sedimentary

Anthracite coal

Anthracite; predominantly carbon (C), with minor mineral impurities

AI-generated identification · may be incorrect

Hardness about 2.5–3 Mohs; black to steel-gray, bright submetallic luster, irregular blocky fracture, and very fine-grained structure. It is dense, brittle, and usually shows little clay or visible layering.

Identified August 12, 2026More sedimentary →

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Physical properties

Formation & geological history

A high-rank metamorphic coal formed when bituminous coal was subjected to intense heat and pressure, typically during mountain building. It commonly formed in Carboniferous coal basins, roughly 359–299 million years ago.

Uses & applications

Used as a high-temperature fuel, smokeless domestic heating coal, reducing agent in metallurgy, and occasionally as a carbon source for water filtration. It has little jewelry value.

Geological facts

Anthracite has the highest fixed-carbon content and lowest volatile matter of ordinary coal, commonly around 86–97% carbon. It burns with a short blue flame and produces relatively little smoke.

Field identification & locations

Identify it by its hard, shiny black appearance, high density, and conchoidal-to-blocky fracture; it generally does not smear easily like softer bituminous coal. Major sources include Pennsylvania, Vietnam, Russia, China, and Wales.