Igneous rocks form when magma cools and hardens. Magma reaches the earth's surface through volcanoes. If magma cools inside the volcano, the igneous rock formed is intrusive; if it cools on the surface, the rock is extrusive. Intrusive rocks have larger crystals due to slower cooling, while extrusive rocks have smaller or no crystals due to faster cooling at the surface. Examples given are the extrusive rocks basalt, obsidian, and pumice, as well as the intrusive rock granite.

1. All you need to know

2. 
Ingneous rocks are made from lava that is
cooled down and hardened.

3. 

Igneous rocks are made from magma that is
cooled down and hardened.
Once the magma is cooled it is called lava

4. 
The magma reaches the earth’s surface from
a volcano.

5. 

The magma reaches the earth’s surface from
a volcano.
The rock either cools inside or outside the
volcano
Rocks cool
outside
Rocks cool
inside
Where magma
Is kept

6. 
Igneous rocks cooled inside a volcano are
called intrusive
Rocks cool
outside
Rocks cool
inside
Where magma
Is kept

7. 

Igneous rocks cooled inside a volcano are
called intrusive
Igneous rocks cooled outside a volcano are
called extrusive
Rocks cool
outside
Rocks cool
inside
Where magma
Is kept

8. 
The rocks inside the volcano have larger
crystals because they cool slower.
Large crystals
Intrusive Igneous
Rock

9. 

The rocks inside the volcano have larger
crystals because they cool slower.
The Rocks outside the volcano have small
crystals because they cool faster. Some have
no crystals at all
Little crystals
Extrusive igneous
Rock

10. 
Here are some examples you need to know.
You must know if they are extrusive or
intrusive as well.

11. 



Here are some examples you need to know.
You must know if they are extrusive or
intrusive as well.
The first one is Bassalt
It is extrusive
It is cooled fast but has some crystals

12. 


The Next one is Obsidean
It is Extrusive
It has no crystals

13. 





The Next one is Obsidean
It is Extrusive
It has no crystals
The Next one is Pumice
It is extrusive
It is very light and is holy

14. 



The last is called granite
It is Intrusive
It has large crystals
It is used for benchtops