Obsidian
| Type | Igneous Rock |
| Texture | Glassy |
| Origin | Extrusive/Volcanic |
| Chemical Composition | Felsic |
| Color | Reddish Brown mottled with black |
| Mineral Composition | Glass |
| Miscellaneous | Conchoidal Fracture |
| Tectonic Environment | Convergent Boundary – Andean-type subduction zones, intracontinental hot spots and rifts |
| Type | Igneous Rock |
| Texture | Glassy |
| Origin | Extrusive/Volcanic |
| Chemical Composition | Felsic |
| Color | Black |
| Mineral Composition | Glass |
| Miscellaneous | Conchoidal Fracture |
| Tectonic Environment | Convergent Boundary – Andean-type subduction zones, intracontinental hot spots and rifts |