THE MINERALS OF IDAHO 181 



Valley County. — Chalcedonic silica replacing limestone forms the 

 principal gangue of the cinnabar deposits of the Yellow Pine quick- 

 silver district. 720 



/. JASPER 



Fine grained siliceous material heavily impregnated and colored 

 by iron oxides which may correctly be called jasper, occurs at a 

 number of places in Idaho. 



Custer County. — Jasper commonly occurs in the lavas in the same 

 areas which contain abundant chalcedony nodules, usually as veinlets 

 and stringers. In the Alder Creek (Mackay) district much of the 

 ore contains red and yellow ferrugineous jasper which is associated 

 with indefinite copper silicates allied to chrysocolla. Nodules of 

 brown jasper surrounded by crusts of chloropal have been sent to the 

 National Museum by D. C. L. Kirtley from Challis. 



Bear Lake County. — -The possibility of a new copper ore-jasper gem 

 or ornamental stone from the Humming Bird mine, in Paris Canyon, 

 near Montpelier, has been considered. The constituent minerals 

 are quartz with a very fine red dust pigment, and malachite. Under 

 the microscope the quartz is seen to be granular, with close fitting 

 grains, and is dusted full with minute red specks, probably hematite. 

 The malachite is in bright green grains and masses with a radial 

 fibrous and occasional spherulitic crystallization. The quartz 

 incloses numerous small grains or buhrs of malachite bristling with 

 needles. In the hand specimen the rock is bright jaspery red with 

 dark green splotches throughout. The quartz is close grained and 

 tough and takes a good polish. The malachite is softer though suffi- 

 ciently hard to be polished along with the quartz. The contrast 

 between the two colors is pleasing and for use in small ornaments, 

 scarf pins, brooches, etc.. the rock w T ould serve well. 73 



Blaine County. — Jasper of the usual red and brown colors is com- 

 mon in Tertiary lavas, having been especially noted in the area east 

 of Little Wood River near the southern boundary of the Hailey 

 topographic sheet. 



Fremont County. — A jaspery material forms the principal gangue 

 material in the ores of the Old Scott mine in the Skull Canyon district. 

 Specimens which have been examined show galena crystals up to 1 cm. 

 in diameter isolated in yellow to brownish-red jasper. 7 ' 



Washington County. — Jasper occurs as a gangue of manganese 

 ores on Snake River 20 miles below Huntington. 75 . 



"<■ E. S. Larsen and D. C. Livingston. U. S. Oeol. Survey, Bull. 715, pp. 73-83, 1920. 

 73 Douglas B. Sterrett. U. S. Geol. Survey, Mineral Resources 1909, pt. 2, p. 804. 

 " J. B. Umpleby. Prof. Paper, 97, U. S. Qcol. Survey, p. 119, 1917. 

 »« D. C. Livingston. Univ. of Idaho, vol. 14, Bull. 2, pp. 32-33, 1919. 



