Scapolite

Color: Yellow, purple, pink, colorless, greenish

Moh’s Hardness: 5-6

Refractive Index: 1.54-1.56

Critical Angle: 40.49°

Specific Gravity: 2.57-2.74

Cleavage: Perfect in 2 directions

Fracture: Conchoidal, brittle

Dispersion: Medium (.017)

Heat Sensitivity: Moderate

Dichroic: Moderate

Birefringence (double refraction): Weak to medium (.009-.020)

Crystal Structure: Tetragonal

Treatments: Generally none, but Purple may be irradiated and/or heat treated