Lesedi La Rona
The Lesedi La Rona in 2015
Weight1,111 carats (222.2 g; 7.14 ozt)
Dimensions65 mm × 56 mm × 40 mm (2.6 in × 2.2 in × 1.6 in)
ColourColourless/white, type IIa
CutRaw
Country of originBotswana
Mine of originKarowe Mine
Discovered16 November 2015
Original ownerLucara Diamond
OwnerGraff

Lesedi La Rona, formerly known in media as Karowe AK6 or as Quad 1[1] by the personnel at the mine, is the fourth-largest diamond ever found, and the third-largest of gem quality. It was found in the Karowe mine, (formerly called AK6) in Botswana on 16 November 2015.

British jeweller Graff bought the rough diamond for $53 million in 2017. By April 2019, Graff had cut it into one large emerald cut diamond, the Graff Lesedi La Rona, weighing 302.37 carats (60.47 g; 2.13 oz) and 66 smaller stones.[2]

Description

The Lesedi La Rona is a colourless/white,[3] type IIa diamond.[4] It weighs 1,111 carats (222.2 g; 7.84 oz) and measures 65 mm × 56 mm × 40 mm (2.6 in × 2.2 in × 1.6 in). In comparison, the Cullinan, discovered in 1905 in South Africa, weighed 3,106.75 carats (621.350 g).[5][6] The Lesedi La Rona was mined using Large Diamond Recovery ("LDR") XRT machines,[4] and is the largest diamond recovered using machines for automated diamond sorting.[3][7] It is estimated to be over 2.5 billion years old.[8]

It was found on 16 November 2015,[9] in the South Lobe of the Karowe mine about 200 m (660 ft) below the surface, and the find was announced on 18 November.[4][10] A day after the discovery, two more diamonds weighing 813 and 374 carats (162.6 and 74.8 g) were found in the mine.[11][12] Since the AK6 pipe was opened 18 months earlier, it has yielded over 1,000,000 carats (200 kg) of diamonds.[13]

The stone was too big for the company's scanners.[9]

Name

The diamond was first given a generic name after the mine (Karowe) and the pipe (AK6) where it was found.[13] On 18 January 2016, Chief Executive Officer William Lamb of Lucara Diamond announced a competition, open to all Botswana citizens, to name the stone. In addition to naming the diamond the winner would receive P25,000 (about $2,170).[14]

On 9 February 2016, Lucara Diamond announced that the stone had been named Lesedi La Rona which means "Our Light" in the Tswana language. The winner of the competition who named the diamond was Thembani Moitlhobogi from Mmadikola.[15][16][17] He stated that his reason for the name was that "the diamond is a pride, light and hope of Botswana".[17] During the competition Lucara Diamond Corporation received 11,000 emails and 1,000 SMSs with name suggestions.[18]

History

Diamond mines and kimberlite fields in Botswana

The diamond was found in the south lobe of Canadian company Lucara Diamond's Karowe Mine about 500 km (310 mi) north of Gaborone in Botswana.[4][12] The mine is located in the Letlhakane region, where three other diamond-producing kimberlite fields have mines named Orapa, Letlhakane and Damtshaa, with the Debswana Diamond Company Ltd.[13] The first diamond from the mine was retrieved in 2012. Botswana, South Africa and Namibia are the world's three top producers of mined diamonds.[3]

In the months after its discovery the diamond was exhibited in a world tour in Singapore, Hong Kong, New York, and Antwerp, a major centre of the world diamond trade.[19]

Value, first auction and sale

The exact value of the stone cannot be determined until it is decided how it will be cut and more details about its colour are known. Former diamond-mining geologist Phil Swinfen estimates, based on other similar sales, that the stone could be sold for $40–60 million.[3] The process of selling and cutting the diamond "will likely take years to complete".[20] In May 2016, Sotheby's in London announced that the Lesedi La Rona diamond would be offered in a stand-alone auction on 29 June 2016.[21] It was expected to sell for around $70 million. After closer examination,[22] the diamond was presented at the auction as weighing 1,109 carats. The highest bid for the diamond was $61 million. However, this bid fell short of the undisclosed reserve price and the stone was not sold.[23] The bidding opened at $50 million and the auction lasted for less than 15 minutes.[24]

In June 2016, Lesedi La Rona was insured for $120 million.[25] It was sold in September 2017 for $53 million to British jeweller Graff Diamonds.[26]

Cutting

On 10 April 2019, jeweller Graff presented the stones cut from Lesedi La Rona. It was divided into one large and 66 smaller diamonds. Due to the size of the rough stone, Graff had to custom-build a new scanner with new imaging software to analyze it for the cutting. The main stone, named the Graff Lesedi La Rona, is the world's largest emerald-cut diamond. It is a D-color (totally colorless), high-clarity stone weighing 302.37 carats (60.474 g; 2.1332 oz). According to Graff, the stone is the "largest highest clarity, highest color diamond ever graded by the Gemological Institute of America (GIA)". The other 66 stones cut from the original Lesedi La Rona range in size from 26 carats (5.2 g; 0.18 oz) to below one carat (0.20 g; 0.0071 oz). Each stone is inscribed with “Graff, Lesedi La Rona” and a specific GIA number.[2][27]

Technology

The diamond was recovered by a TOMRA large diamond recovery (LDR) machine utilizing X-ray transmission sensors.[7] In May 2015, the operation at the Karowe Diamond Mine replaced their Dense Media Separation (DMS) technology with six TOMRA XRT sorters for sorting material in the -60+8 mm size range. The X-ray transmission (XRT) sorting technology was selected following a suite of tests. Each sorter can sort up to 150 metric tons (330,000 lb) of material per hour, after that the concentrate goes directly to hand sorting.[28] Karowe Diamond Mine is the first mine using this automated diamond sorter.[29]

See also

References

  1. ↑ Because of its initial pre-cleaning weight of 1,111 carats (222.2 g; 7.84 oz).
  2. 1 2 DeMarco, Anthony (10 April 2019). "Graff Unveils World's Largest Square Emerald Cut Diamond At 302.37 Carats". Forbes. Retrieved 13 April 2019.
  3. 1 2 3 4 MacDonald, Alex (19 November 2015). "World's Second-Largest Diamond Discovered in Botswana". www.wsj.com. The Wall Street Journal. Retrieved 20 November 2015.
  4. 1 2 3 4 "Lucara makes diamond history recovers 1,111 carat diamond" (PDF). www.lucaradiamond.com. Lucara Diamond. Archived from the original (PDF) on 20 November 2015. Retrieved 20 November 2015.
  5. ↑ "Second largest gem quality diamond ever found recovered in Botswana". www.telegraph.co.uk. The Telegraph. Retrieved 19 November 2015.
  6. ↑ MacDonald, Alex (19 November 2015). "World's Second-Largest Diamond Discovered in Botswana". The Wall Street Journal. Retrieved 19 November 2015.
  7. 1 2 "TOMRA sorting mining congratulates Lucara Diamond Corp. upon the recent recovery of a magnificent 1,111 ct IIA diamond using TOMRA x-ray transmission (XRT) technology at their Karowe mine in Botswana". www.tomra.com. TOMRA. 24 November 2015.
  8. ↑ "Lesedi la Rona diamond set to be sold at auction for £52m". www.bbc.com. BBC News. 29 June 2016. Retrieved 29 June 2016.
  9. 1 2 "Biggest diamond in 100 years adds $150 million to miner". www.cnn.com. CNN. 19 November 2015. Retrieved 20 November 2015.
  10. ↑ "Lesedi La Rona". www.sothebys.com. Sotheby's. Retrieved 29 June 2016.
  11. ↑ "Lucara Recovers Two More Large Diamonds Including an 813 Carat Stone from the Karowe Mine in Botswana". www.lucaradiamond.com. Archived from the original on 2015-11-19. Retrieved 2016-06-30.
  12. 1 2 "World's second-largest diamond 'found in Botswana'". www.bbc.com. BBC. Retrieved 20 November 2015.
  13. 1 2 3 Cornish, Laura (27 May 2015). "Lucara Diamonds looks for buyers for 342 carat in July exceptional stone tender". www.miningreview.com. Spintelligent (Pty) Ltd. Retrieved 20 November 2015.
  14. ↑ Ngwako, Portia (18 January 2016). "Batswana To Name Biggest Diamond". www.thevoicebw.com. The Voice Pty Ltd. Archived from the original on 1 February 2016. Retrieved 29 January 2016.
  15. ↑ "Lucara Names 1,111 Carat Diamond Lesedi La Rona". www.marketwired.com. Marketwired L.P. 9 February 2016. Retrieved 10 February 2016.
  16. ↑ "Lucara Names 1,111 Carat Diamond Lesedi La Rona". www.lucaradiamond.com. Lucara Diamond. 2016-06-30. Archived from the original on 15 May 2016. Retrieved 10 February 2016.
  17. 1 2 Ngwako, Portia (9 February 2016). "Largest Diamond Named". www.thevoicebw.com. The Voice Newspaper Botswana. Archived from the original on 11 February 2016. Retrieved 11 February 2016.
  18. ↑ le Cordeur, Matthew (9 February 2016). "Largest diamond found in 100 years named". fin24.com. News24. Retrieved 10 February 2016.
  19. ↑ Lars Andersen (27 May 2016). "Largest uncut diamond in the world at Antwerp: exclusive presentation". The Brussels Times. Retrieved 29 June 2016.
  20. ↑ Nace, Trevor (20 November 2015). "Diamond – The World's Second Largest – Was Found In Botswana". Forbes. Retrieved 23 November 2015.
  21. ↑ Becker, Vivienne (5 May 2016). "Lesedi La Rona: The Diamond of a Lifetime". www.sothebys.com. Sotheby's. Retrieved 7 May 2016.
  22. ↑ Metha, Diana (4 May 2016). "Tennis-ball sized diamond found by Canadian firm could fetch $90M". www.ctvnews.ca. CTV News. Retrieved 7 May 2016.
  23. ↑ "Tennis-ball sized Lesedi La Rona diamond fails to sell at London auction". www.cbc.ca. Canadian Broadcasting Corporation. 29 June 2016. Retrieved 29 June 2016.
  24. ↑ DeMarco, Anthony (29 June 2016). "World's Largest Rough Diamond Fails to Sell At Auction". Forbes. Retrieved 29 June 2016.
  25. ↑ "Lesedi La Rona insured for P1.3bn". www.mmegi.bw. Mmegi. 29 June 2016. Retrieved 29 June 2016.
  26. ↑ "World's biggest uncut diamond sells for $53m". 26 September 2017. Retrieved 26 September 2017.
  27. ↑ "Introducing The Graff Lesedi La Rona". Graff. Retrieved 13 April 2019.
  28. ↑ "TOMRA equipment key to record Lucara diamond recovery". International Mining. 27 November 2015. Retrieved 2 March 2016.
  29. ↑ Creamer, Martin (9 June 2015). "Pioneering Botswana diamond circuit set for design run this month". www.miningweekly.com. Mining Weekly. Retrieved 7 May 2016.
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