130 DESCRIPTIONS OF MINERALS. 



Chili •, at Huanca Velica and some other points in Peru ; at St. Onofre 

 and other places in Mexico ; in California and Idaho. 



The most noted of the California mines, New Almaden, is situated 

 in Mine Hill, Santa Clara County, south of San Francisco. The rocks 

 are altered Cretaceous slates, talcose in part, with beds of serpentine 

 either side, and associated also with beds of jasper or siliceous slate. 

 The New Idria mine is in Fresno County, in the Mt. Diablo Range, and 

 was discovered in 1855. The rocks are more or less altered silico- 

 anrillaceous and siliceous slates and sandstones, and the cinnabar is 

 distributed irregularly through them ; between this and the Aurora 

 Mine on San Carlos (the highest peak of the Diablo Range, 4,977 feet), 

 there is much serpentine (in which is chromic iron') and siliceous rock 

 or slate. In Napa Valley, Napa County, north of San Francisco, there 

 are other valuable mines situated in rocks closely similar, as Whitney 

 states, to those affording quicksilver at New Almaden. They are in 

 a serpentine belt, the cinnabar being in some places in the serpentine, 

 but mostly in the peculiar siliceous rock associated with it. Native 

 mercury occurs vith the cinnabar. 



The product of the California mines of mercury in 1^74, is given as 

 follows by Raymond, in his " Mineral Resources for 1875" : 



New Almaden Santa Clara Countv 9,081 flasks. 



New Idria Fresno " * 7,000 " 



Cerro Bonito " " 900 " 



California Napa " 8,000 " 



Manhattan " " 620 " 



Phoenix " " C c 5 " 



Washington " " 200 " 



Redington Lake " 7,200 " 



California Borax " " 570 " 



Great Western " " 1,900 " 



Buckeye Colusa " 700 " 



Missouri Sonoma " 200 " 



Oakland " " 807 " 



Saint John Solano " 1,900 " 



Which, with the additions from a few other less productive open- 

 ings, make a total of 34,254 flasks, or over 2,400,000 lbs. The yield 

 in 1807 was 44,386 flasks, or about 3,400,000 lbs. The total yield of 

 the world in 1872, is stated by Phillips at 6,670,000 lbs. avoirdupois. 



COPPER. 



Copper occurs native in considerable quantities ; and also 

 combined with oxygen, sulphur, selenium, arsenic, anti- 

 mony, chlorine., and as carbonate., phosphate, arsenate, sul- 

 phate, and vanadate. The ores of copper vary in specific 

 gravity from 3-5 to 8*5, and seldom exceed 4 in hardness. 



