Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, and chlorapatite, with the chemical formula Ca₅(PO₄)₃(F,Cl,OH). It occurs in a wide range of colors, including green, blue, yellow, and violet.
- Formula: Ca₅(PO₄)₃(F,Cl,OH)
- Crystal system: Hexagonal
- Hardness: 5 on Mohs scale
- Luster: Vitreous
- Transparency: Transparent to translucent
- Colors: Green, blue, yellow, brown, violet