White gold does not rust, as rust is the specific deterioration process (iron oxide) that affects iron and steel when exposed to oxygen and water. White gold, an alloy of gold and other metals, is chemically resistant to this type of corrosion. However, the common question about “rust” points to the real issue: white gold changes color over time due to plating wear and minor tarnishing of its non-gold components. This gradual shift from bright white to a duller, yellowish tone is normal.
The Difference Between Rust and Tarnish
Rust is the common term for the deep, structural corrosion of ferrous metals (those containing iron). This reaction requires oxygen and moisture to form iron oxide. Gold is a noble metal, meaning it is chemically inert and does not react with oxygen to form rust.
Tarnish is a different type of surface discoloration affecting metals like silver, copper, and the non-gold metals in alloys. Tarnish is typically a thin, dark film, often a metal sulfide, that forms when the metal reacts with sulfur compounds or oxygen. Unlike rust, tarnish is self-limiting, affecting only the outermost layers without causing structural damage. White gold’s color change relates to the subtle chemical processes of its non-gold ingredients.
Understanding White Gold’s Ingredients
White gold is not found in nature; it is a manufactured alloy created by mixing pure yellow gold with one or more white metals. To achieve a paler hue and increase durability, gold is typically alloyed with metals such as nickel, palladium, or sometimes copper, silver, and zinc. The karat weight, such as 14K or 18K, indicates the percentage of pure gold in the mixture, with 14K gold containing 58.3% pure gold.
Despite the addition of whitening metals, the underlying alloy still retains a slight yellow or grayish tint from the natural color of gold. To achieve the brilliant, reflective, and true white finish seen in jewelry stores, almost all commercial white gold is electroplated. This plating uses rhodium, a rare and highly durable member of the platinum-group metals. The rhodium coating is microscopically thin, providing the final, bright-white surface and intense luster consumers expect.
Why White Gold Changes Color Over Time
The primary reason white gold appears to change color is the inevitable wearing away of the rhodium plating. This ultra-thin layer, which is typically less than one micron thick, is subject to constant friction and abrasion from daily wear. Areas of high contact, such as the bottom of a ring band or the tips of prongs, will show wear fastest.
Once the rhodium layer is gone, the natural, slightly warmer color of the underlying white gold alloy is exposed. This often manifests as a patchy, pale yellow or champagne-colored hue on the surface. Chemicals commonly encountered in daily life, such as chlorine (found in pools and cleaning products), bleach, and even the natural oils and sweat from the skin, accelerate the deterioration of the rhodium layer.
A secondary factor is that non-gold metals within the alloy, such as copper or silver, can slightly oxidize or tarnish once the rhodium barrier is breached. This localized reaction with environmental elements or skin chemistry causes subtle dullness or darkening. The combined effect of the yellow undertone showing through and minor alloy tarnishing creates the illusion that the white gold is “fading.”
Keeping White Gold Looking New
Maintaining the bright appearance of white gold centers on preserving the rhodium plating. A practical step is to remove the jewelry when engaging in activities that involve harsh chemicals, such as cleaning with bleach or swimming in chlorinated water. These substances chemically erode the rhodium coating, causing it to wear away faster.
Gentle cleaning with mild soap and warm water is sufficient for removing oils and surface dirt without damaging the plating. The most effective way to restore the original white color is through periodic professional maintenance. Jewelers can re-apply a fresh layer of rhodium through electroplating, which typically needs to be done every one to three years, depending on wear frequency. This simple re-plating restores the metal to its as-new appearance.