Rhodium

Rhodium electroplating

Rhodium is a very bright, hard, and highly reflective metal. When applied by an electrochemical process to white gold or platinum it forms a hard, white, highly reflective surface to the metal.

Rhodium has an extraordinary resistance to most acids and corrosive substances. It is one of the few 'white' metals that will remain bright and reflective under all atmospheric conditions at ordinary temperatures.

It should be noted that rhodium electroplating does not hide surface imperfections. In fact, due to the diffusive reflection of incidental light rays, pre-existing cosmetic imperfections are even more noticeable on a brightly plated surface. Items are therefore highly polished prior to rhodium plating.

The only disadvantage of rhodium-plating white gold is that the plating eventually wears off at a rate that depends on the wear-and-tear to which the item is subjected, exposing the yellowish-gray white gold alloy beneath. The ring may therefore need to be re-plated later (at a nominal fee of $20 - $30). The need for continued maintenance of white gold is often the main reason many customers cite for investing extra money into a platinum engagement ring or wedding band.

Although platinum jewelry is also usually rhodium plated, the underlying gray-white platinum is similarly colored to rhodium and therefore wear-and-tear on the jewelry does not result in a less than white color.