Calcium carbonate precipitated; CaCO3; Molar mass 100.0869 g/mol Also known as calcite;??ragonite;??halk;??ime (material);??imestone;??arble;??yster;??earl It is a chemical compound used in agricultural lime and as an antacid. It is derived from a number of different rocks including ??imestone, ??halk, ??arble??nd??ravertine but these are just part of the calcium cycle. Coral polyps extract soluble calcium carbonate from the water and build reefs. Over millions of years these may be elevated to mountains and weathering return calcium carbonate back to the sea. Calcite, ??ragonite??nd??aterite??re pure calcium carbonate minerals.??any animals create structures like mollusc shells, pearls, egg shells and coral reefs. Both a decrease in temperature and an increase in pressure increases the solubility of calcium carbonate.