Updated About content Print Article Share Article
views updated

monzogabbro A coarse-grained igneous rock consisting of essential plagioclase feldspar (see ESSENTIAL MINERAL), orthoclase feldspar, and pyroxene, with or without biotite. Plagioclase of labradorite composition is the dominant feldspar, making up 60–90% of the total feldspar. The presence of orthoclase feldspar distinguishes this rock from a gabbro.