The general term gypsum refers to two minerals, raw gypsum and anhydrite. Raw gypsum is calcium dihydrate (Ca [SO4] ·2H2O), also known as dihydrate gypsum or plaster. Anhydrite is anhydrous calcium sulphate. It is a very important industrial raw material that is widely used in construction, building materials, industrial and artistic models, chemical industry (sulfuric acid production, paper filler, paint filler), agriculture, food processing, pharmaceutical, and many other industries and applications.