Gold Hallmark Guide and Lookup Tool
Look up gold stamps to find karat, purity and live value.Type the stamp on your jewellery to see the karat, purity and live value.
GP plated · GEP electroplated · HGE heavy electroplate · GF gold filled.
A fraction next to the karat mark, such as 1/20 12K, means gold filled. Scrap buyers rarely pay for it.
Every Gold Fineness Mark
| Stamp | Karat | Purity | Common origin | Per gram | Per dwt |
|---|---|---|---|---|---|
| 333 | 8K | 33.3% | Germany, older European jewellery | $44.73 | $69.56 |
| 375 | 9K | 37.5% | UK, Ireland, Australia | $50.37 | $78.33 |
| 417 | 10K | 41.7% | United States, Canada | $56.01 | $87.10 |
| 500 | 12K | 50.0% | Rare, older European pieces | $67.16 | $104.44 |
| 585 | 14K | 58.5% | US, Germany, Eastern Europe | $78.57 | $122.19 |
| 625 | 15K | 62.5% | Antique British jewellery | $83.95 | $130.55 |
| 750 | 18K | 75.0% | Italy, France, luxury jewellery | $100.73 | $156.66 |
| 833 | 20K | 83.3% | Portugal, Middle East | $111.88 | $174.00 |
| 875 | 21K | 87.5% | Gulf states, Egypt | $117.52 | $182.77 |
| 916 | 22K | 91.6% | India, Pakistan, Middle East | $123.03 | $191.33 |
| 958 | 23K | 95.8% | Thailand, Southeast Asia | $128.67 | $200.11 |
| 990 | 23.75K | 99.0% | China, Hong Kong | $132.97 | $206.79 |
| 999 | 24K | 99.9% | Bullion bars and coins | $134.18 | $208.67 |
Karat marks
The American and British convention: a number out of 24 followed by K, KT or CT. 14K means 14 parts gold in 24 parts metal. Anything above 24K is a marketing claim, not a purity.
Millesimal fineness
The European convention: parts per thousand. 750 means 750/1000 = 75% gold, the same metal as 18K. Continental jewellery almost always carries the three-digit form.
Plated and filled marks
GP gold plated · GEP gold electroplated · HGE heavy gold electroplate · GF gold filled · RGP rolled gold plate.
Gold filled carries a fraction: 1/20 12K means a 12K layer that is 5% of the item's weight. Scrap buyers rarely pay for it.
Telling solid from plated
Look for wear at edges and clasps where the base metal shows through, check for a fraction next to the karat mark, and weigh it. Plated pieces feel light for their size. A magnet test rules out steel cores; an acid or XRF test settles it.