| Name | Black Obsidian |
| Class | Volcanic rocks |
| Category | Natural volcanic glass |
| Crystal system | Amorphous |
| Chemical composition | Silicon dioxide (SiO₂) with traces of magnesium and iron |
| Hardness (Mohs scale) | 5 to 6 |
| Transparency | Opaque |
| Geographical origin | Mexico, Iceland, Japan, Italy, United States (notably Yellowstone) |






















































































































































































































