metamorphic

Anthracite Coal

Anthracite (Hard Coal)

AI-generated identification · may be incorrect

Hardness: 2.5-3.0; Color: Jet black; Luster: Sub-metallic to vitreous; Structure: Amorphous/Compact; Cleavage: Conchoidal fracture; Specific Gravity: 1.3-1.8

Hardness: 2
Color: Jet black
Luster: Sub-metallic to vitreous

Identified July 12, 2026More metamorphic →

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Physical properties

Hardness: 2.5-3.0; Color: Jet black; Luster: Sub-metallic to vitreous; Structure: Amorphous/Compact; Cleavage: Conchoidal fracture; Specific Gravity: 1.3-1.8

Formation & geological history

Formed through the low-grade metamorphism of bituminous coal under high pressure and temperature. Primarily formed during the Carboniferous period (300-360 million years ago) in swampy environments.

Uses & applications

Used historically for domestic heating and industrial fuel; in modern times, it is used for charcoal filters, water purification, and as a component in steel making.

Geological facts

Anthracite is the highest rank of coal, containing the highest carbon content (86-97%) and the fewest impurities. It burns with a short blue flame and produces very little smoke.

Field identification & locations

Identified by its shiny, glass-like appearance and tendency not to soil fingers like softer coals. Found in folded mountain belts like the Appalachians in Pennsylvania, USA.