Benitoite... California state gem as of October 1985. Benitoite is one of the most rare and unique gems in the world. Gem quality benitoite has been mined from only one region in the world, the New Idria district of San Benito County, CA.
Stones are strongly dichroic, typically violetish blue and colorless. Exceptionally rare gemstones are colorless and pink. Benitoite is highly refractive, moderate birefringence, and strong dispersion (exceeding that of diamond in some directions) and comparible in appearance and price to fine sapphire and tanzanite.