Ettringite and Bertrandite Optical Properties

Ettringite

Bertrandite

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1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

Not Available

none.

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

TransparentAnthony et al, Handbook of mineralogy (2001)

1.5 Refractive Index

1.470-1.4911.583-1.614

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

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

1.8 Birefringence

0.021Not Available

0 0.296

1.9 Clarity

Transparent

TransparentAnthony et al

Ettringite and Bertrandite Optic Character

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

Similar to their colors, Ettringite 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, Ettringite is Translucent and Transparent while Ettringite is Translucent and Transparent in appearance.