Norite is an igneous rock that is composed mainly of the minerals plagioclase, orthopyroxene, and usually a small amount of olivine. This rock type can be found in various geological settings, including inclusions in volcanic rocks, in layered intrusions, and in ophiolitic complexes. Synonyms for norite include gabbro, troctolite, anorthosite, and pyroxenite. Gabbro and norite are both coarse-grained igneous rocks that have a similar mineral composition. Troctolite is a rock that is almost entirely composed of plagioclase and olivine, and has a similar texture to norite. Anorthosite is an igneous rock that is composed mainly of plagioclase and is often associated with norite in layered intrusions.