What is the Difference Between Magnesia and Magnesium

Magnesia and magnesium are closely related substances with various applications across various industries. Magnesia is magnesium oxide (MgO), a compound composed of magnesium and oxygen while magnesium is a metallic element with atomic number 12.

What is the difference between magnesia and magnesium? Magnesia is a compound containing magnesium, while magnesium is the elemental form of the metal itself.

Key Areas Covered

1. What is Magnesia  
      – Definition, Features 
2. What is Magnesium
      – Definition, Features 
3. Similarities Between Magnesia and Magnesium
      – Outline of Common Features
4. Difference Between Magnesia and Magnesium
      – Comparison of Key Differences
5. FAQ: Magnesia and Magnesium
      – Answers to Frequently Asked Questions

Key Terms

Magnesia, Magnesium

Difference Between Magnesia and Magnesium - Comparison Summary

What is Magnesia

Magnesia, also known as magnesium oxide (MgO), is a compound primarily derived from magnesite, a naturally occurring mineral abundant in various parts of the world, including China, Russia, and Australia. One of the most notable properties of magnesia is its high melting point, making it an essential component in refractory materials used in industries such as steelmaking, ceramics, and glass production. Its ability to withstand high temperatures and harsh environments makes it invaluable in these applications, where it serves as a lining material for furnaces, kilns, and other high-temperature vessels.


In addition to its role in refractories, magnesia is also utilized in the manufacturing of magnesium metal through a process called the Pidgeon process. This process involves the reduction of magnesium oxide with ferrosilicon in a high-temperature reaction, resulting in the production of magnesium metal—a crucial material in the automotive, aerospace, and electronics industries.

Beyond industrial applications, magnesia finds use in various other sectors, including agriculture, healthcare, and environmental remediation. In agriculture, magnesia-based fertilizers are employed to replenish magnesium levels in soils, promoting healthy plant growth. In healthcare, magnesia is used as an antacid to relieve indigestion and heartburn, thanks to its alkaline properties. Furthermore, it serves as a laxative when ingested orally.

Moreover, magnesia plays a role in environmental remediation efforts, particularly in the treatment of wastewater and acidic soils. Its alkaline nature helps neutralize acidity, making it effective in mitigating environmental pollution.

What is Magnesium

Magnesium is a mineral that plays an important role in numerous physiological functions within the human body. It is involved in over 300 biochemical reactions, which makes it essential for overall health and well-being. This mineral is primarily found in bones, muscles, and soft tissues, where it contributes to their structure and function.

One of magnesium’s primary roles is its involvement in energy production. It participates in ATP (adenosine triphosphate) synthesis, the body’s primary energy currency, by activating enzymes involved in the metabolism of carbohydrates and fats. This makes it indispensable for maintaining optimal energy levels and supporting physical performance.


Magnesium also plays a key role in muscle function and relaxation. It helps regulate muscle contractions by balancing calcium levels within cells. Adequate magnesium levels are necessary for proper muscle contraction and relaxation, which is crucial for activities ranging from simple movements to athletic performance.

Additionally, magnesium is involved in maintaining cardiovascular health. It helps regulate blood pressure by relaxing blood vessels and supporting heart function. Low magnesium levels have been linked to an increased risk of hypertension and cardiovascular diseases.

Beyond its physiological functions, magnesium is also important for bone health. It aids in the absorption and metabolism of calcium, another essential mineral for bone strength. Thus, maintaining adequate magnesium levels is crucial for preventing osteoporosis and bone fractures.

Similarities Between Magnesia and Magnesium

  1. Both magnesia (MgO) and magnesium (Mg) contain the element magnesium.
  2. Both are used in various industrial applications.

Difference Between Magnesia and Magnesium


  • Magnesium refers to the element with the atomic number 12, while magnesia typically refers to magnesium oxide (MgO), a compound composed of magnesium and oxygen.


  • Magnesium exists as a metallic element, often found in the form of alloys or as pure magnesium metal. Magnesia, on the other hand, typically exists as a white solid, either in the form of a powder or as a crystalline substance.


  • Magnesium metal exhibits metallic properties such as conductivity, malleability, and ductility. Magnesia, being an oxide compound, is non-metallic and possesses properties such as high melting point, refractoriness, and alkalinity.


In conclusion, while both magnesia (MgO) and magnesium (Mg) contain the essential element magnesium and are used in various industrial applications, they differ significantly in their chemical composition and properties. Magnesia, primarily magnesium oxide, serves diverse functions from industrial refractories to healthcare and environmental remediation. On the other hand, magnesium, as a vital mineral within the human body, contributes to energy production, muscle function, cardiovascular health, and bone strength.

FAQ: Magnesia and Magnesium

1. What is the main use of magnesia?

The main use of magnesia is to alleviate symptoms caused by excessive stomach acid, including heartburn, upset stomach, and indigestion. It acts as an antacid, neutralizing stomach acid to provide relief from discomfort. Additionally, magnesia may also be used as a laxative to relieve constipation.

2. Are manganese and magnesium the same?

No, manganese and magnesium are not the same. Magnesium is an essential mineral found in abundance in the Earth’s crust and is useful for various biological functions in humans, plants, and animals. Manganese is also a metallic element but serves different purposes, such as in the production of steel and other alloys, as well as in certain chemical processes.

3. Can manganese replace magnesium?

Manganese ion (Mn(2+)) can substitute magnesium ion (Mg(2+)) in active sites of numerous enzymes. This substitution can occur in various biological processes, potentially affecting enzyme activity and function.

4. Which type of magnesium is best?

Magnesium glycinate is often considered one of the best forms of magnesium due to its high bioavailability. It is created by combining magnesium with the amino acid glycine, which enhances absorption in the body. This form of magnesium is less likely to cause gastrointestinal discomfort compared to other forms.

5. What are the symptoms of magnesium deficiency?

Symptoms of magnesium deficiency can manifest in various ways, including low appetite, nausea, and vomiting, along with feelings of fatigue and weakness. Symptoms may also include muscle spasms or tremors and abnormal heart rhythms.


1. “Magnesium.” Encyclopedia Britannica. 
2. “Magnesium Oxide.” Wikipedia. Wikipedia Foundation.

Image Courtesy:

1. “Magnesium oxide” ByWalkerma assumed  – No machine-readable source provided. Own work assumed (based on copyright claims). (Public Domain) via Commons Wikimedia
2. “CSIRO ScienceImage 2893 Crystalised magnesium” By CSIRO (CC BY 3.0) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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