ASDI stands for Automated Spectral Diamond Inspection. It is a device which can analyse and authenticate very large quantities of colourless melee diamonds at a low cost. It was developed by SSEF with collaborating partners and is currently marketed by SATT Gems SA. ASDI can:

– Colourless round melee diamond authentication

– Separating diamond imitations

– Separating HPHT treated diamonds

– Separating synthetics (CVD & HPHT)

– Customizable size-sorting (optional)


The machine uncovers colourless synthetic diamonds, both HPHT and CVD grown, as well as colourless HPHT-treated diamonds.

In 2007, the Swiss Gemmological Institute SSEF and the electronic laboratory of the University of Basel joined their expertise and launched the ASDI project. After five years of research & development, OPTEC Industries brought their know-how in automation and size-sorting.

Finally in 2013, the first ASDI machine was operational at the Swiss Gemmological Institute SSEF and since then, has screened more than a million of colourless melees hereby protecting the Swiss watch and jewellery industry. As a result, four ASDI units are now operating at two major Swiss diamantaires and two major Swiss watch and jewellery groups.


Diamond Positioning

An operator pours a large batch – several thousand – of colourless melees into a vibrating bowl that delivers each single stone onto a rotating glass plate. A series of specially designed arms positions each stone table down and separates them. A digital camera pre-checks each stone for their size, position and clearance before analytical inspection begins.

Diamond Inspection

A Raman probe identifies all possible diamond imitations that are automatically ‘rejected’. Then, a highly sensitive spectrometer checks the short wave ultraviolet (SWUV) transparency of each diamond. If its transparency is significantly high, the stone would be automatically rejected as a potential HPHT treated diamond or a potential synthetic diamond (HPHT or CVD grown).

Diamond Size Sorting (Optional)

A series of digital cameras record up to fifteen different measurements for each single authenticated diamond (precision for diameter measurements: ± 0,005mm). An automatic sorting system distributes the diamonds into a maximum of four different bins according to their size. This function is conveniently customizable and has no impact on the ASDI sorting speed.

For more information on ASDI, pricing and contact details please visit SATT Gems SA.