Apatite is little know outside the gem collector market, yet deserves wider recognition. It comes a variety of brilliant colors, with the more desirable being a bright greenish blue, like this gem. The refractive index and dispersion are similar to topaz, but its softer. Because of its softness and sensitivity to heat/thermal shock apatite must be treated with care when set in jewelry and is best suited for occasional wear.
This gorgeous brilliant blue0green apatite comes from Madagascar, which is famed for its intense blue-green apatite. The color is developed by heating deep green, nearly black apatite. The treatment is permanent and stable. I cut this apatite in my “Hyperbola” brilliant oval design, tweaked slightly for the optical characteristics of this gem material. The gem weighs 2.20 carats and measures 8.1 x 6.9 x 5.7 mm.