Is Petroleum a Mineral? (+ 3 Facts You Should Know)

Petroleum is not considered a mineral. It is an organic substance derived from the remains of ancient organisms, primarily marine microorganisms, and it lacks the necessary criteria of being a naturally occurring inorganic substance with a defined crystal structure. ¹

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Why is petroleum not a mineral?

Petroleum, also known as crude oil, is not considered a mineral because it does not meet the criteria that define minerals. Minerals are naturally occurring inorganic substances with a specific chemical composition and a crystalline structure. They are typically formed through geological processes over long periods of time. ²

Petroleum, on the other hand, is a complex mixture of hydrocarbons that is derived from the remains of ancient plants and animals. It is formed through a process called diagenesis, where the organic matter is subjected to heat and pressure over millions of years.

This process transforms the organic material into hydrocarbons, which accumulate in porous rocks, such as sandstone or limestone, to form oil reservoirs.

While petroleum is extracted from the Earth like many minerals, it lacks the crystalline structure and specific chemical composition characteristic of minerals.

Instead, it is a mixture of various hydrocarbons, including different types of molecules such as alkanes, cycloalkanes, and aromatic compounds. ³ This liquid mixture does not possess the ordered arrangement of atoms found in minerals.

Therefore, petroleum is considered a fossil fuel rather than a mineral due to its organic origin, complex composition, and lack of crystalline structure.

How is petroleum different from minerals?

Petroleum and minerals differ in several key aspects, including their formation, composition, physical properties, and uses. Here are some of the primary differences between petroleum and minerals:

• Formation: Minerals are naturally occurring inorganic substances that form through geological processes. ⁴ They often result from the solidification of molten rock (magma) or the precipitation of minerals from solution. Petroleum, on the other hand, is derived from the remains of ancient plants and animals that have undergone a process of decomposition and transformation over millions of years. ⁵
• Composition: Minerals have a specific chemical composition and a crystalline structure. They consist of elements or compounds arranged in an ordered, repetitive pattern. In contrast, petroleum is a complex mixture of hydrocarbons, which are organic compounds made up of hydrogen and carbon atoms. ⁶ It contains a range of different hydrocarbon molecules, including alkanes, cycloalkanes, and aromatic compounds.
• Physical Properties: Minerals exhibit a wide variety of physical properties, such as hardness, color, luster, cleavage, and specific gravity. These properties vary depending on the chemical composition and crystal structure of the mineral. Petroleum, being a liquid mixture of hydrocarbons, has different physical properties. It is typically a viscous liquid with a range of colors, from clear to dark brown or black. It has a lower density than most minerals and is combustible.
• Extraction and Use: Minerals are mined from the Earth’s crust through various methods, such as underground mining, open-pit mining, or extraction from sediments. They are used for a wide range of purposes, including construction, manufacturing, energy production, and as raw materials in various industries. Petroleum, on the other hand, is extracted through drilling wells into oil reservoirs deep underground. ⁷ It is a vital energy resource and serves as a major source of fuel for transportation, heating, and electricity generation.

In summary, while minerals are inorganic substances with a specific chemical composition and crystalline structure, petroleum is an organic mixture of hydrocarbons derived from ancient organic matter. Minerals have diverse physical properties and are used for various industrial applications, while petroleum serves as a crucial energy resource.

How is petroleum formed?

Petroleum is formed from the remains of ancient marine organisms such as algae and zooplankton. ⁸ Over millions of years, these organic materials accumulate in ocean sediments and undergo heat and pressure, transforming into hydrocarbons and forming petroleum reservoirs deep underground.

In more detail, petroleum formation begins with the deposition of organic material, primarily microscopic marine organisms, in sedimentary basins such as ancient lakes or oceanic environments.

As these organisms die, their remains settle at the bottom of bodies of water, where they mix with inorganic sediments and gradually become buried under layers of sediment.

Over time, the organic material undergoes a process called diagenesis, which involves the biochemical and physical transformation of the organic matter under increased temperature and pressure. ⁹

This process leads to the conversion of the organic material into hydrocarbons, primarily through the thermal cracking of complex organic molecules.

As the sedimentary layers continue to accumulate and bury the organic-rich material deeper, the increasing temperature and pressure cause the hydrocarbons to migrate and accumulate in porous rocks such as sandstone or limestone, forming petroleum reservoirs.

These reservoirs are typically found deep underground, often trapped beneath impermeable layers of rock, where they can be accessed through drilling wells for extraction.

It is important to note that petroleum formation is a complex and geologically lengthy process, taking millions of years. ¹⁰ The specific conditions, such as the organic material composition, burial depth, and geological history of an area, influence the quantity and quality of petroleum that is ultimately formed.

Further reading

Is Lithium a Mineral?
Is Sulfur a Mineral?
Is Wood a Mineral?
Is Gold a Mineral?
Is Coal a Mineral? 

About author

Jay Rana

Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.

Read more about our Editorial process.

1. Petroleum. (n.d.). Petroleum. https://education.nationalgeographic.org/resource/petroleum
2. Mineral. (n.d.). Mineral. https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/m/Mineral.htm
3. Petroleum – Wikipedia. (2016, October 1). Petroleum – Wikipedia. https://en.wikipedia.org/wiki/Petroleum
4. What is the difference between a rock and a mineral? | U.S. Geological Survey. (2019, February 25). What Is the Difference Between a Rock and a Mineral? | U.S. Geological Survey. https://www.usgs.gov/faqs/what-difference-between-rock-and-mineral
5. Si.edu https://ocean.si.edu/conservation/gulf-oil-spill/what-are-fossil-fuels
6. Types of Petroleum Oils | US Environmental Protection Agency. (n.d.). Types of Petroleum Oils | US Environmental Protection Agency. https://archive.epa.gov/emergencies/content/learning/web/html/oiltypes.html
7. Finding oil and natural gas deep underground. (n.d.). Main. https://energy.mit.edu/news/finding-oil-natural-gas-deep-underground/
8. Oil formation – Energy Education. (n.d.). Oil Formation – Energy Education. https://energyeducation.ca/encyclopedia/Oil_formation
9. Diagenesis – Wikipedia. (n.d.). Diagenesis – Wikipedia. https://en.wikipedia.org/wiki/Diagenesis
10. Ku.edu https://www.kgs.ku.edu/Publications/Oil/primer02.html