Apatite

Apatite is a gemstone group of phosphate minerals. Apatite can be found in many colors, as such often confused with other gemstones such as beryl. Primarily found in the flourapatite variety, the group occurs in volume in most igneous rock during formation as microscopic crycstals. It is used as the benchmark on the Mohs scale for the Hardness value of 5. Apatite rocks have been found to contain rare earth metals and used as safe ores, and are discovered in moon rocks..
Chemical Formula CA5(PO4)3(F,Cl,OH)
Color White, yellow, colorless, brown, gray, pink, blue, green
Hardness 5.0
Crystal System Hexagonal
Refractive Index 1.628 Â -Â 1.649
SG 3.1 Â -Â 3.2
Transparency Transparent to translucent
Double Refraction 0.001 - 0.007
Luster Vitreous
Cleavage indiscernible
Mineral Class Apatite