Template:Danburite
From The Gemology Project
Danburite | |
---|---|
Chemical composition | CaB2(SiO4)2
Calcium Boro-Silicate |
Crystal system | orthorhombic |
Habit | prismatic
with a rhombic cross section, a wedge-shape termination of dome |
Cleavage | indistinct |
Fracture | sub-conchoidal |
Hardness | 7.0-7.5 |
Optic nature | biaxial +,- |
Refaction index | 1.630-1633 to 1636-1641 |
Birefringence | 0.006 |
Dispersion | low, 0.017 |
Specific gravity | 3.00 |
Lustre | vitreous |
Pleochroism | weak / not determinable
Fluorescece : light blue (LW) |