Hallmark fineness marks explained

Every fineness mark the UK Hallmarking Act 1973 recognises for gold, silver, platinum and palladium: the figures struck on the piece and how much precious metal they guarantee. Carat equivalents are the fineness times 24, divided by 1,000.

Hallmark fineness marks explained
HallmarkFigures struckMetalPrecious metal contentGold carat equivalent
375 gold375Gold37.5% gold9.0 carat
585 gold585Gold58.5% gold14.0 carat
750 gold750Gold75% gold18.0 carat
916 gold916Gold91.66% gold22.0 carat
990 gold990Gold99% gold23.8 carat
999 gold999Gold99.9% gold24.0 carat
800 silver800Silver80% silver
925 silver925Silver92.5% silver
958 silver958Silver95.84% silver
999 silver999Silver99.9% silver
850 platinum850Platinum85% platinum
900 platinum900Platinum90% platinum
950 platinum950Platinum95% platinum
999 platinum999Platinum99.9% platinum
500 palladium500Palladium50% palladium
950 palladium950Palladium95% palladium
999 palladium999Palladium99.9% palladium

Sources

Jewelry Identifier