Benitoite on natrolite
(barium titanium silicate)
|Crystal habit||Tabular dipyramidal crystals, granular|
|Mohs scale hardness||6 - 6.5|
|Diaphaneity||Transparent to translucent|
|Refractive index||1.757-1.759; 1.802-1.804|
|Pleochroism||Dichroic (blue to white)|
Insoluble: HCl, H2SO4|
Benitoite is a rare blue silicate mineral, found in hydrothermally altered serpentinite. Benitoite fluoresces under short wave ultraviolet light, appearing light blue in color. Dr. Louderback, who conducted the discovery examination of this mineral, named it Benitoite, “as it occurs near the head waters of the San Benito River in San Benito County,” California.
Uses of benitoiteEditar
Benitoite's rarity makes it a minor ore for barium or titanium at best. Rather, benitoite's main uses are as collector's specimens, especially in specimens which show off this mineral's unique crystals, or specimens in which benitoite occurs with its commonly associated minerals. Benitoite's hardness also makes it suitable for use as a gemstone, though the general lack of usable material has limited this use.
Associated minerals and locationsEditar
Benitoite typically occurs with an unusual set of minerals, along with minerals that make up its host rock. Frequently associated minerals include:
Benitoite is a rare mineral, found in very few locations, most prominently in southern San Benito County, California, but also in Japan and Arkansas. In the San Benito occurrence it is found in natrolite veins within glaucophane schist within a serpentinite body. In Japan it occurs in a magnesio-riebeckite-quartz-phlogopite-albite dike cutting a serpentinite body. Benitoite is typically found with some combination of natrolite, joaquinite, and neptunite on a greenish-grey serpentinite base. Finally, benitoite's fluorescence is used for identification purposes.
Benitoite is the official gem of E Clampus Vitus.
- ↑ http://webmineral.com/data/Benitoite.shtml WebMineral Listing
- ↑ http://www.mindat.org/min-624.html MinDat Listing
- ↑ http://mineral.galleries.com/minerals/silicate/benitoit/benitoit.htm Mineral Galleries
- ↑ Louderback, George Davis. Bentiote, A New California Gen Mineral. Bulletin of The Department of Geology, Vol. 5, No. 9. University of California Publications. July, 1907
- ↑ http://www.mineralsocal.org/scfm/newsletters/2002%20march.htm Friends of Mineralogy review of benitoite
- ↑ http://rruff.geo.arizona.edu/doclib/hom/benitoite.pdf Handbook of Mineralogy
- ↑ http://www.consrv.ca.gov/cgs/geologic_resources/mineral_resource_mapping/ Mineral Resources California Geologic Survey. Accessed December 31, 2005