Metamorphic rocks are dependent on the degree of melting, where complete melting “resets” the rock to magma and will then form igneous rocks when cooled.

Characteristics of metamorphic rocks Heat and/or pressure will cause the elements in the original rock to react and re-form. Metamorphic rocks are highly resistant to erosion and are often used in building materials.

Explanation: Weathering is the process of breakdown of rocks through the action of wind, air, water and by the action of organisms. The metamorphic rocks get gradually converted into sedimentary rocks through this process. The big rocks change into small rock particles called sediments.

The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks. Metamorphic rocks are often squished, smeared out, and folded. Despite these uncomfortable conditions, metamorphic rocks do not get hot enough to melt, or they would become igneous rocks!

We often find metamorphic rocks in mountain ranges where high pressures squeezed the rocks together and they piled up to form ranges such as the Himalayas, Alps, and the Rocky Mountains. Metamorphic rocks are forming deep in the core of these mountain ranges.

Marble is a limestone or a dolostone that has been metamorphosed. It will have an acid reaction that is similar to the limestone or dolostone from which it was formed. Other Applications of the “Acid Test”: Geologists can use dilute hydrochloric acid to help identify the cementing agent of sandstones.

While metamorphic rocks range in hardness on the Mohs scale, they are almost always harder than their parent rock material.