Was California’s official state gemstone discovered in San Benito County, California?

The official California state gemstone is benitoite, which was discovered in 1907 near the San Benito River at the Benitoite Gem mine in the New Idria district of San Benito County. It has been the state gemstone since 1985. 

Benitoite is considered one of the rarest gemstones in the world and is primarily a collectors item.

The only known locations which produce gem-quality benitoite are the Benitoite Gem mine and the Junnila claim in San Benito County, though small quantities have also been found in other New Idria district mines in San Benito County, as well as in Fresno County, Arkansas, Japan and Australia. The Benitoite Gem mine is the world’s only commercial source for gem benitoite. 

Benitoite, named for the location where it was discovered, is a barium titanium silicate mineral that is known to occur as medium blue/violet crystals, but also range from colorless to dark blue.