THE MINERALS OF IDAHO 187 



VALENTINITE (216) 



Antimony trioxide, Sb 2 3 . Orthorhom. 



SHOSHONE COUNTY 



The antimony oxide valentinite occurs sparingly in the ores of 

 the Stanley antimony mine in Gorge Gulch above Burke in the 

 Coeur d'Alene district in the form of drusy coatings and crusts 

 on stibnite and quartz. Although these crusts are very thin they 

 often cover several square inches of surface. Those which rest 

 on quartz are pale brown in color while the ones on stibnite are 

 usually olive green. The luster is waxy and the mineral looks like 

 cerargyrite or embolite. Valentinite may also occur in the earthy 

 oxidation products which are common near the outcrops of the 

 Coeur d'Alene antimony and other antimony veins on Pine Creek. 



MOLYBDITE 



Hydrous ferric molybdate, Fe20 3 .3Mo0 3 .73^H 2 0. Orthorhombic. 



ADAMS COUNTY 



Molybdite has been reported from the Peacock claim, Seven 

 Devils district, where it occurred as an olive green earthy substance 

 associated with powellite in a specimen consisting mainly of garnet 

 and bornite. 88 Livingston and Laney 89 state that molybdite occurs 

 sparingly in the contact metamorphic copper ores as an alteration 

 product of molybdenite. Melville regarded the molybdite associated 

 with the powellite as secondary after the calcium molybdate and 

 derived from it by the action of carbonated waters. 



BOUNDARY COUNTY 



Molybdite is abundant in good specimens as thick silky pale yellow 

 films and crusts coating quartz which contains molybdenite from 

 veins in granite 21 miles by trail southwest of Porthill. Specimens 

 of this material were shown the writer by Frank L. Hess, of the 

 United States Geological Survey. 



CUSTER COUNTY 



A little molybdite has been noted as a yellow ocherous stain 

 associated with molybdenite and powellite in quartz in specimens 

 reported to be from the Bay Horse district. 



ELMORE COUNTY 



Bright yellow molybdite occurs as an alteration product of molyb- 

 denite on granite in a specimen sent to the National Museum by 

 William R. Decker from Pine, Elmore County. 



•» W. H. Melville. Amer. Jour. Sci., vol. 41, p. 138, 1891. 



•» D. C Livingston and F. B. Laney. Idaho Bur. Geology and Mines, Bull. 1, p. 67, 1920. 



