Selenite

Selenite is a transparent crystal habit variety of the mineral gypsum. Like all kinds of gypsum, it is made up of calcium sulfate dihydrate (having two molecules of water) and has the chemical formula CaSO4·2H2O. Its name comes from the Greek term selene meaning “moon” because people believed that the crystal waxed and waned like…

Selenite is a variety of the mineral gypsum, composed of calcium sulfate dihydrate (CaSO4·2H2O). The term selenite comes from the Greek selene for “moon”, referring to the stone’s pearly lustre on cleavage surfaces. Some of the largest crystals found in the world are selenite, with specimens in the Cave of the Crystals being over 12…