The Karowe mine has produced a 998-carat diamond, the latest in a string of large rough stones from the lucrative deposit in Botswana.

Lucara Diamond Corp., which owns Karowe, will work with manufacturing partner HB Antwerp to assess how to maximize value from the rough, the miner said Wednesday. The unbroken, high-white, clivage stone — meaning it needs to be split before further processing — came from the EM/PK(S) unit of the site’s south lobe, which has yielded some of the world’s biggest and most famous diamonds.

The Belgian manufacturer later agreed to purchase all of Lucara’s rough above 10.8 carats for the remainder of the year. Last week, Lucara announced the sale of a 549-carat diamond from the same high-value patch of Karowe, with HB and Louis Vuitton again partnering on the stone.

The arrangement with HB prevented a heavier decline in Lucara’s sales in the third quarter, the first period in which income from the partnership started appearing in the miner’s top line.

Group revenue fell 9% year on year to $41.3 million in the three months ending September 30, reflecting Lucara’s decision not to hold its usual tenders of stones above 10.8 carats, the company reported Wednesday. Instead, it sold 5,633 carats through the HB partnership, with sales taking place approximately twice a month, while the miner’s online selling platform, Clara, boosted sales of smaller goods.