Knowing what to ask for is the difference between hoping and knowing. These are the organisations whose certifications, hallmarks and reports we encourage every buyer in Hatton Garden to look for before they commit.
A UK hallmark is the only legal mark for precious metal, applied by one of the four UK Assay Offices where required by law.
A laboratory report (GIA, IGI, HRD, SSEF, Gübelin and similar) is a respected expert grading or identification, not a UK legal hallmark.
Trade membership (NAJ, RJC, London Diamond Bourse) shows professional standing, not a government guarantee.
A lab-grown diamond must be described clearly as "laboratory-grown" or "laboratory-created", never just "diamond".
British institutions and trade associations that signal legal compliance and professional standing.
Oversees the UK hallmarking system; only the four UK Assay Offices may apply a UK hallmark.
London, Birmingham, Sheffield and Edinburgh: the four offices legally authorised to hallmark precious metals.
A historic London institution that has championed the craft and run hallmarking for centuries.
The UK's leading jewellery trade association; members follow its code of conduct.
Britain's gemmological body and one of the oldest gem and jewellery education providers in the world.
A UK diamond trade bourse, recognised by the UK government and a member of the WFDB.
A leading UK authority for jewellery, watch and silver valuers (part of the NAJ).
An independent UK and Ireland body for professional jewellery, gemstone and watch valuers.
Global bodies that set trade standards and responsible-sourcing expectations.
The primary international jewellery, gemstone and precious-metals association.
The global standards body for responsible sourcing, from mine to retail.
The official organisation of the international diamond trading sector.
Represents the industry within the Kimberley Process for natural-diamond integrity.
Regulates the rough-diamond trade to help prevent conflict diamonds (not a retail grading report).
Independent laboratories that grade a diamond on cut, colour, clarity and carat. These are expert reports, not legal hallmarks.
Top-tier natural-diamond grading and gemmology; reports verifiable on GIA Report Check.
Very common for natural and lab-grown diamonds, with online report verification.
Recognised European diamond grading and authentication.
Grades loose natural, untreated diamonds.
Technology-led diamond grading and light-performance reports.
Diamond, jewellery and gemstone reports with online verification.
A light-performance supplement to GIA reports (AGS Laboratories closed in 2022).
Specialist laboratories for sapphires, rubies, emeralds, spinel, jade and pearls, where origin and treatment matter most.
Leading reports for coloured stones, pearls and diamonds.
High-value coloured-stone origin and treatment reports.
Ruby, sapphire, emerald and spinel origin reports.
Coloured-stone origin and enhancement reports.
A respected niche lab for ruby, sapphire and spinel.
Identification and origin reports for coloured stones.
Hatton Garden Jewellers is an independent directory. Jewellers may list recognised trade memberships, UK hallmarking compliance, professional valuation credentials and independent laboratory reports. Laboratory reports from bodies such as GIA, IGI, HRD Antwerp, De Beers Institute of Diamonds, SSEF, Gübelin, GRS and similar institutions are treated as expert grading or identification reports, not as UK legal hallmarks. Precious-metal items must be hallmarked by a recognised UK Assay Office where required by UK law. We are not affiliated with, or endorsed by, any of these organisations, and we do not use their logos or act on their behalf.
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