Dims: 2.6" x 2.3" x 2.1"(6.6 x 5.8 x 5.3 cm)
Wt: 5.31 oz.(150.6 g)
Gold Hill Mine, Tooele County, Utah, U.S.A.
A grass-green crust of Conichalcite rests on this Utah specimen. It has no definite crystal form, a dull luster, and an indeterminate translucence. Its habit has botryoidal tendencies. This crust rests on a thick layer of halloysite, an aluminum silicate hydroxide and member of the kaolinite group. I believe that there may be some other copper phosphate minerals in this specimen, or maybe some chrysocolla, but I cannot be sure. The base rock looks like a pale brown shale or mudstone, and has veins of a bright green-blue mineral running through it for short distances. This is a very pretty and mysterious mineral specimen that I will have to study a bit.