344 TRANSACTIONS OF THE 



mens in eighteen hundred and sixty-one. Found also at the Napoleon 

 and the Lancha Plana Mines ; and in Sacramento County, at the Cos- 

 umnes Mine. In Santa Barbara County^ occurs disseminated in grains in 

 the midst of serpentine rock. Arl?:t)ua, on the Gila Jiiver, about ninety 

 miles from Fort Yuma, at the Arizona Copper Company's mine ; asso- 

 ciated with red oxide of copper and gi-een carbonate, and spread in crys- 

 talline masses through a ganguc of calc spar. (Cabinet of the author.) 

 (For the ores of copper, see Chalcopyrite, Eed Copper, Vitreous Copper, 

 etc.) 



COPPEE GLANCE. 



Los Angeles County, at the Maris Mine, Soledad District, in grains and 

 irregular masses in a syenitic granite. It contains silver. The decom- 

 jiosition of this ore at and near the surface gives metallic copper, and 

 metallic silver, incrusting the surfaces of the granite where fissured. 

 This localit}' was known and worked as early as eighteen hundred and 

 fifty-three. In Arizona this is the most common ore of copper, especially 

 in Weaver District, near La Paz, or Olive City. It is usually argentifer- 

 ous, and is there associated with gold in quartz veins. Found also in the 

 Cahuabi Vallc}^ the Tajo, and the San Pedro Mines, and near Caborca, 

 in Northwestern Sonora. 



DEEBYSHIRE SPAE. 



Castle Dome District, Arizona. (See Fluor Spar.) 



DIAMOND. 



Butte County, Cherokee Flat, ten miles from Oroville. In well formed, 

 highly modified crystals, from one eighth to three sixteenths of an inch 

 in diameter, and generallj' of a pale straw yellow coloi*. Ci-ystallization 

 tetrahedral, like fig. 267, p. 24, Dana's System of Mineralogy. 



Idaho. — Eeported to exist on the Owyhee Elver. 



BIAJjJjOGITE— (Carbonate of Manganese.) 



Occurs abundantly in the silver bearing veins about Austin, Nevada. 

 By decomposition it becomes black, and discolors the upper parts of the 

 vein, but at and below the water line, with the unchanged ores of silver, 

 it has a delicate flesh red or jsink color. 



DOLOMITE. 



Amador County, in narrow, snow white" veins, traversing a talcose 

 chloritic rock, and bearing coarse free gold. (Cabinet of the author, 

 specimen presented by Mr. James.) Calaveras County, Angel's Camp, in 

 the Winter, Hill's, and other mines, massive, with the quartz veins, and 

 bears gold. Sometimes in fine crj-stals, lining cavities. San Bernardino 

 County, at the Armagosa Mine, bearing coarse gold. 



EMBOLITE. 



Is believed to occur in the surface ores of Lander County, Nevada, near 

 Austin, and of Washington District, further south, but has not been 

 certainly identified. 



