Page:The American Cyclopædia (1879) Volume III.djvu/608

 C02 CALIFORNIA of California presents some marked peculiari- ties. Of the known mineral species, number- ing about 700, only about 100 are found. Sili- cates, so common in volcanic rocks, and fluor spar and barytes, so abundant in the vein stones of other mining countries, are of rare occurrence. A not less marked feature is presented in the absence of zeolites. The number of minerals that have been success- fully worked is exceedingly limited, compris- ing chiefly gold, mercury, copper, and silver. Of the mineral productions of California gold is beyond comparison the most important, the most remarkable gold fields in the world exist- ing in the state. Though the metal has been found E. of the Sierra Nevada, among the mountains of the coast, and in various other localities, almost the entire product of the state has been derived fr6m the great aurifer- ous belt on the W. slope of the Sierra Nevada, extending from Fort Tejon northward into Oregon, and measuring about 220m. by 40 wide. The gold deposits of the N. and S. extremi- ties of this belt are of comparatively little im- portance. The central portion, embracing the W. parts of Mariposa, Tuolumne, Calaveras, Amador, El Dorado, Placer, Nevada, Sierra, and Plumas, and the E. part of Yuba and Butte counties, forms the great gold-mining region. The gold, with rare exceptions, is found in the native or metallic state. It is never perfectly pure, but is always alloyed with more or less silver, and sometimes also with small quanti- ties of other metals. It occurs extensively in two distinct and well defined conditions, viz. : in the solid rock, usually in veins, and in allu- vial deposits in the form of minute scales, coarse grains, and larger pieces, more or less water-worn and mixed with the sand and graveL The former class of deposits are known as auriferous quartz lodes, and the lat- ter as placers. From this circumstance three distinct modes of mining have arisen, viz. : placer, hydraulic, and quartz or vein mining. In the first named, the metal is obtained by washing the auriferous gravel, by which process the gold, owing to its great specific gravity, is speedily separated from the sand and earthy matter. Owing to the simplicity of the pro- cess, placer mining was at first chiefly carried on, but has been largely superseded by hydraulic and quartz mining, which require more capital, skill, and complicated machinery. In hydraulic mining a body of water in a compact continu- ous stream is directed with great force upon banks or walls of auriferous earth and cemented gravel deposits, by means of powerful nozzles. The matter thus loosened, together with the water, is received in sluices in which the gold, having precipitated, is collected, while the worthless debris is carried away. In this man- ner many large hills have been levelled. The auriferous quartz occurs in veins and ledges, which are very numerous, and have a general N. N. W. and 8. S. E. direction, parallel with the central axis of the Sierra Nevada. The 1848. 1849. 1850. 1851. 1852. 1853. 1654. 1855. $10,000,000 40,000,000 60,000,000 55,000,000 60,000,000 65,000,000 60,000,000 66,000,000 1857. 1658. 1869. 1860. 1861. 1862. 1863. 1864. $55,000,000 50,000,000 50,000,000 45,000,000 40,000,000 84,700,000 80,000,000 26,600,000 1865. 1666. 1S67. 1868. Ih69. 1870. 1871. 1872. $28,500,000 26,500,000 25,000,000 25,000,000 22.500,000 24:000,000 25,000,000 24,000,000 Total $981,800 000 rock is crushed in powerful mills and the gold extracted by amalgamation. The first of these mills were erected in 1851. In 1870 there were 421 (including 8 silver and 5 gold and silver), of which 200 were operated by steam, 198 by water, and 17 by steam and water. The total cost of machinery was $0,500,000; total num- ber of stamps, 4,073. In addition to the stamps there are several hundred arastras. These mills are distributed among nearly all the counties of the state; but the most important mining counties are Nevada, containing 79 quartz mills with an aggregate of 742 stamps ; Tuo- lumne, 41 mills ; and El Dorado, 40. The most accurate estimate of the gold product of Cali- fornia since the discovery of that metal in 1848 is as follows : Next to gold, probably the most important mining interest of California is the production of quicksilver, which is obtained only from its sulphuret or cinnabar, of which deposits are found at many points ; it occurs in the Sierra Nevada and in triassic rocks in the S. portion of the state, but most abundantly in the Coast range. In 1870 there were' four establish- ments for smelting quicksilver, of which two were in Santa Clara co., and one each in Fres- no and Lake counties. The capital invested was $3,500,000; wages paid during the year, $181,000 ; value of materials, $837,800 ; of pro- ducts, $1,027,680. The New Almaden mine, in Santa Cl'ara co., the oldest and most ex- tensive in the state, produced from July, 1850, to December, 1807, 35,333,586 Ibs. of quicksilver, or 461,887 flasks, from 214,775,175 Ibs. of ore. The total production of the state in 1869 was 33,600 flasks; in 1870, 29,546; in 1871, 31,881. The exports of quicksilver from San Francisco during the five years ending with 1871 amounted to 120,767 flasks, of which 51,346 were to China, 42,391 to Mexico, 1 1, 600 to South America, and 1 0, 700 to New York. Ores of silver abound in various parts of the state, and some of them are very rich ; but silver mining has not yet been devel- oped to such a degree as to render it of any considerable importance. Argentiferous galena is mined at numerous localities in San Bernardi- no, Mono, Alpine, and Inyo counties ; the mines of the last named county exceed in productive- ness all others within the state. In 1870 there were in the last three counties 8 silver quartz mills, constructed at a cost of $332,500, besides 5 gold and silver quartz mills in Inyo co. Argen- tiferous copper ores are found in that part of the state bordering on Arizona, and argentiferous