Selenite, gypsum, or alabaster, is a calcium mineral with the chemical formula CaSO4.2H2O (calcium dihydrate sulfate). Selenite when baked and mixed with water becomes solid.
Selenite sculptures are known from ancient Egypt.
Selenite is commonly found in sedimentary rocks and hydrothermal deposits.
The dense fine-grained gypsum is called Alabaster.
The fibrous variety of gypsum with the characteristic moving highlights is called Selenite in European countries and Satin Spar in the USA.
Selenite is a great semi-precious stone.