Gypsum, one of the most widely used minerals in the world. Most gypsum in the United States is used to make wallboard for homes, offices, and commercial buildings. Gypsum is also used worldwide in concrete for highways, bridges, buildings, and many other structures that are part of our everyday life.

Gypsum is a non-metallic mineral, found in rock form. In absolutely pure form, gypsum is white. Impurities cause a change of color such as gray, brown, pink, or even almost black. Gypsum deposits were formed millions of years ago when salt water oceans covered most of the earth, and as they receded, many inland "dead" seas were formed which, as evaporation continued, became more and more salty. As those salts precipitated, they formed various compounds in turn, one of which was gypsum.