Estimated to achieve in excess of $70 million*, the Lesedi la Rona (“Our Light” in the Tswana language spoken in Botswana) was uncovered by Lucara Diamond Corp. in November 2015, at their Karowe mine in Botswana. Around the size of a tennis ball (measuring approximately 66.4 x 55 x 42 mm), this colossal rough diamond of exceptional transparency and quality is around 2.5 to over 3 billion years old.

Diamonds have been mined continuously for centuries in multiple locations around the world and yet nothing of the size and quality of Lesedi La Rona has been found in over 100 years. In terms of its size, the rough is exceeded only by the legendary Cullinan Diamond, mined in South Africa in 1905. The 3016.75-carat Cullinan Diamond produced nine major diamonds that are part of the historic Crown Jewels of the United Kingdom, including the Great Star of Africa – currently the largest top- quality polished diamond in existence, weighing 530.20 carats.

According to a study by the Gemological Institute of America, the Lesedi La Rona’s “top colour and transparency exemplify the “limpid” appearance commonly associated with type IIa diamonds” – a rare and coveted subgroup which comprises less than 2% of all gem diamonds. Stones in this group are “the most chemically pure and often show extraordinary optical transparency".

Independent reports on the potential yield of the rough have also stated that the Lesedi la Rona may have the potential to yield the largest top-quality diamond that has ever been cut and polished**. These reports have also stated that there is a high probability that the resulting polished diamonds will be “D” colour – the highest colour classification for white diamonds.

“TheLesedila Ronais simply outstandingand its discovery is the find of a lifetime. It is a huge honour forSotheby’stohave been entrusted with its sale. Every aspect of this auction is unprecedented. Not only is the rough superlative in size and quality, but no rough even remotely of this scale has ever been offered before at public auction”.

William Lamb, President and Chief Executive Officer of Lucara Diamond Corp., said: “We are very excited to be partnering with Sotheby’s on this landmark auction. Lucara has made innovation the cornerstone of its development strategy and this has led to the historic recovery of the Lesedi La Rona diamond. The forthcoming sale presents a unique opportunity to present this extraordinary diamond to a worldwide audience.”

The Lesedi la Rona will be on view at Sotheby’s New York on 7 May, and at Sotheby’s London from 18 until 28 June, ahead of its auction in the evening of 29 June.

About Lucara Diamond Corp.Lucara Diamond Corp. is a Canadian diamond mining company with a producing mine and exploration licenses in Botswana. Its key asset is the Karowe Mine, a newly constructed state-of-the- art mine in the Letlhakane region which was fully commissioned in 2012. Karowe has consistently delivered large, Type IIA stones. Lucara is a member of the Lundin Group of Companies and is listed on the TSX Exchange, NASDAQ OMX First North Exchange, and the Botswana Stock Exchange under trading symbol “LUC”.

The company is fully committed to the responsible development of its assets. Its mission is to build a leading African-focused diamond production and development company. In 2015, the company was elected by the Prospectors and Developers Association of Canada (PDAC) to receive its 2016 Environmental and Social Responsibility Award. This award honours an individual or organization demonstrating outstanding initiative, leadership and accomplishment in protecting and preserving the natural environment and/or in establishing good community relations during an exploration program or operation of a mine.

About The Cullinan DiamondFound in Pretoria, South Africa in January 1905, the Cullinan Diamond was a large gem-quality rough diamond weighing 3,106.75 carats. The Cullinan was formally presented to King Edward VII in November 1907 and was subsequently cut. The rough yielded nine major high-quality polished diamonds, all of which reside in the Crown Jewels of the United Kingdom.

The world’s largest facetted white diamond and the first stone to be cut from the Cullinan rough was the pear-shaped Great Star of Africa, weighing 530.20 carats, which now sits atop the Sovereign’s Sceptre with Cross. This diamond remains the largest D-colour diamond in existence. The second polished diamond, known as Cullinan II or Second Star of Africa, is a rectangular cushion-cut diamond weighing 317.40 carats, which is fitted to the Imperial State Crown.

** Independent reports on the potential yield of the rough were commissioned by Sotheby’s from Gem Certification and Assurance Lab (GCAL) and Diamex Inc./Crodiam Consulting DMCC.