84 BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



shipped from one small chute. A little scheelite occurs with the 

 molybdenite. Adjoining this property is a deposit of oxidized copper 

 ore containing chrysocolla and azurite. 49 



LEWIS COUNTY 



A little molybdenite occurs in the Horseman property in the Deer 

 Creek Region in Lewis County, along with chalcopyrite in a gangue 

 of siderite. The vein minerals occupy a vein and partly replace the 

 crushed country rock, greenstone, along the fissured zone. 50 



WASHINGTON AND ADAMS COUNTIES 



Molybdenite is present in almost all openings of the contact meta- 

 morphic copper deposits but is nowhere abundant. It is most com- 

 mon in ores of the lower Queen tunnel, but even here it is of little or 

 no commercial importance. 51 A specimen from the lower Queen 

 tunnel shows small rosettes of folia of molybdenite in quartz with 

 pale green diopside. In one from The Blue Jacket mine flakes and 

 scales of this mineral appear in coarse columnar dark green epidote 

 associated with quartz containing small octahedrons of magnetite. 

 A very little molybdenite occurs in minute flakes associated with 

 chalcopyrite in quartz in Frenchy's claim. 52 



ARGENTITE (42) 



SILVER GLANCE 



Silver sulphide, Ag 2 S. Isometric. 



Argentite, the black silver sulphide, is of widespread occurrence in 

 the silver mines of the central and southern portion of the State being 

 among the most important of the primary silver ore minerals. It 

 commonly takes the form of small disseminated grains and crusts 

 and is very rarely in distinct crystals. Many of the richer silver 

 ores consist of fine grained quartz containing argentite in grains so 

 minute that the mineral appears merely as a black stain in the 

 translucent quartz. Where it is in larger grains much of the argentite 

 assumes a mossy or furred dull black appearance upon short exposure 

 to the light and air. The mineral may be distinguished by its black 

 color and marked sectility when in masses of sufficient size, but the 

 identity of the very finely disseminated grains with argentite can 

 only be inferred. 



ADAMS COUNTY 



Argentite is reported to have been present in rich oxidized silver 

 ores formerly worked in the Ruthberg district, 18 miles north of 

 Salubria, where it was associated with cerusite, native silver, and 

 cerargyrite. 



«• D. C. Livingston. Univ. of Idaho School of Mines. Bull. 2, p. 41. 



«o D. C. Livingston and F. B. Laney. Idaho, Bur. Mines. Bull. 1, p. 100, 1920. 



*' D. C. Livingston and F. B. Laney. Idem, p. 66. 



* 3 D. C. Livingston and F. B. Laney. Idem, p. 34. 



