Petra Diamonds has announced the recovery of an exceptional 41.82-carat Type IIb blue diamond from its Cullinan Mine in South Africa, a source long associated with some of the world’s most important blue diamonds.
Noted for its striking colour and clarity, the stone reinforces Cullinan’s reputation as a rare producer of high-quality blue diamonds, many of which have achieved record price-per-carat levels at international auctions.
According to the Natural Diamond Council’s Fancy Colour Diamonds report, Type IIb blue diamonds represent only a minute fraction of global diamond output. Formed more than 500 kilometres beneath the Earth’s surface, far deeper than most diamonds, their blue hue is caused by trace amounts of boron. Their scarcity has translated into strong long-term performance, with data from the Fancy Color Research Foundation showing blue diamonds have appreciated by +242% since 2005.
Commenting on the recovery, Raluca Anghel, Head of External Affairs and Industry Relations at the Natural Diamond Council, said: “Blue diamonds are prized for their extreme rarity and enduring value, but their importance extends far beyond the gemstone itself. On average, around 80% of the value generated by responsible diamond recovery is retained locally, supporting jobs, infrastructure, healthcare, education, and vital social programmes, while also contributing significant tax and royalty revenues to national economies. Discoveries of this calibre therefore carry profound meaning not only for the global diamond industry, but for the communities and countries that benefit directly and indirectly from their recovery.”