The marks stamped inside jewelry indicate not just the source or manufacturer of the jewelry, but also the weight in carat of the precious metal, the jeweler involved (or the designer) and any pertinent trademarks that must be made identifiable in the jewelry. Today, we will focus on jewelry stamp meanings, so you become more knowledgeable about how rings and jewelry are categorized and identified. Knowing what the stamps mean will guide you when purchasing different kinds of jewelry, from bracelets to rings to earrings.

What is the Use of Marks?

The number of stamps or marks used for jewelry is huge, so it’s impossible to list them down. You will need an entire website dedicated to jewelry marks or stamps to get a good idea of the breadth of how many they are. There are also unidentified marks that seem to have special meanings, but they were never truly shared by the designer or manufacturer to people in the first place. Some examples of unidentified or unknown jewelry marks are 4862, JC, heart with an arrow mark, .3 al, KG, and more. The list of unknown marks go on and on, and since there are also thousands of small scale and large scale jewelry manufacturers globally, things can get a little iffy when you want to know the meaning of each recorded jewelry mark.

Marks for Identifying Metals

Like a precious metal’s weight in carat, it’s also important to know what kind of metal was used to produce the jewelry. There are several international signs used to indicate the metal type in jewelry. PLAT, PT, 950, and 900 are used for platinum jewelry. S.S., Steel, and St. Steel are marked for stainless steel jewelry. Silver, S. Silver, and Sterling Silver may be stamped on sterling silver products. Sterling silver is strengthened or alloyed silver, while fine silver is 99.9% silver, which is softer and more prone to dents and damage when handled or used regularly. 925 and .950 are also marks for sterling silver. The difference in the percentage of silver is due to regional or geographic differences in standards. For example, in France, the quantity of silver required before a piece of jewelry can be stamped sterling silver is higher than 92.5%.

What about gold jewelry?

Gold jewelry can be marked with a variety of figures related to their carat weight. Gold jewelry can also be either gold-plated (GP) or gold-filled (GF). If more advanced electroplating was used, the manufacturer might opt to stamp GE instead of GP on a ring or jewelry piece. WGD, on the other hand, means “karat weight gold.” KP refers to karat plumb, which means there is a minimum amount of precious metal in the jewelry. Still, there can be more depending as there are often minuscule discrepancies in the production of jewelry.

What are other marks used for other metals other than silver, platinum, and gold?

Some jewelry contains special metals that give them special characteristics, like additional durability. Titanium jewelry should have “Titanium” or similar marks, while “Tungsten” is used for tungsten-containing jewelry. And finally, there is Pd, which indicates the presence of palladium in the given alloy.

Marks for Identifying Carat Weight

Carat weight is determined by the quantity of the precious metal versus the metals used for alloying. There are several types of marks used to denote the carat weight of a piece of jewelry. 9k refers to nine-karat gold, which is more common in the United Kingdom but not in the US. Other marks denoting the carat weight of gold are 10k, 12k, 14k, 18k, 20k, 22k, and 24k. Many of these carat weight values apply to rose gold, yellow gold, and white gold, except 24k, which can only be yellow gold because of its high purity.
Additional marks indicating the purity of the precious metal are also used to indicate quantity for metals like platinum. For instance, 900 Platinum indicates that the piece of jewelry has 90% platinum purity. This cart weight system applies to various metals in the platinum group, including palladium and rhodium.
Take note that karat is different from carat. Carat is the measurement for the purity of gemstones, not precious metals. While some careless jewelers make the mistake of using these weighing systems interchangeably, they are not. It would be best if you asked about the purity of the precious metal and the precious stone separately.

Marks by the Jeweler

Jeweler marks indicate stamps or marks from the store or company that is selling the jewelry to you. In the United Kingdom, the assay company or testing company has a different mark from the brand or “sponsor” of the jewelry. The system began in the 1300s. The marking for purity was a step in the right direction to prevent manufacturers from cheating the market by reducing the number of precious metals in different items, not just jewelry. Some examples of jeweler marks are MGD (Mary Grace Design) and SAI (for Sai Krishna) based in India.

Trademark identification is easy in this respect because you will only have to look at unusual letter or numerical combinations that do not correspond to the karat weight of the gold or precious metal. Unseal combinations are often the registered trademarks of the jeweler or manufacturer. In the case of some jewelry, they may also indicate the source of the precious metal, like NV, which stands for the Nevada Silver Mine.

Take note that metal marks or jewelry stamps can also be wrong. Unscrupulous individuals or entities can put the wrong type of purity stamp on jewelry. There are also instances when a piece of jewelry is remounted (like a ring), and the change in the purity of either the gemstone or the remounted metal is not declared. The best thing you can do is to buy only from reputable sources of jewelry and scrutinize all of the documentation offered to you at the time of purchase. This applies most, especially when you visit department stores or jewelry stores physically.