Natural resources are materials and substances that occur naturally in the environment. GAS, OIL, ORE, and mineral deposits are all examples of natural resources. GAS is a combustible mixture of hydrocarbons, primarily methane, used as fuel. OIL is a thick, black liquid composed of hydrocarbons that is found in certain rock formations beneath the Earth's surface. ORE is a mineral or rock from which a valuable metal or mineral can be extracted. A mineral deposit is an accumulation of valuable minerals formed by natural geological processes.