PubChem Notes:

Calcium Sulfate A calcium salt that is used for a variety of purposes including: building materials, as a desiccant, in dentistry as an impression material, cast, or die, and in medicine for immobilizing casts and as a tablet excipient. It exists in various forms and states of hydration. Plaster of Paris is a mixture of powdered and heat-treated gypsum.

Gypsum - definition from

[(Science: chemical) a mineral consisting of the hydrous sulphate of lime (calcium). When calcined, it forms plaster of paris. selenite is a transparent, crystalline variety; alabaster, a fine, white, massive variety. Origin: L. gypsum, gr.; cf. ar. jibs plaster, mortar, Per. Jabsn lime. Its chemical formula is CaSO4•2H2O.

MediLexicon gypsum - Medical Dictionary Definition for Term 'gypsum'

[1. The natural hydrated form of calcium sulfate; a component of the stones, plasters, and investments used in dentistry.

Molecular Formula: CaH4O6S

InChI: InChI=1/Ca.H2O4S.2H2O/c;1-5(2,3)4;;/h;(H2,1,2,3,4);2*1H2/q+2;;;/p-2/fCa.O4S.2H2O/qm;-2;;

SMILES: [Ca++].[H]O[H].[H]O[H].[O-]S([O-])(=O)=O

    Calcium sulfate dihydrate
    calcium sulfate dihydrate
    calcium sulfate--water (1/2)

    PubChem CID 24928
    ChEBI 32583
    PubChem ID 11533923