changed from an original parent

is the parent rock that is metamorphosed: undergoes changes in mineral composition and texture, due to 4 changes:

1)temperature

2)pressure

3)reaction with heated water

4)tectonic stress

1)Recrystallization: minerals change size and shape without changing the identity of the mineral.

2)Phase Change: transformation of one mineral to another mineral with the same composition, but different crystal structure.

3)metamorphic reaction: growth of new mineral crystals that differ from those of the protolith.

4)Pressure solution: in water, mineral grains partially dissolve because pressure is exerted unevenly on crystall surface.

5)Plastic deformation: rock is squeezed or sheered at high temperature.