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Sillimanite and Dioptase Optical Properties


Dioptase and Sillimanite Optical Properties


Optical Properties

Luster
Vitreous, Subadamantine, Silky   
Vitreous   

Pleochroism
Colourless to pale brown to yellow   
Weak; dark emerald green   

Dispersion
Not Available   
0.04   
13

Transparency
Transparent, Translucent   
TranslucentHerve Nicolas Lazzarelli   

Refractive Index
1.653-1.685   
1.644-1.720   

Optic Character
Not Available   
Not Available   

Crystal System
Orthorhombic   
Trigonal   

Birefringence
0.020-0.022   
0.051-0.053   

Clarity
Transparent   
TranslucentHerve Nicolas Lazzarelli   

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Sillimanite and Dioptase Optic Character

Sillimanite and Dioptase optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Sillimanite and Dioptase Physical Properties like crystallographic symmetry, pleochroism,etc. in the crystal. Some of the optical properties are refractive index, luster, optic character, pleochroism etc. Prominent among these is Sillimanite and Dioptase optic character. You might have noticed your gemologist rotating the gemstone while testing it. Rotating a gemstone along its optic axis helps in determining its optic character.

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Sillimanite and Dioptase Transparency

Similar to their colors, Sillimanite and Dioptase transparency can also be used as criteria for their primary identification. Although transparency cannot be the only criteria for gemstone identification, it can efficiently used in gemstone grading. Talking about their transparency, Sillimanite is Translucent and Transparent while Sillimanite is Translucent and Transparent in appearance.

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