A Gemological Institute of America (GIA) spokesperson confirmed to Jeweller that the organisation had developed a fully automated sorting device for round, D to Z melee-sized diamonds – those weighing between approximately 0.005 carats and 0.2 carats.
In addition to sorting samples by size and colour, the system will be able to separate natural diamonds from potentially treated and synthetic stones.
While the GIA has been screening larger diamonds for treatments and undisclosed synthetic origins for decades, the GIA spokesperson said it was “impossible” to do the same for melee-sized stones until now due to their small size and high quantities.
“The rapid development of synthetic diamond growth technology – especially in melee sizes – and the lack of efficient, affordable means to detect them have resulted in industry concern that synthetics and treated diamonds could be mixed in parcels with natural stones,” the spokesperson explained.
“This new GIA service will give the industry – as well as the consumer – confidence in knowing what they are getting for the most prevalent stones in the market.”
It was said the device could process about 1,800 stones per hour and, once fully operational, would be capable of running 24 hours, seven days a week.
The GIA will pilot test the device during the first half of this year, with the new melee screening service to launch in the second half.
As previously reported by Jeweller, several other melee screening systems have recently been developed. The WTOCD (the Antwerp Scientific Research Centre for Diamonds) announced the launch of the M-Screen device in collaboration with international grading laboratory HRD Antwerp last year, while Surat-based business Dharmanandan Research Centre (DRC Techno) also launched a diamond detection system called D-Secure around the same time.
HPHT technology advancements
News of the GIA melee screening service follows reports from the organisation’s researchers on the rapid advancement of HPHT (high pressure, high temperature) synthetic diamond technology and the impact this will have on the jewellery industry.
In March, GIA researchers released analysis of a 5.03-carat emerald cut HPHT blue diamond. The stone was supplied by Russian manufacturer New Diamond Technology and was believed to be the largest of its kind studied by the GIA.
Later that month, the organisation examined another 50 stones developed using the same technology. The HPHT diamonds, manufactured by Chinese company Jinan Zhongwu New Materials, ranged in size from about 0.5 carats to 1.2 carats.
Jinan Zhongwu New Materials indicated it was producing large quantities of gemstone-quality, colourless and blue diamonds up to 3.5 carats in size, which the researchers noted was “undoubtedly significant”, even though the manufacturer’s exact production volume remained unclear.
“This strongly suggests that even more large HPHT synthetic diamonds will be introduced into the jewellery industry,” the report concluded.
GIA researchers are still conducting detailed gemmological and spectroscopic analyses on the Jinan Zhongwu New Materials stones, with their findings to be reported at a later time.
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