468 



BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



from a filled fissure in quartzite which is traceable for over 1,000 feet. 

 The vein filling is drusy white quartz and many small unfilled spaces 

 occur between the quartz grains and crystals. The minerals in the 

 quartz are hubnerite, tetrahedrite, galena, sphalerite, pyrite, and 

 molybdenite, apparently all contemporaneous. Other veins occur 

 but are smaller and less persistent than the main vein. The tetra- 

 hedrite is argentiferous and the mine was formerly worked for silver. 77 

 The hubnerite occurs in large brown blades embedded in the quarts. 

 These have a bronzy luster and distinct cleavage. Some of them are 

 6 or 7 cm. in length. The following analyses of hubnerite from this 

 locality have been made. 



Analyses oj hubnerite from Lemhi County 



Tungsten trioxide (WO3)- 

 Manganese oxide (MnO). 

 Ferrous oxide (FeO) 



Total. 



W. T. 



Schaller 1 



76.60 



21.40 



2.00 



100.00 



J. E. 

 Talmadge s 



75.94 



21.57 



2.38 



1 U. S. Geol. Survey Bull. 591, p. 365, 1915. 



s F. L. Hess. U. S. Geol. Survey Bull. 583, p. 24, 1914. 



A third analysis by the writer (E. V. S.) gave practically identical 

 results. 



FERBERITE (813 b) 



Iron tungstate, FeO.W0 3 . Monoclinicv 



The only locality for the iron end member of the wolframite series 

 thus far known in Idaho is in Camas County. 



CAMAS COUNTY 



Ferberite occurs in 3 narrow parallel quartz veins 1 to 10 cm, 

 wide and about 50 cm. apart in trachyte or syenite porphyry on 

 Corral Creek near Soldier Mountain in Camas County. The rock 

 is light colored with prominent white phenocrysts which are com- 

 pletely kaolinized in the vicinity of the mine. 78 The ferberite fills 

 fractures in the brecciated rock and occurs as drusy crystals lining 

 open spaces producing specimens which greatly resemble those from 

 the Boulder County, Colo., field. The larger crystals are striated 

 and rounded while the smaller are combinations of the base c(001), 

 the dome n(401), and the pinacoid &(010), as illustrated in Figure 163. 

 They are elongated on the a axis. Some of them have notched ends 

 and appear to be twinned on c(001) as illustrated in Figure 162- 

 The crystals are coated with limonite but are dead black in color. 



" D. C. Livingston. Idaho School of Mines, Bull. 2, pp. 22-25, 1919. 



"8 D. C . Livingston . Univ. of Idaho School of Mines Bulletin, vol. 14, No. 2, pp. 25-26, 1919. 



