2.5" Selenite Crystal - Kansas

Selenite is a variety of gypsum, a soft sulfate mineral composed of calcium sulfate dihydrate (CaSO4 · H2O). When chemically pure, gypsum is transparent and colorless, but 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.