THE MINERALS OF IDAHO 



157 



LEMHI COUNTY 



Steel gray films and fibers occur occasionally in the ores of the 

 Junction district. 35 



OWYHEE COUNTY 



Pyrargyrite is a common ore mineral in the Silver City and adjacent 

 districts. In the Flint district grains of pyrargyrite 1 to 2 millimeters 

 in diameter were noted in ore from the Rising 

 Star mine, disseminated in white quartz with 

 other silver minerals. In the Dc Lamar mine 

 it was common in the silver stopes, and in 

 crevices immediately adjacent to the "iron 

 dike'' nuggets of pyrargyrite, miargyrite. and 

 argentite occur in soft streaks of whitish 

 kaolin. 36 In a specimen from a stope in a 

 raise in the east drift of the Silver City mine 

 pyrargyrite occurs as irregular large grains 

 loosely deposited upon crusts of quartz crys- 

 tals, with, irregular grains of fluorite. Speci- 

 mens from the Henrietta mine collected by 

 Lindgren showing abundant steel gray crys- 

 tals of miargyrite attached to quartz and 

 covered by white clay bear a few minute 

 deep red transparent crystals of pyrargyrite. 

 Several of these were measured on the 2-circle 

 goniometer. Some of them are simple, show- 

 ing only the prism (1010) with the rhombohe- 

 dron (1122), while others show the forms 

 (4151) and (4152). These crystals are illus- 



Fie 2<S "Pyr arc yritf C'ali* 



trated in Figures 26 and 27. The angles fornia shaft, silver city 

 measured are as follows : district, Owyhee county 



Measurements of pyrargyrite from Henrietta mine 



Quality, description 



Very good 



Excellent 



Very good 



Medium poor. 



Measured 



18 



30 18 



10 56 



11 06 



90 00 



24 26 



67 22 



50 26 



Calculated 



00 



30 00 



10 53 



10 53 



90 00 



24 28 



67 18 



50 17 



a Xumber of faces measured. 



s« J. B. Umpleby. U. S. Oeol. Survey, Bull. 528, p. 78, 1913. 



a Waldemar Lindgren. U. S. Geol. Survey, 20th Ann. Kept., pi . :;, p. 128. 



