Bituminous Coal

Organic Sedimentary Rock (Carbon-based)

Rock Type: sedimentary

Bituminous Coal

Physical Properties

Hardness: 0.5-2.5 (Mohs scale), Color: Black or dark brown, Luster: Dull to sub-metallic, Crystal Structure: Amorphous (organic matter), Cleavage: None (conchoidal fracture), Specific Gravity: 1.2-1.5

Formation & Geological History

Formed through the burial and heating of peat under high pressure over millions of years (primarily Carboniferous era). It is a stage of coalification between lignite and anthracite.

Uses & Applications

Primarily used for electricity generation (thermal coal) and steel production (coking coal). Occasionally used by blacksmiths or for historical recreation.

Geological Facts

It is the most abundant rank of coal found in the United States. It contains between 45% and 86% carbon. In some cultures, it was given as a token of luck during New Year celebrations.

Field Identification & Locations

Identify by its layered (banded) appearance, dull black color, and the fact that it soils the fingers when handled. Found in sedimentary basins such as the Appalachian region.

Identified on: 5/19/2026

Mode: Standard