Igneous rocks are divided into two groups. The first one is extrusive igneous rocks or volcanic rocks. These rocks are made from lava that comes out of an erupted volcano.

The other type of igneous rock is called intrusive igneous rocks or plutonic rocks. These are rocks that have formed beneath the Earth's surface.

Sedimentary Rocks

Sedimentary rocks are formed from one or more different types of rocks that have been cemented, weathered, or pressed together. They are formed by sediments such as smaller pieces of rock, mud, and sand. After much time, the sediments squeeze or compress together and then more sediments compress together on top of that and so on. This forms strata or layers that are all compressed together to make sedimentary rocks. Good places for us to see sedimentary rocks are river banks, cliffs, road cuts, and quarries. Some types of sedimentary rocks are sandstone, shale, and limestone.