ASX-listed Newfield Resources is, along with its technical partners PPM, SRK Consulting and Datamine, nearing completion of the front-end engineering design study for its Tongo diamond project, in Sierra Leone.
The outcome of the study is expected to be released in the first quarter of this year.
Moreover, final mine optimisation is ongoing and is set to be completed shortly.
Newfield has been granted 25-year renewable mining licences for the 9.98 km2 area held by its subsidiary company Sierra Diamonds.
Box preparation for the portal entrance and decline development have also started.
Excavations and shaping of the boxcut for a single access portal is aimed at maximising efficiency in the planned mine development schedule, Newfield executive director Karl Smithson indicated in a statement on Tuesday.
The company has also exported 1 626 ct of diamonds for valuation, with up to 48% collection goods, which are diamonds with top colours in the D to G range.