| Over millions of years, pressure can convert peat into ____. |
coal |
| A coarse-grained, plutonic igneous rock is ____. |
granite |
| A very light, porous, volcanic igneous rock is ____. |
marble |
| A black, glassy, volcanic igneous rock is ____. |
obsidian |
| A metamorphic rock derived from shale is ____. |
pumice |
| A metamorphic rock derived from limestone is ____. |
quartzite |
| Limestone, sandstone, and ____ are sedimentary rocks. |
shale |
| A metamorphic rock derived from sandstone is ____. |
slate |
