Description
The igneous rock diorite is a moderately mafic deep- and gangue rock with between 52 and 63% silica. Diorite is the more mafic equivalent of granodiorite and the deep- and gangue equivalent of the effusive rock andesite. Minerals with a reasonable crystal size that occur in diorite include pyroxene, amphibole, plagioclase, muscovite, and biotite. Diorite is a deep- or gangue rock exposed by tectonic uplift during orogeny. It forms in the core and magma channels of moderately mafic volcanoes.
Diorite
