9k gold is 37.5 percent pure gold, mixed with harder metals like copper and silver to give it strength. It is the most affordable solid gold sold in the UK, noticeably cheaper than 14k or 18k for the same design, and it carries a full UK hallmark as real gold.
The trade off is colour and feel. 9k has a paler, slightly cooler tone than 14k or 18k, and because the alloy content is higher, it can react with skin chemistry or perfume more readily. It also shows fine surface scratches more than higher karat gold, though the alloy makes it harder by some measures.
For an everyday piece you will wear hard, 9k is a sensible choice. We use solid 9k across most of our everyday rings, everyday necklaces and everyday earrings for exactly that reason, including pieces like the Alba 9k Gold Stud Earrings. For an engagement ring, wedding band or heirloom, most people prefer the warmer colour and higher gold content of 14k or 18k, which is where our engagement ring collection sits.
If you are weighing the two higher purities against each other, our guide to 14k versus 18k gold for a ring covers the difference in detail. To compare all three in person, book a consultation at our Hatton Garden studio.