andesitic tuff stone on white background. extrusive igneous rock.

alkali andesite andesites background basalt black bomb chiefly coarsegrained common composed composition consisting crystal diorite eruption extrusive feldspar finegrained geology gold granite group hard igneous intermediate intrusive isolated lava macro mass material mica microcline mineral molten mostly name natural nature occurs ore orthoclase phaneritic plagioclase quartz removes rhyolite rock rough sedimentary single stone tephra texture used viscous volcanic volcano