coal science definition

A dark-brown to black solid substance formed from the compaction and hardening of fossilized plant parts in the presence of water and in the absence of air. Carbonaceous material accounts for more than 50 percent of coal's weight and more than 70 percent of its volume. Coal is widely used as a fuel, and its combustion products are used as raw material for a variety of products including cement, asphalt, wallboard and plastics. See more at anthracite, bituminous coal, lignite.