All That Glitters

These proprietary gold blends may all have 18K purity but their wildly varying properties illustrate metallurgy’s importance to contemporary watchmaking.

- Jamie Tan

There isn’t any status symbol that’s quite as ubiquitous as gold, and its universal appeal is easy to understand. The metal’s rarity is reason for its value, while its physical properties explain its allure – gold’s density gives it heft, which implies weight and importance, while its inert nature is often associated with ideals of being constant and unchanging. That final property also means humans won’t be allergic to it, unlike silver, for example.

Still, gold isn’t without its limitations, chief among which is its softness that precludes pure gold from use in both jewellery and timepieces. By mixing gold with other metals to create alloys, however, hardness and other desirable properties can be attained. Yet this isn’t without cost – literally. Alloys have lower gold content and thus less value, making them less precious – unless the other metals in the mix are even more precious, like platinum. The question, then, is the purity of gold to be used in the context of watchmaking.

The watchmaking industry has settled on 18K (where gold accounts for 75 per cent of an alloy’s mass) as the de facto fineness for gold alloys used in timepieces. This standard is a good balance between maintaining the value of the alloy (due to its gold content), and the hardness and colours that can be achieved. Three main shades of gold are used in watches. Yellow gold is the most traditional, and retains the colour of pure gold. White gold contains nickel, palladium, or another white metal, and is usually rhodium plated for a brilliant shine. Rose gold, on the other hand, skews towards red thanks to the inclusion of copper.