| Table 4 Representative types of rocks of different origins. | ||
| Igneous | Sedimentary | Metamorphic |
| Basalt | Chalk | Gneiss (from granite) |
| Granite | Conglomerate | Marble (from limestone or chalk) |
| Obsidian | Limestone | Quartzite (from sandstone) |
| Pumice | Sandstone | Schist (from micaceous shales) |
| Rhyolite | Shale | Slate (from shale) |