The final Rock group is Metamorphic. A Metamorphic rock forms from Heat and pressure deep beneath the Earth's surface. Metamorphic rocks don't form, they change rocks into different types of rocks. When a rock has heat and pressure happening to it, it's appearance, texture, crystal structure, and mineral content change. Metamorphic rocks can form out of igneous, sedimentary, and other Metamorphic rocks. Metamorphic rocks that have their grains arranged parallel are called foliated. Ones with grains arranged randomly are called non-foliated.
Metamorphic rocks also have uses, some of those are roofing material, decorative stones, paving, building, and sculpture material.
Metamorphic rocks also have uses, some of those are roofing material, decorative stones, paving, building, and sculpture material.