Type of igneous rock that contains abundant and approximately equal amounts of plagioclase and potash feldspar , as well as other minerals.
The type region is Monzoni, Italy, in the Italian Tirol; similar rocks have been described from Montana, Norway, Sakhalin Island, and other localities. Monzonite is not rare, but it generally occurs in rather small, heterogeneous masses mixed with diorites, pyroxenites, or gabbros.