Anthracite Coal

Physical Properties

Hardness: 2.5-3.0 (Mohs scale); Color: Black to steel-gray; Luster: Submetallic to vitreous (glassy); Crystal structure: Amorphous; Cleavage: None (conchoidal fracture); Specific gravity: 1.3–1.8

Formation & Geological History

Formed through the regional metamorphism of bituminous coal. It undergoes intense pressure and heat, typically during mountain-building events (orogenies), removing most volatiles. Much of Earth's coal formed during the Carboniferous period (300-360 million years ago).

Uses & Applications

Primary use is for domestic and industrial heating because it burns with a clean blue flame and high energy output. It is also used as a filter medium in water purification and occasionally in jewelry (mourning jewelry or carvings).

Geological Facts

Anthracite is the highest rank of coal, containing between 86% and 98% carbon. It is much rarer than other types of coal, accounting for less than 1% of total coal reserves.

Field Identification & Locations

Identify in the field by its high luster (very shiny compared to other coal), lack of soot when handled, and its hardness (it doesn't crumble easily). Predominantly found in the Appalachian mountains of Pennsylvania, USA, as well as parts of China, Russia, and Ukraine.

Identified on: 4/18/2026

Mode: Standard