Hallmark
Definition
An official mark stamped on precious metal jewelry by an assay office or manufacturer, certifying its metal purity (fineness), origin, and authenticity.
Hallmarking is a centuries-old system of consumer protection that guarantees the precious metal content of jewelry. A complete hallmark typically includes: the maker's mark (identifying the manufacturer), the fineness mark (metal purity — e.g., 750 for 18k gold, 925 for sterling silver, 950 for platinum), the assay office mark (the testing authority), and sometimes a date letter. Hallmarking requirements vary by country — it is mandatory in the UK, much of Europe, and India, but voluntary in the US where the karat stamp system is used instead. The Goldsmiths' Hall in London, established in 1300, is where the term 'hallmark' originated. Modern hallmarks are typically applied by laser rather than traditional punching.
Usage in the Trade
Hallmarks are found on all precious metal jewelry in countries where hallmarking is mandatory. Jewelers, dealers, and consumers use hallmarks to verify metal purity and manufacturer identity.