Gold is a soft, dense, bright yellow metal used in watches for cases, bracelets, dials and hands. On its own it is too soft for daily wear, so watchmakers use gold alloys. The usual standard is 18 karat, which is seen as a good compromise between purity and toughness.
What do 18k and 14k mean?
Karat tells you how much gold an alloy contains. Gold that is essentially pure, at 99.9% or better, counts as 24 karat. 18-karat gold is 75% gold, and 14-karat gold is 58.3%. Other metals make up the rest. Pure gold bends and stretches easily and lacks the strength for much practical use, so 24-karat gold is too soft to wear every day. Mixing in other metals makes it tougher, but also less pure. This is why any coloured gold is less pure than 24 karat.
How does gold get its colour?
Yellow gold gets its rich colour from a balanced mix of silver and copper added to the gold. Changing the proportions of those two metals can produce white, yellow, green or red golds. Red, rose and pink golds differ from one another mainly in how much copper they contain. White gold is different again. It is alloyed with at least one white metal, such as nickel, silver, platinum or palladium. In Europe, shades of gold are graded on a standard scale that usually runs from 1N to 5N.
Where is gold used in a watch?
Gold is used for cases and bracelets. It is also used for outer parts such as dials and hands. It appears inside the watch too. Automatic movements often have rotors, the oscillating weights, made from a 22-karat gold alloy. Some makers produce their own gold. Omega’s Moonshine Gold is an 18-karat yellow gold made from 75% gold, 14% silver, 9% copper and 1% palladium.
Where it comes from
People have worked gold for a very long time. The world’s oldest known gold objects were found in Bulgaria. They date to the 5th millennium BC. No older gold objects are known anywhere in the world. The English word ‘gold’ comes down from Proto-Germanic. It has relatives in many other Germanic languages.
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