Gold Hallmark Identification: What the Stamps Mean

What a Hallmark Actually Is

A hallmark is a mark applied to a precious metal item to record its purity, and, in regulated markets, to record who made it and which assay office certified it. In the strictest sense the term refers only to marks applied by an official assay office after independent testing, as in the UK or India's BIS system. In everyday use it covers any purity stamp, including manufacturer-applied ones.

That distinction matters. An official assay mark is backed by a legally accountable third party. A manufacturer's stamp is a claim by the seller. Both are useful, but only one is evidence.

The Millesimal Numbers

Most modern gold is marked with a three-digit number giving purity in parts per thousand.

Mark	Purity	Karat	Where you'll see it
999 / 999.9	99.9%+	24K	Bullion bars and coins, investment jewelry in East Asia
995	99.5%	~23.9K	Good delivery bars, some Middle Eastern jewelry
990	99.0%	~23.8K	Chinese "chuk kam" jewelry
958	95.8%	23K	Rare; some Indian and Gulf pieces
916 / 917	91.6%	22K	The dominant mark on Indian, Gulf and South Asian jewelry
875	87.5%	21K	Middle Eastern and North African jewelry
833	83.3%	20K	Occasional in Middle Eastern markets
750	75.0%	18K	European fine jewelry, luxury watches, designer pieces
585 / 583	58.5%	14K	The US mainstream; durable everyday jewelry
417	41.7%	10K	US budget jewelry and class rings
375	37.5%	9K	UK, Ireland and Australia; the statutory minimum for "gold" under the UK Hallmarking Act 1973

Note that 916 and 375 are the two you will meet most often worldwide, for very different reasons: 916 dominates the South Asian and Gulf jewelry trade, where gold is bought partly as savings, while 375 is common in the British market, where durability and price matter more than metal content. We have a dedicated explainer on what 916 means.

Karat Stamps

Older and American pieces often use the karat number directly: 24K, 22K, 18K, 14K, 10K. British and Commonwealth pieces sometimes use 22ct, 18ct, 9ct. They mean exactly the same as the millesimal equivalents above. See our karat guide for the full comparison.

Country and Assay Office Marks

Alongside the purity number you will often find a second symbol identifying who certified the piece.

India (BIS): Under the Bureau of Indian Standards hallmarking order phased in from June 2021, hallmarked gold carries the BIS logo, the purity in karat and fineness (e.g. "22K916"), and a six-digit alphanumeric HUID code unique to that item.
United Kingdom: A full hallmark has a sponsor's mark (the maker), a fineness number in an oval or shield, and an assay office town mark: a leopard's head for London, an anchor for Birmingham, a rose for Sheffield, a castle for Edinburgh.
Switzerland: A St Bernard dog head for imported goods; case makers' marks on watch cases.
Italy: A star followed by a numeric "fabbrica" code identifying the manufacturer and province, for example "750" beside "123 VI" for a Vicenza maker.
France: An eagle's head for 18K gold; older pieces carry a range of historical figures.
United States: No mandatory assay office. Purity stamps are applied by the manufacturer, and the National Gold and Silver Stamping Act requires an accompanying registered trademark.

Practical tip: Photograph the stamp with your phone's macro mode and pinch to zoom. A phone screen reveals tiny marks far more reliably than squinting through a loupe, and you get a permanent record for your insurance file.

Marks That Mean It Is NOT Solid Gold

This is where most people get caught out. These stamps indicate a gold layer over a different metal:

Mark	Meaning	Actual gold content
GP	Gold plated	A microscopically thin layer; negligible value
GEP	Gold electroplated	Thin electroplated layer; negligible value
HGE / HGP	Heavy gold electroplate	Thicker plating, still very little metal
GF / 1/20 12K GF	Gold filled	A bonded layer, typically 1/20th of total weight
RGP	Rolled gold plate	Thinner than gold filled
Vermeil	Gold over sterling silver	Silver value plus a thin gold layer
925 with gold color	Sterling silver, gold plated	Silver value only

If you see any of these, the piece has silver or base-metal value, not gold value. Our guide to telling gold from brass and plating goes into the physical tests.

How to Spot a Forged Hallmark

Forged stamps are common on counterfeit jewelry and bars. Look for:

Sloppy, uneven or shallow characters. Genuine stamps are crisp and consistently struck; forgeries often look smeared or hand-scratched.
The wrong mark for the market. A "916" on a piece styled as European fine jewelry, or a BIS mark with no HUID code on a post-2021 Indian piece.
A purity stamp with no maker's mark in markets where both are legally required.
A number that doesn't exist: 800, 900 or 950 on gold usually indicates silver or platinum marks copied onto the wrong metal.
Stamp and appearance disagreeing. A "999" mark on a piece that is hard, springy and pale is a contradiction: 24K gold is soft and deeply yellow.

What If There Is No Hallmark At All?

Plenty of genuine gold is unmarked: antique and handmade pieces predating mandatory stamping, items resized or repaired in a way that removed the mark, gold from markets without a hallmarking regime, and natural nuggets, which are never stamped because they are not manufactured.

Absence of a mark is not proof of a fake. It just means you have to fall back on physical testing: weight against size, a magnet, and ultimately acid or XRF. Our eight ways to check covers the full sequence.

Decode Any Hallmark From a Photo

Photograph the stamp and Gold Identifier explains what it means, what purity it claims and where that mark is used. Free on iPhone and Android.

Frequently Asked Questions

What does 750 mean on gold?

750 means 75% pure gold, which is 18 karat. The remaining 25% is alloy metals: typically copper and silver for yellow gold, palladium or nickel for white gold, and a higher proportion of copper for rose gold. It is the standard for European and luxury fine jewelry.

Is 375 real gold?

Yes. 375 means 37.5% gold, which is 9 karat, and it is legally sellable as gold in the UK, Ireland and Australia. It is genuine gold alloy but with a low precious-metal content, so its melt value is much lower than 18K or 22K of the same weight.

What is the difference between a hallmark and a maker's mark?

A hallmark records purity and, in regulated markets, is applied by an independent assay office after testing. A maker's mark or sponsor's mark identifies who produced or submitted the item. A complete UK hallmark includes both, plus an assay office town mark.

Can hallmarks be faked?

Yes, and they regularly are on counterfeit jewelry and bars. Genuine stamps are crisply and evenly struck. Forgeries tend to look shallow, smeared or hand-scratched, and often use a mark that doesn't fit the piece's style or market of origin.

Where is the hallmark on a gold chain?

Usually on the clasp, on a small flat tag soldered near the clasp, or on one of the end links. On rings it is inside the shank; on pendants it is often on the bail or the reverse; on earrings it is on the post or butterfly back.