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name:
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Hauyn
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| gemstone variety:
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Hauyn
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| trade name 1:
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Hauyn
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| trade name 2:
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Hauynite
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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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very intensive blue
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Quality :
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the intensity of the cobalt-blue colour is decisive.
Some stones are 'milky' and therefore have less lustre and
brilliancy. Few inclusions are accepted, as completely
flawless stones do hardly occur.
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History :
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Hauyn was named in 1807 after the French mineralogist
R.J.Hauy. In gem quality and decent size it is one of the
very rarest gemstones to be found.
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Curiosities / Saga :
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Countrys of Origin :
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In the volcanic area of the Eifel region near the lake
of Laach in middle-west of Germany, 5-20 meters deep in
pumicestone.
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Birthstone :
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Hardness :
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5.5 - 6.0
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Treatment :
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none
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Size :
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mainly very small sizes below 0.25 carat. Cut stones
in fine quality of more than 0.50 carat are extremely
rare
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Specific gravity :
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2.40 - 2.50
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Chemical Composition Formula :
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(Na,Ca)8-4 (SO4)2-1 (AlSiO4)6
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Chemical Composition Name :
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sulphur- bearing- sodium- calcium- aluminium-
silicate
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Crystal system :
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cubic
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Light refraction :
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1.490 to 1.505
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Double refraction :
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single refractive
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