Hardness of Gold, - misconceptions!
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 the higher karats of gold. This is not due to the 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
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 the more of
the other metals that are added to the gold, the 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 the 10 kt items.
Here are the approximate maximum "Vickers" hardness values of
the various Karats of gold. The higher the number, the harder
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 the hardest of the alloys.
The term 'Karat', also spelled 'Carat' comes from the Greek word
for the seed of the 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 the purity of gold, as a number of the 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
24 kt is pure gold, with no other metals. 18 kt is 18 parts gold
and 6 parts total of silver and copper. (75.0% gold) 14 kt is 14
parts gold and 10 parts total of silver and copper. (58.3%) 10
kt is 10 parts weight of gold to 14 parts of other metals.
Because Gold is so much heavier than the other metals, the
actual amount of gold, by volume, in the different alloys is
10 kt = 41% by weight and 24% by volume. 14 kt = 58.55 by weight
and 39% by volume. 18 kt = 75% by weight and 61% by volume.
Which is best?
We always produce items, which are designed to be Heirlooms and
as such are made to last for many generations. Whether it is 10,
14 or 18 kt, it is certainly not going to wear out. My favourite
is, however, 18 kt gold. It is the hardest wearing, looks good
and is almost 40% heavier than 10 kt gold, so feels as gold
should, - solid, and heavy!
10 kt and 14 kt alloys also make very nice items.
It usually comes down to price, with 10kt gold being around half
the price of 18 kt gold.
The choice is yours!!