The short answer
Start by reading the stamps, then use safe, non-destructive checks such as a magnet and a close look at wear. These can rule pieces out or raise questions, but they cannot prove a piece is solid gold. Stamps can be faked, and some fakes pass simple home tests. For anything that may be valuable, ask a reputable jeweler, assayer or appraiser to test it; many can use non-destructive methods.
1. Read the stamps
Look on clasps, the inside of rings, earring posts, pendant bails and the backs of pieces. A loupe or your phone's camera zoom helps.
- Karat marks: common US marks include 10K, 14K, 18K and 22K, sometimes written "KT".
- Fineness numbers: numbers such as 417, 585, 750, 916 and 999 show gold content in parts per thousand. For example, 585 corresponds to 14 karat and 750 to 18 karat.
- Plating and filled marks: GP (gold plated), GEP (gold electroplated), HGE (heavy gold electroplate), RGP (rolled gold plate) and GF (gold filled) mean the piece is not solid gold. Marks like "1/20 14K GF" describe a gold layer over another metal.
- Vermeil: usually gold over sterling silver, often marked 925.
- Maker's marks and hallmarks: a maker's mark or, in some countries, official assay hallmarks can help identify and date a piece.
A karat stamp is a claim, not proof. Counterfeit pieces can carry stamps, and some genuine older pieces were never stamped or have worn stamps.
2. Try a magnet
Gold itself is not magnetic. If a strong magnet pulls the piece clearly, it is probably not solid gold, or it contains a magnetic part such as a steel spring in a clasp. A piece that ignores the magnet is not proven real, because many non-magnetic metals are used in fakes.
3. Look for wear and discoloration
Check high-wear areas such as clasp edges, ring shanks and chain links. If a different colored metal shows through where the surface has rubbed, the piece is likely plated or filled. Green or black marks on skin, or green spots on the piece, can also suggest base metal, though some lower-karat gold alloys can discolor skin too.
4. Consider the color and weight
Gold is dense, so solid pieces often feel heavier than you expect for their size. Color varies with karat and alloy: yellow, white and rose gold all exist, and white gold is often rhodium plated. Color and heft are useful clues, but they are easy to misjudge without experience. A jeweler can measure density accurately as part of testing.
5. Avoid tests that damage the piece
Home acid kits, scratching a piece on a ceramic plate, biting it or trying a flame can all mark or damage jewelry and may lower its value. They can also mislead on plated pieces, because only the surface layer is tested. Leave these methods to professionals, who know how to test discreetly or use non-destructive equipment such as an X-ray fluorescence analyzer.
6. Coins and bars
Gold bullion and coins are counterfeited, sometimes with a tungsten core that matches gold's weight closely. Compare the weight, diameter and thickness with the mint's or refiner's published specifications, and check design details against genuine examples. Packaged bars often come in an assay card or certificate; these are copied too. Buy and sell through established dealers, and ask them to verify anything you are unsure about.
7. Watch for seller red flags
- A price close to, or below, the scrap value of the stated gold content.
- Vague descriptions such as "gold tone", "gold color" or "gold finish" next to a karat mention.
- No close-up photos of the stamps.
- Refusal to allow testing by a jeweler before the sale is final.
Where WorthAI fits
WorthAI can help you identify the likely type of piece from a photo and see what similar items sell for, with the listings behind the estimate. The estimate assumes the stamps and materials are genuine. WorthAI cannot test metal and is not an authentication service, so have a jeweler or appraiser confirm gold content before you rely on it.
Frequently asked questions
Does a 14K stamp prove a piece is real gold?
No. Stamps are a claim made by the maker, and fakes can carry them. Combine the stamp with other checks, and ask a jeweler to test anything valuable.
Is real gold magnetic?
No. Solid gold is not magnetic, so a strong pull suggests another metal. Passing the magnet test does not prove a piece is gold, though.
What does GF mean on jewelry?
GF stands for gold filled: a layer of gold bonded to a base metal. It is not solid gold, although it usually has more gold than plated pieces.
Can WorthAI test whether my gold is real?
No. WorthAI identifies the likely item and estimates value assuming it is genuine. A jeweler or appraiser needs to test the metal.