122 BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



abundant in the Coon Dog No. 1 property in the Summit Flat dis- 

 trict, some veins carrying enough of the mineral to form a low grade 

 copper ore. Much of the chalcopyrite here is also blue from incipient 

 replacement by covellite. It is associated with pyrite and sphalerite 

 in quartz. 



CUSTER COUNTY 



Chalcopyrite is an important mineral in the Loon Creek district 

 where the ores of the important mines consist of auriferous chalcopy- 

 rite in a siderite-quartz gangue. The Lost Packer is the principal 

 mine working this type of ore and has produced $500,000, The 

 chalcopyrite, which is all massive or finely granular, occurs replacing 

 quartz or siderite along seams. It contains from 2 3^ to 3 ounces of 

 gold a ton and from 6 to 9 ounces of silver. All of the gold is ap- 

 parently contained in the chalcopyrite. 4 



In the Bayhorse district chalcopyrite commonly accompanies the 

 tetrahedrite-siderite ores of the Ramshorn and other mines. Fine 

 golden yellow bands of chalcopyrite border narrow veins of 

 tetrahedrite from the Ramshorn mine (Cat. No. 56521, U.S.N.M.) 

 and are mixed with tetrahedrite from the Bull of the Woods mine 

 (Cat. No. 56618, U.S.N.M.). In a specimen from the Utah Boy 

 No. 5 tunnel of the Ramshorn mine chalcopyrite occurs in drusy 

 crusts of minute crystals with galena in cavities in siderite-tetra- 

 hedrite ore. 



In the Alder Creek (White Knob, Mackay) district chalcopyrite 

 is by far the most abundant primary copper mineral in the ores 

 of the contact metamorphic deposits in limestone. It occurs as an 

 interstitial filling in garnet rock and, in a few places, as grains con- 

 centrically distributed in garnet crystals. Magnetite and chalcopy- 

 rite seldom occur in the same hand specimen and even in an ore- 

 shoot where one is abundant the other is scarce. It is intimately 

 associated with pyrite and in some cases completely surrounds garnet 

 crystals. 5 



FREMONT COUNTY 



Chalcopyrite occurs in barite with copper pitch and other altera- 

 tion products in ore from The Weimer Copper mine 2 miles east of 

 Kaufman in the Skull Canyon district. It is probably the principal" 

 primary copper mineral of this mine, the ore of which is very largely 

 oxidized. 



IDAHO COUNTY 



Chalcopyrite is an accessory mineral in gold ores of a number of 

 mining districts. In the Buffalo Hump district the ores of the 



* J. B. Umpleby. U. S. Geol. Survey Bull. 539, p. 96, 1913. 

 s J. B. Umpleby. U. S. Geol. Survey Prof. Paper 97, 1913. 



