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Mellite
Mellite

Dravite
Dravite



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Mellite
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Dravite

Mellite and Dravite Optical Properties

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Optical Properties

Luster

Vitreous
Vitreous

Pleochroism

Weak: yellowish brown yellowAnthony et al
Very strong: pale yellow colorless

Dispersion

0.010.02
0.005 1
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Transparency

-
Transparent

Refractive Index

1.509-1.5411.614-1.666
1 3.25
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Optic Character

-
-

Crystal System

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

Birefringence

0.0300.014-0.032
0 0.296
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Clarity

TransparentUlrich Henn and Claudio C. Milisenda
Transparent

Mellite and Dravite Optic Character

Mellite and Dravite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Mellite and Dravite 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 Mellite and Dravite 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.

Mellite and Dravite Transparency

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