How to tell if gold is real: marks and simple checks

Solid gold, gold filled and gold plate can look the same in a jewellery box. The difference sits in tiny stamps inside a ring, on a clasp or on the back of a pendant, and in how the surface has worn over the years. Here is how to read them.

Start with the marks

Use a bright light and a magnifier. Look inside ring bands, on clasps and jump rings, on the back of brooches and pendants, and on the case back of a watch.

Karat marks (common in the US and on older pieces)

• 10K, 14K, 18K, 22K, 24K. The number is parts of gold out of 24. 14K is 58.3% gold, 18K is 75%, 24K is pure gold.
• “KP” after the number (14KP) means “karat plumb”, a promise that the gold content is exactly as stated, not slightly under.

Fineness marks (parts per thousand, common in Europe and on modern pieces)

• 375 is 9 karat, very common on British jewellery.
• 417 is 10 karat, 585 is 14 karat, 750 is 18 karat, 916 is 22 karat, 999 is 24 karat.

British gold British gold carries a set of hallmarks: the fineness number in a shaped shield, a town mark (an anchor for Birmingham, a leopard’s head for London, a rose for Sheffield, a castle for Edinburgh) and often a date letter. Before 1975, British gold of 18 and 22 karat showed a crown next to the number. A full, crisp set of marks is a strong sign the piece was tested at an assay office.

A maker’s mark (initials or a name) next to the gold mark helps date the piece and can add value on its own.

Marks that mean gold filled or plated

• GF, 1/20 12K GF, 1/10 14K GF: gold filled. A real gold layer bonded to base metal, thicker than plate.
• RGP, “rolled gold”, “rolled gold plate”: a thinner bonded layer than gold filled.
• GP, GEP, “gold plated”, “gold electroplate”: a very thin plated layer.
• HGE: heavy gold electroplate, still a thin layer.
• “Vermeil” or 925 on a gold-coloured piece: sterling silver with a gold layer. The silver is real; the gold is only on the surface.
• “Gold tone” or no mark on a cheap modern piece: usually no gold at all.

A number with letters after it, such as 14K GF, describes the gold in the layer, not the whole piece. Read every character of the mark.

A few safe checks at home

1. The magnet test. Gold is not magnetic. If a strong magnet grabs a ring or chain, it is not solid gold, though a steel clasp or spring can pull on its own, so test the main body. If the magnet ignores it, that does not prove gold.
2. Look for wear. Plate and gold filled wear through on high points: the inside of a ring, the edges of a chain link, the corners of a cufflink. A patch of grey, pink or brassy metal underneath means a layer, not solid gold.
3. Check the colour against the mark. A deep yellow 9K piece, or a pale, greenish “22K” one, is a reason to look closer. Lower karats are paler because they hold more silver and copper.
4. Skin marks. A ring that leaves a green or black line on the finger usually has copper or other base metals near the surface. It is a hint, not proof.

Skip scratch, bite, bleach and vinegar tests at home. They damage the surface and the value, and they are not reliable.

When to ask a professional

If the marks and checks suggest solid gold, a jeweller can confirm it with an acid test on a hidden spot or a non-destructive XRF reading, and weigh it for a scrap price. For a signed maker, an antique piece or anything set with stones, get an appraisal before you sell for scrap, because the design can be worth far more than the metal.

You can also photograph the whole piece and a close-up of the marks and let Gavel identify it. Gavel reads the marks as part of its identification, and Gavel Pro looks up what similar pieces sold for, with its sources. Treat it as a strong first opinion and confirm a valuable piece with a test.

More on reading marks: how to tell if silver is real and how to tell if an antique is valuable.