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UK Precious Metals Reference Library

GoldPaid Knowledge Centre

The complete reference library for selling gold, silver and collectables in the UK. Explore hallmarking guides, XRF testing explanations, coin specifications and probate valuation advice.

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What would you like to explore?

GoldPaid’s Knowledge Centre provides transparent, evidence-backed answers to every question surrounding precious metals, hallmarking conventions, non-destructive testing and postal valuations.

Hallmarking & Purity Guides

Testing Methodology & Process

Probate, Collectables & Original Research

Common questions

How does GoldPaid test gold purity without scratching items?

We use non-destructive X-ray fluorescence (XRF) spectrometry. The XRF analyzer emits low-energy X-rays that cause the metal atoms to fluoresce, measuring exact element percentages (gold, silver, copper, zinc) without scratching, filing or acid-testing.

What is the difference between a hallmark and a karat stamp?

A UK statutory hallmark is an independent guarantee struck by one of the four UK Assay Offices (London, Birmingham, Sheffield, Edinburgh) verifying metal purity. A simple "375" or "18K" stamp applied by a manufacturer is a maker declaration, not a legal hallmark.

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