gneiss

= Gneiss= definition-a banded or foliated metamorphic rock, usually of the same composition as granite. color- gray or pink but with dark streaks or layers texture:medium- coarse grained.Its characterized by discontinuous,altering dark and light layers. It often contains mica.and banding caused by segregation of different types of rock typicallylight and dark.

when heated and when pressure gets to it ;it changes it.
 * it is foliated
 * they may have been granite.granite which is an igneous rock.
 * gneiss is a crystalline rock
 * due to a physical and chemical similarity between many gneisses and plutonic igneous rocks some of the rocks are used for building stone and other structural purposes.
 * gneiss is found in the minnesota river valley.
 * gneiss is 3.6 billion years old its a metamorphic rock