This is one of the most common questions we get asked and we hope that this guide will help you to set them apart.
Metal Content
Gold in its purest form - 24ct, is too soft to use in jewellery and that’s why it gets mixed with other metals to create an alloy that is suitable for jewellery. 18ct gold consists of 75% fine gold and 25% alloy metals and 9ct gold consists of 37.5% fine gold and 62.5% alloy metals.
Value
18ct gold has double the amount of gold content, compared to 9ct gold. The higher gold content makes the metal more valuable and also gives it a richer, more luxurious feel. See the image below of a custom anniversary band featuring seven diamonds, flush set in 18ct yellow gold.
9ct gold is the most affordable option and is a good choice for those looking for gold jewellery on a budget.
Hardness & Durability
There is a common belief that 9ct gold is harder than 18ct gold, but this is actually not true. Metal hardness is measured according to the Vickers scale and 18ct gold ranks higher than 9ct gold. 9ct gold contains a higher percentage of alloy metals which makes the metal more brittle and less resistant to knocks and scratches. When compared over a longer period of time, 18ct gold will last better and is more valuable.
Appearance
When comparing the visual appearance between 9ct and 18ct gold, there is a difference in their colour intensity and warmth. 18ct yellow gold, has a higher gold content which gives the metal a rich yellow hue that’s more vibrant and luxurious. 9ct yellow gold has less gold content in the alloy, which gives the metal a soft, muted yellow colour like this custom Toi Et Moi ring we made for a customer.
Final Thoughts
Now that you know the difference, you can make an informed decision of what metal is best for you. We always recommend going for 18ct gold or platinum for rings that you’re going to wear every day or for heirloom worthy pieces. 9ct gold is a good option for a dress ring or a piece that you’re not planning to wear daily.
At Kolmio, we work with both alloys so that our customers can choose the best metal that suits their needs and preferences. If you have any questions or need guidance on choosing the right metal or jewellery piece for you, reach out to us.