Gypsum Wikipedia
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO 4 ·2H 2 O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and massive finegrained white or lightly tinted variety of gypsum, called alabaster, has been used for sculpture by many cultures including ...
