Terminology
Other terms which refer to anthracite are black coal, hard coal, stone coal (not to be confused with the German Steinkohle or Dutch steenkool which are broader terms meaning all varieties of coal of a stonelike hardness and appearance, like bituminous coal and often anthracite as well, as opposed to lignite, which is softer), blind coal (in Scotland), Kilkenny coal (in Ireland), crow coal (or craw coal from its shiny black appearance), and black diamond. "Blue Coal" is the term for a once-popular and trademarked brand of anthracite, mined by the Glen Alden Coal Company in Pennsylvania, and sprayed with a blue dye at the mine before shipping to its northeastern U.S. markets to distinguish it from its competitors. The imperfect anthracite of north Devon and north Cornwall (around Bude) in England, which is used as a pigment, is known as culm. Culm is also the term used in geological classification to distinguish the strata in which it is found and similar strata in the Rhenish hill countries are known as the Culm Measures. In America, culm is used as an equivalent for waste or slack in anthracite mining.
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