192 



BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



specimen in the collection of Col. W. A. Roebling, establish the 

 identification and isometric symmetry of the mineral. 



Measurements on cuprite from Caledonia mine 



Cuprite in earthy and massive form, has also been reported from the 

 Monitor mine and probably occurs in other oxidized copper bearing 

 ores in the copper belt east and south of Mullan. 



WASHINGTON AND ADAMS COUNTIES 



In the Seven Devils district cuprite is sparingly present in the 

 oxidized copper ores of the contact metamorphic deposits. It is 

 fairly abundant in the Blue Jacket mine, 94 and while not abundant 

 is not unusual in the Peacock mine. 95 



Cuprite has been reported to occur in a silver-bearing ore at the 

 River Queen deposit, one-half mile above Ballards. A specimen 

 in the National Museum labeled as from Little Bar on Snake River 

 contains masses of granular cuprite up to 5 cm. in diameter, con- 

 taining cavities filled with capillary chalcotrichite. The associated 

 minerals are chrysocolla and brown impure copper silicate. 



TENORITE (230) 

 MELACONITE 



Cupric oxide, CuO. 



Amorphous-monoclinic (?) 



To what extent the black copper oxide occurs in Idaho is not 

 known. The mineral has frequently been mentioned as occurring 

 in oxidized copper ores of the State, but many of these may have 

 been misidentified, the material, in some cases at least, being black 

 copper silicate as further discussed under "melanochalcite." The 

 principal localities thus far reported are as follows: 



CUSTER COUNTY 



Bright black layers which envelop nodular masses of cuprite from 

 the 300-foot level of the Empire mine in the Alder Creek district 

 (Mackay) are probably tenorite. The material has malachite and 



•« D. C. Livingston and F. B. Laney. Bull. Idaho Bur. Mines and Geol., No. 1, p. 73, 1920. 

 « Idem, p. 82. 



