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bituminous coal
Sign in to saveAlso known as Anthracite, soft coal, hard coal
often greasy, shiny, combustible organic sedimentary rock that consists of more than 75 per cent carbon by weight
~16 min read
Encyclopedic overview
Bituminous coal
Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It is typically hard but friable. Its quality is ranked higher than lignite and sub-bituminous coal, but lesser than anthracite. It is the most abundant rank of coal, with deposits found around the world, often in rocks of Carboniferous age. Bituminous coal is formed from sub-bituminous coal that is buried deeply enough to be heated to 85 °C (185 °F) or higher.
Excerpted from Wikipedia’s “bituminous coal” article, available under the CC BY-SA 4.0 licence.