The crafting of an engagement ring starts with a precious metal. Whether yellow gold, rose gold, white gold or platinum, each metal has its unique qualities, advantages, and disadvantages.
Colour, shine, purity, strength, price, and rarity differ between each kind of precious metal and each type also comes in many forms. For example, gold isn’t just gold: it could be anything from 18k white gold, 14k rose gold, 18k yellow gold, and more.
To assist you on your engagement ring journey, we have created this helpful guide to make exploring precious metals a little easier.
The Most Popular Precious Metals for Fine Jewellery
According to the International Gem Society , gold, silver, and platinum are the most popular precious metals used in fine jewellery.
Platinum
Platinum is a sleek, silvery-white precious metal with an unmistakable shine. Platinum’s natural strength is enhanced by adding a small percentage of another metal before it is crafted into jewellery. Jewellers may choose a range of metals to add to the alloy to strengthen it. At Cullen Jewellery, we use cobalt. Like platinum, cobalt is naturally hypoallergenic, making platinum rings a great option for people with metal allergies. Platinum is extremely durable and will not tarnish or corrode. Platinum jewellery comes at a higher price than gold jewellery due to its relative rarity, density, and strength.
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18k Yellow Gold
18k yellow gold is the preferred choice for most premium jewellers, thanks to its traditional warm hue, lustre, and high gold content. While 18k and 14k gold have similar hardness levels on the Vickers scale—offering comparable resistance to scratching—18k gold stands out for its durability. It’s less prone to breakage, more corrosion-resistant. It has a higher elongation percentage, meaning it’s more likely to bend rather than break—a vital feature for securely holding gemstones like diamonds in place.
Another advantage? 18k yellow gold is more hypoallergenic than 14k, making it an excellent choice for those with metal sensitivities.
18k Rose Gold
18k rose gold is an alloy consisting of gold and copper, resulting in a blush pink colour. Rose gold is particularly flattering on warmer skin tones and comes at a similar cost to yellow gold. With added strength provided by the copper in the alloy, 18k rose gold is a long-lasting precious metal that will not require maintenance to keep its distinctive colour.
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18k White Gold
With a silvery-white appearance similar to platinum, 18k white gold is a stunning and more affordable option for those who prefer cool-toned jewellery. Unlike platinum, which develops a patina finish that enhances its durability and appeal, white gold is plated with rhodium to create a shiny white finish. White gold requires more maintenance than platinum, as the rhodium plating wears off over time, revealing the gold alloy's original colour beneath.
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Two-Tone
Two-tone rings often feature a lighter-coloured precious metal such as platinum or white gold at the top (also called the setting of the ring), creating a striking and versatile visual contrast that can pair well with jewellery of different metal types.
A two-tone design combines two different metal colours, creating a unique and versatile piece of jewellery that can be customised to complement all skin tones.
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The Differences Between 9k, 14k, and 18k Gold
Many precious metals, like gold, are naturally soft, which means that before they can be made into fine jewellery intended for everyday wear, they must be mixed with other metals to add strength.
The purity of a gold alloy is expressed in karats (k), with gold weight measured as parts out of 24.
24-karat gold is pure, solid gold, whereas 9-karat gold (where nine parts out of 24 are pure gold) is generally the lowest amount of gold an alloy needs to contain to be still considered gold.
Being pure gold, 24k gold possesses the richest gold colour, but it’s also very soft and malleable, making it impractical for everyday wear.
Did you know?
A gold ring will usually have a three-digit number stamped on the inside of the band, indicating the purity of the gold alloy. The number 375 indicates 9k gold — as nine parts out of 24, expressed as a percentage, is 37.5%. 18k gold will have a 750 stamp to represent its 75% purity, and 14k gold will be marked with the number 585 to indicate 58.5% pure gold.
Why Choose 18k over 14k Gold?
18k and 14k are more commonly used in gold jewellery. They are similar in price but differ in durability and lustre.
18k gold is the alloy of choice used by most high-end jewellers. The strength and price point of 18k gold alloys are comparable to 14k gold, but 18k gold jewellery tends to last much longer. There are several technical reasons why this is known to be the case in the jewellery-making community. For one, 18k gold has a higher elongation percentage than 14k gold, which means it is more likely to bend than break when pressure is applied. For a gold ring or pendant, this is important, as if any of the claws in your stone’s setting were to snap, you could lose the stone. This is why 18k gold tends to be preferred in engagement rings.
14k gold is also more likely to corrode than 18k gold due to its microporosity, making it less ideal for long-lasting wear.
Last but not least, 18k gold also possesses that buttery appearance that has captivated gold lovers for centuries.
How to Navigate Metal Allergies
Finding the right precious metal for an engagement ring isn’t just about how it looks, but also how comfortable it is to wear. Rose gold, white gold, and yellow gold all have metal alloy properties that affect metal allergies differently.
Hypoallergenic Precious Metals
Unfortunately, rose gold is an alloy with a high proportion of copper. Copper gives rose gold its pinkish hue, but copper can also cause a reaction if you have a metal allergy.
If you have a metal allergy, it is best to choose platinum or a gold alloy that is as close to pure gold as possible, such as 18k yellow gold. Being closer to pure gold, 18k gold has a low percentage of other metals in the alloy, making it safer to wear.
Can All Ring Metals Be Resized?
Not all rings can be resized. Eternity bands and designs with intricate settings can be more challenging—even impossible—to adjust. Furthermore, some precious metals are more difficult and require more skill to resize without visible soldering lines.
Resizing Yellow Gold Rings
Thanks to its malleability, yellow gold is one of the easiest metals to resize. However, the process also depends on the skill of the jeweller and the quality of the band. In most cases, resizing a yellow gold ring is possible.
Resizing Rose Gold Rings
Rose gold solder is relatively new in the jewellery industry, which means awareness is very low. Many traditional jewellers won’t offer it as an option for your resize. At Cullen Jewellery we have access to rose gold solder. When you have a rose gold ring resized with us, the precious metal used in the ring and solder will be matched in strength and colour. Other jewellers might use a lower-carat solder, with less than perfect outcomes.
Resizing White Gold Rings
While white gold rings are plated with rhodium and can be resized, the process requires the ring to be replated afterwards. This step may add to the cost since rhodium is a rare and precious material.
Resizing Platinum Rings
Platinum solder is also less common due to its high cost and melting point, making it challenging to work with. Platinum has a higher melting point than gold, which means that heating platinum enough to make it into a liquid solder would also burn the stones.
If the metal in the solder isn’t a match for the metal in the ring, you will be able to see a join in a different colour where the resize has taken place. However, at Cullen Jewellery we use a new, specialised laser machine that can solder precisely with platinum while keeping the stones intact.
Fine Jewellery Crafted with Love
Cullen Jewellery was founded in 2018 to celebrate life's cherished moments, conscientiously. Headquartered in Melbourne, Australia, Cullen Jewellery specialises in carbon neutral lab grown diamond and moissanite engagement rings.
Book your Cullen Jewellery consultation and be welcomed into a world of fine jewellery that is accessible and enduring.