Metamorphic rocks are rocks that have become changed by intense heat or pressure while forming. One way to tell if a rock sample is metamorphic is to see if the crystals within it are arranged in bands. Examples of metamorphic rocks are marble, schist, gneiss, and slate.

Metamorphic rocks form when heat and pressure transform an existing rock into a new rock. Contact metamorphism occurs when hot magma transforms rock that it contacts. Regional metamorphism transforms large areas of existing rocks under the tremendous heat and pressure created by tectonic forces.

The original rock that has undergone metamorphism is called the protolith. Metamorphism therefore occurs at temperatures and pressures higher than 200oC and 300 MPa. Rocks can be subjected to these higher temperatures and pressures as they become buried deeper in the Earth.

about 200 to 320oC

Metamorphism. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition.

Metamorphic rocks have been modified by heat, pressure, and chemical processes, usually while buried deep below Earth’s surface. Exposure to these extreme conditions has altered the mineralogy, texture, and chemical composition of the rocks. Non-foliated metamorphic rocks do not have a layered or banded appearance.

There are two main types of metamorphic rocks: those that are foliated because they have formed in an environment with either directed pressure or shear stress, and those that are not foliated because they have formed in an environment without directed pressure or relatively near the surface with very little pressure …

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.

Granite is an igneous rock, thus option B is correct.

Answer

• Anthracite is the best example for metamorphic rock.
• Examples:
• Anthracite- looks shiny and has high percentage of carbon.
• Marble- It is formed from limestone.
• Quartzite- formed from the sand stone. Lime and sand stones are sedimentary rocks.

Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure). Schist and slate are sometimes used as building and landscape materials.

Uses of Metamorphic Rocks Quartzite and marble are commonly used for building materials and artwork. Marble is beautiful for statues and decorative items such as vases (see an example in Figure below). Ground up marble is also a component of toothpaste, plastics, and paper.