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
Hayden (given name) Hayden (given name) Hayden is a given name in the English language. The name is variant of the given name "Haydn", which is derived from the surname "Haydn" in honour of composer Joseph Haydn (1732–1809). The surname "Haydn" originated as a respelling of the nickname "Heiden", meaning "". The name is derived from the Middle High German "heiden", and from the Old High German "heidano". The form "Haydn" was generally considered a masculine given name up until the mid 20th century. The popularity of "Hayden" has been influenced by the popularity of similar-sounding names such as "Aidan", "Braden", "Caden", and