What is a hallmark?
A hallmark is a series of small stamps applied to precious metal items by an independent UK Assay Office. It is the consumer’s protection — an unbiased third-party verification that the gold content of a piece matches its description. In the United Kingdom, it has been a legal requirement since 1300.
The five marks on your GCB piece
Every full UK hallmark is composed of five elements:
Sponsor’s mark — the registered initials of GCB Jewellery, identifying who submitted the piece.
Metal & fineness mark — a number indicating the parts of pure precious metal per thousand. 750 for 18ct gold, 916 for 22ct gold.
Assay Office mark — a leopard’s head for London, where every GCB piece is tested.
Date letter — the year the piece was assayed (optional, but always included on GCB pieces).
Traditional fineness mark — the gold crown, signifying gold.
Gold purity, plainly explained
22ct (916) — 91.6% pure gold. Rich in colour, soft to the touch — the gold of the Dubai souks and of generations of family pieces.
24ct (916) — 91.6% pure gold. Rich in colour, soft to the touch — the gold of the Dubai souks and of generations of family pieces.
Your certificate of authenticity
Alongside the physical hallmark, every GCB piece is delivered with a signed certificate of authenticity recording the metal, weight, any stones and their grading, and the original London assay date. Keep this document with the piece — it forms part of its provenance, and is required for insurance and resale.
Verifying your piece
You can independently verify any UK hallmark via the Assay Office London’s public register. We will gladly assist any GCB client who wishes to do so — simply contact our concierge.
