There is a material on Earth that undergoes a very long, and sometimes violent, cycle. This material can begin as a solid on the surface of the Earth. Weathering can then break the material up into pieces, and erosion can transport the pieces to ocean bottoms. Eventually, the material reforms as these pieces are cemented together. Over time, the material is gradually pushed into the Earth's interior. Heat from inside the Earth can then cause the material to melt. Eventually, the melted material returns back to the surface through volcanic eruptions. At the surface, the material cools and turns solid once again. What is this material?