- Registry number
- CHEM-009
- Preferred designation
- Calcium sulfate dihydrate
- Common names
- Gypsum · selenite · satin spar
- Chemical formula
- CaSO₄·2H₂O
- CAS registry
- 10101-41-4
- PubChem CID
- 24928
- Formula mass
- 172.17 g/mol
- Class
- Hydrated sulfate mineral
Description & appearance
White to translucent mineral; can occur as large, well-formed crystals.
Occurrence & historical provenance
Forms in evaporite environments and sedimentary deposits. Gypsum is a major material in historical plasters and decorative work.
Established uses
Plaster and wallboard manufacture, soil amendment, and art conservation reference materials.
Hazards & handling context
Material dust and processing environment matter; raw mineral specimens may contain other minerals.
Important distinctions
Gypsum (dihydrate), hemihydrate plaster, and anhydrite are different hydration states.
Source ledger
The following reference records were consulted for chemical identity and general descriptive claims. Industrial grades, formulations, and mixtures may have different hazard profiles.
Catalogued 2026-11-11 · PyreArms 0.2.0. This is an authored reference entry, not a certificate of laboratory analysis.