Gypsum Powder is widely utilized in construction industry for finishing walls & ceilings. It also finds application in block form for large building constructions. This powder comprises calcium sulfate dehydrate having molecular formula CaSO4.2H2O with white colored powdery appearance. It is also utilized as fertilizer and forms a main component in plaster, chalk, &wallboard. Gypsum Powder shows retrograde solubility in water with specific gravity of 2.31 to 2.33. It produces vitreous silky appearance to walls and has hardness level of 2 on Mohs scale. In Portland cement, it acts as hardening retarder.