Coal is a black or brownish-black sedimentary rock that can be burned!

Normally it is found in layers called coal beds or coal seams. Coal is made of of carbon along with small amounts of other elements.

Coal begins as layers of plant matter accumulating at the bottom of a body of water. For the process to continue, the plant matter must be protected from rotting, usually by mud or acidic water. This traps their carbon in immense peat bogs that are eventually covered over and deeply buried by sediments. Under this compression the plant material is turned into coal.

The wide shallow swamps of the Carboniferous period provided ideal conditions for coal formation, although coal is known from most geological periods. Coal is even known from Precambrian strata, which predate land plants: this coal is presumed to have originated from algae.

Coal, a fossil fuel, is the largest source of energy for the generation of electricity worldwide. Coal is extracted from the ground by mining, either underground by shaft mining through the seams or in open pits.


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