16.14.03: Bi-color
- Page ID
- 4344
Bi-color Tourmaline | |
---|---|
Chemical composition | Complex borosilicate |
Crystal system | Trigonal |
Habit | Prismatic |
Cleavage | None |
Fracture | Conchoidal |
Hardness | 7- 7.5 |
Optic nature | Uniaxial - |
Refractive index | 1.62 - 1.64 |
Birefringence | 0.014 - 0.040 |
Dispersion | Low, 0.017 |
Specific gravity | 3.01 - 3.11 |
Lustre | Vitreous |
Pleochroism | Strong |
Figure \(\PageIndex{1}\): Bi-color tourmaline
Photo courtesy of Lembeck Gems