Purity marks on gold jewelry will consist of a two-digit number followed by the letter “k,” or a three-digit number. The letter “k” refers to karats, where pure gold is composed of 24 karats (24k). A piece of jewelry with an etching that reads “18k” or “750” indicates that it is made up of 75 percent gold, while a “14k” or “585” mark indicates the metal is constructed with 58.5 percent gold.
Jewelry engraved with HGE (Heavy Gold Electroplate), GE (Gold Electroplate), or GF (Gold Filled) may appear to be made of gold, but it is actually fashioned from other materials such as copper and contains only a very small amount of gold.
Silver purity marks also specify metal content (for reference, sterling silver is 92.5 percent pure silver). Therefore, for sterling silver, look for marks that include “925,” “STERLING,” “STG,” or “STER.” Keep an eye out for metals that are etched with “German Silver” or “Nickel Silver.” These pieces are not made up of any silver at all, but are actually composed of copper, nickel, and zinc. If jewelry is marked with “Vermeil,” it is a piece of sterling silver topped off with gold plating.
When considering platinum jewelry, the purity mark “950” denotes a composition of 95 percent platinum with a mix of other metal alloys, while “900” is made up of 90 percent platinum, and “850” has 85 percent platinum.
Maker’s marks may include logos, trademarks, company names, and designer signatures to specify who made the jewelry. Iconic jewelry maker Tiffany & Co., for example, has featured several maker’s marks throughout their 179-year history, including “Tiffany & Co.” and “T & Co.” Special edition Tiffany & Co. jewelry collections created by designers Frank Gehry, Paloma Picasso, Jean Schlumberger, and Elsa Peretti also bear their respective designers’ signatures.
With antique and vintage pieces, French jeweler and watchmaker Cartier adhered to several guidelines set forth by the French government. Modern Cartier jewelry is always engraved with the Cartier logo, along with a serial number unique to each individual piece.
Van Cleef & Arpels jewelry will also include a serial number accompanying the brand trademark. Depending on the era of the piece, the maker’s mark either reads “Van Cleef & Arpels” or the letters “VCA.”
Jewelry from the United Kingdom contains a series of compulsory and optional jewelry marks set out by the countries’ assay offices. One of the compulsory marks is the Assay Office Mark, a symbol which indicates the regional office that hallmarked the item. Assay Office Mark symbols include an anchor that signifies Birmingham, a castle for Edinburgh, a leopard’s head for London, and a rose for Sheffield.
“International, particularly European, jewelry typically has hallmarks, while American jewelry is usually stamped 14k or 18k,” says Virginia Salem, head of the jewelry and watches department at Freeman’s. “Hallmarks tell the story of the piece, and usually what country the item came from, as well as the artist and date made.”
Starting in 1838, an eagle’s head stamped on a piece of gold jewelry indicated that the jewelry was from France and that it had a minimum of 18k gold. Additionally, a boar’s head was the mark of the Paris assay office, while offices outside the capital city used a crab emblem.
Since gold, silver, and branded jewelry are highly sought-after, encountering fake jewelry is always a risk that collectors need to keep in mind. If you’re purchasing jewelry online, always ask for clear pictures of the jewelry marks from the seller to ensure the authenticity of a piece.
Auction houses and jewelry dealers in particular are important resources for learning more about jewelry maker’s marks. Prior to bidding online or in-person, you can request additional information from jewelry specialists should you have any questions or concerns. When bidding at auction on Invaluable, for example, an easy way to connect to specialists is to use the “Request more information” button located on the product page. The same option exists if you’re considering a purchase from an Invaluable dealer or gallery.
The best way to safeguard against buying imitation jewelry is to familiarize yourself with the most important jewelry marks and signature hallmarks of specific brands. While there are countless jewelry marks to know, additional resources for collectors include the Birmingham Assay Office. Salem adds that Lang Jewelry University, which is well documented and covers a wide range of estate jewelry, is also an excellent reference guide for further detail about specific markings.