Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Coal is a combustible black or brownish-black sedimentary rock made up mostly of carbon. It forms from the remains of plants that lived and died millions of years ago.
Related terms
Fossil Fuel: Fossil fuels are non-renewable energy sources formed from organic matter buried in the Earth's crust over millions of years.