CENTRAL AND EASTERN NEVADA. 421 



Besides the above determined ingredients, the ore contained manganese, 

 magnesia, sulphur, and carbonic acid. Minute traces of bromine were also 

 detected, but no iodine. The amount of chlorine present is sufficient to 

 combine with 4.998 per cent, of silver, leaving .678 of one per cent, of silver 

 to be combined with arsenic and sulphur. The carbonic acid was undoubt- 

 edly combined with the lime, magnesia, lead, and copper. 



The minerals of the White Pine district are very few. The following 

 list comprises, as far as known, all those that have as yet been identified : 

 Quartz, calcite, (white and black,) gypsum, fluorite, barite, black oxide of 

 manganese, rhodonite, rhodochroisite, cerargyrite, galena, cerussite, azurite. 



Quartz and pure white calcite are found associated together in all the 

 argentiferous ore-bodies. The black calcite occurs in many of the mines, and 

 is regarded by the miners as a good indication of ore. Gypsum, apparently 

 rare, is found in small quantities in the Pogonip and Othello and Truckee mines. 

 Fluorite, rare, of a deep purple color; barite, associated with fluorite. Black 

 oxide of manganese occurs in many of the mines ; abundant in the Pogonip 

 and Othello and Pocotillo. Rhodonite (silicate of manganese), of flesh-red 

 color, occurs associated with rhodochroisite (carbonate of manganese) in the 

 Pocotillo mine. Cerargyrite (chloride of silver), massive, also reported to 

 have been found in the Eberhardt mine in small crystals, color grayish-green, 

 yellowish-green. The ''gray" and ''green chlorides" of the miners have appa- 

 rently the same composition, the color depending on the manner in which the 

 other mineral substances are intermixed with them and on the more or less 

 disintegrated condition of the quartz. Azurite (blue carbonate of copper) 

 forms a thin coating upon the quartz and limestone in many localities. It 

 occurs only sparingly in most of the mines of Treasure Hill. At the north 

 end of the hill it is somewhat more abundant, particularly at the Virginia 

 mine ; on the Base Metal Range it is of common occurrence. Galena occurs 

 in several localities on the Base Metal Range, associated with cerussite (car- 

 bonate of lead). The developments upon the Base Metal Range have extended 

 to such a short distance below the surface that they have, as yet, afforded very 

 little opportunity to study the mineralogical character of the ore. 



