Reading Gold Hallmarks Country by Country
The tiny stamps on your gold tell you its purity, its origin, and sometimes that it is not gold at all.
A hallmark is a small official stamp, usually tucked on the clasp of a chain, the inside of a ring, or the post of an earring. Read correctly, it tells you the purity of the piece and often the country and workshop that made it. Read carelessly — or not at all — and you can mistake gold-plated brass for solid gold. This guide walks through the hallmark systems you are most likely to encounter and the marks that should make you stop.
The universal language: millesimal fineness
Most modern hallmarks express purity as a three-digit number — the millesimal fineness, or parts per thousand of pure gold. This is the closest thing the world has to a universal gold language, and once you know the common values you can read a purity stamp from almost any country:
- 999 or 9999 — 24K, essentially pure gold
- 958 — 23K
- 916 — 22K (58.33% would be wrong here; 916 is 91.6%)
- 875 — 21K
- 750 — 18K
- 585 — 14K
- 417 — 10K
- 375 — 9K
- 333 — 8K
If you can read that three-digit number, you already know the single most important fact about a piece: how much gold is in it. Everything else in a hallmark is supporting detail.
United Kingdom: the full assay hallmark
The UK runs one of the oldest and strictest hallmarking systems in the world, and a fully marked British piece is among the best-authenticated gold you can buy. A complete UK hallmark has several components struck together:
- Sponsor's mark — the maker or importer, shown as initials in a shield.
- Fineness number — the millesimal purity (750, 585, 375, etc.) inside a shaped surround.
- Assay office mark — a symbol showing which office tested it: a leopard's head for London, an anchor for Birmingham, a rose for Sheffield, a castle for Edinburgh.
- Date letter — a letter in a distinctive font indicating the year of assay (optional since 1999 but often present).
The assay office does not take the maker's word for the purity — it independently tests the metal before applying the mark, which is why UK hallmarks carry so much weight.
United States: karat stamps, lightly regulated
The US uses karat stamps rather than millesimal numbers on most domestic jewelry: 10K, 14K, 18K, 24K, sometimes written as "14KT" or "585." US law requires that a karat stamp be accompanied by a registered maker's trademark, because under the National Gold and Silver Stamping Act a maker who stamps a karat must stand behind it. Unlike the UK, there is no government assay office; enforcement is by the maker's liability. As a practical matter this means US karat stamps are usually reliable for reputable manufacturers but occasionally optimistic on cheap imports. A stamp with no accompanying trademark is a small warning sign.
India: the BIS hallmark
India's hallmarking is run by the Bureau of Indian Standards (BIS). Since mandatory hallmarking was rolled out, a compliant piece carries the triangular BIS logo, the fineness number (usually 916 for 22K, sometimes 750 or 585), and a six-character alphanumeric HUID (Hallmark Unique Identification) code. The HUID lets a purity be traced back to the specific assaying event, which sharply reduced under-karating in the Indian retail market. If you buy 22K in India, look for the BIS triangle and the 916 mark together.
Continental Europe and the Middle East
Most of continental Europe uses millesimal numbers, often with a national control mark. Italy adds a maker's mark with a province code. The Gulf states typically stamp 999, 916, 875, or 750 depending on the piece, with 875 (21K) especially common in Saudi Arabia. Turkey stamps 916, 585, and 375, and traditional pieces are sometimes marked "has" for pure gold. The three-digit fineness is the constant you can rely on across all of them.
Stop and check: these marks mean the item is not solid gold. GP = gold plated. GF = gold filled. RGP = rolled gold plate. HGE = heavy gold electroplate. 1/20 12K or similar fractions = a thin gold layer over base metal. And 925 is sterling silver, not gold at all.
What a hallmark cannot tell you
A hallmark declares purity, but it is a claim, not a guarantee against forgery. Counterfeiters do stamp fake marks. A genuine-looking hallmark plus a passed magnet test plus a plausible weight-to-size ratio is a strong combination, but for anything valuable the definitive answer still comes from an XRF scan at a jeweler. Treat the hallmark as the opening piece of evidence, not the verdict — our guide on how to test if gold is real covers the confirming steps.
Putting it to use
When you pick up any gold item, do three things in order: find the stamp, read the three-digit fineness (or karat), and scan for a plating code. Those three seconds tell you whether you are holding 22K bullion-grade gold, 9K everyday jewelry, or plated brass. Once you know the purity, drop the weight and karat into the calculator to see what the metal is actually worth.