The Story Behind the Stone: Rich and Rare – Rhodium

Fans of white gold jewelry actually love the rhodium plating on their piece. This is what they are looking at with a new white gold item. White gold jewelry is routinely plated with rhodium after its manufacture to ratchet up that glistening icy appearance. It was originally created to mimic platinum that came into popularity at the dawn of the 20th century. White gold is yellow gold mixed with alloys like nickel, palladium, or silver, which eventually begins to show the yellow base through the alloyed metal. The alloys used in making white gold turn the metal white, but also act to strengthen it. That’s a good thing since 24K gold is quite soft.

Another important benefit of rhodium plating is creating longevity for the item by providing resistance against everyday scratches and scrapes. It’s important to note that this shimmering white metal is also hypoallergenic, so it’s unlikely to aggravate an allergic prone wearer’s skin. Every jeweler knows this is a big deal for customers who have difficulty finding jewelry that won’t leave them with a red, itchy rash. Rhodium is highly resistant to corrosion unlike some of the alloys used in white gold. Pure gold (24K as found in the earth) doesn’t tarnish since it can’t combine easily with oxygen which promotes tarnish on metal.

Take a Dip

The rhodium plating process involves applying a thin layer of rhodium onto the piece of jewelry which makes the metal look significantly whiter and adds an attractive, reflective white finish. While this technique is routinely applied to white gold jewelry, it can also be applied to sterling silver and other precious metals.

Jewelry owners should consider re-plating their white gold jewelry with rhodium every few years – sooner if the piece is subjected to heavy daily use. Consumers might request an extra thick layer of rhodium for well-worn white gold pieces which are expected to continue having heavy wear.

What is Rhodium Anyway?

We rarely hear anything about this metal outside of its use as a plating material for white gold jewelry. Rhodium belongs to the platinum family and is considered not only precious, but rare to boot. Unlike gold and silver which were prized metals used since antiquity, rhodium is the new kid on the block.

English chemist William Hyde Wollaston discovered it in 1803 shortly after he identified the element palladium. Wollaston extracted rhodium from a chunk of platinum ore he acquired from South America. Rhodium often occurs where deposits of platinum are found, and with today’s mining, it is commonly separated through the refining process of platinum.

It sells for a much higher price per ounce than other precious metals like platinum and gold. In Q1 of 2021, rhodium’s price per ounce skyrocketed to $28,775 before tapering downward toward the end of 2022. Ever changing market conditions cause this and other precious metals to fluctuate widely. But rhodium’s rarity, limited availability and complex extracting procedures adds to its ongoing steep prices.

What Else is Rhodium Used For?

There’s a whole world of uses for rhodium outside of the jewelry industry. For instance, rhodium is instrumental in building catalytic converters used to clean vehicle emissions. Without these rhodium catalysts, our cities air quality would suffer greatly due to worsening vehicle exhaust.

Rhodium is alloyed with platinum for use in aircraft turbine engines. We also find rhodium used for coating optic fibers, crucibles, thermocouple elements and even with headlight reflectors. When it’s alloyed with platinum and iridium, the result is an oxidation-resistant metal able to withstand super high temperatures. The application of these alloys is found in furnace windings, pen nibs, high-temperature thermocouple and resistance wires, bearings, electrical contacts, and more.

Where to Find

In nature, rhodium can be discovered as a single element or together with other platinum minerals. Rhodium turns up in river sands of North and South America, and in copper-nickel sulfide ores in Ontario, Canada. For large scale supplies, look to South Africa which supplies roughly 80% of the world’s rhodium production.

When discussing rhodium plating with your customers who might waffle at the extra cost of re-plating, it’s not a bad idea to bring up the interesting history and rarity of this metal. All in all, it’s an economic means of preserving the strength, luster, and beauty of their jewelry for a lifetime.