Apatite
Image: Ringwoodit (CC BY-SA 4.0)
Mineral NameApatite
Chemical FormulaCa₅(PO₄)₃(F,Cl,OH)
Mohs Hardness5
Crystal Systemhexagonal
Lustervitreous
Streak Colorwhite
Cleavageimperfect on {0001} and {1010}
Fractureconchoidal to uneven
Specific Gravity3.18
Colorsgreen, blue, yellow, violet, pink, brown, colorless
Transparencytransparent to translucent
Type LocalityMinas Gerais (Brazil), Durango (Mexico), Ontario (Canada), Kola Peninsula (Russia), Maine (USA)
Mineral GroupPhosphates
Usesfertilizer production, gemstone, collector's mineral, source of phosphorus
Associated Mineralsquartz, feldspar, mica, amphibole, pyroxene, calcite
Raritycommon
Description
The image displays a dark, subhedral to euhedral hexagonal crystal of apatite in a thin section viewed under crossed polarizers. The crystal exhibits numerous internal fractures, appearing as bright white lines against the dark background, and is surrounded by a matrix of other minerals displaying vibrant, multi-colored interference patterns.
Geological Context
Apatite is a widespread accessory mineral found in various igneous rocks (e.g., granites, syenites, carbonatites), metamorphic rocks (e.g., gneisses, schists), and sedimentary rocks (e.g., phosphorites). It is also the main mineral in vertebrate bones and teeth.
