This Specimen has been sold.
3.8" Water-Clear, Selenite Crystal - China
This is a nice, 3.8" long, water-clear selenite crystal collected from China. One end of the crystals has a fishtail twin termination. 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.