Rocks are categorized into three types: igneous, sedimentary and metamorphic. This classification is based on the manner of rock formation. Igneous rocks solidify from a hot molten material called magma. Sedimentary rocks are formed through erosion and deposition processes. Metamorphic rocks are rocks that are exposed and altered due to extreme heat and pressure.
Granite is a type of intrusive igneous rock that crystallized beneath Earth's surface. Due to its mineral constitution, granite comes in a variety of colors, such as red, pink, white or gray. Granite is also characterized by its rough texture. Natural granite formations include the Stone Mountain in Georgia and Mount Rushmore in South Dakota.Learn more about Geology