So in honor of #TheClubsRockingNewYear challenge now is my time to shine - I did Geology as my degree and of course have ended up making games for the last 20 years instead of being a world renowned Geologist... anyway and here is a very short thread on the types of rocks. Ignious Rocks - formed from the cooling of magma (the hot sticky stuff the explodes out of volcanoes - although technically it's called lava when that happens) either on the surface or under the earth's surface. An example of an ignious rock is granite - used in kitchen worktops.