Koidu Limited

Processing of the first kimberlite from K1 began in January 2004 and continued until mid-2004, when sampling switched to K2 to allow for waste stripping and establishment of the headgear, hoist, winder and associated infrastructure at the collar of the planned vertical pit at K1.

From August 2005 to December 2007, the mine focused exclusively on extracting ore from the K1 pit, establishing the largest and deepest excavation of its kind world-wide while attempting to minimize the impact on the nearby Koidu community.

Given the limited lifespan of the vertical pit (maximum 80 m from collar), the company embarked on an exploration core drilling programme to delineate sufficient resources for at least the remaining life of the mining lease period.

From 2003 to 2008, four phases of core drilling were completed; once the magnitude of potentially mineable resources began to emerge, desktop studies considering the possible scenarios for the future expansion of the mining operation were undertaken.

After significant additional bulk sampling exercises in 2009 and 2010 (both from large-scale surface excavations and large-diameter drilling programmes on K2, Dyke Zones A and B, as well as the four blows intended to form part of the life-of-mine plan), the resource statement was signed off by diamond specialists Mineral Services Canada in their capacity as independent competent persons.