GEMMOLOGICAL PROPERTIES

Rubellite

Family:

Tourmaline

Crystal System:

Trigonal

Specific Gravity:

3.03 - 3.25

Hardness:

7 - 7.5

Refractive Index:

1.61- 1.65

Chemical Composition:

Birefringence:

-0.018 to -0.040

Pleochroism:

Moderate to Strong

Lustre:

Vitreous - Resinous

Cleavage:

Indistinct

Fracture:

Uneven, Chonchoidal