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A Jeweller’s Guide to Different Types, Colours & Carats of Gold

What are ‘gold alloys’ and ‘carats’ - and which is the best type of gold to choose for your jewellery?

When it comes to choosing gold jewellery, and creating bespoke pieces, the choice of different golds, stones and styles is astounding. I’m making it easier for you by explaining the different types of gold in user-friendly terms, helping you understand which one most suits your lifestyle.

What does ‘Carat' mean?

‘Carat’ or ‘Karat’ is the term used to measure the purity of gold alloys.

An alloy means the final composition is made up of a mix of metals. This could be gold, silver, copper, etc… the list goes on. Alloying (adding other metals to) fine gold allows the jewellery to have different properties. Different alloys allow for variation in the strength, colour and durability. And variety is the spice of life! 

Carat (ct) refers to the amount of fine gold within the alloy. Fine gold is really beautiful, but very soft, meaning it’s not particularly hardwearing and would likely mark and distort easily during wear. This is why alloying it with other metals is necessary. 

How much fine gold is in each carat?

  • 24ct Gold contains 99.9% fine gold

  • 22ct Gold contains 91.6% fine gold

  • 18ct Gold contains 75% fine gold 

  • 14ct Gold contains 58.5% fine gold

  • 9ct Gold contains 37.5% fine gold

What Colours does gold come in?

All pure gold is yellow. 99%+ fine gold has the warmest, sunniest hue you ever did see. It’s not surprising that humans have been fascinated with it for 1000’s of years. As I mentioned, fine gold is alloyed down, and there are three main tones of gold alloy in use today:

  • Yellow Gold

  • Red/Rose Gold

  • White Gold 

But you might also encounter peachy golds, green gold, blue gold and even purple gold. Being a jeweller at times is a lot like being a scientist!

Yellow Gold

Yellow gold is the traditional gold that comes to mind when you think of a gold nugget or gold jewellery. It looks like a pool of molten sunshine, is full of warmth, and is beautifully eye-catching against the skin. 

Yellow golds are made of different ratios of fine gold, fine silver, and copper. The copper and silver are added in equal measure to preserve the yellow colour (if this is desired).

A set of rings showing different colours of yellow gold
Yellow Gold Carat Colours

Different Carats of Yellow Gold 

  • 9ct Yellow Gold - Contains 37.5% fine gold. This creates a less dense, lighter alloy which can mark more easily than others. Due to the high copper content, it’s also possible that this gold will tarnish. However, this is probably the most used alloy in the UK, as it still contains a healthy proportion of fine gold, yet is more affordable when compared to other carats. 

  • 14ct Yellow Gold - Typically seen in jewellery made in the USA, 14ct yellow gold is just over 50% fine gold, meaning it’s dense and durable.

  • 18ct Yellow Gold - This is a  fantastically dense and durable alloy, containing 75% fine gold. It’s an excellent option for wedding rings and pieces worn daily, with the high fine gold content remaining, but durability and strength acquired from the small amount of silver and copper that is added to it. 

  • 22ct & 24ct Yellow Gold - Although you might have thought the highest carats of gold meant are for the most desirable jewellery, this isn’t quite the case. 22ct and 24ct yellow gold are very soft, and it isn’t often considered suitable for jewellery except as plain 22ct wedding rings, or dress pieces. 

Red/Rose Gold

In recent years there has been a growing demand for red gold. Red gold is also known as ‘rose gold’ due to its pretty pink hue. Red gold is made from different ratios of fine gold, fine silver and copper, but with a higher copper content which gives the touch of red. 

Different Carats of Red/Rose Gold 

  • 9ct Red Gold - The lower amount of fine gold here allows for a higher amount of copper. Therefore 9ct red gold has the reddest colour of all the red alloys, which is perfect for those looking for the rosiest red golds. Because of the high copper content it can be prone to tarnishing, but is durable enough for earrings, pendants, and rings. 

  • 18ct Red Gold -  This is a beautiful delicate red colour. It’s an alloy that can be challenging to work with and is prone to being brittle, but in the right hands it’s durable enough and best suited to plain rings or pieces like earrings which won’t get heavy wear.

  • 22ct Red Gold - As much of this alloy is fine gold, it’s very soft and has a subtle, rosey tone thanks to the small copper content. It’s really only suitable for plain wedding rings or heavy weight bangles.