(IDEX Online) - Estimated diamond reserves at the Lulo mine, in Angola, have been revised up by 25 per cent.Independent consultants have assessed in-situ resources as 100,700 carats, more than five times the 2019 output of around 19,000 carats.They also say the average dollar per carat value is 14 per cent higher than previously thought, up from $1,420 to $1,620.The Australia-based Lucapa Diamond Company is in its fifth year of exploring hard-rock kimberlite sources in the Canguige tributary catchment area, which has yielded some top D-color stones and some rare Type IIa gems."We are confident we can continue to build on the alluvial resource given the vast areas along the Cacuilo River valley which remain unexplored, coupled with the fact we are now delineating alluvial diamond zones in both the terraces and the flood plain (leziria) areas," said Lucapa managing director Stephen Wetherall."With that in mind, and with the recent arrival on site of two additional auger rigs, we will see a significant step up in our resource-definition drilling and pitting programs in 2020."The Lulo Diamond Resource was independently estimated and reconciled on a depletion and addition basis as at 31 December 2019 by Z Star, of South Africa.