“What type of rock is this?” is a common question spoken by all children at some point in their young lives. Many students have rocks of all shapes and sizes in their “collections.” In this column, young students will have the opportunity to explore more in depth as they make observations of the three types of rocks—igneous, metamorphic, and sedimentary. Upper-grade students who have some previous study of rocks can use these books to review what they know of the rock cycle.