Ever since human beings learned the art of metalworking, they have been fascinated by the timeless beauty of gold. They crafted not only ritual artefacts and jewellery in gold but also used it to fashion particularly precious secular objects.
But in its pure, natural form, gold is relatively soft. So for jewellery and watches, gold is alloyed with traces of other metals to make it harder. But even then, its surface is fairly sensitive. People who wear precious pieces on their wrists must be careful to protect them from scratching.
For this reason, an innovative gold alloy was developed for the anniversary “Homage to F. A. Lange” edition: 18-carat honey-coloured gold. Its subtly warm honey hue can easily distract from its other principal property: with a Vickers hardness of 300 to 320HV1, it is significantly harder than conventional gold alloys, so it is much more resistant to the signs of the times.
A case in point: ordinary yellow gold has a Vickers hardness of 135HV1. That is equivalent to a value of 3 to 4 on the more familiar Mohs scale. The Mohs method determines the hardness on the basis of which materials can scratch the medium being analysed. Conventional yellow gold belongs to the class of materials that can be readily scratched with a copper coin. 18-carat honey-coloured gold has a Mohs hardness of 4 to 5, and it would already take a knife made of decent steel to scratch it.
A NEW GOLD ALLOY MARKS THE 165TH ANNIVERSARY.
