Reserves & Resources

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.

Please see the 2018 Technical Report for the Karowe Mine: Updated Mineral Resource Estimate for further information related to Reserves and Resources

Karowe Resource (AK06 kimberlite) Update

During Q2 2018, an updated mineral resource was announced for the AK06 kimberlite. The updated Mineral Resource Estimate was completed by Mineral Services Canada Inc. 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 Eastern magmatic/pyroclastic kimberlite ((“EM/PK(S)”) unit) and recent sales and 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 is reported based on the Canadian Institute of Mining Definition Standards for Mineral Resources and Reserves as incorporated by National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI-43-101”).

In 2018, the Company embarked on a technical program to support a Feasibility Level study for a potential underground operation at the Karowe Diamond Mine. This program included the completion of an updated mineral resource, geotechnical drilling of the country rock and AK06 kimberlite, hydrogeological drilling and modelling, and mining trade off studies to address risks and issues identified during the PEA.  A total of $21.0 million was spent in 2018 in support of this work, which resulted in significant de-risking of the key technical components associated with the potential underground development. 

During H1 2019, $8.4 million was spent to complete the geotechnical drilling program, geotechnical and geological logging, downhole geophysical survey, hyperspectral analysis of core, geotechnical modeling, hydrogeological drilling and studies, and mine planning activities in support of the ongoing feasibility study. Field programs were completed in late April 2019 and the results are being incorporated into the feasibility study with a planned completion date in Q4 2019.