GYPSUM

Gypsum, the common name for the mineral calcium sulfate, with chemical formula of CaSO4, bonds easily with water and is usually found in its natural state as hydrated calcium sulfate. It is a soft mineral rock that mainly appears in white or gray color and is composed of translucent crystals. Naturally occurring gypsum is composed of calcium, sulfur, oxygen and hydrogen. Gypsum is the most common sulfate mineral.