Benitoite MMT 323 from San Benito,
California; The Dallas Gem Mine.
CHEMISTRY - BaTiSi3O9
CRYSTALLOGRAPHY - Hexagonal
CRYSTAL GROWTH AND HABITS - Flat, tabular to pyramidal crystals with a triangular outline.
COLOR AND OPTICAL PROPERTIES - Sapphire blue to white or colorless, sometines pink. It can also be bicolored. Transparent to translucent. Under short wave Ultra Violet it fluoresces blue.
HARDNESS - 6 - 6.5
SPECIFIC GRAVITY - 3.65
LUSTER - Vitreous to sub vitreous
STREAK -
BREAKABILITY - Poor cleavage on {1011} and it has conchoidal fracture.
OCCURRENCE - At the San Benito County, California loacation it is found in natrolite veins that cut through a glaucophane schist which in a serpentine country rock.
ASSOCIATED MINERALS - Natrolite, Neptunite, Joaquinite (at San Benito County, CA)
MINERAL NAME - Named after its occurrence in San Benito County, California, USA