Hallmarking


What Is Hallmarking?

A hallmark is a stamp, or series of stamps, applied to jewellery made from certain precious metals and over specific weights. Hallmarking in the UK dates back to the 1300s, when jewellery was taken to Goldsmiths’ Hall in London to be tested and punched with a mark showing the fineness of the metal. This is where the term hallmark originates.

The purpose of hallmarking is to protect the consumer from purchasing jewellery that does not meet legal fineness standards. It also gives makers confidence that the materials they are sourcing and working with are of the correct quality.

In the UK, silver jewellery weighing more than 7.78 grams and gold jewellery weighing more than 1 gram must, by law, be hallmarked. There are other precious metals that also require hallmarking, but as Sketchy Bones works with silver and gold, these are the metals outlined here.

Any jewellery that meets or exceeds these weights, and is made and/or sold in or from the UK, must be hallmarked.



UK Assay Offices

Hallmarking is carried out by independent, third-party organisations known as UK Assay Offices, which act on behalf of the law. There are only four cities in the UK with an Assay Office:

  • Birmingham

  • Edinburgh

  • London (two offices)

  • Sheffield

Sketchy Bones takes its jewellery to the London Assay Office at Goldsmiths’ Hall to be hallmarked.

All Sketchy Bones jewellery is hallmarked except for silver ear studs. Due to their very light weight, these studs fall below the legal requirement for hallmarking. Instead, they are stamped “925”, which helps keep their cost as low as possible. However, silver ear studs can be hallmarked upon request, for an additional fee.



What Does A UK Hallmark Show?

A UK hallmark is a series of small stamps that together tell the story of a piece.
These marks indicate:

  • The maker’s mark (SBC for Sketchy Bones Collective).

  • The metal and its fineness.

  • The Assay Office where it was hallmarked (London is represented by a leopard’s head).

  • A date letter showing the year the piece was hallmarked.

Date letters run in 25-year cycles, with a new font introduced at the start of each cycle. The letters I and J never appear in the same cycle, as they look too similar.
For example, 2026 will be represented by the letter B.



Why Hallmarking Matters

The UK hallmark is a remarkable system. Not only does it provide legal consumer protection, it allows a precious metal object to be traced to a specific place and moment in time.
That connection to history, preserved in a few tiny marks, is both beautiful and important.