Many of us have seen the small numbers or letters engraved inside a ring band or near the clasp of a piece of jewelry that we own. But how many of us understand what information those stamps are actually giving us?
In this post, we’ll walk through the different stamps, what they mean, and what you need to know about stamping laws to ensure you’re getting the most accurate information about your jewelry. Let’s start with the basics:
- 10K, 14K, 18K, 24K, etc – if this is the ONLY stamp on the piece, it is telling you first and foremost that the piece is solid gold and secondly, the karat fineness of the gold. For example, let’s look at 14K. 14 out of 24 particles in the metal are pure gold. The others can be a mix of elements including palladium, copper, etc. These additional elements are what determine the specific color of the gold (we’ll talk about this in an upcoming post).
750 stamp on jewelry means 18k Gold - 417, 585, or 750 – this is just another way of telling us the gold content. However, instead of referring to how many parts out of 24 are pure gold, this number is now out of 1,000. So for 10K gold jewelry, 417 out of 1,000 parts are pure gold. For 14K gold jewelry, 585 parts out of 1,000 are pure gold. So when you see 750 that means 18K gold jewelry because the metal is made of 750 parts per 1,000 of pure gold.
- 900, 900PT, PT900, 950, 950PT, PT950 – all of these stamps designate that the piece is made of one of the two most common platinum alloys. 900, 900PT, or PT 900 all signify that the metal used is 900 parts per 1,000 pure platinum, while 950, 950PT, and PT950 denote 950 parts per 1,000 are pure platinum.
- 925 – a piece with this stamp is made of sterling silver. Legally, to be considered sterling silver a piece has to consist of 92.5% pure silver, with only 7.5% other elements mixed in.
- GP – pieces with this stamp have been plated with gold, but have another metal underneath. It almost always has the karat fineness of the plating listed, i.e. 18K GP.
- HGE – this is the abbreviation for high grade electroplate, which is another way of denoting that the jewelry you are looking at is not solid gold. These pieces also generally display the karat fineness of the gold.
- GF – this stands for gold-filled, which is a term that means a thin layer of gold was bonded to a base metal to make this piece.
So now that we have the basic stamp meanings down, let’s go through some of the most frequently asked questions that we hear from customers:
There’s another symbol next to the metal content stamp that isn’t on your list. What does that mean?
Most likely, the stamp you are seeing here is the manufacturer’s trademark or the trademark of the retailer selling the piece. This is legally required if the item is stamped and serves as a guarantee of sorts that the manufacturer/retailer vouches for the accuracy of the stamp on the metal.
My jewelry piece isn’t stamped at all. Does this mean it’s not made of precious metal?
Not necessarily. The legal guidelines on stamping don’t require all pieces made of precious metal to be stamped. However, they do require the manufacturer or retailer to disclose any precious metal content. This could be via discussion in the store upon purchase, on a tag attached to the piece, or on the receipt for the product itself.
The clasp/closure/earring backs on my piece are stamped, but the rest of the item is not. Does that mean the whole thing is made of precious metal?
Again, not necessarily. Sometimes the clasp of a piece is made of a different metal than the chain, so definitely confirm with the store clerk or jeweler that the entire item is made of the metal from the stamping. Likewise, earring backs may have been accidentally swapped and may not be made of the same metal as the rest of the earrings, especially the posts, so double checking is always best.
My piece has a name/date engraved on it. Is this the designer or year that the piece was made?
For well-known brands and designers, this can be the case, but it isn’t necessarily a correct assumption. For example, Tiffany & Co. has several Paloma Picasso designs that would be engraved as such and may include the date. However, it could also be that the piece is vintage or estate and was engraved with the previous owner’s name, anniversary, etc.
What other questions do you have about jewelry stamp meanings?
Community Discussion
Questions, experiences, and expert answers from the QJR community.
Help idk what the meaning of these stamps are nor can i completely read one set of the numbers / Nd or letters partly at fault being stamped right directly on top of the 14 kt stamp and on top is what appears to be a very small and delicate possibly even hand drawn heart that is so very tiny and thin may even say Mary but then engraved as one piece it says 27 the numbers and on the other side of the band is some type of a very badly worn symbol may be a circle but i believe it’s a unrecognizable worn heart and there in the middle is a tiny little dot of red paint and no I assure u it didn’t accidentally get on there and hasn’t worn off yet it’s not coming off,lol help me plz ro identify its origin
Hi Tara,
I’m afraid it’s rather difficult to determine the meaning of the stamps on your ring without a picture. Keep in mind that jewelry is often passed down from person to person, so it wouldn’t surprise me if your item was modified by previous owners, especially since you mention hand-drawn symbols and names. It’s common to find engravings on older pieces of jewelry, and it’s near-impossible to find out any information about who engraved it or why because there won’t be any historical records to reference.
The ND on top of the 14kt stamp may be a manufacturer’s stamp, however.
Hi. My diamond band is stamped SDL 14k on the inside. I understand the 14k is the metal content but I’m not sure if the SDL is a manufacturer stamp? Do you know what this means?
Hi Erin,
SDL is a manufacturer’s stamp for SDL Jewelry; they specialize in sterling silver and 14k gold, and they’ve been in operation since the early 1910s.
Hi Erin,
SDL is a manufacturer’s stamp for SDL Jewelry; they specialize in sterling silver and 14k gold, and they’ve been in operation since the early 1900s.
Hey what does c830 means on the inside of the ring.
Hi Mary,
830 has been used to indicate either 20k gold or silver (of either Norwegian or Scandinavian origin).
I have a 10k ring with a C13 or C15 stamped in the inside?
Hi Kevin,
It’s probably the designer/manufacturer’s stamp, since you already know that the ring is 10k gold.
Have a ring looks like small diamonds in it. It is stamped
14K-18K C
Can you tell me what that means thanks tamra
Hi Tamra,
That’s highly unusual to have a range for gold; the 14K and 18K mean 58.3% and 75% gold. My guess is that the ring either contains two types of gold in different locations (especially if it’s two-tone colored) or it may not be legitimate jewelry.
I have a ring that says QTR10K. What does this mean?
Hi Michelle,
10K indicates 41.6% gold content, and the QTR is probably the manufacturer’s stamp.
Thank you!
I have a cross with 1-20D-10K. What is the 1-20D?
Possibly the manufacturer’s mark, since the 10K indicates the gold content. If it had said “1/20” I might’ve guessed your item was gold-filled instead of solid gold (so 1/20 gold content), but the D changes the mark completely.
What does 12.5 mean on gold.
Hi Kelvin,
It doesn’t seem like it indicates gold content; otherwise it would’ve said 12k instead of 12.5. Probably a manufacturer’s stamp.
Hi Annabelle:
I have a bracelet with yellow metal looking like gold with a mark 713S and the marquis stones looking like diamonds. It is very well-made. Hope it is real but not sure? Curious in finding out what the mark “713S” or “735” (cannot make out – hard to read) means? Thank you for helping shed a light into this piece.
Hi there,
Neither of those marks seem to correspond to any known metal stamps, so they’re probably manufacturer’s stamps. You can try getting the bracelet metal tested to see if it’s a legitimate piece of fine jewelry; we also offer appraisal services for the gemstones.
I picked up a bangle and on the inside it has three different marks – the first is PB the second is 22A and the third is RT.
What would each marking stand for? Thanks for your assistance to understand jeweler’s marks
Hi Mel,
You definitely have a strange piece there; none of those marks are metal stamps, and all of them correspond to different manufacturer’s marks. For instances, PB has been used by designers such as Paul Brackna, and RT is a common trademark of several manufacturers as well. I think you’ll need to look at the metal type and the style of the bangle to narrow down your options.
I just purchased a pair of hoop earrings. They were labeled online as “Solid 14k Rose Gold”. The stamp says “14K S”. What does the “S” stand for?
Hi Jessica,
Probably the designer or manufacturer’s trademark, since the 14k is the metal stamp.
I have a ruby ring the only marking in the band is RBP it is either silver or white gold. Can you help me?
Hi Amanda,
RBP seems to be the mark for Raymond Platero, who primarily works with silver.
I purchased a vintage aquamarine ring with the marking “ PLAT APPL’D”. Any idea on what this means? There were other markings, but too faded to make out. Thank you for any insite you may be able to provide.
Hi Natasha,
Are you sure there’s an L in there? PAT APPL’D is a more common stamp that indicates a patent was applied for the company/item. I’ve seen this stamp on items dating from 1850 and up.
Thank you Annabelle, upon a second examination, you are correct it’s PAT APPL’D and I noticed an additional mark of what I believe is UR. Would the UR indicate the maker’s mark? I looked up old jewelry patents and I could not find the one for my ring. It’s been fun researching and thank you for pointing me in the right direction.
Hi Natasha,
Yes, the UR is most likely the manufacturer or designer’s mark. It may be difficult to find the patent since you’re combing through records from 1850 to approximately 1940s-1950s! That’s quite a span.
The style of the ring might be able to help you narrow down the time period, however. There were several distinct art styles that were dominant during those years: Victorian, Edwardian, Art Nouveau, Art Deco, and Retro. Each of them had their own style of settings, preferred stones (and stone cuts) and metals. I’d suggest looking at sample pieces to match your ring to a particular period.
Please what does small heart shape stamp means on a herringbone flat necklace. Thank you
Hi Fatima,
Sounds like it could be Oroamerica’s mark, they were a manufacturer that later merged with another company called Aurafin.
Hi anabelle..
I have a silver bangle which says a small circled c then num 24 inside a diamond then a capital L..
The bangle has no scratches and is encrusted with tiny stones..
Would they be diamonds?
Regards Gina
Hi Gina,
The circled c is a stamp indicating copyright, which means that your item was definitely made some time after 1955 when the US passed copyright laws for jewelry designs (so it’s not going to be an antique piece!) Unfortunately many designers have used the diamond shape/jewel shape for their trademarks, so I’m not able to determine which one manufactured your item.
It seems likely that your piece is costume jewelry given this information, so the tiny stones are probably faux gems.
I have a ring given to me by my grandmother and on the inside is stamped 10k that has a c with a diamond symbol beside the c… any ideas?
Hi Carie,
10K indicates 41.6% gold content, while the c and the diamond symbol are probably manufacturer/designer marks.
Hello, I have a brooch in shape of grapes with little stamp on it’s back in the shape of dolphin. I bought it in Israel in 1991 – 1995, don’t remember exactly what year. Do you know what company made jewelry with this stamp?
Thank you.
Hi Anna,
The only designer I know of that has a similar mark is Hans Jensen, but that’s Denmark-based. If your item is artisan jewelry, there may be no official records as to who the stamp belongs to; many artisans merely stamp to mark the item as their creation but do not register for an actual trademark.
Hi!
I got a ring at an antique shop with markings on the inside of the band that say “4K10.” I’ve searched the internet, and I’m having trouble getting clarity on what this could be. The sales associate at the shop wasn’t sure what the markings could mean.
Do you have any suggestions on what metal it may be?
Thanks in advance!
Hi Carolyn,
4K10 doesn’t correspond to any known metal stamp, so it’s probably the manufacturer’s trademark. As for the metal, I’d need to either see or get more information in order to give you a definite answer. We do offer metal testing services if you’re interested.
What does 14k NIRU mean?
Hi Gin,
Your item is 14k gold, or 58.3% gold. NIRU is the trademark of a jewelry manufacturer that specializes in diamonds.
Please I have a gold jewelry that’s marked CR, what does this mean? Is it real gold?
Hi Ruth,
CR does not indicate anything about gold content- this is probably the manufacturer/designer’s trademark. Many manufacturers have used CR as a stamp, so unfortunately I cannot tell you if your item is fine or costume jewelry. Look for any stamps on your item that have a number and K next to it, like 10k, 12k, 14k, or 18k – those are standard gold stamps. If it does not have such a stamp on it, it is unlikely that your item is real gold.
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