Letter 11387

Expensive ring ruined in three days 

Hi,

I bought my Fiancee a white gold ring about two weeks ago, only about three days after she had worn it small spots began to appear on the surface. My first thought was that she had possibly spilled/sprayed a chemical on the ring. But she hadn't, the ring was very expensive and I am beginning to wonder if I have made a mistake on the ring purchase. The jeweler told me about the plating but made it sound as if it would last a long time and that the plating was not a big deal, I am not out any money but very upset. Why did this ring get spots so fast? ( the ring had to be sized before I bought it, could this have done it?)

Ben Tindall
- Lexington, KY, USA

Hi Ben,there is a very good chance your white gold ring was plated with a metal called rhodium. Most of the 14kt white gold sold in the U.S is an alloy of yellow gold and nickel (palladium is used sometimes instead of nickel). In both cases the natural color is more toward a gray white color (some alloys are yellowish gray). Rhodium is plated over the white gold to color enhance the "whiteness" of white gold. When done correctly,(I.e. clean surface, proper thickness) rhodium plating can be made quite durable. I own several rhodium plated cigarette lighters from the late 1930's that are as bright and lusterous as when new.

Without the advantage of seeing the actual ring, there could be several reasons for the surface discoloration. However, there is a high probability that your ring was not properly cleaned after it was sized. Just prior to plating, residue from soldering flux or other contaminants(polishing compound) may have been present on the areas where the spots are. Contaminants will prevent the rhodium from being deposited on the white gold. Contaminants from leftover from the pickling solution (removes scales and oxides after soldering)could also be the culprit.

In many jewelry operations rhodium is "pen plated" after the repair process. Regretably, many jewelers are not necessarily good at providing durable plated finishes. They also have a tendency to use too thin a layer of rhodium due to the technical limitations of their plating chemicals,processes and equipment. If the rhodium is too thin porosity in the rhodium will allow contaminants to "filter" through the openings in the rhodium layer and react with the nickel in the white gold. This is especially troublesome if the wearer is sensitized to nickel and develops a skin allergy. Nevertheless, Ben plan on having your ring replated every 2 years or so.

I would recommend you take it back and insist on a quality replate of rhodium. Also get a memo in writing guaranteeing the plating will last for at least 2 years. That in itself will be a testament to the jewelers self confidence in their own plating capabilites.

Good Luck,

David Vinson Metal Arts Specialties Leonard, Michigan

Sight unseen it sounds like a horrifically bad plating job. See "FAQ: White Gold Alert!"

Ted Mooney, P.E.  finishing.com Brick, New Jersey

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