White gold has multiple sides of the white metal story on its own. It depends on two things: first, the karatage of the gold you’re considering; second, the alloy content of that particular karatage. The US standards for gold jewelry are 10k, 14k, or 18k; that is: 41.6% pure gold by weight (10k), 58.5% pure gold by weight (14k), or 75% pure gold by weight (18k). From the simple standpoint of upfront costs: the purer the gold, the bigger the price tag.
However, all gold alloys are not created equal. Mixes can vary in filler metal content and percentage, and the physical properties of each gold alloy are slightly different. Since gold is yellow by nature, it must be alloyed with white metals to act as bleaching agents. The most common recipe for many years has been silver, nickel, copper, and/or zinc. All of those metals are inexpensive and add both hardness and malleability to the finished product. In an 18k gold alloy, the 25% of filler content is usually comprised of palladium, nickel, and zinc.
With contact allergies to nickel on the rise, there are an increasing number of manufacturers using 18k white alloys that are filled entirely with either platinum or palladium. In such cases, the entire piece is made of precious metal, so they command a significantly higher price. These are also the most hypoallergenic of the white gold alloys.
For all intents and purposes, 18k white gold alloys are the most durable because they tend to be harder, yet still easier to work. 14k white is the next best option because it maintains a high durability at a more affordable price. 14k is less malleable and slightly more brittle than 18k, and so it is very slightly more likely to break than bend under force. Please note that this is a negligible difference from a quantitative perspective, but it does exist, so it bears mentioning.
All gold alloys wear away over time. Retipping of prongs and channels, and replacing or rebuilding pendant bales and clasps, and replacing the shanks of rings are an inherent part of maintaining any gold alloy.
White gold is also – technically – “whitish” or yellowish-gray as opposed to pure silvery white because gold is naturally yellow. You can’t put enough creamer in your cup of coffee to make it white, right? It’s the same concept with white gold. 14k white alloys have a higher filler percentage, so they are usually “whiter” than 18k white alloys, because the higher the karatage, the yellower it appears. It’s a unique look that isn’t unattractive by any means and is wonderful for certain kinds of designs; some people just prefer bright white.
But that coloring is why white gold is commonly plated with rhodium (a true white member of the platinum family) to give it a true white look. Periodic rhodium flashing is required to maintain white gold’s whiteness, as the rhodium plating wears off over time. But once white golds are plated, they all look the same, regardless of their karatage.
An added benefit of rhodium plating is rhodium’s outstanding wear resistance.
“But wait; what? You just said rhodium plating wears off!” It does, but rhodium plating is not simply to whiten a ring. Rhodium is between four and five times harder than the gold it’s covering. This keeps the underlying gold structure of the ring from enduring excessive wear and tear. Replacing a few microns of rhodium a year is a small price to pay for adding years of life to the actual ring.
Another potential drawback to white gold is the fillers in generic alloys. Nickel is still used extensively in white gold alloys in the United States, and an increasing number of people have or develop a contact allergy to nickel, causing irritation where the metal contacts skin.
The jewelers in my custom shop use nickel-free palladium-alloyed white gold. Palladium is much more inert and is also whiter than nickel, helping enhance the “whiteness” of a white gold alloy. Still, contact allergies to gold and even palladium do exist, although they are rarer and often much less severe than nickel contact allergies.
Now, I’m sure that seems like a lot of negativity about white gold. When white gold alloys are stacked up against platinum alloys, there’s little comparison, but white gold does have its advantages, as well.
One thing I will say for white gold is that because it is harder than platinum, and less likely to move around, it holds its finish very well. It’s also easy to play with different finishes in white gold because it’s a simple matter to add or remove them from gold.
White gold is also excellent for intricate filigree and piercework designs, where platinum’s movability works against it. In weight comparison, too, white gold can be used in chunkier pieces that would be too heavy to be practical if made in platinum.
So are white gold and platinum really comparable at all? I don’t think so, because they each have unique properties that make them better suited for different styles of jewelry. While I’ll always recommend platinum for engagement and wedding simply because of its superior durability, that does not mean white gold is not worth using. Gold has been the standard in jewelry for thousands of years for a reason.