apatite

ap·a·tite   (āp'ə-tīt')    n.  A natural, variously colored calcium fluoride phosphate, Ca5F(PO4)3, with chlorine, hydroxyl, or carbonate sometimes replacing the fluoride. It is a source of phosphorus for plants and is used in the manufacture of fertilizers. [From Greek apatē, deceit (from its often being mistaken for other minerals).]

Main Entry: ap·a·tite
Pronunciation: 'ap-&-"tIt
Function: noun
: any of a group of calcium phosphate minerals occurring variously ashexagonal crystals, as granular masses, or in fine-grained masses as the chief constituent of bones and teeth and of phosphate rock; especially : calcium phosphate fluorideCa₅F(PO₄)₃

apatite   (āp'ə-tīt')  Pronunciation Key  Any of several, usually green, transparent, hexagonal minerals consisting of calcium phosphate with either fluorine, hydroxyl, chlorine or carbonate. Apatite occurs in igneous, metamorphic, and sedimentary rocks, and is used as a source of phosphate for making fertilizers. Chemical formula: Ca5(PO4CO3)3(F,OH,Cl).