sedimentary
Anthracite Coal
Anthracite (Metamorphic/High-grade Coal)
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
- Hardness
- 2
Identified More sedimentary →
Explore Anthracite Coal in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
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.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary