Extrusive rocks are Basalt, Rhyolite, Andesite, and Obsidian. Intrusive rocks are diorite, gabbro, granite, pegmatite, and peridotite.
A metamorphic rock is a result of a transformation of a pre-existing rock. The original rock is subjected to very high heat and pressure, which cause obvious physical and/or chemical changes.
There are two basic types of metamorphic rocks. Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.
The other type of metapmorphic rock is Non-foliated metamorphic rocks such as hornfels, marble, quartzite, and novaculite do not have a layered or banded appearance.