Image: Karowe mine at dusk – Lucara Diamonds

We are making history,” states HB Antwerp. At their office in the Antwerp diamond district, the third largest rough diamond ever was delivered earlier this week. It was dug up in the Karowe mine in Botswana,. A unique stone of 1,174 carats, although it was originally 2,500 carats. The diamond is in Antwerp for analysis. Before it is polished, it will go on tour.

It seems like a normal Monday morning on the Hoveniersstraat. There is an international crowd, though. Between the people, three armed security guards come walking. The middle one is carrying a small, sturdy black, plastic case. They enter the office of HB Antwerp.

Inside the case is the third largest diamond ever. It weighs no less than 1,174 carats, or 234.8 grams.
Three men, the three partners of HB Antwerp, are sitting at the ready. This diamond company has an appointment with Lucara, a Canadian company that runs the Karowe mine in Botswana. The mine has been supplying remarkably large stones for several years.

Antwerp world center

Several precious stones from the mine have already come to the company HB Antwerp. Just last year the Sew√™lo, at 1,758 carats the largest remaining rough diamond in the world. “We are playing in the Champions League here,” says spokesperson Margaux Donckier. “Nowhere do they have the equipment to analyze and polish the largest diamonds in the world.

Then the time is ripe. A clear plastic bag is opened, containing a box and delivery note. Director of Operations at HB Antwerp, Boaz Lev, meticulously checks the receipt. He signs off, opens the box and sees five individual bags, with visibly large stones.

The largest stone is brought out first. About a month and a half after it was mined, it still has no name and a drab black exterior. A bright LED lamp is placed against the stone. Immediately the stone lights up. The black color is caused by remnants of the rock, the kimberlite from the mine.

Exceptional stone

This is super exciting. It’s really an exceptional stone,” Rafael Papismedov says even a little coolly. “Very few diamond dealers, who have been working for generations, have ever seen a stone like this. A very large part of the stone is extremely white. The black still casts a shadow.

By comparison, the Cullinan from South Africa was once the largest diamond in the world, accounting for 3,106.75 carats (621.35 grams). It was broken down into smaller stones. Some were incorporated into the British crown jewels.

In 2016, the Lesedi La Rona (1,111 carats) also came to Antwerp from the Karowe mine. That stone was sold for about 45 million euros. What is this stone worth? “That’s hard to say. A few million to tens of millions? We hope the latter of course,” Papismedov says. “We won’t know that until we have analyzed the stone very well. If we can get two hundred 1-carat stones out of it, it’s not that much. If you can extract a few very large stones, then the value is exponentially greater.

Abandoned mine turns out to be super mine

The five bags actually contain the complete stone, which broke into pieces during production. “Originally the diamond was about 2,400 carats. Lucara may have the most modern techniques in the world to use x-ray scanning to spare the stone as much as possible during the crushing process, but because of the size of the stone, it is still very fragile and so sometimes parts do detach.

Remember, before Lucara bought the Karowe mine, it was about abandoned. Back then stones were still crushed into smaller pieces. The latest technique saves most of the stone, so more exceptional stones are found,” Papismedov says.


The stone will certainly be polished. For that, it must first be analyzed for four to six months. The polishing is planned for the beginning of next year at the earliest. We are told: “Best not to drop it, because then we will have more pieces.” In the meantime, the stone is – yes – going on tour. A first stop in New York has already been set. A number of exclusive prospective buyers may get to see the stone. Because that also marketing also determines the price of diamonds, the partners agree.