Bloodstone
From The Gemology Project
| Agate | |
|---|---|
| Chemical composition | Silicon dioxide SiO2 |
| Crystal system | Trigonal |
| Habit | Aggregate |
| Fracture | Conchoidal |
| Hardness | 6.5-7 |
| Refractive index | 1.535 - 1.539 |
| Specific gravity | 2.60 |
| Lustre | Vitreous |