The tiny stamp inside your ring or on the clasp of your bracelet is one of the most important numbers in gold buying — and most people have no idea how to read it. Understanding gold hallmarks before you walk into a buyer's office gives you immediate leverage and helps you confirm you're getting a fair offer.
What Is a Gold Hallmark?
A hallmark is an official mark stamped into precious metal jewelry or objects to certify their purity. In the United States, gold jewelry sold after 1906 must carry a quality mark identifying its karat purity. These marks are tiny — sometimes only 1–2mm — but they're legally required and carry significant value information.
US Karat Marks: What They Mean
- 24K or 999 — 99.9% pure gold. Bullion bars, coins, and some high-end Asian jewelry. Softest, most valuable by weight.
- 22K or 916 — 91.6% pure. Common in British hallmarked jewelry and older coins.
- 18K or 750 — 75% pure. Fine European and luxury jewelry (Cartier, Tiffany, Bulgari). High value.
- 14K or 585 — 58.5% pure. The most common in American jewelry. Strong value.
- 10K or 417 — 41.7% pure. The minimum legal karat in the US. Still valuable, just less so.
- GF, GP, or GE — Gold Filled, Gold Plated, or Gold Electroplated. These are NOT solid gold and have little to no precious metal value.
- HGE — Heavy Gold Electroplate. Also not solid gold, despite the heavy description.
If your piece says 'GF', 'GP', or 'GE' anywhere — it is not solid gold. Don't be misled by shiny appearance. A reputable buyer will tell you this upfront.
European and International Hallmarks
Much of the estate jewelry seen in Connecticut was made in Europe or imported decades ago. European hallmarks use a fineness system (parts per thousand) instead of karats:
- 999 — 24K equivalent
- 958 — 23K (sometimes seen in Portuguese jewelry)
- 916 — 22K
- 750 — 18K
- 585 — 14K
- 375 — 9K (common in British and Irish jewelry)
Maker's Marks and Assay Office Marks
Beyond purity, gold jewelry often carries additional marks: a maker's mark (the manufacturer or jeweler's unique symbol), a date letter (in British hallmarked pieces, identifying the year of manufacture), and an assay office mark (the testing facility that certified the piece). These don't directly affect the gold's melt value but can dramatically increase the piece's collectible value — especially for signed pieces from known makers like Tiffany, Cartier, or Van Cleef & Arpels.
What If There's No Hallmark?
Older American jewelry (pre-1906) and some handmade or imported pieces may lack hallmarks. This doesn't mean they aren't gold — a professional buyer will use an electronic tester or acid test to determine purity. Never assume an unmarked piece is worthless or fake without a proper test.
How to Find the Hallmark on Your Piece
- Rings: inside the band
- Necklaces and bracelets: on the clasp, or on a small attached tag
- Earrings: on the post or the back of the setting
- Brooches: on the back, often near the clasp mechanism
- Watches: on the case back, or inside the case
Use a magnifying glass or jeweler's loupe — the stamps are very small and often worn. Good lighting is essential.
Not sure what your hallmarks mean? Bring your pieces to Gold Buyers Connecticut for a free expert reading and appraisal. No obligation to sell.