National Jeweler Network

Grading

De Beers’ melee screener to go in Antwerp lab

By Michelle Graff

January 29, 2014


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.

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.

Following testing, the diamonds are automatically dispensed into one of five bins:
-- Pass: The stone is not a synthetic or a simulant. Trials have indicated pass rates of 95 to 99 percent for natural melee;
-- Refer: A rare result, this indicates that more testing is needed;
-- Refer Type II: The stone has a low concentration of nitrogen and further testing is required, as it may be synthetic;
-- Non-diamond: The stone is a simulant or synthetic; and
-- Purge: This bin is for when the user needs to empty out the machine because, for example, they placed the wrong packet of diamonds into the device.

Because the machine feeds and sorts stones automatically it can be left unattended, and one person can operate multiple machines at a time.

However, unlike the GIA, De Beers won’t be leasing its device at no cost in exchange for data, or selling it to the general trade, at least not right now.

De Beers said it will offer three-year leases on the device, which was developed by De Beers Technologies UK, to sightholders through the International Institute of Diamond Grading & Research (IIDGR) in Antwerp for $25,000 a year. De Beers declined to say which sightholders would be leasing the machines.

Founded in 2008, the IIDGR is part of the De Beers Group of Companies and is a grading and research center that offers a range of diamond grading services and specializes in developing verification instruments.

In addition to leasing the machines to sightholders, De Beers will install multiple melee screening devices at the IIDGR later this year. The cost of the screening service is yet to be determined and while the details are still being worked out, it will be available to the general trade, De Beers said.

When asked if De Beers plans to sell the device to the trade, a spokeswoman for the diamond miner and marketer said the “initial plan” is to lease the device to sightholders, which are the “current priority at the moment.”

De Beers tested the device last year in a pilot program at the IIDGR. A number of the devices also were deployed to diamond centers worldwide, to measure the impact of different environmental conditions on the machine’s performance, De Beers said.

After receiving what it describes as “strong expressions of interest from many sightholders,” De Beers opted to begin manufacturing the melee screener.

De Beers’ release of information about its automated melee screener comes on the heels of the GIA’s official announcement on Monday that it had developed the DiamondCheck, a screening device for the detection of lab-grown as well as HPHT-treated diamonds as small as one point in size.

The GIA is leasing the machines to diamond bourses around the world at no cost in exchange for data about the stones that get screened. Through GIA Instruments, it is also selling the DiamondCheck to the wider trade for $23,900.

The bourses currently slated to receive a DiamondCheck are in New York, Mumbai, Dubai, South Africa, Hong Kong, Tokyo, Shanghai and Tel Aviv.

Absent from this initial list is the bourse in Antwerp, one of the world’s main trading hubs, though the GIA said Antwerp, along with other diamond centers, likely will receive a DiamondCheck later in the first quarter.