Three Kinds of Rocks

Deep underground, it is SO hot that rocks melt into gooey liquid called 'magma.' When a volcano erupts, magma shoots out and is called 'lava.' When lava cools down, it turns hard and becomes an igneous rock! 'Igneous' means 'fire.' Granite is an igneous rock — it cooled slowly underground and has speckles. Obsidian is another — it cooled super fast and looks like shiny black glass!