Rocks can be classified into three main types: igneous, metamorphic, and sedimentary.
Use the table below to identify the characteristics of different types of rock:
Igneous Rock: rocks formed by the cooling and solidifying of molten materials. Igneous rocks can form beneath the Earth’s surface, or at its surface, as lava.
Sedimentary Rock: rock that has formed through the deposition and solidification of sediment, especially sediment transported by water, ice, and wind. Sedimentary rocks are often deposited in layers, and frequently contain fossils.
Metamorphic Rock: rock that was once one form of rock but has changed to another under the influence of heat or pressure without passing through a liquid phase.