Lesedi La Rona rough diamond fails to sell at auction

July 06, 2016

Lesedi La Rona rough diamond fails to sell at auction

The world's largest uncut diamond has failed to sell at a London auction after bids did not reach the minimum reserve price.

The Lesedi la Rona, almost the size of a tennis ball, was unearthed in Botswana in November.

The rough diamond is 1,109 carats and believed to be more than 2.5 billion years old.

It had been expected to sell for more than £52m ($70m) but the highest bid was about £45m ($61m).

The auction at Sotheby's was the first time a rough diamond of such a size has gone on public sale.

 Why have so many huge diamonds  been found recently?
 The auction house had called its  discovery "the find of a lifetime" and earlier  said that "every aspect of this auction is  unprecedented".
 The Lesedi la Rona, which means "our  light" in the Tswana language spoken in  Botswana, was discovered by Lucara  Diamond Corp's Karowe mine.
 After it failed to sell, the Canada-based  company - which has retained possession  of the diamond - saw its stock fall more    than 14% on the Toronto Stock  Exchange. According to a study by the  Gemological Institute of America, the  rough diamond's colour and transparency  "exemplify" type IIA diamonds.

Stones in this group are said to be "the most chemically pure and often show extraordinary optical transparency".

What are IIA diamonds?

  • IIA is the most chemically-pure type of diamond
  • Less than 2% of all gem diamonds are classed as IIA
  • They were first identified as originating from the famed Golconda region of India
  • Type IIA diamonds are now recovered in all major diamond producing regions
  • Famous examples of Type IIA diamonds are the Cullinan I and the Koh-i-Noor, both part of the British Crown Jewels 

In terms of its size the rough is exceeded only by the Cullinan Diamond, mined in South Africa in 1905 and presented to King Edward VII.

That 3,106-carat diamond was cut into nine stones, many of which are in the British Crown Jewels.

Credits: BBC News, Sotheby's.