* Metamorphism is the process where existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, and/or chemically active fluids.
* Igneous rocks form from the cooling and solidification of magma or lava.
* Sedimentary rocks form from the accumulation and cementation of sediments.
So, while the source material for metamorphic rocks can be either igneous or sedimentary, the process of metamorphism itself is what transforms the original rock.
Here are some examples:
* Marble forms when limestone (a sedimentary rock) is metamorphosed.
* Slate forms when shale (a sedimentary rock) is metamorphosed.
* Gneiss can form from either igneous or sedimentary rocks.
It's important to remember that the original rock type influences the resulting metamorphic rock. For example, a metamorphic rock derived from an igneous rock will often retain some of the mineral characteristics of its original igneous source.
