FC: rocks by: hunter m.
1: metamorphic rocks are used in marble statues, graphite pencils, and slate roofs. metamorphic rock is made by heat and pressure.
2: the obsidian surgical blade and basalt road construction are both igneous rocks. igneous is just cooled lava.
3: coal trains, limestone chalk, and sandstone headstones are sedimentary rock.it's made by 2 rocks smooched together.