What is Jewellers rouge ?

Jeweller's rouge is a very fine powder of ferric oxide, also known as iron(III) oxide with the chemical formula Fe2O3 [t4][t5]. It is widely used as a polishing compound to provide a final high-gloss finish on metallic jewelry, lenses, and glass [t6][t9]. Chemically, it is the stable alpha-phase of iron oxide, which is less aggressive than other abrasives like chromium oxide or aluminum oxide, making it ideal for delicate polishing without excessive metal removal [t8][t10]. While other oxides of iron exist, such as ferrous oxide (iron(II) oxide, FeO), they are typically black and more reactive, whereas ferric oxide is the characteristic red powder associated with 'rouge' (the French word for red) [t1][t2][t3]. It is also the primary component of hematite and common rust [t2][t3].