Extrusive igneous rock
Extrusive igneous rock is created when the magma comes out and cools outside on the Earth’s surface. It cools quickly when it gets on the ground.
http://media.tiscali.co.uk/images/feeds/hutchinson/ency/442002.jpg
http://media.tiscali.co.uk/images/feeds/hutchinson/ency/442002.jpg
http://www.nature.nps.gov/geology/usgsnps/rxmin/rock.html