You might know that it takes a musician to sell 500,000 albums for it to be designated as a gold record and 1 million albums for a platinum record, but did you know that in 1979, the Guinness Book of World Records awarded the first rhodium disc to Paul McCartney for being the best-selling musician at the time.
As the most expensive precious metal, rhodium often is used to honor or award elite status; some of the most expensive decorative items in the world are made from rhodium. Many types of jewelry are rhodium-plated; in particular, you’ll often find rhodium-plated white gold, rhodium-plated platinum, and rhodium-plated silver.
But what is rhodium plating, and what purpose is rhodium used for in jewelry? Let’s get into the properties of rhodium, its benefits, and care.
What is Rhodium?
Rhodium is a highly reflective, silvery-white pure precious metal in the platinum family that is corrosion-resistant. It’s a very hard metal—much harder than other pure metals such as platinum, gold, and silver.
Rhodium is also one of the rarest of all metals and is, therefore, the most expensive precious metal. It can be up to 10–25 times more expensive than gold. Rhodium’s price per ounce is currently $16,650.00, although it fluctuates.
Being a noble metal, pure rhodium is chemically inert; it’s safe and resistant to some of the chemical reactions that impure metals are affected by.
Here are some of rhodium’s benefits:
- Hard and durable
- Resistant to scratches and dents
- Shiny surface, highly reflective sheen
- Non-porous, even in thin layers
Rhodium’s appearance is similar to chrome, and its hardness is like iron. Rhodium is known for its luster—it reflects about 75-80% of incidental light. The only way to dissolve rhodium is with sulfuric acid.
What Is Rhodium Used For?
Like pure gold, rhodium has many uses in science, industry, and medical technology. It’s used in catalytic converters, aircraft spark plugs, optical instruments, medical-grade filters, and more.
If you’re wondering about the history of rhodium plating, the process of rhodium plating became a common trend in the early 1930s. The most common pieces that were rhodium-coated were luxury pens, Art Deco-style cigarette lighters, and cutlery. As early as 1932, wealthy people would order custom rhodium-plated silverware sets.
In jewelry and fine decorations, rhodium is used as a plating to provide a bright luster to the surface of the item, as well as protection.
Where is Rhodium Found?
Rhodium occurs in nature in North and South American river sands in an isolated form. Rhodium is also found in Ontario, Canada, in copper/nickel sulfide ores. You can also obtain rhodium as a commercial by-product of copper and nickel refining processes.
What is Rhodium-Plated?
Rhodium-plated means that the jewelry’s base metal of gold, silver, platinum, or other metals, has been coated in a thin layer of rhodium (via electroplating) for increased durability and shine.
- Rhodium-plated white gold: White gold still contains a yellow tint from its pure gold, so a rhodium plating gives it a shinier, platinum-like appearance, which enhances the brilliance of diamonds and gemstones. Also, gold is much softer than rhodium, so rhodium-plating can make gold more scratch-resistant.
- Rhodium-plated sterling silver: Sterling silver contains 92.5% pure silver. Due to the other metals in its alloy, it tarnishes over time. A rhodium-plating increases the durability of sterling silver jewelry and makes it tarnish-proof.
- Rhodium-plated platinum: Rhodium plating gives platinum jewelry a shinier finish. Keeping platinum rhodium-plated can increase its durability and prevent it from developing a patina.
- Rhodium-plated brass: Brass is a cheap metal used in costume jewelry. It can turn your fingers green if exposed to water or oils on your skin. A rhodium plating prevents brass from reacting. That said, avoid rhodium-plated brass jewelry, since it will only be plated in a thin layer of rhodium that will wear off fast. You’d have to re-plate brass in rhodium every few months, spending more money than it’s worth.
Being a pure metal, rhodium is hypoallergenic, so wearing rhodium-plated 14K white gold earrings is safe for sensitive ears.
However, solid rhodium is very rare, and you can’t really make jewelry out of pure rhodium. Rhodium’s hardness makes it too brittle to shape into different forms, as opposed to silver, gold, and platinum, which are more malleable.
How Long Does Rhodium Plating Last?
After a while, rhodium plating will wear off due to regular wear. When it comes to how often should you re-plate rhodium-plated jewelry, it depends on the jewelry item.
A plated rhodium ring may need to be re-plated once every 1 year to 18 months, but this can vary depending on the wearing factors, as well as how thick the rhodium plating is. The color of the base metal can also play a role in how often you need to re-plate white gold in rhodium.
An individual’s body chemistry can factor into how soon the rhodium plating wears off. If the base metal is yellowish (such as 18K white gold), the yellow tint may bleed through sooner than 1 year of wearing, indicating it’s time to re-plate your jewelry.
Buying rhodium-plated gold, silver, and platinum reduces the need for you to constantly clean and polish your jewelry. However, you will need to get your white gold engagement ring or other jewelry re-plated in rhodium every year or so.
That said, there are some steps you can take to make rhodium plating last longer.
- Avoid rubbing your rhodium jewelry/polishing it too hard.
- Take your jewelry off when swimming in pools or at the beach.
- Avoid exposing your jewelry to harsh chemicals.
- Take your jewelry off before cleaning (or wear rubber gloves).
- Avoid getting perfume on your jewelry.
- Rinse your jewelry in water and wipe off residue if you get sweat or other chemicals on it.
Rhodium will require periodic polishing, but not as often as yellow gold or sterling silver would. When it comes to how to clean rhodium-plated jewelry, make sure to do so gently—only use a children’s soft-bristled toothbrush or other soft brush to dislodge dirt.
Pro tip: Only clean precious metal jewelry with soap as needed. For regular maintenance, soaking it in water, gently brushing it, soaking it again, and drying it should often suffice.
Is Rhodium Plating Worth It?
While rhodium-plated jewelry does require re-plating, it’s more affordable than platinum jewelry. Furthermore, it’s hypoallergenic—if you have metal allergies, you can opt for even a 14K white gold rhodium ring as hypoallergenic jewelry, without having to buy a higher purity gold ring, such as 22K gold, which is softer, more expensive, and requires more cleaning.
Here at Karini Jewelry, we offer both 14K and 18K white gold rhodium-plated rings, necklaces, earrings, and more. Check out our white gold vintage rings, unique engagement rings, fashion rings, and more for distinctive designs and free personalized engravings.