Coal is an example of

Coal is an example of Sedimentary rocks. Coal is a biochemical sedimentary rock because coal is formed from organic matter or sediment that comes from biological processes. Coal is typically found near swampy areas, or areas where sediment has little contact with oxygen. Plant matter that dies and settles to the bottom of the swamp will often be processed by bacteria. Bacteria will often take out the oxygen and hydrogen within the substance and leave the carbon. If this substance is buried deep and hardens, it will become coal.