An updated Mineral Resource Estimate was completed by Mineral Services Canada Inc. and published by Lucara on June 26th, 2018. The estimate is based on historical evaluation data combined with new sampling results (microdiamond, bulk density and petrography) from recent deep core drilling and from historical drill cores. New delineation drill coverage and review of historical drill cores supported an update of the internal geological model. Production data (including a controlled production run from the EM/PK(S) unit) and recent sales / valuation results have been incorporated into the grade and value estimates, which have been made based on an updated model of process plant recovery efficiency.
The updated Mineral Resource (Table 1a), valid at the cut-off date of 26 December 2017, includes a recoverable Indicated Mineral Resource at a 1.25 mm bottom cut off size of 7.9 million carats hosted in 57.85 million tonnes at an average grade of 13.7 cpht with an average modeled diamond value of US$ 673 per carat. The new base of the Indicated Mineral Resource is 400 masl (600 metres below surface). The updated Mineral Resource also includes a recoverable Inferred Mineral Resource of approximately 1.17 million carats hosted in 5.84 million tonnes at an average grade of 20 cpht with an average modeled diamond value of US$716 per carat between 400 masl to 256 masl (base of current geological model). The updated recoverable Indicated Mineral Resource for the South Lobe is presented in Table 1b, valid at a cut off date of 26 December 2017.
Table 1a: Statement of Remaining Mineral Resources in the AK06 kimberlite
The reported resources are those remaining (including stockpile material) as of 26 December 2017.
Table 1b: Statement of Remaining Indicated Mineral Resources in the South Lobe: AK06 kimberlite
1. m3 = million cubic metres, 2. tpm3 = tonnes per cubic metre, 3. Mt = million tonnes, 4. Mct = million carats, 5.cpht = recoverable (+1.25 mm) carats per hundred tonne, 6. $/ct = recoverable (+1.25 mm) United States dollars per carat. Tonnage, grade and value estimates are based on updated Mineral Resource Estimate prepared by MSC under the supervision of Dr. Tom Nowicki of Mineral Services Canada Inc. a “Qualified Person” within the meaning of NI 43-101 and independent of Lucara. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. The AK06 mining licence (ML2008/6L) expires in May 2023. The mining licence will have to be renewed for the underground development at AK06 to progress.