Template:Danburite
From The Gemology Project
Danburite | |
---|---|
Chemical composition | CaB2(SiO4)2
Calcium boro-silicate |
Crystal system | Orthorhombic |
Habit | Prismatic |
Cleavage | Indistinct, basal |
Fracture | Sub-conchoidal |
Hardness | 7.0-7.5 |
Optic nature | Biaxial +/- |
Refractive index | 1.630-1.636 |
Birefringence | 0.006 |
Dispersion | low, 0.017 |
Specific gravity | 3.00 |
Lustre | Vitreous |
Pleochroism | Weak/not determinable |
Fluorescence | Light blue (LW) |