As jewellery designers we are often asked to clarify the difference between gold – specifically white gold and platinum. While these two metals may have an almost indistinguishable appearance, their properties and characteristics are quite unique.
So what are these differences?
Well if you want to get all technical about it, Platinum (Pt, atomic number 79) has a density of 21.45g/cm3. In the jewellery industry platinum is most often alloyed to 95% fine (pure) platinum and 5% other metals such as ruthenium to make it more workable.
Gold (Au, atomic number 79) in its fine form (24ct), has a density of 19.32g/cm3. Being a rich yellow metal, fine gold must be alloyed down to achieve white gold. In the South African jewellery industry the most common alloys of white gold are 18ct, which is 75% gold, and 9ct, which is 37.5% gold. The other metals used to achieve workable white gold are commonly silver, and in our case palladium as this ensures a very high standard of colour and durability.
So if these two metals look the same, why do we offer you both?
Truth is, both metals have their advantages and drawbacks, and the preferable one often depends on what you perceive to be best for your engagement ring.
Why platinum?
Platinum is a high quality, high purity metal that is well known for its exceptional prestige and durability, especially when it comes to designs with fine claws and wire detail. There are some setting styles we would always recommend platinum for, as gold lacks the hardness or tensile strength to ensure the security of the diamond. However, platinum is also very dense and therefore very heavy. A very chunky engagement ring, for example, that is made in platinum would be uncomfortably heavy for some people to wear, while the same ring in 18ct white gold would not pose a challenge.
Thanks to the difference in density, an engagement ring made according to the exact same dimensions, would weigh approximately 43% more in platinum than it would in 18ct white gold and about 90% more than in would in 9ct white gold. This being said, a very dainty ring made in platinum would keep its shape better than it would in either variety of white gold.
Why white gold?
Besides being a more comfortable weight in some ring designs, gold is more affordable than platinum due to three reasons. Firstly, the gold we use has a lower price per gram despite what the international gold and platinum standards may be. This is due to the lower metal purity of 18ct or 9ct gold compared to platinum. Secondly you need fewer grams thanks to the density difference (remember) and thirdly, gold is much easier to manufacture in, keeping the labour costs down.
Clients often don’t realise this, but 18ct and 9ct white gold in its raw form has a greyish glow – slightly darker than platinum. To get the lovely white colour this metal is famous for, the completed piece of jewellery gets plated with a thin layer of rhodium (an exceptionally white relative of platinum). Although rhodium plating, when properly applied, is quite durable, it does wear away with time, leaving the natural grey of the white gold exposed.
While a white gold engagement ring does need its rhodium plating re-done every 12 to 24 months, depending on how hard it is worn, this metal has gained an unfair reputation of being high maintenance. Both platinum and white gold (18ct and 9ct) will get light scratches with wear, so both metals need to be re-polished by a reputable jeweller every so often. This presents the ideal opportunity to have the health and security of all diamonds and settings checked, which is advisable anyway. The only difference in general upkeep is that white gold will need to be re-plated once polished, but as this is a relatively affordable process, there is no reason to dread maintaining a gorgeous white gold ring.
At Mark Solomon Jewellers we offer the highest commitment to quality and workmanship, as well as the most competitive diamond prices South Africa has to offer. Contact us about discussing your custom made diamond engagement ring today.
