The 1,109-carat Lesedi La Rona, described as the largest gem-quality rough diamond in existence, was widely tipped to eclipse the auction world record for the most expensive rough or polished diamond, gemstone or jewellery piece ever sold.
As previously reported by Jeweller, the tennis ball-size stone was discovered by Canadian-based mining company Lucara Diamond Corp at its site in Karowe, Botswana, in November last year.
It went under the hammer at a Sotheby’s auction in London on 29 June where it was reportedly valued at US$70 million (A$94 m); however, the highest bid on the day was said to be US$51 million (AU$65 m).
Shares in Lucara reportedly fell 16 per cent the day after the failed sale.
The president and CEO of Lucara, William Lamb, issued a statement shortly after the auction that read, “…the company will be retaining the exceptional 1,109-carat type IIa Lesedi La Rona diamond as bidding did not meet the reserve price at the auction held this evening at Sotheby’s in London”.
Had it reached its reserve price, the Lesedi La Rona would have usurped a stone known as The Constellation as the most expensive rough diamond ever sold. Both were discovered by Lucara at the same mine within days of each other.
A Dubai-based diamond trading company purchased The Constellation, which weighed 812.77 carats, for US$63.1 million (AU$86.8 m) in May.
The Lesedi La Rona, or “our light” in the local Tswana language of Botswana, is a type IIa diamond. It is estimated to have been formed between one and three billion years ago at depths of more than 140 km below the Earth’s surface.
It is said to be second in size only to the 3,106-carat Cullinan diamond discovered in the Cullinan mine in South Africa in 1905, cuts of which form part of the British crown jewels.
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