THE MINERALS OF IDAHO 



263 



showing divergent emerald-green transparent prisms in cavities in 

 limonite furnished measurable crystals, which supplied the data for 

 the drawing, Figure 70. The prisms present the usual habit, elon- 

 gated in the vertical direction and invariably twinned on the front 

 pinacoid a(100). These are always developed with the reentrant 

 angle up, as shown in the figure. The angles of the forms present, 

 a(100), 6(010), m(110), and c(001), agree well with the calculated 

 values. The prism zone is deeply striated vertically. 



LATAH COUNTY 



In the Hoodoo district malachite occurs as a constituent of oxidized 

 copper ore in the Mizpah and Copper King mines. A body of good 

 grade oxidized copper ore opened in the former 

 property in 1917 contained abundant malachite 

 with less azurite, native copper, cuprite, and copper 

 pitch ore. u 



LEMHI COUNTY 



In Lemhi County malachite is mentioned from a 

 large number of mines, 75 although no striking speci- 

 mens of the mineral have been seen from the 

 county. In the Blue Wing district malachite occurs 

 locally in the oxidized ores along with other oxida- 

 tion products of chalcopyrite in the veins which 

 produce hubnerite ores. In the McDevitt district 

 much malachite occurs, with a little azurite as an 

 oxidation derivative of bornite near the surface in 

 the Copper Queen mine. In the Carmen Creek 

 district malachite occurs in similar association and 

 similarly in the Queen of the Hills, John Torney, 

 and other mines of the Eureka district and in the 

 Blackbird district. 



LEWIS COUNTY 



Malachite occurs in oxidized ore of the Horseman property in the 

 Deer Creek district. 78 



SHOSHONE COUNTY 



In Shoshone County malachite is found in numerous places in the 

 Coeur d'Alene and tributary districts. In the southern copper area 

 malachite occurs in limonite in the Monitor, Richmond, and other 

 mines. In the Snowstorm mine malachite was found in much of the 

 oxidized ore as an impregnation in quartzite, but was probably 

 much less abundant than chrysocolla. Malachite occurs locally in 



Fig. 70. — M a l a - 

 chite. Cetstal 



TWINNED ON a 



(100). Weimer 

 mine, Kaufman 

 district, Fre- 

 mont County. 



u D. C. Livingston and F. B. Laney. Idaho Bur. Mines, and Oeol. Bull. 1, pp. 95-96, 1920. 



7 » J. B. Umpleby. U. S. Oeol. Survey, Bull. 528, pp. 110, 121, 157, 158, 1913. 



'• D. C Livingston and F. B. Laney. Idaho Bur. Mines and Geol. Bull. 1, p. 100, 1920. 



