sedimentary

Anthracite Coal

Anthracite (Carbon-rich metamorphic sedimentary rock)

AI-generated identification · may be incorrect

Hardness: 2.5-3.0 Mohs; Color: Jet black to dark grey; Luster: Sub-metallic to vitreous; Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Conchoidal fracture.

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

Identified April 2, 2026More sedimentary →

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Physical properties

Hardness: 2.5-3.0 Mohs; Color: Jet black to dark grey; Luster: Sub-metallic to vitreous; Structure: Amorphous (non-crystalline); Specific Gravity: 1.3-1.8; Conchoidal fracture.

Formation & geological history

Formed from the accumulation of plant matter in swamps during the Carboniferous period (300-360 million years ago), subjected to high heat and pressure during mountain building (orogeny).

Uses & applications

Primarily used as a high-grade fuel for domestic heating and industrial steam generation; also used in metallurgy and as a filtration medium for water purification.

Geological facts

Anthracite contains the highest carbon content of all coals (86% to 97%) and has the fewest impurities. It burns with a short blue flame and very little smoke.

Field identification & locations

Identify by its deep black color, shiny metallic-like surface, and the fact that it does not soil fingers when touched (unlike bituminous coal). Often found in folded mountain belts like the Appalachians.