Apatite vs. Brushite — What's the Difference?

Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common endmembers is written as Ca10(PO4)6(OH,F,Cl)2, and the crystal unit cell formulae of the individual minerals are written as Ca10(PO4)6(OH)2, Ca10(PO4)6F2 and Ca10(PO4)6Cl2.

Brushite is a phosphate mineral with the chemical formula CaHPO4·2H2O. Crystals of the pure compound belong to the monoclinic space group C2/c and are colorless. It is the phosphate analogue of the arsenate pharmacolite.

Any of a group of natural, variously colored calcium phosphate minerals containing fluorine, chlorine, or hydroxyl. These compounds form hexagonal crystals and are components of bones and teeth, are a source of phosphorus for plants, and are used in the manufacture of fertilizers.

(mineral) A mineral formed by the interaction of guano with calcite and clay at a low pH, believed to be a precursor of apatite.

See fluorapatite.

A white or gray crystalline mineral consisting of the acid phosphate of calcium.

(mineral) A calcium fluoride phosphate of variable composition, sometimes used in the manufacture of fertilizer, as a gemstone, and (in powdered form) as a pigment.

Native phosphate of lime, occurring usually in six-sided prisms, color often pale green, transparent or translucent.

A common complex mineral consisting of calcium fluoride phosphate or calcium chloride phosphate; a source of phosphorus