Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare, and iron(II,III) oxide (Fe3O4), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main source of iron for the steel industry. Fe2O3 is readily attacked by acids. Iron(III) oxide is often called rust, and to some extent this label is useful, because rust shares several properties and has a similar composition.
Ferric oxide is one of the oxides of iron. It is also known as iron (III) oxide and its chemical formula is Fe2O3. It is an inorganic compound. The other two oxides of iron are iron (II) oxide having the chemical formula FeO and iron (II,III) oxide having the chemical formula Fe3O4.
Iron oxides are commonly available chemical compounds composed of iron (Fe) and oxides and are mainly used in the form of iron ores, pigments, catalysts, etc. Iron oxides are produced from both natural and synthetic resources. Natural iron oxides are mainly derived from (1) hematite (Fe2O3), a red iron oxide mineral, (2) limonites (FeOOH), which in colour vary from yellow to brown, such as ochers, siennas and umbers, and (3) magnetite (Fe3O4), a black iron oxide.
Iron oxide pigments are durable colored pigments used in various applications such as constructions, industrial coatings, varnishes, paper, fertilizers, and plastics. These are nontoxic inorganic pigments composed of iron oxides and oxyhydroxides with relatively economical prices. Iron oxide pigments are of two types namely synthetic or natural. The basic property that differentiates synthetic iron oxide pigments from the natural is the purity level, which is lower in natural iron oxide pigments. The level of contamination defines the working efficiency of these pigments.