Gold Hallmark Stamps: What 585, 750, and 417 Actually Mean
That tiny number stamped on the inside of your ring or the clasp of your chain tells you exactly how much gold your piece contains. Once you know how to read it, you can instantly calculate what any piece is worth. Here is the complete guide.
What Is a Hallmark?
A hallmark is an official mark stamped onto precious metal items to certify their purity. In the US, the FTC requires that any piece sold as gold be accurately marked with its karat or fineness. You will typically find the stamp on the inner band of rings, the jump ring or clasp of necklaces, and the post or clasp of earrings.
The Two Systems: Karat vs. Millesimal Fineness
The US uses the karat system (10K, 14K, 18K). Much of Europe and the international gold trade uses millesimal fineness — a three-digit number representing parts per thousand. Both systems appear on jewelry sold in the US, especially imported pieces.
Complete Hallmark Reference Table
Here is every common gold hallmark with its purity and today’s price per gram:
| Stamp | Karat | Gold Purity | Price Per Gram Today | Common Use |
|---|---|---|---|---|
| 417 | 10K | 41.7% | ~$59.55 | Budget jewelry, children’s pieces, US market |
| 585 | 14K | 58.5% | ~$83.37 | Most US engagement rings, chains, everyday jewelry |
| 750 | 18K | 75.0% | ~$107.20 | European fine jewelry, luxury pieces |
| 916 | 22K | 91.6% | ~$131.02 | Indian gold jewelry, some coins |
| 999 | 24K | 99.9% | ~$142.93 | Investment coins, bars, bullion |
What If There Is No Stamp?
Older pieces, handmade jewelry, some imported items, and gold from certain countries may lack a hallmark. Absence of a stamp does not mean it is not gold — it just means you cannot verify purity visually. A jeweler can test it with an acid test (inexpensive, about $5–$10) or an XRF (X-ray fluorescence) analyzer (non-destructive, very accurate).
Stamps That Mean It Is NOT Solid Gold
Watch out for these markings — they indicate plated or filled gold, not solid gold:
- GP or GEP — Gold Plated / Gold Electroplated. A thin layer of gold over base metal. Melt value is essentially zero.
- GF — Gold Filled. More gold than plating, but still a thin layer bonded to base metal. Low melt value.
- RGP — Rolled Gold Plate. Similar to gold filled. Not solid gold.
- HGE — Heavy Gold Electroplate. Thicker plating, but still not solid gold.
Only pieces stamped 10K/417 through 24K/999 are solid gold and have meaningful melt value. Use our gold calculator to find out what your solid gold piece is worth today.
Why This Matters When Using a Gold Calculator
When you enter data into any gold calculator — including ours — the karat input determines the purity multiplier. If you enter 14K for a piece that is actually 10K, the calculator will overestimate the melt value by about 40%. Read the stamp carefully before calculating.