White gold

Gold is naturally yellow, so white gold gets its colour from the white metals alloyed with it. Palladium, silver, nickel and zinc are the usual ones, and the example recipes in the table below, from the World Gold Council, contain no nickel.

They show the range. White 14K is about 58.3% gold, 32.2% silver and 9.5% palladium. White 18K is 75% gold and 25% palladium, or platinum. C. W. Corti, writing for the Assay Office London, describes two commercial kinds of white gold, one whitened mainly with nickel and one with palladium. Nickel gives hard alloys and palladium gives soft, malleable ones, he writes, so the white metal changes how the piece behaves, not just how it looks.

The World Gold Council describes nickel-containing white golds as a small share of white gold alloys, generally with copper and zinc added. Metallurgist C. W. Corti reports that many commercial 14K and 18K white golds are made with both nickel and palladium. The two views differ on how common nickel is, which is a good reason to ask about the recipe.

White gold is usually plated with rhodium for a whiter look, a brighter shine and a harder surface that resists scratching. Many commercial white golds are not a good white on their own, so the plating supplies the colour. Rhodium is a white metal, and the layer is thin.

The layer wears away gradually, so white gold needs occasional re-plating; how often depends on the alloy and how hard the ring is worn. This is the main upkeep difference from yellow gold. As the plating thins, the ring may start to look warmer in colour because the alloy beneath shows through. The layer can be renewed by plating again; the rhodium plating entry explains how. How fast it wears depends on how the piece is worn.

It depends on the alloy. Some white gold contains nickel, and people allergic to nickel should avoid those alloys. DermNet NZ advises solid gold of 12 carat or more, silver or hypoallergenic stainless steel for nickel allergy. The World Gold Council's listed white gold recipes, which use palladium or silver, are nickel-free, and it says nickel-containing recipes are a small share.

That is because "white gold" is a colour, not a single recipe. If you react to nickel, ask the seller which metals are in the specific piece and have it written on the receipt. A palladium white gold is the usual nickel-free alternative. If the plating wears through, the alloy underneath touches the skin, so the alloy matters more than the plating. This is general information, not medical advice.

Both look silvery, and both can be rhodium plated: some makers plate platinum rings for extra shine and scratch resistance. The difference is what the metal is. White gold is a gold alloy, so its content is set by the karat. Platinum is a separate metal, and Canada's regulations allow the mark platinum only where 95% or more of the metallic content is platinum. The table sets the two side by side.

A higher karat means more gold and less alloy, and the mix decides the feel. 14K gold is generally harder wearing, and 18K gold has more gold and a softer feel. Palladium white gold is softer than nickel white gold, according to Corti, so ask what the ring is made from. Rhodium plating makes 14K and 18K white gold hard to tell apart by eye, so check the quality mark.

The white metal also affects your diamond. The American Gem Society says a diamond in a yellow-gold ring can look less yellowish than one in a white-metal mounting, so a white setting shows a stone's tint more plainly. If you want a bright white look in white gold or platinum, look at the diamond colour grade closely and view the stone in the setting. The gold vs platinum guide goes further.

When you plan a custom ring or band, say whether you have a nickel allergy, ask which white metal the alloy uses, and ask how re-plating works. You can note your preferences in the design studio and talk them through at a showroom. For a ring built around a diamond, the custom engagement rings service is the route, and the wedding bands collection is a place to start looking.