sedimentary

Anthracite Coal

Anthracite

Hardness: 2.5-3 (Mohs); Color: Black or brownish-black; Luster: Submetallic, vitreous; Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Fracture: Conchoidal

Hardness: 2
Color: Black or brownish-black
Luster: Submetallic, vitreous

Identified July 3, 2026More sedimentary →

Explore Anthracite Coal in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 2.5-3 (Mohs); Color: Black or brownish-black; Luster: Submetallic, vitreous; Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Fracture: Conchoidal

Formation & geological history

Formed through the burial and intense pressure/heat of peat and lower-grade coal over millions of years (metamorphism of sedimentary organic matter). Found in folded mountain belts commonly associated with the Carboniferous period.

Uses & applications

Used primarily for heating, fuel for power generation, and specialized industrial filtration systems. Historically used as a cleaner-burning coal for steam engines.

Geological facts

Anthracite has the highest carbon content (86-97%) and the highest energy density of all coal types. It is often referred to as 'hard coal' because of its density and shiny appearance.

Field identification & locations

Identify by its shiny, jet-black appearance, lack of soot when handled compared to bituminous coal, and its characteristic conchoidal (shell-like) fracture pattern. Found in abundance in regions like Pennsylvania, USA.