(IDEX Online) - Lucara has announced its first notable recovery of 2024, a 166-ct Type IIa gem.It is the 328th +100-ct diamond since the Karowe mine, in Botswana, began commercial production in 2012.The stone was recovered in the Coarse XRT unit from direct milling of ore sourced from the M/PK(S) unit of the South Lobe.Karowe has also yielded four +1,000-ct diamonds in that time, most recently a 1,080.1-ct stone recovered last August."This latest recovery further supports the economic rationale for investing in the underground expansion project that will extend mine life to at least 2040," said CEO William Lamb.Vancouver-based Lucara recently announced the latest in a series of extensions to the finance facility funding its underground expansion at the mine. The $683m project is above budget and behind schedule.Among the miner's biggest recoveries are a 1,109-carat stone - the world's largest gem-quality rough diamond found in more than a century - recovered In November 2015.It was bought in November 2017 by Graff Diamonds for $53m and cut into the 302.37 carat Graff Lesedi La Rona and 66 satellite stones.In April 2019, Lucara recovered the 1,758-carat Sewelo diamond - the world's third biggest rough diamond ever. It was bought in January 2020 by Louis Vuitton for an undisclosed sum.