The buyer is a partnership between Petra itself and the South African subsidiary of Stargems Group, an international and vertically integrated diamond company, which will cut and polish the stones.
Type II diamonds are found less frequently and are more valuable than Type I diamonds, as they have no measurable nitrogen impurities.
“We are delighted that both stones will be manufactured in South Africa, and it is fitting that we will be working with Stargems, who specializes in the sourcing and supply of the finest diamonds to customers across the world,” chief executive Richard Duffy said in the statement.
Petra fetched in March $12.2 million for a 299.3-carat Type IIA white diamond. That meant it obtained $40,701 per carat, which exceeds the $34,386/ct received for the 424.89-carat “Legacy of the Cullinan Diamond Mine” in May 2019.
Type II diamonds are found less frequently and are more valuable than Type I diamonds, as they have no measurable nitrogen impurities. This gives them exceptional transparency and brilliance.
Type IIb blue diamonds are so rare that their age has not been established. Recent studies on minerals trapped inside these diamonds imply that they are among the deepest-formed diamonds ever found, created at depths in excess of 500km below the Earth’s surface.
Cullinan is known as the birthplace of the famed 3,106-carat Cullinan diamond, which was cut to form the 530-carat Great Star of Africa.
It’s also the world’s most important source of blue diamonds, such as the 39.34-carat stone Petra found in April and which sold for $40.2 million last month. It was the company’s highest price ever for a single stone.
