Calcium Sulphate

Calcium sulphate is an inorganic white solid with the formula CaSO4. It occurs naturally as a mineral and is also produced synthetically, often as a by-product (e.g. from desulphurisation). The compound exists in three levels of hydration: anhydrous (as mineral anhydrite), dihydrate (gypsum or as mineral selenite) and hemihydrate (Bassanite or plaster of Paris).All forms are poorly soluble in water and cause permanent hardness in water.

Gypsum, E516, Plaster of Paris, Anhydrite, Selenite, Alabaster
Chemical Formula
CAS Number
7778-18-9 (anhydrous), 10034-76-1 (hemihydrate), 10101-41-4 (dihydrate)


Molar Weight
172.17 g/mol (dihydrate)
Melting Point
1,460°C (anhydrous)
Flash Point
non flammable
2.32 g/cm³ (dihydrate)
Powder, White, Solid

Uses and Applications

Key applications

  • Food additive
  • Oil and Gas
  • Agricultural
  • Pharmaceuticals
  • Animal feed
  • Cosmetic products
  • Building & Construction products


  • Pharma
  • Energy Services
  • CASE & Construction
  • Beauty & Personal Care
  • Food & Nutrition
  • Animal Nutrition
  • Agriculture