Editor’s Note
This article details the discovery of an exceptionally rare oval diamond, notable not only for its size—larger than a quail’s egg—but also for its supreme quality. Graded D color, flawless, and Type IIa, it represents the pinnacle of brilliance and purity in gemology.
At a Sotheby’s Hong Kong auction held on October 5, a 102.39-carat, highest-grade oval diamond was won by a Japanese collector for approximately HKD 121 million (about JPY 1.7 billion). This collection was offered in an unprecedented single-lot live auction (with no reserve price), starting online at HKD 1 (about JPY 14). This diamond is over 100 carats, D color (completely colorless), Flawless, and also rated Excellent in cut, polish, and symmetry. It is a rare Type IIa diamond, composed solely of carbon containing no nitrogen impurities, which accounts for less than 2% of all diamonds.
The diamond originated from a 271-carat rough stone mined in 2018 at the Victor Mine in Ontario, Canada. It was meticulously cut and polished over more than a year of research by Diacore, a top diamond polishing and sourcing company. To date, only eight white diamonds over 100 carats, D color, and Flawless or Internally Flawless have been sold at auction, six of which came from Diacore.
In a Sotheby’s Hong Kong auction held last April, a Japanese collector also won an 88.22-carat, D color, Flawless, Type IIa oval diamond for HKD 108 million (about JPY 1.542 billion).