What is Rhodium Plating?
As beautiful as white gold jewellery is, it does require a bit of extra care to keep it looking as bright and polished as the day you bought it.
One of the key parts to white gold’s crisp, white finish is rhodium plating - a process that covers your piece in a thin, durable layer of rhodium to boost its white sheen and protect it from wear.
Though rhodium itself is a rare and precious metal, a paper-thin coating can make a world of difference in the appearance and longevity of your jewellery.
In this guide, we’ll walk through everything you need to know about rhodium plating: what it is, why it’s used, how it affects your jewellery’s appearance, and what you can do to ensure your favourite pieces always look their best.
What is rhodium?
Rhodium is a rare, naturally bright white metal that’s part of the platinum family. It’s harder than gold or silver and doesn’t tarnish, making it a great choice for jewellery plating. If this sounds too good to be true, and you’re wondering why jewellery isn’t just made out of rhodium to begin with, it’s because rhodium is incredibly expensive, and also brittle - to the point where it’s more suitable to be used as a coating, rather than a solid metal in fine jewellery.
Why is jewellery plated with rhodium?
Jewellery is plated with rhodium for a couple of different reasons, the most important being colour correction.
With white gold being an alloy of pure gold and white metals, the natural colour of it does contain a yellow hue to varying degrees, depending on the carat. To mask this tone and get a bright white finish, jewellers use rhodium plating. The result is a coating that not only looks great but also enhances the brilliance of lab-grown diamonds and other gemstones.
Besides white gold, rhodium plating is also used on silver pieces to achieve the same effect..
Platinum pieces can and do get coated with rhodium from time to time, but given that it’s naturally white, for the most part, jewellers don’t plate platinum pieces. While platinum does dull and develop a patina, having it repolished can bring back its frosty white look.
Beyond visual appeal, rhodium plating adds an extra layer of protection. Its hardness helps guard softer base metals like gold and silver from everyday wear, slowing down tarnish on silver and extending the life of the piece.
How thick is the coating?
The coating of rhodium is typically applied to be between 0.75 and 2.0 microns thick.
To apply the coating, jewellers use a process called electroplating. First, the piece is thoroughly cleaned to remove any oils or residues. It’s then submerged in a rhodium solution, and an electric current is passed through the bath. This causes rhodium ions to bond to the jewellery’s surface. This creates the bright, even layer that transforms the piece’s appearance.
The process ensures that even hard-to-reach areas are fully covered, giving white gold its signature mirror-like sheen.
Note that platings that are too thin can wear off too quickly. On the other hand, platings that are too thick can crack, given rhodium’s brittle nature.
How do I know when my piece needs to be replated?
You’ll know when your piece needs to be replated when the colour of the underlying metal starts to shine through. The time to which this begins depends on how often your piece is worn. The more wear and friction your piece receives, the faster its coating comes off.
Pieces that are worn daily that receive a lot of friction, like engagement rings, can expect to have their coatings last roughly from 12 to 18 months. Earrings and pendants, which see less friction, can have the coating stay on for several years.
Final Thoughts
Rhodium plating is a crucial step that’s often used to bring out the beauty of white gold and silver jewellery. While it doesn’t change the structure of the piece, it does make a world of difference in how it looks and how long it stays bright. Understanding this process can help you keep your cherished jewellery looking its best for years to come.
If you have a piece of jewellery that’s in need of rhodium plating, we invite you to visit us at Calgary’s Market Mall. While we do specialize in lab-grown diamond jewellery, we are also a full-service retail jewellery store that offers a myriad of repairs and services.