How to tell if gold is real

The surest signs are marks and paperwork, not tricks: a karat stamp on the piece, a karat and a weight written on an invoice, and a shop that will stand behind both. Home tests are weak, and some of them damage the piece.

Start with the stamp

Solid gold is stamped with its fineness: 999 for 24K, 875 for 21K, 750 for 18K and 585 for 14K. Look inside a band, on the clasp, or on the small tag at the end of a chain. A stamp shows what the maker states. It does not prove it on its own, which is why the invoice matters just as much.

Marks such as GP or GEP mean the piece is plated, not solid gold. Plating is a thin layer over another metal, and it wears through at the edges and the high points first.

Keep the invoice

A proper invoice names the karat, the net weight, the rate and the making charge. It is also what you need later: our returns and buy-back terms ask for proof of purchase.

Solid, plated and filled

Solid gold is gold all the way through. Plated pieces carry a very thin layer of gold over another metal, and gold-filled pieces a thicker one. Both can look right when new, and both cost far less than solid gold of the same size. A piece described only as "gold colour" or "gold tone" is not gold.

Check the weight against the price

Gold is dense, so a solid gold piece usually feels heavier than a plated or brass piece of the same size. Weight is also the easiest number to check against the price. The price should be roughly (rate + making charge) × weight, as the pricing guide sets out, and today's rate is on the rate page. A price far below that for the weight claimed deserves a question before it deserves a purchase.

Tests that work, and tests that don't

A magnet can rule some fakes out. Gold is not magnetic, so a piece that sticks to a magnet is not solid gold. It cannot rule a piece in, because many fakes are not magnetic either. Acid and scratch tests can mark or damage a piece and are best left to a jeweller. If you want certainty, ask a jeweller to test the karat with an electronic tester: it takes a minute and leaves the piece untouched.

Signs to be careful

• No invoice, or one that leaves out the karat or the weight.
• A stamp that is missing, blurred, or does not match what you were told.
• Colour wearing off at the edges, or a different metal showing underneath.
• A price well below the day's rate for the weight claimed.
• Pressure to decide quickly, or a refusal to weigh the piece in front of you.

What we do

Every piece we sell is weighed and stamped, and its page shows the karat and the weight it is priced from. Wherever you buy, ask for the karat, the weight and the invoice.