Calcium Carbonate, Magnesium Carbonate, Potassium Carbonate and Zinc Carbonate are all salts of carbonic acid. All of these ingredients are white powders. These carbonate salts are used in bath products, makeup products, personal cleanliness products, shaving products, oral care products and skin and hair care products. - See more at: http://www.cosmeticsinfo.org/ingredient/magnesium-carbonate#sthash.OdtkmiJm.dpuf