22 carat gold contains 91.67% pure gold so it is known as 916 gold. Because of the metal composition, the remaining portion is made up of other mixed metals to increase durability. In both the ...

This means that if you buy 18K gold, 18 of the 24 parts will be pure gold and the rest will be a 50:50 mix of copper and silver because the purest gold is too soft to be used in jewellery.