A hallmark is an official mark or a series of marks struck onto objects made of precious metals. Precious metals are rarely used in their purest form but are usually alloyed with other metals for workability, durability, wearability. It is not possible to detect an article's precious metal content by sight or touch. Therefore, it is a legal requirement for an Assay Office in the UK to hallmark articles containing precious metals if they are described as such.

The term ‘hallmark’ originates from Goldsmiths’ Hall in London where silversmiths were required by law to take their items for assaying and marking from the 1327. As a ‘guardian of the craft’, the Goldsmiths’ Company Assay Office marked items that met the sterling silver standard with the leopard’s head – a symbol applied to this day by striking with a punch or using a laser.

There are four Assay Offices in the UK (London, Birmingham, Sheffield, Edinburgh) – none are Government run, and are private companies but overseen by the British hallmarking Council. The oldest Assay Offices are working from Royal Charters (London and Edinburgh).

A hallmark:

• Consists of a series of marks applied to articles of the precious metals platinum, gold, palladium and silver
• Means that the article has been independently tested
• Guarantees that it conforms to all legal standards of purity (fineness)
• Guarantees provenance by telling us, as a minimum legal requirement, where the piece was hallmarked, what the article is made from, and who sent the article for hallmarking. 

So don't forget to ask if a piece has been hallmarked, it's your guarantee.