Igneous (ĭg'nē-əs) rocks are one of three rock types in the rock cycle. Igneous rocks are devided into intrusive and extrusive types. Granite and basalt are both igneous rocks, intrusive and extrusive, or plutonic and volcanic respectively. Igneous rocks are formed from a completely molten state, as opposed to metamorphic rocks which keep some of the characteristics of their source material. Igneous rocks vary in composition from felsic to mafic.