These rocks form when magma reaches the Earth's surface and cools. When magma reaches the Earth's surface, it is called lava. If the lava cools slowly, it will form crystals. This rock can be broken down by the process of weathering and erosion. If broken down, it will become sediments.

Sedimentary rocks are made when sediments are packed together.Most sedimentary rocks are found near bodies of water. They can carry fossils. Most sedimentary rocks look like layer cake.

This rock started as a sedimentary rock. The sedimentary rock is covered by many layers of sediment. These layers push the rock deeper into the Earth. In the Earth the rock begins to heat up. Pressure and friction cause this heat. After many years of heat and pressure,the sedimentary rock turns into metamorphic rock.