Calcium carbonate is an inorganic compound with calcium carbonate formula CaCO3 and a molar mass of 100.09 g/mol. It is a white crystalline powder composed of calcium carbonate crystals that decompose at high temperatures releasing carbon dioxide. Pure calcium carbonate is odorless, tasteless, and stable at room temperature. The density of calcium carbonate is 2.71 g/cm3. Calcium carbonate in water is alkaline with a pH value greater than 7. The powder is less soluble in water but soluble in acids. Calcium carbonate exists in various forms such as heavy calcium carbonate, light calcium carbonate, and nano calcium carbonate. Calcium carbonate is widely used in industry and daily life. It is used as a filler, reinforcing agent and regulator in food, rubber and plastics, paper making, paint, printing ink, medicine and other industries. In addition, calcium carbonate is also used as a soil conditioner, water treatment agent and building material.