Anthracite Coal

Physical Properties

Hardness: 2.5-3 (Mohs scale), Color: Jet black to dark gray, Luster: Sub-metallic to brilliant, Structure: Amorphous/microcrystalline, Specific Gravity: 1.3-1.8

Formation & Geological History

Forms through the highest grade of coalification (metamorphism of peat/bituminous coal) under high pressure and temperature, typically dating back to the Carboniferous period around 300 million years ago.

Uses & Applications

Primarily used as a residential and industrial fuel due to high energy density and low smoke. High-quality specimens are used for carving, jewelry (Jet), and water filtration.

Geological Facts

Anthracite is known as 'hard coal' and has the highest carbon content (often over 90%) of all coal types. It burns with a blue flame and is considered the cleanest burning coal.

Field Identification & Locations

Identify by its deep black color, high luster (glassy look), and lack of soot when handled compared to other coals. Found in folded mountain belts like the Appalachians.

Identified on: 5/11/2026

Mode: Standard