How to Read Gold Hallmarks and Stamps
How-To Guides
Learning how to read gold hallmarks and stamps is one of the most useful skills you can pick up as a jewelry owner. Those tiny numbers and symbols hidden on a clasp or the inside of a ring tell you exactly how much real gold you own, and once you know the code, you can read any piece in seconds.
What Is a Gold Hallmark?
A hallmark (sometimes called a stamp, maker's mark, or purity mark) is a small impression stamped into precious metal to certify its fineness. In some countries hallmarking is legally required and tightly regulated; in others, like the United States, manufacturers self-stamp their pieces. Either way, the mark is your first and best clue to what a piece is actually made of.
Grab a jeweler's loupe or even your phone's macro camera and good light. The marks are usually tiny, so magnification makes all the difference. Common hiding spots are the inner band of a ring, the clasp or jump ring of a necklace or bracelet, and the post or back of an earring.
The Two Hallmark Systems You'll See Most
Karat Marks (Common in the USA)
American gold is usually marked in karats out of 24. So "14K" means 14 parts gold out of 24, or about 58.3% pure. You may also see "14KT" or "14KP" (the P stands for "plumb," meaning it is exactly 14K, not slightly under).
Fineness Marks (Common in Europe and Modern Pieces)
Fineness is expressed in parts per thousand. A "585" stamp means 585 parts gold out of 1,000, which is the same as 14K. Once you memorize a few of these, the conversions become second nature.
Gold Hallmark and Fineness Reference Chart
| Karat Mark | Fineness Mark | Gold Purity |
|---|---|---|
| 24K | 999 / 9999 | 99.9% pure |
| 22K | 916 | 91.6% pure |
| 18K | 750 | 75.0% pure |
| 14K | 585 | 58.3% pure |
| 10K | 417 | 41.7% pure |
| 9K | 375 | 37.5% pure |
In the U.S., 10K is the legal minimum to be sold as "gold," which is why you will rarely see anything stamped below 417.
Marks That Mean It Is NOT Solid Gold
Some stamps look reassuring but actually warn you the piece is only coated. Watch for these:
- GP – Gold Plated (a thin electroplated layer)
- GF – Gold Filled (a thicker bonded layer, often written like "14K GF")
- GEP – Gold Electroplated
- RGP – Rolled Gold Plate
- HGE – Heavy Gold Electroplate
- Vermeil – Sterling silver with a gold layer on top
If you see a number like 585 followed by GF, the piece is gold filled, not solid 14K. This is one of the most common mix-ups, so look carefully at the whole stamp, not just the number.
Maker's Marks and Country Marks
Alongside the purity stamp you may find a maker's mark (the initials or logo of the manufacturer or designer) and, in regulated markets, an assay office symbol. British pieces, for example, carry a lion passant for sterling silver and a separate town mark and date letter. These extra marks can help you date a piece and confirm authenticity, which matters a lot for vintage and estate jewelry.
What to Do Once You've Read the Mark
Knowing the karat is the first step to knowing the value. The next step is to weigh your jewelry at home and then run the numbers. From there you can calculate the gold melt value or jump straight to our scrap gold calculator for an instant estimate. For a deeper dive into purity standards across metals, the guide on understanding precious metal purity is a great companion read.
How BigStash Helps
When you log a piece in BigStash.app, you can record its exact hallmark and karat alongside photos of the stamp itself. That way the details are saved forever, and the app can estimate melt value automatically as gold prices move.
Frequently Asked Questions
What does 585 mean on gold?
585 is a fineness mark meaning the metal is 585 parts gold per 1,000, which equals 14K or 58.3% pure gold.
My ring has no hallmark. Is it fake?
Not necessarily. Older pieces, handmade items, and jewelry that has been resized may have lost or never had a stamp. The safest move is an acid test or XRF test from a jeweler to confirm the karat.
Does a hallmark guarantee the gold is real?
A hallmark is strong evidence but not an absolute guarantee, since stamps can be faked. If a piece is high value, confirm with an at-home or professional gold test.