Rhodium is a precious metal, a member of the platinum family. Rhodium electroplating is used on jewelry to provide a surface that will resist scratches and tarnish, and give a white, reflective appearance.
Rhodium plating is most often found on white gold. The term white gold is something of a misnomer. Gold is actually yellow. What jewelers call white gold is a mixture of gold and a white metal – usually nickel, silver, or palladium (another member of the platinum family).
Metals known as white are actually more of a gray color, so white gold has a yellowish cast. The more gold there is in the mixture, the more yellow the cast appears.
Since the wearer of white gold is looking for a bright white look, a very thin layer of rhodium electroplating is used to make that jewelry shine. White gold plated with rhodium will also keep its good looks longer - rhodium will not tarnish or discolor, and since it is a harder substance, it is much less likely to get scratched.
Rhodium plating does not last forever. Plating on something that takes a lot of wear and tear, like a wedding ring, can wear away in as little as two years. An item worn less frequently like a pin or necklace, or one that comes in contact with your skin or the elements less, can keep its plating for ten or more years.
You can tell when the plating is wearing away by the look of the piece; the area without the plating will show the yellowish color of the original white gold.
Most jewelry items can be easily replated, although replating a two-toned piece will be more expensive because the work needs to be done by hand. Prices will vary according to the thickness of the plateing that you choose to use. Choose thicker layers for items you wear every day, like a wedding or engagement ring. The extra expense will be well worth.
Replating will not fill in dents, dings and scratches, it will only make them shinier and more noticeable! Have your jewelry cleaned and polished before you have it replated. The smoother the piece is to start with, the better the effect you will get from the process.
Sometimes, platinum or silver jewelry is rhodium-plated. In the case of platinum, it is because rhodium is a bit brighter than platinum, so it is used to enhance the shine. For silver, it is a little bit different. Silver is actually more reflective (shinier) than rhodium, but silver is also a much softer metal, and can be scratched very easily. So you get to choose a small bit of shine for a longer life or a scratch-free life. When the plating begins to wear away from a platinum or silver piece, it will be much less noticeable because the color difference is not far from the color of the metal underneath.