What is Plaster of Paris ?
Plaster of Paris is basically a building material that consists of a fine, white-colored powder, known as calcium sulfate hemihydrate. The Egyptians, Greeks and Romans used Plaster of Paris for sculpting their tombs and other monuments, as well as for fireproofing in buildings. Plaster of Paris is obtained by heating gypsum or calcium sulfate dihydrate to about 140 - 180°C. When gypsum is heated to such a temperature, it loses three-quarters of its water content, leading to the formation of Plaster of Paris. The name Plaster of Paris is derived from the large deposits of gypsum in the Montmartre hill in Paris.