Template:Idocrase
From The Gemology Project
| Idocrase | |
|---|---|
| Chemical composition | Complex calcium aluminum silicate |
| Crystal system | Tetragonal |
| Habit | Prismatic terminated by truncated pyramids, massive, fibrous |
| Cleavage | Poor |
| Fracture | Sub-conchoidal |
| Hardness | 6.5 |
| Optic nature | Uniaxial +/- |
| Refractive index | 1.700 - 1.725 |
| Birefringence | 0.005 |
| Dispersion | Low, 0.019 |
| Specific gravity | 3.25-3.50 |
| Lustre | Vitreous |
| Pleochroism | Weak to distinct (shades of body color) |
