“Behind The Gems” is a long-running monthly series that takes you on an exclusive, behind-the-scenes tour of our signature collections.
Knowing your metals means knowing what you buy, which in turn, leads to having pieces that not only look splendid, but also last a lifetime. So read through this edition on white gold to ensure that you make informed purchase decisions each and every time!
General Notes About Gold
We’ll start with some quick facts about gold in general.
Fact #1: Gold used in jewellery is always a compound, as pure gold is far too soft and scratches too easily.
Fact #2: Gold purity is measured in carats (spelled karats in the US), with 24ct being completely pure gold. In practice, however, 22ct is the highest usable purity, followed by 18ct, 14ct and 9ct.
Fact #3: Here at McFarlane Fine Jewellery, we work with 18ct because it has the best balance between purity and durability.
What Is Special About White Gold
White gold is a gold alloy. It is made up of pure yellow gold and a second "silver" metal like palladium, manganese, nickel or silver. Out of these, we like to work with palladium, as nickel can often cause allergies.
White gold has the same appearance as platinum, but at a more affordable price point. And, compared to silver, it is more durable and holds its value in the long run – just like its rose and yellow gold counterparts.
Rhodium Coating And Re-Coating
White gold is frequently coated with rhodium for added strength and to give it a bright white finish (it naturally has a slightly yellow tinge due to the yellow gold). Rhodium is the perfect precious metal for this because it is harder than gold and hypoallergenic.
The thickness of the coating tends to stay between 0.75 and 1.0 microns. Any thicker and the coating could crack, any thinner and the surface could look discoloured or uneven. The coating itself will wear off over time depending on the pH level of your skin, how often you use the jewellery and how often it comes in contact with household chemicals.
For this reason, white gold jewellery needs to be re-coated every few years. We offer this as a free service on all our pieces – email us!
Jeweller’s Note: Given that rhodium is 10 to 25 times more expensive than gold, you may be wondering: why not use rhodium itself to make rings, necklaces and earrings? Well, the answer is simple: rhodium is too brittle for extensive use in jewellery.
White Gold Jewellery Care
There are several things you can do in order to make the rhodium plating last longer and extend the time between re-platings. Here are our recommendations:
1. Keep it away from rough surfaces and harsh chemicals.
2. Take your rings off when you wash your hands, as contact with soap and water will gradually cause wear.
3. Take your rings off when swimming in the ocean or in pools, as sand and chlorine will increase the rate of wear and tear.
4. Also take your rings off if you plan on gardening, cooking, working with your hands etc.
5. When travelling or when they’re not in use, keep all your jewellery pieces stored in separate pouches or jewellery cases.