noun. A gray, fine-grained volcanic rock consisting chiefly of plagioclase feldspar and one or more mafic minerals.

noun. A volcanic rock of wide-spread occurrence, especially in the Cordilleran region of North America.

noun. An eruptive rock allied to trachyte, consisting essentially of a triclinic feldspar, with pyroxene, hornblende, or hypersthene.

noun. A class of fine-grained intermediate igneous rock, of volcanic origin, containing mostly plagioclase feldspar.

noun. a dark grey volcanic rock

"A third type of magma, called andesite, named after the Andes Mountains where it is often found, is composed of a mixture of both felsic and mafic magma."

trachytic andesite  

igneous rock  

breccia  conical-shaped  cornelian  diorite  double-peaked