Calcium carbonate is an inorganic compound, commonly known as lime, limestone, marble and so on. The chemical formula is CaCO₃, neutral, basically insoluble in water, soluble in hydrochloric acid. It is a common substance on the earth. It exists in aragonite, calcite, chalk, limestone, marble, limestone and other rocks. It is also the main component of animal skeleton or shell. Calcium carbonate is formed by the combination of calcium ions and carbonate ions. Therefore, calcium carbonate is also carbonate. Calcium carbonate is divided into two categories: heavy calcium carbonate and light calcium carbonate. Heavy calcium carbonate and light calcium carbonate react differently because of their different particle size, crystal shape and interfacial properties. For this reason, active calcium carbonate, papermaking calcium carbonate, plastics calcium carbonate, nanometer calcium carbonate, edible calcium carbonate, medicinal calcium carbonate, chemical calcium carbonate, coating carbonate are also extended. Calcium and many other varieties and different uses of calcium carbonate varieties.