Fayalite and Opal Optical Properties

Fayalite

Opal

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1 Optical Properties

1.1 Luster

Vitreous, Resinous

Vitreous, Pearly

1.2 Pleochroism

Faint

None

1.3 Dispersion

NANone

0.007 1

1.4 Transparency

TransparentAnthony et al, Handbook of mineralogy (2001)

Transparent, Translucent, Transparent to translucent

1.5 Refractive Index

1.827-1.8791.37-1.52

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Trigonal

1.8 Birefringence

0.042-0.051Not Available

0 0.296

1.9 Clarity

TransparentAnthony et al

Transparent

Fayalite and Opal Optic Character

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

Similar to their colors, Fayalite 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, Fayalite is Handbook of mineralogy (2001) and TransparentAnthony et al while Fayalite is Handbook of mineralogy (2001) and TransparentAnthony et al in appearance.