Understanding Jewelry Hallmarks

Hallmarks are the DNA of fine jewelry — tiny stamps pressed into metal that tell you exactly what you're holding. Understanding them is essential for any collector, whether you're buying at auction or evaluating a family heirloom.

Purity Marks

The most common hallmarks indicate metal purity. For gold: 750 means 18k (75% pure gold), 585 means 14k, and 375 means 9k. For silver: 925 means sterling silver (92.5% pure). For platinum: 950 means 95% pure platinum.

Maker's Marks

Most luxury jewelry houses stamp their pieces with a maker's mark — often initials inside a specific shape. Cartier uses an eagle's head, Tiffany uses 'T&Co', and Van Cleef uses 'VCA'. These marks authenticate the piece and connect it to its manufacturer.

Assay Office Marks

In many countries, independent assay offices verify metal purity and stamp their own marks. British hallmarks include the city mark (a leopard's head for London, an anchor for Birmingham), while French hallmarks use an eagle's head for 18k gold.