Coal is the most abundant fossil fuel. It forms when dead and decaying plants are buried in swamps and marshes. Over time, as the material is buried, increased temperature and pressure convert it into peat, then lignite, then bituminous coal, and finally, anthracite coal.
Provided by Pittsburgh Research Center,
Bureau of Mines, Pittsburgh, Pennsylvania
Topic: Earth Science
Subtopic: Minerals and Resources
Keywords: Minerals, Mineralogy, Coal