Color: Colorless, champagne to yellow

Moh’s Hardness: 6-6.5

Refractive Index: 1.52-1.568

Critical Angle: 41.14°

Specific Gravity: 2.56-2.62

Cleavage: Perfect in 3 directions, can be a problem when cutting

Fracture: Uneven, somewhat brittle

Dispersion: Low

Heat Sensitivity: Moderate in my experience

Dichroism: Weak

Birefringence (double refraction): Weak to medium (.005-.01)

Crystal Structure: Monoclinic

Treatments: Generally none