Tantalite and Sillimanite Optical Properties

Tantalite

Sillimanite

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1 Optical Properties

1.1 Luster

Resinous

Vitreous, Subadamantine, Silky

1.2 Pleochroism

Not Available

Colourless to pale brown to yellow

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

TransparentWalter Schumann, Gemstones of the world (2001) More from other references

Transparent, Translucent

1.5 Refractive Index

2.190-2.4571.653-1.685

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

1.8 Birefringence

0.0830.020-0.022

0 0.296

1.9 Clarity

TransparentWalter Schumann

Transparent

Tantalite and Sillimanite Optic Character

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

Similar to their colors, Tantalite and Sillimanite 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, Tantalite is Gemstones of the world (2001) More from other references and TransparentWalter Schumann while Tantalite is Gemstones of the world (2001) More from other references and TransparentWalter Schumann in appearance.