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www.mineralgallery.co.za Minerals P-T |
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Name
Tanzanite
Chemistry
Ca2(Al,OH)Al2(SIO4)
Uses
As a gemstone or a mineral specimen
Color
Typically green to blue, the color improves to a sapphire blue when heated.
Hardness
6 - 6.5
Specific gravity
3.1 - 3.37
Crystals
Orthorhombic
Accompanied by:
Berryl and mica
Similar to:
Sapphire when cut
Tanzanite Ca2Al3Si3O12(OH) is a hydrated Calcium Aluminum silicate mineral.
It comes from Arusha in Tanzania which also gave it it's name Tanzanite.
Tanzanite is the blue or purple variety of the mineral Zoisite.
Tanzanite is a beautiful and popular gemstone when cut.
Tanzanite valuesdepends on the saturation of the color. The and deep violet blue and deep blue stones are the most treasured. The prices of Tanzanite is usually very high due to the demand and scarcity of the gem. It is usually a yellow brown when found and is almost always heat treated to improve it's color to a pleasant sapphire blue.
Tanzanite has good one directional cleavage and uneven to conchoidal fracture and mainly occurrs in hydrothermal veins, metamorphic rocks and pegmatite rocks.
