Rautaferrioksidi

Rautaferrioksidi, also known as iron(III) oxide or hematite, is a chemical compound with the formula Fe2O3. It is one of the most abundant minerals on Earth's surface and is a primary ore of iron. Rautaferrioksidi is a dark gray to black solid with a metallic luster. It is a type of oxide, a compound containing oxygen, and is classified as a ferric oxide due to the presence of iron in its +3 oxidation state.

The mineral form of rautaferrioksidi is known as hematite and is often found in sedimentary, metamorphic, and igneous rocks. It is also a common component of soil and is responsible for the red color of rust. Rautaferrioksidi is used in various applications, including as a pigment in paints and ceramics, as a catalyst in chemical reactions, and as a component in magnetic materials.

Rautaferrioksidi has several polymorphs, including alpha-Fe2O3 (hematite), beta-Fe2O3 (maghemite), and gamma-Fe2O3 (maghemite). Each polymorph has distinct physical and chemical properties. Hematite is the most stable and common form at room temperature and pressure.

Rautaferrioksidi is produced industrially through the oxidation of iron ores, typically using the Bayer process. The compound is also formed during the corrosion of iron and steel, a process known as rusting. The formation of rautaferrioksidi is a complex process involving the oxidation of iron and the hydrolysis of iron(III) ions.