THE MINERALS OF IDAHO 193 



chrysocolla mixed with it and is in such small amounts that a careful 

 chemical examination was not attempted. 96 



LEMHI COUNTY 



Some melaconite is reported to occur in the oxidized ore of the 

 Copper King mine, Eureka district. 



SHOSHONE COUNTY 



Earthy to compact and waxy-lustered black material which was 

 common in the oxidized ores of the upper levels of the Caledonia mine 

 may have been all or in part melaconite. 



WASHINGTON AND ADAMS COUNTIES 



Melaconite has often been reported from the various copper mines 



of the Seven Devils district. Livingston and Laney 97 state that it 



is third in order of importance in the oxidized ores, although they 



place a question mark after the identification of the mineral. 



Numerous specimens from this district preserved in the National 



Museum labeled melaconite, contain a dense waxy black opaque 



material. A small sample of this material upon analysis proved to be 



an impure hydrated copper silicate. The analysis is given under 



1 ' melanochalcite. ' ' 



CORUNDUM (231) 



Aluminium oxide, A1 2 3 . Hexagonal, rhombohedral. 



Corundum has been reported from a number of localities in Idaho, 

 always in loose gravel mined for gold. The mineral has in no instance 

 been found in its original matrix. 



BOISE COUNTY 



Corundum has been reported to occur in heavy concentrates from 

 gold placers on Gold Fork and other tributaries to Payette River. 



CLEARWATER COUNTY 



Various shades of blue and green sapphire have been reported to 

 occur in gravel deposits near Pierce in Clearwater County, especially 

 along Rhodes and Oro Fino Creeks. A large lot of the material 

 picked from a placer concentrate from near Pierce (Cat. No. 87504 

 U.S.N.M.), consists of pebbles and rough worn crystals up to 2 cm. 

 in greatest diameter. These vary greatly in color, ranging from deep 

 blue through pale blue to greenish, chatoyant blue and opaque 

 gray. Some have a sapphire blue core in a grayish to greenish shell. 

 A few are pale grayish pink. Gray dull material greatly predomi- 

 nates. None of the material approaches gem quality. The crystals 



•« J. B. Umpleby. U. S. Qeol. Surv., Prof. Paper, 97, pp. 54-55, 1917. 



87 I). C. Livingston and F. B. Laney. Idaho Bur. Mines and Qeol., Bull. 1, p. 07, 1920. 



."4347— 26t 14 



