Decode Hallmarks Instantly
Type any gold stamp or hallmark to verify karat purity, identify authenticity markers, and check if your gold is genuine. Supports 500+ international hallmarks.
Type any stamp from your jewelry: numbers, karat marks, or purity codes
Hallmark Analysis
Karat Reference Guide
Why Use This Purity Checker
Hallmark Decoder
Type any stamp to decode its meaning instantly.
International Standards
USA, UK, EU, India, China, Middle East marks.
Purity Verification
Verify claimed purity matches known standards.
Visual Guide
Compare stamps against our reference cards.
Common Gold Hallmarks Decoded
| Hallmark | Karat | Purity % | Common In | Notes |
|---|---|---|---|---|
| 999 / 999.9 | 24K | 99.9% | Bullion, bars | Too soft for jewelry |
| 916 | 22K | 91.6% | India, Middle East | Traditional jewelry |
| 750 | 18K | 75.0% | Europe, luxury | Cartier, Tiffany standard |
| 585 | 14K | 58.5% | USA, engagement | Most common US purity |
| 417 | 10K | 41.7% | USA, budget | Minimum US legal karat |
| 375 | 9K | 37.5% | UK, Australia | Minimum UK legal karat |
| GP / GEP | — | Minimal | Worldwide | NOT solid gold |
| GF | — | 5-10% | USA, vintage | Gold filled, not solid |
Frequently Asked Questions
Gold hallmarks certify purity. 750 = 75% pure gold (18K). Karat marks like 18K = 18 parts gold out of 24. Marks may include maker, assay office, and date depending on country.
Yes. Warning signs: blurry stamps, wrong fonts, missing maker's marks, unrealistic prices. Gold-plated items may be illegally stamped. Professional testing recommended for high-value items.
GP = Gold Plated (thin layer over base metal). GF = Gold Filled (thicker bonded layer). Neither is solid gold. Both have minimal melt value.
US: 10K (41.7%). UK: 9K (37.5%). Below these thresholds, items cannot legally be sold as gold jewelry. Some countries like France require 18K minimum.