Quick answerLook for a karat stamp (10K, 14K, 18K, or 417, 585, 750), and make sure there are no plating marks such as GF, GP, HGE or RGP. Real gold isn't magnetic. For certainty, have it tested with acid or XRF, which is what buyers do before they pay.
1. Read the stamp
| Stamp | Means | Gold content |
|---|---|---|
| 24K / 999 | Pure gold | 99.9% |
| 22K / 916 | Common in coins and South Asian jewelry | 91.7% |
| 18K / 750 | Fine jewelry | 75.0% |
| 14K / 585 | Most common in US jewelry | 58.3% |
| 10K / 417 | Lowest karat sold as "gold" in the US | 41.7% |
| 9K / 375 | Common in UK jewelry | 37.5% |
The FTC's Jewelry Guides say gold under 10 karat shouldn't be marketed as "gold" in the US1. MailGoldOnline publishes a similar karat-to-fineness table2.
2. Watch for plating marks
These marks mean the piece isn't solid gold:
- GF or "1/20 12K GF": gold filled. Under FTC guidance, the gold layer must be at least 1/20 of the item's total metal weight1.
- GP / GEP: gold plated or electroplated, a very thin layer.
- HGE: heavy gold electroplate. RGP: rolled gold plate.
- 925 with gold color: gold-plated sterling silver, which is worth silver value.
Plated and filled items are worth little as scrap. Some buyers won't take them at all.
3. Simple home checks
- Magnet: gold isn't magnetic, so a strong pull means base metal. A weak pull can come from a steel clasp spring. Passing the magnet test doesn't prove it's gold.
- Wear points: look at edges, clasps and the bottom of ring bands. A different color showing through usually means worn plating.
- Skip the bite and scratch tests. They damage the piece and prove little.
4. How buyers test it
Kitco says it scratch-tests scrap on a touchstone with acid, and can melt or assay material if that's inconclusive. It also notes that its acid tests are accurate only up to 18K3. Many buyers now use XRF (X-ray fluorescence), which reads the metal content without damaging the piece. Offramp, for example, says it runs XRF on video4. DD Pawn Loans says it opens every mail-in package on camera5. Ask any buyer how it tests, and ask for the karat results item by item.
Common questions
Does a 14K stamp guarantee it is real?
No. A stamp is a strong clue, but stamps can be faked or wrong. Buyers test before they pay, so get tested if the value matters.
Is 10K gold real gold?
Yes. 10K is 41.7% gold and is the lowest karat that can be marketed as gold in the US. Anything below 10K cannot be called gold under the FTC Jewelry Guides.