Metamorphic rocks are one of the three great divisions of all rock types, and so there is a great variety of metamorphic rock types. In general, if the protolith of a metamorphic rock can be …

Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found …

Dec 27, 2025 · metamorphic rock, any of a class of rocks that result from the alteration of preexisting rocks in response to changing environmental conditions, such as variations in …

Oct 27, 2021 · Metamorphic rocks form when high temperatures and pressure act on a rock to alter its physical and chemical properties (metamorphism means 'to change form'). These …

Oct 19, 2023 · Metamorphic rocks start as one type of rock and—with pressure, heat, and time—gradually change into a new type of rock.

Feb 24, 2024 · Learn about metamorphic rocks in geology. Discover how they form, the types, examples, and how to identify them.

Apr 30, 2025 · Metamorphic rocks are the third great class of rocks. They occur when sedimentary and igneous rocks become changed, or metamorphosed, by conditions …

Metamorphic rocks start off as igneous, sedimentary, or other metamorphic rocks. These rocks are changed when heat or pressure alters the existing rock’s physical or chemical make up.

Metamorphic rocks are created when heat, pressure, and/or fluids change preexisting rocks. The rock cycle shows that both igneous and sedimentary rocks can become metamorphic rocks. …

Metamorphic rocks form when existing rocks are transformed by heat, pressure, and fluid activity deep within Earth’s crust, creating new minerals, textures, and structures that reveal past …