THE MINERALS OF IDAHO 423 



sect the ore body a small vein was encountered not far from the portal 

 in which the lead was all in the form of pyromorphite in greenish- 

 yellow masses and small drusy crystals. A short raise was driven on 

 this vein and from a small stope which was opened some 30 tons of 

 pyromorphite were shipped as ore. Some pyromorphite was en- 

 countered elsewhere in seams in the walls of this tunnel. 



Pyromorphite was also found abundantly as crusts and druses in 

 the Quaker tunnel, opened for litigation purposes by the Bunker 

 Hill Co., above the Arizona railroad grade and west of the upper 

 workings of the Senator Stewart mine on the same slope. 



This mineral has been found on the outcrop of the Northern Light 

 mine on Pine Creek as pale-green crystals in cavities in quartz seams 

 in slate. 



The Lookout Mountain mine, on the high mountain east of the 

 forks of Pine Creek, has recently produced some very line specimens 

 of pyromorphite. A large green crystal from this locality is illus- 

 trated in Plate 17. Specimens from the outcrop of the vein con- 

 tained numerous colorless crystals of pyromorphite and other speci- 

 mens from the vein show prismatic crystals, some of which have 

 narrow faces of the second order prism, on quartz. 



The Sierra Nevada mine in Deadwood Gulch has encountered pyro- 

 morphite in places in the flat oxidized vein which is now exhausted. 

 During the operation of this mine under the Peoples lease in 1914, 

 good specimens of small yellow-green stout prisms and larger barrel- 

 shaped bulging deep olive-green crystals coating quartzite were ob- 

 tained in the Clark winze. 



Pyromorphite has been reported from the Hypotheek mine in 

 French Gulch south of Kingston, although no specimens from this 

 mine have been seen by the writer. 



This mineral probably occurs elsewhere in the district and a mod- 

 erate number of good specimens can probably still be obtained in a 

 number of places. 



MIMETITE (551) 

 Chlor-arsenate of lead, 



9Pb0.3As 2 5 .PbCl 2 . Hexagonal. 



Mimetite the arsenic analogue of the more common pyromorphite 

 appears from available records to be a rare mineral in Idaho. Only 

 two localities have been mentioned. 



BLAINE COUNTY 



Mimetite or "arsenicite of lead" is reported to occur in the Wood 

 River district. 27 



» Mint Report 1881, p. 179, quoted by WaldemarLindgren. U. S.Geol. Survey, 20th Ann. Rept.,pt.3, 

 p. 213, 1900. 



