Foitite and Opal Optical Properties

Foitite

Opal

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1 Optical Properties

1.1 Luster

Vitreous

Vitreous, Pearly

1.2 Pleochroism

Strong: pale lavender dark blueAnthony et al

None

1.3 Dispersion

NANone

0.007 1

1.4 Transparency

TranslucentAnthony et al, Translucent

Transparent, Translucent, Transparent to translucent

1.5 Refractive Index

Not Available1.37-1.52

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

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

Trigonal

1.8 Birefringence

Not AvailableNot Available

0 0.296

1.9 Clarity

TranslucentAnthony et al

Transparent

Foitite and Opal Optic Character

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

Similar to their colors, Foitite and Opal 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, Foitite is Translucent and TranslucentAnthony et al while Foitite is Translucent and TranslucentAnthony et al in appearance.