The Scottish Heirloom Company, like most jewellery manufacturers, produces our product range in Sterling Silver, 10 kt (karat), 14kt and 18kt gold. When choosing items in gold, customers are often reluctant to choose higher karats of gold. This is not due to higher prices, but they have heard that 18 kt gold is softer and will wear away faster than 10kt. Is this correct? - The answer is a definite "NO!".
This is usually a surprise to many customers and also to, strangely enough, many jewellery stores sales staff..
This incorrect belief is kind of understandable, as it is fairly well known that pure (24 kt) gold is too soft to be used in most jewellery and has to be alloyed with other metals to make it harder and more durable. It is then believed that more of other metals that are added to gold, harder it becomes. The sales staffs in some jewellery stores, that mainly sell cheaper 10 kt gold items, also sometime state this idea in order to help sell 10 kt items.
Here are approximate maximum "Vickers" hardness values of various Karats of gold. The higher number, harder alloy.
10 kt ............ 170 14 kt ............ 180 18 kt ............ 230 Sterling silver .. 65.
As you can see, contrary to most people's expectations, 18 kt gold is hardest of alloys.
The term 'Karat', also spelled 'Carat' comes from Greek word for seed of Carob tree. These seeds are very uniform in weight and were once used as standard weights when measuring very fine items. The term Karat or Carat is now also used as a measure of purity of gold, as a number of parts of gold by weight in every 24 parts of a Gold alloy. The other metals included in most gold alloys are usually copper, silver and zinc.