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Reference Values of Gems
Database updated: 15 Jan 2017
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Iolite

  • Color: blue, violet-blue
  • Hardness: 7 - 7.5
  • Refractive index: 1.52 - 1.56
  • Density: 2.53 - 2.78
  • Chemical composition: Mg2Al3(AlSi5O18)
  • Crystal structure: orthorhombic
  • Origins: Brazil, USA, Canada, Madagascar, Sri Lanka, India, Burma.

Iolite (dichroite, water sapphire) has a significant pleochroism effect (from violet-blue to colorless or yellowish). Stones are generally not treated.

 

Iolite 8.30 cts.
Iolite 8.30 cts.
Published under permission: Miguel Angel Lopez

 


Market values of Iolite  

Occurrence of Iolite  

Historical values  


 
 
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