There’s an old saw that most of us only know when we’ve seen a good opera because someone told us so. The same is true with jewelry. Beautiful costume jewelry can often sell for peanuts compared to clunky fine jewelry that features a brand name. Likewise, gold-filled jewelry sells for a fraction of solid gold equivalents, yet it’s sometimes nearly impossible to tell the difference. In fact, those tiny letters and numbers stamped into the metal deliver a lot of the information you should know. Those are hallmarks.
In the US, two 20th century laws proscribe specific types of hallmarks for American-made jewelry. The first, dating to 1906, requires an indication of metal purity and the second, dating to 1961, identifies the maker. Hallmarks required on continental jewelry go back much farther, to the 14th century in England and the 13th century in France. Of particular note is legislation enacted in France in 1797 that requires all maker’s marks be framed by a shield or diamond-type border.
Gold and silver hallmarks are somewhat more universal. Gold purity is measured in karats with 24 karats representing the highest value. Gold jewelry marked “750” or “18k” indicate a blended metal consisting of 75% gold and 25% other elements. Likewise, a “585” or “14k” imprint indicates a gold content equal to 58.5% of the whole. Marks of HGE, GE, and GF indicate Heavy Gold Electroplate, Gold Electroplate, and Gold Filled, respectively; all indicative of a lesser intrinsic value.
Silver is hallmarked similarly. Sterling silver is in most countries standardized at 92.5% pure silver. Marks such as “Sterling” or “.925” or “STG” are indicative of this content. Here again, SP (Silver Plate), EPNS (Electro-Plated Nickel Silver) and German Silver include little or no actual silver and are characteristic of costume rather than fine jewelry.
If your taste runs to platinum, the number “900” indicates a 90% platinum content and 10& other metals. Marks such as “850” or “800” indicate similar proportions of platinum to other alloys.
Things start to get complicated when we come to maker’s marks. Such premier jewelry makers as Tiffany have used several different identifiers in their long history, including “Tiffany & Co.” and “T and Co.” Sometimes prominent Tiffany designers such as Paloma Picasso will warrant their own separate hallmarks. Cartier hallmarks have also varied over the years according to legal requirements but more modern pieces will always carry the full Cartier name along with an individual serial number. Any contemporary piece without those two indicators should be viewed with suspicion.
With continental jewelry, assay marks often take over from there. While American makers generally stick to the required “14k” or .925″, hallmarks found on European jewelry are often rooted in assay office or guild requirements from years past. Some relate to purity, others to particular makers, and still others to locale or era. English jewelry with a lion imprint indicates sterling while a “Britannia” marking identifies an even higher silver content. Gold jewelry has an even more bewildering array, often according to region of origin. There are entire books on the subject of hallmarks and serious buyers need to make a study of them.
Of course, if you’re buying jewelry to just wear and enjoy, forget the hallmarks and buy what you like. You can never lose that way.