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Graff buys $17.5 million 373-carat rough diamond, once part of the unsold Lesedi La Rona

Sarah Royce-Greensill
The 373.72-carat rough diamond purchased by Graff is believed to be a fragment of the Lesedi la Rona

This time last year there was an intense buzz around a diamond. Not just any old diamond – this was a 1,109-carat rough stone dubbed Lesedi La Rona: the second-largest gem-quality diamond ever discovered, which had been found in Botswana’s Karowe mine in November 2015. And in a world first, it was being auctioned publicly, in a specially staged and much-publicised auction held at Sotheby’s last June, with an estimate of $70 million.

Unfortunately for Sotheby’s, the diamond trade didn’t take kindly to an auction house muscling in on its incredibly private industry, one that’s cloaked in centuries of tradition, and the auction was a flop. Bidding stalled at $61 million, less than the undisclosed reserve price, and the diamond didn’t sell. Sotheby’s hastily withdrew the stone from the public eye, with assurances that there was plenty of interest in it and that it would be sold to a private collector. 

The 1,109-carat Lesedi La Rona rough diamond Credit:  Donald Bowers/Getty Images

As yet it's not known what happened to that colossal stone - but it appears that the rough diamond could have been even bigger. A further 373.72-carat rough diamond was found in the same piece of kimberlite as the Lesedi La Rona and, when recovered, the two stones fit exactly into each other, like a jigsaw. And it has now been revealed that the smaller fragment has been purchased by Laurence Graff, founder of Graff Diamonds, for a sum of $17.5 million (£13.5 million). 

The rough diamond was the largest out of 15 single rough stones offered in the 'Exceptional Stone Tender' staged by Lucara Diamond Corp, the company that owns the Karowe mine, last Thursday. Totalling 1,765.72 carats, overall the sale achieved $54.8 million (£42.4 million), with seven of the 15 stones selling for over $2 million.   

Announcing its purchase this week, Graff said that the 373.72-carat D-colour, Type IIA rough diamond “has the potential to yield a significant polished stone”.

If anyone has form in this area, it’s Graff. The house has built its reputation around acquiring, cutting and polishing sizable diamonds. In 2006 it bought the Lesotho Promise, a 603-carat rough diamond, which it cut into 26 D-Flawless diamonds totalling 224 carats, including a 75-carat pear-shaped diamond. In 2008 it cut a 493-carat diamond into 20 different stones.

The Graff Venus, a 118.78-carat, Flawless D-colour diamond

Last December the house unveiled the 118.78-carat Graff Venus, the world’s largest D-colour, Flawless heart-shaped diamond that was cut from a 357-carat rough. Other notable stones in the house’s history include the Delaire Sunrise, a 118-carat Fancy Vivid Yellow diamond that was cut from a 221.81-carat South African rough; the Graff Pink, a 23.88-carat pink diamond that Graff re-cut to improve its colour and colour; and the 102.79-carat Constellation, the largest round, D-colour, Internally Flawless diamond ever to be graded by the Gemological Institute of America.

It remains to be seen what exactly Laurence Graff will choose to do with this particular rough. “Graff will now embark on the process of studying and analysing the stone before beginning the cutting and polishing process,” said the company in a statement. The jeweller will spend several months scanning the stone with state-of-the-art lasers and using computer modelling to come up with various different size and shape combinations before even beginning the painstaking process of cutting and polishing. Typically it can take over a year to turn a large rough diamond such as this one into a finished jewel.

The worlds most expensive gemstones, in pictures

Usually, a gem-quality rough diamond will yield a polished stone of a maximum of 45-48 per cent its weight – meaning we could expect to see diamond of around 167 carats emerge from this rough, if Graff chooses to cut a single, polished stone. Alternatively, he may choose to maximise the yield by cutting several stones, which may be used in different pieces of jewellery or kept together – such as the Eternal Twins, the identical 50.23-carat emerald-cut stones that came from the same 269-carat rough, which he set into earrings in 2016. Recently Chopard cut a collection of 23 diamonds from a 342-carat rough stone, which was also found at the Karowe mine, and set them into a parure of six jewels dubbed the Gardens of Kalahari.

Whatever the design, Graff has always prioritised the beauty of stones themselves, priding itself on perfection. The house caused controversy in 2010 when it shaved four and a half carats off the famous Wittelsbach-Graff blue diamond in order to improve its clarity from VS2 to Internally Flawless – the highest possible grade. So whatever comes out of this significant rough, we can be sure of one thing – it will be as close to perfection as possible.

graffdiamonds.com

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