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Sillimanite

  • Color: light yellowish green, light blue, greyish, brown, colorless
  • Hardness: 6.5 - 7.5
  • Refractive index: 1.65 - 1.68
  • Density: 3.25
  • Chemical composition: Al2OSiO5
  • Crystal structure: orthorhombic
  • Origins: USA, Madagascar, India, Sri Lanka, Burma, Australia, Czechoslovakia, Italy, Germany, Brazil.

Collectors stone rarely used in jewelry, also known as fibrolite. Stones are generally not treated.


 


Market values of Sillimanite  

Occurrence of Sillimanite  

Historical values  


 
 
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