Template:Alexandrite
From The Gemology Project
| Alexandrite | |
|---|---|
| Chemical composition | Al2(BeO4)Beryllium aluminum oxide |
| Crystal system | Orthorhombic |
| Habit | Tabular, pseudo-hexagonal |
| Cleavage | Imperfect prismatic |
| Fracture | Weak, conchoidal |
| Hardness | 8.5 |
| Optic nature | Biaxial + |
| Refractive index | 1.744 - 1.755 |
| Birefringence | 0.009 |
| Dispersion | Low, 0.014 |
| Specific gravity | 3.70 - 3.72 |
| Lustre | Bright vitreous |
| Pleochroism | Strong |
