THE MINERALS OF IDAHO 



253 



cent and steel-gray in color with metallic luster from thin outer 

 coatings of manganese oxide. Other pure white masses of crystals 

 were crusted with dendritic wires and moss-like masses of native 

 silver. Some specimens, yellow from a thin outer coating of limonite, 

 were made up of small model per- 

 fect six-rayed penetration twins. 

 Workings of the Bunker Hill Co., 

 penetrating the oxidized portion of 

 the Tyler vein from below about 

 this time disclosed fine cerusite, par- 

 ticularly in the Barney stope. Two 

 stalactitic masses having a large 

 botryoidal form were taken from 

 this stope in 1915. These weighed 

 nearly 100 pounds, were coated out- 

 side with limonite, but inside they 

 consisted of pure white cerusite of 

 fibrous structure. These were em- 

 bedded in the concrete of the bridge 

 crossing the flume on McKinley Ave- 

 nue in the town of Kellogg. A large 

 specimen of fibrous cerusite from this 

 stope which laid for some years on 

 the floor of a storeroom of the old 

 Bunker Hill office at Kellogg con- 

 tained included unoxidized masses 

 of resinous brown sphalerite. 



The Caledonia mine, opened 

 through a shaft to the 300 and 500 

 foot levels, west of Wardner and on 

 the east of Deadwood Gulch, in 1910 

 developed a rich body of carbonate 

 ore and produced much cerusite 

 prior to 1915 and yielded many 

 excellent specimens, but much of 

 the cerusite was massive and the 

 yield of fine specimens was much 

 smaller, in proportion, than in some fig. 62. 

 other mines of the district. Some 

 small clear glassy crystals were al- 

 ways to be obtained and a few large glassy twins in considerable 

 aggregates were obtained embedded in clayey gouge. The usual 

 columnar and " taffy-like" fibrous white specimens were obtained, 

 sometimes colored green by an outer layer of malachite. Some 

 small colorless to slightly smoky crystals obtained from cavities 



Cerusite. Characteristic group 

 twinned on to (110). mammoth mine, 

 Mace, Shoshone County 



