sedimentary
Coal (Anthracite or Bituminous)
Lithified plant matter (Carbon)
Hardness: 0.5-2.5 (Mohs), Color: Black to dark brown, Luster: Dull to sub-metallic, Crystal Structure: Amorphous, Cleavage: None/Conchoidal fracture, Specific Gravity: 1.1-1.5
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Physical properties
Hardness: 0.5-2.5 (Mohs), Color: Black to dark brown, Luster: Dull to sub-metallic, Crystal Structure: Amorphous, Cleavage: None/Conchoidal fracture, Specific Gravity: 1.1-1.5
Formation & geological history
Formed from the accumulation of plant remains in swampy environments (peat) that were buried and subjected to heat and pressure over millions of years (Carboniferous era).
Uses & applications
Primarily used as a solid fuel for electricity generation, industrial heating, and as a raw material for steel production (coke).
Geological facts
Anthracite coal is the highest rank of coal and has the highest carbon content, often appearing slightly shiny. Coal is frequently referred to as a 'fossil fuel'.
Field identification & locations
Identify by its lightweight feel compared to stone, black streak, and tendency to leave black residue on hands. Often found near rail tracks or in sedimentary basins.
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