What is the Difference Between Red and Black Iron Oxide?

The main difference between red and black iron oxide lies in their composition, color, and magnetic properties. Here are the key differences:

• Composition: Red iron oxide has the chemical formula Fe₂O₃, while black iron oxide has two forms: FeO and Fe₃O₄.
• Color: Red iron oxide occurs as a red-brown powder, while black iron oxide is black in color. The color of red iron oxide changes from light pinkish to red to dark purplish-red as the particle size increases. Black iron oxide changes color at 365°F (180°C) from black to brown to red as it oxidizes.
• Magnetic Properties: Red iron oxide is ferromagnetic, while black iron oxide is ferrimagnetic.

Both red and black iron oxides are used in various applications, such as ceramics, pigments, and coatings. The choice between the two depends on the desired color, magnetic properties, and specific requirements of the application.

Comparative Table: Red vs Black Iron Oxide

The main difference between red and black iron oxide lies in their color, composition, and magnetic properties. Here is a table comparing the two:

Red iron oxide, also known as ferric oxide, has the chemical formula Fe2O3 and is a major oxide of iron. It is called "hematite" in mineralogy and is the main source of iron for the steel industry. Black iron oxide, also known as magnetite, has the chemical formula Fe3O4 and is a type of iron ore that is rich in iron (Fe) content and can be magnetized. Both red and black iron oxides are important components in the chemical industry and are naturally occurring minerals.