* Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, and/or chemically active fluids.
* Minerals are the building blocks of rocks. During metamorphism, existing minerals can:
* Recrystallize: Minerals change their size, shape, or even chemical composition. This is driven by the intense conditions of metamorphism.
* Transform into different minerals: The original minerals may react with each other or with fluids, resulting in the formation of new minerals.
* Change their orientation: Minerals may align themselves in response to pressure, giving the metamorphic rock a distinctive texture (like foliation).
In summary: Minerals don't "behave" in a specific way during metamorphism, but rather respond to the changing conditions by recrystallizing, transforming, or reorienting themselves. This ultimately contributes to the formation of a new metamorphic rock with different properties than the original rock.
