sedimentary
Anthracite Coal
Anthracite (Carbon-rich Sedimentary Rock)
Hardness: 2.5-3 (Mohs scale), Color: Jet black to dark gray, Luster: Sub-metallic to brilliant, Structure: Amorphous/microcrystalline, Specific Gravity: 1.3-1.8
- 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: 2.5-3 (Mohs scale), Color: Jet black to dark gray, Luster: Sub-metallic to brilliant, Structure: Amorphous/microcrystalline, Specific Gravity: 1.3-1.8
Formation & geological history
Forms through the highest grade of coalification (metamorphism of peat/bituminous coal) under high pressure and temperature, typically dating back to the Carboniferous period around 300 million years ago.
Uses & applications
Primarily used as a residential and industrial fuel due to high energy density and low smoke. High-quality specimens are used for carving, jewelry (Jet), and water filtration.
Geological facts
Anthracite is known as 'hard coal' and has the highest carbon content (often over 90%) of all coal types. It burns with a blue flame and is considered the cleanest burning coal.
Field identification & locations
Identify by its deep black color, high luster (glassy look), and lack of soot when handled compared to other coals. Found in folded mountain belts like the Appalachians.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary