The metamorphic rocks are derived from pre-existing sedimentary and magmatic rocks by mineralogical, chemical, and structural changes, essentially in the solid state, in response to marked changes in temperature and/or pressure (both hydrostatic and oriented), during deeper burial into deeper parts of the Earth´s crust. During these processes parallel orientation of newly formed minerals generally forms (schistosity). Hydrothermal metamorphism represents a special type, because it is related to the migration of solutions near ore veins. Contact metamorphism results from temperature effect near contact with magmatite bodies.
In the Virtual Museum there are total 533 samples