Keeping lab-created diamonds separate from their natural counterparts is an ongoing challenge for the diamond trade. In its 2021 Laboratory-Grown Diamond Guidelines, the World Jewellery Confederation (CIBJO) instructed companies to have “robust detection protocols [and use] diamond verification instruments” to avoid mixing synthetics in with natural stones. As the industry steps up efforts to differentiate the two segments, the market for lab-grown-detection equipment is thriving.
These verification devices can identify natural diamonds, synthetics and simulants, and refer stones of unknown origin for further analysis. While some focus only on loose goods, others can test mounted stones in finished jewelry as well. A common detection method is to scan for type II stones, since all colorless lab-grown diamonds fall into this category, compared with just 1% to 2% of natural ones. Using tools such as fluorescence or infrared spectroscopy, the devices separate out all the type II diamonds and refer them for further testing to determine if any are natural.
Helping business owners choose the most suitable instruments for their products has been a focus of the trade recently.
“There is an overwhelming choice of devices available,” says Julia Griffith, founder of online education platform The Gem Academy, where she offers a course on lab-grown. “The biggest challenge for many is knowing which equipment would suit their own needs best.”
Rest assured
In June and July, the London Diamond Bourse (LDB) hosted a six-week event in collaboration with the Natural Diamond Council (NDC), showcasing a selection of synthetic-detection devices from multiple manufacturers. All of the instruments had gone through the NDC’s Assure Program — an independent testing regimen that rates the effectiveness of the detection machines on the market. One of the factors Assure assesses, for instance, is a device’s “diamond false positive rate” — the percentage of lab-grown stones or simulants it mistakenly classifies as natural. The optimal rate for that, of course, is zero. Machines that have achieved this milestone include the GIA iD100, De Beers’ DiamondSure system, the Gemlogis Belize, and Yehuda’s Sherlock Holmes, according to the Assure website.
One notable area of development is the Assure Sample — the selection of natural stones, synthetics and simulants that the program uses as a baseline for testing the devices’ accuracy. The NDC recently updated the Assure Sample with “synthetic diamond materials that are not yet on the market,” according to the trade body’s CEO, David Kellie. “Having a challenging sample allows us to differentiate between the instruments and to anticipate their capability to detect potential commercial synthetic-diamond developments.”
Staying ahead of evolving diamond-growing technology means being proactive rather than reactive, affirms Thomas Gelb, technical advisor to the Assure project. “A lot of experimentation on…diamond growth methods is being done openly at the university level. [As a result,] we can predict with some degree of accuracy what changes to growth are possible, and [can] thus create samples prior to their introduction into the market.”
‘Increasingly sophisticated’
Equipment manufacturers are looking ahead as well.
“The technology and the number of accessible machines [have improved by] leaps and bounds over the last two years,” says LDB president Alan Cohen. “I think a reliable testing machine will become as commonplace as a digital scale in any organization that deals in diamonds and diamond jewelry.”
Of course, the effectiveness of a device still depends, to some extent, on the user’s knowledge. “Some of the screeners that have been developed are easy to use and will refer 100% of laboratory-grown diamonds when used correctly,” says Griffith. “Others require analysis by the user, who must then [reach] a conclusion.” For this reason, retail jewelers and brands are investing in both equipment and education, she reports, declaring that “this empowerment is wonderful to see.”
Overall, the future for lab-grown detection seems bright. “Today, we are looking at well-informed buyers having access to an increasingly sophisticated group of instruments,” says Kellie. “This puts our industry in a great position going forward.”
Image: Natural Diamond CouncilArticle from the Rapaport Magazine - September 2022. To subscribe click here.