Anthracite

Physical Properties

Hardness: 2-3 Mohs; Color: Black or very dark gray; Luster: Submetallic to metallic; Crystal Structure: Amorphous (hydrocarbon-based); Cleavage: Uneven or conchoidal fracture; Specific Gravity: 1.3-1.8

Formation & Geological History

Formed through the metamorphic transformation of bituminous coal under intense heat and pressure. Most significant deposits date to the Carboniferous period (about 300 million years ago) in areas of complex tectonic folding.

Uses & Applications

Primarily used for heating and power generation due to high carbon content and low impurities; also used in water filtration, metallurgy, and occasionally as 'jet' in jewelry (though true jet is related to lignite).

Geological Facts

Anthracite contains the highest percentage of carbon (86%-98%) and the lowest amount of volatiles of all coal types. It burns with a short blue flame and produces very little smoke or soot.

Field Identification & Locations

Identify by its shiny, almost metallic black surface and the fact that it does not soil fingers as much as lower grades of coal. Commonly found in Pennsylvania, USA, South Wales, and parts of China.

Identified on: 5/1/2026

Mode: Standard