De Beers’ melee screener to go in Antwerp lab

Michelle Graff

London – De Beers is now in the manufacturing stage with its melee screener and will lease it to interested sightholders in the second quarter before placing the device in a grading and research facility it operates in Antwerp, making it open to the trade more generally.

The machine, officially dubbed the Automated Melee Screening Device, or AMS, screens near-colorless or colorless diamonds as small as one point and up to 0.20 carats to determine if they are natural, De Beers said.

Unlike the screening device for synthetic and high-pressure, high-temperature- (HPHT) treated diamonds introduced this week by the Gemological Institute of America that tests one stone at a time, De Beers’ device can take up to 500 carats of melee at once and automatically feeds the stones, table-down, into a measurement station.


De Beers’ Automated Melee Screening Device scans stones between one point and 0.20 carats in size and automatically sorts them into one of five bins: pass, refer, refer Type II, non-diamond and purge.

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Source National Jeweler