This Specimen has been sold.
2.6" Rosasite and Selenite Crystals - Hidden Treasure Mine, Utah
This colorful specimen contains deep blue-green colored, botryoidal rosasite formations, enshrouded in a thin layer of beautifully transparent selenite crystals. It was collected from the Hidden Treasure Mine in the Ophir District of Utah, a location that's well known for its zinc and copper mineral deposits.
Rosasite is a secondary mineral that forms in oxidation zones of copper-zinc deposits, generally forming a fibrous botryoidal sphere that can appear vitreous and silky. While typically featuring a blue-green color, colorless specimens are not unheard of. The chemical formula of rosasite is CuZnCO3(OH)2.
Selenite is a variety of gypsum, a soft sulfate mineral that is composed of calcium sulfate dihydrate (CaSO4 · H2O). When chemically pure, gypsum is transparent and colorless, however, impurities give the gypsum a diverse range of colors and formations. Desert rose, selenite and satin spar are just a few of the varieties of gypsum known to have formed though hydrothermal processes.