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
Anthracite budgerigar mutation the Anthracite locus. This darkens the body colour to a shade somewhat deeper than a Dark Green. The DF Anthracite Light Green, with two Anthracite alleles, is a deep olive colour. In the blue series varieties the SF Anthracite Skyblue has one Anthracite allele and one wild-type allele, with a body colour rather like a deep Cobalt. The DF Anthracite Skyblue with two Anthracite alleles, the true Anthracite variety, has a dark grey, almost black, body colour with mauve overtones. Because the Anthracite factor is always visibly expressed no budgerigar can be split for Anthracite. The heterozygotes of Anthracite with