Ettringite and Foitite Optical Properties

Ettringite

Foitite

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1 Optical Properties

1.1 Luster

Vitreous

1.2 Pleochroism

Not Available

Strong: pale lavender dark blueAnthony et al

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

TranslucentAnthony et al, Translucent

1.5 Refractive Index

1.470-1.491Not Available

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

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

1.8 Birefringence

0.021Not Available

0 0.296

1.9 Clarity

Transparent

TranslucentAnthony et al

Ettringite and Foitite Optic Character

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

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