White Gold Metals
Also: Whitening agents, Bleaching metals (gold)
White gold metals are the precious metals that give gold a silvery-white colour when used as alloying partners – primarily palladium, platinum and nickel.
White gold metals are alloying partners that give the precious metal gold its characteristic silvery-white colour. Since pure gold (fine gold 999) is naturally a rich yellow, metals are deliberately alloyed into it to visually neutralise or completely mask this yellow tint. Depending on the choice of whitening agent, alloys with very different properties are produced – both technically and in terms of compatibility and price.
The Most Important White Gold Metals at a Glance
| Metal | Effect | Typical content | Special feature |
|---|---|---|---|
| Palladium | strongly whitening | 5–15 % | hypoallergenic, valuable |
| Platinum | whitening | up to 10 % | very hard, expensive |
| Nickel | strongly whitening | 8–20 % | inexpensive, but allergy-causing |
| Silver | brightening | 10–25 % | slight residual yellow tint |
Palladium is today considered the preferred whitening agent for high-quality jewellery alloys. It is a platinum-group metal, hypoallergenic, and gives 750-fineness white gold (18 karat) a natural whiteness without rhodium plating being strictly necessary. Pd white gold typically contains 5–15 % palladium alongside other alloying metals such as silver or copper.
Platinum as a whitening agent also produces a very bright, allergen-free alloy, but is less commonly used due to its high price. More often, platinum is used as an independent jewellery metal in high-purity alloys (950 Pt).
Nickel was the most widely used whitening agent until the 1990s. Since the EU Nickel Directive (Directive 94/27/EC, subsequently incorporated into REACH), nickel content in jewellery has been strictly limited because nickel frequently causes contact allergies. Older white gold therefore often still contains nickel – recognisable by a stronger yellow tint after the rhodium plating wears off.
Rhodium Plating as Surface Protection
Most white gold jewellery pieces receive a final rhodium plating – a galvanically applied layer of rhodium (0.1–0.5 µm). Rhodium is a platinum-group metal, extremely hard and corrosion-resistant, and significantly enhances the white appearance. After years of wear, the layer wears through and reveals the slight yellow tint of the base alloy; a refresh at the jeweller's is then customary.
Price and Market Significance
The palladium price and platinum price directly influence the cost of white gold alloys. Rising palladium prices – as seen between 2016 and 2022 – can prompt manufacturers to switch to nickel or higher silver proportions. The melt value of a white gold piece therefore does not depend solely on the gold content, but on the entire alloy composition.
Note: Statements on the tax treatment or return prospects of white gold alloys do not constitute tax or investment advice.
In Brief
White gold is created by the deliberate addition of palladium, platinum or nickel to fine gold; the choice of whitening agent determines the colour, compatibility and price of the alloy. A final rhodium plating provides the distinctive high-gloss finish and protects the surface.