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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 
 <nid called 'pig iron.' The 'pig iron' generally contains from 3% 
 lo 4% carbon, 0.5% to 3% silica and small amounts of sulphur and 
 {)hosphorus. It is later refined and converted into the various grades 
 (if iron and steel. 
 
 LEAD. 
 
 Missouri is the largest lead producer among the states, followed by 
 Utah, Colorado, Oklahoma, Arizona, California and ^Montana. 
 
 Industrial application and uses. 
 
 Lead is used extensively for war munitions — bullets, shells, car- 
 tridges, shrapnel, bombs, etc. For these purposes it is generally 
 alloyed with a little arsenic or antimony. It is used to a great extent 
 for pipes of various sizes and shapes because of its resistance to 
 corrosion, and because it can be easily bent and cut and can be made 
 into any length desired by soldering. Lead pipe is extensively used 
 for carrying copper Avires both overhead and underground. Many 
 alloys as solder, type metal, pewter, brass and bronze, contain varying 
 amounts of this metal. It is made into sheets and used for roofs, to 
 line sinks, cells in electrolytic processes and in metallurgical apparatus. 
 So-called red lead (an oxide, PbgO^) and wliite lead (basic lead 
 carbonate) are extensively used in paint manufacture. Litharge 
 (PbO) is used as a flux in assaying. 
 
 Properties and ores. 
 
 Native or metallic lead (Pb) is a soft, heavy lead-gray metal, bright 
 metallic luster when freshly cut, but usually tarnished to dull or sub- 
 metallic. It is very malleable and melts easily. Hardness 1.5, specific 
 gravity 11.37. Seldom found in nature in this form. Galena, with 
 its alteration products, cervissite and anglesite, are the principal ores. 
 
 Galena or galenite (PbS). Lead sulphide. Color lead-gray, streak 
 dark gray, metallic luster, perfect cubic cleavage, hardness 2.5, specific 
 gravity 7.3-7.6. Contains 86.6% lead and 13.4% sulphur. Occurs 
 in cubes, also massive, lamellar or foliated. Common in gold, silver 
 and copper districts. 
 
54 CALIFORNIA STATE MINING BUREAU. 
 
 Cerussite (PbCOg) lead carbonate. Color gray, cream or brown, 
 vitreous to adamantine luster, hardness 3.0-3.5, specific gravity 
 6.46-6.57. Generally occurs massive, and is a common alteration 
 product of galena, and is often a rich silver ore. . 
 
 Anglesite (PbSO^) lead sulphate. Colorless, wlciite yellow, gray or 
 brown, adamantine luster, hardness 2.5-3.0, specific gravity 6.35. 
 Occurs massive or in prismatic crystals. Common oxidization product 
 of galena, but usually found in small amounts. 
 
 Wulfenite (PbMoO^) molybdate of lead. Color orange-yellow to 
 bright red, adamantine luster, hardness 3.0-4.5, specific gravity 
 6.0-7.0. Occurs massive or in thin tabular crystals. Also described 
 under molybdenum. 
 
 Distribution. 
 
 Lead produced in California comes principally from Inyo County, 
 which produced 91% of the total in 1918. Other principal producing 
 counties in order are San Bernardino, Kern and Shasta. It is usually 
 found in gold, silver and copper districts, and is commonly associated 
 with the sulphides of zinc, copper, iron and with barite, fluorite and 
 calcite. 
 
 Tests. 
 
 Lead compounds when fused on charcoal with sodium carbonate, 
 before the reducing flame of the blowpipe, give metallic globules of 
 lead and a coating of oxide which is sulphur yellow near the assay 
 and bluish white a short distance away. Galena, when roasted in the 
 open tube gives off sulphur dioxide; it is oxidized by concentrated 
 nitric acid, with usually the separation of lead sulphate and also some 
 sulphur. Cerussite is soluble in warm dilute nitric acid Avith effer- 
 vescence (evolution of carbon dioxide gas). In the closed tube, when 
 heated it decrepitates (breaks up) and is changed to lead oxide which 
 is dark yellow when hot. 
 
 Metallurgy. 
 
 Lead is derived from its ores by methods of roasting and reduction 
 in both blast and reverberatory furnaces. 
 
 Galena containing gold, silver and other valuable metals, also the 
 oxidized ores, (oxides and carborates) are treated in blast furnace. 
 The charge consists of coke, ore and fluxes. The lead is separated 
 from the ore and collected as 'base bullion.' The sulphur forms 
 with the copper and iron a 'matte,' while the remaining bases unite 
 with the silica to form 'slag.' If there are not basses enough in the 
 original ore to form a suitable slag, fluxes must be added. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 55 
 
 The 'base bullion' is refined for the production of pure lead, and 
 the recovery of the gold, silver and other precious metals. The lead 
 copper 'matte'- is resmelted and refined. High grade non-siliceous 
 ores containing little silver, are best treated by roasting and reduction 
 in the reverberatory furnace. This process may be divided into two 
 stages, namely oxidation and reduction. The ore is ground fine, spread 
 out evenly over the hearth, and heated for several hours, at compara- 
 tively loAv temperature (500° to 600° Centigrade). The charge is 
 frequently raked over to expose new surface to the action of the heat 
 and air. Only part of the galena is changed to lead sulphate, the 
 remainder being unaltered. The temperature is then raised to about 
 700° Centigrade, when the oxide and sulphate formed in the first 
 stage, re-act with the unchanged galena, producing metallic lead, which 
 flows down the inclined hearth and collects in a basin, while the 
 sulphur dioxide gas passes off through the flue. Slaked lime is often 
 added to stiffen the charge and to make it spongy. 
 
 The process of oxidation and reduction is repeated several times, 
 before the greater part of the lead is obtained from the charge, eacli 
 successive operation being shorter and the temperature higher. To- 
 wards the end, coal or charcoal is added for further reduction. The 
 slag residue may still contain considerable lead, and this is treated 
 in the blast furnace. The refining of the bullion is accomplished by 
 electrolysis. 
 
 MAGNESITE. 
 
 The demand for magnesite greatly increased during the war, because 
 of its extensive use for refactory linings in all kinds of smelting 
 furnaces, and because of its numerous other applications which made 
 it indirectly of great value as a war mineral. As a refractory it 
 is a substitute for chromite. It thus released much of the latter 
 mineral for use in the manufacture of steel. 
 
 For several years previous to the war the United States produced 
 only approximately 6 or 7% of the total amount of the magnesite 
 consumed, the imports coming chiefly from Austria and Greece. The 
 home production was forced to supply not only the tonnage of imports 
 Avhich were almost entirely cut off, but also the increased demand at 
 home. The country turned to California for this supply because for 
 many years previous to 1916 this state was the sole producer of mag- 
 nesite. The results are shown by the fact that in 1917 the production 
 was fKV; of the consumption. In that year the State of Washington 
 showed considerable output. 
 
56 CALIFORNIA STATE MINING BUREAU. 
 
 Industrial application and uses. 
 
 The principal uses are : refractory linings for steel furnaces, copper 
 reverberatories and converters, bullion and other metallurg'ical fur- 
 naces, sanitary flooring in office buildings, hospitals, ship decks, rail- 
 road cars, kitchens, etc. It is also used in the manufacture of paint, 
 paper and medicines. 
 
 The best refractory material is made by 'dead burning' the mag- 
 nesite, i.e., driving off practically all of the carbon dioxide (CO.) 
 leaving magnesia (MgO). For cement purposes it is left caustic, that 
 is, 5% to 107o of the COg is retained. 
 
 Magnesium powder is used in fireworks and in flash light powder. 
 
 Properties and ores. 
 
 Magnesium, although never found free in nature, is the basis for 
 many common minerals. It is a silvery white metal, metallic luster, 
 very light (specific gravity 1.75), tenacious and ductile. When hot 
 it can be drawn into wire or ribbon, the latter being a common com- 
 mercial form. It melts easily and burns with a dazzling white light, 
 producing dense white clouds of magnesium oxide. 
 
 Magnesite (MgCOg) magnesium carbonate, is the common ore of 
 magnesium. Contains 47.6% MgO and 52.4% COg. It is snow white 
 to brown in color. Vitreous to silky luster. Hardness 3.5-4.5. Grav- 
 ity 3.0-3.2. Quite brittle. Generally compact, massive with conchoi- 
 dal fracture. Usually associated with magnesian rocks, especially ser- 
 pentine, from which it is an alteration product. Sometimes associated 
 with limestone and gypsum. 
 
 Occurrence. 
 
 Magnesite is a very common mineral in California because of the 
 great areas of serpentine in the Coast Range and the Sierra Nevada. 
 Much of it is very high grade, some deposits yielding above 95% 
 MgCOo. The Porterville district in Tulare County is one of the 
 most important in the state. In Sonoma, Santa Clara and Napa 
 counties are several large deposits. Considerable tonnage has also 
 been produced in Kern, Riverside, Fresno and Mendocino counties. 
 
 Tests. 
 
 Magnesite is not acted upon by cold dilute hydrochloric acid (HCl), 
 but dissolves readily with effervescence in hot acid. If the solution 
 is made strongly alkaline with ammonia, and sodium phosphate added, 
 a white crystalline precipitate will be formed. Before testing, how- 
 ever, it must be ascertained wliether other substances are present which 
 would tend to form a precipitate. A good procedure is as follows: 
 
COMMERCIAL MINERALS OF CALIFORNIA. 57 
 
 Dissolve a very small portion of the mineral in a small quantity 
 of boilins: hydrochloric acid, add a drop or two of nitric acid and 
 then water, and again heat to boiling. Add ammonia in excess, and 
 filter if there is a precipitate. To the filtrate add ammonium carbonate 
 or oxalate and again filter. Then add sodium phosphate for the 
 precipitate described above. 
 
 Preparation. 
 
 The ore is sometimes shipped raw, in which case it goes to the 
 steel mills, but more often it is calcined at the mines, in rotary or 
 vertical shaft kilns, and the calcined product sold to the plastic trade. 
 The rotary kiln is the most modern and is coming into general use. 
 
 MANGANESE. 
 
 In 1917 the production of manganese in the United States was 
 approximately one-third of tte amount consumed. The recent in- 
 crease in the consumption of this material in the manufacture of 
 steel has been supplied almost entirely by augmented home produc- 
 tion, as the imports for 1917 were but little more than during the 
 previous year. The imports come mainly from Brazil. California 
 has played an important part in this regard, as may be seen from the 
 following figures: The production for 1915 was 4013 tons, valued 
 at $49,098 ; for 1916 it was 13,404 tons, valued at $274,601 ; for 1917 
 it was 15,515, valued at $396,659; and for 1918 it was 26,075 tons, 
 valued at $979,235. In 1917 the total approximate production of 
 the United States was 113,734 tons. 
 
 The silica content should not be over 8%, although higher percent- 
 ages are allowed with penalty. 
 
 Industrial application and uses. 
 
 Most of the manganese consumed in the United States goes into the 
 manufacture of ferro-manganese, which is used in removing certain 
 impurities from steel ; it is also used in the manufacture of very hard, 
 high grade steel, which is in great demand at the present time. It 
 is used to a smaller extent in the manufacture of glass, electric dry 
 batteries, paint, pottery, tile and brick. 
 
 Properties and ores. 
 
 The metal manganese (Mn) is not found free in nature, but we 
 recognize it through its compounds or ores. Three of these are of 
 distinct commercial value, the most important of which are the oxides, 
 i. e., manganese in combination with oxygen. The first, manganese 
 dioxide (MnO2.MnoO3.II2O), called Psilomelane, is the most important. 
 
58 CALIFORNIA STATE MINING BUREAU. 
 
 It is iron black or greenish black in color, and gives a dull black streak. 
 It is very heavy (specific gravity -4.4) and quite hard (hardness 
 -5.0-6.0). When broken it presents a shelly appearance, resembling 
 that of broken glass, and has a sub-metallic luster. Its characteristic 
 occurrence is in irregular masses with smooth surfaces in jasper in 
 the Coast Ranges and in slates, shales and igneous rocks of the Sierra 
 Nevada. The other important oxide, Pyrolusite (MnOs) is iron 
 black in color, v/ith a black streak; 63.2% Mn. 36.8% 0. It is much 
 softer than the ore mentioned above (hardness 2.0-2.5) and slightly 
 heavier (specific gravity -4.8). It has a sub-metallic luster and when 
 broken appears splintery. Generally occurs massive, although some- 
 times in coatings or as a powder. 
 
 Other less important oxides are Manganite and Braunite, both of 
 which are heavy black minerals, with black or brownish streak, aii<[ 
 more or less metallic luster. Manganite generally occurs in lar^c 
 porous masses with columnar structure in jasper or altered rocks. 
 Braunite occurs in either massive or crystalline form. 
 
 Besides the oxides mentioned above, and quite in contrast to them, 
 is the carbonate, Rhodochrosite (MnC03). This mineral is rose red 
 in color, with pearly or vitreous (glassy) luster. Often found in 
 gold and silver regions associated with the veins. May occur in masses 
 or in small crystals. 
 
 Distribution. 
 
 The majority of the manganese deposits of which the Mining Bureau : 
 has record, are located in the Coast Range. They are widely dis- 
 tributed from Siskiyou County, southerly through Trinity, Humboldt, 
 Tehama, Mendocino, Glenn, Lake, Sonoma and Napa counties. 
 
 Further south there is a prominent belt including the easterly 
 portions of Alameda, Santa Clara and San Benito counties and the 
 westerly portion of San Joaquin, Stanislaus and Merced counties. 
 There are several deposits in the northwestern part of San Luis Obispo 
 County. In the foothills of the Sierra Nevada are several deposits, \ 
 principally in Plumas, Butte, Nevada, Amador and Tuolumne coun- 
 ties. A few properties are located in San Bernardino, Riverside and 
 Kern counties. 
 
 Tests. 
 
 Easy field tests for manganese ores may be made as follows : 
 Make a borax bead by dipping a loop of fine platinum wire into ^ 
 l)o\vdered borax, and heating until reduced to a clear glass. A very 
 .small piece or a little of the powder of the mineral will color this 
 bead a deep amethyst when hot and reddish brown when cold. When 
 fused with soda, manganese ores give an opaque green bead. This 
 
COMMERCIAL MINERALS OF CALIFORNIA. 59 
 
 lest gives best results if a little potassium nitrate (KNO3) is added 
 Tor thorough oxidization. Pyrolusite, when heated in the closed tube, 
 liives off oxygen gas. Its softness is also one means of distinguishing 
 it. Ehodochrosite, when treated with dilute hydrochloric acid, effer- 
 vesces and gives off carbon dioxide gas (COo). 
 
 Metallurgy. 
 
 Ores containing more than 40% manganese and generally less than 
 15% silica are smelted to ferro-manganese w^hich contains 70-80% 
 manganese, 12-20% iron and 6-7% carbon. 
 
 Lower grade ores are smelted to ' spiegeleisen, ' a ferro-mangane.se 
 which, in most cases, contains from 15 to 20% manganese, 70-75% 
 iron and -1-5% carbon. 
 
 Manganiferous zinc residuum is also smelted to spiegeleiseu. 
 
 In the open hearth process of making manganese steel, the ferro- 
 manganese is used, while in the Bessemer process, spiegeleiseu is used. 
 
 For use in the manufacture of dry batteries very high grade ore 
 is required. 
 
 MARBLE. 
 
 There are many beautiful marbles in this state, which are of durable 
 quality, but the production has decreased in recent j^ears due to the 
 fact that the foreign marbles and that from eastern states and Alaska 
 can often be shipped here by water cheaper than the local product 
 can be marketed. 
 
 The principal producing states are Vermont, Pennsylvania, Mass- 
 achusetts, Maryland, Georgia and Kentucky. No recent data for 
 the total domestic production is available, but in 1915 the production 
 in the United States was valued at almost $7,000,000. 
 
 The Italian marble is the most famous in the world, and is pro- 
 duced in the greatest quantities. Other principal producers are 
 France. Greece, Spain and Mexico. 
 
 Industrial application and uses. 
 
 Marble is used extensively as a building material, principally in 
 interior finishings of a highly decorative nature, such as courts and 
 corridors in public and office buildings, hotels, apartment liouses and 
 private residences. The great varieties in color and the high polish 
 which it takes, make it possible to produce beautiful decorative effects. 
 Great quantities are used for statuary, monuments, etc. 
 
 Properties. 
 
 Marble may be pure calcite (CaCOJ, may be magnesian or dolomitic, 
 or may be pure dolomite (CaMgCOg). Much of the marble in this 
 
60 CALIFORNIA STATE MINING BUREAU. 
 
 state is dolomitic. It has a highly crystalline or granular texture and 
 may be almost any color from pure white to reddish, due to natural 
 coloring materials such as iron, manganese, etc. Hardnes.s, 3.0, spec- 
 ific gravity 2.25-2.75. Easily cut into various shapes or slabs of large 
 size and takes a high, beautiful polish. 
 
 Distribution. 
 
 The marble produced in California comes from quarries in Inyo 
 and Tuolumne counties. It also occurs in Amador, Butte, Kern, San 
 Bernardino, Santa Cruz, Siskiyou, Solano and Tulare counties. 
 
 Tests. 
 
 All marbles effervesce freely i. e., give off carbon dioxide gas, when 
 treated with dilute h^^drochloric acid. The acid may have to be 
 warmed slightly before action will start. Most marbles are also easily 
 distinguished by color softness and general appearance. 
 
 MICA AND LITHIA. 
 
 Mica became of some importance as a war mineral through its use as 
 windows in gas masks, armored cars, protective goggles, and similar 
 uses where it was substituted for glass, and as an insulating material 
 in electrical apparatus. 
 
 There has been no marked effect upon the production during the 
 war, but the price increased considerably. The total value of mica 
 produced in the United States in 1917 was $757,346, about 93% of 
 this value being in sheet mica. This was the highest value of record, 
 althougli the quantity produced w^as smaller than for several years. 
 
 North Carolina was the largest producer, with New Hampshire 
 second. Small amounts were produced in Virginia, South Dakota, 
 Georgia and Alabama. The domestic production for the past several 
 years has averaged in the neighborhood of 38% of the total consump- 
 tion. In 1917 the imports were valued at $1,429,004 and came mainly 
 from Canada, England, India, Argentine and Brazil. There was a 
 small production in California in 1902, 1903 and 1904, but there has 
 been none reported since then. 
 
 Lithia was produced in San Diego County for several years from 
 1899 to 1905, but there was no production from the latter date until 
 1915, when 91 tons were mined, valued at $1365. In 1918 there were 
 4111 tons produced valued at $73,998. The latter was lepidolite from 
 San Diego County. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 61 
 
 Industrial application and uses. 
 
 The industrial value of mica lies in Its great resistance to heat and 
 acids, its perfect, easy cleavage, its transparency and its insulating 
 properties. Sheet mica finds its greatest use in the electrical industry 
 in the construction of dynamos, electric light sockets, spark plugs, 
 insulators, fuse boxes and telephones. It is also used in place of 
 glass for windows, lamp chimneys, automobile curtain windows, stove 
 fronts, portholes, peepholes in furnaces, etc. Ground mica is used in 
 fancy paints and wall paper, to which it gives luster and brightness; 
 in the manufacture of ornamental tile, insulating and fire-proofing 
 compounds and paints, pipe and boiler coverings, patent roofing mate- 
 rial, gunpowder, blasting powder, etc., as a lubricant when mixed 
 with oil, in making rubber goods, and in calico printing. 
 
 Lithia is used in the preparation of lithia salts, the metal lithium, 
 mineral water, fireworks, and signal rockets. 
 
 Properties and ores. 
 
 The micas embrace a number of silicates of potassium, aluminum, 
 sodium, and magnesium. Their characteristic occurrence is in thin 
 elastic scales and plates. Of the many varieties the most important 
 from a commercial standpoint is muscovite, but phlogopite and biotite 
 are sometimes of value. 
 
 Muscovite (HKAlSiO^). Hydrous silicate of potassium and 
 aluminum. Colorless, gray, brown, or pale green, vitreous or pearly 
 luster, perfect basal cleavage, soft (hardness 2.0-2.5, and light (spe- 
 cific gravity 2.7-3.0). Occurs in scales, hexagonal plates or sheets. 
 Very common in granite, syenites, schists and gneisses. 
 
 Phlogopite. Properties similar to above except in color, which is 
 pearl gray, yellowish brown or green. 
 
 Biotite. Properties same as above, except that color is dark green 
 or black and luster is more resplendent. 
 
 Lepidolite. Lithia mica. Silicate of lithium, potassium, aluminum 
 and fluorine. Color lilac, lavender, violet or pink, commonly in scaly 
 masses with pearly luster, associated with tourmaline. Perfect basal 
 cleavage, hardness 2.5-4.0, specific gravity 2.8-2.9. Less common than 
 the other micas. 
 
 Distribution. 
 
 Although mica occurs in almost all granitic and gneissoid rocks, it 
 is not commonly of sufficient size to be of commercial value. It is :i: 
 pegmatite and coarsely f eldspathic veins, and in the case of phlogopite, 
 in calcareous rocks associated with eruptive pyroxenites, that it is of 
 valuable size. 
 
62 CALIFORNIA STATE MINING BUREAU. 
 
 Tests. 
 
 The micas are easily distinguished by their perfect cleavage, pearly 
 luster and color. Lepidolite has distinguishing colors and responds 
 to the test for lithia, i. e., gives a lilic-red color when moistened with 
 hydrochloric acid and held on a platinum wire in the flame. It is 
 easily fusible to a white or gray globule, and gives acid Avater when 
 intensely ignited in the closed tube. Muscovite is scarcely acted upon 
 by boiling concentrated sulphuric acid, while biotite and phlogopite, 
 when similarly treated are decomposed, and the acid becomes turbid. 
 
 Preparation. 
 
 There is a great waste in preparing the sheet mica for the market. 
 The first step in the process is to cut the sheets to certain patterns, 
 which most closely fit the sizes of the natural plates. They are cut 
 with large shears, one leg of which is firmly fastened on a large table. 
 Then the plates are 'cleaned' by holding them up to the light of 
 a window, and the outside pieces, if they contain flaws, are stripped 
 off. This process is continued until a clear flawless sheet remains. 
 One hundred pounds of black mica, yields on an average 15 or 20 
 pounds of the finished product. The waste mica is ground and used 
 for the various purposes mentioned above. 
 
 MINERAL PAINT. 
 
 The iron oxides, hematite and limonite, are the most valuable of the 
 state's mineral pigments. The jasper produced is of value on account 
 of the color, which is probably due to oxides of iron and manganese. 
 
 Industrial application and uses. 
 
 Many natural substances, as described below^ are used either di- 
 rectly or indirectly in the manufacture of paints and coloring mater- 
 ials of all kinds. The product may be marketed as ready mixed paint, 
 as a powder or as a solid material, as white lead. Ground slates and 
 shales are used as fillers in oil cloth and linoleum manufacture, as well 
 as in paints. 
 
 Properties and ores. 
 
 The three ores of iron, hematite, limonite and siderite, are the basis 
 from which the metallic paints and mortar colors are derived. 
 Limonite, containing more or less clay, forms the yellow ochre of 
 commerce. Metallic paints are made by grinding the natural oxides 
 or by roasting the carbonate, siderite. Mortar colors are used for 
 tinting mortar, cement and concrete. 
 
 The above, together with umber, sienna and ground slate and shale, 
 comprise the natural mineral pigments. 
 
COMMERCIAL MINERALS OF CALIFORNLV, 63 
 
 Umber consists of iron and aluminum silicates with varying amounts 
 of manganese oxides. The raw material is drab in color, but after 
 calcining it is reddish brown and is called 'burnt umber.' Sienna 
 is essentially the same composition as umber, but with less manganese 
 oxide and is a lighter color. The calcined product is called 'burnt 
 sienna. ' 
 
 Pigments which are manufactured directly from ore.s are zinc oxide, 
 leaded zinc oxide, white lead and blue lead. 
 
 Pigments which are entirely chemically manufactured are red lead, 
 A^^netian red, lithopone, litharge and orange mineral. 
 
 Distribution. 
 
 In 1917, mineral paint was produced in Calaveras, Colusa. San 
 Bernardino and Stanislaus counties. That from Colusa and San Ber- 
 nardino was hematite and jasper, while that from Calaveras and Stan- 
 islaus Avas yellow ochre, the latter product being of excellent quality 
 and the equal of any that is imported. Deposits of mineral paint 
 are also located in Kern, Kings, Lake, Los Angeles, Nevada, Riverside 
 and Sonoma counties. 
 
 Tests. 
 
 Deposits of material suitable for mineral paints must be judged as 
 
 to their commercial quality by persons experienced in those lines. 
 
 Tests for and descriptions of the iron ores were given under that 
 
 heading. 
 
 MOLYBDENUM. 
 
 Molybdenum, although regarded as one of the rarer metals, has 
 recently become of increased value on account of its use in the steel 
 industry. The United States at present appears to be the world's 
 largest producer, and exports considerable metal and concentrates. 
 Arizona and Colorado are the principal producers. In 1917 the domes- 
 tie production amounted to 175 tons of metal, valued at $^350,000. 
 Xo production in California was reported up to 1915. In that year 
 a small tonnage was mined in Plumas County, but not marketed. In 
 1916 there were 8 'tons of picked concentrate produced in Inyo and 
 Plumas County, valued at $9,945. In 1917 the production was 228 
 tons of ore, valued at $6,014. There was only one producer in 1918, 
 a flotation plant on the Boulder Creek mine in Shasta County. 
 
 The price has increased from an average of 50^ per pound in 1914 
 to 75^ per pound in 1916, and $1.00 per pound in 1917. Occasionally 
 quotations have been as high as $2.00 per pound of 90% MoS,>. 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 coa<st or bays at San 
 Francisco, Los Angeles and San Diego. Formerly considerable table 
 salt consumed in California was obtained from eastern states, but for 
 the past few years California refineries have not only supplied our 
 own markets, but have exported some to other states and to Australia. 
 
 Industrial application and uses. 
 
 Besides the well known household uses of seasoning and preserving 
 there are other important industries in w^hich salt is essential, such 
 as fish and meat packing and canning, dairy industry, curing and 
 preserving hides, manufacture of chemicals, soap, glass and sodium 
 salts, and in bleaching many different materials. 
 
 Properties and ores. 
 
 Salt occurs in nature in two distinct ways — as rock salt in beds 
 associated with sedimentary deposits, and in natural brines. 
 
 Halite, Rock Salt (NaCl). Sodium chloride. Pure white, to 
 slightly reddish or yellowish in color, perfect cubic cleavage, vitreous 
 luster, distinctly salty taste, hardness 2.5, specific gravity 2.13. Occurs 
 in large masses or groups of cubic crystals, or as granular deposits. 
 
 The sea water, which contains about 3% salt, is an inexhaustible 
 source from which salt is obtained by evaporation. 
 
 Distribution. 
 
 In San Bernardino County there are deposits of rock salt which 
 are worked by means of quarrying and steam shovels. There are 13 
 refining plants operating in Alameda County, three in San Mateo, 
 two in San Diego and one each in Inyo, Kern, Los Angeles, Mono, 
 Monterey, Solano, and San Bernardino counties. 
 
 Tests. 
 
 Salt is easily told by the taste and appearance. Also gives the 
 intense yellow color to the flame due to sodium. The solution when 
 made acid with nitric acid gives with silver nitrate a precipitate of 
 silver chloride. 
 
64: CALIFORNIA STATE MINING BUREAU. 
 
 Preparation. 
 
 Salt is derived principally from sea water by solar evaporation. 
 Fire is seldom used for evaporating, because of the cost of fuel. The 
 water is admitted at high tide into large ponds covering many acres, 
 and when it has become sufficiently concentrated by evaporation, it 
 is pumped into smaller vats, which, in some cases, are provided with 
 wooden floors. The process of evaporation is here continued to dry- 
 ness, the salt covering the bottom of the vats from six inches to one 
 foot in depth. It is then gathered, hauled to the refinery and stacked. 
 
 The crude salt is washed in a concentrated solution, and then re- 
 dissolved in pure fresh water. The brine goes to settling tanks, where 
 it remains for about twenty-four hours. After leaving the settling 
 tanks, it goes through a system of sterilization and filtration, which 
 removes all impurities and is then evaporated in large pans. The 
 product is pure crystallized salt. This is dried, ground, and graded 
 for the various uses. 
 
 When the brines are pumped from natural salt deposits, they are 
 treated much as above, but the solutions are often of such concentration 
 to warrant evaporation by fire. 
 
 SANDSTONE. 
 
 The production of sandstone has decreased greatly in the last few 
 years, due to the increase in the use of reinforced concrete, and* 
 granite, in building construction. 
 
 There is a great amount of high grade sandstone in California, the 
 best known quarries being those in Colusa County. These have been 
 closed during the last few years because of the production elsewhere 
 of a lighter colored material. 
 
 Many large buildings in San Francisco and other cities are con- 
 structed of Colusa sandstone, among the most noteworthy in San 
 Francisco being the Ferry Building, Saint Francis Hotel, Flood Build- 
 ing, Humboldt Savings Bank, Monadnock Building, Kohl Building 
 and Merchants National Bank. 
 
 SILICA, SAND AND QUARTZ. 
 
 Silica, as here used, includes that utilized for all purposes except 
 for concrete, mortar and other building purposes, and for gem stones. 
 In the glass and pottery industries there is an enormous demand for 
 good quality silica. The greatest demand comes from the large manu- 
 facturing centers. The most important producing states are Maryland, 
 California, Pennsylvania, Illinois, Massachusetts, Michigan, New Jer- 
 sey and Tennessee. 
 
COMMERCIAL MINERALS OP CALIFORNIA. 85 
 
 Industrial application and uses. 
 
 Silica is used principally in the manufacture of glass, pottery, 
 
 aints, scouring soaps, and abrasive and polishing materials. Much 
 
 sand is used as a building material in concrete, mortar, foundry work, 
 
 etc., but the material used in this way is not included in the figures 
 
 given here. 
 
 Silica is the basis of all glass manufacture, and in the pottery 
 industry- it is used in the body of the ware to reduce shrinkage, and 
 also in the glazes. The pigments in some paints contain as much as 
 one-third finely ground silica. The finely ground material is better 
 for this purpose than the fine natural sand, because of its angularity 
 rnd better adhering qualities. It is also better for soaps, scouring 
 material and polishing powders. Crushed quartz of various size is 
 used in making sandpaper, sand belts and material for sand-blast 
 apparatus. 
 
 Much silica is used as a flux in copper smelting, and other metal- 
 lurgical processes, assaying, etc., and in the manufacture of ferro- 
 silicon and other alloys in the electric furnace. 
 
 Properties. 
 
 Silica (SiOo) occurs in deposits of commercial importance in many 
 different forms, such as sand, sandstone, vein quartz, quartzite, flint, 
 tripolite, etc. In all its various forms quartz makes up about three- 
 fifths of the solid crust of the earth, and is therefore very common. 
 
 Quartz occurs in many varieties either crystalline or compact mas- 
 sive. Large masses of crj'stals in hexagonal prisms and pyramids are 
 frequently found. The color varies from pure white to yellow, brown, 
 red-brown, amethyst, rose, etc., vitreous luster, hardness 7.0, specific 
 gravity 2.65, prominent conchoidal fracture. Veins, ledges, seams 
 and masses of white quartz are common in volcanic and metaraorphic 
 areas and much of it is gold bearing. 
 
 Sand is composed principally of fine particles of quartz, and sand- 
 stone is formed by the natural cementing of these particles. 
 
 Flint is a hard, dark amorphous form of silica. 
 
 Distribution. 
 
 Silica was produced commercially in 1918 from 13 properties in 
 Amador, El Dorado, Monterey, Placer, Riverside, and Tulare counties. 
 
 Both quartz and sand are so abundant that it is only a question 
 of locating deposits of sufficient purity which can be econojnicallj^ 
 marketed. 
 
86 CALIFORNIA STATE MINING BUREAU. 
 
 Tests. 
 
 Quartz or silica is so common and well known that it is not difficult 
 to detect. The easiest test, and one which illustrates the principle 
 of ^lass manufacture is made by fusing before the blowpipe a little 
 of the powdered mineral with an equal volume of sodium carbonate. 
 This may also be done by making the mixture into a paste with water 
 and heating on a loop of platinum wire or on a piece of clean char- 
 coal. A clear glass bead should result. 
 
 SILVER. 
 
 The principal producing silver states in the order of the value of 
 their production in 1916 were: Montana, Nevada, Utah, Idaho, Colo- 
 rado, Arizona and California. 
 
 The rise in the price of silver in the last few years has been phenom- 
 enal. From an average of 50.7^ per ounce in 1915 it increased to 
 65.8^ in 1916, 82.4^ in 1917, 96.7^ in 1918, and 111.12 in 1919. In 
 September 1917, the price reached the highest point in 40 years, the 
 quotations being around $1 per ounce. 
 
 The production of silver in California comes principally from the 
 copper, lead, zinc and gold mines. The greatest output is from Inyo 
 and Shasta counties. In Inyo County the production comes from the 
 extensive silver-lead deposits of that district and in 1918 the silver 
 output from this county Avas valued at $441,548. In Shasta County 
 the silver is derived from the large output of copper, and in 1918 
 the production of silver was valued at $420,410. Other important 
 producing counties are Calaveras, San Bernardino, Plumas, Nevada 
 and Amador. 
 
 Total production in California in 1918 was valued at $1,427,861. 
 
 SLATE. 
 
 Pennsylvania is by far the largest producer of slate, followed by 
 Vermont, Virginia, Maryland, New York, Maine, New Jersey, Tennes- 
 see, Utah and California. 
 
 The only production in California since 1910 was in 1915 when 1000 
 squares were produced, valued at $5,000. Considerable slate is ex- 
 ported to Canada, South America, and the West Indies. 
 
 Industrial application and uses. 
 
 Slate is used for roofing material, architectural purposes, various 
 structural, electrical and sanitary purposes, school slates and black- 
 board material. The architectural slate must be of unusual thick- 
 ness — from three-sixteenths of an inch up to two inches. The demand 
 
COMMERCIAL MINERALS OF CALIFORNIA. 87 
 
 for roofing slate has decreased in the last few years, because of many 
 patent roofing materials recently put on the market. Various grades 
 of material for structural and sanitary purposes are known as will 
 stock. Other uses for slate are for tombstones, billiard table tops, 
 ground slate for roofing material and a few minor uses. 
 
 Properties and ores. 
 
 Slate is a fine-grained metamorphosed sedimentary rock, with a 
 close crystalline texture. The most striking characteristic and the one 
 which gives it its economic value is the prominent cleavage. It may 
 be split or broken into very thin, smooth slabs. It is generally bluish- 
 uray, but is often highly colored by various oxides. It is soft enough to 
 be easily scratched with a knife, yet so dense that it rings when struck 
 with a hammer. 
 
 In composition the slates are composed of about 56% silica (SiOg), 
 249; aluminum oxide (AloOg), and varying amounts generally from 
 2 to 5% of the oxides of magnesium, calcium, iron, potassium and 
 sodium. 
 
 Distribution. 
 
 Slat'^ was first produced in California in 1889, and the production 
 was '-ontinuous up to and including 1910. This production came from 
 large deposits in El Dorado, Calaveras, and Mariposa counties. The 
 property of the Sierra Slate Corporation, fo-rmerly the Eureka Slate 
 Company, in El Dorado County was operated on an extensive scale. 
 The product is of such good quality that it has been accepted by the 
 government as suitable for federal work. 
 
 Tests. 
 
 The physical properties, especially the prominent easy cleavage, are 
 the determining factor in securing a body of commercial value. It also 
 must bo fine-grained, and the cleavage plates must be of considerable 
 
 size. 
 
 SODA. 
 
 The war has greatl}- stimulated the soda industry in the United 
 States, because of discontinued imports, and in order to supply foreign 
 countries where production has been cut down. Sodium products have 
 replaced those of potassium in many industries. 
 
 Industrial application and uses. 
 
 The principal uses for the soda materials are in the manufacture 
 of glass, soap and paper, in sugar refining, in the preparation of 
 caustic soda or sodium hydroxide (NaOH), and recently to some ex- 
 
88 CALIFORNIA STATE MINING BUREAU. 
 
 tent in tanning, match making and the manufacture of cyanide for 
 extracting gold and silver from their ores. 
 
 Properties and ores. 
 
 Sodium is a silver white metal, so soft that it may be easily cut 
 with a knife or moulded with the fingers. It floats upon water (spe- 
 cific gravity 0.98) and decomposes it at ordinary temperature, liberating 
 hydrogen. It burns at low temperature with a brilliant yellow flame, 
 tarnishes easily in moist air, the surface becoming covered with a 
 brownish coating. 
 
 Sodium carbonate (NasCOg) is prepared by two well-known pro- 
 cesses: the Leblanc and the Solvay. In the Leblanc process sodium 
 chloride or common salt is first changed into sodium sulphate by 
 sulphuric acid. 
 
 2 NaCl + H.SO, = HNaSO, + HCl + NaCl 
 HNaSO, + NaCl = Na^SO^ + HCl 
 
 The impure product (Na2S04) is called 'salt cake,' and hydro- 
 chloric acid is a by-product. The salt cake is changed into sodium 
 carbonate by heating with coal and limestone. 
 
 Na2S04 + 2C = Na^S + 200^ 
 
 Na^S + CaCOg = Na^COg -f CaS 
 
 The sodium carbonate is separated from the impure product by 
 dissolving in water. After evaporation and ignition the product is 
 *soda ash,' and from this is produced 'sal soda' or 'washing soda' 
 (NasCOg.lOH^O). 
 
 In the Solvay process a cold concentrated solution of salt is satu- 
 rated, first with ammonia gas and then with carbon dioxide gas. 
 
 Sodium bicarbonate (HNaCOg) is a by-product qf the Solvay 
 process. It is a white powder, less soluble in water than the normal 
 carbonate, and when heated or mixed with an acid or an acid salt, gives 
 up its carbon dioxide. This led to its use as 'cooking or baking soda.' 
 Baking powder is a mixture of soda and cream of tartar. 
 
 Trona (Na2CO3.HNACO3.2HoO) Natural hydrous bicarbonate of 
 sodium. Found only in dry protected places as crystals and finely 
 fibrous coatings. Color white, vitreous luster, alkaline taste, hard- 
 ness 2.5-3.0, specific gravity 2.1. 
 
 Natron (NagCOg.lOHgO) Hydrous carbonate of sodium. Color 
 white, vitreous luster, hardness 1.0-1.5, specific gravity 1.42-1.46, 
 alkaline taste. Occurs mixed with trona. 
 
 Thenardite (Na2S04) Sodium sulphate. Color white, vitreous lus- 
 ter, hardness 2.68-3.0, specific gravity 2.68-2.69. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 89 
 
 Glauhente (Na2S04.CaS04) Sulphate of sodium and calcium. 
 Color white, gray or yellor, vitreous luster, hardness 2.5-3.0, specific 
 gravit}" 2.7-2.85, perfect basal cleavage. 
 
 Hanksite (4Na2S04.Na2C03) Double soda salt. Color white, vitre- 
 ous luster, hardness 3.0-3.5, specific gravity 2.56, saline taste. 
 
 Distribution. 
 
 The commercial production of soda ash and sodium bicarbonate in 
 California in 1918 came from three plants located at Owens Lake in 
 Inyo County, and comprised about 93% of the total value of soda 
 products marketed. 
 
 Natural sulphate came from the Carrizo Plains, San Luis Obispo 
 County, a natural carbonate from Dorris, Siskiyou County, and sul- 
 phate from the natural brines of Searles Lake, San Bernardino County. 
 
 Tests. 
 
 All sodium minerals give the characteristic .vellow flame test. The 
 carbonates natron and trona effervesce when treated with acids, and 
 their aqueous solutions give an alkaline reaction with turmeric paper 
 i. e., turn it reddish-brown. Natron dissolves in its water of crystal- 
 lization when gently heated in the closed tube and trona gives water 
 and carbon dioxide when similarly treated. 
 
 MISCELLANEOUS STONE. 
 
 Under the heading of miscellaneous stone are included crushed 
 rock of all kinds for macadam, ballast, rubble, etc., stone paving blocks, 
 sand, gravel and pebbles for grinding mills. Thus grouped together, 
 these materials form one of the most important industries of the state, 
 amounting in 19-16 to a value of $4,171,519 and in 1917 to $3,634,767. 
 In both years they ranked sixth in value of California mineral products. 
 
 Paving blocks have decreased in use, owing to the need for smoother 
 roadbeds for motor vehicle traffic. It is difficult to make estimates 
 of this material, because no definite record is kept of a great deal of 
 rock which is used by almost every county in building and repairing 
 roads. 
 
 Grinding-mill pebbles were produced for the first time in California 
 in 1915. These come from the gold dredger tailings in Sacramento 
 County, from beaches in San Diego County, and from river gravels 
 in Fresno County. 
 
 Industrial application and uses. 
 
 Crushed rock of various sizes is used in almost all concrete and 
 reinforced concrete construction, in macadam and oil macadam for 
 
90 CAT.IFORNIA STATE MINING BUREAU. 
 
 roadways, and for ballast ou railways. Sand and gravel are also used 
 to a great extent in this class of work. Sand is used in mortars and 
 cements. Grinding pebbles are used in mills of various kinds for 
 grinding and pulverizing ore in mining operations. 
 
 Properties. 
 
 The hardest rocks such as basalt, diabase, flint or felsite are required 
 for grinding-mill pebbles, and these must be well rounded and smooth. 
 Paving blocks produced are basalt, andesite, granite, and trachyte. 
 Rock crushed for concrete may be any of these varieties depending 
 on the locality. 
 
 Distribution. * 
 
 Los Angeles County leads all others in the value of output of mis- 
 cellaneous stone, followed in order by Alameda, Contra Costa, Sac- 
 ramento, Marin, Sonoma, and Fresno. Nearly every county in the 
 state produces this material to some extent. 
 
 STRONTIUM. 
 
 Until the last two or three years the domestic strontium deposits 
 had remained undeveloped and search for new deposits had not been 
 made. This was due to the fact that foreign ore from England, Prus- 
 sia and Sicily could be obtained at a lower cost than home ore could bo 
 produced and marketed. The known deposits of commercial import- 
 ance are in the South and West, and prior to 1916 the chemical plants 
 manufacturing strontium salts were on or near the North Atlantic 
 seaboard. Freight rates therefore were the determining factor. Many 
 other difficulties attached to the commercial exploitation, such as limited 
 market, small value, etc., tended to keep the productio"n down to prac- 
 tically "a negligible quantity. However, with the advent of the war 
 which brought not only an increased demand but a discontinuance of 
 the imports, an impetus was given to domestic production. 
 
 Industrial application and uses. 
 
 Strontium nitrate is used in the manufacture of fire works and 
 signal rockets of all kinds on account of the brilliant crimson color 
 it produces. The demand for it in this industry has greatly increased 
 with the war. The hydroxide is used in the sugar refining industry. 
 Before the war Germany used about 100,000 tons of strontium 
 hydroxide annually in the beet sugar industry alone. Great develop- 
 ments can reasonably be expected along this line in this country. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 91 
 
 Properties and ores. 
 
 Strontium is an uncommon metallic element. It never occurs free, 
 but forms many compounds that are quite rare in nature. The sul- 
 phate 'celestite' and the carbonate ' strontianite ' are the only com- 
 mercial ores. 
 
 Celestite (SrSOJ Strontium sulphate. Contains 56.4% (SrO) 
 and 43.6% (SO3). Color white to pale blue, sometimes reddish, vit- 
 reous or pearly luster, nearly perfect cleavage in Hiree directions at 
 right angles to one another. It is heavy (specific gravity 3.0) and 
 soft enough to be scratched with a knife (hardness 3.0-3.5). Resembles 
 barite (BaSO^). Occurs as a massive, finely crystalline rock which 
 closely resembles crystalline limestone, or in long, slender tabular or 
 fibrous crA'stals. 
 
 Strontianite (SrCO^) Strontium carbonate. Contains 70.3% (SrO) 
 and 29.7% (CO2). Color white, pale green or yellow, vitreous or 
 resinous luster, heavy (specific gravity 3.7) and easily scratched by a 
 knife (hardness 3.5-4.0). It may be either transparent or translucent, 
 is quite brittle and has prismatic cleavage. Usually found in needle- 
 shaped crystals. It is the most valuable ore of strontium, but is rarely 
 found in bodies of commercial size. 
 
 Distribution. 
 
 The production in California has been from celestite deposits in 
 Imperial County and from strontianite deposits near Barstow in San 
 Bernardino County. Celestite 'also occurs in the Avawatz Mountains 
 in San Bernardino County and in Inyo County. Besides California, 
 there has been production of the sulphate in Arizona, Washington, 
 New York, Texas, Ohio, Utah and Michigan. 
 
 Strontium ores are found in beds of sandstone, limestone, gypsimi, 
 rock salt and clay. They are closely associated with the sediments 
 formed by the drying up of the lakes of the Tertiary period. 
 
 Tests. 
 
 The principal tests for strontium are the crimson flame test and 
 the alkaline reaction after heating. For the color test a hot, non- 
 luminous (blue) flame, such as given by an alcohol lamp or a blow- 
 pipe i-s required. The mineral is pulverized and heated with hydro- 
 chloric acid. The solution is evaporated until it is fairly thick. A 
 loop of clean platinum wire is dipped into the concentrated solution 
 and heated in the blue flame. If strontium is present a brilliant 
 crimson color will appear, which must be distinguished from the yellow 
 color oiven by sodium and barium. Both the sulphate and the car- 
 l)()iiatc when heated before the blowpipe and placed on moistened 
 
92 CALIFORNIA STATE MINING BUREAU. 
 
 turmeric paper, will turn it red (alkaline reaction). The carbonate 
 when "heated before the blowpipe, swells and spouts, while the sulphate 
 flies to pieces (decrepitates), but the latter will fuse at low tempera- 
 tures. 
 
 Preparation. 
 
 Strontium nitrate is prepared by treating the natural carbonate, 
 strontianite, with .hot nitric acid (HNO3). 
 
 The hydroxide, Sr(0H)2 may be prepared in a great number of 
 ways from either celestite or strontianite. In one process, strontianite 
 is treated with superheated steam, while another method is to roast 
 celestite with coal and brown iron ore. 
 
 Metallic strontium is best obtained by electrolysis of the fused 
 chloride. 
 
 SULPHUR. 
 
 There is a great demand for sulphur in the manufacture of sul- 
 phuric acid, both for agricultural and war munition purposes. It is 
 estimated that 463,36-i long tons were used for this purpose alone in 
 1917. This was more than 100,000 tons greater than the entire domes- 
 tic consumption for all purposes in 1914, notwithstanding the fact that 
 under ordinary conditions about 150,000 tons are used annually in 
 the manufacture of paper. In 1914 the total production in the United 
 States was 327,634 long tons, and the imports for the some year were 
 26,135 long tons. In the last three years 99% of the domestic produc- 
 tion came from two companies and for this reason no figures are pub- 
 lished. However, in 1917 the production had increased sufficiently 
 to supply all demands and leave 152,821 loDg tons for export. The 
 imports were less than 1000 tons. 
 
 There has been no commercial production in California since 1865- 
 1868, in which period a total of 941 tons valued at $53,500 was shipped 
 from the famous Sulphur Bank Mine in Lake County. 
 
 Industrial application and uses. 
 
 Under normal conditions the greatest amount of sulphur is used 
 in the manufacture of paper and the preparation of cliemicaLs. One- 
 eighth of a ton is used for each ton of sulphite pulp manufactured. 
 In the last few years however, greater quantities have been used in the 
 manufacture of sulphuric acid. Never before has so much sulphuric 
 acid been used in this country. This is due to its application in so 
 many industries, many of which had a direct bearing upon the war 
 plan. Notable among these are: the manufacture of almost every 
 
COMMERCIAL MINERALS OP CALIFORNIA. 93 
 
 other kind of acid, purification and refining of many oils, making 
 sulphate of soda (salt cake), soap, glass, fertilizers, etc. 
 
 Considerable quantities of native sulphur are also used in the manu- 
 facture of explosives, fireworks and matches and for medicinal pur- 
 poses and as a germicide. 
 
 Properties and ores. 
 
 Native sulphur (S) is yellow in color, brittle, resinous luster, soft 
 (hardness 1.5-.5) and light (specific gravity 2.0). Has a conchoidal 
 or uneven fracture. Burns with a blue flame and gives off strong 
 odor of sulphur dioxide. Occurs in beautiful crystals or in massive 
 stalactitic and spherodial forms. Often impure through the presence 
 of clay and bituminous matter. 
 
 Distribution. 
 
 Sulphur both free and combined is abundant and widely distributed. 
 Native sulphur is found usually in regions of volcanic activity, geysers, 
 hot springs, etc., where it is formed through the oxidation of hydrogen 
 sulphide (HgS). There are also beds associated with gypsum, which 
 were no doubt formed by the reduction of the gypsum (CaSO^) with 
 limestone and sulphur. 
 
 Two companies: the Union Sulphur Company in Louisiana and the 
 Freeport Sulphur Company in Texas, furnished 99% of all the sulphur 
 produced in the United States in 1917. Small amounts have been pro- 
 duced in Nevada, Utah, Idaho, Wyoming and Alaska. 
 
 There is at present no commercial output of this mineral in Cali- 
 fornia, although it has been found to some extent in many counties, 
 namely : Colusa, Imperial, Inyo, Kern, Lake, Mariposa, San Bernardino 
 and Sonoma. During the years 1865-1868 sulphur was produced at 
 the Sulphur Bank mine in Lake County. Later, the mine became 
 valuable for its quicksilver. 
 
 Tests. 
 
 When once seen the mineral is readily recognized by its physical 
 properties. An easy and distinguishing test is its ready inflammability, 
 burning with a faint blue flame and giving off an irritating odor. It 
 will not dissolve in water, but is soluble in carbon disulphide. It is a 
 non-conductor of heat, and the warmth of the hand sometimes causes 
 it to crackle or break. 
 
 Preparation. 
 
 In Louisiana and Texas the crude sulphur is mined by melting with 
 superheated steam and then pumping the liquid to the surface, where 
 it cools and Sgain becomes solid. 
 
94 CALIFORNIA STATE MINING BUREAU. 
 
 This method yields an excellent quality of sulphur without the 
 formation of sulphur dioxide. The largest part of the world's suppl.y 
 of sulphur now comes from these two states. 
 
 At the refineries, the raw material from the mines is treated by a 
 process of sublimation, condensation, grinding and classification 
 through various sizes of screens for the production of the many grades 
 of pure sulphur. 
 
 Treatment with a solution Avhich boils above the melting point of 
 sulphur has proven successful for many ores. A solution of calcium 
 chloride is used and the ore suspended in an iron crate in this boiling 
 solution. The sulphur melts, drops to the bottom of the tank, and 
 is drawn off, while the impurities remain in the crate, a fairly pure 
 product is obtained with no loss. 
 
 TALC-SOAPSTONE. 
 
 The United States produces and uses more talc than any other 
 coiintry in the world. The producing states are California, Georgia, 
 Maryland, Massachusetts, New Jersey, New York, North Carolina, 
 Pennsylvania, Vermont and Virginia. New York and Vermont are 
 the largest. producers. 
 
 The imports for 1917 were less than one-tenth of the domestic pro- 
 duction, but a large percentage of that which was imported was of 
 very high grade. More than half of the imports come from Canada. 
 
 The price in 1917 ranged from $3 to $8 per ton for the lowest grade 
 material, the rough or crude talc, while the highest grade, which is 
 used for insulators, gas tips, etc., brought from $50 to $200 per ton. 
 The value of the crude is greatly increased by grinding, in which 
 state it is worth from $5 to $20 per ton. 
 
 Industrial application and uses. 
 
 In its natural state talc appears as the so-called French chalk and in 
 crayons used by tailors. In ground form it is most commonly seen 
 as toilet powders, lubricating mixtures, etc., although its most exten- 
 sive use is as a filler in the manufacture of paper. Much is used for 
 insulators, gas tips, etc., and in the manufacture of rubber and cer- 
 tain kinds of paints. 
 
 Soapstone is used in the manufacture of laboratory table tops, laun- 
 dry tubs, tanks, sinks, fume hoods, switchboards and in general^ 
 insulation. 
 
 Properties and ores. 
 
 Talc and soapstone are generally regarded as synonymous. How 
 ever, talc is a mineral, while soapstone is a massive rock composed 
 almost entirely of talc. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 95 
 
 The mineral talc is a hydrous silicate of magnesium (H2Mg3Si40io), 
 remarkable for its softness, greasy luster and feel and its heat-resisting 
 qualities. It is one of the softest minerals, being taken as number 
 one in the scale of hardness. In color it may be white, gray, pale 
 green or brown. Quite light (specific gravity 2.7-2.9). Insoluble in 
 ordinary acids, difficultly fusible and has low electric conductivity. 
 Occurs in compact, foliated masses in metamorphic areas and as talc 
 schists and gouge in mines. Generally a hydration product in the 
 alteration of magnesian silicates and is often associated with serpen- 
 tine and actinolite. 
 
 Distribution. 
 
 Talc and soapstone occur widely distributed throughout California, 
 but only a few deposits have proven of commercial value. High grade 
 deposits have been developed in Inyo and San Bernardino counties, 
 and considerable production has been made in Amador, El Dorado and 
 Tulare counties. Occurrences have been noted in almost every county 
 in the state. 
 
 Tests. 
 
 Distinguished by its softness, greasy, pearly luster and greasy feel. 
 Not acted upon by hydrochloric or sulphuric acid. Gives a little water 
 upon intense ignition in the closed tube. Very difficultly fusible. 
 
 The massive soapstone variety is generally schistose and grayish 
 green in color, and has a very greasy feel. 
 
 Preparation. 
 
 Soapstone is cut into slabs for the purposes mentioned above, while 
 the mineral talc, or exceptionally pure soapstone, is ground for powder, 
 and other uses. 
 
 TIN. 
 
 Along with the other metals, but probably to less extent, the use for 
 tin has increased with the war industries. It is one of the oldest 
 known metals, and was obtained from the British Isles long before the 
 Christian era. Many of the most ancient bronzes contain tin. The 
 Cornwall mines in England were famous for a long period, but are 
 now practically exhausted. More than one-half of the world's pro- 
 duction is obtained from placers, mainly in the Malay Peninsula, the 
 islands of Banca and Billiton near Sumatra, and Australia. The 
 United States is the largest consumer of tin among the nations, and 
 is supplied mostly by imports. In 1917 there were 71,845 short tons 
 
96 CALIFORNIA STATE MINING BUREAU. 
 
 of tin imported, and the t(ital domestic production was only 90 short 
 tons. Besides the countries mentioned above, imports were received 
 from England, Bolivia and China. 
 
 In California tin has not been produced commercially since 1891 
 and 1892. During these two years about 251,000 pounds valued at 
 $60,000 were produced from a small deposit near Corona in Riverside 
 County. 
 
 Industrial application and uses. 
 
 Tin is used in making tin plate, tin foil, and various alloys such 
 as solder, bearing metals, electrotype metal and bronze. Solder is 
 one-third tin and two-thirds lead. Tin amalgam is used to coat mir- 
 rors. Ordinary tin-ware is sheet iron, coated by dipping it into molten 
 tin, and hooks, nails, etc., are similarly treated. Pins are made of 
 brass, and coated with tin. 
 
 Chlorides of tin are used in the silk industry and in dyeing and 
 printing cloth, such as calico. The oxides are used for enameling. 
 
 Properties and ores. 
 
 Native tin (Sn) is a pure white metal, with metallic luster, soft • 
 (hardness 2.0), malleable and quite heavy (specific gravity 7.2). Does 
 not tarnish readily in the air. Occurs in rounded grains. 
 
 There are two principal ores, a sulphide and an oxide. 
 
 Cassiterite (SnOa) Tin oxide. Tin stone. This is the principal 
 ore of tin, from which practically all of the metal is obtained. It is 
 rare in California. Contains 78.7% Sn. and 21.3% O. Color black, 
 brown or yellow, streak pale brown to gray, adamantine luster, hard- 
 ness 6.7, gravity 6.4 to 7.0. Occurs massive, in grains, square prisms, 
 octohedrons or twins. Cleavage indistinct. Resem^bles dark garnet 
 or tourmaline. Found in veins in granite, gneiss and mica schist, 
 fxssociated with pyrite, topaz, tourmaline, talc and mica. 
 
 Stannite (SnSgCugS.FeS) Tin sulphide. Tin pyrites. Contains 
 27% tin, 3% copper, 30% sulphur and 13% iron. Steel gray to iron 
 black in color, black streak, brittle, hardness 4.0, gravity 4.3-4.6. 
 Occurs commonly massive or in grains. 
 
 Distribution. 
 
 Small amounts of stream tin are recovered in Alaska in connection 
 with gold dredging. It has also been produced to some extent in the 
 Black Hills in South Dakota and in North and South Carolina. 
 
 In California it has been found in Riverside, San Diego, Fresno, 
 Plumas, Siskiyou and Trinity counties. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 97 
 
 Tests. 
 
 To test cassiterite, the powdered mineral when heated before the 
 blowpipe on charcoal with sodium carbonate and charcoal powder 
 gives globules of metallic tin. The fused mass may have to be crushed 
 and washed to show the metallic globules. If a fragment of the min- 
 eral is treated with dilute hydrochloric or sulphuric acid and granu- 
 lated zinc, hydrogen is generated and the fragment of mineral is 
 coated with tin, which has a dull gray appearance. This becomes 
 bright when rubbed with the hand and gives off a characteristic odor. 
 
 Stannite when fused alone on charcoal gives a white coating of tin 
 oxide. After heating it is slightly magnetic. 
 
 Metallurgy. 
 
 The oxide cassiterite, is reduced with coal or charcoal in either a 
 blast or reverberatory furnace. 
 
 TUNGSTEN. 
 
 The increase in the production of tungsten in California has been 
 phenomenal. In 1914 the tungsten produced was valued at $180,575. 
 In 1916 this had increased to a production valued at $4,571,521. Pre- 
 vious to 1915 a single company produced almost all of California's 
 tungsten. Because of the high prices prevailing in the latter part of 
 1915 and in 1916, prospecting was greatly stimulated and' the tungsten- 
 bearing areas in the southern part of the state in Kern and San 
 Bernardino counties were considerably extended. Deposits were also 
 found and opened up in Inyo County. 
 
 The above recent production in California is more noticeable, in 
 view of the fact that before 1900 the total production in the United 
 States was insignificant, because of imports from China and Bolivia, 
 which are low-paid labor countries. 
 
 Tlie value of tungsten ore is generally based upon the content of 
 tungsten trioxide (WO3), and quotations are made per unit, the unit 
 being 1% of WO3 in a ton. In the early part of 1914 prices were low, 
 being $6.50 per unit. Such a price offered slight inducement to the 
 miner or prospector, and as a consequence, the production was lower 
 even, than in previous years. Toward the end of the year, due to 
 the war, the price raised to $9 per unit, and the demand for the ore 
 was greatly increased. In 1916 the price roi^ to $36 per unit for 
 60% WOJ. 
 
 Industrial application and uses. 
 
 Tungsten is used in the greatest amounts as an alloy with steel. 
 It produces a hard, tough variety which is capable of holding its 
 
 7—2484 
 
98 CALIFORNIA STATE MINING BUREAU. 
 
 temper up to nearly a red heat. It is used either alone or with 
 molybdenum or chromium, in such steels. The product is made into 
 armor plates, projectiles, steel tools, etc. It is used in the manufacture 
 of filaments for electric light bulbs. Although millions of bulbs are 
 made every year, the amount of tungsten used in this way is very 
 small, owing to the fineness of the filaments. It is used in place of 
 platinum for crucibles and electric furnaces, and for chemical appara- 
 tus, on account of great resistance to acids. Minor uses are for spark 
 plugs, phonograph needles, etc. 
 
 Properties and ores. 
 
 Tungsten (W) is a hard, heavy, tough metal. Hardness 4.5 to 8.0. 
 Specific gravity 19.3-20.2. It has a high melting point and for this 
 reason is obtained from its ores in the form of a powder. It is very 
 resistant to the action of the atmosphere and ordinary acids. It forms 
 alloys readily with other metals. 
 
 The principal ores of tungsten are scheelite, wolframite, hiibnerite, 
 and ferberite. 
 
 Scheelite (CaW04). Calcium tungstate. White, yellow, green or 
 brown mineral, with a vitreous or adamantine luster. Transparent or 
 translucent. Hardness 4.5 to 5.0. Gravity 6.0. Occurs massive or in 
 pyramidal crystals. It is the principal ore of tungsten in California, 
 and is produced in the largest quantities. 
 
 Huhnerite, wolframite and ferberite are similar, being tungstates 
 of iron and manganese. The first-named is essentially a manganese 
 tungstate, with a minimum of iron. The last-named is essentially 
 iron tungstate, with a minimum of manganese; and wolframite con- 
 tains iron and manganese in about equal proportions. No ferberite 
 has thus far been found in California. Wolframite — hiibnerite ; color, 
 brownish black to brownish red; streak dark brown to black. Luster 
 metallic to submetallic; hardness 5.0-5.5; gravity 7.2-7.5. Occurs 
 massive or in thick tabular crystals. 
 
 Distribution. 
 
 In the Atolia District in western San Bernardino County, scheelite 
 veins occur in granite. Quartz and calcite accompany the scheelite 
 as vein minerals. In the adjoining Stringer or Kandsburg District in 
 eastern Kern County, the veins are narrow stringers or seams of i 
 scheelite in schist, and are closely associated with gold bearing quartz 
 veins, although, for the most part, gold and tungsten are not found 
 in the same vein. In both the Bishop and Ubehebe Districts in Inyo 
 County the ores occur along or near the contact of granite and lime- 
 stone. In the latter district the ores are scheelite and hiibnerite, while 
 in the former district small crj^stals of scheelite are associated with rose 
 
COMMERCIAL MINERALS OF CALIFORNIA. 99 
 
 quartz, garnet, pyrite, magnetite and other minerals, in the Signal 
 District in San Bernardino County the ore, mostly wolframite, occurs 
 in quartz veins in granite or along the contact of granite and limestone. 
 There are other known deposits in Fresno, Madera and Nevada counties. 
 
 Tests. 
 
 The mineral is finely pulverized and heated with hydrochloric acid 
 (HCl). If tungsten is present, a yellow powder, tungsten trioxide 
 (WO3) will be produced. Upon the addition of metallic zinc (tin or 
 lead) the solution will turn indigo blue, the intensity of the color 
 depending upon the amount of tungsten in the specimen tested. If 
 tlie mineral is insoluble, as wolframite, fuse with sodium carbonate, 
 and then dissolve in HCl and test as above. Wolframite and hiibne- 
 rite may also be tested for manganese. They give to the borax bead 
 a violet color. 
 
 Metallurgy. 
 
 The ore is ground fine and roasted in a reverberatory furnace with 
 sodium carbonate, in the form of soda ash, and a small amount of 
 sodium nitrate. The product is leached in hot water, and the insoluble 
 tungstate decomposed by hydrochloric acid. The resulting tungstic 
 trioxide (WO3) is reduced by charcoal, in graphite crucible.s in gas, 
 coke or electric furnaces. 
 
 Ferro-tungsten, containing from 50% to 80% tungsten, is made 
 by smelting concentrate in an electric furnace. Coke is the common 
 reducing agent and lime and silica are added to form a suitable slag. 
 Fluorspar is used to aid liquefaction. Hematite is used as a decar- 
 l)onizer. 
 
 VANADIUM. 
 
 There has been no production of vanadium in California up to the 
 present time. The richest known deposits are located in Peru. 
 
 Industrial application and uses. 
 
 Vanadium is used in the manufacture of very high grade steel, 
 from which are made various parts for automobiles, aeroplanes, loco- 
 motives, etc., and also, armor plate, war munitions and high-speed 
 steel cutting tools. It is to a large extent replacing nickel in this 
 regard. 
 
 Dental and surgical instruments, razors, etc., in fact all tools re- 
 quiring a keen cutting edge of toughness and lasting qualities are 
 made from vanadium steel. Smaller quantities are used in the form 
 
100 CALIFORNIA STATE MINING BUREAU. 
 
 of vanadium salts, in dyeing and printing cloth, and in the manufac- 
 ture of ink, glass and porcelain. Recently it has come into use in the 
 manufacture of a tough, dense rubber, which is absolutely oil and 
 water proof. 
 
 Properties and ores. ' 
 
 Vanadium (V) is a gray metal with a silver-like metallic luster. 
 It is not tarnished by air or water at ordinary temperatures. Spe-, 
 cific gravity 5.6. Very hard, scratches quartz. It is a rare element 
 found in- vanadates or salts of vanadic acid. 
 
 The principal commercial ores are roscoelite, vanadinite, patronite, 
 carnotite and descloizite. | 
 
 Roscoelite. Vanadium mica. Hydrous silicate of vanadium, alum- j 
 inum and potassium. Color dark brownish or green, perfect basal 
 cleavage, pearly luster. Soft (hardness about 2.0), and light (specific 
 gravity 2.9). Found in small scales or plates. Contains from 20% 
 to 29% VoO,. 
 
 Vanadinite. Vanadate of lead and chlorine. Contains 19.4% VoO- 
 and 73% Pb. Color deep ruby red, sometimes yellow. Resinous or 
 adamantine luster. Hardness 3.0. Specific gravity 6.7-7.2. Brittle. 
 Generally occurs in small prisms. Hollow crystals are common. 
 
 Patronite. Vanadium sulphide (VS^). Contains 25.5% V, and 
 74.5% S. Dark green to black in color. Hardness 3.5. Specific 
 gravity 2.6. Generally amorphous with conchoidal fracture. 
 
 Carnotite. A comparatively new mineral discovered in Avestern 
 Colorado. Has a complex formula, containing uranium, vanadium, 
 potassium, calcium and other elements. A good ore of vanadium. 
 Color yellow. Very soft. Dull luster. Occurs as a powder in cava- 
 ties in sandstone. 
 
 Descloizite. Vanadate of lead and sometimes zinc and copper. Con- 
 tains 22.7% VoO-. Color red to yellowish, brown or green. Greasx 
 luster. No cleavage. Hardness 3.5. Gravity 6.2. 
 
 Distribution. 
 
 No commercial production of vanadium has yet been made in Cali- 
 fornia. Occurrences have been noted at Camp Signal near Goffs in 
 San Bernardino County. Recent discoveries are reported from Kern 
 County; also from Riverside County, in the 29 Palms District. 
 
 The domestic supply comes from Colorado, Nevada and Utah. Ores 
 are generally found associated with sedimentary rocks, sandstone, clays 
 and shales. Also found in a variety of forms in connection with gold, 
 lead, zinc and iron ores. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 101 
 
 Tests. 
 
 Vanadium minerals when treated with concentrated hydrochloric 
 acid (HCl) give a rich brown solution. It may be necessary to first 
 fuse the mineral with sodium carbonate before dissolving. If the 
 clear liquid is poured off into another test tube, and a strip of zinc 
 or tin added, the solution becomes first blue, then green and finally 
 violet. Also, when water is added to the original solution, the color 
 changes to green or disappears. If dilute acid is used to bring tte 
 mineral into solution the color is green or yellowish. 
 
 Heated with borax or salt of phosphorous in the oxidizing flame the 
 bead is yellow or deep amber, changing to yellowish green or colorless 
 when heated in the reducing flame. 
 
 Metallurgy. 
 
 Ores containing vanadinite and descloizite may be concentrated over 
 tables, by the ordinary methods because of the cry'-stalline nature of 
 these minerals and the high specific gravity w^hich the lead gives them. 
 In the case of roscoelite, concentration is impossible. Carnotite has 
 been concentrated by air blast while the ore is being crushed. 
 
 Concentration by chemical means, using both alkalies and acids, 
 has been successful, but the processes are complicated. 
 
 The two common forms in which the concentrate is prepared for 
 use in the manufacture of ferro-alloys are, vanadium-pentoxide and 
 ferrous- vanadate. 
 
 The finely ground concentrate is heated in a reverberatory hearth 
 with sodium carbonate. The soda slag containing the vanadium is 
 leached and treated by several chemical processes for the production 
 of the pentoxide. 
 
 The raw concentrate may be leached in lead lined vessels with 
 sulphuric acid, and by decantation, evaporation and ignition vanadium 
 pentoxide is obtained. 
 
 Reduction to the metallic state and the preparation of ferro-vana- 
 dium is carried on in the electric furnace or by the aluminothermic 
 process. 
 
 ZINC. 
 
 Industrial application and uses. 
 
 Zinc is largely used in the form of sheets for roofing, cornices, pipes, 
 etc., in building construction, and for lining tanks and other com- 
 mercial utensils. Zinc plates are extensively used in electrical bat- 
 teries. Sheet iron dipped into molten zinc becomes coated and makes 
 the so-called 'galvanized iron.' Wire is also treated in this way. 
 
102 CALIFORNIA STATE MINING BUREAU. 
 
 Zinc is largely used in the manufacture of protective coatings and 
 paints. Zinc dust is used in chemistry and metallurgy. I 
 
 Anti-friction metals and other alloys are composed largely of zinc. ' 
 Babbitt's metal, for example, containing 69%. Brass is an alloy of 
 copper (65%) and zinc (35%). 
 
 Properties and ores. 
 
 Zinc is a bluish white lustrous metal whose physical properties vary 
 considerably with the temperature. At ordinary temperatures it is 
 brittle, but when heated it may be rolled into sheets and drawn into 
 wire and does not become brittle again upon cooling. When heated 
 to 200° C. it again becomes brittle and can be easily pulverized. It 
 does not tarnish in dry air, but ordinarily becomes coated with a 
 dark film. Soft (hardness 2.0), specific gravity 6.9-7.2. The chief 
 ores are sphalerite, smithsonite, willemite, calamine, zincite and frank- 
 linite. 
 
 Sphalerite (ZnS) Zinc sulphide. Sometimes called 'jack,' and 
 'rosin jack.' Zinc blende. Contains 67% Zn, 33% S. Color yellow, 
 brown or black, streak white to yellowish brown, resinous or waxy lus- 
 ter, brilliant when broken, brittle, hardness 3.5-4.0, specific gravity 1.0. 
 Sometimes transparent or translucent. Typically associated with 
 galena. 
 
 Smithsonite (ZnCOg) Zinc carbonate. 'Dry bone.' Contains 
 ZnO 64.8%, CO2 35.2%. Color gray, grown or green, vitreous luster, 
 brittle, hardness 5.0, specific gravity 4.4. Occurs in drusy crystals or 
 massive, often bone-like, associated with silver lead ores and the 
 silicates of zinc. 
 
 Willemite (Zn2Si04) Zinc silicate. Color light or apple green to 
 flesh color, brittle, vitreous luster, hardness 5.5, specific gravity 
 3.89-4.18, basal cleavage. Occurs massive and granular. 
 
 Calamine (HgZngSiOg) Basic or hydrous zinc silicate. Color ^ 
 white, blue or brown, vitreous luster, hardness 4.5-5, specific gravity 
 3.4-3.5. Occurs in drusy masses or earthy. Found in oxidized por- 
 tions of zinc veins. 
 
 Zincite (ZnO) Zinc oxide. Contains 80.3% Zn and 19.7% 0.\ 
 Color deep or bright red, streak orange yellow, brilliant luster, hard 
 ness 4.0-4.5, specific gravity 5.68-5.74. Perfect ba^al cleavage. 
 Usually occurs in foliated masses. i 
 
 Franklimte is an iron oxide, resembling magnetite, and contains 
 zinc and manganese. 
 
COMMERCIAL MINERALS OF CALIFORNIA. 103 
 
 Distribution. 
 
 The largest production in California in 1918 was from Shasta 
 County, followed in order by Inyo and San Bernordino counties. In 
 Shasta County the zinc ores are associated with copper, while those 
 of Inyo and San Bernardino are associated mostly with lead-silver 
 ores. Zinc minerals are found in small quantities in many counties 
 in the state. Electrolytic zinc smelters were in operation by the 
 ]\Iammoth Copper Mining Company at Kennett, Shasta County, and by 
 the Bully Hill Copper Mining and Smelting Company at Winthrop, 
 Shasta County, but it is understood that these are now closed. 
 
 Tests. 
 
 Zinc volatilizes when heated before the blowpipe on charcoal and 
 gives a canary yellow coating of zinc oxide, which becomes white when 
 cold. Fragments of zinc minerals may be tested in this manner. 
 With some minerals it may be necessary to use a flux of one-half volume 
 of sodium carbonate. The test requires first the reduction of zinc 
 to the metallic state and then its volatilization, hence great care must 
 be taken in the manipulation of the blowpipe flame, in order that 
 the metallic particles are not blown away. If the charcoal is moistened 
 with cobalt nitrate before making the test, the coating will have a 
 green color which is very characteristic. Infusible or light colored 
 zinc minerals when powdered and made into a paste with cobalt nitrate 
 and heated, assume a green color. 
 
 Metallurgy. 
 
 The process of zinc smelting which has been in general use in this 
 country for many years, is as follows: The ore is first roasted in 
 open hearth furnaces to remove most of the sulphur. It is then 
 intimately mixed with about 40% of fine coal and placed in retorts 
 made of excellent quality of fire clay. These retorts are from four 
 to six feet long and eight to ten inches in diameter and are arranged 
 in layers and tiers in the smelting furnace, each furnace containing 
 from 200 to 300 of these retorts. The furnace contains several fire 
 places and is fired by soft coal or powdered coal. 
 
 At 1200° to 1300° Centigrade, distillation takes place, the zinc 
 vaporizes and passes off to the condensing chambers where it is 
 condensed into molten form. The complete treatment of a charge 
 requires about twenty-four hours and the molten zinc is drawn from 
 the condensing chamber at various intervals. At the end of the treat- 
 ment period, the temperature is raised to remove the last traces of 
 zinc. The average life of a retort is about 40 charges. 
 
104 CALIFORNIA STATE MINING BUREAU. 
 
 Recently great progress has been made in the electrolytic treatment 
 of zinc ores. This method is especially applicable to copper-zinc ores, 
 or to low grade ores. The method of treatment consists of first roast- 
 ing the ore in an open hearth furnace, then leaching with sulphuric 
 acid. The copper is precipitated from the solution by zinc dust and 
 the metallic zinc obtained by electrolysis. 
 
 Concentration of zinc ores by flotation is now being practiced quite 
 extensively. 
 
COMMERCIAL MINERALS OF CALIPORNLV. 105 
 
 APPENDIX. 
 
 PHYSICAL PROPERTIES OF MINERALS. 
 Under physical properties the following are here explained: 
 
 Hardness. 
 
 The place given a mineral in a scale of hardness, now in general 
 ii>e, 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