coal

Coal is a hard rock which can be burned as a solid fossil fuel. It is mostly carbon but also contains hydrogen, sulphur, oxygen and nitrogen. It is a sedimentary rock formed from peat, by the pressure of rocks laid down later on top.

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post #5507380
↑19♥9C0S
post #5491371
↑3♥3C1S
post #5491369
↑2♥1C0S
post #5483482
↑5♥5C4S