1. Sedimentary-formed from particles of sand, shells, pebbles, and other fragments. Generally soft and breaks apart easily.
2. Metamorphic-formed under the surface of earth from the change from the heat and pressure. These rocks will have a shinny crystal like shine to them.
3. Igneous-formed when the magma cools down and hardens. Won't have a shinny look to it. Sometimes will have tiny holes in them.