Mumbai: The Gemological Institute of America has banned five Indian companies from further submissions to its grading lab, alleging they inscribed diamonds with GIA report numbers not associated with those gems, reports jckonline.

“We reasonably suspect that stones submitted under your client account, and other accounts for which we believe you to be partnered, have been inscribed with preexisting GIA report numbers that were not issued for the particular stones being submitted and that GIA did not inscribe,” said the letter from lab director Tom Moses to a principal of Surat-based Cristy Gems. “This has occurred on a number of occasions, indicating a pattern of intentional conduct.”

Four other companies received similar notices, it said. This letter “serves as notice that GIA is closing the accounts referenced below and will no longer accept any items for servicing from you or your company,” it continued. “All stones in-process will be returned ungraded.”

An email to the recipient was not returned. GIA did not return a request for comment at press time. Diamond Manufacturers & Importers Association president Ronald Vanderlinden said he “appreciates that the GIA is identifying possible abuses and is putting them out there for people to be aware” and will circulate the letter to his members.

He adds that his group considers falsely inscribing a stone a criminal act. In related news, the Bharat Diamond Bourse has suspended a Mumbai-based company and four of its directors for allegedly “dealing in lab- grown synthetic diamonds without making the necessary disclosures in respect of the same.”