Used as a catalyst in organic synthesis, particularly in oxidation and nitration reactions. Employed in the production of iron oxide pigments for paints, ceramics, and coatings due to its ability to provide consistent color and stability. Serves as a mordant in dyeing processes to enhance color fastness on textiles. Applied in analytical chemistry for detecting the presence of thiocyanates and other compounds through colorimetric methods. Also utilized in etching and metal surface treatment processes to modify surface properties or remove impurities. Additionally, used in wastewater treatment to remove phosphates by precipitation as iron phosphate.