Much of Earth is comprised of rock, from the continents people live on to the melted rock within the core of the planet. Rock comes in a variety of shapes, sizes, and compositions, notably including sedimentary, igneous, and metamorphic. Readers learn about the natural processes that create each type through accessible fact boxes and a helpful graphic organizer detailing the parts of the cycle. Vivid photographs enhance the reading experience and contribute a visual element to an important part of the STEM curriculum.