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Which minerals contain calcium sulfate?

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Calcium sulfate (CaSO4) is a naturally occurring salt that is primarily found in the following minerals:

  • Gypsum: This is the hydrated form of calcium sulfate (CaSO4·2H2O). It is a common sulfate mineral of significant commercial importance, often found in sedimentary formations and associated with other evaporite minerals.12
  • Anhydrite: This is the anhydrous form of calcium sulfate (CaSO4), meaning it contains no water of crystallization. It is a major rock-forming mineral frequently found in association with gypsum in evaporite deposits.3

Additionally, plaster of paris is a hemihydrate form of calcium sulfate (CaSO4·12H2O) produced by heating gypsum.42