* Extrusive Rocks: These form when magma erupts onto the Earth's surface as lava and cools relatively quickly. The rapid cooling leaves little time for large crystals to form.
* Coarse-Grained Rocks: These have large, visible crystals, indicating a slow cooling process. This occurs when magma cools deep underground (intrusive setting).
Therefore, a coarse-grained texture is indicative of intrusive rocks, not extrusive rocks.
Here are some examples of extrusive and intrusive rocks:
* Extrusive: Basalt, rhyolite, obsidian, pumice
* Intrusive: Granite, gabbro, diorite
