The type IIa, cushion-modified brilliant synthetic stone was submitted to the Gemological Institute of America’s (GIA) Hong Kong laboratory for grading.
It was of J-equivalent colour and VS2-equivalent clarity grade, which was said to be comparable to a high-quality natural diamond.
Although it was not disclosed as synthetic, a GIA statement noted the laboratory was able to identify it as having been created via chemical vapour deposition (CVD) technology using its standard screening and testing procedure.
According to the statement, black inclusions, often contained in synthetic diamonds, were not found in this particular stone, which meant it could have been mistakenly identified as natural had it been examined solely by microscope.
“This case therefore highlights the importance of using advanced spectroscopic instruments as well as conventional gemmological techniques to ensure an accurate identification,” the statement read.
Following testing, the synthetic was inscribed on the girdle with the report number and the words ‘Laboratory Grown’ in line with the GIA’s protocols for undisclosed synthetics.
The GIA statement also noted CVD technology had accelerated in recent years, producing large, high-quality and colourless and near-colourless synthetics. It added that more high-quality samples, both in terms of size and clarity, were expected to be examined in the future.
This follows news earlier in the year where the GIA tested two CVD diamonds – one weighing 2.51 carats and the other weighing 3.23 carats.
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