calcium sulfate
Noun: A white, odorless, crystalline or powdery inorganic compound with the chemical formula CaSO₄. It is a naturally occurring mineral salt found in various hydrated and anhydrous forms.
Calcium sulfate is used as a primary term in chemistry, geology, construction, and food science. It refers to the specific chemical compound itself. - It is commonly encountered as the dihydrate mineral gypsum (CaSO₄·2H₂O). - The anhydrous (water-free) form is known as the mineral anhydrite. - When partially dehydrated, it forms plaster of Paris (CaSO₄·0.5H₂O).
- Scientific/Industrial Context:
- Calcium sulfate is a common component of cement, where it controls the setting time.
- The laboratory prepared a pure sample of calcium sulfate for the experiment.
- Geological Context:
- This rock formation contains large deposits of calcium sulfate.
- Food Context:
- Calcium sulfate is used as a firming agent in tofu and a dough conditioner in some baked goods.
- "Calcium sulfate dihydrate": The specific term for the hydrated form containing two water molecules (gypsum).
- The statue was carved from a single block of calcium sulfate dihydrate.
- "Calcium sulfate hemihydrate": The specific term for plaster of Paris, containing half a water molecule per formula unit.
- The artist used calcium sulfate hemihydrate to make the mold.
- Gypsum (n): The common name for the dihydrate form of calcium sulfate (CaSO₄·2H₂O), a soft mineral.
- Anhydrite (n): The anhydrous (water-free) mineral form of calcium sulfate (CaSO₄).
- Plaster of Paris (n): The calcined (heated) hemihydrate form of gypsum, used for casts and molds.
- Gypsum (when referring specifically to the dihydrate mineral form).
- Terra alba (an old term sometimes used for purified forms, particularly in food applications).
The core meaning is the chemical compound CaSO₄. Its different physical forms (gypsum, anhydrite, plaster of Paris) are not synonyms for the compound itself but are specific manifestations or common names for its hydrated states. The term calcium sulfate is the general, technical name encompassing all these forms.
- a white salt (CaSO4)