The company recovered a 404.2 carat diamond during alluvial mining at Mining Block 8, above the high-priority L259 kimberlitic signature, at the Lulo concession in Angola.
The diamond has been confirmed as a top-tier Type IIa D-colour gem.
Lucapa said it was the biggest diamond ever uncovered by an Australian company, and was the 27th biggest recorded diamond in the world.
The previous largest diamond recovered at Lulo was 133.4 carats, found only weeks ago.
The diamond represents the fourth 100-plus carat diamond found at Lulo since mining began in August 2015, and the 114th large special diamond.
Lucapa’s average selling price for run-of-mine diamonds has been $A2360 per carat, but this stone is expected to go for much more.
Last year, Toronto-listed diamond producer Lucara Diamond Corp sold a 336.3 carat Type IIA diamond for $US8.18 million ($24,324/carat), while a 341.9 carat Type IIA diamond sold for $20.55 million ($60,114/carat).
Lucapa CEO Stephen Weatherell said the company (40%) and its partners Endiama (32%) and Rosas & Petalas (28%) were proud of the find.
“We have always emphasised the very special nature of the Lulo diamond field and this recovery – together with the other 100 carat-plus diamonds recovered this year alone – is further evidence of that,” he said.
“And while we continue mining these exceptional alluvial gems from Mining Blocks 6 and 8 at Lulo, we are also continuing to advance our systematic program to find the kimberlite source of these diamonds.”
After emerging from a week-long suspension, Lucapa shares jumped by 30% to A41.5c after hitting an intraday high of 50c.
