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.
Hello, I recently found a piece of jewelry and on the back it has S 55, I’ve put a magnet to it and it does not stick, which means it is not metal and it is some type of element, how do I tell which one? It’s an oval piece, the front top is a bow and connected to the bow on the right is the 1st diamond and continues with diamonds in the Oval pattern until it reaches the other side of the diamond and there are a total of 15. The back is gold with S 55 .
Hi Sara,
It’s hard to tell from your description what the metal is. Is the whole item gold, or just the back? S 55 does not correspond to any known metal stamp.
I have an earring with 750 on it which I believe means 18k then signature with numbers 377633. What do those numbers mean? I’m sending my email this time.
Hi Ana,
750 is indeed the stamp for 18k gold. The 377633 doesn’t indicate anything about the metal; my guess is that it’s the manufacturer or designer’s stamp.
Hello! My husband’s class ring is stamped MJ 10K on the inside. He can’t remember who made it and he needs to get it resized. It is a gold colored high school ring from 1983. I’m sure the 10K refers to the gold content. He thought perhaps the MJ referred to Jostens, but I called them and they said it wasn’t them. Can you help identify the company that made the ring?
Hi Lindy,
Not sure about MJ…it doesn’t seem to correspond with any of the big class ring manufacturers. But if he needs it sized, you can actually send it on over to us! We can size 10k gold. Just check out our ring resizing services here.
I have a pair of clip on earrings that look like feathers or leafs it is stamped L18k what does the L STAND FOR
Hi Jeremy,
Since the 18k indicates the metal content (75% gold), it’s safe to assume that the L is probably the manufacturer or designer’s stamp.
Hi! I have a bracelet that have a mark CT and below 18750. It have a few marks so I don’t know if it’s gold plated. Thanks 🙂
Hi there,
Several pieces of jewelry on vintage jewelry sites and Ebay are also marked CT 18750, and they all seem to be gold-plated. Your bracelet probably comes from the same manufacturer.
Hi there! I have a diamond necklace and am wondering the quality of it. On the necklace itself by the clasp it says ITALY and the diamond pendant on the inside says 10k SUN. Is there anything you can tell me about this piece?? Thank you
Hi Brenda,
Sounds like you have a piece of Italian jewelry that was created for export. Within Italy they prefer to sell 18k gold and higher; your item is only 10k gold which is 41.6% gold content.
I have a 14k gold diamond ring set they ring says 14k on it but it also has a small S stamp in it to and the other ring also has 14k stamp into it but also has JST what do those two mean?
Hi Amber,
The stamps are manufacturer’s stamps. There’s a jeweler who uses the JST stamp in California; they’re probably made your ring set.
Hello! I recently purchased a ring ant it is stamped with an upside down “U” (at least that’s what it looks like), 14k I know that’s the carat weight and a three point crown. I have scoured the internet and cannot find anything remotely close. I’m starting to think I was duped. Have you seen or heard of any hallmarks like this?
Hi Kila,
Unfortunately no, we haven’t. The 14k stamp indicates the gold content, which is 58.3% gold.
Hi, I purchased what I assume is a vintage necklace. Like another poster, the clasp (it’s a bayonet) says “Germany.” There is a tumbled amethyst pendant that hangs off a rope chain (very white in hue…so maybe silver…no markings, though) and the pendant mount is shaped in petals.
Any idea about the age? I was assuming 70s, because it looks very similar in style to my mother’s from the 70s.
Thanks!
Hi Julie,
Hard to tell; the GERMANY stamp has been seen on pieces from around the 1950s. If the style is similar to your mother’s from the 70s that could be a safe bet in regards to its manufacturing age.
Hello,
I have a large gold eagle pendant that (stamped on the back) has a letter C inside of a circle, followed by the stamp “harlequin” “1975” followed by 14 KT EP 0001. I can’t find any information on this piece anywhere-would you be able to tell me any information about these stamps?
Thanks so much!
The circled c is a stamp indicating copyright, which means that your item was definitely made after 1955 when the US passed copyright laws for jewelry designs, supported by the 1975 stamp. 14kt EP means your item is gold-plated, and my guess is that the 0001 may be 0.001 of a millimeter, which is exactly 1 micron of gold plating. Harlequin is most likely the manufacturer/designer’s stamp.
I have a tested 14k gold pendant of a horse inside a heart. It has a copyright symbol (C inside a circle) and 14KGD. I am thinking the GD is the maker’s mark, since we tested it to be 14k gold. Some research has provided me with the name George Day in London? Do you know this maker? Any other info you can provide? THANKS!
Hi Sharon,
The 14KGD stamp is commonly used by a variety of manufacturers. Some pieces are in fact solid gold, while others are gold-plated. Based on the description alone, it seems odd that there’s a copyright symbol on this piece if it’s genuine high-quality jewelry, as the copyright symbol is generally used for branded costume jewelry.
Hi there-I love this site, Thanks so much for all the great info. I was wondering if you knew anything about a diamond lozenge shape stamp/mark with either MtZ or MZ with a cross in between the M & Z inside the lozenge shape. It’s on a set of plain white metal bangles and there are no other markings. The metal is non magnetic & doesn’t react to platinum test acid so it may be plat or stainless steel. Any help with the makers mark would be very much appreciated. One last thing the lozenge shape is on its side (Eg the width is more than the height)
Hi Kaleigh,
That certainly sounds interesting; unfortunately we’ve never seen this M+Z mark so I’m afraid we can’t date this piece or identify the manufacturer.
Hello,
I have a silver-colored ring with a small green center stone and tiny “diamond” side stones. Inside is engraved SIL. Is this costume jewelry?
Hi Fran,
The SIL mark is a silver mark associated with jewelry from the UK, New Zealand, and Australia. Based on this information your item is probably costume jewelry.
Hi have a bracelet on one side it has 925(A but its too hard to make out if its an A) and on the other side it says 10
Hi Devin,
925 is the mark for sterling silver (92.5% silver content) and the other stamps are probably designer/manufacturer stamps.
I have been left a ring it has 18ct Plat on it but also 59,57 do you know what that might mean
Hi Carly,
It’s probably the manufacturer/designer mark if it doesn’t indicate anything about the metal.
I have an old ring pre 1970 with a 10k stamped on it and another number that is so worn down only the number 3 is visible at the end and the ring is some kind of precious metal any information about what it could be or where i could find out would be great. It also has a large blue stone that reflects light in a star pattern across the stone and i cant figure out what kind of gemstone it is.
Hi Austin,
Sounds like you found yourself a star sapphire ring! If it’s vintage and 10k gold (41.6% gold), chances are it’s probably a Lindy/Linde star sapphire. The gem is synthetic (manmade), but Lindy pieces can fetch a nice price ($100+) online.
Hi
I have a few pieces of jewelry that have 925 with an R next to it sometimes the R is flipped upside down and sometimes it has a curvy look. Do you know what it represents?
Hi Stephanie,
The R is most likely the manufacturer/designer’s stamp. The 925 indicates that your item is sterling silver, or 92.5% silver.
Hi,
I have a ring with a 18CT mark inside, thats the only mark I can find.
What does this mean?
Hi Jamie, this means that your item is 18k gold, or 75% gold.
I have an old piece of jewelry marked Amerik FBM.
What that means?
Hi Luca,
The item was manufactured by Friedrich Binder Moehnsheim.
Hi, i have a gold pendant with an amethyst (i think) in it, it says 375 on it which is circled then under that it says GM16
Does that tell you anything about the ring?
If not and it is a manufacturer/maker mark, do you have any idea who it could be?
Hi Keren,
375 is 9 karat gold, or 37.5% gold, which means that your item is probably of British origin since the minimum gold content requirement for manufacturing in the U.S. is 10k.
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