Forms of Gypsum

Name/Chemical Formula Raw Gypsum
CaSO4 ・2H2O
Chemical Reaction ↓
Dehydration Reaction
↓
↑
Hydration Reaction
↑
Name/Chemical Formula Calcined Plaster / Hard Plaster
αCaSO4・1/2H2O
βCaSO4・1/2H2O
Calcined Plaster / Hard Plaster
αCaSO4・1/2H2O
βCaSO4・1/2H2O
Chemical Reaction ↓
Dehydration Reaction
↓
↑
Hydration Reaction
↑
Name/Chemical Formula Drying Plaster
ⅢCaSO4
Drying Plaster
ⅢCaSO4
Chemical Reaction ↓
Dehydration Reaction
↓
HydrationCaSO4・2H2O
↑
Name/Chemical Formula ⅡCaSO4 ⅡCaSO4
Chemical Reaction ↓
Dehydration Reaction
↓
↑
Hydration Reaction
↑
Name/Chemical Formula ⅠCaSO4 ⅠCaSO4