Coal

Coal is a fossil fuel extracted from the ground by underground mining or open-pit mining (surface mining). It is a readily combustible black or brownish-black sedimentary rock. It is composed primarily of carbon along with assorted other elements, including sulfur. Often associated with the Industrial Revolution, coal remains an enormously important fuel. It is the largest single source of fuel for the generation of electricity world-wide, and a vital component in the reduction of iron ore.
Coal