Sillimanite and Manganotantalite Optical Properties

Sillimanite

Manganotantalite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous, Subadamantine, Silky

Not Available

1.2 Pleochroism

Colourless to pale brown to yellow

Sometimes strongArthur Thomas

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

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

1.5 Refractive Index

1.653-1.6852.19-2.34

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Not Available

1.8 Birefringence

0.020-0.0220.015

0 0.296

1.9 Clarity

Transparent

TransparentWalter Schumann

Sillimanite and Manganotantalite Optic Character

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

Compare Blue Gemstones

Sillimanite Vs Starlite

Sillimanite Vs Tanzanite

Sillimanite Vs Strontium Titanate

Sillimanite and Manganotantalite Transparency

Similar to their colors, Sillimanite and Manganotantalite 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, Sillimanite is Translucent and Transparent while Sillimanite is Translucent and Transparent in appearance.