Color:
Colorless, blue and very rarely pink

Clarity: Type II
Optic Character: DR Uniaxial Positive
Cause of Color: Charge transfer involving Fe and Ti
Fluorescence: Inert LW; Strong chalky blue SW
Fracture : Concoidal to uneven
Luster : Vitreous
Cleavage : One direction; indistinct
Durability: Fair

Characteristics for Identification:
High dispersion, color zoning, strong pleochroism, high birefringence

Localities:
San Benito County, California, USA
(only known source)

Beniotite is a very rare mineral that was discovered in 1907 in San Benito County in California. It has never been found elsewhere. It was originally mistaken for sapphire. Benitoite is very highly dispersive (the ability to take white light and disperse it into various components of the spectrum). Benitoite is associated with other rare minerals such as black-red neptunite, snow white natrolite and brown-yellow joaquinite. Since the only source of this rare combination occurres at San Benito, California, it has been designated the California state gemstone. Crystals, and cut stones, tend to be small and quite expensive!

Associated Minerals: Neptunite Natrolite Joaquinite

This gemstone is often confused with: Azurite Iolite Spinel Tourmaline Sapphire Scapolite Cortanite, Tanvolite, Tanzalike & other Lab Grown imitations Glass Plastic

The Curious Lore of Precious Stones:
by George Frederick Kunz

Gemstone Buying Guide: A Guide to Buying
by Renee Newman