It could easily have been mistaken as natural.
Gemological Institute of America Inc. has identified a 5.19-carat undisclosed lab-grown diamond.
The stone was “the largest CVD synthetic diamond GIA has examined to date, and the largest reported in the jewelry industry,” according to GIA. CVD stands for chemical vapor deposition.
The cushion modified brilliant diamond measuring 10.04 millimeters by 9.44 millimeters by 6.18 millimeters was submitted to GIA’s Hong Kong laboratory for grading service.
According to GIA, the diamond “had J-equivalent color grade and VS2-equivalent clarity, comparable to a high-quality natural counterpart.”
The organization also explained: “It is worth noting that black inclusions, often contained in synthetic diamond, were not found in this CVD specimen, which could have been mistakenly identified as natural based on microscopic examination alone. This case therefore highlights the importance of using advanced spectroscopic instruments as well as conventional gemological techniques to ensure an accurate identification.”
A GIA Identification Report was issued and the stone was inscribed on the girdle with the report number and the words “Laboratory Grown,” following GIA’s protocols for undisclosed synthetics.
Two samples over 3 carats were reported in early 2016 as the largest chemical vapor deposition synthetics.
In September, the institute also examined a 10.08 carat synthetic diamond produced using the high pressure/high temperature (HPHT) method. This is the largest HPHT synthetic diamond GIA has examined.
Read more from GIA.
This 5.19-carat CVD synthetic diamond (10.04 × 9.44 × 6.18 mm, with J-equivalent color and VS2-equivalent clarity) is the largest GIA has identified to date. Photo by Johnny Leung and Tony Leung.