Explanation:
calcium sulfate dihydrate
Gypsum is the name given to a mineral categorized as calcium sulfate mineral, and its chemical formula is calcium sulfate dihydrate, CaSO4⋅ 2H2O. However, a broader definition includes all the calcium sulfates, including calcium sulfate hemihydrate, CaSO4⋅ 0.5H2O, which is known as plaster or plaster of Paris (POP).