limestone; sedimentary rock consisting mainly of calcium carbonate, used as a building material and for making lime and cement

A mineral primarily composed of calcium phosphate containing fluorine or chlorine; widely used as a source of phosphorus and in the production of fertilizers.

wollastonite, a calcium silicate mineral with the chemical formula CaSiO3

landscape characterized by soluble rocks such as limestone, often featuring caves and sinkholes

hydroxyapatite, a calcium phosphate mineral that is the main inorganic component of bone and teeth