Sillimanite and Staurolite Optical Properties

Sillimanite

Staurolite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous, Subadamantine, Silky

Resinous

1.2 Pleochroism

Colourless to pale brown to yellow

X = colorless; Y = pale yellow; Z = golden yellow

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

Blue Chart Gem Identification (2010) More from other references

1.5 Refractive Index

1.653-1.6851.736-1.762

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

monoclinic

1.8 Birefringence

0.020-0.0220.009-0.015

0 0.296

1.9 Clarity

Transparent

Blue Chart Gem Identification (2010) More from other references

Sillimanite and Staurolite Optic Character

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

Sillimanite Vs Tanzanite

Sillimanite Vs Starlite

Sillimanite and Staurolite Transparency

Similar to their colors, Sillimanite and Staurolite 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.