What Does “Hallmarked” Really Mean? Why It Matters for Your Jewellery

At John Garland Taylor, we’re often asked: “Are your pieces hallmarked?” The short answer is yes - but the story behind hallmarking is worth understanding, especially if you're investing in solid gold or sterling silver jewellery.

What Is Hallmarking?

Hallmarking is the official process of verifying the purity of precious metals like gold and silver. In the UK, it’s a legal requirement for any jewellery being sold as gold or silver above a certain weight.

Since 1993, UK law has required that all gold and silver jewellery weighing over a certain threshold must be tested and hallmarked by an official Assay Office to confirm its metal content. 

Is JGT Jewellery Hallmarked?

Yes. All of our solid 9ct gold jewellery is hallmarked, and our sterling silver jewellery is hallmarked when it exceeds 7.78g, in accordance with UK law. Even our lighter silver pieces - while exempt - are made to the same high standards using solid 925 sterling silver. 

What’s in a Hallmark?

Each hallmarked piece from John Garland Taylor contains three official marks;

• Sponsor’s Mark - Identifies the maker (that’s us: JGT).
• Standard Mark – Confirms the metal’s purity: 925 for sterling silver 375 for 9ct rose and yellow gold
• Assay Office Mark – Ours is the Birmingham Assay Office, represented by the Anchor symbol.

How Does Hallmarking Work Today?

Modern hallmarking is a precise, science-backed process. Each piece is tested using X-ray fluorescence, which “excites” the metal atoms to measure the percentage of each element within the alloy.

This gives an accurate, non-destructive reading of the metal’s composition. Once verified, the Assay Office will apply the hallmark either by laser engraving or traditional hand-stamping, depending on the piece.

Handmade. Hallmarked. Hand-Delivered.

Each week, David personally drives to the Birmingham Assay Office with a batch of our handcrafted jewellery - and collects newly hallmarked pieces ready for their next journey: to you.

This hands-on approach reflects our values - attention to detail, local partnerships, and a promise of quality you can trust.

Ask Us Anything

Have a Question? Got a question about our materials, processes, or anything jewellery-related? We love hearing from our customers. Drop us a message - your question might be featured in our next blog or social post!