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 budgerigar mutation now be determined. It seems likely that the Anthracite is the re-emergence of the English Grey. A bird with two Anthracite factors has an extremely dark grey body, jet black markings and the cheek patches of the same very dark grey as the body. G W von Kamrath describes them as "jet black wing and tail markings and deep black cheek patches". A single Anthracite factor has a similar effect to the Dark mutation, causing a Skyblue to become Cobalt in appearance. The Anthracite mutation appeared in Germany in 1998 in the aviaries of Hans-Jürgen H Lenk, who successfully established