An important fancy green and pink diamond ring set with a modified brilliant cushion-cut natural fancy green diamond weighing app. 1.16 ct. encircled by numerous brilliant-cut natural pink Argyle diamonds weighing a total of app. 0.37 ct. flanked by brilliant-cut white diamonds weighing a total of app. 0.53 ct., mounted in 18k pink and white gold. Colour: Top Wesselton (F). Clarity: VVS. Green diamond with inscription GIA 5201651754. Size 54. Tokyo, Japan, circa 2019.
Cut Grade of white diamonds: Triple excellent-cut. Hearts & Arrows.
Accompanied by GIA certificate no. 5201651754 indicating, “Natural Fancy Grayish Green. Even”. New York, 2020.
Colour distribution: Even.
Among fancy-colour diamonds, natural-colour green stones with saturated hues are some of the rarest and most sought after. These diamonds are coloured either by simple structural defects produced by radiation exposure or by more complex defects involving nitrogen, hydrogen, or nickel impurities. Most of the world's current production of fine natural green diamonds comes from South America or Africa. Laboratory irradiation treatments have been used commercially since the late 1940s to create green colour in diamonds and closely mimic the effects of natural radiation exposure, causing tremendous difficulty in gemological identification. Compounding that problem is a distinct paucity of published information on these diamonds due to their rarity. Four different colouring mechanisms - absorption by GR1 defects due to radiation damage, green luminescence from H3 defects, and absorptions caused by hydrogen- and nickel-related defects - can be identified in green diamonds. Careful microscopic observation, gemological testing, and spectroscopy performed at GIA over the last decade allows an unprecedented characterization of these beautiful natural stones. By leveraging GIA's vast database of diamond information, they have compiled data representative of tens of thousands of samples to offer a look at natural green diamonds that has never before been possible.
It took GIA New York six months to test the diamond and write the natural coloured diamond report. Because the diamond's colour has been obtained from natural radiation, the stone had to be tested by GIA in the rough state, after shaping and again after polishing. Three times in all, to ensure the colour is stable. GIA New York is the only laboratory in the world that is able to test natural green diamonds.