A name used to describe many different mixtures of hydrocarbons, also called asphalt or tar, bitumen is the brown or black viscous residue from the vacuum distillation of crude petroleum. Often produced by the processing of coal or oil, used in asphalt or tar for road surfacing or waterproofing. It also occurs in nature as asphalt "lakes" and "tar sands." It consists of high molecular weight hydrocarbons and minor amounts of sulfur and nitrogen compounds.
See also: Asphalt.