Summary:
- The appearance of the rock is created by the composition of the magma.
- The size of the crystals creates the texture of theRock.
- The most common extrusive igneous rock is basalt.
- It is the rock that makes up the ocean floor.
- The rapid cooling time does not allow time for large crystals to form.
- So igneous extrusive rocks have smaller crystals than igneous intrusive rocks.
- Extrusive.
- igneous rocks are also called volcanic rocks.
- They cool from magma slowly in the crust.
- They have large crystals.