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
Energy value of coal Energy value of coal The energy value of coal, or the fuel content, is the amount of potential energy in coal that can be converted into actual heating ability. The value can be calculated and compared with different grades of coal or even other materials. Materials of different grades will produce differing amounts of heat for a given mass. While chemistry provides methods of calculating the heating value of a certain amount of a substance, there is a difference between this theoretical value and its application to real coal. The grade of a sample of coal does not precisely define