Tanzanite and Covellite Optical Properties

Tanzanite

Covellite

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1 Optical Properties

1.1 Luster

Vitreous

Resinous

1.2 Pleochroism

Present

Marked

1.3 Dispersion

0.03NA

0.007 1

1.4 Transparency

Transparent, Translucent, Transparent to translucent

OpaqueAnthony et al, Handbook of mineralogy (2001) More from other references

1.5 Refractive Index

1.685-1.7071.45-2.62

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Hexagonal

1.8 Birefringence

0.006-0.018Not Available

0 0.296

1.9 Clarity

TransparentUlrich Henn and Claudio C. Milisenda

OpaqueAnthony et al

Tanzanite and Covellite Optic Character

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

Similar to their colors, Tanzanite and Covellite 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, Tanzanite is Translucent, Transparent and Transparent to translucent while Tanzanite is Translucent, Transparent and Transparent to translucent in appearance.