Silver & Gold Gold Pure gold is very yellow in colour and is exceptionally soft. It is therefore not suitable for the purposes of making jewellery in it’s purest form. Gold is mixed with other metals to create varying degree’s of hardness. 24 carat gold is 99.9% pure, 18 carat gold is 75% pure, 12 carat gold is 50% pure and 9 carat gold is 37.5% pure. Karat with a k refers to the gold content of an item of jewellery and carat with a c refers to the weight of a gemstone. Yellow gold is generally produced using gold and an alloy of copper or silver. To produce rose gold the gold is generally mixed with copper to give it’s pink (rose) appearance. There a several metals used to produce white gold alloys these include palladium, zinc and nickel.     Silver 925 sterling silver or sterling silver which is the general term for sterling silver jewellery is produced using an alloy of silver. This contains 92.5% of pure silver and 7.5% of other metals, usually copper.