A white gold ring that has started to look faintly yellow, grey or patchy has, in almost every case, not changed metal. What has changed is a surface layer. Most white gold leaves the workshop plated with rhodium, a bright white metal, and the colour people notice after months or years of wear is the gold alloy underneath showing through where that layer has thinned. This guide explains what rhodium is, why it is there, what US law says about disclosing it, and what it does and does not change about the piece.
White gold is not white on its own
Gold is yellow, and no alloy changes what the gold itself is. White gold is gold mixed with metals that pale its colour, usually nickel or palladium, often with silver, copper or zinc as well. The karat is still the gold content by weight: 18K white gold is 750 parts per thousand gold, exactly as 18K yellow gold is, and 14K is 585 as stamped. What the other metals do is cancel most of the yellow. They do not cancel all of it. Even well-made white gold alloys come out a pale grey or a faintly warm white, not the cold bright white of a newly bought ring. The gold alloy colour guide explains how the alloying metals shift colour, and why exact recipes differ from maker to maker.
What rhodium is
Rhodium is a chemical element, symbol Rh, atomic number 45. It is one of the six platinum-group metals, alongside platinum, palladium, ruthenium, iridium and osmium. It is white, very reflective, hard and resistant to tarnish, which makes it well suited as a finish. It is not normally used to make jewellery on its own; in jewellery it appears almost entirely as a thin electroplated coating.
Plating a white gold piece with rhodium gives it the bright white finish that the alloy alone does not have. On nickel-containing white gold, the plating also covers the alloy’s surface, which matters to anyone with a nickel sensitivity for as long as the plating is intact; the nickel allergy guide covers that in detail. Rhodium is also used over sterling silver to resist tarnish, and in a dark form, often sold as black rhodium, as a decorative finish.
Why it wears, and why it shows
A plated layer is thin by nature, and anything that rubs against the piece removes a little of it: the palm side of a ring band, the edges of a setting, the back of a pendant where it sits against skin or clothing. As the layer thins, the alloy beneath begins to show, first at the points of most contact. The yellow or grey cast is the white gold’s own colour, not tarnish and not a sign the gold is less than its stamp.
How long rhodium plating lasts depends on how thick it was applied and how the particular piece is worn, and neither is recorded on the piece. There is no published standard interval for replating, and this site does not give one: any single figure would be a guess presented as a fact. A jeweller can replate white gold, which restores the finish without changing the metal underneath.
What US law says about disclosing rhodium
The Federal Trade Commission’s Guides for the Jewelry, Precious Metals, and Pewter Industries deal with rhodium in a single sentence, at 16 CFR § 23.7. It is unfair or deceptive to fail to disclose a surface-layer application of rhodium on products marked or described as precious metal. In plain terms: if a ring is sold as white gold, or silver, or any other precious metal, and it has been rhodium plated, the seller in the US is expected to say so.
The rule concerns disclosure. It does not require a mark on the metal, and there is no standard stamp for rhodium plating on white gold, so the inside of a ring will usually show only the karat or fineness. The disclosure, where there is one, tends to be in the description or paperwork rather than on the piece. Rhodium-plated pieces are white gold, silver or whatever their stamp says; the plating does not turn them into platinum, and the US rules on platinum marks do not allow a coated item to be described as platinum on the strength of its finish.
Telling a worn white gold ring from something else
- Look at where the colour is. Wear shows first on high and inner surfaces, with the more protected areas still bright. Colour that is even across the whole piece is less likely to be worn plating.
- Read the stamp. A karat or fineness mark, 585, 750, 14K, 18K, is a claim about the gold content, and it is unaffected by plating. The hallmark reference explains what each mark claims.
- Do not judge by colour alone. Plated base metal can look the same as plated white gold. Colour says nothing about what is under the surface; the stamp, the weight and, if it matters, a test by a jeweller or assay office do.
Plating and melt value
Melt value is the gold in a piece at the live price: weight, minus any stones, times the fineness of the alloy. The rhodium is a surface coating, not part of the alloy, and the gold calculator does not count it. A worn ring and a freshly plated one of the same weight and karat contain the same gold. What a buyer offers for either is a different question from what the gold is worth at spot; the melt value guide explains why those two numbers are kept apart on this site.
If the colour is the reason for wanting to compare white gold with other metals, the white gold vs platinum guide sets out how the two are made and how each wears over time.