What are the different classes of rocks called?
If you mean the different types, there are sedimentary,
metamorphic, and igneous. Sedimentary is formed when layers and
layers of sediment are cemented together. During the process of
metamorphism, no new substance is formed. The rock is compressed by
heat or scolding water, and pressure. That is how metamorphic rock
is formed. Lastly, igneous rock is formed when magma and/or lava
cools and hardens. An example of sedimentary rock is limestone. A
metamorphic, slate. A good example of igneous is granite, and
everyone knows what that is.