Updated: May 18, 2020
Chemical Composition: BaTiSi3O9
Benitoite is an extremely rare blue barium titanium cyclosilicate, and found in hydrothermally altered serpentinite. It was discovered in 1907 by prospector James M. Couch in the San Benito Mountains, California, that’s how its name was derived. In 1985 benitoite was named as the official state gem of California.
The color ranges from colorless to violetish-blue. Benitoite has very high dispersion due to its high refractive index, 1.804. Occasionally, red and green flashes can be seen but at times it is masked by its dark body hue.
蓝锥矿是一种极其稀有的蓝色钡钛环硅酸盐，存在于热液蚀变的蛇纹石中。 1907年，探矿者James M. Couch在加利福尼亚州圣贝尼托山发现了它，这就是它的名字的来源。 1985年，蓝锥矿被命名为加利福尼亚州的官方宝石。
蓝锥矿的颜色范围可以从无色到紫蓝色。 由于其高折射率1.804使它具有非常高的色散。 有时可以看到红色和绿色的闪光，但有时会被其自身的暗色所掩盖。
Although the biggest gem quality benitoite cut weighs over 7ct, but majority weigh lesser than 1.5ct. Common size 0.5ct due to its flat, triangular and small rough. It fluorescents a blue to bluish-white colour under short wave ultraviolet light.
Though there are several small-scale deposits of benitoite worldwide, the only deposit capable of producing gem quality material is at the Southern tip of San Benito County, California. This deposit unfortunately has ceased its operations in 2005, thereby adding to the scarcity of this gemstone, leading to a higher demand. No wonder it has been name as the top 10 rarest gemstones in the world.
尽管世界范围内有几处蓝锥矿小规模的矿床，但唯一能够生产宝石品质的矿床位于加利福尼亚州圣贝尼托县的南端。 不幸的是，该矿床于2005年停止了运营，从而加剧了这种宝石的稀缺性，导致需求量增加。 难怪它被誉为全球十大最稀有的宝石。