Gypsum is a sulfate mineral composed of calcium sulfate dehydrate, CaSO4.2H2O. It is soft, widely mined and used as the main constituent in many forms of plaster, blackboard chalk and fertilizer. Naturally occurring gypsum is composed of calcium, sulfur, oxygen and hydrogen.
The most common uses of gypsum powder are in building materials. For centuries, Gypsum has been used to decorative elements for buildings. Pure white rock gypsum has been used in making carved statues and sculptures.
Nowadays almost all modern homes and buildings use gypsum in the form of wall board, also known as gypsum board, drywall or sheet rock. Americans homes typically contain tons of gypsum in the form of drywall. It is attached to wooden framing to make walls and ceilings. Gypsum powder mixed with water becomes hardened and rock-like when dried. The hardened gypsum is pressed between sheets of paper to form slabs of drywall which makes an inexpensive building material that can easily be cut in to size. It provides a sound barrier and is resistant to fire.