Sedimentary rock may be broken down into sediment once again by weathering and erosion. It may also form another type of rock. If it becomes buried deep enough within the crust to be subjected to increased temperature and pressure, it may change into metamorphic rock. Deep inside the Earth, intense heat and pressure can change rocks into entirely new metamorphic rocks. In fact, the conditions are so extreme; they can change the rock's texture, color, and the shape of its crystals.