sedimentary
Anthracite Coal
Anthracite (Metamorphic/High-grade Coal)
AI-generated identification · may be incorrectHardness: 2.7-3.0 Mohs, Color: Jet black to dark steel-gray, Luster: Bright sub-metallic to vitreous, Fracture: Conchoidal, Specific Gravity: 1.3-1.8, Density: High for coal
- Hardness
- 2
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Physical properties
Hardness: 2.7-3.0 Mohs, Color: Jet black to dark steel-gray, Luster: Bright sub-metallic to vitreous, Fracture: Conchoidal, Specific Gravity: 1.3-1.8, Density: High for coal
Formation & geological history
Formed through the intense heat and pressure (low-grade metamorphism) acting on plant matter and peat over hundreds of millions of years, primarily during the Carboniferous period.
Uses & applications
Used historically as a clean-burning high-energy fuel for heating and metallurgy; also used in water filtration systems and as a gemstone/carving material (like jet).
Geological facts
Anthracite is the highest rank of coal, containing 86% to 97% carbon. It produces a very hot, blue, smokeless flame when burned.
Field identification & locations
Identified by its shiny, glassy jet-black appearance, relative hardness compared to soft bituminous coal, and non-sooty feel when handled. Commonly found in eastern Pennsylvania, USA.
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