Luster
Pleochroism
Dispersion
Transparency
Refractive Index
Optic Character
Crystal System
Birefringence
Clarity
X = pale pink to red-violet; Y = nearly colorless to bright pink or deep blue; Z = pale yellow to yellow-green
Transparent, Translucent, Opaque . May be translucent in thin backlit sections.
Strong: X = pale emerald green or colourless; Y = dark emerald green or pale blue; Z = dark emerald green or pale blue