Formula: Ca5(PO4)3(Cl/F/OH)

Member of: Apatite Group > Apatite Supergroup

Name:The name (‘apatit’) was invented by A.G. Werner probably sometime in the mid-1780s, which he later described as being named from the Greek verb aπasάω (strictly ἀπasάω; transliterated as apatáō) as the derivation, which means ‘to deceive’ (someone) or ‘to be deceptive’, because, as he wrote, “until now it has misled all mineralogists in its identification.” (Roycroft & Cuypers, 2015).”Apatite” is a field term for unidentified calcium phosphate members of the apatite group.Most “apatite” is fluorapatite, whereas hydroxylapatite is much less common and chlorapatite is very rare.”Apatite” crystals are short to long hexagonal prisms; also thick tabular , frequently in the crystals of hydrothermal origin in pegmatites and veins, or low pyramids. Massive, coarse granular to compact. Globular or reniform at times with a sub-fibrous, scaly, or imperfectly columnar structure or as fibrous crusts; stalactitic; earthy; oolitic. May be rock-forming in beds of great extent; as nodular concretions in clays and shales; conglomeritic.