Apatite (more precisely, Fluorapatite), fluorinated calcium phosphate, formula Ca5(PO4)3F.
Crystal system: Hexagonal
Density: 3.2 gms/cm3
Colour: Yellow, grey, blue-green, violet-blue or brown. Also colourless.
Streak: Colourless or white
Apatite is a generic name applied to three types of Apatite; Fluorapatite, Hydroxylapatite ((OH) replacing F) and Chlorapatite (Cl replacing F). A solid solution exists between all three end members. Apatite is a principal Phosphate ore and is widespread.
The largest known deposit of Apatite is Kirovsk in the Kola Peninsula, Russia,
The specimen shown is from Gav Valadare, Minas Gerais, Brazil.