sedimentary
Coal
Combustible Sedimentary Rock
AI-generated identification · may be incorrectHardness 1.5 to 2.5 on Mohs scale, black to dark brown color, dull to submetallic luster, amorphous structure, specific gravity 1.2 to 1.5.
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Physical properties
Hardness 1.5 to 2.5 on Mohs scale, black to dark brown color, dull to submetallic luster, amorphous structure, specific gravity 1.2 to 1.5.
Formation & geological history
Formed from compressed plant debris in ancient swamp environments over hundreds of millions of years during the Carboniferous period.
Uses & applications
Primarily used for electricity generation, industrial steel production, and historical heating.
Geological facts
Coal represents ancient solar energy captured by prehistoric plants through photosynthesis and stored underground.
Field identification & locations
Identified by its lightweight feel, black streak, and dirty residue on fingers; commonly found in sedimentary basins worldwide.
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