RAPAPORT… Gemological Science International (GSI) has launched a new grading report for synthetic diamonds that states whether a stone has been through post-growth treatment, claiming to be the first major laboratory to offer this.
The LGX Complete certificate will specify whether the stone was created using High Pressure-High Temperature (HPHT) or chemical vapor deposition (CVD), GSI said last week. It will also clarify whether the diamond is “as grown,” meaning it hasn’t been treated or enhanced.
“Consumer confidence is key, and consumers want more information and complete transparency about the natural and lab-grown diamonds they are buying,” noted GSI president Debbie Azar.
HRD Antwerp’s reports, which it updated last year to include a larger selection of color and clarity grades, do not contain either piece of information, based on sample reports available on its website. Certificates from the Gemological Institute of America (GIA) include a note on whether the diamond was created using HPHT or CVD, but state they “may” include post-growth treatments.
Image: A lab-grown rough diamond. (Shutterstock)
GSI to Flag Treatments in Lab-Grown Reports
The Bottom Line
- GSI's LGX Complete certificate specifies the growth method (HPHT or CVD) and indicates if the lab-grown diamond is untreated or post-growth treated.
- This initiative marks GSI as the first major lab to explicitly disclose post-growth treatments in synthetic diamond reports.
- Other labs like HRD Antwerp and GIA provide some growth method information but do not consistently report post-growth treatments.
Summary by Rapaport AI
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