Video narration
Can a rock really become a different kind? Think of an ice cube: water can melt, then freeze again, taking a new form. Rocks have three main kinds, sorted by how they form. Igneous rocks form when melted rock cools and hardens-underground, that melted rock is magma; at the surface, it's lava. Granite and basalt are examples. Sedimentary rocks form as sediments settle in layers, then compact and cement together. Sandstone and limestone are examples. Metamorphic rocks begin as existing rocks changed by intense heat and pressure. They don't melt; they change while staying solid. Marble and slate are examples. But these kinds aren't sealed boxes. Limestone can become marble, shale can become slate, and granite can become gneiss-separate examples of rocks changing. So, can a rock become another kind? Yes. Rocks can become other kinds over time; that ongoing process is the rock cycle.