gneiss vs. granite

gneiss

noun

  1. a metamorphic rock, generally made up of bands that differ in color and composition, some bands being rich in feldspar and quartz, others rich in hornblende or mica.

granite

noun

  1. a coarse-grained igneous rock composed chiefly of orthoclase and albite feldspars and of quartz, usually with lesser amounts of one or more other minerals, as mica, hornblende, or augite.
  2. anything compared to this rock in great hardness, firmness, or durability.