Zoisite and Covellite Optical Properties

Zoisite

Covellite

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1 Optical Properties

1.1 Luster

Vitreous

Resinous

1.2 Pleochroism

X = pale pink to red-violet; Y = nearly colorless to bright pink or deep blue; Z = pale yellow to yellow-green

Marked

1.3 Dispersion

0.02NA

0.007 1

1.4 Transparency

Transparent, Translucent, Opaque . May be translucent in thin backlit sections.

OpaqueAnthony et al, Handbook of mineralogy (2001) More from other references

1.5 Refractive Index

1.685-1.7071.45-2.62

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Hexagonal

1.8 Birefringence

0.006-0.018Not Available

0 0.296

1.9 Clarity

Transparent

OpaqueAnthony et al

Zoisite and Covellite Optic Character

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

Similar to their colors, Zoisite and Covellite 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, Zoisite is Opaque . May be translucent in thin backlit sections., Translucent and Transparent while Zoisite is Opaque . May be translucent in thin backlit sections., Translucent and Transparent in appearance.