Gypsum
Gypsum is an evaporite mineral most commonly found in stratified sedimentary deposits in association with halite, anhydrite, sulphur, calcite, and dolomite.
Gypsum is very similar to Anhydrite. The chemical difference is that gypsum contains two water and anhydrite is waterless. Gypsum is the most common sulfate mineral.
Gypsum uses include making cement board, plaster of Paris, soil amendment a hardening retarder in Portland cement. Gypsum varieties known as ‘satin’ and ‘alabaster’ are used for various ornamental purposes; however, their low hardness limits their durability.