Earth's rocky crust has three types of rocks: sedimentary, igneous, and metamorphic. The rock cycle describes how rocks transform from one type to another. Combinations of different minerals make up different kinds of rocks. People use many kinds of rocks in many different ways. Marble, granite, and quartz are valued for their uses in making statues and buildings, Sand and gravel are commonly used for concrete and road building. These printables describe the rock cycle, the different types of rocks, and the ways people use rocks and minerals.