augengneiss

noun1

1. •
   A type of metamorphic rock characterized by large, lenticular mineral grains or crystal aggregates (usually feldspar or quartz grains that have been deformed during metamorphism), resembling eyes, embedded within a finer-grained matrix.

   • Rocks of this migmatitic formation, having a smaller quantity of neosome, are augengneisses. — 1964