sedimentary
Coal
Bituminous or Anthracite coal (carbon-rich sedimentary rock)
Hardness: 0.5-2.5 on Mohs scale; Color: black to brownish-black; Luster: dull to sub-metallic/glassy; Structure: amorphous or microcrystalline; Cleavage: none (cleat/fracture)
- Hardness
- 0
- Color
- black to brownish-black
- Luster
- dull to sub-metallic/glassy
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Physical properties
Hardness: 0.5-2.5 on Mohs scale; Color: black to brownish-black; Luster: dull to sub-metallic/glassy; Structure: amorphous or microcrystalline; Cleavage: none (cleat/fracture)
Formation & geological history
Formed from the accumulation and burial of plant remains in swampy environments over millions of years, subjected to heat and pressure (coalification).
Uses & applications
Primary source of fuel for electricity generation, industrial heat, and production of coke for steel manufacturing.
Geological facts
Coal is the most abundant fossil fuel on Earth; it contains stored energy from plants that lived hundreds of millions of years ago in swampy forests.
Field identification & locations
Identified by its lightweight feel, black streak, and tendency to smudge hands. Often found in layered beds or seams within sedimentary basins.
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