Back-to-basics: Carats of Gold

For the second part of my back-to-basics blogs series, I will be discussing carats of gold. If you’re like me, once oblivious to what and how carats of gold are categorised, then this should be super helpful for you! It’s actually really simple, who knew!


A carat of gold derives from the Germans in 1873. They created a coin called the mark. This coin weighed 24 carats (carats is also a unit of weight – just to make things a little more complicated). The purity of gold within the mark was then listed as the number of carats of gold, in this 24 carat weighted coin.


Carats are used to measure how much actual gold is in your gold jewellery. To be more specific, one carat is equal to 1/24th part of pure gold in an alloy. Not too complexed, right?

So what are the different carats?

So, this means that 24ct is 100% gold. The purest form of gold. However, 24ct jewellery aren’t very durable and very expensive due to it having the highest gold content. Hence why 9 and 18 carats are more in demand.

22ct gold is 91.67% gold. Like 24ct, 22ct gold is also very soft so it's not very appropriate for stone-set jewellery and so is often used in plain gold jewellery.

18ct is 75% gold with 25% of various other metals which may include, platinum, zinc, silver, platinum or copper. 18ct gold is a great choice if you’re looking for a fine jewellery piece that will be worn frequently and needs to last as long as possible, such as a wedding band.

Now, 15ct, not seen this before? Here’s why…15ct was a legal standard between 1854-1931. 12ct was also used during this time and these then were both replaced with 14ct in 1932. This means if you find or own any jewellery pre 1932 you’re super lucky! These are true antique pieces.

14ct gold is 58.3% gold. 14ct gold jewellery is usually less expensive than higher carats of gold and is more durable due to the higher percentage of alloy metals.

You guessed it…9ct is 37.5% gold with 62.5% of various other metals described above, depending on whether it’s a white, yellow or rose gold piece. 9ct gold are obviously great if you are looking for a piece with a lower budget and can also be worn frequently as they consist of higher percentage of other metals, making them less easily scratched or tarnished.

As a summary, when choosing your jewellery consider how often you will wear the piece and thus how long does it need to last, as well as budget and appearance. This will impact the karat of gold you should choose as well as the colour.