Lucara Diamond Corp. said it has found a 998-carat high white diamond, putting it among the five largest stones ever discovered. Still, Lucara said the diamond was clivage, meaning it will need to be split before further processing into polished gems. Lucara’s Karowe mine is becoming famous for giant stones. In 2015, the company found the 1,109-carat Lesedi La Rona, which sold for $53 million, while the mine has also yielded a 813-carat Constellation stone that fetched a record $63 million. Lucara also discovered a 1,758-carat diamond last year, though it was a near gem of variable quality, meaning it won’t yield incredibly valuable polished diamonds on a par with earlier finds.