sedimentary

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

AI-generated identification · may be incorrect

Hardness: 2-2.5 (Mohs scale), Color: Jet black to dark grey, Luster: Sub-metallic to vitreous (glassy), Structure: Amorphous/microcrystalline, Specific Gravity: 1.3–1.8, Conchoidal fracture

Hardness: 2-2

Identified July 17, 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: 2-2.5 (Mohs scale), Color: Jet black to dark grey, Luster: Sub-metallic to vitreous (glassy), Structure: Amorphous/microcrystalline, Specific Gravity: 1.3–1.8, Conchoidal fracture

Formation & geological history

Formed through the regional metamorphism of sedimentary coal beds. It requires high temperature and pressure, typically during mountain-building events, and takes millions of years to develop from peat and bituminous coal.

Uses & applications

Used primarily as a high-grade fuel for heating and industrial processes due to its high carbon content and low impurities; also collected as a mineral specimen.

Geological facts

Anthracite is the highest rank of coal, containing between 86% and 97% carbon. Unlike other coals, it burns with a clean blue flame and produces very little smoke or soot.

Field identification & locations

Identify by its shiny, almost metallic black surface and the way it breaks into curved (conchoidal) shards. It is much cleaner to touch than softer coals. Common in northeastern Pennsylvania and other mountainous coal regions.