Reserves and Resources

The 2025 Mineral Resources for the Karowe Diamond Mine (KDM), as summarized below, have been classified as either Indicated or Inferred Mineral Resources, according to the CIM Definition Standards for Mineral Resources and Mineral Reserves (CIM, 2014). Mineral Resources reported are inclusive of those portions of the Mineral Resource that have been converted to Mineral Reserves and have an effective date of September 30, 2025.

For more information, see 2025 Karowe Mine Underground Feasibility Study Technical Report

KDM 2025 Mineral Resource Statement (effective date of September 30, 2025)

Notes:

1. Prepared by Hermanus Gr?tter, P.Geo, Ph.D. of SRK Consulting (Canada) Inc.;
2. CIM definitions were followed for Mineral Resources;
3. Effective date of September 30, 2025;
4. All numbers have been rounded to reflect accuracy of the estimate;
5. Mineral Resources are stated above a +1.25 mm bottom cut-off;
6. Average diamond value estimates are based on diamond sales data provided by Lucara Diamond Corp.;
7. Mineral Resources are in situ and inclusive of in situ Mineral Reserves;
8. Mineral Resources are exclusive of all mine stockpile material;
9. Mineral Resources have been estimated with no allowance for mining dilution and mining recovery;
10. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability; and
11. Inferred Mineral Resources are estimated on the basis of limited geological evidence and sampling, sufficient to imply but not verify geological grade and continuity. They have a lower level of confidence than that applied to an Indicated Mineral Resource and cannot be directly converted into a Mineral Reserve.

Source: SRK (2025)

For more information, see 2025 Karowe Mine Underground Feasibility Study Technical Report

Mineral Reserve Estimate

A consolidated open pit and underground mine plan was developed to extract the economic portions of Karowe Diamond Mine Indicated Mineral Resources plus stockpiled ore. The South Lobe is planned to be mined through a combination of open pit and underground mining methods. Centre and North Lobe will not be further mined. Stockpiled ore consists of a mix of all three kimberlite lobes (South, Centre, North). All Mineral Reserves are classified as Probable.

The open pit design and schedule was prepared by Lucara and reviewed by the Qualified Person (QP) and the underground design and schedule was prepared by QP. Stockpile quantities were prepared by Lucara and reviewed by the QP and are included in the Mineral Reserve Estimate. A consolidated summary of the Mineral Reserve Estimate, by mining method and lobe, is presented below.

The QP did not identify any extraordinary risk, including legal, political, or environmental that would materially affect potential Mineral Reserves development. The effective date of this Mineral Reserve Estimate is September 30, 2025.

Karowe Mine Mineral Reserve Estimate (September 30, 2025)

Notes:

1. Prepared by QP, Brandon Chambers, P.Eng. JDS Energy & Mining Inc.;
2. CIM definitions were followed for Mineral Reserves;
3. Process recovery of the diamonds was assumed to be 100% as the recoveries were included in the mineral resource block model assumptions;
4. The bottom elevation of the Probable Reserve is 250 masl;
5. Mineral Reserves are quoted above a +1.25 mm bottom cut-off diamond size and have been factored to account for diamond losses within the smaller sieve classes expected within the current configuration of the Karowe Mine Process Plant;
6. Average diamond price estimates are based on diamond sales data provided by Lucara Diamond Corp; prices were updated in 2025 for actual rough diamond sales over the period 2021 to end 2024, with partial sales data in 2025. The value of legacy diamonds (>US$5 million) has been incorporated in the financial model and are in addition to the diamond price estimate;
7. Tonnages are rounded to the nearest 100,000 tonnes, diamond grades are rounded to one decimal place to properly reflect the Reserve estimate accuracy. Rounding may cause minor discrepancies in the Mineral Reserve Estimate;
8. Tonnage and grade measurements are in metric units; contained diamonds are reported as thousands of carats;
9. Open Pit Mineral Reserves are estimated at a cut-off value of US$35/t based on an OP mining cost of US$13/t, a processing cost of US$12/t and a G&A cost of US$10/t;
10. Underground Mineral Reserves are estimated at a cut-off value of US$37/t based on an UG mining cost of US$15/t, a processing cost of US$12/t and a G&A cost of US$10/t;
11. OP dilution was assumed to be 0% as mining activities are primarily within the kimberlite. OP Mining Recovery of 95% has been assumed to account for potential challenges in achieving final bench elevations;
12. UG dilution assumptions were revised in 2025 as a result of geomechanical cave simulations. A total UG dilution of 23%, or 5.3 Mt has been included in the UG reserve estimate. Internal inferred domains are included as zero-grade waste. Cave drawdown simulations indicate that mine recovery will be 80% as of December 2037;
13. Stockpile Mineral Reserves are estimated at a cut-off value of US$19.50/t based on a rehandle cost of US$2.50/t, a processing cost of US$12/t and a G&A cost of US$5/t, when processed at the end of mine life;
14. Stockpile Reserves are not included in the Karowe Mineral Resource Estimate, which covered only in situ mineralized material;
15. Stockpile Reserves are based on surveyed volumes and block model grades; and
16. Stockpile LOM diamond price is determined from the weighted average of the North, Centre, South - M/PK(s), and South - EM/PK(s) lobe ratios. North lobe diamond price is estimated at US$155/ct; Centre lobe diamond price is estimated at US$210/ct.

For more information, see 2025 Karowe Mine Underground Feasibility Study Technical Report