Clean, simple elegance - those words have defined the timeless style of Georg Jensen jewelry, flatware and holloware throughout the history of the company. Jensen developed and finely honed his skills and style during his apprenticeship for a goldsmith beginning in 1880. He then opened his first silver shop in Copenhagen in 1904, where his focus was on creating "democratic design" - items of functional beauty that were available to everyone. These designs enhanced and breathed a new energy into the then-contemporary Art Nouveau styles and lines of the times. Fast-forward over a hundred years to today, and those century-old designs continue to be coveted. Although new Georg Jensen wares reflect current styles, they remain true to their maker's original concepts, incorporating them into the distinctive Jensen style.
Jensen pieces of all types and ages are sought after, collectible and retain high values - sometimes commanding prices even higher than similar Tiffany items. Because other Danish pieces can closely resemble Jensen with their clean, simple lines, some sellers attribute them to Jensen and ask high prices; some of these sellers are making innocent mistakes in identification, while others deliberately deceive buyers. Either way, you need to know what to look for to identify true Georg Jensen pieces.
Virtually all pieces made by Jensen have a maker's mark; in fact, some collectors say that if there's no Jensen mark, it's not an authentic Georg Jensen piece. Like many other manufacturers, the mark changed throughout the years. There is no gap in Jensen marks between 1904 and the present day, but there are some overlaps, when two or more mark styles were used in the same years. Marks range from a stylized "GJ" to "Georg Jensen Copenhagen" to marks with a crown logo or dotted circle. Check reputable reference sources to make sure any mark you see is authentic.
Jensen set the tone and high quality standards for his works but allowed his carefully chosen designers the freedom to express their own design ideas. On some pieces, you'll find the artist's mark alongside the Jensen mark, including those of Johan Rhode, Just Andersen, Gundolph Albertus, Harald Nielsen and Henning Koppel, among others. Other marks indicate date, model number, manufactory and silver content along with guardian, duty or import stamps, which have also been used on some pieces. The types of marks used sometimes depended on the space constraints of the piece.
It's easy to question whether a piece of Danish jewelry without any maker's mark is actually Georg Jensen, but can every piece with an authentic Jensen mark be trusted unquestioningly? The answer is, unfortunately, no. There are amalgamations and altered Jensen pieces that the discriminating buyer needs to watch out for. Sometimes modifications only lower the value of a piece slightly, but other times they can strip its value completely. A slight modification would be replacing a broken stone or adding a stone to a piece that never had one - as long as the addition enhances the piece and doesn't destroy the integrity of its original style or purpose, the piece will still retain value. However, when a portion of a Jensen piece is merged with a non-Jensen piece so that the original Jensen mark remains, that piece is no longer considered to be Jensen, and no value is retained.
Another problem that arises when a signed portion of a Jensen piece is fused with a non-Jensen item is that the newly created piece may fool buyers (and sometimes sellers) into thinking they've found a previously unknown and undocumented piece. Unscrupulous sellers intent on deception may label such pieces as one-of-a-kind experimentals or as a unique piece made for a personal customer request. Some jewelry amalgamations don't even reflect the intended purpose of the original Jensen portion - one example of this would be if a signed portion of a Jensen earring has been fused with non-Jensen pieces to create a pendant. These pieces were clearly made to deceive and are not considered Jensen. Therefore, it's important to check high-priced Jensen pieces against either old Jensen catalogs or current reputable reference sources; you can also have the piece authenticated by a knowledgeable collector or expert.
Many times, non-Jensen jewelry pieces with Danish lines contain elements favored by Jensen, like bunches of grapes, flowers, leaves, or other things from the natural world, making them easy to misidentify. There have also been copies made of Jensen pieces or new pieces marketed as being in the style of Jensen, Jensen inspired, in the Jensen tradition, or "Jensenesque" - none of these are true Georg Jensen.
A lot of confusion also came about from pieces marked Georg Jensen USA - these pieces were made in New York around the time of World War II, and buyers assumed the Danish Georg Jensen firm had opened a factory there. However, these were not the same maker, even though their style resembled that of the original Danish company; many of these pieces are still in circulation today and are collectible in their own right. On the other hand, Jensen pieces from jewelry to table wares are being copied and produced in Mexico, especially the blossom-type patterns; a reclining cat pin made in Mexico has also been identified. Coro, the well-known jewelry company especially popular for their midcentury designs, also copied Jensen pieces with amazing likenesses.

Photos via Google Images (labeled for reuse).

At A Glance
Signs of a non-Jensen piece:
1. Pieces with a USA mark
2. Pieces made in Mexico
3. Amalgamations

Reference books, websites and collecting groups are the best ways to keep from being fooled by fakes. Here are a few: The Georg Jensen Society (http://www.gjsilver.org/front.htm); “Georg Jensen: Holloware” by David Taylor and Jason Laskey; “Georg Jensen: 20th Century Designs” by Janet and William Drucker; “Jensen Silver: The American Designs” by Nancy Schiffer and Janet Drucker.