THE MINERALS OF IDAHO 

 BINGHAM COUNTY 



317 



A sand from Rosa, Bingham County, which is concentrated from 

 a Snake River placer, contains numbers of beautifully sharp color- 

 less prismatic zircon crystals. A few of the zircons of this sand are 

 brown to red-brown in color. Most of these show the prism ra(110) 

 and the pyramids p(lll) and ?/ (331), developed as shown in Figure 91. 



84 



M 



85 89 91 86 



Figs. 83-91.— Zircon crystals out of black sands from Boise and Minidoka Counties 



BOISE COUNTY 



Zircon, in the usual highly perfect and colorless crystals, is abundant 

 in every placer concentrate from Boise County which has been ex- 

 amined. It is invariably associated with the monazite. In form 



