Ferric Oxide

Ferric Oxide, also known as iron (iii) oxide and ferrous monoxide, is a dark red inorganic powder with the formula Fe₂O₃. It is a common pigmentation additive that is used in a variety of industries including glass, personal care, and ceramic glazes and enamels.

Agriculture
Ferric oxide is used as a fertilizer as a source of iron. Plants that require larger amounts of iron also tend to prefer more acidic soils. Such plants include berries, leafy greens, and root vegetables.

Metallurgical
Ferric oxide is added to iron, steel, and a variety of metal alloy feed stock.

Personal Care
Black iron oxide is an inorganic pigment material, valued for its inert stability and hypoallergenic properties. It finds use in products such as: eye shadow, lipstick, nail polish, and semi-permanent tattoos.

Additional Notes:
* When firing in oxidation, ferric oxide is refractory.
* Ferric oxide is also called rust by some people, although chemists will usually refer to rust as hydrated ferric oxide.
* Ferric oxide has many polymorphic forms.
* Can be found as the mineral hematite (link).
* Other popular uses for ferric oxide include jewelry polishing, and along with zinc oxide, is the active ingredient in calamine lotion (0.5%).