South Africa finds a rare blue diamond that has caught the attention of the global gemstone market. Nduka Uzuakpundu writes
It was just natural the glee and near-broad smile on the face of South Africa’s president, Cyril Ramaphosa, at a public forum, recently, in Pretoria, when he showed, to gushing applause, a rare find: a 42-carat, blue diamond that mineral specialists at the Johannesburg Stock Exchange (JSE) valued at $40 million.
The immediate fact about the blue diamond is: it is remarkable for its high carat weight. That also makes it the darling of the members of the International Jewellers’ Association, who trade worldwide, in the hardest known mineral.
The diamond was discovered at the historic Cullinan Mine in Pretoria, South Africa’s administrative capital. An interesting aspect of the find is that it is classified as a Type IIb gem and belongs to an elite category that represents less than 0.1 per cent of all natural diamonds worldwide. It is widely held by traders and stone buffs alike that blue diamonds are among the most sought-after gemstones globally, prized for their extreme rarity and unique scientific qualities, including electrical conductivity. One report said that the extraordinary 42-carat stone is set to be showcased at a major international auction later this year, where it is expected to attract global attention.
No date or venue for the auction has been slated. However, most auctioneers and investors in the diamond trade believe it would be Antwerp, Belgium, the headquarters of the World Diamond Council (WDC).
Ever since the rare stone, just a little bigger than a table tennis ball, was unearthed in December 2025, Pretoria has come under global spotlight, with special attention paid to the Cullinan mine. While auctioneers in the European Union and North America are busy honing their skills to advertise the 42-carat blue diamond to prospective buyers, feelers from Antwerp as January came to an end suggested that unidentified individuals were offering between $65 million and $82 million for the mineral. As in the art world, where faceless, wealthy individuals – some of them close to leading world galleries or royal families – smile away after paying behind the scene for highly-prized paintings, or in the entertainment industry, where a guitar used by John Lennon, or, again, the piano used by Aretha Franklin – the undisputed Queen of Soul Music – so it is at the global diamond emporium. It’s all capitalism and commerce at a confluence of public demand and supply curve!
It won’t be a surprise if South Africa’s rare stone is carted home by an unmasked buyer. Whatever happens, the rare stone has come with some tidy experience for South Africa: De Beers, a global leader in everything diamond, a British-owned, 138-year-old mining firm set up by a business mogul, Cecil Rhodes, in 1888, is widely rumoured to have earmarked nearly $570 million for Pretoria’s mining sector for the next four years.
That, in itself, is likely to draw other investors from outside South Africa. Industry analysts project that a flood of tourists, traders, and investors in the diamond market from India, Australia, Canada, the United States of America, the European Union, and more would soon fly into South Africa to visit the Cullinan Mine.
Hoteliers, cab operators, and currency traders are fast calculating the extent to which the 42-carat diamond find would be a booster to their business.
Although the rare find is indeed being celebrated in South Africa and beyond, Ramaphosa complained, quite visibly, recently, amid all that, about two things: streaming phone calls and text messages from political allies, and a group of seventeen financiers, who identified themselves as “The Gem Cartel,” based in Kolkata, India.
One report says the Cartel has offered nearly $90 million upfront for the 42-carat stone, pronto. It intends to preempt the planned auction of the rare diamond. For its reputation, Cullinan is less likely to allow that. As one writes, Pretoria is under ambitious pressure from the WDC, an organization representing the entire diamond value chain, as well as representatives from diamond mining, manufacturing, trading, and retail, to follow the extant protocol of exhibition and auction of unique stones, like the 42-carat diamond, at designated
International Emporium – oftentimes in Belgium.
WDC president, Feriel Zerouki, a woman from the United Arab Emirates, insisted that exhibitions and auctions are lawful aspects of transparency in the diamond trade. Even at $160 million from any individual or corporate entity outside exhibition and auction, the South African government would do well to subject the 42-carat diamond to clean bidding in the international market.
That position has the backing of the International Diamond Manufacturers Association (IDMA) and the World Federation of Diamond Bourses (WFDB).
Ramaphosa is gratified, nonetheless, that the rare stone is not a gem of war; that it is a clean, natural mineral extracted from the bowels of Mother Earth, and that it has passed a punctilious vetting by the Kimberley Process Certification Scheme (KPCS).
“The KPCS was established under United Nations General Assembly Resolution 55/56. Following recommendations by the Fowler Report in March 2003, the process was set up to ensure that diamonds purchased were not financing violence by rebel movements and their allies . . .” – as in Sierra Leone and Liberia, in the two neighbouring West African countries’ fratricidal wars in the late 1980s and a greater part of the 1990s – “seeking to undermine legitimate governments.”
Diamond mining plays a leading role in South Africa’s political economy. Available records reveal that back in 2003, it contributed billions in sales and employed over 15,000 people.
The Cullinan Diamond Mine (formerly Premier Mine), where the 42-carat stone was discovered in an underground diamond mine in the town of Cullinan, is 40 kilometres (25 miles) east of Pretoria, Gauteng Province.
Wikipedia records that it was established in 1902 and has a carrot-shaped volcanic pipe, with a surface area of 32 hectares (79 acres).
The mine rose to prominence in 1905, when the Cullinan Diamond, the largest gem-quality rough diamond ever found, weighing 3,106 carats (621.2 grams), was discovered there.
The mine – the only significant source of blue diamonds in the world – was established by Thomas Cullinan and has produced over 250 stones that are greater than 100 carats (20 grams) and more than a quarter of all the world’s diamonds that are greater than 400 carats (80 grams)
