A common location for gypsum, an evaporite mineral, is layered sedimentary deposits with the minerals halite, anhydrite, sulphur, calcite, and dolomite. Anhydrite and gypsum (CaSO4.2H2O) are quite similar (CaSO4). Gypsum and anhydrite are different chemically in that gypsum includes two fluids while anhydrite does not. The most typical sulphate mineral is gypsum.
The production of wallboard, cement, plaster of Paris, soil conditioning, and use as a hardening retarder in portland cement are all examples of uses for gypsum. Gypsum varieties such as "satin spar" and "alabaster" are utilised for a variety of decorative uses, but their endurance is constrained by their low hardness.