Benitoite from the Benitoite Gem Mine in San Benito County, California, the type locality.  Ben

Benitoite from the Benitoite Gem Mine in San Benito County, California, the type locality.  Benitoite is a rare blue barium titanium silicate mineral and is considered to be one of the rarest minerals/gemstones in the world.  It was discovered in 1907 and is the State Gemstone of California.  According to www.minerals.net, “The crystal structure of Benitoite is unique, and is the only significant mineral in its crystal class. It crystallizes in a rare hexagonal sub-class called ditrigonal-dipyramidal.”  Pictured under short wave ultraviolet, white light, and long wave ultraviolet.