Human: How can I tell if a rock is metamorphic or sedimentary? Assistant: 
Metamorphic rocks are formed when existing rocks are transformed by heat and pressure. They often have a banded or layered appearance due to the different minerals that were present in the original rock. Sedimentary rocks, on the other hand, are made up of particles that have been deposited over time by wind or water. These sediments are then cemented together by minerals such as calcite, silica, and clay.