Proustite and Sillimanite Optical Properties

Proustite

Sillimanite

Add ⊕

1 Optical Properties

1.1 Luster

Adamantine

Vitreous, Subadamantine, Silky

1.2 Pleochroism

Moderate; cochineal-red to blood-red

Colourless to pale brown to yellow

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Rarely transparentMore from other references

Transparent, Translucent

1.5 Refractive Index

2.792-3.0871.653-1.685

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

Orthorhombic

1.8 Birefringence

0.295-0.2960.020-0.022

0 0.296

1.9 Clarity

OpaqueUlrich Henn and Claudio C. Milisenda

Transparent

Proustite and Sillimanite Optic Character

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

Compare Black Gemstones

Proustite Vs Schorlomite

Proustite Vs Sheen Obsidian

Proustite Vs Serendibite

Proustite and Sillimanite Transparency

Similar to their colors, Proustite 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, Proustite is Gemmological Tables (2004) Rarely transparentMore from other references and OpaqueUlrich Henn and Claudio C. Milisenda while Proustite is Gemmological Tables (2004) Rarely transparentMore from other references and OpaqueUlrich Henn and Claudio C. Milisenda in appearance.