Apatite Gem

Gem apatite is the transparent, facet-grade form of apatite, a calcium phosphate that is the most abundant phosphate mineral and the material of bone and tooth enamel. Cut stones occur in a wide range of colours; the vivid neon blue-green 'Paraíba-like' apatite from Madagascar and Brazil and the violet-blue stones from Myanmar are especially prized.

Properties

Apatite is hexagonal and forms prismatic crystals, but it is comparatively soft (5 on the Mohs scale) — soft enough that it defines that point on the scale — which makes faceted apatite better suited to collectors and protected jewellery than to everyday rings. Some blue-green material is strongly pleochroic and may show a cat's-eye when cut as a cabochon.

Occurrence

Gem apatite comes from Brazil, Madagascar, Mexico, Myanmar and East Africa, forming in pegmatites, metamorphic rocks and carbonatites. It is the gem form of the species apatite.