- Igneous
These rocks are formed when magma or lava comes and cools on earths surface. If the lava erupts or wind blows at it it will probably have holes. A example would be pumice. Pumice has holes and can float on water because it ways less than the ?water pushing? Other Igneous rocks are smooth and are formed when the lava cools.Some of it like I think pahio-hio (pa- hio-io) looks like straw and is rock.
