Tourmaline and Purpurite Optical Properties

Tourmaline

Purpurite

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1 Optical Properties

1.1 Luster

Vitreous

Not Available

1.2 Pleochroism

typically moderate to strong

StrongArthur Thomas

1.3 Dispersion

0.02NA

0.007 1

1.4 Transparency

Transparent, Translucent, Transparent to opaque

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

1.5 Refractive Index

1.614-1.6661.85-1.92

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

Orthorhombic

1.8 Birefringence

0.014-0.0400.070

0 0.296

1.9 Clarity

Transparent

TranslucentWalter Schumann

Tourmaline and Purpurite Optic Character

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

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Tourmaline and Purpurite Transparency

Similar to their colors, Tourmaline and Purpurite 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, Tourmaline is Translucent, Transparent and Transparent to opaque while Tourmaline is Translucent, Transparent and Transparent to opaque in appearance.