Sapphire and Alexandrite Optical Properties

Sapphire

Alexandrite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous, Adamantine, Vitreous, Adamantine

Vitreous

1.2 Pleochroism

Strong

Not Available

1.3 Dispersion

0.02NA

0.007 1

1.4 Transparency

Transparent, Translucent, Transparent to opaque

Transparent, Transparent to nearly opaque

1.5 Refractive Index

1.762-1.7881.739-1.770

1 3.25

1.6 Optic Character

Not Available

Biaxial/+

1.7 Crystal System

Trigonal

Orthorhombic

1.8 Birefringence

0.008-0.0090.007-0.010

0 0.296

1.9 Clarity

Transparent

Sapphire and Alexandrite Optic Character

Sapphire and Alexandrite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Sapphire and Alexandrite 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 Sapphire and Alexandrite 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. Alexandrite has Biaxial/+ character.

Compare Birthstones » More

Sapphire Vs Emerald

Sapphire Vs Ruby

Sapphire Vs Opal

» More

More Compare Birthstones

Sapphire and Alexandrite Transparency

Similar to their colors, Sapphire and Alexandrite 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, Sapphire is Translucent, Transparent and Transparent to opaque while Sapphire is Translucent, Transparent and Transparent to opaque in appearance.