Learn About Jewelry Technology & Manufacturing

Finishing

Generally, with few exceptions, all Jewelry needs to be polished at the end of the manufacturing process. Traditionally, this is done on polishing wheels impregnated with polishing compounds such as jewelers rouge. This is labor intensive and consistency of quality cannot be controlled. In mass production and in the more progressive workshops, increasing use is being made of mechanized polishing methods. These involve tumbling the Jewelry mixed in with abrasive shapes or with polishing compounds and also by burnishing (hammering) the surface with hard materials such as steel pins and cones or porcelain balls. Generally, polishing is achieved in a series of polishing steps. Typical equipment includes tumblers (rotating barrels), vibratory barrels, centrifugal disc machines ('turbo'), centrifugal planetary barrels and magnetic burnishers. Electropolishing (electrostripping) is also practiced. Robots for polishing rings are now commercially available:

Other surface textures such as satin or matt finishes can be produced by various techniques such as sand blasting, vibratory pens and diamond machining. Chemical methods such as acid treatment or 'bombing' in a cyanide-hydrogen peroxide mixture are also practiced. This can enhance the color to the deep yellow of pure gold by preferentially dissolving away the base metal and silver from the surface layer as well as giving a good finish.

Top of Page