Recently HRD Antwerp had come across near-colourlessrough lab grown diamonds that feature octahedral and other shapes that are characteristics or natural diamonds. This adds difficulties to visual identification of lab grown rough diamonds to less experienced traders.
Previously detecting lab grown rough diamonds was easier due to the typical cubo-octahedral shape displayed by HPHT (high pressure high temperature) diamonds and the characteristic plate structure of CVD (chemical vapour deposition) diamonds which differ significantly from the morphology of natural diamonds.
The rough melees examined by HRD Antwerp varied in size from 0.01 carat to 0.04 carat and were produced by Taidiam, a Chinese company offering both HPHT and CVD lab grown diamonds.
“A more in-depth investigation on a microscopic level however still reveals the remnants of a seed crystal used to position the precipitated carbon atoms, and / or other characteristics inherent to lab grown diamonds. An infrared spectroscopy analysis by our research team has also demonstrated that all colourless diamonds included in the examination were found to be type IIa or type IIb,” explained Katrien De Corte, Chief Education Officer HRD Antwerp.
De Corte added that it would merely affect the rough trade “as once the diamonds are polished, dedicated equipment still provides a fool proof solution for identifying lab grown diamonds in our lab”.
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