Apatite is a very common mineral but transparent gemstone-quality is extremely rare. Despite the fact that is the defining mineral for 5 on Mohs scale of hardness, the gemstone remains virtually unknown to most, and is seldom found in jewelry stores. However, because apatite occurs in such a wide variety of attractive colors and forms, it is a favorite among gemstone collectors. The name ‘apatite’ was derived from a Greek word meaning ‘cheat’. It was given its name because of its close resemblance to several other gemstones that are often more valuable.
It is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite