The terms “synthetic” and “cultured” have been so widely used in the marketing of man-made diamonds that the many consumers do understand the difference between these laboratory-grown diamonds and natural diamonds. In an effort to be clear about the proper disclosure and communication of the synthetic origin of these diamonds, the EGL USA group has revised their diamond grading reports.
- The EGL now uses the term “laboratory-grown” to disclose the synthetic origin of the diamond.
- EGL USA gemological reports for synthetic diamonds have a new gray color theme to distinguish them from the dark blue scheme for natural diamonds.
- Synthetic diamonds have a mandatory laser inscription that includes the term “lab-grown” (or its equivalent), the manufacturer (if known) and the EGL USA report number.
- The back cover of the new synthetic report features information about the different synthetic manufacturing processes, detection techniques, and grading methods.
- The report identifies the type of synthetic origin: High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD).
- The report identifies the color origin: As Grown or Enhanced (HPHT or irradiation)
- The report contains an identification section that indicates long-wave and short-wave fluorescence, microscopic features, and diamond type.
From the time that HPHT treated diamonds entered the gemstone marketplace in 1999, the EGL USA has continued research efforts to develop reliable detection and identification procedures for HPHT diamonds.