That tiny row of numbers and letters stamped inside your ring or on your chain's clasp isn't decoration — it's a code that tells you exactly what your jewelry is made of. Learning to read gold hallmarks and stamps lets you identify solid gold, spot plated fakes, and estimate your payout before you ever talk to a buyer. Here's how to decode them.
Where to find the hallmark
Marks are small, so grab a magnifying glass or use your phone's camera zoom in good light. The usual spots:
- Rings — inside the band
- Chains & bracelets — on the clasp or a small oval tag near the clasp
- Earrings — on the post or the back
- Pendants & charms — on the back or the bail (loop)
Karat stamps vs. number stamps
Gold purity is marked one of two ways: the American karat system (with a K) or the European millesimal system (a three-digit number showing parts per thousand). They mean the same thing.
| Karat stamp | Number stamp | Purity |
|---|---|---|
| 10K | 417 or 416 | 41.7% |
| 14K | 585 or 583 | 58.5% |
| 18K | 750 | 75.0% |
| 22K | 916 | 91.6% |
| 24K | 999 | 99.9% |
To turn a purity mark into a dollar figure, see how the math works in our guide on 10K vs 14K vs 18K vs 24K gold.
Can't read your stamp? Bring it in and we'll test it free.
Call (909) 737-2467The warning letters: GP, GF, GE, HGE
This is the most important part for anyone thinking about selling. If your karat or number stamp has extra letters attached, the piece is not solid gold:
- GP — Gold Plated. A microscopic layer of gold over base metal.
- GF — Gold Filled. A thicker gold layer than plating, but still mostly base metal (often stamped like "14K GF" or "1/20 14K GF").
- GE / HGE — Gold Electroplated / Heavy Gold Electroplate. Still just plating.
- RGP — Rolled Gold Plate. Another thin-layer method.
These have little to no scrap value. A clean "14K" or "585" with no trailing letters is what indicates solid gold.
Other marks you might see
Beyond purity, you may spot a maker's mark (a logo or initials identifying the manufacturer), a country-of-origin stamp, or designer marks like the Italian "750" with a small oval maker's stamp. On sterling silver you'll see 925 instead — that's silver, not gold, and our guide on how to sell silver covers that. Occasionally a genuine piece has no stamp at all (older or handmade jewelry), which is exactly why a professional test matters.
A stamp isn't a guarantee — verify it
Counterfeiters can and do fake stamps, and worn marks can be hard to read. A hallmark is a strong starting clue, but the only way to be sure is to test the metal. Our guide on how to tell if your gold is real covers seven at-home checks, and any reputable buyer will run a free acid or electronic test in seconds.
Turn your stamps into cash
Once you've identified your solid-gold pieces, sort them by karat and get a real quote based on the live spot price. At SoCal Cash for Gold we read your hallmarks, test everything for free while you watch, and pay up to 95% of live spot — same-day cash, Zelle, or Venmo. Visit our Montclair counter or use our insured mail-in service from anywhere.
Bring Unmarked or Confusing Pieces In for Free Testing
Some of the best gold has no readable stamp at all — worn-down marks, older or handmade jewelry, or a piece where you can't tell if that's a "585" or a "GF." Instead of guessing under a magnifying glass, bring it to our counter at 4994 Holt Blvd in Montclair. We'll read the hallmark for you and, when there isn't one, run a free professional acid, electronic, or XRF test that confirms both the metal and its exact karat in seconds — no obligation to sell.
Neighbors from Claremont, Upland, Pomona, Chino, and Fontana bring us mystery pieces all the time, and being licensed and bonded means our read on your stamps is one you can trust. Once we've confirmed what you've got, we price it on live spot and pay up to 95% same-day in cash, Zelle, or Venmo. If you're closer to us than downtown, our Montclair gold buyer page has hours and directions — just bring whatever's puzzling you.