sedimentary
Coal
Bituminous Coal
AI-generated identification · may be incorrectHardness 2-2.5 on Mohs scale, black or brownish-black color, dull to submetallic luster, amorphous crystal structure, uneven fracture, specific gravity 1.3-1.4.
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Physical properties
Hardness 2-2.5 on Mohs scale, black or brownish-black color, dull to submetallic luster, amorphous crystal structure, uneven fracture, specific gravity 1.3-1.4.
Formation & geological history
Formed from compressed plant debris in ancient swamp environments over hundreds of millions of years, primarily during the Carboniferous period.
Uses & applications
Historically used as a primary fossil fuel for electricity generation, steel production, and heating.
Geological facts
Coal contains stored solar energy captured by ancient plants via photosynthesis over 300 million years ago.
Field identification & locations
Easily identified by its lightweight feel, black streak, and tendency to soil the fingers. Commonly found in sedimentary coal-bearing rock strata worldwide.
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