A mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a mineral source, particularly a distillate of petroleum. Most often, mineral oil is a liquid by-product of refining crude oil to make gasoline and other petroleum products. This type of mineral oil is a transparent, colorless oil composed mainly of alkanes and cycloalkanes, related to petroleum jelly. It has a density of around 0.8 g/cm3.
Mineral oil is used in a variety of industrial/mechanical capacities as a non-conductive coolant or thermal fluid in electric components as it does not conduct electricity, while simultaneously functioning to displace air and water. Some examples are in transformers where it is known as transformer oil, and in high voltage switchgear where mineral oil is used as an insulator and as a coolant to disperse switching arcs.