We learn more about the features of Earth - Part 18 Igneous Rocks- Information for kids

The earth's surface is covered with many types of rock which has different features and uses.  We will learn more about one of the types of rocks today.

The rock inside of the volcano is so hot that it melts and forms magma.  If this magma cools down, it forms igneous rock.  These rock can be formed inside or outside the volcano.

Magma can be forced into rocks, blown out in volcanic explosions or forced to the surface as lava. 

There are melted minerals in the magma and when it cools down it arranges itself in different forms.  The way it arranges itself will determine what type of igneous rock is formed.  There are more than 700 different types of igneous rock.

Examples of igneous rocks include basalt, granite, pumice, obsidian, tuff, diorite, gabbro and andesite. 

If the basalt is exposed to a lot of pressure and heat over a long time, it will form granulite which is a metamorphic rock - in other words a rock that changed into another type of rock.

When the molten rock is blown out of the volcano very fast and forms air bubbles that cools down very fast, a pumice stone will form.  This is a lightweight stone and can be use as an abrasive like when you want to scrub the dead cells from your feet.  You can read here for extra information on the uses of this type of stone.

Obsidian is a 'volcanic glass' that forms and it has sharp edges and can be used in cutting tools.

There are many uses for igneous rock and about 95% of the Earth's crust is made up of this rock.  Do some research and find out a few uses of this rock.

Watch the video and have some fun in the kitchen (be careful)