Petra Diamonds Ltd (LON: PDL) (OTCMKTS: PDLMF) (FRA: FPO) announced the discovery of a remarkable 41.82-carat Type IIb blue diamond in South Africa last week.
The exceptional stone, unearthed at the company’s Cullinan Mine, is extremely rare. Only about 0.1 per cent of all natural diamonds throughout the world fall into this category.
The finding has bolstered the mining operation’s widely regarded status as the world’s top source for blue diamonds. Several have been discovered at this site, which can be viewed on the company’s website.
Petra’s social media post about the discovery received a whopping 1,186 likes on LinkedIn. The most any previous posting from the diamond miner had ever received was 232.
“The company is in the process of analysing the stone and ascertaining the preferred method of the sale of this stone,” Petra specified in the post. “Further announcements with regards to the marketing of this stone will be made in due course.”
The diamond could potentially fetch up to US$40 million at an auction because of its rarity and beauty. It is the largest of this quality that Petra has ever pulled out of the ground. In 2025, a 31.94-care blue diamond found at Cullinan went for US$21.5 million at an auction.
“What distinguishes this find, and why it matters to serious collectors and connoisseurs, is not only its carat weight, but what it represents: a reminder that the most exceptional natural diamonds emerge from geological conditions that are both ancient and nearly impossible to replicate,” said Armenian Jewellers Association Vice President, Sahag Arslanian.
Abroad, the precious gemstone compares to smaller polished world-class diamonds like the Oppenheimer Blue (14.62 carats), sold for US$71.3 million in 2016; and the Blue Moon of Josephine (12.03 carats) which went for US$48.4 million in 2015.
Petra’s new find sticks out as what may be the largest high-grade fancy blue rough in modern times.
Another one of the diamonds discovered at Cullinan in 1905, a 3,106-carat transparent stone, is part of the British Crown Jewels. Petra acquired the mine site from De Beers in 2008.
Read more: NevGold’s latest discovery represents near-term antimony production potential
Follow Rowan Dunne on LinkedIn
rowan@mugglehead.com
