Most modern jewelry has one, if not more markings stamped somewhere on the piece.
Stamps are used to identify the piece’s metal content, carat weights, manufacturer, designer, jewelry, and legal trademark. These markings tell the buyer what the piece is made of, what it’s worth, and can be used to track and recover stolen jewelry.
Usually, you’ll find these stamps near the clasp of necklaces and bracelets, on the inside of rings, and on the back of earrings and pins.
However, these stamps aren’t always easy to understand. Luckily, they’re much easier to explain.
What Does 9k, 10k, and 12k Mean?
The k behind these numbers stands for karat.
One karat represents 1/24th of the piece of jewelry’s entire gold content.
24k gold is 100% pure gold.
9k gold is 37.5% pure gold, the rest being a mix of alloy metals.
10k gold is the lowest solid gold alloy used for jewelry. It’s 41.7% gold, and 58.3% alloy, and is used for its durability.
Because it’s more alloy than gold, it can handle a fair amount of wear and tear. It’s also the least expensive option for gold alloys.
10k gold can be used to make any kind of affordable jewelry, but it’s most commonly used in earrings.
It’s pale yellow, and the least yellow of all the karats because it has the least amount of gold.
Some people might be allergic to the alloy used, and the color isn’t as attractive as other karats.
12k means the piece is made of an even 50% gold and 50% alloy.
12k gold is more valuable than 9k or 10k, and has a brighter yellow hue; although it’s nowhere near as vibrant as pure 24k gold.
14k gold is the most common karat for jewelry. It’s 58.3% gold and 41.7% alloy.
Most jewelers and buyers prefer 14k gold because it is the perfect balance of durability, affordability, and appearance.
It looks close enough to pure gold, but it can handle everyday wear– because of this, it’s the most common type of gold used for engagement and wedding rings.
However, there is still the potential for allergic reactions due to the level of alloy metals.
To prevent allergic reactions, it’s possible to buy jewelry that is gold plated, or gold-filled– this keeps the skin from touching the alloy metals and circumvents the allergic reaction altogether.
Fortunately, if the wearer is allergic to gold, there are plenty of other options available.
Also called hallmarks, purity, or quality marks, these stamps are the most common markings, and the most important stamps on any piece of jewelry.
They show the karat weight of the metal, shown as 10k, 14k, or 18k.
The k stands for karat, and the number is the percentage of that metal found in the jewelry.
For example, 14k gold means there is 58.5% gold, and the rest is a mix of different alloys.
Here’s a table to show the most common metal stamps, and their meanings.
|9K||9 karat gold, usually sold in the UK (not the USA)|
|10k||10 karat gold (can be white or yellow gold)|
|12k||12 karat gold (usually found outside of the US)|
|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 pure 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 stamped karat weight or higher)|
|PLAT or PT||Platinum|
|900 or 950||Platinum|
|S.S or St. Steel||Stainless Steel|
|Silver or S. Silver||Sterling Silver|
|925 or .950||Sterling Silver|
|KP||Karat Plumb- this means the metal is verified to be at least the stamped karat weight, if not more.|
|G.F or G.P||Gold Filled or Gold Plated|
|SOL||Solitaire Diamond (usually followed by a carat weight)|
|Any Number||In some cases, a jeweler will put the ring size in the shank|
|CW||CW means the carat weight of the gems in the ring|
|WGD||Weight gold, as in 14k or 10k weight|
The next most common stamp is the carat weight. This is for the gem in the ring, and it’s pretty easy to read.
If you see a stamp-like .50CW, it means the gem is half a carat. In rings with several gems, you might see two-carat stamps.
Usually, the first number stands for the center jewel, and the second number stands for the total weight of the other stones.
These weights are usually stamped as simple numbers, but you might also see ct, CW, or carat after it; you’ll rarely see the stamp “tdw”, which means total diamond weight.
In the United States, jewelry manufacturers are required by law to inform their buyers about the precious metal content in their jewelry, but it doesn’t have to be stamped on the jewelry itself.
It can be given verbally when appraising the item, on the price tag or packaging, or even on the invoice or receipt for the purchase.
If you can’t find the metal stamp on your piece of jewelry, be sure to check these places.
If the manufacturer does stamp the jewelry itself, they are legally required to stamp their trademark beside the metal stamp.
This is meant to assure the buyer that the company making and/or selling the jewelry guarantees and/or vouches for the accuracy of the metal content.
Unfortunately, there is no legal requirement for stamping non-precious metals, like tungsten, stainless steel, and titanium, although many manufacturers will stamp this anyway.
Also known as maker’s marks, a jeweler’s stamp shows where the ring was purchased from.
Sometimes jewelers will abbreviate the store’s name, or use a logo. Every jewelry store is different and uses different markings.
Examples are the mark JBR, which is the stamp for J. B. Robinson Jeweler’s; or the mark Pgda, which is the stamp for Piercing Pagada.
Jeweler’s marks are registered and can be widely recognized and easily tracked. Often, a jeweler’s stamp might change over time.
By knowing or recording which mark was used at what time a historian or appraiser can easily date an item.
In addition, these “maker’s marks” verify the authenticity of the item, ensuring that the quality is maintained and the piece cannot be legally replicated.
The jeweler’s mark becomes a part of their trademark, creating their brand’s reputation and proof of their craftsmanship.
The manufacturer’s stamp shows who made the ring. For example, the Tiffany jewelry company marks their products with T & Co.
These stamps brand the object as theirs and helps to keep their company image.
This is useful to know if you need to contact the manufacturer for questions, concerns, or ordering more jewelry.
In some countries, manufacturer’s marks are assigned and kept on a register and are often overseen by some form of state or federal government.
A lot of jewelry designers put their name on their designs– the same way an artist signs their masterpiece.
Often, the stamped name of a designer can make the piece of jewelry much more valuable.
For example, Tiffany & Co has a number of Paloma Picasso designs, and these pieces will be engraved with that name.
For most well-known brands, any engraved name is most likely to be the designer.
However, this is not always the case, and won’t always be a correct assumption. Always check the designer registry and databases, to be sure.
If you find a name and/or date that you can’t identify as a jeweler, manufacturer, or designer, it might be an engraving.
These are usually only found on antique or vintage pieces, as the original buyer must request that the piece be engraved.
Engravings can be messages, names, dates, or initials, and can offer clues about the piece’s past owners.
If your jewelry has been engraved, you have the option of taking it to a jewelry historian, who can investigate where it was first manufactured, who designed it, who sold it, and who originally owned the piece.
It can be a fun and educational insight into the life of your jewelry.
These are the most common stamps. Also known as makers marks, these protect the names, logos, or initials of jewelry manufacturers, importers, wholesalers, or retailers.
These marks are registered with the country’s Patent Office and can be tracked if necessary, which is especially helpful in recovering stolen or altered jewelry.
Mistakes and Alterations
Unfortunately, it’s pretty easy to mess up a stamp.
Sometimes the stamps imprint at the wrong angle or are marred, making the markings uneven, blurry, or hard to read.
Jewelers could have easily used the wrong stamp by accident.
Jewelry can be modified: gems can be swapped out and mountings can be redone.
In these cases, jewelers might forget to restamp jewelry with the correct information.
If there is no stamp, it’s most likely that your piece is costume jewelry: not worthless, but nowhere near as valuable as stamped jewelry.
However, this may not always be the case. Most older pieces of jewelry will be missing markings, as well.
It may be because manufacturers were not required to stamp their products.
For antique pieces, such as those found in archeological finds or those that were worn on a daily basis, the markings may have worn away over time, by skin oils or less-than-ideal conditions.
If the jewelry has been significantly altered, it can change the piece from what it was originally stamped as.
More basic repairs, such as resizing, doesn’t usually change the item too dramatically. But when resizing an item, a ring, for example, may remove important marks.
This would make it difficult to identify the manufacturer, jeweler, and designer of the piece, but the metal make up is still the same.
However, if the piece is made into something else completely, every stamp would need to be changed.
Even replacing a gem would change the carat weight stamp.
Sometimes, these mistakes aren’t so innocent or accidental.
To make jewelry seem more expensive, forgers can polish off markings and illegally replace them, and then sell the pieces for a higher profit.
Some jewelry thieves do the same, polishing away any traceable stamp– like the designer’s, manufacturer’s, jeweler’s, or trademarks, making it harder for them to be found and arrested.
International scamming has become more and more common, with imported jewelry being incorrectly stamped in order to pass as more expensive.
There is a common example of a 14k gold plated ring, the mark written as 14kg; the g was polished off, so the ring could be sold as solid gold.
However, a clever buyer would know that 14kg, is not a stamp at all, and be able to spot the fake.
Because of this, you should always be aware of who you’re buying from, and make sure they and their company is trustworthy.
When buying jewelry, always get it appraised– this will ensure the stamps are accurate, and that you’re paying the correct amount for what you’re getting.
If you’re still unsure of the metal or gold content of your jewelry, take it to your local jeweler and ask them to do an acid test.
There are a few tests you can do at your home, but there is no way of knowing for sure without a real test performed by an experienced technician.
A certified appraiser will be able to determine the value of the piece, as well.
Markings are useful and necessary for modern jewelry.
They help us identify and track products, help people with metal allergies to avoid their allergens, and help to spread a designer, jeweler, or manufacturer’s specific brand.
Always be sure to do your own research, and to get your items appraised, to prevent yourself from being overcharged or buying a fake or altered piece of jewelry.