Template:Jeremejevite
From The Gemology Project
Jeremejevite | |
---|---|
Chemical composition | Al6B5O15(F,OH)3 |
Crystal system | Hexagonal or Orthorhombic* |
Habit | Prismatic |
Cleavage | None |
Fracture | Concoidal |
Hardness | 7 |
Optic nature | Uniaxial (-) or biaxial* |
Refractive index | nω=1.653 nε=1.640 |
Birefringence | δ = 0.013 |
Dispersion | 0.0130 |
Specific gravity | 3.27-3.31 (Webster,1994,p.898) |
Lustre | Vitreous |
Pleochroism | Faint to Strong |