Largest diamond discovered in a decade fails to sell at auction

The world’s largest rough diamond found in a decade has failed to sell at a London auction after bids did not reach the minimum reserve price.

The 1109-carat ‘Lesedi la Rona’ – the largest rough diamond in existence today – was uncovered by diamond production firm Lucara in November 2015 at its Karowe mine in Botswana.

The tennis-sized diamond was expected to sell at the Sotheby’s auction for $70m (£48m), but the highest bid was around £45m ($61m).

A study by the Gemological Institute of America (GIA) found the diamond’s top colour and transparency “exemplify” the limpid appearance commonly associated with type IIa diamonds.

Stones in this group are “the most chemically pure and often show extraordinary optical transparency”.

Speaking before the auction, David Bennett, worldwide chairman of Sotheby’s jewellery division, said the diamond was a “find of a lifetime” and added “every aspect of this auction is unprecedented”.