The high-tech net tightens

New manufacturing techniques are making synthetic diamonds harder and harder to distinguish from natural gemstones. For jewellers, therefore, access to the latest screening technology is becoming crucial — it protects the diamond supply chain from contamination and safeguards consumer confidence. Solitaire Gemmological Laboratories holds the key: its superior new V6 screening machine helps keep the synthetics menace at bay.

Rise of CVDs and HPHTs
Synthetics, or lab-grown diamonds, are beginning to cast a long and growing shadow over the worldwide gems and jewellery industry. Manufacturing technology is improving to the extent that synthetics are now hard even for experts to distinguish from natural gems. At the same time, synthetics are being manufactured in ever-greater volumes.

Current peak installed capacity of synthetic diamond manufacturers worldwide is estimated to be 2.3–4.2 million carats, or 2–3 per cent of the total natural diamond supply. This estimate is from a comprehensive study on synthetic diamonds commissioned by the Gem & Jewellery Export Promotion Council (GJEPC), and published in 2017. The study was undertaken by Bonas & Co for the GJEPC’s Natural Diamond Monitoring Committee (NDMC).

According to industry analysts the larger-sized CVD, a type of synthetic diamond (CVD stands for “chemical vapour deposition”, the specific manufacturing technique used), is not the real threat. Current screening technology can identify CVDs.

The real challenge, experts say, is posed by smaller-size CVDs and HPHTs (“high-pressure, high-temperature”). Unofficial estimates have as many as 2.1 million units, in the form of star and melee diamonds, escaping certification surveillance. These CVDs are simply not traceable.
Jewellery manufacturers sometimes purchase loose diamonds from the open market. This practice makes their supply chain vulnerable to CVD infiltration.

V6 does it best
Solitaire Gemmological Laboratories (SGL), based in the United Kingdom, has developed a proprietary V6 screening machine that offers currently the most dependable solution to this problem. Jewellery manufacturers and retailers are using it to keep the CVD threat at bay.

Specialised versions of the SGL machine detect CVDs and HPHTs with precision. The machines can even analyse diamonds that are mounted in jewellery — no need to remove each stone from the piece.

The small, box-like and portable screening machines can scan nine rings and two or three pendants at one time. The process is just 25 seconds long, and the results display instantly on the screen of an ordinary laptop connected to the machine.

How it works
SGL is a pioneer in synthetic diamond screening services. Its machines are state-of-the-art and use techniques such as FTIR (infrared spectroscopy) and XRF (X-ray fluorescence). A full list would include fluorescence, phosphorescence, photoluminescence and spectrum analysis, besides other optical technologies — all of which are designed to identify the exact chemical composition of the material under analysis.

“CVD and HPHT have different atomic structures,” says Chirag Soni, director, SGL. “Using those fundaments [listed above], we have developed technology that has proven successful in detecting such stones in jewellery.”

“We at SGL are at the forefront of understanding the [potential of] new technologies in [identifying] CVDs and HPHTs,” says Shirin Bandukwalla, director, SGL. “We go to the trouble of acquiring rare samples of various lab-grown diamonds to analyse them and come up with the most effective screening mechanisms.”

Model of access
To place its expertise at the disposal of jewellers, SGL has developed a lab service model in which jewellers do not have to bother about the logistics of transporting jewellery to and from the lab. SGL’s model aims to reduce the cost and turnaround time of certification. This service is available across India as well as in Dubai and Saudi Arabia, and a mark of its success is that SGL provides fair-value appraisals to customs authorities in Saudi Arabia.

Keeping up, going forward
As synthetic diamond producers benefit from advances in manufacturing technology, SGL works to stay ahead of the curve. The company regularly upgrades its V6 screening machine to meet real-world analysis needs.

“We are extremely pro-active on that front,” says Soni. “At the moment, the nano-polycrystalline diamond (NPD), a type of lab-grown gem, is hitting headlines because its features are so similar to those of the natural diamond. It’s in a very nascent stage, but we are researching that as well.”

Key stakeholders of the global diamond industry are becoming strict about due diligence before any uptake of diamonds, says Bandukwalla. This is why SGL’s V6 machine is poised to play a greater role in maintaining supply chain integrity — especially, she adds, in the screening and disclosure of lab-grown diamonds in the star melee category.

— Niladri S Nath, The Retail Jeweller News Service