This is a beautiful yellow selenite crystal aggregation that was collected from Peru. The crystals are highly fluorescent under short wave UV and emit phosphorescent light that remains several seconds after the UV light is turned off.
These crystals only form in conditions where mineral rich water containing selenite forming minerals (calcium & sulfur), evaporates. Every crystal is unique, just like a snowflake. Typically these crystals are found 3-6 meters underground requiring substantial excavation work.
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.