Description | Apatite, Ca5(PO4)3(OH,F,Cl) is the most common phosphate mineral. It is present in many rocks of different sorts but is generally too fine grained and disseminated to be seen easily. It sometimes forms in massive beds (phosphorites) which are mined to manufacture fertilizers and other chemicals. Well-formed apatite crystals are hexagonal prisms, but the 6 cm long samples shown here are subhedral (poor crystals) and highly fractured. |