Two diamond companies conducting exploratory surveys on neighbouring concessions of land in eastern Sierra Leone say they have discovered large deposits of diamonds, Mining.com reported.

Both Stellar Diamonds PLC and Koidu Holdings announced positive results from their bulk sampling operations in the Nimini Hills area of Kono district.

According to Stellar, there are kimberlite dykes running from the north-east area of its concession to the south-west. They expect that the kimberlite dykes present in the next concession over, a 50-square kilometer area operated by diamond company Oraco Resources, will be found to run in the same direction. Stellar's chief executive Karl Smithson called the find "of both high grade and high diamond quality".

BSG Resources-owned Koidu Holdings confirmed that the kimberlite dykes on their own adjacent territory run in the same direction. On account of their successful operations, the diamond company has decided to upgrade its processing plant. The facility, which currently processes 50 tonnes per hour, will be upgraded to be able to process 130 tonnes per hour.