ART, XXXI -ON THE MINERALOGY OF NEVADA. 



By W. J. Hoffman, M. D. 



This report is based Drimarily upon the collectiou tnade in 1871 while 

 a member of the expedition for the exploration of Nevada and Arizona.* 

 Since that time I have received well-authenticated species from vari- 

 ous sources, chiefly in Nevada ; and those which have not come under 

 my personal observation have been accredited to the proper authorities. 

 The original collection is now at the National Museum, excepting in a 

 few instances, in which the materials were consumed in making the 

 necessary analyses. The only interesting feature which I shall mention 

 here is the occurrence of mangauiferous compounds in a belt of lime- 

 stone, chiefly traceable from Austin south, and eastward toward Hot 

 Spring Caiion. Most of the compounds containing antimony in various 

 forms occur chiefly throughout the western portion of the State, while 

 in the eastern portion the haloid compounds predominate. Neither of 

 these, however, are in any way governed by the occurrence of so-called 

 "sulphuret ores", as these are distributed pretty generally. 



In addition to the above, a few remarks upon, and a list of, the ther- 

 mal and mineral springs visited are added; also notice of some of the 

 rarer minerals found in Owens Valley, California. 



I embrace this opportunity of acknowledging my indebtedness to the 

 following-named gentlemen for information and specimens which I 

 could not have obtained through any other sources : Mr. Julius Partz, 

 superintendent and afterward assayer of the mines in Blind Springs 

 District, California; Mr. Eichard Stretch, formerly engineer of the Vir- 

 ginia City Mines; Mr. Leon and the Canfield Bros., Belmont; the. 

 Messrs. Ogden, of Morey ; Thomas Shaw, Gold Mountain ; and Mr. W. 

 S. Keys, superintendent of the Eareka Consolidated Mines. Dr. A. E. 

 Foote, of Philadelphia, Pa., furnished me with several names, to which, 

 (when not on my list) his name has been appended as authority. In 

 several instances, also, I have quoted from Professor Dana's Manual of 

 Mineralogy for localities unknown to me personally. The localities 

 cited are those in which the specimens named occur or did occur in 

 their greatest purity or finest crystallizations. 



Agate. See Silica. 



Albite. In rhyolite, at Eureka and at Morey; massive, granular, at vari- 

 ous points in Fish Lake Valley, rarely in crystals. Fine crystals in 

 trachyte on the Colorado Eiver. 



* Now knowa as United States Geographical Surveys West of 100th Meridian. 



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