic. Hardness 2.5-3.5. Occurs massive and granular or as tabular prismatic crystals. COMMERCIAL MINERALS OF CALIFORNIA. 21 Witherite (BaCO.,) Barium carbonate. Contains 77.7% BaO and 22.3% CO2. Color white to gray or yellow, transparent or translu- cent, luster vitreous or slightly resinous, imperfect cleavage. Hardness 3.0-3.7, and specific gravity 4.3. Occurs massive, granular or fibrous. Distribution. Barite is one of the common minerals of the state. It is a common gangue mineral in vein deposits and is especially associated with galena, and therefore prominent in silver-lead districts. The produc- ing properties are located in Mariposa and Monterey counties, and it is also known to occur in Inyo, Los Angeles, San Bernardino and Santa Barbara counties. The deposit at El Portal in Mariposa County lias given the largest commercial production to date. Witherite is frequently associated with barite, but usually in small amounts. The deposit at El Portal is the onl}^ one of record in the United States from wliich commercial quantities of the carbonate have been shipped. Total production in California in 1918 was 100 tons valued at $1500 as compared with 4420 tons valued at $25,633 in 1917. Of the states, Georgia and ^Missouri are the largest producers, al- though considerable tonnage is produced in Tennessee, Kentucky and Alabama. Tests. The barium minerals are most readily distinguished by their great weight. They give a yellowish-green color to the flame, which is intensified by moistening the mineral with hydrochloric acid. With the exception of the silicates, barium minerals when intensely heated before the blowpipe and placed on moistened turmeric paper will turn it red (alkaline reaction). Barite is insoluble in water or acids, while witherite will bubble and eifervesce upon the application of hydro- chloric acid. Witherite may be readily distinguished from strontianite, which it resembles, by the flame test. Preparation. In the preparation of ground barytes, the crude material is first crushed to about one inch size, and then washed in jigs or similar inachines to remove the clay, calcite, silica, iron oxide, etc. It is then ground fine and bleached by treating with sulphuric acid for 8 to 12 hours in lead-lined tanks. The bleaching process is a very important one, as the product must have a perfectly uniform color. After bleaching it is washed several times and then pulverized to pass a 200 or 300 mesh screen, and in some cases is water floated to insure a uniformly fine product. It is then dried and packed. 22 CALIFORNIA STATE MINING BUREAU. Lithopone is a mixture of about 70% barium sulphate, 25 to 29% zinc sulphide and 1 to 5% zinc oxide, and is prepared by mixing hot solutions of barium sulphide and zinc sulphate. The precipitate is filtered, dried with great heat, then placed in water and ground to a pulp, after which it is filtered, dried and packed. BISMUTH. The demand for bismuth, owing to its limited use, did not increase to any great extent during the war. For the past several years there have been only two producers of bismuth in this country: the United Metals Refining Company at Grasseli, Indiana, and the American Smelting and Refining Company at Omaha, Nebraska. The bismuth produced in this country is almost entirely a by-product obtained in the refining of lead bullion. Bolivia has been the Avorld's principal producer, in recent years. The entire consumption in this country is probably somew^hat less than 250 short tons annually. The price for the metal ranges from $3 to $i per pound. The only commercial production recorded in California was from Riverside County in 1904, when 20 tons valued at $2400 were pro- duced. Recovery of bismuth in the electrolytic refining of blister copper has been reported, ranging as high as 27.3 pounds of metallic bismuth per 100 tons of blister copper from some Shasta County ores. Industrial application and uses. Bismuth, because of its low melting point and property of expanding when cooling from a molten state, is used principally in the manufac- ture of alloys. Many of these alloys are distinguished by having exceptionally low melting points. Metals with which it is used to form alloys are copper, tin, lead, and antimony. Such alloys are used in various safety devices such as sprinkling systems for fire protection, safety plugs for boilers, electric fuses, etc., also for solders, all of which uses are based upon the low melting point. Also used for type and bearing metals. Considerable bismuth is used for medicinal purposes, surgical dress- ings, and the oxide and subnitrate are used in porcelain painting and glazing. Properties and ores. Bismuth (Bi) is a silver white metal with a slight reddish tinge. Metallic luster which does not tarnish in dry air, but becomes dull and dark brown in moist air. It is soft (hardness 2.0-2.5), quite heavy (specific gravity 9.70-9.83) and very brittle. When heated in COMMERCIAL MINERALS OF CALIFORNIA. 23 the air it burns with a bluish flame, forming a yellowish oxide. Native bismuth sometimes occurs with its ores and also with the ores of cobalt silver and gold. Bismite (BisOg) Oxide of bismuth. Bismuth ocher. Color gray to yellow. Occurs as soft earthy coatings. Bismiitite (BioCOsHgO) Hydrous carbonate of bismuth. Color white to dirty green. Vitreous to dull luster. Occurs as incrusta- tions and earthy. Bismuthinite (Bi^Sg) Sulphide of bismuth. Bismuth glance. Lead gray color and streak, metallic luster, hardness 2.0, specific gravity C.4-6.5. It is supposed that the bismuth occurring in gold and copper concentrates is in this form. As a distinct mineral has only been noticed in a few localities. Distribution. Native bismuth and the ore bismite have been found in the tour- maline gem district in San Diego and Riverside counties, and several bismuth minerals have been found in small quantities in Inyo, Mono, Fresno. Nevada, San Bernardino and Tuolumne counties. Native bismuth is often found in pegmatitic veins. Tests. Usually bismuth is easily reduced from its compounds by mixing a little of the powdered mineral with 3 volumes of sodium carbonate, and heating on charcoal in the reducing flame of the blowpipe. The globules of the metal thus obtained are bright when hot and dull when cold, brittle and easily fusible. The charcoal is covered with a coating of bismuth oxide which is a lemon to orange yellow color near the assay and white a little distance away. When heated on charcoal in small oxidizing flame with 3 or 4 vol- umes of a mixture of potassium iodide and sulphur, a coating is produced Avhich is yellow near the a^say, and bordered on the outer edge with brilliant red. If the mineral is soluble in hydrochloric acid, evaporate the solution until only a few drops remain and then pour into a test tube about one-third full of water. A white precipitate will form. Metallurgy. The metallurgy of bismuth is similar to that of lead, and as stated above, almost all the bismuth produced in the United States is obtained in the electrolytic refining of lead bullion. The greatest part of the world production comes from Bolivia in the form of crude bullion and is sent to London, England, for refining. The refining of bismuth 24 CALIFORNIA STATE MINING BUREAU. base bullion requires great skill, the value of the refined metal de- pending upon the method and care with which it is refined. There are only a few specialists in this line. BORAX. California is the sole producer of borax in the United States. The existence of deposits in western Nevada has been known for years, and considerable exploration has recently been made, notably at Cave Springs. Production consists principally of the mineral colemanite mined in Inyo and Los Angeles counties. Industrial application and uses. The principal compounds derived from the crude borate minerals are borax and boric acid. Of these two, borax is produced in larger quantities. The greater part consumed in this country is used in the manufacture of enamel or porcelain coatings for cooking utensils, sinks, bathtubs, etc. About one-quarter of the total production of both borax and boric acid is sold through the wholesale and retail druggists, and other dealers for domestic reqairements. About one- third of the combined production is used in the manufacture of other chemicals. The remainder is accounted for in its use among fish and meat packers, tanners and manufacturers of glass, soap and pottery. Properties and ores. Borax is a hydrous borate of sodium (NaoB^O^lOHgO). It is colorless or white, sometimes transparent, dull to greasy luster, very soft (hardness 2.0-2.5) and light (specific gravity 1.7). Has a sweet and alkaline taste. Occurs as a powder, incrustations, or small crj^s- tals. Contains approximately 36.5% B^Og, 16.5% Na20 and 47% H,0. Colemanite is a hydrous borate of calcium (CagBcOn SHoO). Color- less, Avhite, or yellow white, vitreous luster, hardness 4.0-4.5, specific gravity 2.4. Occurs in beds, interstratified with lake sediments, as clays, sandstones and conglomerates. Contains approximately 50% B2O3, 27.5% CaO and 22.5% HoO. Ulexite, called 'cotton balls.' Hydrous borate of sodium and calcium (NaCaBjjOo.SHgO). Color white, silky luster, very soft, and light. Usually in nodules or sheets of fine fibers. Distribution. Borax was first discovered in California in the waters of Tuscan Springs in Tehama County in 1856. Later in the same year Borax COMMERCIAL MINERALS OF CAUFORNIA. 25 Lake in Lake County was discovered. This latter deposit produced over one million pounds of refined borax from 1864 to 1868. This was the first commercial output in the United States. Production from the dry lake deposits in Inyo and San Bernardino counties began in 1873 and in 1887 the industrj^ was revolutionized by the discovery of colemanite beds at Calico in San Bernardino County, These have since been worked out, and the present production comes from similar beds in Inyo and Los Angeles counties. There are colemanite de- posits in Ventura Count}^ that have not been worked on account of no transportation facilities. The natural borax is usually accompanied by sulphates of lime and soda and is common at many depressions or sinks in the desert. Tests. Easily distinguished by its physical properties and taste. "When heated it fuses easily with much swelling and imparts a yellow color to the flame. It is readily soluble in water and dilute hydrochloric acid. Turmeric paper, when moistened with the solution and dried, assumes a reddish-brown color. Most borates impart a green color to the blowpipe flame. Preparation. Colemanite is washed to remove soluble sulphates and chlorides, and then boiled with a slight excess of sodium carbonates. The clear liquid 'is allowed to crystallize, producing a crude borax, containing some Glauber salt (NasSO^.lOIIoO). This is redissolved, heated, a little sodium hypochlorite added, and the liquid run into closed crystallizing tanks, where it cools very slowl}^ When the tempera- ture reaches 33° C. the mother liquid is drawn off, leaving the pure crystallized borax. CADMIUM. Cadmium was first produced in the United States in 1907 by a single chemical company and the industry has grown until in 1917 there were six producing companies, one of which was located in California. Previous to this production, the greatest output came from the zinc producing regions of Silesia, where it was recovered as a by-product in the distillation of the zinc. In 1907 the domestic production was nearly sufficient to supply tbe home demand, but in the next few years the imports increased. Since 1912, however, the home production has made great strides and in the last four years the imports, which came largely from Germany, have been practically stopped. The domestic supply is derived from plants wliieh treat zinc ores, or lead ores carrying zinc. 26 CALIFORNIA STATE MINING BUREAU. Production was recorded in California for the first time in 1917. This was several thousand pounds of metallic cadmium, but exact figures cannot be given because the output was by a single company. Industrial application and uses. Cadmium is used principally in the so-called cliche alloys. These alloys have an exceedingly low melting point and are said to be supe- rior to those of bismuth. They are used mostly in safety plugs for boilers, electrical apparatus, automatic sprinkler systems, etc. Re- cently it has been used as a substitute for tin in solders. It is believed to have a certain military use in smoke bombs, and small-arms ammunition. Various cadmium salts are used in medicines, dentistry, dyeing, photography and electroplating. Properties and ores. Cadmium is produced in two forms : metallic cadmium and the pigment cadmium sulphide. Metallic cadmium rarely occurs in nature. It is white, lustrous, rather soft, and has a very low melting point, and specific gravity of 8.6. GreenocJcite (CdS), cadmium sulphide is the only cadmium mineral and is very rare. It is lemon or orange yellow in color, resinous or adamantine luster, hardness 3.0-3.5, specific gravity 4.9-5.0. Occurs as thin coatings on sphalerite. Distribution. In California cadmium has been produced at the electrolytic zinc plant of the Mammoth Copper Company, in Shasta County. It occurs associated with the zinc sulphide, sphalerite, probably as greenockite. Occurrences have also been noted in Mono and Riverside counties. Tests. The sulphide greenockite, when heated on charcoal in the reducing;' flame of the blowpipe with a little sodium carbonate, gives a reddish- brown coating of cadmium oxide. To distinguish from zinc, with which it usually occurs, the cadmium coating occurs before that of zinc. Also when treated with warm hydrochloric acid, hydrogen sulphide gas is given off which may be distinguished by its odor. CEMENT AND LIME. Cement is one of the most valuable mineral products of the state, ranking fourth in value in 1918. The recent increased demand for this material in many branches of the great war construction program COMMERCIAL MINERALS OF CALIFORNIA. 27 has been greatl}' felt in California, as well as in the other producing states. Portland cement was first produced commercially in California in 1891. and the industry has advanced in rapid strides since then. Industrial application and uses. Cement is one of the most important structural materials. In con- crete and reinforced concrete buildings, bridges, docks and structures of all kinds, concrete road-beds, pavements, water pipes, sewers, etc., enormous quantities are used. Under war conditions structural steel is expensive, difficult to obtain and greatly needed for military pur- poses, and every effort has been made to substitute reinforced concrete wherever possible. The construction of concrete ships which has re- cently become a great success, and other industries which this will liO doubt lead to, will call for a considerable increase in the output of cement. Lime is most commonly used in the form of 'slaked lime' in mortar and whitewash. It is also used in making bleaching powder, calcium carbide, sodium hydroxide, in glass manufacture, to remove hair from hides, in dyeing and bleaching cloth, and as a disinfectant. Limestone is used as a smelter flux, as a purifier in the sugar industr^^, as a fertilizer, for various roofing preparations, paints, etc., and for making carbon dioxide. Properties and ores. Limestone (CaCOg), calcium carbonate, in its many varieties, is one of the most common minerals, and vast deposits are found in many states. The common varieties, having the same composition, are ealcite, marble, Iceland spar, onyx, chalk, coral, stalactites, stalag- mites, travertine, etc. The large deposits are massive or granular, while perfect rhombohedral crystals of ealcite are very common. The color is white, yellow, brown, pink, or bluish; vitreous luster; soft (hardness 3.0); specific gravity 2.7; perfect cleavage. Lime (CaO), calcium oxide is a hard white solid, formed by heating limestone in partly closed containers. When exposed to the air it becomes 'air slaked,' i.e., absorbs water and carbon dioxide, swells and crumbles to a powder. It combines actively wuth water, giving off considerable heat, as may be seen in the preparation of mortar. The product is called 'slaked lime.' Pure lime is almost infusible, and when heated intensely gives off a brilliant white light. Cement is made by heating to an incipient fusion a mixture of lime- stone and clay and grinding the clinker product to a fine powder. It must meet certain standard specifications such as fineness, specific 28 CALIFORNIA STATE MINING BUREAU. gravity, loss on ignition, etc., and when mixed with water must develop a required tensile strength when it 'sets.' When mixed with sand, gravel, or crushed rock and water, the product is concrete, and when reinforced with steel rods or bars, it becomes reinforced concrete. , Distribution. In San Bernardino County there were three operating cement plants in 1918. The following counties each have one plant in operation: Contra Costa, Kern, Napa, Riverside, Santa Cruz and Solano. Lime was produced principally in Santa Cruz and San Bernardino counties. Pennsylvania is the largest cement producer, followed by Indiana, New York, California, Missouri, Michigan, Kansas and Iowa. Tests. Fragments of caleite, or limestone, when treated with cold dilute hydrochloric acid effervesce freely. If a small amount of the powdered mineral is dissolved in a very small quantity of hydrochloric acid and then dilute sulphuric acid added, a white precipitate of calcium sulphate will be formed. CHALK. Chalk is a v^ariety of limestone, made up of small and generally broken or powdered shells of marine mollusks, a large proportion of which are microscopic forms called foraminifera. It is white, very light and loosely coherent in structure. It is quite common in parts of Europe and the most noteworthy deposits are in the high cliffs along the English coast near Dover. True chalk was not» found in the United States until recent years. The material used was imported from Hull, England. Deposits of considerable extent are now known to exist in Arkansas, Kansas, New Mexico and Texas, and some commercial production has been made. No deposits have been found in California, but the limestone produced in this state is used for purposes similar to those for which chalk is utilized. (See Lime and Cement.) Infusorial and diatomaceous earth are chalk-like materials, but are composed of pure silica, and are sometimes incorrectly spoken of as chalk. These materials are described under that heading. CHROMIUM. The war demand for chrome ore increased activities in this branch of the mining industry to an enormous extent. California is by far the greatest producer in the United States — in fact, before 1916 it was for many years the sole producer, and the great increase in the COMMERCIAL MINERALS OF CALIFORNIA. 29 domestic supply after the United States entered the war was due almost entirely to the increased output in California. Owing to the fact that the characteristic occurrence of high grade chromite is in the form of comparatively small kidney-shaped masses in serpentine, it is difficult to make an estimate of the amount of ore in a deposit, and ore-bodies cannot be blocked out and future operations calculated as in the case of other important minerals. Industrial application and uses. Chromite is used most extensively as a refractory-lining in furnaces for smelting steel and copper. Large amounts also are used in making chrome-steel alloys, which go into the manufacture of armor plate, projectiles, aeroplane motors, automobiles, etc. Chemicals for dyes, paints and leather tanning are also made from this ore. Properties and ores. Chromium never occurs free in nature. Its chief ore is the oxide called chromite, or chrome iron (FeCrgO^). It is iron black in color, powders brown, has a brown streak and sub-metallic luster. Breaks with a rough unpolished surface. It is very heavy (specific gravity -4.5) and quite hard and tough. Usually found in masses in green serpentine, or along the contacts betw^een serpentine and slate or other similar rocks. It is one of the primary minerals in deep-seated igneous rocks, rich in iron and magnesia, sucli as peridotite and p}'- roxenite. The associated minerals, olivine and pyroxene, are altered to serpentine, so that it is recognized as the enclosing rock of mast bodies of chromite. Distribution. Information gathered by the Mining Bureau shows there is quite a distinct belt of deposits extending along the foothills of the Sierra Nevada from the vicinity of Quincy, southerly, through the central portion of Nevada and Placer counties, and the western portion of El Dorado, Amador, Calaveras and Tuolumne counties. There have been no deposits reported from Madera County, but there seems to be an extension of the above belt through Fresno County a few miles east of Fresno, and through Tulare County from Visalia southerly to the vicinity of Porterville. There is a belt of scattered deposits in the Coast Range in Napa, Sonoma, Lake and Mendocino counties. Quite a distinct belt extends nort"herly and southerly through the central easterly portion of Butte County. In the north a belt extends through the central portion of 30 C^VLIFORNIA STATE MINING BUREAU. Siskiyou County, southerly into the northwesterly portion of Shasta County. There are many other deposits, notabl}^ in Del Norte, Te- hama, Glenn, Alameda, Inyo, San Luis Obispo, Santa Clara, and Stanislaus counties. Test. An easy test for this mineral may be. made with the borax bead, or soda phosphate bead, made by dipping a small loop of fine platinum wire in borax or soda phosphate, and heating until reduced to a clear glass. A very small portion, or a little of the powder of the mineral containing chromium, will color this bead a beautiful green. Metallurgy. Chromite containing around 40% CrgOg is made into bricks slightly larger than the ordinary building bricks and used directly as a re- fractory lining. Ferro-Chromium, used in the manufacture of steel, is made in the electric furnace. The finely ground chromite is mixed with coal and shoveled into the furnace around the electrodes. Reduction takes place and the alloy is tapped from the bottom of the furnace into iron receivers. The charging is continuous so that the top of the mix remains unfused. The alloy contains from 60 to 65% chromium and from 5 to 9% carbon. For the higher grade ferro-chromiums, a subsequent refining is necessary. The physical properties depend upon the amount of car- bon present. When containing 5% or more carbon, the alloy is iron gray in color, when containing 2.5% carbon it resembles aluminum, and with 0.5% carbon it is much like pure lead. Chromite containing about 50% Cr203 is the ore generally used for the production of ferro-chromium. Low grade ores have been successfully concentrated by both the ordinary wet and dry methods of concentration. The chromium steels contain from 0.5% to 4% chromium, and from 0.2% to slightly over 1% carbon. Armor plate steel contains about 1.5% chromium, 3.25% nickel and 0.25% carbon. In the manufacture of steel, chromium does not remove impurities as to titanium, manganese and silicon. In small amounts, it increased the tensil strength and hardness without decreasing its ductility, but in large amounts it causes brittleness. COMMERCIAL MINERALS OF CAIJFORNIA. 31 CLAY, POTTERY, BRICK AND TILE. Ohio has for many years been the leading state in the value of clay products, followed by Pennsylvania, New Jersey and Illinois. Industrial application and uses. Common brick has for years been one of California's principal pro- ducts and is extensively used in building construction. Building tile is also largely used in many kinds of structural work. Clay when made into pottery is used for sewer pipe, chimney pipe, architectural terra cotta, ornamental tiling, porcelain, sanitary ware, stoneware, flower pots, etc. Sewer pipe is the most valuable product, with architectural terra cotta and sanitary ware ranking next. Properties. The clays, in general, are aggregates of hydrous and anhydrous aluminous silicates, free silica and varying quantities of iron oxides, with calcium and magnesian carbonates. They are of secondary origin, resulting from the decomposition of various rocks and minerals, and the accumulation of their less soluble residues. Most of the common clay or kaolin results from the decomposition of feldspar. The most striking characteristics of clays are their plasticity, i. e., easily molded into various shapes, and their induration, i. e., become hard and resistant upon heating. They are moistened with water and molded into various shapes by hand on the potters wheel, or shaped by molds or presses. When dried and burned in a kiln they become Arm and hard like stone, entirely lose their plastic property and are very resistant to the action of water, air and heat. In color they may be white, yellow, brown, blue or red. Distribution. • Pottery clay is very widely distributed in California, having been produced at various times in thirty-three counties. In 1917 the largest producing counties were, in order. Riverside, Amador, Placer, Los Angeles, Alameda, and Santa Clara. There are many large pot- tery works which produce a great variety of products, including many architectural and ornamental shapes. In the manufacture of brick, Los Angeles County leads all others by a large margin, followed by Alameda, Contra Costa and Riverside counties. Tests. To be of the most commercial value, clay should be extremely plastic, should be free from coarse sand or other coarse material and should be low in iron if a ligrht colored ware is desired. 32 CALIFORNIA STATE MINING BUREAU. COAL. As early as 1860 coal was produced in California and in 1861 there was a reported production of 6,620 short tons. During the next forty odd years there were several coal mines of considerable size in operation^ which contributed substantial!}^ to the fuel of the state, the production reaching a maximum in 1880 of 236,950 short tons. Of more recent years the greatest production of record was in 1900 when 176,956 tons were produced, valued at $535,531. The development of the petroleum industry in California has forced coal into the background. Since 1903, the production has rapidly fallen off and now the coal mines, with a few exceptions, are practi- cally abandoned. q Properties. In general, the California coal as mined, is of an inferior quality, being soft, friable and lignitic. It disintegrates soon after mining and will not stand much handling. This has made it difficult for producers to compete with coal of better quality from outside sources. Distribution. The principal coal producing districts in California have been as follows; north of Mount Diablo in Contra Costa County; at Corral Hollow near Tesla, several miles to the southeast in Alameda County; Stone Canyon in Monterey County ; and near lone in Amador County. In the district north of Mount Diablo there are two principal beds, each having a thickness of about three feet, with other small beds, only a few inches in thickness. Although the district is much faulted, coal outcrops can be traced on the surface for several miles. These deposits were first worked in 1861. They belong to the Upper Cret- aceous or Lower Eocene period and occur ifi light colored sandstones and associated shales. The deposits at Corral Hollow or Tesla, in Alameda County, are along the same general strike and of the same geological period as those north of Mount Diablo. The beds are narrow and much faulted. They were discovered in 1870 and are said to be not yet worked out. Deposits in the Stone Canyon district were discovered in 1870, but were not worked until 1908. These mines are located on the west side of the Mount Diablo range, twenty-three miles northeast of Bradley, Monterey County. The coal bed has a uniform thickness of about fifteen feet, and is said to extend for eight miles. The coal is bitu- minous and of a better quality than that from the other districts. The production is reported to have been in the neighborhood of 27,000 tons in 1909. COMMERCIAL MINERALS OF CALIFORNIA. 33 111 the lone district, Amador County, thirty-six miles southeast of Sacramento, the coal beds vary from five to fifteen feet in thickness. They are lignite, near the surface and easily worked. The district has been a- small but continuous producer since 1877 and the coal has found a ready local market. In Rivei-side County, six miles east of Elsinore, coal has been mined from a small deposit for a number of years. It is lignite, and is used locally for heating purposes. Other workable deposits are known to exist in Fresno, Mendocino, Shasta, Siskiyou and San Benito counties. The Beckman-Linden Engineering Corporation, 593 Market street, San Francisco, in June, 1919, purchased the Tesla property and com- menced the erection of buildings and the installation of machinery and equipment for mining and grinding the coal. The powdered product will be used at the property for the generation of electric power. It will be fed into the fire boxes of boilers by air blasts, similar to the way in which crude oil is used. This method has proved highly satisfactory in other localities. Extensive operations are planned so that the near future will no doubt witness the return of the old time activities in this district. COPPER. Copper has for several years been one of the three principal mineral products of the state, being exceeded in value only by petroleum and gold. It is one of the stable mineral products of the United States, rank- ing next to iron in usefulness. The main producing states are Ari- zona, Michigan, Utah, California, Montana and Colorado. Its many and varied uses have constantly increased the demand for this metal. Industrial application and uses. Probably the greatest single use for copper is in making wire, used for telegraph and telephone lines, electric railway and lighting systems, cables, and electrical apparatus in general. In the form of sheets, foil, bars, wire, bolts, rivets, washers, etc., it has innumerable uses in almost every manufacturing industry. Many household articles, cook- ing utensils, boilers, etc., are made of copper. All nations use it as the chief ingredient of small coins. Copper plates are used for en- graving and printing. Many alloys are composed mainly of this metal, brass containing from 63 to 72%, the remainder being zinc. Brass is harder than copper and has many uses for which the latter is not suited. Bronze contains from 70 to 95% of copper. Other alloys are gun metal, bell metal and so-called German silver. 3-24W 34 CALIFORNIA STATE MINING BUREAU. Properties and ores. Native copper (Cu) has the well known copper-red color, metallic luster, is malleable and ductile, soft (hardness 2.5-3.0) and heavy (specific gravity 8.83). Found in irregular masses, wires or thin sheets, cr.ystals are rare. Ores are chalcocite, ehalcopyrite, bornite, tetrahedrite, cuprite, malachite and azurite. Chalcocite (CugS) Copper sulphide. Copper glance. Dark lead-gray to black in color, black streak, metallic luster, hardness 2.5-3.0, spec- ific gravity 5.7. Generally occurs massive. Contains 79.8% copper and 20.2% sulphur. Chalcopyrite (CuFeS) Copper and iron sulphide. Copper pyrites. Color deep brass yellow, often with iridescent tarnish, streak greenish black, metallic luster, hardness 3.5-4.0, specific gravity 4.1-4.3. Gen- erally ma^ssive. Contains 34.6% copper, 30.5% iron and 34.9% sulphur. Bornite (CUgFeSg) Copper and iron sulphide. Peacock ore. Color reddish-brown, tarnished to peacock colors, grayish-black streak, metal- lic luster, hardness 3.0, specific gravity 4.9-5.4. Generally massive. Contains 55.58% copper, 16.36% iron and 28.6%o sulphur. Cuprite {Qu^O) Red oxide of copper. Color red, streak brownish- red, submetallic to adamantine luster, hardness 3.5-4.0, specific gravity 5.99. Occurs massive and contains 88.8% copper and 11.2% oxygen. Tetrahedrite (CugSbgSj) Sulphantimonite of copper. Gray copper. Color dark steel gray, streak black, brown, to cherry-red, metallic lus- ter, hardness 3.0-4.5, specific gravity 4.4r-5.1. Occurs massive and often contains iron, zinc, silver, mercurj^ and arsenic. Malachite (CuCOsCuOH) Basic carbonate of copper. Color and streak light green, vitreous luster, hardness 3.5-4.0, specific gravity 4.0. Structure fibrous, stalactitic, botryoidal or radiating tufts. Azurite (2CuCOoCu(OH)2) Color deep azure blue, streak light blue, vitreous to adamantine luster, hardness 3.5-4.0, specific gravity 3.77-3.83, occurs massive, earthy or in good crystal aggregates. * Distribution. By far the greatest production in California comes from Shasta County. In 1918 it produced 25,294,590 pounds, valued at $6,247,764. Production was reported from 25 other counties, the principal ones being, in order, Plumas, Calaveras, San Bernardino, Placer, Siskiyou, Inyo and Madera. Tests. Copper minerals when moistened with hydrochloric acid and heated give a strong azure-blue color to the flame, which is usually tinged on COMMERCIAL MINERALS OF CALIFORNIA. 35 • the edges with emerald green, characteristic of copper oxide. The dilute nitric acid solution is rendered blue by the addition of ammonia in excess. When fused before the blowpipe on charcoal with a flux of equal parts of sodium carbonate and borax, metallic globules of copper are obtained. ' Metallurgy. Copper ores are smelted in both blast and reverberatory furnaces. Iron oxide, limestone and silica are used as fluxes and coke is the fuel commonly used in blast furnaces, while various cheaper fuels may be used in reverberatory furnaces. In the blast furnace the charge is introduced through a door at the top and consists of alternate layers of coke and ore, the latter being mixed with fluxing materials. The proper proportion of fluxing materials is calculated from the composition of the particular ore to be treated. Combustion is maintained by blasts of hot air through openings, called 'tuyeres' near the bottom of the furnace. As the charge is melted to a fluid condition, the metals settle to the bottom of the furnace and are drawn off in the form of 'matte.' This is a mixture of sulphides, principally copper and iron, and generally contains gold and silver values. The fluxes combined with tlie gangue minerals to form 'slag' which remains above the 'matte,' and is drawn off at intervals. The process is a continuous one. new charges being added at regular intervals. In some sulphide ores containing a high percentage of sulphur a preliminary roasting process is necessary to eliminate some of the sulphur. In the reverberatory furnace the fire box is separated from the charge by a low partition and the heat is carried directly over the surface of the mixed ore and flux by a draught. This furnace is particularly adapted for smelting fine ore and is used in localities where fuel is cheap. The capacity is not usually as great as that of the blast furnace and the removal of the 'matte' and 'slag' and recharging operations necessitate delays. The molten 'matte' resulting from either of the above smelting methods, is drawn off into steel ladels and transferred, generally by means of electric cranes to the converters. These converters are steel, bowl shape vessels from ten to twenty feet in diameter and mounted so that they may be tipped to receive the 'matte' or to discharge the finished product. By means of air blasts, through 'tuyers' at the bottom of the converters, the charge of 'matte' is oxidized to 'blister copper' which contains about 75% copper. Blister copper may also be produced from the matte by a series of roasting operations in reverberator}^ furnaces. 36 CALIFORNIA STATE MINING BUREAU. The 'blister copper' is finally refined to pure metallic copper, the most modern method being by electroysis. A preliminary refining treatment is often given the 'blister' in a reverberatory refining furnace. In the final electrolytic refining operation the associated gold, silver, platinum and other precious and rare metals are recovered. In elec- trolytic refining the blister copper is first melted and cast into anodes. B}^ electrolysis, cathode copper 99.98% pure is deposited. These cathodes are melted and cast into the various commercial shapes. The wet method of treating or leaching is used on carbonate or oxidized copper ores. The leaching solution is generally dilute sul- phuric acid and the copper is precipitated electrolytically as cathode copper or as cement copper, precipitated on scrap iron. Many low grade copper sulphide ores are now being concentrated by means of oil flotation. CORUNDUM AND EMERY. The demand for corundum and emery has increased considerably in the last few years in the United States, due to its use in grinding and polishing metals used in the war industries and due to decreased importation from foreign countries. . The imports which come principally from Turkey and Greece, have decreased steadily in the last several years owing to the war's inter- ference in mining and shipping. There has, as yet, been no production in California. Industrial application and uses. Most of the corundum and emery is used for abrasive purposes: in emery wheels, emery powder or emery paper, etc., for polishing and grinding steel and glass. In this regard it is used in many of the war industries and in the manufacture of munitions. Properties and ores. Cormidum (Al.Og) oxide of aluminum. Color generally bluish gray; also blue, green, yellow or red; vitreous luster; exceedingly hard (hardness 9.0) ; specific gravity 3.9-4.1. Often occurs in crys- tals quite pure which are familiarly known as ruby and sapphire. Corundum often occurs in nature, mechanically mixed with a large proportion of magnetite and this material is the emery of commerce. It is a massive, dark gray or black material, nearly opaque, hardness 8.0, specific gravity 4.0, more or less magnetic. Both corundum and emery are generally found in the older crys- talline rocks. COMMERCIAL MINERALS OF CALIFORNIA. fii Distribution. Corundum has been produced in the United States only in North Carolina and Georgia, and in 1917 the production came entirely from the former state. There are undeveloped deposits in other of the Appalachian states and in Montana. Production of emery has been from New York and Virginia. There are deposits in Massachusetts, but there was no production from there in 1917. No commercial production has been made in California. Good crystals of ruby and sapphire have been found. Tests. Distinguished by extreme hardness. The finely pulverized mineral when made into a paste with cobalt nitrate and intensely heated before the blowpipe on charcoal assumes a blue color, due to aluminum. DOLOMITE. The use of dolomite as a refractory in the steel industry, and as a flux in smelting other metals has increased the demand for this material. Industrial application and uses. Most of the dolomite is used as a refractory lining in open-hearth steel furnaces, thus acting as a substitute for magnesite. It is also used in the manufacture of carbonic acid gas (CO2) and magnesia, and as a flux in the smelting of some of the metals. Recently, the calcined product has been used in the manufacture of paper from wood pulp. Properties and ores. Dolomite (CaMgCOs) calcium magnesium carbonate, may be regarded as an intermediate between calcite or limestone (CaCO.,) and magnesite (MgCOg). It is white, gray, brown or pink in color, vitreous to pearly luster, perfect rhombohedral cleavage, hardness 3.5^.0, specific gravity 2.88. Occurs massive or as rhombohedral crystals wifh curved faces. Much of the limestone in California is magnesian bearing or dolomitic, and it is difficult to distinguish be- tween these minerals and dolomite. It is commonly associated with magnesian silicates, especially the serpentine rocks, in which it is often found as white veins. It may be calcined or burned like limestone. Distribution. Dolomite is a very common mineral, but not so abundant as calcite. The commercial production comes from quarries in Inyo, San Benito, 38 CALIFORNIA STATE MINING BUREAU. San Bernardino, Monterey and Tuolumne counties. Occurrences have been noted in Calaveras, Nevada and Santa Clara counties. Tests. Fragments effervesce freel}^ in hot, but not in cold dilute hydro- cWoric acid (HCl). This hydrochloric acid solution when sufficiently concentrated gives with dilute sulphuric acid (H2SO4) a precipitate of calcium sulphate. To test for magnesium disolve a very small portion of the mineral in a little hot hydrochloric acid, add a few drops of nitric acid to oxidize the iron which may be present, add water, heat to boiling and add ammonia in excess. Filter off precipitate, if any has been found, add ammonium carbonate or oxalate, filter off the precipitated calcium and then test for a precipitate of magnesium by adding sodium phos- phate. FELDSPAR. California and the Atlantic seaboard states are the only commercial producers of feldspar in the United States. The industry is a com- paratively new one in this state, the first production noted l^eiug in 1910. Industrial application and uses. Feldspar is used principally in tlie manufacture of pottery, china- ware, porcelain, enamel ware, enamel brick, tile, etc. It is used in both the body and the glaze of pottery products, constituting from 10 to 35% in the body, and from 30 to 50% in the glaze or enamel. Its value in the body of pottery lies in the fact that it melts during firing at a lower temperature than the other ingredients and forms a firm bond between the particles of clay and quartz. The newest use to which feldspar is now being put is its introduc- tion into the raw mix in cement plants. The silica enters into the cement reaction, and the potash is recovered in the fine dust as a by- product. The notable increase in the California output for 1917, was due to this use by the cement companies, and particularly by the Riverside Portland Cement Company. Since it possesses the qualities of both a binder and an abrasive material, feldspar is quite extensively used in the manufacture of scouring soaps of many kinds, emery, corundum, glass, poultry grit, roofing material, and for surfacing concrete work. Feldspar as a fertilizer is of value only under special conditions, and attempts to extract the potash content are still in the experimental stage. COMMERCIAL MINERALS OF CALIFORNIA. 39 Properties and ores. The common feldspars are composed of silica, alumina, and one or more of the bases — potash, soda and lime. Orthoclase and microcline (KAlSigOg) are potash feldspars, while albite (NaAlSigOg) is the soda feldspar, and anorthite (CaAlgSiaOg) is the lime feldspar. The great majority of feldspars are either mixtures of the first two with, usually an excess of potash, in which case they are termed 'Alkalic' feldspar, or of the latter two, in which case they are called plagioclase feldspar. All grades of plagioclase are found with compositions varying from pure albite to pure anorthite. One of the most important is labradorite, in which there are about equal amounts of the two kinds. The most valuable commercial varieties are the pure, or nearly pure, potash or soda feldspars, because of the fact that within a certain range of temperature they melt without becoming fluid, and upon cool- ing form strong and colorless or light colored glass. The feldspars are alike in general properties. The cleavage is dis- tinct in two directions at right angles or nearly so, and not so per- fect in a third direction. The cleavages are readily seen by reflected light. The color varies from the pure white, colorless or porcelain- like appearance of the plagioclase, to the flesh color, pink or red, of the orthoclase. The luster is vitreous, sometimes pearly, specific gravity 2.55-2.76, very hard, scratches glass, hardness 6.0-7.0. The requirements for pottery use are that the free quartz should, for best results, be under 5% and in no case over 20%, the iron-bearing minerals such as black mica, hornblende, etc., should be nearly absent. Distribution. The feldspar group is the most abundant and most important of the rock-forming silicates. The development of a deposit upon a com- mercial basis depends upon the quantity, quality, distance from trans- portation, location near manufacturing centers, etc. During 1917 and 1918 production was recorded from Kern, Mon- terey, Riverside, San Bernardino, San Diego and Tulare counties. Tests. The feldspars are distinguished by the two good cleavages, hardness, color and difficult fusibility. They give the characteristic yellow flame tests for sodium, and less readily, the pale violet for potassium. To test for potassium and sodium the powdered mineral is mixed with an equal volume of powdered gypsum and a little of this is inserted 40 CALIFORNIA STATE MINING BUREAU. on a clean platinum wire into the hottest part of the Bunsen burner flame. To observe the violet color of potassium a blue glass is used to absorb the yellow of the sodium. FLUORSPAR AND CRYOLITE. Fluorspar is one of the non-metallic minerals of moderately small value, for which the demand greatly increased during the war because of its use in the manufacture of steel. Early in 1917, after the steel companies liad contracted for their supply at $7 per ton, material for prompt shipment was scarce and the price rose to $21.50 per ton. The average price for the whole year was $10.45 per ton. Early in 1918 prices were $38 to $40 per ton. Principal production was reported from five states: Illinois, Ken- tucky, Colorado, New Hampshire and Arizona. The largest producing district in the United States, if not in the world, is in the adjoining portions of southern Illinois and western Kentucky. No cryolite is produced in the United States, the entire supply used in this country being imported from Greenland. About 4000 tons are imported annually and the average price in 1916 was approximately $42.84 per ton. It is imported free of duty. Industrial application and uses. Fluorspar is used as a flux in the open hearth steel furnaces, iron blast furnaces, founderies, and in gold, silver, copper and lead smelt- ers; in the manufacture of glass, pottery, sanitary enamel ware, and hydrofluoric acid; in the electrolytic refining of lead and antimony, and in the extraction of aluminum from ores. It is also used to some extent for glasses in optical instruments, as a binder in making emery wheels, and carbon electrodes, in the recovery of potash from feldspar, and in Portland cement plants, it is used as a flux to break up the silicates. Cryolite was formerly used to produce sodium salts and alum, but cheaper sources of these materials are now utilized. The more import- ant uses at present are in the manufacture of opaque white glass, for enameling iron ware, in the manufacture of aluminum, and as a flux in the manufacture of Portland cement. Properties and ores. Fluorite (CaFg) Fluoride of calcium, commonly called fluorspar. Colorless, white, green, ^. iolet, blue or yellow, vitreous luster, hardness 4.0, specific gravity 3,2, perfect octohedral cleavage. Usually occurs in cubes, also massive, granular or compact. Found in gneiss, schists^ limestones and sandstones. COMMERCIAL MINERALS OP CALIFORNIA. 41 Cryolite (NagAlFp,) althougli not yet produced anywhere in the United States, should be mentioned along with fluorspar because it is the only other important fluoride and its uses are similar to those of fluorspar. It is snow white to brownish or reddish in color, vitreous or greasy luster, quite soft (hardness 2.5) specific gravity 2.97. Found associated with porphyritic granite, the sulphides sphalerite, galena, chalcopyrite and with siderite. Distribution. Fluorspar is a common mineral, especially with galena in lead dis- tricts, sometimes forming thick veins of commercial value. Deposits have been reported in California from Los Angeles, Mono, San Bernar- dino and Riverside counties, and in 1917 production was made for the first time, from one property in Riverside County. Recently, a deposit is being developed near Yermo, San Bernardino County. Tests. Many varieties of fluorspar when gently heated in the dark, phos- plioresce beautifully, i. e., become luminous and give off purple and green light. It gives the yellowish red flame-test for calcium. It is brittle and when strongly heated decrepitates — flies to pieces. When finely powdered and mixed with an equal volume of powdered glass and 2 or 3 volumes of potassium bi-sulphate and heated in the closed tube, the glass tube is etched and a white ring of silica is deposited. This last test may also be used for cryolite. FULLER'S EARTH. In 1917 the United States produced about 82% of all the fuller's earth w^hich it consumed. It is estimated that the total domestic pro- duction was about 75,000 short tons. The imports during the same year were nearly 17,000 short tons, practically all of which came from England. The average yearly production before 1914 was about 35,000 short tons. The greatest production is from Forida and Georgia, while smaller quantities are produced in Arkansas, California, Colorado, Massachu- setts, South Carolina, South Dakota and Texas. In California, pro- duction was first made on a commercial basis in 1899, and since then it lias been quite varied, ranging from a low mark of 50 tons in 1908 to 1344 tons in 1905. Industrial application and uses. The principal use for fuller's earth is in filtering, purifying, de- colorizing and deodorizing mineral and vegetable oils, also animal fats and greases, lard, cottolene, etc. It derived its name from its early 42 CALIFORNIA STATE MINING BUREAU. use by fullers in removing grease from cloth or wool. Very little is at present used for this purpose. It is used to some extent in the manufacture of pigments for printing wall paper, to detect coloring matter in food products, and as a substitute for talcum powder. Properties and ores. Fuller's earth is a soft, friable, earthy, clay-like material, gray, brown or greenish in color, with dull or slightly greasy luster. It is not plastic and has no definite mineral composition, although in general it may be said to have the composition of the clays, which are hydrous aluminum silicates, and generally contain iron, magne- sium, calcium, etc. It varies considerably in quality and its value depends upon its texture, i. e., its filtering and absorbent properties Distribution. In California, the principal production in 1918 came from Calaveras and Solano counties. There is a large deposit near Elsinore in River- side County. It has also been found in Monterey, Kings and Fresno counties. It occurs in sedimentary beds or may be derived from the weathering of basic ferro-magnesian igneous rocks. , Tests. There are no specific tests for this material. The characteristic appearance, physical properties, and the fact that it is non-plastic j will aid in its detection, and as mentioned above, its valiie must be determined by its quality. ^ GEMS. The value of the gem production in California has decreased greatly in the last few years; since 1910, in which year the total production was valued at $237,475, it has dropped, often abruptly, until in 1917 it was $3049, and in 1918, $650. This is the value of the rough, uncut material. The California production includes diamonds, beach stones, chalcedony, beryl, tourmaline, kunzite, benitoite, topaz and quartz crystals of rare color. Beryl, tourmaline and quartz were the most valuable products in 1917. The total value of the precious stones produced in the United States in 1917 was $131,012. Of this production corundum with its varieties wa*s the largest single item followed in order by quartz, turquoise and tourmaline. These four made up about 83% of the total. Montana leads the states in value of production, with Nevada second, and California third. "' COMMERCIAL MINERALS OP CALIFORNIA. 43 The precious stones imported into the United States in 1917 were valued at $34,846,351. This does not include pearls. The value of a gem stone depends principally upon its rarity, beauty, purity and size. Opinions differ widely as to which are the most beautiful stones. The diamond has been regarded as the most valuable of gems, but some rubies, sapphires and emeralds are a great deal more rare and often of greater value. These four are regarded by most everyone as the real precious stones. The popular mind, taste, and fashion may change the standing of gems, and the resulting change in supply and demand changes their price and value. Industrial application and uses. The first and foremost use for gems has always been for personal adornment. The collections of some of the ancient rulers, including the croAvn jewels, were stupendous and their value could hardly be estimated. In watch-making great numbers of small jewels as rubies, sapphires, and garnets are used, and in the cutting of these many bort diamonds are consumed. In diamond drills, black diamonds and others not suitable for gem stones, are used. Distribution. Small diamonds have occasionally been found in the stream gravels of the Sierra Nevada in connection with gold mining, notably at Volcano, Amador County, Placerville and Smith's Flat, El Dorado County; French Corral, Nevada County; Cherokee Flat and Yankee Hill, Butte County; Gopher Hill and upper part of Spanish Creek, Plumas County. The most productive district has been Cherokee Flat. The tourmaline district in San Diego County has become quite famous, on account of the variety and distinctive coloring of this gem. The Pala Chief mine in San Diego County is the only place in the world where the gem kunzite is found, and the Dallas mine in San Benito County is the sole producer of benitoite in the world. Ruby and sapphire have not been found in good crystals in California. Beryl is found in the pegmatitic veins with tourmaline in Riverside and San Diego counties. Properties. Any mineral which is of value because of its particular or excep- tional beauty, durability or rarity may be termed a gem mineral or precious stone. Strictly speaking, however, the really precious stones are the diamond, ruby, sapphire and emerald and occasionally the pearl (animal origin) and the opal. 44 CALIFORNIA STATE MINING BUREAU. Diamond is pure carbon (C) in composition and is the hardest known mineral. It is brittle, perfect octahedral cleavage, colorless to ■ yellow or blue, adamantine luster, specific gravity 3.5. Euhy, sapphire and Oriental emerald are varieties of corundum (AI2O3) oxide of aluminum. Vitreous luster, hardness 9.0, specific gravity 3.9-4.1. Ruby is red and sapphire blue, and emerald green. Emerald is a variety of heryl a silicate of beryllium and aluminum \ (BegAlgSieOis)- Color green, sometimes blue, rose or yellow, vitreous luster, hardness 7.5, specific gravity 2.63-2.8. Tourmaline is a silicate of boron and aluminum with various bases. Bnhellite is a variety. Colors mostly rose red and green, vitreous luster, hardness 7.0-7.5, specific gravity 2.98-3.2. Kunzite is a transparent variety of spodumene, a lithium aluminum silicate, LiAl( 8103)2- Beautiful lilac or amethyst color, hardness 6.5-7.0, specific gravity 3.13-3.2. A comparatively new gem mineral. Benitoite is a new gem mineral discovered in 1907 in San Benito County. It is a silicate of barium and titanium (BaLiSigOg). Beautiful sapphire blue crystals, transparent, vitreous luster, hardness . 6.5, specific gravity 3.65. J Topaz is a silicate of aluminum and fluorine (AlF)2Si04. Chalcedony and Opal are forms of silica (SiOs), the former occur- ring in dense cryptocrystalline masses, never transparent, while the latter is wholly amorphous, somewhat softer and contains varying amounts of water, i. e., is hydrous. Opal has a waxy luster, hardness 5.5-6.5. Varieties of chalcedony are agate, carnelian, onyx, jasper, flint, sardonyx and bloodstone. Varieties of opal are, wood opal, moss opal, hydlite, common opal and precious opal. Most of the beach stones found on the California coast and polished for gems are chalcedony. Tests. The testing of gem stones must be left to those experienced in that art. Many stones may be recognized by their color, crystal form, hardness, structure, 'etc., but their value in regard to purity, flawless- ness, etc., must be finally determined under the microscope. I GOLD. During the period of the war the gold producer faced a peculiar and, at the least, a disheartening and unsatisfactory situation. While practically every mineral activity in the state was stimulated by in- crease in value of product, the gold production was actually retarded, because of no such increase in value (since the value of gold must COMMERCIAL MINERALS OF CALIFORNIA. 45 necessarily remain constant) while there was a considerable increase in practically every operating cost. Early in the war the government realized the necessity of main- taining a large gold reserve as a foundation upon which to place the huge war loans and maintain the credit system of the country. An appeal was sent to the gold producers, urging them as their patriotic duty to maintain their output. Great credit is due to many producers who maintained or even in- creased their output under these unfavorable conditions and without any financial aid, often operating not only without profit, but at a loss. Some of the small producers found it absolutely impossible to operate at all. The folloAving data is taken from the report of Mr. Charles G. Yale, Statistician in charge of the San Francisco office of the United States Geological Survey, Division of Mineral Resources: Of the $16,539,053 production in California in 1918, $8,690,174 was the output of deep mines, w^hile $7,848,879 was derived from placers. The gold dredges produced by far the greatest part of the placer gold. Yuba County ranked first in 1918 with a production of $3,735,440, followed closely by Amador, $3,249,385, and Nevada, $3,070,452. Sacramento was fourth, with a production valued at $1,694,724, and Calaveras fifth, $865,389. The three largest and most important dredging fields in the state are near Oroville, Butte County; Folsom, Sacramento County; and ]^>rarysville, Yuba County. The largest production of record was in 1852, in which year the output was $81,294,700. GRANITE. The output of granite in California has decreased in the last few years due to labor shortages, and the increase in reinforced concrete and tile construction. For several years, 1889 to 1892 inclusive, the annual production in California was valued at more than $1,000,000. Industrial application and uses. Granite is used most extensiveh' as a building stone in modern construction. It is extremely durable and many public structures which are built of the California product, present a beautiful archi- tectural appearance. Among the most important of these are the San Francisco Civic Center and the University of California Buildings, and the San Francisco post office. Granite is also used to a great extent for curbstones and monumental work, and for paving blocks. 46 CALIFORNIA STATE MINING BUREAU. Distribution. Madera County is the largest producer in the state, Fresno and . Placer County ranking next. The granite produced at Raymond, | Madera County, and Rocklin, Placer County, is of exceptional quality, ; and so far as known is unexcelled. Other principal producing counties \ are Plumas, Riverside, San Bernardino, San Diego, Siskiyou and j Tulare. The Fresno County granite is dark in color and is particu- j larly suitable for monumental and decorative purposes. GRAPHITE. Graphite is a mineral product of vital importance in time of war because of its use in the manufacture of crucibles for handling molten metals. For this reason American producers greatly increased their output in 1916, 1917 and 1918. In 1917 the United States produced about one-fourth of all the graphite which it consumed, taking into consideration all grades. The total domestic production in this year was 8558 short tons, 3301 tons i of which was amorphous and the remainder crj'^stalline. | The imports which come mainly from Ceylon, amounted to 42,577 tons in 1917, which w^as practically the same as the 1916 figure. The extent to which the demand for this material has increased in the last few^ years may be judged from the fact that both the annual production and the imports for the last two years were approximately double those of 1914 and 1915. The production in California has been small, due to the impure and low^-grade deposits which cannot com- pete with the high-grade imported variety. Low-grade ores are con- centrated with difficulty. The price for amorphous graphite varies greatly with the quality, and fluctations are also due to the varying amounts of low-grade ore mined. Before 1915 the price ranged from $22 to $30 per ton. In 1916 the average had dropped to about $8 per ton, and in 1917 it was around $12.50 per ton. Industrial application and uses. On account of its infusibility, and resistance to the action of molten metals, the most important use for graphite is in the manufacture of crucibles, retorts, and many other refractories. For this purpose the coarse, flake varieties are alone suited, and this variety commands the highest price. It is largely used as an ingredient of lubricants, which use has increased with the growth of the automobile industry. Considerable amounts are consumed in the manufacture of lead pencils, paints, paper and pasteboard products, and electrical apparatus. It COMMERCIAL MINERALS OF CALIFORNIA. 47 is the most satisfactory material for foundry facings, a low-grade graphite being used. Recently it has proved highly efficient in the making of a preparation to loosen boiler scale, and also in the manu- facture of self-lubricating metals. Properties and ores. Graphite, also called 'black lead' or plumbago, is pure carbon in composition. It occurs in nature in two forms: a crystalline or flake variety, and an amorphous or lump graphite. It is dull black in color perfect basal cleavage, occurs in scales or foliated masses, very soft (hardness 1.0-2.0) and greasy. Quite light (gravity 2.2). Widely distributed as a typical constituent of metamorphic rocks. Often distributed through crystalline limestone in minute flakes, and forms layers of more or less prominence in many schists and gneisses. In mining districts it is often seen in the w^alls of veins mixed with the taleose gouge. Most beds of amorphous graphite are the result of alteration of coal beds by the intrusion of igneous rocks. This amor- phous variety is also made artificially in the electric furnace. Distribution. The amorphous variety comes principally from Colorado, Michigan, Nevada, and Rhode Island; while crystalline graphite is produced in Alabama, New York, Pennsylvania, Montana, and to a small extent, in California. Sonoma County at one time furnished the main production in Cali- fornia, which material was used in the manufacture of paint. Occur- rences have been reported from Calaveras, Tuolumne, Fresno, Imperial, Los Angeles, San Bernardino, San Diego, Siskiyou, Mendocino, Hum- boldt and Del Norte counties. In 1916 t\nd 1917, a small output was made by concentration of a disseminated graphitic schist at a deposit in Los Angeles County, the product being utilized for paint, foundry facings and lubricants. R Tests. Distinguished by its softness and greasy feel. Readily marks paper and soils the fingers. Unaffected hy the blowpipe and acids. Preparation. Graphite is separated from the harder and heavier materials with which it is associated by crushing and washing. The lighter spe- cific gravity causes the graphite to be floated off on the water, while the heavier materials are left behind. Mica cannot be removed in this way, and hence micaceous graphite ores are of less value than others. The separation is sometimes made by simply ])lowing the ground 48 CALIFORNIA STATE MINING BUREAU. material by air currents, the heavier material, or impurities, falling first, and the finer material being carried farther. This method also serves to classify the graphite into different grades of fineness. GYPSUM. The gypsum industry was stimulated only in an indirect way by the war, and the production in the last few years in the United States has increased only slightly over the pre-war figures, but the value increased to a great extent. industrial application and uses. Gypsum is marketed in both the raw and the calcined state. The quantity that is calcined is about four times as great as that sold as the raw material. The greatest use of calcined gypsum, amounting to 1,500,000 tons annually, is in the manufacture of plaster. Outside of the ordinary wall coverings, this is used on masonry surfaces, for decorative mouldings, friezes and panels, in making plaster board and in fire-proof and cold storage construction. Considerable amounts are used in stationery and art work, beds for grinding plate glass, foundry moulds, surgical casts, etc. Raw gypsum, after grinding is used as a retarder in Portland cement, for land plaster or fertilizer, in making paints, chalk and crayons, as a filler in cloth and paper manufacture, and as a flux in blast roasting. Properties and ores. Gypsum is a hydrous sulphate of calcium (CaS042H20). Contains 46.6% SO3, 32.5% CaO and 20.9% H.O. It is clear white, light brown, yellow, or reddish in color, vitreous or satiny luster, very soft, may be scratched by the thumb nail (hardness 1.5) and light (specific grav- ity 2.3). Occurs in broad fiat crystals, nearly transparent, cleavage in three directions, perfect parallel to the broad face ; or as the massive variety which is translucent to opaque and finely granular. Varieties are selenite, satin spar, alabaster and gypsite. Distribution. Gypsum is a very common mineral in the state, but extensive de- posits of a good pure variety are exceptional. The mineral occurs associated with stratified rocks and is easily formed by the action of sulphate waters on limestone, consequently small amounts of the mineral are common in mining regions where sulphides are decom- posing. COMMERCIAL MINERALS OF CALIFORNIA. 49 Larg-er deposits are generally formed by the evaporation of lime sulphate waters, and are often impure due to mixture with other salts, clay and organic matter. During 1917 and 1918 there were producers in Inyo, Riverside and San Bernardino counties. Occurrences have been noted in almost every mountain or foothill county of the state. The state of New York has for many years been the largest producer of raw gypsum, followed closely by Iowa, Michigan and Ohio. Largo quantities are also produced in Texas, Oklahoma, Kansas and Wyoming. Tests. The fine powder in readily soluble in dilute boiling hydrochloric acid, and slightly soluble in hot water; tbis solution, upon the addi- tion of barium chloride gives a white heavy precipitate of barium sulphate. This distinguishes it from other sulphates of the alkaline earths and some heavy metals. If the powdered mineral is fused on platinum wire with a mixture of sodium carbonate and charcoal powder, and then transferred to a moistened silver coin it will give a dark stain of silver sulphide. If heated in a closed tube it will give much Avater. Note extreme softness, scratching by finger nail, and excellent eas}^ cleavage. Preparation. The gypsum is prepared for the market by first crushing and then grinding to a powder. If intended for land plaster it is put into bags or barrels in this state, but if intended for building plaster it is calcined. This is carried on in large retorts or kilns, about eight feet in diameter and capable of holding many barrels at a charge. The powder is heated until all the included water is given off, being stirred continuously. It is then drawn off through openings in the bottom of the kettles. « INFUSORIAL AND DIATOMACEOUS EARTH. Production of infusorial and diatomaceous earth in California has been from three actively operated quarries in Monterey and Santa Barbara counties. The first recorded production was in 1889, when 39 tons were produced. Tlie average price varies greatly from year to year due to fluc- tuations in quality and demand. Tliere has been a noticeable increase in production since 1912. Deposits of note besides those in California are in Maryland, Virginia, New Jersey, Nevada and Maine. 4-2484 50 CALIFORNIA STATE MINING BUREAU. Industrial application and uses. These earths are used commercially, principally as absorbent mate- rials, and in the manufacture of dynamite. They are also used in the manufacture of polishing powders, scouring soaps and some refractory brick. They are non-conductors of heat, and are used as insulators. in steel plants and power houses. Properties. During Tertiary time certain waters of the earth swarmed with diatoms and infusoria, i. e., microscopic forms of plant and animal, life having the power of secreting silica, which forms their shells or' protective coatings. Upon the death of these organisms, the siliceous residue accumulates and forms beds, sometimes up to 50 feet in thick- ness, but of very small proportions when compared with other forma- tions of the earth's crust. In composition these infusorial and diatomaceous earths are pure silica, but most deposits contain small amounts of aluminum and iron oxides, w4th lime, soda and potash. They are soft, porous material, resembling clay or chalk, are white, gray or yellowish in col<)r. with gritty feel. Some idea of the great number of forms which a deposit represents may be gained from the estimate that one cubic inch con- tains 40,000,000 independent shells. Distribution. The most important deposits of record in California are in ^Monterey,. Orange, San Luis Obispo and Santa Barbara counties. In Santa Barbara County the material is diatomaceous and of good quality.. Infusorial earth is also found in Fresno, Kern, Los Angeles, Plumas, San Benito, San Bernardino, San Joaquin, Shasta, Sonoma and Tehama counties. Tests. This material can be distinguished by its appearance and physical properties and its gritty feel. To test for silica, £use with sodium corbonate before the blowpipe, either on the platinum wire or on a clean charcoal surface. A glass will be formed which is soluble in acids and which upon evaporation will give a gelatinous precipitate of silica. IRON. Iron is the most useful of all the metals and is produced in the greatest quantities. It has been known since earliest history, and lias been indispensable to the development of civilization. A period of extreme activity was produced by the war, which resulted in a record output of iron ore, pig iron and steel in 1916 and 1917. COMMERCIAL MINERALS OF CALIFORNIA. 51 The greatest producing area is the Lake Superior district, embracing Minnesota, Michigan, and northern Wisconsin. This region has pro- duced about 85% of the total in the past several years. Minnesota J. induces about 60% of the total, thus furnishing more than all the other states combined. Other large producing states are Alabama, New York, New Jersey, Pennsylvania, Tennessee, Virginia, Georgia, Colorado and Wyoming. In California the production of iron ore in 1918 was 3108 tons, valued at $15,947. Industrial application and uses. The principal products are pig iron and various grades of commer- cial iron and steel. Considerable quantities are used in ferro-alloys such as f erro-manganese, f erro-chrome, f erro-silicon ; also as a fluxing material, and in paint manufacture. Properties and ores. Iron compounds are very abundant, and furnish most of the common coloring material in soils and rocks. Pure or native iron is found in meteorites, and in small grains in some igneous rocks. Of the many iron ores the oxides are the most important in the iron and steel industry. Hematite has always been the principal ore and in the last few years has constituted in the neighborhood of 94% of the iron ore mined. Other ores are limonite and magnetite. The carbonate is insignificant in comparison with the other ores. The sulphides are abundant, but are not of commercial importance as regards the iron content. Native Iron (Fe) is usually massive, iron-gray color and streak, metallic luster, malleable, ductile, magnetic, hardness 4.5, specific gravity 7.5. Hematite (Fe203). Red, brown, steel-gray or black in color, red- dish brown streak, metallic, submetallic or earthy luster, hardness 5.5-6.5, specific gravity 4.9-5.3. Occurs massive, with prominent reniform or kidney-shaped structure and often earthy, granular, crystalline or micaceous. Contains 70% iron and 30% oxygen. The black crystalline masses are found with the crystalline metamorphic .or igneous rocks, while the red earthy masses are sedimentary altera- tions of iron-bearing minerals. The flaky 'specular hematite,' is common in crystalline rocks. Limonite (2Fe203). Color yellow, brown or black, streak yellowish brown, submetallic to dull luster, hardness 5.0-5.5, specific gravity 3.6-4.0. Occurs massive, earthy, fibrous, columnar, botryoidal or 52 CALIFORNIA STATE MINING BUREAU. j stalactitic. One of the most common of the iron minerals. Common alteration product of pyrite and other iron minerals, and with hematite forms the great gossan cappiugs of iron sulphide deposits. Magnetite (Fe304). Magnetic iron. Color iron black, streak black, metallic luster, hardness 5.5-6.5, specific gravity 5.1. Strongly mag- netic. Occurs massive, granular or as octahedral crystals. One of , the most abundant iron minerals and ranks next to hematite as an ore. Occurs in igneous rocks, or metamorphic gneisses and schists, often along the contacts of igneous intrusions. Distribution. There are many deposits of iron ore in California, some of which are of considerable size, but production has been limited on account of the lack of a suitable supply of coking coal. Up to the present, the production has been utilized principally in the manufacture of the ferro-alloys by means of the electric furnace. The Minaret iron, deposit in Madera County, said to be the largest in the state, is com- posed of magnetite and has been estimated to contain at least 30,000,000 tons of iron ore. There are several extensive deposits in Shast;i County. Other deposits of note are in San Bernardino, Riverside and Placer counties. The 1918 production was from San Bernardino and Shasta counties. In addition to the electric smelters of the Noble Electric Steel Com^ pany at Heroult, Shasta County, and the Pacific Electro Metals Com-) pany at Bay Point, Contra Costa County^ both of which manufacture ferro-alloys, there are two blast furnaces now said to be in operation,^ one in Shasta and one in San Bernardino County. Tests. Iron compounds are strongly magnetic after heating, before thd blowpipe in the reducing flame. Magnetite is strongly magnetic before heating, and hematite is often slightly so. Limonite and hematite are often easily distinguished by their color, streak and characteristi structures. Metallurgy. Iron is extracted most easily from the oxide ores. These are crushed and roasted, and then smelted in blast furnaces with coke or coal, and a flux of limestone, feldspar, etc. The carbon reduces the oxide to metallic iron, which collects in molten form at the bottom of the fur- nace, while the flux removes the impurities from the ore and forms a 'slag.' COMMERCIAL MINERALS OP CALIFORNIA. 53 The ore is dumped into the furnace at the top with 50% to 65% of its weight of coke, together with limestone, feldspar or other flux necessary to form a pre-determined slag. Combustion is maintained by the introduction of hot air at 500° to 750° Centigrade, through openings at the bottom called 'tuyeres.' The furnaces are often 100 feet high, and are kept constantly filled with charge. The slag and iron are tapped off at regular intervals, the iron being run into moulds . The 64 CALIFORNIA STATE MINING BUREAU. quotation at San Francisco on June 18, 1918 was $1.25 per pound for 90% MoS,. Production up to the present, has been limited mainly to high grade deposits, but it is hoped that the more stable demand will lead to the concentration of the ores at some of the larger deposits. Industrial application and uses. The importance of molybdenum as a valuable alloy metal appears now to be well established. It is a substitute for tungsten in the manu- facture of steel for certain purposes, and in this regard one ton of molybdenum replaces more than two tons of tungsten. About 15 to 20 tons of metal are used per year in making chemicals. Most of the export goes to our allies for the manufacture of high-speed tool-steel, rifle barrels, propeller shafts, etc. This steel contains from 6 to 10% molybdenum. It is also used with tungsten in making electric light filaments, and electric furnaces. Properties and ores. The commercial ore of molybdenum is molybdenite. Composition (MoSo), 59% molybdenum and 41% sulphur. Light bluish gray in color, streak, or powder, lead gray with greenish cast. Occurs in scales or hexagonal plates, or foliated masses. Perfect basal cleavage. Hardness 1.0-1.5. Gravity 4.7. Crystallizes in the hexagonal system., Thin plates are very flexible, but not elastic. Resembles graphite, but slightly different in color. Some wulfenite (molybdate of lead) has also been sold for the molybdenum oxide it contained. This is a yellow, orange, or bright red mineral with resinous or adamantine luster. Occurs massive or in thin tabular crystals. Hardness 3.0-4.5. Gravity 6.0-7.0. To be- marketable, it must be free from impurities such as copper, tungsten, vanadium, chromium and contain at least 25% of molybdenum oxide. Distribution. The Sulphide, molybdenite, is widely distributed in California," usually as thin flakes and leaves, sometimes large and well formed crystals in quartz and crystalline rocks, and contact metamorphic deposits. It occurs in the gold quartz veins of California. In appear- ance it strongly resembles graphite, but has a lighter bluish lead-gray color. When occurring alone it oxidizes to yellow color, and occa- sionally to peculiar cobalt blue tinge. It has been found in the Mother Lode counties and in Fresno, Inyo, Madera, Mono, Napa, San Diego, Shasta, Tulare and Riverside counties. COMMERCIAL MINERALS OF CALIFORNIA. 65 Tests. If a fragment of molybdenite is heated before the oxidizing flame of the blowpipe, on a flat charcoal surface for some time, there results a short distance awaj^ a coating of molybdic oxide (M0O3), which is pale yellow when hot, almost white when cold and often shows delicate crystals. Still nearer to the mineral the charcoal is covered with a very thin copper colored coating of M0O2 which is seen best when cold. The yellow (M0O3) coating if touched for an instant with the reducing flame assumes a beautiful ultramarine blue color, which is very characteristic. This same yellow coating may be obtained by heating a fragment of molybdenite at a high temperature in an open tube. If a small piece is held before the blowpipe at the tip of the blue flame, a pale yellowish green color is imparted to the flame. To test for wulfenite, put a very small portion of the finely powdered mineral in the test tube, add a small scrap of paper, a few- drops of water, and an equal quantity of concentrated sulphuric acid, and heat until fumes of the acid begin to come off. Allow to become cold and add water a drop at a time. A deep blue color appears which vanishes upon the addition of more water. For success in this test a minute quantity of the powdered mineral should be used. Identification of Molybdenite. By F. C. FuCHS.* A small piece of caustic potash is melted in a fragment of a broken porcelain dish and then a little of the suspected mineral is added. Within five minutes, if the sample is molybdenite, it swells, dissolves rapidly, giving the mass an intense red yellowish color, and not a single speck of the brilliant scaly mineral is to be seen. When cool, if a few cubic centimeters of water be added to the residue of fusion, and afterward some drops of hydrochloric acid, the color begins to change and in spots appear the blue, green, yellow and red. Metallurgy. Considerable difficulty has been experienced in the concentration of molybdenite ore. Until quite recently the world markets have been supplied by cobbing and h^and picking the ore from high grade de- posits. Some wulfenite ore is concentrated as this is amenable to the ordinary jig and table concentrating processes. Within the last few years, concentration of molybdenite ore by flotation, with either water or oil, and by electrositatic processes has been to some extent successful. ♦Taken from issue of June 1, 1918, of Engineering and Mining Journal. 5—2484 66 CALIFORNIA STATE MINING BUREAU. Water flotation depends solely upon the fact that small, dry parti- cles of molybdenite float upon the surface, while the gangue materials easily become wet and sink. When oil is added, the particles of molybdenite become coated with oil much more readily than the gangue particles, and this oil coating materially assists their flotation. In some processes, the area of surface of flotation is increased by the liberation of air or gas bubbles in the liquid, the surface of each bubble acting in the -same way as the surface of the liquid. These bubbles may be produced by violent agitation of the pulp. It has been found by experiments that no general method is appli- cable to all molybdenite ores and each individual ore has its own concentration problems. Molybdenum is also placed on the market in the form of a powder made by heating some form of the oxide with a reducing agent, usually charcoal. The process is carried on in graphite crucibles, and the resulting dark powder, commercial molybdenum, can with care, be made 99% pure. The metal may also be prepared by passing hydrogen over the oxide at a red heat. The preparation of the pure oxide is rather difficult. This is generally done by roasting the sulphide and then leaching with ammo- nium hydroxide. Further complex treatment is required. MONAZITE. This mineral is of importance because it is a source of some of the most important of the so-called 'rare earth' elements. The United States, Brazil and India have produced practically all the monazite consumed, while Russia and Norway furnish small quan-' tities. The production in the United States comes from North and South Carolina. The placer deposits in these states were first worked in 1886, and the maximum production was reached in 1895 when 1,573,000 pounds of monazite sand were produced. Imports from the rich deposits in Brazil lowered domestic production. There has been no production in California. Industrial application and uses. The rare elements cerium, lanthanum, thorium, etc., which are gener- ally associated with each other in the mineral monazite, and a few others are used commercially in the form of their nitrates and oxides only. About their only known use at present is in the manufacture of incandescent gas mantles. COMMERCIAL MINERALS OF CALIFORNIA. 67 The mantle is made of fabric, sueh as cotton, and impregnated with the nitrate, which when dried and ignited becomes the oxide, and is held in the flame by means of fine plaitinum wire. When heated the mantle emits an intense white light. Verj^ small amounts (' used in some searchlights, automobile headlights and flashlight !M»\vders. Properties and ores. ^lonazite in composition is a phosphate of cerium, lanthanum, and didymium (CeLaDi)P04. However, it carries quite a per cent of thorium and is the only mineral found in the United States from which the last named rare metal is derived. Uranium and radium may also be present in minute quantities. The common form of monazite is in minute crystals or granules, disseminated through uneissoid or pegnatitic rocks, and owing to their small size they are generally overlooked. It is only after the inclosing rocks are decom- posvd and naitural concentration of the heavy minerals takes place that the monazite granules are found in the resulting sands. Distribution. Monazite has been detected in California in some of the black sands, jind in the concentrates from some of the mines, but no deposits of commercial size are known. Its presence in black sands has been re- ported from Butte, Del Norte, El Dorado, Humboldt, Placer, Plumas and Yuba counties. In North and South Carolina monazite is obtained by washing the sand and gravel in sluice boxes, in the manner in which placer izold is washed. Tests. Dissolve a very little of the finely powdered mineral by heating in a test tube, Avith a few drops of concentrated sulphuric acid. When cool, dilute with a little water, filter if necessary and then add ammo- nium oxalate, when a precipitate of the rare-earth metals will be formed. NATURAL GAS. Natural gas ranks as one of the state's most important mineral pioducts. Outside of a few wells in Sacramento, San Joaquin and Kings counties which produce gas alone, the production comes mainly from the oil producing counties of the state. Practically every oil well produces some gas, but it is not always possible to profitably market it. 68 CALIFORNIA STATE MINING BUREAU. Recently ^reat advancement has been made in tapping the gas at the wells, and every effort is now being made to conserve the supply. It is believed the figures given are far below the actual production, because of many w^ells at which the slight flow of gas cannot be profitably handled, and is not even taken account of. As in the case of oil, Kern County leads in production of gas, almost one-half of the output in 1918 being accredited to this county alone. Orange County was second. Fresno, Santa Barbara, Ventura and Los Angeles are important producers. A 12-inch pipe line is operated from the Midway field in western Kern County to Los Angeles, a distance of 107 miles. Gas is also supplied to Bakersfield, Taft, Fellows and Maricopa. Gasoline is now being manufactured by at least 50 plants by com- pression of the gas which accompanies the oil. This so-called 'casing- head' gasoline bids fair to become a valuable product. The produc- tion in 1918 from all fields was approximately 21,000,000 gallons. In San Joaquin and Sacramento counties, in and near the cities of Stockton and Sacramento, there are many natural gas wells. These wells produce a good quality of gas, which is mixed with manufactured gas for domestic use. Of the states. West Virginia is the greatest producer of natural gas. In 1916 its production was valued at $47,603,396, while the total for the United States was $120,227,468. Pennsylvania was second, followed by Oklahoma and Ohio. California ranked seventh. Prices vary considerably in the different states. In California the average price per thousand feet is about 5^-8^. NICKEL. Practically no nickel-bearing ores are mined in the United States, the supply for many years having come from Canada in the form of a rich copper-nickel 'matte,'" from which the refined nickel is pro- duced. The increased demand for this metal, due to its use in the manufacture of nickel steel, alloys and small coins, has been easily supplied by Canada, for in the past more was received than was re- quired for domestic use and the balance was exported. The proportion of nickel coming from domestic copper ores in the electrolytic refining process is undetermined, but it is known to be small. Industrial application and uses. The most important use for nickel at present is in the manufacture of nickel steel. This contains about 3.5% nickel and is used for armor plate and machines requiring great strength. I COMMERCIAL MINERALS OF CALIFORNIA. 69 For man}^ years nickel has been used as one in^edient of small coins. Our one cent piece contains about 12% of this metal and the five cent piece about 25%. It is used in plating other metals and alloys, such as iron, zinc and brass, by electrolysis. Much ornamental work and many small useful household articles are nickel-plated. So-called 'nickeloid' is nickel-plated sheet zinc. Reflectors and refrigerator linings are often made of nickel. Properties and ores. Nickel is a pure white metal with bright metallic luster, hard, ductile and tenacious. It takes a brilliant polish and does not tarnish in the air. The principal ores are millerite, pyrrhotite and niccolite. MiUerite (NiS) nickel sulphide. Contains 64.4% nickel and 35.6% sulphur. A valuable ore of nickel. Brass yellow to bronze in color often with iridescent tarnish, greenish black streak, metallic luster, brittle, quite soft (hardness 3.0-3.5) and heavy (gravity 5.6). Gener- ally occurs as coatings. PyrrJwtite (Fe^Sg) iron sulphide. Theoretically contains 60.5% iron and 39.5% sulphur, but it is often a valuable ore of nickel, some- times containing 3 to 5% or more of this metal. Color yellow, bronze to copper red, dark grayish black streak, brittle, hardness 3.5-4.5, gravity 4.5, slightly magnetic, and tarnishes easily. Niccolite (NiAs) Arsenical nickel. Also called copper nickel on account of its color. Contains 44% nickel and 56% arsenic. Pale copper red in color, metallic luster, pale brownish red streak, brittle, hardness 5.0-5.5,, gravity 7.3-7.7. Grenerally occurs massive. Occurrence. Nickel-bearing pyrrhotite occurs in the Friday Copper mine in the Julian District, San Diego County. Some ore was mined in 1915 and 1916, but not yet treated. It is claimed that new discoveries have been made in this county and development started. Pyrrhotite has also been found in Siskiyou and Madera counties. Some millerite has been found in Calaveras, Humboldt, Napa, Placer and Plumas counties, but only in small quantities. It is often associ- ated with copper and cobalt ores. Tests. Nickel is usually detected by the color it imparts to the borax bead. In the oxidizing flame it gives a violet color when hot, changing to reddish brown when cold. Nickel compounds when dissolved in nitric acid (HNO3) give an apple green solution and when ammonia is 70 CALIFORNIA STATE MINING BUREAU. added a pale blue color results. Pyrrhotite when heated in the reduc- ing flame of the blowpipe, is fuseti to a magnetic globule. Niccolite when intensely heated gives off arsenic fumes. Metallurgy. The ores are roasted and smelted in blast furnaces, a 'matte' resulting which is a sulphide of nickel, copper and iron. The iron is removed in converters, leaving a product containing about 80% nickel and copper and 20% sulphur. This is refined and the nickel and copper separated, (1) by smelting in a blast furnace with salt cake and coke, (2) by crushing, dead roasting and reducing in a reverbera- tory furnace by charcoal, (3) by dead roasting and treating with sulphuric acid and water gas. NITRATES. The natural nitrates are found in many places in the desert, regions in the southern part of California, but no commercial production has as yet been made. For some time the principal supply of soda niter has come from Chile in South America, the saltpeter deposits of that country having for years been quite famous. Here the impure nitrate or ' caliche ' is first sorted and then refined before being marketed. The chief commercial source of niter or potassium nitrate has been France, Sweden and Germany. In the United States it has been found in caves in Kentucky, Indiana, and some of the Western States. It is believed that the origin of nitrate deposits is due to the nitrify- ing agencies of bacteria acting uj^on organic matter, by which means the nitrogen is converted into nitric acid, and this combines with the bases, lime, soda and potash. Industrial application and uses. Soda niter or CJtile saltpeter is probably the most widely used of all fertilizers, nitrogen being one of the most essential constituents in all animal and vegetable life. It is also used in making nitric acid and in the artificial manufacture of niter, by replacing the sodium with potassium. Niter is used in making gunpowder, fulminating powder, and for other pyrotechnic purposes; in the manufacture of nitric and sulphu- ric acid; and in a few cases as a medicine. Properties and ores. There are three nitrates of importance; thovse of sodium, potassium, and calcium. COMMERCIAL MINERALS OF CALIFORNIA. 71 Soda Niter (NaNOg) Nitrate of sodium called Chile saltpeter. Contains 36.5% soda (NaO) and 63.5% nitric anhydride (NOJ. When pure it is a white translucent salt, but in nature is often brown, yellow, or reddish. Vitreous luster, soft, hardness 1.5-2.0, specific ^n-'avity 2.24-2.29. By far the most common of the nitrates, and occurs as incrustations, massive or as crystals with perfect rhombohed- ral cleavage. Xifcr or Saltpeter (KNO..) Nitrate of potassium. Contains 46.5% potash (K2O) and 53.57c nitric anhydride (NOJ. Color white, vitreous luster, soft, liardness 2.0, specific gravity 2.1, taste salty and cooling. Occurs as incrustations, silky tufts or acicular crystals, on dry and protected places. Very rarely found in commercial quantities in the United States. Xifrocalcite (Ca(N03)o.nH20). Hydrous nitrate of calcium. Color white or gray, sharp bitter taste. Occurs in soft, silky tufts or masses. Distribution. The nitrates can only exist in solid form in dry, arid or desert regions. In such regions they are common as crusts, or tufts which are tlie result of evaporation of solutions. They have been found in Inyo, San Bernardino and Riverside counties. Tests. The nitrates may often be distinguished by their taste and appear- cuiee. Potassium nitrate and soda niter both burn vividly when thrown on live coals, the former giving a violet color and the latter the yellow sodium color. The soda niter deliquesces, or becomes liquid, upon exposure to damp air. When heated in a closed tube, or/ better, a bulb tube, with potassium bisulphate, all nitrates yield NOo gas which may be detected by its red color. Preparation. In Chile the crude nitrate or 'calicbe' is refined by crushing and treating with boiling water in tanks heated by steam coils, until it reaches a certain density, when it is run out to cool and crystallize. Certain impurities are left behind and the process is repeated until a sufficiently pure product is obtained. Xiter, or saltpeter, is prepared by scraping up the thin coatings, or deposits, lixiviating the material with water and then evaporating the solution. Potash is added to recover the calcium nitrate. 72 CALIFORNIA STATE MINING BUREAU. PETROLEUM. The United States is, by far, the greatest producer of petroleum in the world, the annual production being more than four times that of its nearest competitor, Russia. Mexico, the Dutch East Indies, Galicia, India and Rumania are also important producing countries. The production in the United States for the last few years has been around 300,000,000 barrels annually. The total production in California, since discovery, is greater than the total production of any other state, for an equal period. For many years, from 1903 to 1914 inclusive, with the exception of two years,- 1907 and 1903, California lead all the states in annual production. For those two years Oklahoma showed a greater pro- duction, and since 1914 it has been the leading state, with California a very close second. The industry in this state is described in detail in Bulletin No. 69, issued by the State Mining Bureau, entitled "The Petroleum Industry of California." This bulletin is accompanied by a folio of geological maps of the oil fields. The annual reports of the State Oil and Gas Supervisor, Bulletins Nos. 73, 82 and 84 respectively, and Bulletins, 3, 11, 16, 19, 31, 32, 63, contain much valuable information relative to the industry. The following brief data is taken from recent reports : There are 89,212 acres of proved oil land in California, cf which 57,499 acres are in Kern Count}^ Fresno County ranks second, with 13,319 acres. Other counties with acreages are: Santa Barbara, 9363; Orange, 3530; Los Angeles, 2873; Ventura, 1776; San Luis Obispo, 772; Santa Clara, 80. Tbe Midway-Sunset field in western Kern County has been, by quite a margin, the largest producing district, although about the same number of wells are operated in the Kern River field near Bakersfield in the same county. The average price for the whole state has increased from 47.9^ in 1915 to 63.6^ in 1916, 90.8^ in 1917, and $1.24 in 1918. The production in California in 1918 was 99,731,177 barrels, valued at $127,459,221. PHOSPHATE ROCK. The United States produces approximately one-half of the world's output of phosphate rock. The greatest deposits are located in Flor- ida, South Carolina, Tennessee, Kentucky, Arkansas, Wyoming, Idaho and Utah. Florida produces about 76% of the total. No deposits of commercial value have been located in California. I COMMERCIAL MINERALS OP CALIFORNIA. 73 Industrial application and uses. Phosphate rock is used almost entirely as a fertilizer. Phosphorus, togrether with nitrogen and potash, comprise the fertilizing materials that are essential to continuous producing soil. The phosphate rock is finely ground and used directly as a fertilizer, or it is treated with sulphuric acid in the production of super-phosphate. Due to its con- tent of phosphoric acid it is used in certain chemicals. Properties and ores. Phosphate rock is a sedimentary deposit containing calcium phos- phate. It is a hard rock found in beds between layers of sandstone, shale, or other sedimentary rock ; in stream deposits ; or as a residuum from the decomposition of limestone, dolomite or other rocks containing phosphate. Apatite (CaF)Ca4(P04)3, a fluoride of calcium, with fluorine and sometimes chlorine, is also a commercial source of phosphoric acid. In color it may be brown, green, yellow or pink, vitreous or greasy luster, hardness 5.0, specific gravity 3.17-3.23. Occurs massive or granular. Monazite is a phosphate of the rare earth minerals cerium, lan- thanum, didymium and thorium, and is a source of these minerals. Distribution. No commercial bodies of phosphate rock have as yet been located in California. Apatite has been found as crystals in many of the rocks of the state. The phosphate reserves in the United States are estimated to be 6,000,000,000 tons. Great areas of high grade material in the western states have been examined and classified. Tests. When a cold or slightly warm nitric acid solution of a phosphate is added to a solution of ammonium molybdate a yellow precipitate is formed. This is a delicate test. Only a small amount of the phos- phate solution should be added at first, as the precipitate will not form in an excess of phosphoric acid. This test may be made on the phosphate mineral itself by moistening with a drop of nitric acid and then applying a crystal of ammonium molybdate, when the yellow color will spread over the mineral. Many phosphates when heated before the blowpipe, or when moistened with concentrated sulphuric acid and then heated, give a pale bluish-green color to the flame. 74 CALIFORNIA STATE MINING BUREAU. PLATINUM. The United States before the war apparently used about 165,000 fine ounces of platinum per year. The imports for several years prior to 1914, averaged around 118,000 troy ounces. The domestic pro- duction was very small, approximately 600 to 800 ounces yearly. Considerable platinum is recovered from the refining of blister copper, and much secondary metal is derived -from refining scraps and sweep- ings. The imports have steadily decreased for the last few years until in 1917 they were only about one-fourth of the pre-war figure. Cali- fornia is the largest producer in the United States. In 1918 the pro- duction from this state was 571 ounces of crude platinum-group metals, valued at $42,788. In the past about 95% of the world's supply has come from the Ural Mountains in Kussia, but this supply has been cut down about one-third in the last two years. Columbia is the next largest producer. In 1915 California miners received from $28 to $38 per ounce for crude platinum. In 1916 this had increased to from $43 to $76 per ounce. The quotation on the pure inetal was often over $100 per ounce in 1916 and 1917. I Industrial application and uses. Platinum in the form of wire, foil, crucibles, and dishes of various shapes and sizes, is absolutely necessary in chemical laboratories. Upon such laboratories all great industries depend for guidance. It has wide. application in instruments of precision, and in the electri- cal industry, telegraph and telephone apparatus, etc. At present one of its most important uses is in the contact process of making con- centrated sulphuric acid. As a war metal its alloys with iridiunij osmium, and the allied metals are needed for electrical equipment on aeroplanes, trucks, tractors, and instruments used by the signal and medical corp. For many of the delicate parts mentioned above, there is no substitute for platinum. Considerable amounts are used in dentistry and in the making of jewelry. Properties and ores. Pure platinum (Pt.) is a lustrous, grayish-white metal, quite mal- leable and ductile. Hardness 4.0-4.5. Gravity 14.0-19.0, very heavy. Generally occurs in small grains or nuggets of a size to pass a twenty- mesh screen, associated with gold-bearing placers. It has not yet been found in place in California, hence has not been detected as a con- stituent of the rocks, but its origin no doiibt lies in the basic igneous rocks which alter to serpentine. It has been found in such associations in Russia and in British Columbia. Crude platinum is generally an COMMERCIAL MINERALS OP CALIFORNIA. 75 alloy of from ol'/^ to 85% platinum, the remainder being iridium, osmium, and the allied rarer metals. Considerable platinum is now recovered in the electrolj'tie refining of blister copper. It has been found that this product often carries from 0.34 to 1.8 ounces of platinum and from 0.6 to 4.4 ounces of • palladium per 100 tons of blister copper treated. Distribution. 4 The characteristic occurrence of platinum in California is in metallic I grains associated with the gold-bearing black sands of the stream I beds, placers and beach sands. It is found in a great many localities, * and the greatest amount is recovered by the many gold dredges now in operation, principally in Yuba, Sacramento, Butte and Calaveras counties. Hydraulic and surface sluicing mines in Del Norte, Hum- boldt, Siskiyou and Trinity counties have yielded considerable amounts. ^Merced. Stanislaus, Nevada and Shasta counties are smaller producers. Tests. Distinguishing qualities are its malleability, high specific gravity, extreme infusibility and insolubility in any single acid. It can be dissolved in aqua regia, a mixture of 3 parts of hydrochloric acid and 1 part nitric acid. It will not amalgamate with quicksilver alone, Init will amalgamate if sodium is added. Simple tests are as follows: Dissolve in aqua regia and evaporate to dr\'ness. Dissolve again in i ydroehloric acid alone, and evaporate until thick, but not quite dry. Add distilled water, a few drops of sulphuric acid, and potassium iodide solution. In the presence of platinum a wine red color will result. Potassium chloride or ammonium chloride will give a yellow precipitate. To test black sand, put a small amount in a test tube, add hydro- chloric acid and nitric acid in the ratio of 2 to 1, warm for a few minutes, pour out this solution and again add acid in same ratio and boil. Pour what remains of the solution over a filter paper and then add stannous chloride. An orange color will appear if platinum is ]^ resent. Gold gives a red purple or brown purple color. Metallurgy. \ The metal is obtained from the gravel and sand, by classification, concentration and amalgamation with electrol.vtic sodium amalgam. Within recent years the dredging and hydraulic mining companies have given close attention to saving the platinum, and the above method is the one in general use. 76 CALIFORNIA STATE MINING BUREAU. Albert H. Sherwood of Oroville has patented a process for the re- covery of fine gold and platinum, in which the sands are treated with an acidulated solution of copper sulphate, the platinum particles becoming copper plated after which their amalgamation with ordinary amalgam is a simple matter. POTASH. Before 1915 the United States was almost wholly dependent upon Germany for its potash supply. The normal annual importation be- fore the war was about 250,000 short tons (reckoned as K2O) with a value around $15,000,000. This represented over 1,000,000 tons of all classes of potash material. There was practically no domestic production. In 1916 and 1917 the imports were reduced to about 3000 tons K^O. The demand "had increased to a great extent during this period, due to its use in the manufacture of powder, signal rockets, fertilizer, etc. The country was therefore suddenly thrown upon its own resources in this regard. The 1916 production was not very encouraging, the principal output being from California, which produced 17,908 tons valued at $663,605. However, in 1917 the output of this state in- creased to 138,760 tons valued at $4,098,106. Prices for German potash salts delivered in the United States, before the war, ranged from $8.25 for 12|% K.O to $38 per ton for material containing 50% K2O. In 1917 it is estimated that 50% K.O brought $213 per ton. Industrial application and uses. ' Potash is used principally as a fertilizer and for some crops its application is now regarded as essential. It enters into the manufac- ture of nearly all explosives,- fireworks, etc., as saltpeter (potassium nitrate). Ordinary black powder is 75% saltpeter. In the manufac- ture of matches, potassium chlorate is extensively used. Other numer- ous uses are in the manufacture of soap and glass, and in dyeing, tanning and metallurgy. Properties and ores. Potassium (K) is the basis of all potash salts or compounds. It is a soft, silver white metal, so light that it floats upon water, its specific gravity being 0.86. It has a brilliant metallic luster which soon disappears in the air, owing to rapid oxidization. It is therefore usually seen covered with a grayish coating and must be kept under oil. In combination with oxygen it forms potassium oxide, K^O, mm COMMERCIAL MINERALS OF CALIFORNIA. 77 known as potassa, but commonly called 'potash,' because it was first prepared by evaporating the solution of ashes in iron pots, hence * pot- ash. ' The material thus obtained was an impure potassium carbon- ate (K0CO3), a white powder which absorbs moisture from the air, and is very soluble in water, and has a strong alkaline reaction. The term was afterwards used to include 'caustic potash' (KOH) com- monly known as lye, which is produced by treating potassium car- bonate with lime (CaO). The form K._.0 is now commonly used as a standard in speaking of potash products. Potash salts are generally sold, however, as potassium sulphate (K2SO4), potassium chloride or 'muriate' (KCl), potassium nitrate (KNO,). and potassium carbonate (K0CO3). Potassium chloride closely resembles common salt (NaCl) in color, taste, etc. Potassium nitrate is also called 'niter' or 'saltpeter.' It is a white .^olid, which dissolves readily in water. At high temperature it gives off oxygen easily, and this led to its extensive use in explosives, matches, etc. Potassium sulphate is used principally as a fertilizer. The principal sources from which potash has been produced are from natural salts and brines, silicate rocks, furnace dust, kelp, wood ashes, distillery waste and miscellaneous organic sources. Alkali lakes, prin- cipally in western Nebraska and California, have furnished the most readily available supply and the largest output. Great progress has been made in the last few years in the extraction of potash from kelp. Distribution. h^ At Searles Lake in San Bernardino County there is a great deposit "of potash salts and a less important one at Owens Lake, Inyo County. Active operations are in progress at both of these deposits. Around Los Angeles and San Diego, during 1915-1918, several companies extracted potash from kelp. It is estimated that there are 225 square miles of commercially valuable beds of kelp along the coast of South- ern California. The raw or wet kelp yields 10% dry material and this latter contains about 12% K^O. At Riverside, Victorville and Santa Cruz potash is recovered as a by-product in the manufacture of cement. Tests. Volatile potassium compounds when heated in a non-luminous (blue) flame, such as given by an alcohol lamp or blowpipe, will produce a characteristic violet color. The test to be made with a little of the solution of the mineral on a clean platinum wire. Before testing dip the wire in hydrochloric acid and lieat. Organic substances may be burned and the ashes tested in this way. 78 CALIFORNIA STATE MINING BUREAU. PUMICE AND VOLCANIC ASH. For many years the principal supply of commercial pumice has come from the Lipari Islands, off the coast of Italy. This supply has in the past few years been largely shut off. Deposits of commer- cial value of pumice and volcanic ash have been found in this country in California, Kansas, Nebraska and other states. Industrial application and uses. Pumice is used as a polishing and scouring material, and volcanic ' ash is used in the manufacture of scouring soaps and polishing pow- , ders. Pumice is used to a great extent by painters for smoothing and polishing surfaces of carriages, automobiles, etc., or any surface that requires an excellent finish. Recently, light volcanic material of sufficient strength has been tested for use as aggregate in concrete for ship-building. Properties. Pumice is a glassy volcanic rock, which has a very porous or scoria- ceous structure due to the expansion of gases and vapor, while in a molten state. It is light, spongy and froth-like in appearance, white or gray in color, hard and brittle. The cutting or abrasive quality is due to the thin partitions of glass composing the walls between the vesicles. Volcanic a.sh is material of a much finer nature, being broken and powdered by volcanic explosions. Both are in general of rhyolitic or andesitic composition. Distribution. During the summer of 1917 inquiry was made by the State oMining Bureau* regarding the location of deposits of pumice, volcanic ash and vesicular lava in this state. There is an extensive deposit of coarsely porous pumice in eastern Siskiyou County which has been tested in concrete which was to be used for heat insulation. It gave a very light concrete with superior heat-resisting qualities, but. too low in compressive strength to be of use. More recently, another deposit of finer grained block pumice has been opened in this same district, and several hundred tons are said to have been shipped during 1918 to the east. This pumice has been tested in concrete and i-ave a product light enough to float half submerged in water. This concrete was probably strong enough for ordinary construction requirements, but could not meet the high strength standard set for concrete shipbuilding. It is quite likely ♦By C. A. Logan, Field Assistant. COMMERCIAL MINERALS OF CALIFORNIA. 79 that piunice may soon come into use as an aggregate in concrete where light weight is desired and moderate strength is sufficient, as, for example, in small buildings, floors and partitions. Its fireproof and heat-insulating properties would make it attractive for such uses. Experimental work in this direction has been discouraged by high cost of transportation from the known deposits to centers of population. Volcanic ash or tuff is widely distributed in California, large deposits of fair quality being found near transportation in Napa, Madera, San ^ Luis Obispo, and other counties, particularly in the southeastern desert region. Besides its industrial uses, tliis ash, when sufficiently con- solidated by natural agencies, has been found suitable for building small bridges and buildings and for road material in the localities where it occurs. Some samples of such tuff gathered by the State Alining Bureau last summer showed great compressive strength and very light weight, but have not been thoroughly tested in concrete. Vesicular Ir\r from California has been tested as aggregate in con- crete and gave a product possessing great compressive strength and weighing only about two-thirds as mucli as ordinary concrete. Un- fortunately our deposits of this rock near transportation are, so far as known, confined to the desert regions from ^lono Lake southw^ard. In Imperial County there is a deposit of vesicular block pumice, which has found a ready market. Tests. This class of material is easily distinguished by its physical proper- ties, especially its porous, vesicular structure, and its lightness. The deciding factors as. to whether or not a deposit is of commercial value are nearness to transportation, lightness and strength. PYRITES. Industrial application and uses. Pyrites are used mainly for the manufacture of sulphuric acid. There are two classes — lump and fines — the lump, commanding some- what higher prices. For commercial value the sulphur content should be over 40% and very few of the acid companies wall accept material that carries less than 35% sulphur. Certain elements such as arsenic and antimony are harmful, and also carbonaceous material is objection- able. Low-grade acid made from impure pyrites is used in fhe manu- facture of fertilizers. Properties and ores. The term pyrites is the general trade name for the several iron sulphide minerals such as pyrite, marcasite, and pyrrhotite. 80 CALIFORNIA STATE MINING BUREAU. Pyrite and marcasite (FeSg) have identical chemical composition and when pure contain about 47% iron and 53% sulphur. They differ, however, in crystallization. Pyrite is pale brass-yellow in color, streak black to brownish or greenish, metallic luster, hardness 6.0-6.5, specific gravity 6.0. Gen- erally found in cubes or octahedrons. It is the most common of the sulphide minerals and is found in all kinds of rocks, but is more prominent in metamorphic schists, slates, etc. and in unaltered sand- stones. Common in gold districts, and it is from pyrite bodies that most of the copper production of the state is obtained. Marcasite, called white pyrites, is pale yellow to almost white in color, with black somewhat grayish streak, metallic luster, hardness 6.0-6.5, specific gravity 4.85-4.9. Commonly in tabular crystals, also massive. Cannot be easily distinguished from pyrite, except when in crystals. Much more rare than pyrite and characteristically associated with clays and cinnabar. Pyrrhotite (Fe^S^) or (Fe^Sis) or (FcnS.n+i) Magnetic pyrite.s. Color brown or bronze, streak grayish black, metallic luster, hardness 3.5-4.5, specific gravity 4.58-4.64. Usually slightly magnetic. Com- monly massive, granular or compact, sometimes in large lenticular masses. Associated w^ith pyrite. Found in gold and copper districts, and often carries nickel. Masses occur in serpentine and pegmatite veins. Occurrence. In 1918 pyrite was produced in Alameda, El Dorado and Shasta counties. It occurs in many localities in other counties, but not generally in such quantity or quality, or not so economically situated as to be of value commercially. Tests. Pyrite and marcasite when heated in the closed tube give mucli sulphur. Pyrrhotite when similarly treated gives little or no sulphur. All are magnetic when heated before the blowpipe. Pyrite dissolves completely if a little of the very fine powder is treated in a test tube with concentrated nitric acid. It should be allowed to stand, cold, until vigorous action ceases and then boiled. The nitric acid should be strong enough to decompose the mineral completely before heating. Marcasite when treated as above yields some separate sulphur. Th( nitric acid solutions of iron compounds are yellowish in color, and when ammonia is added in excess, brow^nish red precipitates of ferric hydroxide are produced. COMMERCIAL MIIS^RALS OF CALIFORNU. 81 SULPHURIC ACID. Sulphuric acid is manufactured by bringing together, under suit- able conditions, sulphur dioxide (SOJ, oxygen (0) and water (HgO), as steam, in the presence of certain oxides of nitrogen. The latter simply act as carriers of the oxygen. The oxygen, water and sulphur dioxide combine to form sulphuric acid (H2SO4), but the reactions are much more complicated than the mere union of these substances. QUICKSILVER OR MERCURY. California produces about 75% of the quicksilver mined in the United States. The production in 1918 was 22,621 flasks, valued at i $2,579,472. fndustrial application and uses. By far the greatest consumption is in the manufacture of fulminate for explosive caps and in drugs. It is an absolute necessity from a military' standpoint, as there has not yet been found a substitute for it in the manufacture of fulminating caps. In the recovery of gold and silver the mercury is placed on amal- gamation plates both inside and outside the stamps and collects the fine particles of gold. Ordinary calomel is mercurous chloride (HgCl), and the bichloride has an extensive use as a disinfectant. Much mercury is used in scientific apparatus, such as thermometers, barometers, etc., and in many electrical appliances. Properties and ores. Mercury (Hg) is a bright silvery metal, distinguished by being the only one which is liquid at ordinary temperatures. It was from this fact that it received its comman name of quicksilver. The Latin name from which the symbol Hg. is derived means literally 'water silver.' It is very heavy (specific gravity 13.59), and slightly volatile at ordinary temperatures, the vapor being poisonous. It does not tarnish in the air unless sulphur compounds are present. Cinnabar (HgS), sulphide of mercury is the most important ore. Contains 86,2% mercury and 13.8% sulphur. Distinguished by its brilliant red color and adamantine luster. The streak is scarlet red. Quite soft (hardness 2.0-2.5) and very heavy (specific gravity 8.0-9.0). Perfect prismatic cleavage. Generally occurs massive and granular, but small crystals are common. Globules of free mercury are often found with the cinnabar in many of the mines. 6-24S4 82 CALIFORNIA STATE MINING BUREAU. Metacinnaharite (HgS), the black sulphide of mercury, has the same composition as cinnabar, but is grayish black in color, has a black streak, metallic luster, hardness 3.0, specific gravity 7.81. Usually massive and amorphous. Found in many of the cinnabar deptisits in the state. Distribution. Cinnabar was known in this state long before the discovery of gold. The .most important deposits lie in the Coast Ranges, extending from Del Norte to Santa Barbara County. San Benito is the largest pro- ducing county followed in order by Santa Clara, San Luis Obispo, Napa, Lake, Sonoma, Solano and Colusa counties. Small quantities are also found in Kern, Kings, Monterey, Santa Barbara, Stanislaus and Trinity counties. The New Idria Mine in San Benito County is the largest producer in the United States. The other producing .states, are Nevada, Texas, and Arizona. Tests. Cinnabar may be distinguished by its brilliant color, streak and luster. The most satisfactory test is the formation of metallic mercury when heated in the closed tube with sodium carbonate. A little of the powdered mineral is mixed with about four volumes of dry sodium carbonate, placed in a closed tube, covered with an additional layer of sodium carbonate and then heated gently. Metallic mercury will, distill off and collect as globules on the sides of the tube. When heated alone in the closed tube, gives a black sublimate (HgS.) Gives sulphur dioxide (SOo) aud free mercury when heated in the open tube. Metallurgy. Mercury is obtained from its ores by a combined roasting and dis- tilling process. The ore is heated in furnaces, the mercury is vaporized and is then collected in condensers. The roasting may be performed in shaft-furnaces of the Scott type, or in rotary furnaces. The condensers are long series of ])rick or cement chambers, or curved pipes cooled by water. SALT. Salt is very abundant and widely distributed in the United States. The production is always able to meet domestic requirements, despite- unfavorable conditions of operation from time to time. There is a very small export and import trade. The largest part of the pro- duction is obtained by converting the natural rock salt into brines,. COMMERCIAL MINERALS OP CALIFORNIA. 83 pumping this brine to the surface and there evaporating it. Almost ;;s great a quantity is produced by evaporating the natural sea water, while in 1917 about 1,600,000 tons of rock salt were mined in the iiatural state. Large quantities are also obtained from natural brines. Michigan has for many years been the largest producer, followed closely by New York. Other principal producing states in order are: Ohio, Kansas, California, Louisiana, Texas and Utah. Most of the salt produced in California is obtained by evaporating the ocean water, plants being located on the coae, and which is known as Moh's scale. It is as follows: (1) Talc, (2) Gypsum, (3) Calcite, (4) Fluorite, (5) Apatite, (6) Feldspar, f7) Quartz, (8) Topaz, (9) Corundum, (10) Diamond. The place which a mineral occupies in this scale is determined by the ease with which it scratches, or with which it is scratched by the minerals mentioned. Thus, if upon trial, a certain mineral is found to scratch feldspar but in turn is scratched by quartz, it would have a hardness of between 6 and 7 or say 6.5. In testing, a sharp point or corner of one mineral should be used upon the smooth face of another, and care should be taken to distinguish between hardness and brittleness. Brittle minerals often crumble or break down, and appear to be soft, whereas if due care is taken ihej are found to be a great deal harder than it would seem. Also, in some cases it will take close observation to distinguish between a mark or streak left by one mineral on another and an actual scratch. Common methods of testing for hardness are with the finger nail, which scratches talc easily and gypsum with difficulty; a copper coin whose hardness is 3.0; pin point, hardness about 3.5; knife blade hardness a little over 5; and ordinary window glass, hardness 5.5; quartz crystal hardness 7.0; small piece of corundum, hardness 9.0. With practice the hardness of a mineral can be closely approximated by the ease with which it is scratched with a knife blade. Specific gravity. The specific gravity of a substance is the ratio of its weight to the weight of an equal volume of water. The weight of water (62.5 pounds per cubic foot) is taken as one. Thus metallic lead has a specific gravity of 11.37, whicli means that it is 11.37 times heavier than water. Careful laborator^^ work is necessary to accurately determine the spec- ific gravity of a mineral sample, but with practice, and with the aid of several common substances or minerals, whose specific gravities are known, close approximations can be made. Common substances with specific gravities are as follows: Borax, 1.7; sulphur, 2.1; halite (common salt), 2.1; serpentine, 2.5-2.6; quartz and granite, 2.6; talc, 106 CALIFORNIA STATE MINING BUREAU. 2.8; magnesite, 3.0; chromite, 4.2-4.6; barite, 4.5; pyrite, 5.0; cuprite, 6.0; scheelite, 6.0; iron, 7.3; galena, 7.6; copper, 8.8; silver, 10.5; gold, 19.3. Color. The color of a mineral may be very distinct and characteristic, as in the case of cinnabar, or it may vary through almost every shade as is shown by fluorite, quartz and tourmaline. In observing the color, care should be taken to obtain a fresh, unaltered sample. Dark minerals often require a close examination for a distinguishing shade of deep green, brown, etc., and a small or thin piece will often bring out a distinct color in a mineral that appears absolutely black and opaque. Frequently a mineral is colored by some foreign substance with which it is merely mechanically mixed, and in this case the color is misleading. I Streak. ^ The streak of a mineral is merely the color of the very fine powder. This is easily obtained by rubbing the sample on a piece of white unglazed porcelain. The streak often gives a delicate shade not shown in the lump sample of the mineral. Luster. The luster of a mineral is the appearance of the surface due to its reflection, refraction or absorption of the light. Common lusters defined are as follows: Adamantine, the brilliant luster of the diamond. Shown by only a few other gem stones, and a few minerals such as cinnabar and cerussite. Vitreous, glassy, like the luster of glass. Besinous, having the appearance of resin. As sphalerite. Greasy or oily, as if the mineral had a thin coating of oil over it. Pearly J like mother of pearl. Silky, like a skein of silk. Observed on minerals which have a fibrous structure. Metallic, the characteristic luster of the metals as silver, lead or copper, and many common ores as pyrite, galena, etc. Under thia head are included those minerals which are opaque. Suhmetallic, dark colored minerals which have a somewhat shiny appearance, yet cannot be said to have the true luster of the metals. Chromite is an example. COMMERCIAL MINERALS OF CALIFORNIA. 107 Cleavage. Many minerals have a tendency, due to crystallization, to break readily in certain directions, and when thus broken present smooth surfaces, resembling crystal faces. This property is called cleavage. Good cleavage may be exhibited in only one direction, or in several directions, and it may be a great deal more distinct in one direction than in another. Direction of cleavage may be indicated by the presence of minute cracks through the crystals or may often be easily determined by striking the mineral a sharp quick blow with a hammer. The most common cleavages are cubic, as shown by galena, rhomha- Jedral as in calcite, hasal as in the micas, prismatic when produced with equal ease in two directions, parallel to certain faces, as in amphibole. structure. The common form or appearance of a mineral, due to crystallization, or absence of crystal form. Common structures are: Granular. The structure of a mineral which consists of an aggre- gate of small crystalline particles of about the same size. Compact or earthy. Like clay. Massive. When no crystal faces can be seen, although the mineral may possess a crystalline structure. Amorphous. When no trace of crystalline structure exists. Columnar. Made up of columns or prisms nearly parallel. Fibrous. Fine fibres or shreds arranged in parallel groupings, as asbestos. Schistose. The flattened or banded appearance of some metamor- phic rocks, due to great pressure. Foliated. When a mineral may be separated into flat plates, of more or less irregularity in shapes and thickness. Micaceous. Like foliated, only more perfect. May be split easily into exceedingly thin sheets, as mica. Radiated. When columns or fibres radiate from central points, as in pectolite. Reinform of m^ammillary. Smooth, rounded, interlocking or over- lapping masses, grouped in kidney shapes, as in some varieties of hematite. Botryoidal a7id globular. Groupings of small rounded or spherical nodules, more or less interlaced or overlapped, as in smithsonite. Stalactitic. Icicle, or pendant like. 108 CALIFORNIA STATE MINING BUREAU. Porous, cellular, vesicular, pumiceous. Full of small irregular cavities. Fracture. Some minerals possess a characteristic fracture when broken, such as obsidian or volcanic glass. This shows a smooth curved surface resembling a shell, and is said to have a conchoidal fracture. Other common fractures are uneven, when rough or irregular, Jiackly, when jagged, and splintery when the substance breaks into splinters or needles. Other physical properties. Other physical properties of metals, ores or minerals are as follows: Malleable, when it can be hammered into plates. Ductile, when it can be drawn into a fine wire. Sectile, when it can be cut with a knife. Flexible, when it bends easily, but does not regain its original position. Elastic, when it bends easily, but springs back into position. Brittle, when it breaks into pieces under slight pressure. APPARATUS FOR TESTS. A short description is here given of the apparatus and methods mentioned under the tests for the different minerals. Three methods will cover the tests as mentioned in this bulletin: first, observation ' of the physical properties or peculiarities of the minerals or ores; second, tests with acids or solutions; third, tests by heating, igniting, or fusing. The physical properties are described under that heading. In regard to tests with acids care should be exercised in handling, heating, etc. Do not add cold water to very hot solutions. Test tubes containing solutions should be heated gently and not thrust directly into the flame and held there. The mouth of the tube should always be held away from the face. Heating over a piece of ordinary fine wire screen will prevent breakage. Only a very small amount of powdered mineral need be used for a test. Usually an amount that can be picked up on the point of an ordinary knife blade will suffice, and only enough acid should be used to cover the mineral well. In general, for minerals without metallic luster, hydrochloric acid is the most convenient solvent, while for sulphides and arsenides, which usually have a metallic luster, nitric acid is best. Strong evolution of gas should be guarded against. COMMERCIAL MINERALS OP CALIFORNIA. 109 In the test by heating, it is best to have access to an ordinary gas jet, but many of the tests may be made by heating in other simple ways as mentioned. Apparatus mentioned is described as follows: B 1(71 sen hxirner. This consists simply of a metal tube about one- half inch in diameter and six inches high,- mounted on a base and attached to the gas jet by means of a hose. The gas enters at the bottom and is mixed with air which comes through two holes in the tube near the entrance jet. A cylindrical ring is provided to fit over the tube with holes corresponding to the air holes in the tube, and with which the supply of air can be regulated. The mixture of gas and air should be such that the burner gives a blue flame with a distinctly outlined inner cone. The outer portion is the oxidizing flame, while the inner cone is the reducing flame. The blowpipe. The common blowpipe consists of a tapering brass tube, about eight or ten inches in length and of small diameter, vary- ing from one-quarter to one-thirty-second of an inch. The lower, smaller end is curved and terminates in a small bulb in which there is an opening as large as a pin point. The blowpipe is used in con- junction with the Bunsen burner flame. The tube is placed in the mouth, the cheeks extended and a continual and steady current of air forced through. The tip is placed sidiewise in the flame in such a manner that a jet of flame is forced to one side and downward upon the sample of mineral, which is usually carried on a piece of charcoal. The flame produced in this manner is intensely hot, and is similar to that of the Bunsen burner, the outer cone being the oxidizing flame, while the inner one is the reducing flame. Some skill and practice is necessary in order that the blowpipe be operated successfully. Closed tubes are made from ordinary glass tubing from one-eighth to one-quarter inch in diameter, cut into lengths of three or four inches and sealed at one end. They are used for heating substances with slight access of air. Open tubes are pieces of ordinary glass tubing about six inches long, slighth' bent in the middle and open at both ends. Used for heating substances in free circulation of air. 110 CALIFORNIA STATE MINING BUREAU. BIBLIOGRAPHY. Publications of the United States Geological Survey, Department of the Interior, Washington, D. C. The following is a brief summary of the publications of the United States Geological Survey, complete . catalogues and indexes of which will be found at libraries where such publications are on file, or may be obtained by writing to the department at Washington, as indicated above. Many of the publications are for free distribution. Annual reports. Issued by the Director of Survey to the Secretary of the Interior at the end of every fiscal year. Essentially a report on the work accomplished during the year, giving results of special investigations or research work ; a brief abstract of publications of the year, and a summary of work by branches and divisions. Also gives maps showing the progress of topographic and geologic surveys. Monographs. Exhaustive treatises or reports on research work dealing with many special subjects, or investigation of certain districts, along the lines of geology, paleon- thology, etc., written by some of the foremost scientists. Professional papers. Detailed descriptions of particular regions, or special subjects, coverinii* a wide range of subjects as regards ore deposits, geology, water supply, forests, plants and animals, etc. Often accompanied by plates and maps. Bulletins. Discussions, descriptions and research work covering a great variety of subjects such as mineralogy, chemistry, geology and various ores, and numbering at present over 700. Water supply papers. Reports on, and results of, surveys on water supply, in all parts of the United States, dealing with surface and underground waters, rivers, drainage, etc. Mineral resources of the United States. Part I. Metai>s. Issued annually. Describes in detail the production, value, etc., of all the metals found in the United States. Gives production by states and describes the principal pro- ducing localities, characteristic occurrences in the different districts, exports, imports, gives data on commercial importance, uses, as well as total world pro- duction. Separate pamphlets are issued on certain minerals or groups of minerals which are naturally associated, or Avhose production is confined principally to a certain district. Part II. Non-Metals. Issued annually. Same as above, only deals entirely with the non-metals. Separate pamphlets on each mineral, issued as soon as possible after data is procured and before they are incorporated into final bound volume. These are available for distribution from August to December of the succeeding year. Special publications. A few preliminary reports, and results of surveys in Alaska. Topographic and geologic atlas of the United States. When completed this will comprise a survey of the entire United States, showing in detail the topography and the geology. The maps are of convenient size and bound in folios, along with descriptive matter on the district treated. Each map represents an area called a quadrangle which is bounded by parallels of 1 1 latitude and meridians of longitude. Three scales are used, i. e., • 250,000 125,000 1 and 62,500. The separate sheets on topography or geology may also be obtained. Maps are: issued showing areas which have been completed. COMMERCIAL MINEILVLS OF CALIFORNIA. Ill Publications of the Bureau of Mines, Department of the Interior, Washington, D. C. (Catalogues and indexes of publications may be obtained by addressing the Department as above, or may be consulted at technical libraries.) Bulletins. Scientific discussions, experiments and information on a great variety of subjects pertaining to mining and metallurgy, numbering at present about 200. Technical papers. Comparatively short discussions on many special subjects relating to mining. Publications of the California State Mining Bureau. A list of publications is given in the back of this bulletin and a Catalogue is also issued, free of charge, which gives a short description of all bulletins, reports, etc. REFERENCES. Particular reference was made in the preparation of this bulletin to the following : Bulletin No. 67, Minerals of California. Description of all minerals found in California with localities where each occurs. Lists of principal ores of the commercially important minerals, and lists of minerals found in each county. Bibliography on California minerals. California Miner^vl Production for 1915, 1916, 1917 and 1918, Bulletins Nos. 71, 74, 83 and 86, respectively. Statistics on the production and value of minerals in California for each year, together with other information on uses, etc. Gives production by counties, and also contains county maps. Preliminary Report No. 3, Manganese and Chromium. Description of the ores, uses, occurrence and prices, with list of producers and buyers of manganese and chromium in California, with a short chapter on the concentration of chrome ores. Preliminary Report No. 4, Tungsten, Molybdenum and Vanadium. Gives properties, ores, uses, occurrence, price, producers and buyers of metals mentioned. Preliminary Report No. 5, Antimony, Graphite, Nickel, Potash, Strontium, Tin. Gives properties, ores, uses, occurrence, prices, producers and buyers of metals mentioned. Also : Outlines of Industrial Chemistry. By F. H. Thorp, PJi.D. 1905. The Non-metallic Minerals. George P. Merrill. 1904. Determinative Mineralogy and Blowpipe Analysis. George J. Brush and Samuel L. Penfield, 1906. Manual of Mineralogy and Petrography. James D. Dana. 1918. Descriptive Chemistry. Lyman C. Newell, Ph.D. 1906. Mineral Deposits. Waldemar lAndgren. 1913. STANDARD TEXT OR REFERENCE BOOKS ON MINERALS AND ROCKS. Catalogues of the standard reference and textbooks on minerals and ro(^s, mining, geology, assaying, metallurgy, prospecting, etc., giving short descriptions of each work, may be obtained from the following publishers : Mining and Scientific Press, Technical Book Department, 420 Market street, San Francisco. John Wiley and Sons, Publishers, New York. McGraw Hill Book Company, Tenth Avenue and Thirty-sixth street, New York. D. Van Nostrand Company, New York. Macmillun Company, New York. 112 CALIFORNIxV STATE MINING BUREAU. SELECTED BIBLIOGRAPHY ON MINERALOGY AND THE IDENTIFICATION OF MINERALS. Prepared by R. W. Gannett and C. T. Robertson. Published by the Bureau of Mines, Department of the Interior. Bramble, C. A. The A B C of mining, 1898, 183 pages. Rand, McNally and Company, Chicago, 111. $1.00. Prospecting, methods of testing and assaying ores, surveying, camp life, and general mining are briefly discussed in simple language. Although much of the book is now out of date, the discussion on prospecting and camp life is particularly valuable. Brush, G. J. Manual of determinative mineralogy, with an introduction on blow- pipe analysis ; revised and enlarged by S. L. Penfield. Edition 16, 1909, 312 pages. John Wiley and Sons, New York, N. Y. $3.50. A standard reference book for blowpipe determination of minerals. Bnrdick, A. J. Valuable minerals ; how to find and know them. 1916, 42 pages. Gateway Publishing Company, Beaumont, California $0.50. A non-technical pamphlet giving excellent notes on prospecting and testing of minerals. It does not pretend to be comprehensive. Butler, G. Af. Handbook of mineralogy, blowpipe analysis, and geometrical crystal- lography. 1916, 546 pages. John Wiley and Sons, New York, N. Y., $3.50. This is a combination of three books issued previously as follows : Pocket handbook of minerals. Edition 2, 1912, 311 pages, $2.50 ; Pocket handbook of blowpipe analysis. 1910, 80 pages, $0,75 ; Manual of geometrical crystallography, (treating solely of those portions of the subject useful in the identification of minerals. Edition 1, 1918, 155 pages, $1.50. Cahen, Edward, and Wooten, W. O. Mineralogy of the rarer metals, a handbook for prospectors. 1912, 211 pages, J. B. Lippincott Company, Philadelphia, Pa. $2.50. Discusses all the rare metals under the headings of the detection, proper- ties, metallurgy, industrial application, annual production, and value. Cox, S. H. Prospecting for minerals. Edition 7, 1918, 260 pages, J. B. Lippin- cott Company, Philadelphia, Pa. $2.25. Hints on geology, a description of properties of minerals, tables of determinations, and a discussion of nonmetallic minerals, or ores, and of fuels. This book is probably the least technical of any of those named in this list. Daly, R. A. Ig-neous rocks and their origin. 1914, 563 pages. McGraw-Hill Book Company, Incoi-porated, New York, N. Y. $4.00. A standard reference book on the origin of igneous rocks and their petrologic characters, Dana, E. 8. Minerals, and how to study them. Edition 2, 1897, 380 pages. John Wiley and Sons, New York, N. Y. $1.50. A book for beginners in mineralogy, Duna, E. 8. Textbook of mineralogy, with an extended treatise on crystallography and physical mineralogy. New edition, entirely rewritten and enlarged, 1916, 593 pages. John Wiley and Sons, New York, N. Y. $1.25. Eakle, A. 8. Mineral tables for the determination of minerals by their physical properties. 1904, 73 pages. John Wiley and Sons, New York, N. Y, $1.25. Erni, Hen\ri. Mineralogy simplified, revised by Amos P. Brown. Edition 4, 1908, 414 pages. H. C, Baird and Company, Philadelphia, Pa, $2.50. Easy methods of identifying minerals, including ores. Contains physical tables for the determi- nation of minerals by their physical characters. Ford, W. E. Dana's manual of mineralogy for the student of elementary miner- alogy, the mining engineer, the geologist, the prospector, the collector, etc. Edition 13, revised, 1916, 460 pages. John Wiley and Sons, New York, N. Y. $2.00. A standard textbook. Frazer, Persifor, and Brown, A. P. Tables for the determination of minerals by physical properties ascertainable with the aid of a few field instruments. Edition 6, 1910, 125 pages. J. B. Lippincott Company, Philadelphia, Pa. $2.50. 'l^'lls how to identify minerals principally by their outward characteristics. (ivorge, R. D. Common minerals and rocks; their occurrence and uses. Colorado Geological Survey Bulletin No. 12, 1917, 463 pages. A descriptive mineralogy, rather technical in its form. A discussion of the main rock types is also given. Until the edition is used up, a copy can be obtained free from the Colorado Geological Survey, Boulder, Colo. Hatch, F. H. Mineralogy. Edition 4, 1912, 253 pages. The Macmillan Company, New York, N. Y. $1.40. A standard textbook. COMMERCIAL MINERALS OF CALIFORNIA. 113 Kvmp, J. F. Handbook of rocks, for use without the microscope. Edition 5, 1911, 272 pages. D. Van Nostrand Company, New York, N., Y. $1.50. Gives a glossary of the names of the rocks. It is a standard textbook and guide in field classification of rocks, for students, mining men and geologists. Contains glos- sary of the names of rocks and othen lithological terms. Kraus, E. H. and Hunt, W. F. Tables for the determination of minerals by means of their physical properties, occurrences, and associates, 1911, 254 pages. McGraw-Hill Book Company, Incorporated, New York, N. Y. $2.00. A standard reference book. Miller, W. G. Minerals and how they occur, a book for secondary schools, and prospectors. 1906, 252 pages. Copp, Clark, Ldmited, Toronto, Canada. Moses, A. J., and Parsons, C. L. Elements of mineralogy, crystallography, and blowpipe analysis from a practical standpoint. Edition 5, 1916, 631 pages. D. Van Nostrand Company, New York, N. Y. $3.00. A standard reference book including a description of all common or useful minerals, their formation and occurrences, the tests necessary for their identification, the recognition and measurement of their crystals, and their economic importance and uses in the arts. Oshorn, H. S. Prospector's field book and guide in the search for and the easy determination of ores and other useful minerals. Edition 8, 1910, 401 pages. H. C. Biard and Company, Philadelphia, Pa. $1.50. An excellent book, describ- ing many tests for determining minerals. Some of the tests are rather difficult to make satisfactorily. Packer, 0. H. Prospector's and miner's manual. 1913, 301 pages. Brown and Power Stationery Company, San Francisco, California. $3.00. An excellent book for prospectors and development engineers who have a technical training. Chapter 8 is a summary of the mineral districts in the United States that are particularly promising. Phillips, A. H. Mineralogy, an introduction to the theoretical and practical study of minerals. 1912, 699 pages. The Macmillan Company, New York, N. Y. $3.75. Pirsson. L. V. Rocks and rock minerals. 1910, 414 pages. John Wiley and Sons. New York, N. Y. $2.50. A standard textbook. The table for determining the common rocks (pages 404-408) is particularly valuable and useful. Schroder, F. C, Stone, R. W., and Sanford, Samuel. Useful minerals of the United States, 1917, 412 pages. United States Geological Survey Bulletin No. 624. Defines nearly 600 names of minerals and lists the occurrence of minerals by states in alphabetical order. Copy can be obtained by applying to Director, United States Geological Survey, Washington, D. C. Tarr, W. A. Tables for the determination of the common minerals and rocks. 1916. 28 pages. University Cooperative Store, Columbia, Mo. $0.40. The tables are excellent for laboratory reference but would be of value only to one understanding the terminology used. BOOKS ON ECONOMIC GEOLOGY. _To supplement the foregoing list, three standard works on economic geology might be mentioned, as follows : Emmos, W. H. The principles of economic geology. Edition 1, 1918, 606 pages. McGraw-Hill Book Company, Incorporated, New York, N. Y. $4.00. Material relating to metallic minerals is particularly valuable. Lindfjren, WaJdemar. Mineral deposits, 1913, 893 pages. McGraw-Hill Book Company, Incorporated, New York, N. Y. $5.00. One of the best treatises on economic geology. Ries, Heinrich. Economic geology. Edition 4, 1916, 856 pages. John Wiley and Sons, New York, N. Y. $4.00. Material relating to nonmetallic minerals is particularly valuable. 8— 24S4 11-lr CAIJFORNIA STATE MINING BLTREAU. BOOKS ON PROSPECTING. Underground Treasures, How and Where to Find Tliem. By James Orton. Plenry Carey Baird and Company, Philadelphia, 1901. Contains key for the ready determination of all the useful minerals within the United States ; directions for determining specimens ; descriptive list of use- ful minerals; prospecting for diamonds, gold, silver, copper, lead, and iron; assay of ores ; mineral springs ; discovery of gold in California ; discowry of silver in Nevada, and United States gold and silver statistics ; ore deposits. Hidden Mines, and how to find them. Contains the information called for by the ordinary business man, who is interested for business reasons only. By W. Thos. Newman. Buffalo, The M. Rogers Publishing Company, 1805. Contents include rock formations and ore deposits ; how to distinguish ores ; descriptions of native metals and ores ; other minerals of commercial value ; precious stones ; practical pointers. The Prospector's Manual, for the Discovery of Quartz and Placer Indications of Gold and Silver Mines, also a description of mineral bearing rocks ; indications of the mineral districts in all the New England states and the neighboring provinces ; the characteristics of California, Nevada and other mines ; simple methods of assaying gold and silver ores ; and the glossary of scientific and technical terms. By Wm. J. Schofield. W. J. Schofield and Company, pub- lishers, Boston, 1875. Prospector's Pocket Manual ; Where and How to Find Gold and Silvt^r Mines. By Henry J. Pomeroy. Davis and Freegard, St. Louis, 1881. Covers geology, mineralogy ; metallurgy ; advice to prospectors ; mining laws and rules, compiled for the Union Pacific Railway Company. Glossary of mining terms. Smith's Handbook of Valuable Minerals. By Frederick H. Smith, member A. I. M. E. Baltimore, 1895. Contents include bottom facts and bed rocks ; the coal measures ; oil and gas ; iron and manganese ores ; gold and silver ores ; copper and tin ores ; lead and zinc ; nickel, cobalt and chrome ; antimony, mercury, platinum ; gems and precious stones ; building and paving stones ; cements and clays ; salts and fertilizers ; mineral paints ; grits and spars ; other valuable minerals ; weights and measures ; companies and prices. Secrets of the Rocks ; or The Story of the Hills and the Gulches. A manual of Hints and Helps for the Prospector and Miner. By S. M. Frazier. Denver, Colo. Hall and Williams, 1905. Chemical elements and mineral compounds ; physical characteristics and classes of minerals ; rock fissures and vein formation, contact and other veins, lodes and wall rock ; locating gold bearing ledges, mineralogy and metallurgy in brief ; roasting minerals under examination ; surface disintegration of ore bodies ; nature's ore roasting process ; general chemical and special tests for minerals ; examination of mines and sampling ; placer mines and placer mining ; appliances for saving fine gold ; river mining ; tracing a quartz lode ; advice to prospectors ; rock constituents and mineral ores. The Prospector's Field Book and Guide in the Search for and Easy Determination of ores and other Useful Minerals. By Prof. II. S. Oshorn; Philadelphia, Henry Carey Baird and Company, 1910. Contains preliminary instruction in geology and mineralogy ; the blowpipe and its uses ; crystallography ; sui-veying ; analyses of ores ; special mineralogy ; tellurium, platinum, silver; copper; lead and tin; zinc, iron, molybdenum, titanium, uranium, vanadium ; mercury ; bismuth, nickel, cobalt, cadmium, alumi- num, antimony, manganese ; various useful minerals, gems and precious stones, I)etroleum, ozocerite, asphalt, peat ; prospecting by means of electricity, weights and measures, standard values of gold in different countries, power for mills, boring, glossary of mining terms. The A B C of Mining, a Handbook for Pi-ospectors. By Charles A. Bramble. Rand, McNally and Company, Chicago and New York, 1898. The contents include chapters on prospecting, how to test for minerals, blow- pipe tests; economic ores and minerals; mining; camp life; surveying; floating a company ; medical hints ; dynamite ; atomic weights ; miscellaneous information. COMMERCIAL MINERALS OF CALIFORNLV. 115 Prospectiujr for Gold and Silver. By Arthur Lakes. Scrauton, Pa., the Colliery Engineer Company, 1895. Contains articles on prospecting — preparation and outfit for work; the pros- pector's historical geology ; paleontology or study of fossils ; lithology or study of rocks : mineralogy ; ore deposits — theories regarding their origin ; various forms of ore deposits ; relation of veins to eruptive forces ; gold placers ; deep leads : mining regions, showing examples of ore deposits ; ore deposits in sedimentary rocks ; examining and sampling mining properties, prospects or mines ; salting mines ; prospector's tools ; elements of mining law relating to prospecting. Prospecting, Locating and Valuing Mines. By R. H. Stretch. Published by the Scientific Publishing Company, New York and London, 1899. Contents cover chapters on mistakes in mining ; what constitutes a mine ; rock forming minerals and rocks ; physical character of mineral deix)sits ; origin of veins : filling of mineral veins ; influence of rocks on vein filling, mineral deposits other than veins ; prospecting ; making locations ; patents to mining ground : early development of mines ; ores ; useful earthy minerals ; coal ; gold gravel deposits ; water and its measurement ; artesian wells ; useful tables ; reference books. The Gold Tracer ; a Practical Guide for Prospectors and Miners. By Joseph M. Clark. Published 1899 at Portland Ore., by John Talbot. How to become a successful pi"ospector or miner ; ore bodies ; placer gold ; how to pan ; tracing : to uncover hidden veins ; post holes ; gold ; a test of ores — gold test : tests for silver, copper, platinum, nickel, the blowpipe ; gold in pyrites : chlorination ; outfit for prospector ; values of different metals ; composition of minerals ; history of quartz mining ; diagrams. The Miner's Geology and Prosi>ector's Guide for Mining Students, Miners, Pros- pectors and Explorers. By Geo. A. C order; London and New York, Spon and Chamberlain, 1907. Geology and its allied sciences — geognosy, lithology, petrology and paleon- tology ; properties of minerals ; mechanical, organic, igneous and metamori^hic rocks, divisions of the earth's crust ; composition of soil ; alternation of strata : fossil remains; non-fragmental rocks, crystalline and glassy rocks, compound rocks, granites ; sedimentary and stratified rocks ; secondary or mesozoic, tertiary, etc. Mineral prospecting, weights and measures ; gold ; where gold is found, value of the ore. methods of recovery, tools, blasting ; weight, specific gravity, and values of ores in lode, minerals and rocks ; the blowpipe ; water power, air, windmills : surveying, assay of gold ; useful tables, notes and formulae ; systems of crystallization ; paleontology. Prospecting for Gold and Silver. Instruction paper issued by the International Cx)rrespondence Schools, Scranton, Pa. 1898. Preliminary education and preparation; use of fossils; prospector's outfit ; prosi>ecting placer deposits ; locating placer claims ; United States practice-area and shape of placers, knowledge of mineral value ; recording ; staking ; pros- pecting lodes or veins ; float ; sampling the outcrop ; locating lode claims ; tunnel sites; mill sites; geology of ore deposits; rock forming minerals; regions most favorable for ore deposits; examples of prospecting regions; prospector's tools. Valuable Minerals, How to Find and Know Them. By Arthur J. Burdick. Published by the Gateway Publishing Company, Beaumont, California, 1916. Contents 'nelude chapters on how to find minerals ; how to test rocks and ores ; gems and how to find them ; gold, silver, copper, lead, coal ; other valuable minerals; use of the blowpipe. PUBLICATIONS. 117 PUBLICATIONS OF THE CALIFORNIA STATE MINING BUREAU. Publications of this Bureau will be sent on receipt of the requisite amount. Only stamps, coin or money orders will be accepted in payment. The prices, noted, include delivery charges to all parts of the United States. Money orders should be made payable to the State Mining Bureau. Personal checks will not be accepted. REPORTS. Asterisk (*) indicates the publication is out of print. ♦Report I. Henry G. Hanks. 1880. ♦Report II. Henry G. Hanks. 1882. ♦Report III. Henry G. Hanks. 1883. ♦Report IV. Henry G. Hanks. 1884. ♦Report V. Henry G. Hanks. 1885. ♦Report VI. Part 1. Henry G. Hanks. 1886. ♦Report VI. Part 2. Wm. Irelan, Jr. 1886. ♦Report VII. Wm. Irelan, Jr. 1887. ♦Report VIII. Wm. Irelan, Jr. 1888. ♦Report IX. Wm. Irelan, Jr. 1889. ♦Report X. Wm. Irelan, Jr. 1890. Price Report XL Wm. Irelan, Jr. 1892. (First biennial) $1.00 ♦Report XII. J. J. Crawford. 1894. (Second biennial) ♦Report XIII. J. J. Crawford. 1896. (Third biennial) Chapters of State Mineralogist's Report, Biennial period, 1913-1914. Fletcher Hamilton : Mines and Mineral Resources of Imperial and San Diego Counties. — F. J. H. Merrill. 1914 .35 ♦Mines and Mineral Resources, Amador, Calaveras and Tuolumne Counties — W. B. Tucker, 1915 Mines and Mineral Resources, Colusa, Glenn, Lake, Marin, Napa, Solano, Sonoma and Yolo Counties — Walter W. Bradley. 1915 .50 Mines and Mineral Resources, Del Norte, Humboldt and Mendocino Counties — F. L. Lowell. 1915 .25 Mines and Mineral Resources, Fresno, Kern, Kings, Madera, Mariposa, Mer- ced, San Joaquin and Stanislaus Counties — Walter W. Bradley, G. C. Brown, P. L. Lowell and R. P. McLaughlin. 1915 .50 Mines and Mineral Resources, Shasta, Siskiyou and Trinity Counties — G. C. Brown. 1915 .50 Report XIV. Fletcher Hamilton, 1915, Biennial period 1913-1914. (The above county chapters combined in a single volume) . 2.00 Chapters of State Mineralogist's Report, Biennial Period, 1915-1916, Fletcher Hamilton : Mines and Mineral Resources, Alpine, Inyo and Mono Counties, with geological map — Arthur S. Eakle, Emile Huguenin, R. P. McLaughlin, Clarence A. Waring. 1917 1.25 Same as above, without geological map .65 Mines and Mineral Resources. Butte, Lassen, Modoc, Sutter and Tehama Coun- ties — W. Burling Tucker, Clarence A. Waring. 1917 .50 Mines and Mineral Resources, El Dorado, Placer, Sacramento and Yuba Coun- ties — W. Burling Tucker, Clarence A. Waring. 1917 .65 Mines and Mineral Resources, Los Angeles, Orange and Riverside Counties — Frederick J. H. Merrill. 1917 .50 Mines and Mineral Resources, Monterey, San Benito, San Luis Obispo, Santa Barbara and Ventura Counties — Walter W. Bradley, Emile Huguenin, C. A. Logan, Clarence A. Waring. 1917 .65 Mines and Mineral Resources, San Bernardino and Tulare Counties — H. C. Cloudman, Emile Huguenin, F. J. H. Merrill, W. Burling Tucker 1917 .65 Report XV. Fletcher Hamilton, 1918, Biennial period, 1915-1916. (The above county chapters combined in a single volume) 3.75 Chapters of the State Mineralogist's Report, Biennial Period 1917-1918. Fletcher Hamilton : Mines and Mineral Resources of Nevada County — Errol MacBoyle. 1918 — .75 Mines and Mineral Resources of Plumas County — Errol MacBoyle. 1918. — ,50 Mines and Mineral Resources of Sierra County — Errol MacBoyle. 1918. .50 BULLETINS. ♦Bulletin 1. Dessicated Human Remains. — Winslow Anderson. 1888 ♦Bulletin 2. Methods of Mine Timbering. — W. H. Storms. 1894 ♦Bulletin 3. Gas and Petroleum Yielding Formations of the Central Valley of California. — W. L. Watts. 1894 ♦Bulletin 4. Catalogue of California Fossils (Parts 2, 3, 4 and 5). — J. G. Cooper. 1894 ♦Bulletin 5. The Cyanide Process: Its Practical Application and Economical Results.— A. Scheidel. 1894 118 CALIFORNIA STATE .AIIXIXG BUREAU. PUBLICATIONS OF THE CALIFORNIA STATE MINING BUREAU— Continued Asterisk (*) indicates the publication is out of print. Bulletin 6. Califorrxia Gold Mill Practices.— E. B. Preston. 1895 •Bulletin 7. Mineral Production of California, by Counties, 1894. — Ciias. G. Yale. (Tabulated sheet) ♦Bulletin 8. Mineral Production of California, by Counties, 1895. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 9. Mine Drainage, Pumps, etc. — Hans C. Behr. 1896 ♦Bulletin 10. A Bibliography Relating to the Geology, Palaeontology, and Mineral Resources of California. — A. W. Vogdes. 1896 ♦Bulletin 11. Oil and Gas Yielding Formations of Los Angeles, Ventura and Santa Barbara Counties. — W. L. Watts. 1896 ♦Bulletin 12. Mineral Production of California, by Counties, 1896. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 13. Mineral Production of California, by Counties, 1897. — Chas. G. YqIo r TS-blll^tGd. sllGGt ^ — ♦Bulletin 14. Mineral Production of California, by Counties, 1898. — Chas.~GT Yale. (Tabulated sheet) Bulletin 15. Map of Oil City Oil Fields, Fresno County. — J. H. Means ♦Bulletin 16. The Genesis of Petroleum and Asphaltum in California. — A. S. Cooper. 1899 ♦Bulletin 17. Mineral Production of California, by Counties, 1899. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 18. The Mother Lode Region of California. — W. H. Storms. 1900 ♦Bulletin 19. Oil and Gas Yielding Formations of California. — W. L. Watts. 1900 ♦Bulletin 20. Synopsis of General Report of State Mining Bureau. — ^W. L. Watts. 1900 ♦Bulletin 21. Mineral Production of California, by Counties, 1900. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 22. Mineral Production of California for Fourteen Years. — Chas. G. Yale. 1900. (Tabulated sheet) Bulletin Reconnaissance of the Colorado Desert Mining District. — Stephen Bowers. 1901 Bulletin 23. The Copper Resources of California. — P. C. DuBois, F. M. Ander- son, J. H. Tibbits, and G. A. Tweedy. 1902 ♦Bulletin 24. The Saline Deposits of California. — G. E. Bailey. 1902 ♦Bulletin 25. Mineral Production of California, by Counties, 1901. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 26. Mineral Production of California for Fifteen Years. — Chas. G. Yale. 1901. (Tabulated sheet) ♦Bulletin 27. The Quicksilver Resources of California. — Wm. Forstner. 1903— ♦Bulletin 28. Mineral Production of California, by Counties, 1902. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 29. Mineral Production of California for Sixteen Years. — Chas. G. Yale. 1902. (Tabulated sheet). ♦Bulletin 30. A Bibliography of Geology, Palaeontology, and Mineral Resources of California. — A. W. Vogdes. 1903 ♦Bulletin 31. Chemical Analyses of California Petroleum. — H. N. Cooper. 1903. (Tabulated sheet) ♦Bulletin 32. Production and Use of Petroleum in California. — P. W. Prutzman. 1904 ♦Bulletin 33. Mineral Production of California, by Counties, 1903. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 34. Mineral Production of California for Seventeen Years. — Chas. G. Yale. 1903. (Tabulated Sheet) ♦Bulletin 35. Mines and Minerals of California, for 1903. — Chas. G. Yale. 1904. (Statistical) ♦Bulletin 36. Gold Dredging in California.— J. E. Doolittle. 1905 Bulletin 37. Gems, Jewelers' Materials, and Ornamental Stones of California. — George F. Kunz. 1905: First edition (without colored plates) ♦Second edition (with colored plates) ♦Bulletin 38. The Structural and Industrial Materials of California. — Wm. Forstner, T. C. Hopkins, C. Naramore, L. H. Eddy. 1906 ♦Bulletin 39. Mineral Production of California, by Counties, 1904. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 40. Mineral Production of California for Eighteen Years. — Chas. G. Yale. 1904. (Tabulated sheet) ♦Bulletin 41. Mines and Minerals of California, for 1904. — Chas. G. Yale. (Statistical) ♦Bulletin 42. Mineral Production of California, by Counties. 1905. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 43. Mineral Production of California for Nineteen Years. — Chas. G. Yale. 1905. (Tabulated sheet) ♦Bulletin 44. Mines and Minerals of California, for 1905. — Chas. G. Yale. (Statistical) ♦Bulletin 45. Auriferous Black Sands of California. — J. A. Edman. 1907 Bulletin 46. General Index to Publications of the State Mining Bureau. — Com- piled by Chas. G. Yale. 1907 ♦Bulletin 47. Mineral Production of California, by Counties, 1906. — Chas. G. Yale. (Tabulated sheet) ♦Bulletin 48. Mineral Production of California for Twenty Years. — Chas. G. Yale. 1906. (Tabulated sheet) Price $0.5( $0 PUBLICATIONS. 119 Ictin 49. letin 50. letln 51. letln 52. LIGATIONS OF THE CALIFORNIA STATE MINING BUREAU— Continued. Asterisk (*) indicates the publication Is out of print. Price. Mines and Minerals of California, for 1906. — Chas. G. Yale. (Statistical) The Copper Resources of California. — A. Hausmann, J. Krutt- schnitt, Jr., W. E. Thome, J. A. Edman. 1908 $1.00 Mineral Production of California, by Counties, 1907. — D. H. Walker. (Tabulated sheet) Mineral Production of California for Twenty-one Years. — D. H. Walker. 1907. (Tabulated sheet) ineral Production of California for 1907, with County Maps — D.H.Walker. 1908. (Statistical) ineral Production of California, by Counties, 1908. — D. H. Walker. (Tabulated sheet) Mineral Production of California for Twenty-two years. — D. H. Walker. 1908. (Tabulated sheet) Mineral Production for 1908, County Maps, and Mining Laws of California. — D.H.Walker. 1909. (Statistical) Gold Dredging in California. — W, B. Winston, Charles Janin. 1910 Mineral Production of California, by Counties, 1909. — D. H. Walker. (Tabulated sheet) Mineral Production of California for Twenty-three Years. — D. H. Walker. 1909. (Tabulated sheet) Mineral Production for 1909, County Maps, and Mining Laws of California. — D. H. Walker. 1910. (Statistical) Mineral Production of California, by Counties, for 1910. — D. H. Walker. (Tabulated sheet) Mineral Production of California for Twenty-four Years. — D. H. Walker. 1910. (Tabulated sheet) Petroleum in Southern California. — P. W. Prutzman. 1912 .75 Mineral Production for 1911. — E. S. Boalich, Statistician. 1912__ Mineral Production for 1912. — E. S. Boalich. 1913 Mining Laws (United States and California). 1914 Minerals of California. — A. S. Eakle. 1914 Mineral Production for 1913. — E. S. Boalich. 1914 Petroleum Industry of California with Folio of Maps (18x22 in.) — R. P. McLaughlin and C. A. Waring. 1914 2.00 Mineral Production for 1914, with Mining Law Appendix. 1915. California Mineral Production for 1915, with Mining Law Appen- dix and Maps. — Walter W. Bradley. 1916 Geologic Formations of California. — James Perrln Smith. 1917. (For Map, see below) .25 Report of Operations of Department of Petroleum and Gas for 1915-1916. — R. P. McLaughlin. 1917 California Mineral Production for 1916, with County Maps. — Walter W. Bradley. 1917 Mining Laws, United States and California. 1917 Manganese and Chromium in California. — ^Walter W. Bradley, Emile Huguenin, C. A. Logan, W. Burling Tucker, C. A. Waring. 1918 .50 Catalogue of the Publications of the California State Mining Bureau, 1880-1917. — E. S. Boalich. 1918 Quicksilver Resources of California. — Walter W. Bradley. 1918— 1.50 Magnesite in California. (In press) Tungsten, Molybdenum and Vanadium, in California. (In prep- aration) Copper Resources of Foothill Belt, California. (In preparation)— Second Annual Report of the State Oil and Gas Supervisor, 1916-1917. — R. P. McLaughlin. 1918 ^ California Mineral Production for 1917, with County Maps. — Walter W. Bradley. 1918 Third Annual Report of the State Oil and Gas Supervisor, 1917- 1918. — R. P. McLaughlin. 1919 Platinum Resources of California -50 California Mineral Production for 1919, with County Map. Walter W. Bradley. 1919 Commercial Minerals of California. — ^W. O. Castello. (In press) California Mineral Production for 1919, with County Maps — Walter W. Bradley. 1920 PRELIMINARY REPORTS. illetin 63. Uetin 64. Illetin 65. Illelin 66. Illetin 67. Illetin 68. lletin 69. Illetin 70. lletin 71. lletin 72. Illetin 73. lletin 74. lletin 77. lletin 78. lletin 79. ;ietin 80. lletin 81. lletin 82. letin 87 letin 88 ^liminary Report No. 1. Notes on Damage by Water in California Oil Fields, Dec, 1913. By R. P. McLaughlin liminary Report No. 2. Notes on Damage by Water in California Oil Fields, Mar., 1914. By R. P. McLaughlin iliminary Report No. 3. Manganese and Chromium, 1917. By E. S. Boalich /liminary Report No. 3. Manganese and Chromium. By E. S. Boalich. / (Second edition) ^liminary Report No. 4. Tungsten, Molybdenum and Vanadium, 1918. By f E. S. Boalich and W. O. Castello 'f^liminary Report No. 5. Antimony, Graphite, Nickel. Potash, Strontium, Tin, 1918. By E. S. Boalich and W. O. Castello Preliminary Report No. 6. Review of Mining in California during 1919 'reliminary Report No. 7. Clay Industry of California 120 CALIFORNIA STATE MINING BUREAU. PUBLICATIONS OF THE CALIFORNIA STATE MINING BUREAU— Continued. REGISTERS OF MINES WITH MAPS. Asterisk (*) indicates tlie publication is out of print. Price Amador County $.25 Butte County .25 ♦Calaveras County *E1 Dorado County *Inyo County ♦Kern County ♦Lake County ♦Mariposa County ♦Nevada County ♦Placer County ♦Plumas County ♦San Bernardino County . ♦San Diego County Santa Barbara County .25 ♦Shasta County ♦Sierra County ♦Siskiyou County ♦Trinity County ♦Tuolumne County Yuba County .25 Register of Oil Wells (with map), Los Angeles City .35 OTHER MAPS. ♦California, Showing Mineral Deposits (50x60 in.) — mounted Forest Reserves in California — Mounted .50 Unmounted .30 ♦Mineral and Relief Map of California El Dorado County, Showing Boundaries of National Forests .20 Madera County, Showing Boundaries of National Forests .20 Placer County, Showing Boundaries of National B'orests .20 Shasta County, Showing Boundaries of National Forests .20 Sierra County, Showing Boundaries of National Forests .20 Siskiyou County, Showing Boundaries of National Forests .20 ♦Trinity County, Showing Boundaries of National Forests Tuolumne County, Showing Boundaries of National Forests .20 ♦Mother Lode Region Desert Region of Southern California .10 Minaret Region, Madera County .20 Copper Deposits in California .05 Calaveras County .25 Lake County .25 Tuolumne County ' ',25 Geological Map of California (mounted) — 50x60 inches 2.50 Geological Map of Inyo County .60 OIL FIELDS MAPS. The following maps of the oil fields of the state have been completed and placed on sale : The prices of the maps are 75 cents per copy, with the exception, of the Sargent oil map, which is 50 cents. These prices include postage. Map No. 1 — Sargent, Santa Clara County. Map No. 2 — Santa Maria, including Cat Caiion and Los Alamos. Map No. 3 — Santa Maria, including Casmalia and Lompoc. Map No. 4 — ^Whittier-Fullertoh, including Olinda, Brea Caflon, Puente Hills, East Coyote, and Richfield. Map No. 5 — Whittier-F'ullerton, including Whittier, West Coyote, and Montebello. Map No. 6 — Salt Lake, Los Angeles County. Map No. 7 — Sunset and San Emidio, Kern County. Map No. 8 — South Midway and Buena Vista Hills, Kern County. Map No. 9 — North Midway and McKittrick, Kern County. Map No. 10 — Belridge and McKittrick Front, Kern County. Map No. 11 — Lost Hills and North Belridge, Kern County. Map No. 12 — Devils Den, Kern County. Map No. 13 — Kern River, Kern County. Map No. 14 — Coalinga, Fresno County. Map No. 15 — Elk Hills. Kern County. Map No. 16 — Ventura-Ojai, Ventura County. Map No. 17 — Santa Paula-Sespe Oil Fields, Ventura County. Map No. 18 — (In preparation). Map No. 19 — Arroyo Grande, San Luis Obispo County. DETERMINATION OF MINERAL SAMPLES. Samples (limited to three at one time) of any mineral found in the state may be sent to the Bureau for identification, and the same will be classified free of charge. No samples will be determined if received from points outside the state. It must be understood that no assays or quantitative determinations will be made. Samples should be in lump form if possible, and marked plainly with name of sender on out- side of package, etc. No samples will be received unless delivery charges are prepaid. A letter should accompany sample, giving locality where mineral was found and the nature of the Information desired. INDEX. Page Aluminum 12 Amphibole 17 Anglesite 54 Antimony 14 Apatite — 73 Appendix 105 Arsenic 16 Arsenopyrite 16 Asbestos : 17 Asphalt 19 Azurite 34 Barite 30 Barium 20 Barytas 20 Bauxite — 12 Bibliography 112-115 On Economic Geology 113 On Mineralogy 112 On Prospecting 114 Biotite 61 Bismite 23 Bismuth 22 Bismuthinite 23 Bismutite 23 Bituminous Rock 19 Benitoite 44 'Blister Copper' 35 Borax 24 Bornite 34 Brass 33 Braunite . 58 Brick 31 Bronze 33 Cadmium _. . 25 Calamine 102 Carnotite 100 Cassiterite 96 Celestite 91 Cement 1 26, 27 Cerussite 54 Chalcedony 44 Chalcocite ; 34 Chalcopyrite 34 Chalk 28 Chromite 29 Chromium 28 Chrysotile 17 Cinnabar 81 Clay 31 Coal 32 Colemanite 24 Copper 33 Corundum 36 Crushed Rock 89 Cryolite : 40, 41 Cuprite 34 ^2484 (121) 122 INDEX. Page Descloizite 100 Diamond 44 Diatomaceous Earth 28, 49 Dolomite 37 Economic Geology, Bibliography on 113 Emerald 44 Emery 36 Everett, Washington, production of arsenic at _- 16 Feldspar 38 Ferberite — 98 Fluorite — 40 Fluorspar 40 Franklinite 102 Fuller's Earth __— 41 Galena 5n Galenite 5:! Gems 42 Glauberite __— 89 Gold 44 Granite 45 Graphite . 46 Greenockite 26 Grinding-Mill Pebbles 89 Gypsum 4^ Halite S;] Hanksite 89 Hematite 51, 62 Hiibnerite 9S Information Bureau, General 9^ Infusorial Earth 28, 49| Iron : 50| Kunzite -- 441 Laboratory 9; Lead 53; Lepidolite 61 Library . 9 Lime 27 Limestone 27 Limonite 51, 62 Lithia __— 60 Lithopone 20 Malachite 34. Manganese 57 Manganite _ — 58 Magnieslte 55 Magnetite — 52 Marble 59 Marcasite 80 Mercury 8 ] Metacinnabarite 82 Mica 60 Mlorocline oii Millerite 69 Mineralogy, Bibliography on 15 2 Mineral Paint 62 Miscellaneous Stone 8 9 INDEX. 123 Page Molybdenite 65 Molybdenum 63 Monazite 66, 73 Muscovite 61 Native Copper 34 Iron 51 Natron 88 Natural Gas 67 Niccolite -- 69 Nickel 68 Niter 70 Nitrates 70 Nitrocalcite 71 Opal 44 Orpiment — 16 Orthoclase — — 39 Patronite — _ 100 Paving Blocks 89 Petroleum — _ — 72 Petroleum and Gas, Department of 10 Phlogopite — 61 Phosphate Rock 72 Platinum 74 Potash 76 Potassium 76 Pottery 31 Preface 9 Prospecting, Books on 114 Publications 9 Psilomelane 57 Pumice 78 Pyrite 80 Pyrites 79 Pyrolusite _ 58 Pyrrhotite , 69, 80 Quartz — 84 Quicksilver 81 Realgar -- 16 Rock Salt . 83 Roscoelite 100 Ruby 37, 44 Salt 82 Saltpeter 70 Sand 84 Sandstone : 84 Sapphire 37, 44 Scheelite 98 Silica 84 Silver 86 Slate 86 Smithsonite 102 Soapstone — 94 Soda ST Soda Niter — To Sodium Ss Sodium Carbonate — : J^^^ Sphalerite 102 124 INDEX. t .^ Page Spodumene — 44 Stannite ^ 96 State Mining Bureau Activities — . 9-11 General Information Bureau Liaboratory !» Library 1» Museum — 10 Petroleum and Gas, Department of 10 Publications , 9 Statistical Department 10 War activities : — 11 Statistical Department _— 10 Stibnite ] 4 Strontianite 9] Strontium !tO Sulphur 92 Sulphuric Acid 81 Talc . 94 Tetrahedrite 34 Thenardite SS Tile 31 Tin 95 Topaz 44 Tourmaline 44 Trona SS; Tungsten 9 7 Ulexite 2 1 Vanadinite 100 Vanadium 99 Volcanic ash — 78 Tuff 79 War Activities of State Mining Bureau 11 Willemite 102 Witherite 21 Wolframite 9 8 Wulfenite 54, 64 Zinc 101 Zincite 102 CALIFORNIA STATE MIINING BUREAT FERRY BUILDING, SAN FRANCISCO FLETCHER HAMILTON State Mineralogist ? j San Francisco] BULLETIN No. 88 [July, 1920 California Mineral Production for 1919 WITH COUNTY M.A.FS CALIFORNIA STATS PKINTING OFFICE SACBAMENTO 19 2