4. Metamorphic Rocks

Metamorphic Rocks - formed by the influence of heat and pressure on other rocks resulting in changes in mineralogy and texture.

  • Gneiss: has a banded appearance with alternating composition; may be formed by metamorphism of an igneous or sedimentary rock
  • Slate: fine-grained and platy; fissile; formed by the metamorphism of shale.
  • Schist: rock flaky minerals (eg mica) aligned in a parallel fashion; formed by the metamorphism of shale and slate.
  • Quartzite: hard, mainly composed of quartz; formed by the metamorphism of sandstone.
  • Marble: a coarse, but even-grained rock formed by the metamorphism of limestone.
Watch the video below to see how metamorphic rocks are formed. You will learn the role of heat and pressure in forming metamorphic rocks.