sedimentary

Anthracite Coal

Anthracite (Carbon-rich Sedimentary Rock)

AI-generated identification · may be incorrect

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

Hardness: 2

Identified May 11, 2026More sedimentary →

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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.