- Crude oil - Fossil fuel - Fuel for most cars - Rock oil, mineral oil, or natural oil, a dark brown or
greenish inflammable liquid, which, at certain points, exists in the
upper strata of the earth, from whence it is pumped, or forced by
pressure of the gas attending it. It consists of a complex mixture of
various hydrocarbons, largely of the methane series, but may vary much
in appearance, composition, and properties. It is refined by
distillation, and the products include kerosene, benzine, gasoline,
paraffin, etc.