How to Read Gold Hallmarks and Stamps

Hallmarks are small, so use a loupe or your phone's camera zoom. On rings look inside the band; on chains check the clasp and the small tag next to it; on earrings check the post or butterfly; on bracelets the clasp or the underside of a link; on watches the inside of the case back.

The most reliable part of any mark is the fineness number: 375 (9k), 417 (10k), 585 (14k), 750 (18k), 875 (21k), 916 (22k), 990 or 999 (24k). Older American jewelry may show 583 for 14k and 417 or 416 for 10k. Karat marks such as 14K, 14KT or 18ct mean the same thing.

These letters are added after the karat and are the single most common reason a seller is disappointed.

• GP or GEP — gold plated or gold electroplated. A microscopic layer; scrap value close to zero.
• HGE — heavy gold electroplate. Slightly thicker, still almost no gold.
• RGP — rolled gold plate. A thin bonded layer.
• GF or 1/20 12K GF — gold filled. About 5% gold by weight; some refiners buy it at a small fraction of solid value.
• Vermeil — gold-plated sterling silver. Worth its silver content.
• KP — karat plumb. The opposite: it guarantees the piece meets its karat exactly.

UK hallmarking is compulsory for gold items over 1 gram. A full mark has a sponsor's (maker's) mark, a fineness mark such as 375 or 750, and an assay office mark — a leopard's head for London, an anchor for Birmingham, a rose for Sheffield and a castle for Edinburgh. Many pieces also carry a date letter, which lets you date them to the year. An optional crown symbol for gold may appear alongside.

Countries in the International Hallmarking Convention use a Common Control Mark: a pair of scales with the fineness inside. Switzerland adds a St. Bernard's head on gold watch cases. France uses an eagle's head for 18k. Italian jewelry shows the fineness, a five-pointed star, a number and a province code (AR for Arezzo, VI for Vicenza) identifying the registered maker.

Since 2021 most gold jewelry sold in India must carry a BIS hallmark with three parts: the BIS triangle logo, the purity grade (for example 22K916 or 18K750) and a six-character alphanumeric HUID code. You can verify the HUID in the official BIS Care app, which shows the purity, item type and the jeweler who registered it. Hallmarked jewelry gets better exchange and resale rates because the buyer does not need to rely on their own test.

The US has no official assay office. Federal rules require that a karat mark is accurate within tolerance and that it is accompanied by a registered trademark of the maker, so a mark like 14K plus a maker's logo is normal. In the Gulf and Egypt, pieces carry the fineness (often 875 for 21k or 916 for 22k), sometimes written in Arabic numerals, alongside a government assay mark.

Absence of a stamp does not mean an item is fake — very old, hand-made or resized pieces often lose or never had marks. Equally, a stamp can be applied to base metal by a counterfeiter. If in doubt, ask a dealer for an XRF or acid test, which is usually free. A magnet test is a quick first check: gold is not magnetic, so a strong pull means a steel core, though a non-magnetic result proves nothing on its own.

Once you know the fineness, weigh the item and use the karat price pages or the scrap gold calculator to find what it is worth today.