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  • 2.OpenCV software was used to draw perfect circles from the centre of the ring, marked by a green dot.
  • 1.The 4.04-carat ring fashioned from a single-crystal CVD lab-grown diamond.

GIA Examined Solid Lab-grown Single-crystal Diamond Ring



The Gemological Institute of America (GIA) recently has examined a 4.04-carat single-crystal lab-grown diamond ring (image 1). The 3.03 mm thick band had an inner diameter of 16.35–16.40 mm and an outer diameter of 20.32–20.40 mm. The ring was produced by Dutch Diamond Technologies in collaboration with the Belgian jewellery store Heursel, established in 1745.


This lab-grown diamond ring was cut from an 8.54-carat plate grown by chemical vapor deposition (CVD). Laser cutting produced a near-perfect circular ring, as demonstrated using digital imaging analysis to measure its inner and outer circumferences (image 2).


According to GIA, manufacture of a solid single-crystal diamond ring is a very complex and challenging process. Once material is removed from the crystal, very fine fractures and imbalanced strain can have severe consequences and the ring can shatter. Processing can take more than six months. Creating the single-crystal lab-grown ring involved about 1,131 hours of processing (including pre-grinding) in the Dutch town of Cuijk, followed by 751 hours of polishing in Belgium.


The solid lab-grown diamond ring was studied by GIA and specified with a VVS2 clarity based on dark non-diamond carbon pinpoint inclusions (growth remnants typical of CVD-grown diamonds) with good polish (polishing on the interior surface of the ring precluded very good). Although the ring is a near-perfect circle (image 2), symmetry was considered not applicable. The diamond has a high colour based on GIA’s colour grading scale. The ring was laser inscribed “Laboratory-Grown” on a side facet.


The quality and size of this solid diamond ring are a great example of the advancing technology in lab-grown diamonds and changing trends in the jewellery industry. This is the first time a GIA laboratory has examined a colourless diamond ring fashioned entirely from a lab-grown diamond, said the lab. (Photo courtesy: GIA)





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