444 BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



OWYHEE COUNTY 



Barite has been found in the De Lamar mine in small bunches in 

 kaolin in the Silver City district. 49 On one large nodular mass of 

 naumannite previously described from this mine a small cavity was 

 lined with minute tabular crystals of barite. These had the form 

 and habit shown in Figure 145, the forms being c(001) and ra(HO) 

 with smaller faces of a(100), (210), and Z(104). The identity of the 

 material was established by both crystallographic and optical meas- 

 urements. 



SHOSHONE COUNTY 



Barite has been found at a number of places in the Coeur d'Alene 

 district. In the Mullan area it occurs in several mines, among them 

 the Morning, Gold Hunter, Carney Copper, Little Giant, and prob- 

 ably others. In places in the Gold Hunter mine barite is abundant 

 in fine-granular white masses carrying thin sheets of galena, sphal- 

 erite, and tetrahedrite, which give the ore a striking banded appear- 

 ance. More coarsely ciystalline barite was found in some of the 

 upper workings, and the mineral occurs in seams in the country rock. 



In the Carney Copper mine barite occurs as veins in places 4 feet 

 wide. It is fine grained and commonly shows banded structure 

 with the development of small pyrite crystals. 



In the Morning mine barite occurs locally in irregular bands which 

 may be 1 foot thick. 



Barite and galena occur in the Little Giant prospect south of 

 Mullan on Silver Creek. 



Barium has been reported to have been found by analysis in ores 

 from the Standard-Mammoth mine, although no specimens of barite 

 have been seen from this mine. 



Barite has been found in occasional masses in several of the lead- 

 silver mines east of Wardner. This mineral formed a small vein 

 with galena in the Senator Stewart mine and has been reported to 

 have been found in the Crown Point and Silver King mines in Gov- 

 ernment Gulch. In the Caledonia mine a large mass of coarse- 

 cleavable white barite was encountered in a tetrahedrite ore-shoot 

 on the first floor above the 900 foot level in 1915. 



ANGLESITE (721) 

 Lead sulphate, PbS0 4 . Orthorhombic. 



Angelsite is usually the first mineral formed by the breaking down 

 of galena under the influence of oxidation. It very frequently occurs 

 surrounding lumps of galena or inserted betw r een the core of parent 

 galena and an outer crust of cerusite. Such anglesite is usually 

 fine compact massive and has a characteristic ashy gray color. The 

 mineral more rarely occurs as transparent glassy crystals which 



« Waldemar Lindgren. U. S. Qeol. Survey, 20th Ann. Rept., pt. 3, p. 170, 1000. 



