Tourmaline and Foitite Optical Properties

Tourmaline

Foitite

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1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

typically moderate to strong

Strong: pale lavender dark blueAnthony et al

1.3 Dispersion

0.02NA

0.007 1

2.5 Transparency

Transparent, Translucent, Transparent to opaque

TranslucentAnthony et al, Translucent

2.7 Refractive Index

1.614-1.666Not Available

1 3.25

2.10 Optic Character

Not Available

2.11 Crystal System

Trigonal

Trigonal Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3m

2.12 Birefringence

0.014-0.040Not Available

0 0.296

3.4 Clarity

Transparent

TranslucentAnthony et al

Tourmaline and Foitite Optic Character

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

Similar to their colors, Tourmaline and Foitite 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.