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 iron technique & process, which he had conceived in an attempt to improve the efficiency of conventionally fueled furnaces. The first person to employ the hot blast technique to anthracite smelting was Dr. Frederick W. Gesenhainer, who filed for a patent on the process in 1831 and received it in 1833. In 1836, he tried smelting anthracite iron on a practical scale at his property, Valley Furnace, near Pottsville, Pennsylvania, while in the same year White & Hazard's LC&N Co. built two experimental blast furnaces in Mauch Chunk. He produced a small quantity of iron, but due to mechanical breakdowns, could