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Alexandrite
Alexandrite

Cobaltite
Cobaltite



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Alexandrite
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Cobaltite

Alexandrite and Cobaltite Optical Properties

1 Optical Properties
1.1 Luster
Vitreous
Not Available
1.2 Pleochroism
Not Available
Very weak
1.3 Dispersion
NANA
Fluorite Optical Properties
0.007 1
1.4 Transparency
Transparent, Transparent to nearly opaque
Gems
1.5 Refractive Index
1.739-1.770Not Available
Agate Opal
1 3.25
1.6 Optic Character
Biaxial/+
Not Available
1.7 Crystal System
Orthorhombic
Orthorhombic Pyramidal H-M Symbol (mm2) Space Group: P ca21
1.8 Birefringence
0.007-0.010Not Available
Achroite
0 0.296
1.9 Clarity
Transparent
Gems

Alexandrite and Cobaltite Optic Character

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

Alexandrite and Cobaltite Transparency

Similar to their colors, Alexandrite and Cobaltite 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, Alexandrite is Transparent and Transparent to nearly opaque while Alexandrite is Transparent and Transparent to nearly opaque in appearance.