ASX-listed Newfield Resources’ Tongo diamond project, in Sierra Leone, now has a Joint Ore Reserves Committee-compliant resource estimate of about 7.4-million carats, spread across four kimberlites.
About 1.9-million carats, or about 25% of the updated in-situ resource, is classed in the indicated category, which underlines a considerably higher confidence level in key geological and technical parameters, Newfield executive director Mike Lynn said in a statement issued on Monday.
He explained that the diamond grades and values, in particular for the Kundu and Lando kimberlites, pointed to some of the most “impressive kimberlites globally on a dollar a tonne rock value basis”.
The updated resource estimate is also predominantly limited to a depth of 230 m from the surface.
However, previous deeper drilling suggests there is the potential for the global resource to be significantly increased in the future with more evaluation work.
It is for this reason that the company has previously described the Tongo project as a “potential generational asset”, the company said.
The updated grade and value results will be incorporated into the mine optimisation work being undertaken as part of the current front-end engineering and design programme on the Tongo project.
This programme remains on track for completion in the current quarter.