Jewellery
The Complete Guide to Gold Purity — 9k, 14k, 18k, 22k, 24k Explained
Reviewed by Thomas & Øyvind — NorwegianSpark | Last updated: April 2026
The Karat System Explained
The karat system measures gold purity in 24 parts. 24k is 99.9% pure gold. Because pure gold is too soft for durable jewellery, it is alloyed with other metals. 22k is 91.6% gold, 18k is 75%, 14k is 58.5%, 9k is 37.5%. The higher the karat, the richer the colour and the greater the metal value — but also the softer the piece.
Fineness Table
24k = 999 fineness. 22k = 916. 18k = 750. 14k = 585. 9k = 375. These numbers appear on the hallmark and are the same across the UK, EU, and internationally recognised jurisdictions.
Colour Varieties
Yellow gold is alloyed with silver and copper and gives the traditional warm tone. White gold is alloyed with palladium or nickel and plated with rhodium for a bright silver appearance; the plating wears and needs renewal every few years. Rose gold uses a higher proportion of copper for its pink tone.
Which Karat for Which Purpose
For pure investment: 22k or 24k bars and coins. For fine daily jewellery: 18k, the standard for luxury makers. For active wear where durability matters most: 14k or 9k. For watches: always 18k — the industry standard for gold cases.
Resale Reality
9k jewellery is valued at 37.5% of spot gold as a floor; 18k at 75%. Signed pieces from Cartier, Tiffany or Van Cleef & Arpels sell above that floor — sometimes well above. Unsigned pieces trade close to metal content. If you want pure metal exposure, bullion from a dealer like SilverGoldBull is more efficient than jewellery.
Related Collections
Where to Buy
Frequently Asked Questions
Is 24k gold worth buying as jewellery?
Pure 24k is very soft and dents easily, which is why it is rarely used for rings or bracelets. It is the standard for investment bars and many Asian-market pieces, but for Western jewellery 18k or 22k is the practical upper limit.
What is the difference between white, yellow and rose gold?
All three contain the same amount of gold (for the same karat). The colour comes from the alloy: yellow uses copper and silver, white uses palladium or nickel and is rhodium-plated, rose uses a higher proportion of copper.