When you buy a gold engagement ring or watch, the metal is probably not 100% gold. Pure gold, which is 25k is gold that hasn’t been mixed with other metals.  

 

But it isn’t used in jewellery and watches for several reasons. 

 

Firstly it’s very soft, which means it would bend or warp easily. Also, pure gold scratches easily, which means that it doesn’t take long to scuff. 

 

The colour of pure gold is very bright and more orange than you would associate with gold jewellery. Because of this, it generally isn’t attractive for watches. 

 

It’s also extremely expensive. It contains twice as much gold as 14k gold. 

 

The purity content is categorised using the karat system depending on the ratio of pure gold to other alloys: 

 

 

18k gold is usually the most pure form of gold used for rings, watches and other wearable jewellery, there is very little risk of getting a skin irritation if you have a nickel allergy.