I must get at least one email a day that asks me about the stamp marks (also called hallmarks) inside their ring.
Everyone wants to know what they mean?
Hopefully this post will answer that question.
The most common marks or trademark stamps are used to identify things like:
Metals, carat weights, manufacturer, tradeMarks, jeweler, or designer.
The mark that is the most important is the metal stamp, or karat weight of the metal.
P.S. I also have an ENORMOUS list of unidentified stamps as well: unidentified stamps inside rings (If you know any, help me out and drop me a line)
If you look inside the shank of your ring (the band on the bottom or side), you’ll usually see the karat stamp. More than likely it will be shown as 10k, 14k, 18k or Plat. These are the most common metals and most common markings. But you’ll also run across titanium, stainless steel, tungsten, sterling silver and even palladium (plus some other obscure metals, like those used in class rings – lustrium, lLazon, celestrium?).
Karat weight can be written a number of different ways. Each manufacturer is different and can use different terminology. Take a look at the chart below and then we’ll talk about them.
Common metal marks stamped inside rings
|9k||9 Karat Gold usually sold in the UK (Not in the USA)|
|10k||10 Karat Gold (Can be White or Yellow Gold)|
|12k||12 Karat Gold (Found more out of the states)|
|14k||14 Karat Gold (Can be White or Yellow Gold)|
|18k||18 Karat Gold (Can be White or Yellow Gold)|
|20k||20 Karat Gold (Can be White or Yellow Gold)|
|22k||22 Karat Gold (Can be White or Yellow Gold)|
|24k||24 Karat Pure Gold (Yellow Gold)|
|.417||10 Karat Gold (Can be White or Yellow Gold)|
|.585||14 Karat Gold (Can be White or Yellow Gold)|
|.750||18 Karat Gold (Can be White or Yellow Gold)|
|.833||20 Karat Gold (Can be White or Yellow Gold)|
|.999||24 Karat Pure Gold (Yellow Gold)|
|P||Plumb Gold (must be the karat weight stamped or higher)|
|900 or 950||Platinum|
|St. Steel||Stainless Steel|
|S. Silver||Sterling Silver|
|Sterling Silver||Sterling Silver|
|.950||Another Silver Mark unlike 950 for Platinum|
|CZ||There is a Cubic Zirconia stone in the ring (and not a diamond)|
|G.F. or G.P.||Gold Filled or Gold Plated|
|SOL||Solitaire Diamond (usually followed by some carat weight)|
|6,7,8,9,10||(A number) Some jewelers put the ring size in the shank|
|cw||CW means the Carat Weight of the diamonds or gems in the ring|
|WGD||Weight Gold, as in 14 Karat Weight Gold, or 10 Karat Weight Gold|
Hallmark Stamp Books
There are some Books on the Market that may help as well:
A Closer Look…
To explain the numbers above a little bit better, they are actually percentages of that particular metal that are mixed with other alloys. For example, 14k gold is 58.5% Gold and the rest are alloys mixed in with it (like silver and copper to make it more durable).
So .585 means 58.5% or 14k gold.
10k is also written as .417 (41.7% gold).
18k is .750 (75% gold).
When you see KP stamped inside your ring, which is a “P” at the end of the stamp, like: 14kp, that means that the gold is “Plumb” which means it’s verified to be at least that karat weight marked or more. So if it’s 14kp, it’s at least 14kt gold or higher!
Platinum can be written as platinum, plat, 900 or 950. The 900 means that it is 90% pure platinum and 10% alloy. 950 means it is 95% pure platinum and only 5% alloys mixed in (which gives you a higher platinum content).
Carat weights are the next most common stamp inside a ring. Carat weights are pretty self explanatory. If you see a number like 1.01, that would mean that the diamond set in the ring is 1.01 carats (One carat and one point).
.50 would mean that a half carat (50 points) is set in the mounting.
Sometimes you will see two carat stamps inside the shank which would mean one stands for the big diamond (usually center solitaire), and the other stamp stands for the total weight of the side stones.
Carat weights are usually just stamped like “.75“, but sometimes you’ll also see ct or carat after it, like .75ct. You may even run across one that looks like this: .75tdw, which means total diamond weight, or the entire diamond weight of all the diamonds in the ring.
Many times the number will also be followed with cw, meaning it’s the carat weight of the gems or diamonds in the ring.
A common stamp that you’ll see inside rings are jeweler’s stamps so you can tell where you bought the ring from. Like “JBR” inside the shank would stand for J.B. Robinson Jewelers, “Pgda” stands for the Piercing Pagoda, Helzberg Diamonds will stamp “Helzberg Diamonds” right inside their rings.
Sometimes these jewelers will abbreviate their store’s names or even use a logo. Every jeweler is different and uses different markings.
Just like the jewelers, often you’ll see the manufacturer stamped inside the band of the ring. For example ArtCarved will stamp their rings “ArtCarved” so they know it’s their ring and it also helps brand their company, product and image. Take Tiffany for example, they stamp their rings “T & CO“.
Manufacturer stamps can be very useful if you need to find out who made a ring so you could contact them for questions, concerns or even ordering!
There are a lot of great jewelry designer’s out there that put their name right inside their rings. A great designer’s name can carry a lot of weight. A huge designer that most people know would be David Yurman which is stamped © D.Y.
If you buy a trademarked piece of jewelry, I’m certain it will contain a trademark inside the ring. Trademarks are like the LEO diamond or the Hearts Of Fire diamond (HOF).
If you buy a special cut of diamond, or a trademarked name, look for the stamp, it’ll be there.
One thing you have to keep in mind, is sometimes the stamp is uneven, blurry, or hard to read. This happens when the stamp is hit at a wrong angle, skids when it’s hit, or doesn’t make full contact when it’s imprinted. Often 14 will look like a P, H, or something else. You could also be reading it upside down.
To find out for sure what the letters and numbers are, you should pick yourself up a 10x jeweler’s loupe for perfect identification, even better, a microscope for your iPhone that will take close up pictures at 60-100x optical (very cool device that is pretty inexpensive, but fun to use).
Take a look at some examples of marks and different stamps inside of rings…
Marks Stamped Inside Rings
Let’s take a quick look at the images marked 1-7 above…
1) PLAT .46 – This is an interesting ring because you can clearly see that the ring is yellow and not white like platinum. This is a pretty rare instance, but the PLAT stands for the platinum (not plated) head. The diamond (46 points – just shy of a 1/2 carat) is set in a platinum head. The rest of the ring is 14k yellow gold. If I had shown the other side of the ring, you would have seen another stamp that said 14k.
2) R.M.I. 14k – R.M.I. is the manufacturer’s mark and 14k is the 14k yellow gold content.
3) FA PT 900 © – The FA stands for the manufacturer or designer’s initials. The PT means platinum (as well as the 900) and that the ring is also copyright ©
4) 10k – Easy as pie, 10k white gold.
5) 14k NIIi – 14k white gold made by a designer or company with the initials of NIIi.
6) 585 – 585 stands for 14kt gold, white gold in this instance!
7) 18k 750 – Often you will find both karat stamps and their percentage stamps inside of rings. 750 is the same thing as 18k gold (white gold).
Marks can also be wrong!
Keep in mind, things can happen. Stamps or marks can be wrong. The diamonds could have been swapped out, or the mountings reused. The jeweler could have forgot to restamp the correct information on the ring. You never know. They could have also grabbed the wrong stamp (literally a metal stamp, called a karat punch steel stamp, like this one HERE and a forged steel chasing hammer) and struck the wrong info. Plus, some rings don’t even have any stamps. You should know though, that rings sold in the USA should. If it’s not stamped, it could be anything.
A jeweler also wrote in telling me they’ve run across customers who polish out marks inside rings. For example, a ring had the engraving “14KGP“, which stands for 14k gold plated, and they buffed out the P, so it looked like 14KG (not knowing that 14 karat gold is written as 14K, and not 14KG). You just don’t know what you’ll run across.
Any stamp could be wrong or altered!
To be sure of the gold or metal content of any ring you can take it into a local jeweler and have them do an acid test on the metal.
I have seen some silver plated jewelry stamped as sterling silver… NOT GOOD! Plated jewelry should always have GP, GF or PLATED inside the ring. And as always, you should get an appraisal with any jewelry you purchase. Just to be sure.
Markings help us in a lot of ways. They help identify a ring. They help jewelers identify their product. They brand companies and designers. Plus, it also helps people identify possible problems with allergies to gold and nickel.
And if you really must know…
Jewelry Hallmark Stamp Books
So there you go…
What does your ring say?
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Author Richard Scott. Certified Diamontologist\Gemologist. 30 years of experience.
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