Color: Colorless, pink, wine-yellow and brownish.
Moh’s Hardness: 7
Refractive Index: 1.63-1.636
Critical Angle: 37.84°
Specific Gravity: 3.0
Fracture: Uneven, conchoidal
Heat Sensitivity: Yes in my experience
Birefringence (double refraction): Weak (.006)
Crystal Structure: Orthorhombic
Treatments: Generally none, sometimes can be irradiated.
What I prefer to polishing with: 8,000 pre-polish 50,000 polish with Zinc laps (scored)
Jeff’s Comments: Cuts and polishes pretty easily, and can be a little tough to polish sometimes. It seems to grab diamonds and can scratch. Watch the heat when dopping…
Design Notes: About any designs will work well… I like deep designs because the color(s) are usually on the light side
Design Links: White Asterism – This is great for clear rough if you have a piece that will work…