to harden or become hardened by the deposition of calcium salts; the biological or geological process of calcification

calcium oxide, a chemical compound with the formula CaO, commonly known as quicklime

calcium phosphate (Ca3(PO4)2), an inorganic salt used in fertilizers and food additives

calcium hydroxide Ca(OH)2; slaked lime

calcium carbide CaC2

calcium phosphide (Ca3P2)

calcium bicarbonate Ca(HCO3)2

a type of limestone formed by the precipitation of calcium carbonate from mineral springs, including travertine

calcium content