Factsheet on: What is Gypsum?
C. Processing Natural Gypsum When Gypsum ( CaSO 4,2H 2O) is ground to a powder and heated at 150° to 165° C, threequarters of its combined water is removed producing hemihydrate plaster ( CaSO 4,1/2H 2O), commonly known as the ''Plaster of Paris''. When this powder is .