This Specimen has been sold.
3.45" Water-Clear, Selenite Crystal - China
This is a nice, 3.45" long, water-clear selenite crystal collected from China. A faint phantom can be seen near one end of the crystal. There are similar specimens out of the Qinglong mine, however I'm not certain these selenite crystals come from this deposit.
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.