From Wikipedia, the free encyclopedia.
Metamorphic rock are the result of the transformation of a pre-existing rock type, the protolith, in a process is called metamorphism. The nature of the protolith can be either sedimentary, igneous or older metamorphic rocks.
Metamorphic rocks can be classified according texture or mineral assembly (metamorphic facies).
See also: List of minerals, rock (geology), List of rocks
