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Record-Breaking 34.59ct. CVD Diamond Analyzed at GIA Hong Kong Lab May 08, 2023 (0 comments)


Hong Kong--The Gemological Institute of America (GIA) Hong Kong laboratory recently analyzed its largest-ever chemical vapor deposition (CVD) gem diamond, showcasing significant advancements in CVD growth technology.

[Photo by Johnny (Chak Wan) Leung via GIA]

Per a report by GIA., the 34.59 ct emerald-cut diamond, measuring 24.94 x 13.95 x 9.39 mm, was produced by Ethereal Green Diamond in India and featured G color and VS2 clarity.

The report adds that small black graphite inclusions were found within the diamond, and microscopic observations revealed weak oily or wavy graining, a characteristic sometimes seen in CVD diamonds. Infrared absorption spectroscopy detected no absorption related to nitrogen, but a weak absorption related to boron was observed. Photoluminescence (PL) spectroscopy confirmed that the diamond was annealed under high pressure and high temperature (HPHT) to improve its color appearance.

The report noted that DiamondView fluorescence imaging displayed green and blue colors with a banded pattern, indicating at least eight growth steps to achieve the diamond's size.

This milestone in CVD diamond growth highlights the rarity of mined diamonds with comparable size and quality.

GIA said in the report that it will continue to monitor advancements in gem diamond growth technology to ensure accurate identification in its laboratories.

Learn more in this GIA report.

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