Anthracites are a type of dark, hard coal that is high in carbon content and glossy in appearance. Synonyms for anthracites include hard coal, black coal, stone coal, and anthracite coal. The term hard coal is often used interchangeably with anthracites, but it can also refer to any type of high-carbon content coal. Black coal is another common synonym that is used to describe any coal that has a dark color and high carbon content. Stone coal is a regional term that is used to describe anthracites in certain parts of the world, and anthracite coal is a technical term that specifically refers to the highest grade of coal with a carbon content of 86% or higher.