Polishing metals

The process used by jewellers, of making metal smooth and glossy, after the piece has been fashioned and rubbed with any of various abrasives to give it its preliminary finishing. The polishingis done first by machine, using a polishing lathe fitted with various polishing brushes charged with emery powder and oil or with tripoli, and then by lathe or hand, using a polishing mop charged withtripoli, or rouge, after which the piece is completed by buffing with a buff stick. Small areas are polished by burnishing. Polishing the interior of a finger ring is done with either a felt coneattached to the spindle on the lathe or a ring-stick.

Polishing gemstones

The polishing of gemstones is done on a rotating wheel (scaife) charged with various powders, including tripoli, putty powder, diatomite, rottenstone, and pumice. It is sometimes followed by an acidbath. A diamond requires no special polishing, as the stone, having no Beilby layer, is polished in the same operation as the faceting.