How does bituminous coal differ from anthracite?

Bituminous coal and anthracite differ primarily in their rank, chemical composition, and physical properties, which are determined by the degree of coalification they have undergone.12

• Composition: Anthracite is the most highly metamorphosed form of coal, containing 86 percent or more fixed carbon and the least amount of volatile matter (14 percent or less). Bituminous coal is intermediate in rank, generally containing lower percentages of fixed carbon and higher levels of volatile matter compared to anthracite.342
• Physical Appearance: Anthracite is hard, brittle, and black to steel gray with a brilliant, metallic luster. Bituminous coal is typically dark brown to black and often appears banded or layered.34
• Combustion and Use: Bituminous coal is the most abundant form of coal and is widely used for electric power generation and the production of metallurgical coke due to its ability to soften and swell (agglomerate) when heated. Anthracite is difficult to ignite but burns slowly with a pale blue flame; it is cleaner to the touch than bituminous coal but is less abundant and more costly.423