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Dravite
Dravite

Alexandrite
Alexandrite



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Dravite
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Alexandrite

Dravite and Alexandrite Optical Properties

Optical Properties

Luster

Vitreous
Vitreous

Pleochroism

Very strong: pale yellow colorless
-

Dispersion

0.020.02
0.005 1
👆🏻

Transparency

Transparent
Transparent, Transparent to nearly opaque

Refractive Index

1.614-1.6661.739-1.770
1 3.25
👆🏻

Optic Character

-
Biaxial/+

Crystal System

Trigonal Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3m
Orthorhombic

Birefringence

0.014-0.0320.007-0.010
0 0.296
👆🏻

Clarity

Transparent
Transparent

Dravite and Alexandrite Optic Character

Dravite and Alexandrite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Dravite and Alexandrite 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 Dravite and Alexandrite 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. Alexandrite has Biaxial/+ character.

Dravite and Alexandrite Transparency

Similar to their colors, Dravite and Alexandrite 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, Dravite is Transparent while Dravite is Transparent in appearance.