Dravite and Onyx Optical Properties

Dravite

Onyx

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1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

Very strong: pale yellow colorless

Not Available

1.3 Dispersion

0.02NA

0.007 1

1.4 Transparency

Transparent

Translucent, Opaque, Translucent to opaque

1.5 Refractive Index

1.614-1.6661.530-1.543

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

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

Trigonal

1.8 Birefringence

0.014-0.032Not Available

0 0.296

1.9 Clarity

Transparent

OpaqueHerve Nicolas Lazzarelli

Dravite and Onyx Optic Character

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

Similar to their colors, Dravite and Onyx 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.