Onyx and Iolite Optical Properties

Onyx

Iolite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

Not Available

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Translucent, Opaque, Translucent to opaque

Transparent, Translucent, Transparent to translucent

1.5 Refractive Index

1.530-1.5431.52-1.56

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

Orthorhombic

1.8 Birefringence

Not AvailableNot Available

0 0.296

1.9 Clarity

OpaqueHerve Nicolas Lazzarelli

Transparent to translucent

Onyx and Iolite Optic Character

Onyx and Iolite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Onyx and Iolite 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 Onyx and Iolite 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 Gems for Capricorn » More

Onyx Vs Crystal Quartz

Onyx Vs Hawks Eye

Onyx Vs Quartz Smoky

» More

More Compare Gems for Capricorn

Onyx and Iolite Transparency

Similar to their colors, Onyx and Iolite 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, Onyx is Opaque, Translucent and Translucent to opaque while Onyx is Opaque, Translucent and Translucent to opaque in appearance.