Ferric Oxide Yellow
This is one of the many colors of iron oxide. Yellow ochre clay contains yellow iron oxide. In ceramics, red iron oxide is most commonly used in glazes and clay bodies, but black is also used. Yellow is the least stable form of the color. Iron oxide yellow is a synthetic material with a very fine particle size (but not as fine as black or red).

Yellow iron can be used when the original color or other original properties are important to the manufacturing process or color of the unfired product and when a less messy material is desired. Yellow iron is not as fluffy or light as black iron, but it is fluffier and lighter than red iron. It is not as heavily agglomerated as red, but more so than black. It has a coarser particle size and does leave some light-colored residue on a 325-mesh sieve (up to 8% residue in one sample we tested and zero in others).

Pyrite is also used in paints, enamels, concrete stains, plastics, rubber and paper where a permanent yellow color is desired. It has excellent hiding power, absorbs UV light, is compatible with a wide range of vehicles, disperses well in aqueous and solvent systems, and is free of heavy metals.