Color: Pale yellow to brown

Moh’s Hardness: 6-6.5

Refractive Index: 1.52-1.568

Critical Angle: 41.14°

Specific Gravity: 2.56-2.70

Cleavage: Perfect

Fracture: Uneven, can be brittle

Dispersion: Low (.012)

Heat Sensitivity: Moderate in my experience

Dichroism: Weak

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

Crystal Structure: Triclinic

Treatments: Generally none