![Top curves](../../../../jsp/jahia/templates/GSL/gsl_templates/img/keystage3/main_top_grad.gif)
Metamorphic Rocks
Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat and/or pressure within the Earth’s crust. They are crystalline and often have a “squashed” (foliated or banded) texture.
Slate
![Slate](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/slate.jpg)
Slate is made of fine-grained interlocking crystals which lie flat in the same direction, known as the cleavage direction, along which the rock easily splits.
Schist
![Schist](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/Schist.jpg)
Schist is made of medium-grained interlocking crystals. Its shiny appearance is due to the mineral mica. Crystals line up to give the rock wrinkly layers – this is called foliation.
Gneiss
![Gneiss](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/gneiss.jpg)
Gneiss is made of coarse-grained interlocking crystals. Crystals line up in pale and dark layers to give the rock a banded texture.
Marble
![Marble](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/marble.jpg)
![Bottom curves](../../../../jsp/jahia/templates/GSL/gsl_templates/img/keystage3/bottom_curve.gif)