Jewelry Hallmark Guide

If you own a piece of precious metal jewelry, you have likely noticed a small stamp on a hidden part of the ring, necklace, bracelet or earring. These stamps are known as a jewelry hallmark, and appear on almost all precious metal jewelry. Jewelry hallmarking can give you clues as to the jewelry’s country of origin, metal content, purity, and the name – or initials – of the maker.

European Hallmarks
Hallmarking has a long and illustrious history that began in Europe during the 14th century. English and French jewelers in particular hallmarked their jewelry with elaborate designs and animal symbols to denote the origin of the jewelry, the metal, the purity, and the maker. Though intricate and lovely, the European hallmarks can be tough to decipher and are easily misinterpreted by a novice. Luckily for Americans, the U.S. jewelry hallmarking system is much easier to read.

American Hallmarks
Though many countries require jewelers to hallmark their precious metal jewelry, the United States interestingly does not. Yet despite the absence of a law mandating hallmarking, most U.S. fine jewelry does indeed come stamped to assure the purchaser of the quality of the metal. Since the purity of the metal is a major indicator of the jewelry’s value, many jewelry buyers feel more comfortable purchasing a piece that is hallmarked. However, it is important to note that a hallmark can also give a buyer a false sense of security since it is not tightly regulated in the U.S. Unscrupulous jewelers or street vendors can create their own hallmark to pass off poor quality jewelry as quality pieces. The most important factor is always to buy from a reputable jeweler.
Here is a quick rundown of the most common jewelry hallmarks that indicate the metal and purity:

U.S. Platinum Jewelry Hallmarks
Plat - A platinum ring marked with Plat or 950 Plat is considered nearly pure platinum (95% platinum) and is therefore quite expensive. 950 is the highest grade of platinum available for jewelry.
IridPlat - Platinum rings with this hallmark are 90% pure platinum with 10% other metals mixed in. These rings, also often marked with .90 Plat, cost less than their purer platinum counterpart above.

U.S. Gold Jewelry Hallmarks
10k - 10 karat gold is the lowest karat gold, and is composed of 10 parts gold to 14 parts other metals. 10 karat gold costs much less than higher gold purities.

14k - 14 karat gold is one of the most popular gold purities for gold jewelry. 14 karat gold is composed of 14 parts gold and 10 parts other metals.

18k - 18 karat gold is very high quality gold, and is composed of 18 parts gold and 6 parts other metals.

24k - 24 karat gold is pure gold, and is the most expensive and most malleable gold composition. The addition of other metals to gold makes it stronger and more durable, since 24 karat gold is quite soft and is easily dented, dinged and bent.

U.S. Silver Jewelry Hallmarks

 900 - The 900 stamp on silver denotes that the metal is 9 parts pure silver and one part alloy metal. This stamp was used mainly on silver coins and is not commonly used on jewelry in modern times.

925 - 925 is the hallmark stamp for sterling silver. This is the most common hallmark seen on silver jewelry, and means that the jewelry is composed of 92.5% pure silver and 7.5% other metals. Sterling silver is the highest quality silver used in jewelry, since pure silver is much too malleable to be worn on a daily basis.