a white powder or colorless, crystalline compound, CaCO, found mainly in limestone, marble, and chalk, as calcite, aragonite, etc., and in bones, teeth, shells, and plant ash: it is used in making lime, paints, plastics, etc.
"calcium carbonate." YourDictionary, n.d. Web. 12 October 2018. <http://www.yourdictionary.com/calcium-carbonate>.
calcium carbonate. (n.d.). Retrieved October 12th, 2018, from http://www.yourdictionary.com/calcium-carbonate
A colorless or white crystalline compound, CaCO3, occurring naturally as chalk, limestone, marble, and other forms and used in a wide variety of manufactured products including commercial chalk, Portland cement, medicines, and dentifrices.