Thulite and Bertrandite Optical Properties

Thulite

Bertrandite

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1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

Present

none.

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Opaque, Translucent, Opaque . May be translucent in thin backlit sections.

TransparentAnthony et al, Handbook of mineralogy (2001)

1.5 Refractive Index

1.6951.583-1.614

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Orthorhombic Pyramidal H-M Symbol (mm2) Space Group: Ccm21

1.8 Birefringence

0.006-0.018Not Available

0 0.296

1.9 Clarity

OpaqueHerve Nicolas Lazzarelli

TransparentAnthony et al

Thulite and Bertrandite Optic Character

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

Similar to their colors, Thulite and Bertrandite 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, Thulite is Opaque, Opaque . May be translucent in thin backlit sections. and Translucent while Thulite is Opaque, Opaque . May be translucent in thin backlit sections. and Translucent in appearance.