Anthracite is a hard, solid form of coal that has a high carbon content and low moisture content. It is known for its high energy content and burns with a clean blue flame. In terms of relative hardness, anthracite is considered to be one of the hardest varieties of coal, ranking above bituminous coal and lignite in terms of its resistance to breakage and wear. On the Mohs scale of mineral hardness, anthracite has a hardness level of approximately 2.2-2.9, which is relatively low compared to many other minerals and rocks. However, it should be noted that the hardness of anthracite can vary depending on its specific composition and impurities.
