The Gemological Institute of America (GIA) issued a fraud warning after three diamonds bought in Johannesburg, South Africa, were reported to have been sold with forged grading reports. After examining the diamonds, weighing 3 carats, 4.08 and 5.01 carats, it was revealed that at least one of the stones was treated with high pressure/high temperature (HPHT). According to the GIA, the problem is not believed to be widespread and is limited to a small number of stones.

After discovering the fraud, an investigation was launched by the GIA, South African Industry leadership and the client to whom the stones were sold. As a result, at least one person was arrested.

"GIA cooperates fully with law enforcement agencies worldwide to help prevent, detect and prosecute these activities,” said Tom Moses, senior vice president of GIA Laboratory and Research. “It is critical for the trade and our public benefit mission that GIA protect the gemological standards our grading reports have set for more than 50 years. We are committed to maintaining the highest level of integrity in our reports to ensure consumer confidence."

Moses went on to explain that "Authentic GIA reports include a number of important security features, some apparent and others more subtle."

Reports issued after January 1, 2000, can be cross checked online to confirm that the data in the written report matches the data issued by the GIA.  Customers can also submit their stones with their certificate to a GIA laboratory where the stone and report are examined to make sure they match. Additionally, customers can update their report, meaning the diamond goes through a full grading process — including tests for different treatments and a new report is issued.