Precious Metals – What’s the difference?
Let’s start with Gold, easily recognised by its rich yellow colour and familiar to everyone, but modern jewellery uses Gold in various ways, with ‘white gold’ sometimes causing some confusion. Gold is naturally Yellow and in its pure form (24ct) is very soft and considered by most not durable enough for use in jewellery, so it is mixed with other metals to form an alloy. The alloys are better known as 9ct or 18ct (14ct and 22ct and others are available). You may be familiar with the numbers 375 or 750 in the stamps and hallmarks of your jewellery, this refers to the percentages of pure gold. In 9ct gold, there is 37.5% pure gold and the rest is other metals, in 18ct gold there is 75% pure gold, the rest is other metals.
The other metals in the alloy are cleverly used to create different colours of gold such as rose or white. The traditional yellow gold used in jewellery has a balance of silver and copper and possibly other metals are used to keep a natural yellow colour. Copper is used in a higher proportion in rose gold to create the pink tones. For white gold, metals such as zinc and palladium are included which have a whitening effect, but a perfect white is very hard to create so most white gold jewellery tends to be tinged with yellow or brown or greyish hues. The brilliant white you see in jeweller’s windows is a Rhodium Plating on top of the white gold, which gives a uniform brilliant white. With time, this rhodium wears off, and you will see the base colour showing through, which can be easily restored by asking for it to be re-plated. It is also worth noting that many modern 18ct white golds are significantly whiter than 9ct because Palladium, which is an expensive precious metal is used in the alloy in greater proportions. Generally, in 9ct white gold, it is not economically viable to use high proportions of palladium.
Platinum in its alloy purity of 95% is a truly special metal, which is rare, naturally white, very durable and extremely dense which gives Platinum jewellery its unique weighty feel. It is also the most expensive of the precious metals, and rightly has the top spot as the most luxurious precious metal on the market. A Platinum piece of jewellery is an investment and will stand the test of time, needing no re-plating like white gold because its colour is naturally white.
Palladium, in its alloy purity of 95% is a precious metal which shares many of the same wonderful properties as Platinum as they are from the same family but has a lower price. Palladium is rare, naturally white, very durable but less dense than Platinum, which gives the jewellery a lighter feel. In its 950 / 95% purity, Palladium jewellery is naturally white and will stand the test of time. Compared with gold and platinum its relatively new to the market, but its properties make it a wonderful choice for wedding rings that will last a lifetime and not need re-plating. It is worth noting that recently Palladium has been marketed at a lower purity of 500, where it is 50% palladium, 50% silver. This alloy doesn’t share the same properties as 950/95% Palladium as the silver content will significantly reduce the durability, so always ask about the purity.
The best advice in choosing a metal is to go to your local jewellers and see and feel the difference between the metals. Compare the yellow colour of 9ct and 18ct, feel the weight difference between platinum and palladium and if you have any questions always ask, as an experienced jeweller will know their stock and be able to give you understandable comparisons.
Do you need to match the metals of engagement ring and wedding ring?
Matching Metals…this is always a controversial area, as many of my customers have been told that the engagement ring and wedding ring should be made of the same metal. The simple answer is ‘yes’. If they are made of the same metal, they will have the same properties such as colour, density or hardness, so the friction between the two rings will be equal and they will age and wear equally. However, to take this a little further, ALL rings worn together will cause a certain amount of friction and wear, with the softer metal wearing away faster at the expense of the harder one.
The crux of the problem is that it is very difficult to assess which is the ‘harder metal’ which is why there are so many conflicting opinions about 9ct vs 18ct. In the article “Precious Metals – what’s the difference?“ we looked at alloys, but to recap 9ct has 37.5% and 18ct has 75% pure gold, the rest is made of other metals. The alloy ‘recipe’ of these other metals is dependent on the manufacturer, the country, when it was produced, and the percentage of recycled gold, so it is always an undeterminable variable, because of the differing percentages of other metals of different harnesses.
Equally the manufacturing method will affect the density and strength of an item of jewellery, making it very difficult to assess hardness in terms of how it will react with another ring. Finally, the design and shape of the ring and how they sit against each other will affect how each ring will wear. With all these variables, you can see why everyone has a different opinion, which is not necessarily right or wrong, but merely based on their own experiences. Platinum and Palladium have different properties to Gold, but they are undeniably harder metals, and generally will be the more durable ring compared to Gold rings. This said, the same issues of manufacture, alloy and design still apply in the equation.
Another reason to choose matching metals, is colour. Generally 9ct yellow gold is slightly paler than 18ct yellow gold, although some manufacturers are producing modern alloys with a more uniform colour in line with demands from consumers. White Gold is an alloy of pure (yellow) gold, where the metals used to create the alloy has a whitening effect. Often the alloy, especially 9ct will still show a yellow tinge, so as an industry standard the majority of white gold jewellery is Rhodium Plated. As the Rhodium wears off over time, you may find that the base colour of the white gold showing through doesn’t match well with the engagement/wedding band/eternity ring, in a pairing of 9ct/18ct or white gold and platinum/palladium.
Bearing this in mind, some couples may decide that although the engagement ring is 18ct gold, they only have the budget for a 9ct wedding band. If this is the case, it’s not the end of the world – frictional wearing is something that happens over decades not years and simply check that you are happy with the difference in colours between the metals. Be aware that ‘white’ gold tends to have a better white colour in 18ct than 9ct. With this information and the countless anecdotal stories, anyone who gives a definite ‘yes’ to “should the engagement ring and wedding ring should be made of the same metal?” is wrong, but a ‘yes, it is probably advisable’ is more appropriate.