THE MINERALS OF IDAHO 121 



this is so widespread in the State that only a part of the occurrences 

 which hare been specially noted can be mentioned. 



ADAMS COUNTY 

 (Including Washington County in part) 



In the contact met amorphic copper deposits of the Seven Devils 

 districl chalcopyrite is abundant in the ore, although subordinate 

 to bornite in all the deposits of this type except the Arkansaw mine 

 in which bornite is but sparingly present and chalcopyrite is the 

 only important ore mineral. Chalcopyrite is the principal primary 

 mineral in peculiar pegmatitic quartz-orthoelase filled veins at the 

 Lucky Strike prospect occasionally intergrown with bornite and 

 partly enriched by replacement by chalcocite and covellite and it 

 occurs similarly, though in small amount, intergrown with bornite 

 in the Panama Pacific mine, where it has developed in hair lines 

 and dots along cleavage lines in bornite. It is the principal ore 

 mineral in the Gaarden mine and is abundant replacing andesite 

 along a fracture zone up to 2 meters wide in the River Queen 

 mine. 2 



BANNOCK COUNTY 



In the Fort Hall mine, Fort Hall district, chalcopyrite constitutes 

 an ore of copper. It occurs as granular masses with some pyrite and 

 galena in a gangue of quartz and white calcite forming seams in 

 folded shaly limestone. 3 



BLAINE COUNTY 



In Blaine County chalcopyrite occurs in moderate amount in 

 the Argent and Jay Gould and other lead-silver mines of the Hailey 

 or Wood River district. In the gold veins it is a constituent of 

 heavy masses of auriferous sulphides as in the Croesus, Camas, Tip 

 Top, and other mines. 



BOISE COUNTY 



In Boise County chalcopyrite is a common constituent of the 

 auriferous sulphide masses of the gold veins. Specimens from the 

 Mountain Chief mine, Quartzburg district, contain chalcopyrite 

 intergrown with sphalerite and as bronzy yellow masses in heavy 

 aggregates of auriferous pyrite and arsenopyrite. In ore from the 

 Carroll-Driscoll mine chalcopyrite is accompanied by pyrite, sphal- 

 erite, and less tetrahedrite as masses of sulphides in quartz. The 

 chalcopyrite is blue along joints and fractures from replacement 

 by covellite. Small cavities in the ore contain minute blue sphenoidal 

 crystals of chalcopyrite coated by covellite. Massive chalcopyrite is 



1 D. C. Livingston and F. B. Lanoy. Idaho Bur. Geol. & Mines Bull. 1, pp. 37-06, 1920. 

 a F. B. Weeks and V. C. Heikes. Notes on the Fort nail Mining district, Idaho. U. S. Oeol. Survey 

 Bull. 340, pp. 175-183, 1908. 



54347— 26t 9 



