The 1,758 carat uncut diamond weighs close to 352 grams and measures 83 millimetres by 62 mm by 46 mm
The mine has now produced two diamonds greater than 1,000 carats in four years.
Since introducing its XRT diamond recovery technology, Lucara has found 12 diamonds, which have been over 300 carats, including a 472 carat and a 327 carat diamond in April last year.
Lucara shares slipped 1.79% to $1.65 each.
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