by Lea NogueiraPortuguese hallmarks: how to read the marks on gold and silver jewellery
The tiny stamps on gold and silver jewellery say a lot. Learn what they guarantee, where to find them and what they mean.
Pick up a Portuguese gold or silver jewel and look at it under a loupe, and you'll probably find tiny stamped marks: symbols, letters, numbers. They're not decoration — they're an official guarantee. Portugal's assay system is one of the oldest and strictest in Europe, and knowing how to read it helps you buy with confidence.
What the assay office is
The assay office (contrastaria) is the official service that tests the fineness of precious metals — how much gold, silver or platinum a piece contains — and marks pieces that comply with the law. In Portugal, assay offices operate in Lisbon and Porto, under the national mint, Imprensa Nacional-Casa da Moeda.
In practice, precious-metal jewellery sold in Portugal must go through this control and be marked. There are exceptions for very light pieces and specific situations set out in law.
The two main marks
Responsibility (maker's) mark
It identifies who made the piece or put it on the market: the goldsmith, the workshop or the importer. Each has a registered mark, usually initials and a small symbol. It tells you who answers for the piece.
Guarantee (assay) mark
Applied by the assay office after testing the fineness. It indicates the metal and legal standard, and its design varies with the metal, the standard and the office that tested it. It guarantees the piece contains at least the stated precious-metal content.
Where to look
- Rings: inside the band.
- Earrings: on the post, the back or the hoop.
- Necklaces and bracelets: on the clasp or a small tag next to it.
- Pendants: on the back or the bail.
The marks are tiny. Use a 10x jeweller's loupe and good light.
How to read them
Portuguese official marks have changed several times through history, and the design often helps date a piece. The designs of each period are documented in tables published by the national mint and in reference books on Portuguese silver and goldsmithing.
For everyday purposes, three things are enough:
- A new gold or silver piece sold in Portugal should have both marks.
- Numbers like 925 (silver) or 800 and 750 (gold) give the fineness in parts per thousand. Read more in 925 silver, sterling and gold plating explained.
- A stamp reading only "925" or "18K", without an official mark, is the maker's statement — not an official Portuguese guarantee.
What about antique pieces?
Many antique pieces carry marks from earlier periods with different designs. Others have none, because they predate the current system, the marks wore off, or they were repaired. A missing mark on an old piece doesn't by itself mean it isn't gold or silver — but it calls for an assessment.
Why it matters
- Buying with confidence: the mark guarantees the metal you're paying for.
- Repair and remodelling: knowing the fineness is essential to choose the right solder and to remodel heirloom gold.
- Resale or valuation: marked pieces are easier to value.
At Ignis
Our pieces are made in 925 silver and some are gold-plated, always stated in each description. If you're unsure about the metal of a piece you want repaired or remodelled, send us a photo through the contact page.
