| Gemstone Chart |
 Natural Sillimanite
Sillimanite is an alumino-silicate mineral with the chemical formula Al2SiO5. Sillimanite is a very rare trimorph and it has a common variety called fibrolite.
Color: violet blue, grey green, colorless, brown, green,
Categories: semi-precious stone
Chemical Composition: Al2OSiO4
Crystal Group: Orthorhombic
Refractive Index: 1.658 - 1.678
Hardness: 6 - 7.5
Density: 3.25
Occurrence: France, Madagascar, U.S.A., Sri Lanka, Burma. Kenya
|  Natural Star Sapphire
A star sapphire is a lovely gem that exhibits a six pointed star because of the intersection of six thin intersecting inclusions. When the gem is lit from above, the inclusions become quite visible and the star shape appears.A powdery grey-blue star sapphire is the centerpiece of a ring from the Art Deco period.
Color: Blue, green blue, violet, blue, black, brown, pink.
Categories: semi-precious stone
Chemical Composition: AL2O3
Crystal Group: Hexagonal
Refractive Index: 1.759-1.778
Hardness: 9
Density: 4
Occurrence: Sri Lanka, Burma, India, East Africa, Ankarana-Madagascar, Thailand.
|  Natural Taaffeite
The chemical formula of mineral Taaffeite is indicated by BeMgAl4O8 or Beryllium Magnesium Aluminum Oxide. Taaffeite actually belongs to the Oxides and Hydroxides mineral class. Taaffeite is one of the beautiful and Rarest gems in the world.
Color: Mauve, reddish violet, brownish-purple, pink, red, blue.
Categories: semi-precious stone
Chemical Composition: Beryllium magnesium aluminate wi
Crystal Group: Hexagonal
Refractive Index: 1.71-1.72.
Hardness: 8 - 8.5
Density: 3.60 - 3.71
Occurrence: Tunduru, Tanzania; Sri Lanka
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