Crude oil

From GAWDAwiki

Crude oil is a naturally-occurring substance found in certain rock formations in the Earth. It is a dark, sticky liquid that is classified as a hydrocarbon, a compound containing carbon and hydrogen, with or without non-metallic elements such as oxygen and sulfur. Crude oil is highly flammable and can be burned to create energy. Along with its fellow hydrocarbon, natural gas, derivatives from crude oil make fuel.^[1].

References

1. http://www.opec.org/library/FAQs/CrudeOil/q1.htm