732 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



Allemontite. Locality unknown. Also reported by Dr. Foote. (Pri. 

 com.) 



Alum. See Kalinite. 



Alunogen. At Mount Diablo, associated with kalinite. 



Amethyst. On the mesa, near the mouth of Eio Yirgen. 



Analcite. In small crystals in the La Libertad Mine, San Antonio Dis- 

 trict. In amygdaloid in the Black CaQon, Colorado River. 



Anglesite, Occurs sparingly in Eailroad District, at Hyko, and at 

 Mineral Hill. Across the State line at Partzwick, Cal., crystals were 

 obtained measuring .34 of an inch across. 



Ankerite. Occurs southeast of Camp Halleck. Locality unknown. 



Sp. gr.= 2.975. 

 Compositiou : 



Carbonate of lime 51.14 



Caibouate of magnesia 23. 48 



Carbonate of iron 18. 75 



Carbonate of manganese 6.20 



Oi'ganic matter 0. 43 



100. 00 



Antimony. See Stibnite. 



Apatite. In small crystals, with good terminations, at Lone Mountain. 



Aragonite. Crystals nearly one inch in length, with perfect terminations, 

 in a cave one mile south of Mineral Hill. The variety known as Flos 

 Ferri occurs in small quantities. 



Argentite. In small quantities in Cope and Bull Eun Districts. Spar- 

 ingly at Mineral Hill and Hyko ; more frequent at Palmetto. 



Arsenic. Antimonial arsenic, 17*. A compound, consisting of arsenic, 

 90.82, and antimony, 9.18, (=17 As -f 1 Sb), occurs in the Comstock 

 lead of the Ophir Mine, Washoe County, " Cal." {i.e., Nevada), in finely 

 crystalline, and somewhat radiated, reniform masses, between tin- 

 white and iron-black on a fresh fracture, but grayish black on tar- 

 nishing, unassociated with arsenolite, calcite, and quartz.* 



ArsenoUte. Ophir Mine. (Dana and Stretch.) Sparingly, in small 

 quantities, at Belmont. 



Astrophyllite. Eare, in small hexagonal laminse, at Silver Peak. 



Alunogen. Near Mount Diablo, frequently associated and mixed with 

 sulphur. Dr. Loew mentions this as occurring thirty-five miles 

 northwest of Silver Peak, having reference undoubtedly to the same 

 locality. 



Azurite. Occasionally in minute crystals at Bull Eun; in thin coatings 

 and seams at Hyko and Cope District ; rather more frequent at San 

 Antonio, Montezuma, and Philadelphia Districts. In beautiful crys- 

 tals at Mineral Hill. 



Beryl. Sparingly, ten miles north-northwest of Silver Peak. Some crys- 

 tals have been obtained, the largest measuring .75 of an inch across. 

 Color dull bluish-ash. 



*Dana's Manual of Mineralogy, New York, 1868, p. 18. 



