What Does 375 Mean on Jewelry?

The 375 hallmark indicates that a piece of jewelry contains 375 parts per thousand of pure gold — the equivalent of 9 karats. This is the lowest karat gold that can legally be sold as 'gold' in the United Kingdom, Ireland, Australia, and several other countries. The remaining 62.5% of the alloy is made up of metals such as copper, silver, zinc, and sometimes nickel, which give the piece its strength and influence its color.

Nine-karat gold is extremely popular in the UK and Australia, where it offers an affordable entry point into genuine gold jewelry. Because it has the highest alloy content of any gold standard, 9K gold is the hardest and most scratch-resistant gold alloy available. This makes it exceptionally durable for everyday rings, bangles, and chain bracelets that take a lot of punishment.

The lower gold content does affect the color — 9K gold has a noticeably lighter, paler yellow tone compared to 14K or 18K gold. Some people prefer this subtler look, while others opt for rose gold formulations of 9K, where increased copper creates a warm pinkish hue. It is worth noting that 9K gold is not recognized as a legal gold standard in the United States, where the minimum is 10K (41.7%). This means 375-stamped jewelry imported to the US cannot be marketed as 'gold' under FTC guidelines.

Check inside ring bands, on clasps, and on tags near closures. In the UK, 375 gold will typically be accompanied by a full set of hallmarks including the assay office mark (anchor for Birmingham, leopard's head for London, rose for Sheffield, castle for Edinburgh) and a maker's mark. These hallmarks provide authentication that the gold content has been independently verified by an assay office.