Calcium Carbonate (CaCO₃) is a white, odorless, tasteless powder or crystalline compound found naturally in rocks like limestone, marble, and chalk. It is widely used in industries such as plastics, paints, paper, rubber, ceramics, and construction as a filler material. In its purified form, it’s used in pharmaceuticals (as an antacid or calcium supplement) and food products. Calcium carbonate is insoluble in water but reacts with acids to release carbon dioxide, making it useful in acid neutralization and environmental applications like flue gas treatment and water softening.