ETYM Greek, deceit, from apate deceit; it was often mistaken for other minerals.
Common calcium phosphate mineral, Ca5(PO4)3(F,OH,Cl). Apatite has a hexagonal structure and occurs widely in igneous rocks, such as pegmatite, and in contact metamorphic rocks, such as marbles. It is used in the manufacture of fertilizer and as a source of phosphorus. Apatite is the chief constituent of tooth enamel while hydroxyapatite, Ca5(PO4)3(OH)2, is the chief inorganic constituent of bone marrow. Apatite ranks 5 on the Mohs’ scale of hardness.
A common complex mineral consisting of calcium fluoride phosphate or calcium chloride phosphate; a source of phosphorus.