THE MINERALS OF IDAHO 469 



An analysis, in which the value for tungsten is low, was made and 

 gave the following results: 



Analysis of ) erbcrite from Camas County 



(E. V. Shannon, analyst) 



Per cent 



Silica (Si0 2 ) 1. 82 



Iron oxide (FeO) 22. 32 



Manganese oxide (MnO) 1. 69 



Tungsten trioxide (W0 3 ) 71. 88 



Molybdenum trioxide (Mo0 3 ) . 15 



Line (CaO) Trace. 



Magnesia (MgO) Trace. 



Total 97.86 



162 163 



Figs. 162-163.— Ferberite. Soldier, Camas County 



SCHEELITE (814) 



Calcium tungstate, CaO. W0 3 . Tetragonal. 



Scheelite is known from a number of localities in the State and 

 some production of tungsten ore has been made from the Coeur 

 d'Alene district in Shoshone County in which the tungsten was in this 

 form. 



BLAINE COUNTY 



Small quantities of scheelite are reported from the North Fork 

 mining district near Ketchum. 79 



BOUNDARY COUNTY 



Scheelite occurs in drusy crystalline quartz filling a fissure in 

 diorite near Copeland in Boundary County. The quartz contains 

 limonite-filled cavities and the scheelite is associated with this 

 limonite, some of it in coarse crystals, but most of it so finely divided 

 in the vein as to be shown only by the panning or analysis of 

 apparently barren material. 80 



» U. S. Geol. Survey, Useful Minerals of the United States, Bull. 624, p. 120, 1917. 

 8» D. C Livingston. Univ. of Idaho Sch. of Mines, Bull. 2, pp. 12-14, 1919. 



