An igneous, crystalline in structure, consisting essentially of a triclinic feldspar and hornblende. It includes part of what was called greenstone.
Very hard green or gray volcanic rock
A coarse to medium grained igneous rock composed essentially of plagioclase feldspar with some ferromagnesium minerals such as hornblende, augite, and biotite. The coarser grained equivalent of andesite.
A plutonic (intrusive) igneous rock that is coarse-grained and composed mainly of plagioclase feldspar, pyroxene and some amphibole (especially hornblende) and biotite with small amounts of quartz and K-feldspar.