The Gem Lab that refuses to grade synthetics


The LFG in Paris has taken a stand against man-made diamonds. Its director, Aurélien Delaunay, explains why.

The French Gemmological Laboratory (LFG) is the oldest of its kind in the world. Founded in 1929, it came into being after the arrival of cultured pearls on the market prompted more than 300 pearl dealers from Paris’s 9th arrondissement to call for a way to differentiate them from natural pearls. The French government managed the lab from 1936 until 2010, when it was sold to the French Union of Jewellery (UFBJOP), today its majority shareholder. Aurélien Delaunay has been its director since July 2018.

What is your lab’s specialty? 

The LFG’s strength is that it is multidisciplinary. Our specialty is our privileged link with the University of Nantes, known worldwide for its research wing in gemology and mineralogy. Prof. Emmanuel Fritsch is also our external scientific adviser, with whom we set up research projects, particularly on diamonds.

We are also the only laboratory that refuses to grade synthetic diamonds. We offer our services to an extremely varied clientele, ranging from the key houses of the Place Vendôme to auction houses and museums. We are particularly proud to have been able to warn about the discovery and presence of synthetic chemical vapor deposition (CVD) brown diamonds. We have also published many articles with Emmanuel Fritsch on chameleon diamonds. Our latest discovery was a natural type IIa/IaB zoned diamond. We collaborate with [Gemological Institute of America (GIA) journal] Gems & Gemology, [The Gemmological Association of Britain’s] Journal of Gemmology and the French Journal of Gemmology.

Why did your lab decide not to grade synthetic diamonds?

It is a joint decision of the profession and the UFBJOP not to grade synthetic diamonds, unlike other international laboratories. These stones do not have to be evaluated on the same scale as natural ones, because they are an imitation of the diamond and must remain so.

This decision is unanimous in the profession except for those who want to promote this [lab-grown] material. But it must be remembered that the increase of synthetic diamonds on the market will bring down their price. Also, natural diamonds will always be desired for what they are, a rare and precious natural resource. The question of the grading of synthetics matches a logical view of things: If they are graded, this must also be done for other synthetic stones. Also, not grading these stones helps to differentiate and isolate them.

How are you dealing with the increase of undisclosed lab-grown diamonds on the market? 

We regularly analyze synthetic diamonds, but we cannot say that their proportion has increased in our volume of analyses. We saw a lot between 2012 and 2013, but with the awareness of the diamond industry and the development of analytical tools, things have stabilized. The improved sourcing of our customers has clearly contributed to this decrease. Also, we might have 0% synthetic stones in a batch, or up to 20% when [the batch] is not correctly sourced. But our annual average is less than 1% synthetic in melee batches. It can nevertheless be said that problems still come from India, where the presence of synthetic diamonds in lots is widely known.

In which areas do you think the industry needs more training?

The presence of synthetic diamonds on the market is a major issue. But there is much work to do on the terminology of [describing] gems, as well as on the disclosure of the different treatments. In France, we are fortunate to have a law, Decree No. 2002-65, which clarifies things. But this is not the case everywhere.

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Author Marie Chabrol

Source Rapaport