【Paris, Franc】Jewelry: Behind the Scenes at the French Gemmology Laboratory that Certifies Precious Stones

Editor’s Note

This article highlights the French Gemmology Laboratory (LFG), the world’s oldest gemmology lab. Founded in 1929, it remains the only certified laboratory in France, providing scientifically based analysis reports for gems, diamonds, and pearls to both professionals and individuals.

“The LFG is open to all, but our primary clients are jewelers, especially those on Place Vendôme, luxury houses belonging to major groups (Richemont, LVMH…), houses like Cartier, Van Cleef & Arpels, Boucheron, Chaumet, Chanel, Hermès, Christian Dior, Louis Vuitton… and jewelers from Paris and the provinces, as well as all those orbiting around them, such as traders, suppliers, workshops, and diamond dealers. People working with auctions, i.e., auctioneers, experts, and antique dealers, also call upon us. A very small portion of our clientele consists of individuals (5 to 10%).”

“An individual comes to find out what they own: for example, in the case of an inherited piece of jewelry as part of an estate, they may not always have the exact traceability of the stone. Another case: an individual who has purchased a stone and wants to verify what they bought may need a document to justify the value of their item to insurers. Finally, when commissioning a jeweler to create a piece, they may need a stone identified before setting it.”

“The professional or individual deposits their stone(s) in a secure booth: this is when the administrative staff registers the request. The file is then assigned a number; everything is anonymized to ensure impartiality. For each file, several mandatory tests are conducted: weighing the exact mass of the stone or jewelry (which influences its final value), measuring its dimensions, taking photos of the stones and their inclusions. There is also 3D scanning (for diamonds to assign a cut grade, type 1 or 2), Raman and infrared spectrometry (for colored stones), micro-radiography and tomography (to observe the internal structure of pearls).”

“All these tools allow for an initial measurement to determine the exact nature of the stone. We fill out a work sheet, validated by the team, as it represents the opinion of the entire laboratory, avoiding any issues of impartiality or analysis error. This preliminary examination includes identifying the material, any treatments, and in some cases, the origin: the analysis report contains all the properties and characteristics of the stones. Of course, color, purity, and cut assign a certain value to the stone, but we do not provide financial estimates; that is not the role of the laboratory, which has a scientific role for completely independent analysis. We produce 5,000 reports per year and see 1.5 million stones.”

“We have always seen them, and the laboratory was created for this purpose in 1929—to distinguish natural stones from synthetic ones, cultured pearls from natural pearls. Today, we indeed see more large synthetic diamonds. In mixed lots of diamonds (melee diamonds, small diamonds), we saw many in the years 2012-2013 because, at that time, the industry had not taken the necessary measures to control the lots at several sourcing stages. Now, we see far fewer. The trade is committed to being transparent about its sourcing and the quality of the lots it supplies to jewelers. If we still see synthetic moissanites (note: a synthetic stone that is a good imitation of diamond), it is not, however, in very significant volume.”

“The challenges are numerous. Our clients have a need for control, to know what they are buying; it’s a current demand.”

Full article: View original |
⏰ Published on: December 10, 2021