Anthracite Mohs scale), its higher relative density of 1.3–1.4, and luster, which is often semi-metallic with a mildly brown reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed. Anthracitization is the transformation of bituminous coal into anthracite. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. The heat content
Carbon steel Carbon steel Carbon steel is a steel with carbon content up to 2.1% by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels. As the carbon percentage content rises, steel has the ability to become harder and stronger through heat treating; however, it becomes less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.