- Igneous rocks are formed from the cooling and solidification of molten rock material. They are classified based on their texture and composition. - Intrusive igneous rocks form when magma cools slowly within the Earth's crust. They are typically coarse-grained and have a crystalline texture. Examples include granite, diorite, and gabbro. - Extrusive igneous rocks form when magma cools quickly at the Earth's surface. They are typically fine-grained and have a glassy or porphyritic texture. Examples include basalt, andesite, and rhyolite. - Sedimentary rocks are formed from the accumulation and compaction of sediments. They are classified based on their texture and composition. - Clastic sedimentary rocks are formed from the accumulation of fragments of other rocks. They are classified based on the size of the fragments. Examples include conglomerate, sandstone, and shale. - Chemical sedimentary rocks are formed from the precipitation of minerals from solution. They are classified based on their composition. Examples include limestone, dolomite, and evaporites. - Metamorphic rocks are formed from the transformation of existing rocks by heat, pressure, and chemical reactions. They are classified based on their texture and composition. - Foliated metamorphic rocks have a layered or banded texture. They are formed from the metamorphism of sedimentary or igneous rocks. Examples include slate, schist, and gneiss. - Non-foliated metamorphic rocks do not have a layered or banded texture. They are formed from the metamorphism of igneous or sedimentary rocks that are composed of a single mineral. Examples include marble, quartzite, and amphibolite.