THE MINERALS OF IDAHO 397 



IDAHO COUNTY 



Brown pitchlike masses of copper pitch occur surrounding chalco- 

 pyrite in quartz from the Tom Thumb claim, Lolo Creek mining dis- 

 trict. Similar black pitchlike material forms pseudomorphs after 

 masses of chalcopyrite in quartz from the Venture claim, Buffalo 

 Hump district. 



LATAH COUNTY 



Copper pitch occurs commonly with malachite, azurite, etc., in 

 oxidized copper ore of the Mizpah mine, Hoodoo district, in Latah 

 County. 8 



LEWIS COUNTY 



A little copper pitch occurs in copper stained quartz from the 

 Horseman mine, Deer Creek district. 9 



SHOSHONE COUNTY 



Copper pitch is one of the commonest secondary copper minerals 

 in the copper prospects of outlying sections of the Coeur d' Alene 

 district. It has been noted from many of the copper mines and 

 prospects in the vicinity of Mull an. It is usually the first product 

 from the breaking down, through oxidation, of chalcopyrite or 

 bornite and the chalcopyrite ores from shallow workings of the 

 prospects is almost invariably invested with an outer halo of pitch- 

 like brown material which penetrates it along cracks. 



Specimens from the Snowstorm mine show brown to black material 

 intimately associated with green chrysocolla, sometimes alternating 

 with the green material in concentric layers making up botryoidal 

 crusts. Fine large masses of dark brown material containing scat- 

 tered remnants of chalcopyrite have been obtained from the Rich- 

 mond shaft and similar specimens have been seen from almost all 

 of the copper prospects of the Mull an area. 



Copper pitch is almost invariably present also in association with 

 chalcopyrite, from which it has been derived, in ores from the numer- 

 ous copper prospects on the North Fork and Little North Fork of 

 the Coeur d' Alene River. 



CHLOROPAL (505) 



Hydrous ferric iron silicate, composition Earthy, amorphous to eryptocry.stal- 

 approximating Fe2O3.3SiO2.5H2O. line or fine micaceous. 



The name chloropal probably covers a number of related silicates 

 differing in composition, optical properties, etc. The most common 

 and best characterized of these is probably the one known as non- 

 tronite. The several Idaho occurrences mentioned below have not 



8 D. C. Livingston and F. B. Laney. Idaho Bur. Oeol. nod Mines, Bull. 1, p. 95. 

 8 Livingston and Laney. Idem, p. 100. 



