1) Petroleum is not a mineral because minerals have to be solid. However petroleum is a "mineral resource": "Mineral resources, geological deposits (crystalline, non-crystalline, solid, liquid or gas) which potentially can be mined." Source and further information: http://en.wikipedia.org/wiki/Mineral_(disambiguation%29 Also "mineral oil" is a by-product in the distillation of petroleum. 2) "A mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific chemical composition. Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms. The study of minerals is called mineralogy. To be classified as a true mineral, a substance must be a solid and have a crystalline structure. It must also be a naturally occurring, homogeneous substance with a defined chemical composition. Traditional definitions excluded organically derived material. However, the International Mineralogical Association in 1995 adopted a new definition: a mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes. The modern classifications include an organic class – in both the new Dana and the Strunz classification schemes." "The organic mineral class includes biogenic substances in which geological processes have been a part of the genesis or origin of the existing compound. Minerals of the organic class include various oxalates, mellitates, citrates, cyanates, acetates, formates, hydrocarbons and other miscellaneous species. Examples include whewellite, moolooite, mellite, fichtelite, carpathite, evenkite and abelsonite." Source and further information: http://en.wikipedia.org/wiki/Mineral 3) "Mineral oil or liquid petroleum is a by-product in the distillation of petroleum to produce gasoline and other petroleum based products from crude oil. It is a transparent, colorless oil composed mainly of alkanes (typically 15 to 40 carbons) and cyclic paraffins, related to petroleum jelly (also known as "white petrolatum"). It has a density of around 0.8 g/cm3.[1] Mineral oil is a substance of relatively low value, and it is produced in very large quantities. Mineral oil is available in light and heavy grades, and can often be found in drug stores. In the late 1800s, the term "mineral oil" or "rock oil" was first used to describe the petroleum hydrocarbons and associated products that were produced from wells that tapped underground reservoirs. The term differentiated petroleum hydrocarbons produced from underground sources from other common oil sources at the time, such as palm oil or whale oil. In today's petroleum exploration and production (E&P) business, the phrase "mineral oil" is most often used in legal documents to define and encompass all of the liquid hydrocarbon and gaseous products produced from wells drilled into underground petroleum-bearing reservoirs." Source and further information: http://en.wikipedia.org/wiki/Mineral_oil