Editing Iron(III) oxide (section)

===Polishing===
A very fine powder of ferric oxide is known as "jeweler's rouge", "red rouge", or simply rouge. It is used to put the final polish on metallic [[jewellery|jewelry]] and [[lens (optics)|lenses]], and historically as a [[rouge (cosmetics)|cosmetic]]. Rouge cuts more slowly than some modern polishes, such as [[cerium(IV) oxide]], but is still used in optics fabrication and by jewelers for the superior finish it can produce. When polishing gold, the rouge slightly stains the gold, which contributes to the appearance of the finished piece. Rouge is sold as a powder, paste, laced on polishing cloths, or solid bar (with a [[wax]] or [[petroleum|grease]] binder). Other polishing compounds are also often called "rouge", even when they do not contain iron oxide. Jewelers remove the residual rouge on jewelry by use of [[ultrasonic cleaning]]. Products sold as "[[stropping (blade)|stropping]] compound" are often applied to a [[razor strop|leather strop]] to assist in getting a razor edge on knives, straight razors, or any other edged tool.