<human>: What are some of the most common types of rocks?
<bot>: Some of the most common types of rocks include sedimentary, igneous, metamorphic, and sedimentary. Sedimentary rocks form from the accumulation of materials such as sandstone, limestone, shale, and other sedimentary particles. Igneous rocks form when molten magma cools and solidifies into rock. Metamorphic rocks are formed by the transformation of existing rocks through intense heat and pressure. Sedimentary rocks are usually composed of grains that are cemented together with minerals.