Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!

Geography

Classification of rocks

There are three types of rock: igneous, sedimentary and metamorphic. Watch this video to find out more.

Video

In order to see this content you need to have both Javascript enabled and Flash installed. Visit BBC Webwise for full instructions

Key points

  • Igneous rocks like basalt and granite are formed when molten magma from the Earth's interior cools.
  • It either cools on the Earth's surface after a volcanic eruption or inside the Earth to form intrusive rock.
  • Metamorphic rocks have been subjected to massive heat or pressure and are usually very hard wearing. Examples are marble and slate.
  • Sedimentary rocks are formed from sediments at the bottom of a lake or sea, which compress over millions of years. Examples are sandstone, limestone and clay.

All Geography videos

Rock landscapes and processes index

BBC navigation

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.