What do the different numbers found stamped inside items of fine jewellery actually mean?

Parts per thousand indicating the fineness of the metal are referred to as the Standard Mark.

Maker            % Platinum          % Silver         % Palladium            % Gold Colour           Assay

Guide to precious metal grades and hall marks from Pobjoy Diamonds

For example .925 silver denotes that the item of jewellery is made from 92.5% silver. The remaining 7.5% typically includes copper and zinc which is combined with the pure silver.

In the UK most gold jewellery is either 9 carat ("9K") or 18 carat. In Europe and the USA 14 carat gold is more prevalent.

There are four main UK Assay Offices responsible for independently standardizing precious metal grading, by evaluating compliance with the required stringent criteria.

In aggregate, the Assay Offices hallmark approximately ten million articles each year.

Pobjoy Coat of Arms

Of these assay institutes, The Sheffield Assay Office is responsible for stamping the iconic Pobjoy "PM" maker's mark on each of our diamond rings and bespoke jewellery.

This is your peace of mind that each of our creations meet the highest independent quality standards.