SSEF Launches Service for Melee Diamonds

Basel: The Swiss Gemmological Institute SSEF has announced the successful conclusion of validation testing of the ASDI-500, the newest version of the Automated Diamond Spectral Inspection device, developed with Swiss robotics company UNIMEC SA. The system is able to screen very large quantities of round colourless polished melee, detecting and extracting synthetics and simulants from among the natural diamonds.

More information on the service is available at:

The positive results provide a green light for the inauguration this June of a testing service for round colourless diamond melee down to 0.5 millimetres in size, for both the Swiss and international diamond and jewellery trade.

The validation programme began after SSEF and UNIMEC SA first introduced the ASDI-500 at the GemGenève Show in November 2022. The programme involved the screening of more than 500,000 round diamonds with diameters ranging from 0.50 millimetres up to 3.80 millimetres, using a strict double-checked internal procedure.

The testing batches were doped with both synthetic diamonds and diamond simulants, all of which were detected and sorted out by the ASDI-500 device.

The ASDI-500 device uses a built-in high-precision robot entirely manufactured by UNIMEC SA. It picks up the diamonds individually, latching onto them while they are in the pavilion-up position. A special nozzle was designed so that the diamonds’ culets are never in direct contact with the robot’s pick-and-place mechanism. This protects the tip of diamond, or culet, from any damage during the testing procedure.

“Ten years after launching the Automated Spectral Diamond Inspection device, the first-ever device developed to authenticate large batches of small diamonds, SSEF and UNIMEC are proud to offer the diamond industry the ASDI-500. This is a next generation instrument that allows automated diamond authentication, especially in the size segment between 1.00 millimetres and 0.50 millimetres, for which no automated solution existed thus far. We are pleased make available this new authentication service to our customers,” said Jean-Pierre Chalain, Project Manager and Director of the Diamond Department at SSEF.

 “To sustain consumer confidence, it is necessary to develop high-quality and reliable screening solutions that have been adapted to watchmaking needs,” said Dominique Dubugnon, Head of the Gemmological Commission at the Federation of the Swiss Watch Industry FH. “It’s essential to maintain the high level of quality for which the Swiss industry is known.”