Belgian Lab Detects Diamond with Fake Inscription

The diamond bearing the fake GIA inscription.

HRD Antwerp recently discovered a fake inscription on a polished diamond the lab had received for grading.

The 1.50-carat stone had a Gemological Institute of America (GIA) laser inscription corresponding to a natural grading report, HRD said Monday. The accompanying report listed the diamond as natural, with no color treatments. The stone was further identified as type IIa, meaning it contained virtually no elements other than carbon. However, during testing, the Antwerp lab found that the diamond had undergone High Pressure-High Temperature (HPHT) color treatment.

Although the diamond’s carat weight, color and cut precisely matched the GIA report, HRD noticed inconsistencies with clarity characteristics that were quite similar to those listed in the certification and could easily be mistaken during a standard loupe inspection, it explained.

“Detailed microscopic investigation by an experienced grader revealed that this was not the same diamond described in the report,” HRD said. “The clarity characteristics did not completely overlap. Since these characteristics are a unique fingerprint of the diamond, the inscription was conclusively identified as false. The diamond at hand had been intentionally inscribed with a fake laser inscription to deceive the customer.”

Correction: The story has been updated to clarify what was disclosed in the report and the findings of HRD.

Source: diamonds.net

Synthetic Diamond Fraudulently Inscribed To Match Natural Diamond Report

Fake GIA laser on synthetic diamond

Improvements in diamond growth technology and methods have led to a noticeable increase in colorless synthetic gem diamonds in recent years. Concerns in the diamond industry focus on laboratory-grown diamonds not being properly disclosed or even being sold as natural stones. Through careful examination and analysis, gemological laboratories can separate natural from synthetic diamonds. Occasionally, however, fraud is involved in attempting to conceal a gem’s identity. The Carlsbad laboratory witnessed such an attempt.

On this occasion, a round brilliant cut (figure 1, left) was submitted for an updated diamond grading report. Its girdle was inscribed with an actual GIA report number issued in 2015 (figure 1, right). The older report was for a natural, untreated diamond and contained the following grading information: 1.74 ct, round brilliant cut, D color, Excellent cut grade, and VVS1 clarity. Upon grading, the new submission was described as a 1.76 ct round brilliant cut with F color, Excellent cut grade, and VS1 clarity. Moreover, our screening processes determined that the newly submitted sample needed additional testing to determine its origin. This examination revealed it to be an HPHT-grown synthetic diamond. Synthetic cuboctahedral growth structure and phosphorescence were clearly visible in DiamondView imaging (figure 2).

DiamondView imaging of synthetic growth structure and blue fluorescence.

Figure 2. DiamondView imaging showed the synthetic growth structure and blue phosphorescence typical of HPHT-grown synthetic diamonds.

Aside from the observed discrepancies in weight (1.74 vs. 1.76 ct), color (D vs. F), and clarity (VVS1 vs. VS1), FTIR spectra clearly showed that these were not the same diamond. The natural diamond from the original report was type Ia with aggregated nitrogen impurities, while the new one was type IIb with boron impurities (figure 3). Careful examination of the report number inscribed on the synthetic diamond revealed a font different from the one used by GIA, proving that it was not an authentic inscription.

FTIR absorption spectra of natural and synthetic diamond.

Figure 3. FTIR absorption spectra revealed that the synthetic diamond was type IIb, whereas the fraudulently inscribed report number referred to a natural type Ia diamond. The spectra are offset for clarity.

While most synthetic diamonds that come to the laboratory are properly disclosed, some are submitted out of concern that a stone presented as natural might be synthetic. Rarely do we encounter the type of blatant fraud described here. It is important for the industry and public to exercise caution, because these types of misleading practices do occur. We believe the submitting client noticed inconsistencies with the GIA report information and sent it to the lab for an updated report. If any doubt exists or some aspect of a diamond (such as an inscription) seems odd, the stone should be sent to a gemological laboratory for verification.

Source: GIA Education