Used as a pigment in paints, coatings, and construction materials due to its stable red-brown color. Commonly found in rust-proof primers because it helps prevent corrosion on steel surfaces. Employed in polishing agents for glass and metals, known as jeweler’s rouge. Acts as a catalyst in industrial processes like the Haber-Bosch and water-gas shift reactions. Utilized in thermite mixtures for welding and cutting metals. Added to magnetic storage media and toners for its magnetic properties. Also used in biomedical applications such as drug delivery systems and MRI contrast enhancement when in nanoparticle form.