What Is 18ct White Gold? Rhodium Plating, Palladium White Gold & Platinum Explained
18ct white gold is 75% pure gold, alloyed with 25% whiter metals. The bright, mirror-white finish most people picture is usually a thin layer of rhodium over that alloy. Underneath, the metal has a softer, warmer tone. Hereβs what that means for colour, upkeep, and how white gold compares with palladium white gold and platinum.
In This Guide
- What 18ct white gold is made from
- 9ct vs 14ct vs 18ct gold
- Why white gold needs rhodium plating
- Why white gold can look yellow over time
- Palladium white gold
- 18ct white gold vs platinum
- Is white gold right for your engagement ring?
- FAQs
What is 18ct white gold made from?
18ct white gold is real gold. The easiest way to understand it is to think of pure gold as 24 parts: 18ct gold contains 18 parts gold and 6 parts other metals. That equals 75% pure gold and 25% alloy.
The alloying metals are not simply filler. They soften goldβs yellow colour and make the finished metal more practical to wear than pure 24ct gold. White gold isnβt one universal recipe, either. Different formulations change the colour, hardness and weight of the finished piece.
Our 18ct white gold is nickel-free. Nickel is a common contact allergen, so we leave it out entirely.
9ct vs 14ct vs 18ct gold: whatβs the difference?
The carat number tells you how much pure gold is in the alloy. In Australia, purity is usually written as βctβ; internationally youβll also see βKβ. 18ct and 18K are the same.
| Gold purity | Pure gold | Alloying metals | Fineness mark |
|---|---|---|---|
| 9ct | 37.5% | 62.5% | 375 |
| 14ct | 58.5% | 41.5% | 585 |
| 18ct | 75% | 25% | 750 |
A higher number doesnβt make a piece better for every wearer. It tells you the gold content, and the larger share of alloy in lower-carat gold also changes colour and hardness. We work only in 18ct gold and platinum, so every gold piece we make contains 75% pure gold. We compare all three in more depth in 9ct vs 14ct vs 18ct Gold: Whatβs the Difference?
Why does white gold need rhodium plating?
Even after itβs alloyed, 18ct white gold usually keeps a softer cream-white or grey-white tone, depending on the formulation. The brilliant white most people recognise as βwhite goldβ comes from rhodium plating.
Rhodium is a naturally white metal from the platinum group. Itβs electroplated over the finished piece as an extremely thin layer, creating the bright, highly reflective finish associated with white gold.
Rhodium doesnβt change the gold underneath. An 18ct white gold ring remains 18ct white gold whether itβs freshly plated, partly worn or left unplated.
Why does white gold look yellow over time?
White gold doesnβt turn into yellow gold. What usually happens is that the rhodium gradually wears where the piece makes contact, letting more of the warmer alloy underneath show through.
On a ring, this often appears first on the underside of the band, along exposed edges, or where it rubs against another ring. Contact with desks, handles and gym equipment all plays a part. Itβs a normal characteristic of rhodium-plated white gold, not a sign that anything is wrong with the gold itself.
How often does white gold need replating?
Thereβs no set schedule. It depends on how often you wear the piece, where it rubs, your day-to-day routine and how you feel about the warmer tone. Some clients replate as soon as they notice it; others prefer the softer colour that develops as the rhodium wears. Replating is as much a matter of taste as maintenance. We cover timing and whatβs involved in our guide to rhodium plating and replating white gold.
Can you wear white gold without rhodium plating?
Yes. Rhodium is a surface finish, not what makes the jewellery gold. Without it, youβll see the alloyβs natural colour, anywhere from a warm cream-white to a cooler grey-white. For some designs, that softer tone is exactly the appeal. It can feel quieter and less stark than a newly plated surface.
What is palladium white gold?
Palladium white gold uses palladium, a naturally white precious metal from the platinum group, as its main whitening metal. The more palladium in the alloy, the whiter the metal. Higher-palladium formulations can be white enough that rhodium is often unnecessary, though they may still have a softer grey-white character than a freshly plated finish.
Because palladium is itself a precious metal, these alloys generally cost more to make. We explain when it does and doesnβt need plating in What Is Palladium White Gold?
What about platinum?
Platinum is naturally white, so it doesnβt rely on rhodium to stay white. Itβs also much denser than gold, so a platinum ring feels noticeably heavier than the same design in 18ct white gold. It still marks with wear, but those marks form a soft patina rather than revealing a different colour underneath.
Some clients love the weight and patina of platinum; others prefer the lighter feel and bright finish of 18ct white gold. Neither is universally the better choice. Every design in our engagement ring collection can be made in platinum. Simply select it on the product page.
18ct white gold vs platinum at a glance
| 18ct White Gold | Platinum | |
|---|---|---|
| Natural colour | Warm to grey-white, depending on alloy | Naturally white |
| Precious-metal content | 75% pure gold | High-purity platinum alloy |
| Rhodium plating | Commonly used for a bright white finish | Not needed to stay white |
| Colour upkeep | Can be replated to restore a bright finish | Can be polished if a brighter surface is preferred |
| How it wears | Rhodium gradually reveals the warmer alloy beneath | Develops surface marks and a patina |
| Weight | Lighter | Denser and heavier |
| Nickel | Not used in Carat House white gold | Not used to make platinum white |
For a closer comparison, read White Gold vs Platinum: Which Is Better for an Engagement Ring?
Can you wear platinum and 18ct gold rings together?
Yes. Having more than one metal on your hand is simply a style choice. The consideration is rings that sit directly against each other every day. As your hands move, that metal-on-metal contact causes scratches and localised wear, and different metals respond differently to the same friction.
For an engagement ring and wedding band that will rub together, we recommend matching the metals. Our wedding bands are designed to sit with your engagement ring, and we go into more detail in Can You Wear Platinum and Gold Rings Together?
Is 18ct white gold good for an engagement ring?
Yes. 18ct white gold is a long-established choice for engagement rings and wedding bands, and well suited to everyday wear. The real question is whether it suits you.
Choose 18ct white gold if you love its crisp, bright finish and are comfortable with occasional replating. Consider leaving it unplated if you prefer a softer, quieter white. Consider platinum if youβd rather have a naturally white metal that doesnβt need plating to stay white.
If youβre also weighing yellow or rose gold, Engagement Ring Metals Explained compares all four. For the ring as a whole, start with our guide to choosing an engagement ring.
Caring for white gold
White gold needs very little day-to-day care. Remove rings for the gym, gardening and manual work, and keep them away from chlorine and harsh chemicals. Clean gently with warm water, mild dishwashing liquid and a soft brush, then rinse and dry. Have a ring you wear every day checked periodically so the claws and setting stay secure. Our guide to caring for an engagement ring covers cleaning and servicing in full.
Choosing the diamond is a separate decision
Your choice of metal doesnβt determine whether your diamond is natural or lab-grown. We offer both. Natural diamonds above 0.30ct are GIA certified, lab-grown diamonds above 0.30ct are IGI certified, and every finished piece comes with an SGL jewellery certificate.
If youβre still deciding on the diamond itself:
Frequently asked questions
Is white gold real gold?
Yes. White gold is gold alloyed with other metals to change its colour and strength. 18ct white gold contains 75% pure gold.
Why is my white gold turning yellow?
The gold itself hasnβt changed. The rhodium finish has worn in high-contact areas, letting more of the naturally warmer alloy underneath show through.
Do I have to replate white gold?
No. If you like the natural colour as it appears, you can keep wearing your piece as it is. Replating is a choice, not a requirement.
Is rhodium plating permanent?
No. Itβs a surface finish that gradually wears with normal use. How quickly that shows varies from piece to piece and wearer to wearer.
Does Carat House white gold contain nickel?
No. Our 18ct white gold is completely nickel-free.
Is nickel-free white gold hypoallergenic?
It removes one of the most common jewellery allergens, but no precious-metal alloy can be guaranteed reaction-free for everyone. Individual sensitivities vary.
Is 18ct white gold suitable for everyday wear?
Yes. Itβs widely used for engagement rings and other jewellery worn daily. Like any fine jewellery, it will show signs of wear over time and benefits from occasional care and inspection.
Still deciding on a metal?
Every piece is made to order in the metal you choose, which means any design can be tailored to you. Book a consultation and weβll guide you through metal, setting and diamond together, online, wherever you are in Australia.