Iron oxide is any one of a range of chemical compounds made up of iron and oxygen. Most of these are naturally occurring; some form in the soil or in chemical deposits in rocks or mountains, and rust is also a very common and well-known source. Not all oxides are useful to humans, but several varieties play key roles in industry, cosmetics, and art. Manufacturers often rely on them to add pigment as well as to provide certain electronic and magnetic properties to things like bankcards and digital scanning devices.

Where it Comes From

Iron is a metallic element with the chemical symbol Fe, and is one of the most prolific and commonly occurring mineral substances on Earth. Scientists estimate that is found in approximately 5% of the planet's crust, and exists in its core, too. Iron turns to iron oxide when it comes into contact with oxygen, either on its own or in combination with other elements like water. When the mineral is exposed to water and air for extended periods of time it will usually produce rust, which is a reddish-brown oxide.

Deposits of iron oxide occur in the soil, too. Experts usually believe that these were created by the precipitation of iron from seawater during the Proterozoic Eon some 1.6 billion years ago. These deposits are found in locations around the world, though the greatest concentrations tend to be in what is now the United States, India, Australia, China, Brazil, and Russia.

Use in Electronics

Among stable, room temperature elements, there are usually only three that are naturally magnetic, namely cobalt, nickel, and iron; among these, iron is usually the most magnetic, which manufacturers often capitalize on in the production of magnets, electronic parts, audio and video cassette tapes, and bank and magnetized credit cards. In these cases a bit of powdered oxide is combined with other elements and sealants to create magnetic tapes or bands that can be used to help keep working parts charged and in place. That the oxide occurs naturally in nature helps keep costs down, too.

Importance in Art

In the art world, iron oxide is used to create pigments such as burnt sienna and burnt umber. Colors and paints made this way tend to be permanent and long lasting. Though the precise method of coloring paints has changed somewhat over time, the basic concept has been at play since the prehistoric age; the cave paintings at Lascaux, France, are just one example of how long this compound has been used and how well paints made with iron last. Modern manufacturers rarely rely on italone to form base colors and pigment foundations, though it is often still an important ingredient.

In Industry

The compound in its various types and combinations has a range of different uses in industry. Pigments are frequently used to dye such things as commercial-grade paint, concrete, leather, and shoe polish, for example; products like tiles and rubber sometimes also contain it for color and stability. Iron oxide is also added to different nutrients, feeds, and medications in trace amounts, usually as a way of maintaining chemical balance between different active ingredients.