Lucapa Diamond Co. Ltd.'s JORC-compliant resource estimate at its Lulo diamond mine in Angola grew 90% to 80,400 carats.
The average value for Lulo diamonds increased 17% over the previous estimate to US$1,420 per carat, according to a March 21 release.
The estimate accounts for 19 months of mining depletion to Dec. 31, 2018, during which time the company recovered over 30,000 carats of diamonds sold for about US$62 million.
The updated resource is based on defining additional resources via an ongoing resource definition drilling and sampling program, which included an additional 4,200 auger holes.
Lucapa discovered a new alluvial source of large diamonds at the Lulo mine in November 2018 and said it will continue testing other flood plain areas.
The company owns the Lulo project in partnership with Endiama EP and Rosas & Petalas SA, which hold 32% and 28%, respectively.