What Is 'Karat' In Gold Jewellery?

Karat is a jewellery-industry term used to describe the purity of gold. When you’re shopping for 9-karat, 14-karat, or 18-karat jewellery, you’re browsing different variations of gold in terms of purity, quality, and value. 

What does ‘karat’ mean?

In its pure form, gold is a very soft metal. This makes it an easy material to work with — gold can be bent and shaped to form both simple and complex designs for jewellery. However, this also means that jewellery with a high purity of gold is prone to damage from knocks and bumps that can bend it out of shape. 

To solve this issue, jewellers combine gold with other precious metals to strengthen it and increase its durability. Over time, these combinations have settled into several fixed compositions that we know today in the form of different gold karats. 

Understanding karats & gold purity

The higher the karat of gold jewellery, the higher the purity of gold. This doesn’t necessarily mean that low-karat gold is ‘impure’ — it means that there is a lower percentage of gold present in the alloy. Here’s a guide to the different mixtures of gold ideal for gold jewellery:

9k Gold

9 karat gold consists of 37.5% pure gold, with the remaining 62.5% being made up of metals like silver or copper. 9k gold is almost never seen in fine jewellery — the low purity of gold used in 9k jewellery makes it hold much lower value in comparison to higher karat gold jewellery. 

14k Gold

14-karat gold is made from 58.65% pure gold. This level of gold purity offers much greater resistance to scratches and general wear and tear than higher karat grades, making it an ideal choice of gold jewellery metal for those who lead active lifestyles and wear their gold jewellery every day. 

18k Gold

18-karat gold is quite literally the gold standard for fine gold jewellery. Most engagement rings, wedding rings, and diamond necklaces come in 18k gold options. 18k gold is composed of 75% pure gold, which gives it a fine balance between durability and gold quality. 

22k Gold

22k gold contains 92% pure gold — this is the highest gold karat grade that is used in fine jewellery. The 8% precious metal alloy used in 22k gold gives it slightly more durability compared to pure gold, but not enough to be worn carelessly without sustaining damage. 22k gold jewellery must be handled and worn carefully as it is more delicate and softer than other commercial-grade gold alloys mentioned above. 

24k Gold

24-karat gold is considered the purest and most refined form of gold. Many sources claim that 24k gold is 100% pure gold, but the actual percentage of gold is usually closer to 99.9%, depending on how much the gold has been chemically treated to remove impurities. 24k gold is far too soft to be used in fine jewellery, which is why it is usually traded as a precious commodity rather than worn. 

Gold colours and karat composition 

Gold jewellery has come a long way since ancient times — in addition to the classic yellow gleam that is expected with gold, jewellers now offer gold jewellery in white gold and rose gold. White and rose golds are created by mixing in different types of metals to transform the natural yellow-lustre of gold to the silvery shine of white gold or the pinkish-hue of rose gold. 

The gold karat of jewellery stays consistent regardless of its colour. An 18k white gold engagement ring will still contain 75% gold — the remaining 25% is where jewellers add or adjust various metals like copper, platinum, nickel, and zinc to achieve the ideal colour. 

How to tell the karat of gold jewellery 

It’s possible to determine the purity of gold without having to take the jewellery to a jeweller or an appraiser. Most jewellers include a number stamp on the piece as proof of the purity of gold. The stamped number can equate to a karat measurement:

Is it ‘karat’ or ‘carat’?

Both ‘karat’ and ‘carat’ are often used interchangeably in jewellery — while they make it seem like spelling variations of the same word, they refer to different things. 

‘Karat’ refers to the purity of gold, where ‘Carat’ refers to the weight of a diamond.