Calcite
From The Gemology Project
| Calcite | |
|---|---|
| Chemical composition | CaCO3 |
| Crystal system | Hexagonal(Trigonal) |
| Habit | Massive |
| Hardness | 3 |
| Specific gravity | 2.69 - 2.71 |
| Optic nature | Uniaxial - |
| Refractive Index | 1.486 - 1.658 |
| Birefringence | 0.172 - 0.19 |
| Lustre | Vitreous |
