Gold stamps tell you the purity of the metal. Karat marks like 10K, 14K and 18K state the gold content in 24ths, and number marks like 417, 585 and 750 state it in parts per thousand, so 585 and 14K mean the same thing. Marks like GF, GP and HGE mean the piece is only coated with gold. Here's every common stamp, what it means, and where to find it.
Where to Find the Stamp
- Rings — inside the band, usually at the bottom.
- Chains and bracelets — on the clasp or on the small tag or ring next to it.
- Earrings — on the post, or inside a hoop near the hinge.
- Pendants — on the bail (the loop the chain runs through) or on the back.
Stamps are tiny and often worn, so a magnifier or jeweler's loupe helps a lot.
Gold Purity Stamps
| Karat stamp | Number stamp | Pure gold content |
|---|---|---|
| 9K | 375 | 37.5% (common in the UK; too low to be sold as gold in the U.S.) |
| 10K | 417 | 41.7% |
| 14K | 583 or 585 | 58.3% to 58.5% |
| 18K | 750 | 75% |
| 21K | 875 | 87.5% (common in Middle Eastern jewelry) |
| 22K | 916 | 91.6% (common in Indian and Middle Eastern jewelry) |
| 24K | 999 | 99.9% |
You'll also see KT instead of K (14KT means the same as 14K). Older American 14K pieces are often stamped 583, the exact figure for 14 parts in 24, while 585 is the European convention, rounded up so the gold is never under the stated karat.
What Does KP or "Plumb" Mean?
A P after the karat, as in 10KP or 14KP, stands for plumb. It means the gold content meets the full stated karat, with no allowance for being slightly under. It's still regular 10K or 14K gold.
Stamps That Mean It Isn't Solid Gold
- GP, GEP or GE — gold plated or gold electroplated: a very thin layer of gold over a base metal. Worth almost nothing for its gold.
- HGE or HGP — heavy gold electroplate: a thicker plating, but still plated.
- GF, or marks like 1/20 12K GF — gold filled: a much thicker layer of karat gold bonded to a base metal, typically 1/20 of the total weight. It has some gold value, but far less than solid gold.
- RGP — rolled gold plate: similar to gold filled, with a thinner gold layer.
- Vermeil — gold plating over sterling silver.
Watch for combinations. A piece stamped 14K HGE or 18K GP is plated with gold of that color, not made of 14K or 18K gold.
Silver and Platinum Stamps
- 925, STER or Sterling — sterling silver, 92.5% silver.
- 800, 830 or 900 — silver of 80%, 83% or 90% purity, common on European and older pieces.
- 999 on silver — fine silver, 99.9% pure.
- PT950, PLAT or 950 PLAT — platinum, 95% pure. PT900 is 90%.
- PD950 — palladium.
For what silver pieces are worth, see is silver jewelry worth selling?
Other Marks You Might See
Next to the purity stamp you'll often find a maker's mark or trademark. Italian gold commonly carries a small star with a number and a province code, which identifies the registered maker. Diamond jewelry may be stamped with the total diamond weight, like 1/2 CT TW, and some pieces carry a country of origin such as Italy or Turkey.
A Stamp Is a Claim, Not Proof
A stamp tells you what the maker claimed, and that's all. Stamps wear away on old pieces, clasps get replaced with ones of a different karat, and counterfeit jewelry is sometimes stamped 14K on purpose. On the other hand, real gold can have no stamp at all, especially older, handmade or resized pieces where the stamp was cut out of a ring band. That's why every piece should be tested before it's priced. Here's how jewelry gets tested.
What the Stamp Means for Value
Gold jewelry is priced on its pure gold content: the weight of the piece multiplied by its purity. At the same weight, an 18K piece contains about 1.8 times the gold of a 10K piece. Our live gold price per gram calculator shows what that's worth today, and 10K vs. 14K vs. 18K gold compares the karats in more detail.
Frequently Asked Questions
What does 585 mean on gold?
585 means the piece is 58.5% pure gold, which is 14 karat. It is the European way of writing 14K and is common on Italian and other imported jewelry.
What does 750 mean on gold?
750 means the piece is 75% pure gold, which is 18 karat.
What does 10KP mean on jewelry?
10KP means 10 karat plumb. The gold content meets the full 10 karat stated, with no allowance for being slightly under. It is still 10K gold.
Is gold filled jewelry worth anything?
Gold filled jewelry has a real layer of karat gold, typically about 1/20 of its total weight, so it has some scrap value, but far less than solid gold of the same size. Gold plated jewelry has almost none.
Can real gold have no stamp?
Yes. Older, handmade and resized pieces sometimes have no stamp or a worn one. An unstamped piece needs to be tested to confirm what it is.