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name:
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Tanzanite
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| gemstone variety:
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Zoisite
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| trade name 1:
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Tanzanite
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| trade name 2:
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Blue Zoisite
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| trade name 3:
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| basic colour:
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blue
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Colour :
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violet to a strong blue
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Quality :
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the more intense the blue colour, the more valuable
the stone. Facetted Tanzanite should have no visible
inclusions and balanced proportion is in the cutt
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History :
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Tanzanite is quite a 'new' gemstone found in the
1960s. In its natural stage it is a brownish-grey Zoisite
that turns to a fantastic blue-violet colour after modest
heating. It was named Tanzanite by Tiffany & Co. in the
late 1960s. Today it is a very popular gemstone, due to its
beautiful appearence. One of the best and nicest Tanzanites
is a flawless gem of 122.70 carats in the museum of the
Smithsonions Institute.
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Curiosities / Saga :
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Countrys of Origin :
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Tanzania, at the town Arch near the famous
Killimancharo mountain
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Birthstone :
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Hardness :
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6.5 - 7
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Treatment :
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heat-treated
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Size :
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normally 0.50 to 10.00 carat
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Specific gravity :
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3.35
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Chemical Composition Formula :
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Ca2Al3Si3O12 (OH)
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Chemical Composition Name :
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hydrous- calcium- aluminium- silicate
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Crystal system :
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rhombic
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Light refraction :
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1.690 - 1.700
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Double refraction :
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0.008 - 0.009
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