Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than anthracite. It was usually formed as a result of high pressure on lignite. Bituminous coal is an organic sedimentary rock formed by diagenetic and sub metamorphic compression of peat bog material. Bituminous coal has been compressed and heated so that its primary constituents are macerals vitrinite, exinite, and so on. The carbon content of bituminous coal is around 60-80%; the rest is composed of water, air, hydrogen, and sulphur, which have not been driven off from the macerals.
Contributions by Vsmith, Edgar181, and Rolinator.