(IDEX Online) - A grading lab in Italy has issued a fraud warning after three one-carat diamonds, all submitted on the same day, were found to be CVD lab growns.The stones, all round brilliant F / VS1, were all accompanied by paper GIA grading reports from different dates in May 2023 which described them as natural.The weights, dimensions and GIA inscriptions all appeared to match, but there was a clear anomaly when they were exposed to UV light to detect fluorescence."The stones in question were absolutely inert, whereas the GIA documents described the fluorescence as 'faint'," said Gem-Tech, based in Marcianise, Southern Italy. Spectrophotometric analysis confirmed they were lab grown."The discrepancies, however slight, in the proportion measurements and fluorescence detection, together with the undisputed prestige and competence of the American Institute, support the assertion that the stones examined by Gem-Tech are not the stones present on the GIA online platform," the lab said.It said it was not the first time it had encountered this type of apparent fraud, and warned that cloning a document by forging the type of paper backing and authentication systems is not particularly complex."The technology to laser-engrave any logo is now available to many, making it less secure. As a result, new, more sophisticated systems are appearing on the market. "These systems are virtually impossible to counterfeit because they are based on laser inscription beneath the surface of the diamond."Pic of a GIA inscription on on of the stones, courtesy Gem-Tech