Andalusite and Foitite Optical Properties

Andalusite

Foitite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous, Greasy

Vitreous

1.2 Pleochroism

strongly trichroic

Strong: pale lavender dark blueAnthony et al

1.3 Dispersion

0.02NA

0.007 1

1.4 Transparency

Transparent, Translucent

TranslucentAnthony et al, Translucent

1.5 Refractive Index

1.627-1.650Not Available

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

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

1.8 Birefringence

0.009-0.010Not Available

0 0.296

1.9 Clarity

Transparent

TranslucentAnthony et al

Andalusite and Foitite Optic Character

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

Compare Brown Gemstones

Andalusite Vs Baddeleyite

Andalusite Vs Augite

Andalusite Vs Baryte Barite

Andalusite and Foitite Transparency

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