What the number means
Think of gold as divided into 24 parts. 24K is 99.9 per cent gold. 18K is eighteen of those parts, so 75 per cent. 14K is 58.3 per cent. 10K is 41.7 per cent. Everything that is not gold is alloy: copper, silver, zinc, nickel or palladium, depending on the mix.
That alloy is also what makes the colours. More copper gives you rose gold. White metals plus a rhodium finish give you white gold. The karat number and the colour are two separate decisions.
What changes as the number goes down
- Colour. 18K is a deeper, richer yellow. 10K is noticeably paler because there is less gold in it to be yellow.
- Hardness. More alloy means a harder, more scratch-resistant metal. 10K stands up to daily knocks better than 18K does.
- Price. It tracks the gold content, which is why the same ring in 18K costs meaningfully more than in 14K.
- What sits against your skin. A lower karat means more alloy in contact with you. If a particular metal has caused trouble before, say so before we quote, because palladium, white gold, and platinum are all straightforward alternatives.
What we would put on a hand that never comes off
14K is the working answer for most engagement rings and wedding bands, and it is what we recommend most often. There is enough gold in it to look and wear like gold, and enough alloy in it to survive a decade of door handles, steering wheels and kitchen counters.
18K is for someone who wants the richer colour and understands they are choosing a softer metal. 10K makes sense where budget is the deciding factor, or where the piece takes genuine abuse.
Reading the stamp inside the band
Look inside the shank. You will find 10K, 14K or 18K, or the decimal equivalents used internationally: 417, 585 and 750. Those are the same numbers as the percentages above, expressed in parts per thousand.
If you have an older piece and cannot find a stamp, bring it in. A stamp can wear away entirely after decades of sizing and polishing, and testing it takes a minute at the bench.
