Anthracite Cornwall, which was used as a pigment. The term is also used to refer to some Carboniferous rock strata found in both Britain and in the Rhenish hill countries (the Culm Measures). Lastly, it may refer to coal exported from Britain during the 19th century. In American English, "culm" refers to the waste or slack from anthracite mining, mostly dust and small pieces not suitable for use in home furnaces. Anthracite is similar in appearance to the mineraloid jet and is sometimes used as a jet imitation. Anthracite differs from ordinary bituminous coal by its greater hardness (2.75–3 on the
Anthracite high energy per its weight and burns cleanly with little soot, making it ideal for this purpose. Its high value makes it prohibitively expensive for power plant use. Other uses include the fine particles used as filter media, and as an ingredient in charcoal briquettes. Anthracite is an authorised fuel in terms of the United Kingdom's Clean Air Act 1993, meaning that it can be used within a designated Smoke Control Area such as the central London boroughs. China today mines by far the largest share of global anthracite production, accounting for more than three-quarters of global output. Most Chinese