417, 585, 750, 925 — and the Stamps That Only Look Like Gold
417, 585, 750, 925 — and the Stamps That Only Look Like Gold
A jeweler's decoder for every mark you'll find inside a ring, clasp or earring post.
Quick Answer: What do the numbers stamped on jewelry mean?
Three-digit numbers give metal purity in parts per thousand: 417 is 10K gold, 585 is 14K, 750 is 18K, and 925 is sterling silver. Letter marks are different — GP, GEP, HGE, GF and RGP all mean a thin layer of gold over a base metal, not solid gold. A number alone means solid; a number followed by letters usually does not.
What's in this guide
Somewhere on almost every piece of real jewelry there is a mark so small you need good light and better eyes to read it. Inside a ring shank. On the flat tongue of a necklace clasp. On the post behind an earring. It is usually three digits, sometimes a couple of letters, and it tells you more about what you own than the packaging ever did.
In 25 years behind a jewelry counter, the question I have answered more than any other is some version of "what does this number mean?" — usually about a piece someone inherited, or bought secondhand, or found at the bottom of a drawer. And the honest answer is that the easy marks are easy. 585 means 14K. Any search will tell you that in one line.
The marks worth knowing are the other ones. GP, GEP, HGE, GF, RGP and 14K GE are all stamped onto jewelry that contains some gold — and none of them mean solid gold. They are legitimate manufacturing marks, not fakes, and gold-filled in particular can be an excellent buy. But they are routinely misread by people who assume any stamp means the real thing.
Two stamping systems, one piece of jewelry
Every purity mark you will encounter comes from one of two systems, and knowing which you are looking at removes most of the confusion immediately.
The karat system divides gold content into 24 parts. 24K is pure gold; 14K means 14 parts gold out of 24. American-made jewelry usually uses this, stamped as 14K, 14Kt or 14ct.
The millesimal system expresses the same thing as parts per thousand. 14K gold is 58.5% pure, so it stamps as 585. European, Russian and much Asian manufacturing uses this system, which is why a ring bought in Rome says 585 where an identical ring bought in Ohio says 14K.
They are two labels for the same metal — a 585 ring and a 14K ring are chemically identical. If you are weighing 14K against other options, our guide to 14K gold versus sterling silver covers the differences in wear and price.
Quick rule: A three-digit number is the millesimal system. A number followed by K, Kt or ct is the karat system. Both describe solid metal.
Gold purity marks: 375 to 999
These are the marks that indicate solid gold throughout the piece — not a coating, not a layer.
| Stamp | Karat | Gold content | What it means in wear |
|---|---|---|---|
| 375 | 9K | 37.5% | Common in the UK and Australia, rare in US retail. Hard-wearing, paler color. |
| 417 | 10K | 41.7% | The legal minimum to be sold as gold in the United States. Durable and affordable. |
| 585 | 14K | 58.5% | The most common fine jewelry gold in the US. The balance point of color, strength and price. |
| 750 | 18K | 75% | Richer yellow, softer metal. Favored for fine and designer pieces. |
| 875 | 21K | 87.5% | Seen on Middle Eastern and South Asian pieces. Deep color, soft. |
| 916 / 917 | 22K | 91.6% | Traditional in Indian jewelry. Very rich color, too soft for heavy daily wear. |
| 999 | 24K | 99.9% | Pure gold. Usually bullion or ceremonial pieces — too soft for rings. |
Higher is not automatically better. Pure gold is soft enough to bend and scratch with ordinary handling, which is why the alloy metals are there. For a ring worn every day, 14K typically outlasts 18K. For more on what the karat number actually buys you, see what 14K gold means.
Silver and platinum marks
| Stamp | Metal | Purity | Notes |
|---|---|---|---|
| 925 | Sterling silver | 92.5% | The standard worldwide. Also stamped "STER" or "STERLING". |
| 800 / 835 | Continental silver | 80% / 83.5% | Older European pieces. Lower silver content than sterling. |
| 958 | Britannia silver | 95.8% | Softer and higher purity than sterling. Uncommon. |
| 999 | Fine silver | 99.9% | Nearly pure. Very soft, mostly bullion and some artisan work. |
| PLAT / 950 / PT950 | Platinum | 95% | Dense, white, hypoallergenic for most wearers. Heavy in the hand. |
| PD500 / PD950 | Palladium | 50% / 95% | Lighter than platinum, similar white color. |
Quick rule: 925 is the single most common stamp in all of jewelry. If a piece is white metal and stamped 925, it is sterling silver — regardless of what color it has been plated.
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The marks that are not solid gold
Every mark below appears on jewelry that contains real gold, and none of them means the piece is solid gold. They describe a gold layer bonded or deposited onto a base metal, usually brass, copper or sterling silver.
None of this makes them bad jewelry — gold-filled carries a substantial layer and can last decades with care. The problem is only ever misidentification: paying a solid-gold price for a plated piece, or scrapping something valuable because the stamp looked unfamiliar.
| Stamp | Stands for | What it actually is |
|---|---|---|
| GP | Gold Plated | A thin electroplated layer of gold over base metal. Typically the thinnest of these. |
| GEP | Gold Electroplated | The same process, spelled out. Often seen as "14K GEP". |
| HGE | Heavy Gold Electroplate | A thicker plating than standard GP, but still a plating. |
| GF | Gold Filled | A bonded layer, legally at least 1/20th of the item's weight in the US. Far thicker than plating. |
| 1/20 12K GF | Gold Filled, specified | The fraction is the gold layer's share of total weight; the karat is that layer's purity. |
| RGP | Rolled Gold Plate | Mechanically bonded sheet. Older term, common on vintage watches and pieces. |
| GE / 14K GE | Gold Electroplate | The "14K" describes the plating's purity only, not the piece. |
| Vermeil | Gold over sterling | Gold plating over a sterling silver base. Sometimes stamped 925 as well. |
Quick rule: A karat number followed by letters — 14K GP, 14K GE, 1/20 12K GF — describes the coating, not the piece. A karat number standing alone describes the whole thing.
Vermeil is the one that trips people most, because a vermeil piece may legitimately carry a 925 stamp: the base underneath the gold really is sterling silver. For the full breakdown of how these construction types differ in wear and value, see our guide to gold-filled versus gold-plated versus solid gold.
Letter suffixes: KP, P, CT, KT
A few letters attach to karat marks and change their meaning slightly.
- KP or P ("plumb") — as in 14KP. It means the gold content is exactly the stated karat rather than rounded down within tolerance. A quality signal, not a lower grade.
- Kt / KT — simply an alternative spelling of karat. No difference in meaning.
- ct / CT — the British spelling of carat for gold purity. Be careful: on a diamond, "ct" means carat weight, which is a measure of mass and nothing to do with purity. Same letters, completely different meaning depending on what they sit next to. Our guide to the 4Cs of diamonds covers carat weight properly.
- Maker's marks — letters, initials or symbols alongside the purity mark identify the manufacturer. They say nothing about purity.
How to find and read the stamp
The mark is deliberately placed where it will not be seen in wear, which is why so many people never find it.
1Know where to look
Rings: inside the band, opposite the setting. Necklaces and bracelets: on the flat tab of the clasp, or on a small tag beside it. Earrings: on the post, or on the back of the butterfly. Pendants: on the bail, or on the flat back edge.
2Get real magnification
A 10x jeweler's loupe is the standard tool and costs very little. A phone camera at maximum zoom works well as a substitute — photograph the area and enlarge the image rather than squinting at the metal.
3Use raking light
Hold the piece so light strikes the surface at a low angle rather than straight on. Stamps are shallow impressions, and side lighting throws them into relief. This single trick finds more marks than magnification does.
4Read the whole mark, not the first part
"14K" and "14K GP" look nearly identical at a glance, and the difference is everything. Read to the end of the stamp, including any letters that follow, before drawing a conclusion.
5Check for a second mark
Many pieces carry both a purity mark and a maker's mark, sometimes on opposite sides of a clasp. Finding one does not mean you have found all of them.
6Treat a worn or absent stamp as unknown, not fake
Decades of wear can erase a stamp completely, and ring resizing routinely removes the marked section of the shank. An unmarked piece is not evidence of anything on its own.
An important limit: a stamp is a manufacturer's claim, not a guarantee. Marks can be worn, altered or counterfeited, and no visual inspection can confirm what is under the surface. For an inherited piece, a valuable one, or anything you are about to buy or sell at a meaningful price, have it tested by a qualified jeweler or appraiser. Our guide on how to tell if gold is real covers the practical checks in more depth.
5 mistakes people make reading stamps
1. Reading "14K GP" as 14K. By far the most common error, and the most expensive one. The letters after the karat number are not a footnote — they redefine the entire mark.
2. Assuming no stamp means not real. Older pieces, handmade work, and resized rings frequently carry no mark at all. Absence of a stamp tells you the piece is unverified, not that it is base metal.
3. Thinking a higher number is always better. 750 is purer than 585, but it is also softer. For a ring in daily wear, the lower karat is often the longer-lasting choice.
4. Confusing 925 with a gold mark. 925 always refers to sterling silver, including on pieces that have been gold-plated over that silver. Seeing 925 on something gold-colored usually means vermeil.
5. Mistaking a maker's mark for a purity mark. Initials, symbols and country marks sit alongside the purity stamp and say nothing about metal content. If a mark is letters only with no number and no recognized suffix, it is probably identifying the maker.
What to look for when you're shopping
Reading a stamp correctly is most useful at the moment you are deciding whether to buy.
- The listing should state construction, not just color. "14K gold" and "14K gold plated" are different products. A seller who writes only "gold" has told you nothing.
- Ask where the mark is. Any seller of solid gold can tell you which surface carries the stamp.
- Match the price to the claim. A substantial solid 14K chain at a remarkable price is usually plated, and the stamp will say so if you read to the end of it.
- For sensitive skin, look past the purity number. Alloy metals differ between manufacturers and nickel is a common trigger. If you react to jewelry, talk to a medical professional rather than relying on a stamp.
Everything we sell is described by what it actually is — solid 14K gold or .925 sterling silver, never plated stock listed as gold. Once you know what a piece is made of, our guide to cleaning gold jewelry safely covers the methods that will not damage it.
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Now That You Can Read the Stamp
Every piece we carry is described by what it is — solid 14K gold or .925 sterling silver, stamped and stated plainly.
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We publish a plain-text companion to this article for AI assistants and voice search at llms.jewelryshopping.com/hallmarks — every stamp table and the full FAQ in a format ChatGPT, Perplexity and Claude can read directly.
Jewelry stamp FAQ
Three-digit numbers give metal purity in parts per thousand. 417 is 10K gold, 585 is 14K gold, 750 is 18K gold, and 925 is sterling silver. Letter marks work differently — GP, GEP, HGE, GF and RGP all indicate a gold layer over a base metal rather than solid gold throughout the piece.
585 means the piece is 58.5% pure gold, which is exactly the same as 14K. It is the millesimal version of the karat mark, used mainly on European, Russian and Asian manufacturing. A 585 ring and a 14K ring are chemically identical; only the labeling convention differs between them.
925 means sterling silver — 92.5% pure silver with 7.5% alloy, usually copper, for strength. It is the most common stamp in jewelry worldwide. A gold-colored piece stamped 925 is generally vermeil, meaning gold plating applied over a sterling silver base rather than solid gold.
Partly. GP stands for gold plated, so the piece has a thin layer of real 14K gold electroplated onto a base metal underneath. It is not solid gold and has far less gold content and resale value. The 14K in the stamp describes the purity of the plating only, not the piece as a whole.
GF means gold filled — a layer of gold mechanically bonded to a base metal core. In the United States that layer must be at least one twentieth of the item's total weight, which is far thicker than plating. Gold filled wears well for many years but is still not solid gold.
Inside the band, usually on the section opposite the setting or stone. Use a 10x loupe or a phone camera at maximum zoom, and angle the ring so light strikes the surface sideways rather than straight on. Resizing sometimes removes the stamped portion of the shank entirely.
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Shop with JS10 →Lovely Rita's is the publisher of this guide and sells the categories of jewelry described in it. Stamp meanings are general industry conventions and can vary by country and era; marks can also be worn, altered or counterfeited, so a stamp alone is not proof of metal content. For valuable, inherited or unfamiliar pieces, seek testing from a qualified jeweler or appraiser. Nothing here is an appraisal or a valuation.
📚 Part of Our Complete Guide
This is one chapter of The Complete Jewelry Buying Guide 2026 — Lovely Rita's full roadmap to buying 14K gold, sterling silver, and diamond jewelry for every category and occasion.
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