Announcement • Mar 28
Strategic Minerals plc Announces Updated Mineral Resource Estimate for Redmoor Project
Strategic Minerals plc announced an updated Mineral Resource Estimate ("MRE") for the Redmoor tungsten-tin-copper-silver Project ("Redmoor") in southeast Cornwall, UK held by its wholly owned subsidiary, Cornwall Resources Limited ("CRL"). 2026 MRE Highlights · 100% Inferred MRE reported in accordance with JORC (2012) of 17.4 Mt @ 0.65%Tungsten Trioxide Equivalent1("WO3.Eq"): · Represents a49% increase in tonnage compared to the previous 2019 MRE. · 2.4x increase in potential mine life from 12 to 29 years, at 2020 Scoping Study production rate. · The 2026 MRE comprises 17.4 Mt at 0.65% WO3 Eq, including 0.49% WO3, 0.17% Sn and 0.44% Cu: containing 85.8 kt WO3, 29.0 kt Sn and 76.3 kt Cu. Significant increase in contained metal within the 2026 MRE, including: · Tungsten trioxide(WO3): 31% increase in contained WO3 · Tin(Sn): 55% increase in contained Sn · Copper(Cu): 30% increase in contained Cu · Silver(Ag): with an average grade of 5.8 g/t, and 3,231 koz contained silver. Silver included as a Cu concentrate credit at 270g/t. · Mineral Resources are reported within underground Mineable Shape Optimiser (MSO) stope shapes and above a net smelter return ("NSR") cut-off of USD 110/t, demonstrating reasonable prospects for eventual economic extraction ("RPEEE"). · An Exploration Target of 1.8 - 3.4 Mt JORC (2012) grading 0.4 - 0.6% WO3, 0.08 - 0.12% Sn and 0.2 - 0.3% Cuhas also been identified outside of the current MRE · Confirms Redmoor at 0.49% WO3(0.65% WO3.Eq) is Europe's highest-grade, undeveloped, tungsten projectcompared to other CRIRSCO-compliant projects2. Updated geological and mineralisation models incorporating revised interpretations of the Redmoor deposit. · Inclusion of historical South West Minerals ("SWM") drilling data from the 1980s, including logging and sampling information, to better inform geological modelling and the MRE. · Inclusion of additional CRL sampling from 2017-2018, following targeted re-logging and sampling of intervals that were previously unsampled. · Inclusion of nine CRL drillholes completed in 2025 (4,998 m), designed to verify historical SWM drilling, infill previously untested areas, and support evaluation of drill spacing required for higher-confidence resource classification. · The 2025 drilling has confirmed continuity of mineralisation in areas that were previously sparsely drilled or untested. · Expanded mineralisation modelling, including previously unmodelled HGDs and lodes, enabled by the incorporation of historic drilling and new geological interpretation. · Updated domain modelling including separate tungsten and tin HGDs, a broad copper zone within the SVS, and a low-grade SVS envelope. · Updated metal price assumptions and metallurgical recoveries, incorporating results from recent 2025-2026 metallurgical testwork including full flowsheet testing. · The Mineral Resource is now reported within underground MSO stope shapes and above an NSR cut-off, reflecting RPEEE, which was not applied in the 2019 estimate. • The updated Mineral Resource excludes mineralisation between surface and -20 mRL (200 m crown pillar) to account for potential planning constraints related to blasting vibrations beneath surface dwellings, as highlighted in the 2020 Scoping Study. 2026 MRE ADDITIONAL INFORMATION Grade Tonnage Assessment: The grade-tonnage has been reported inside of the RPEEE MSO stope shapes. The increase in metal prices moved more lower-grade tonnes above the NSR cutoff, with the effect of a marginal decrease in grade, but an increase in contained metal. Exploration Potential The Exploration Target at the Redmoor deposit refers to mineralised material that has been interpreted from geological modelling and limited drillhole information but lies outside the current Mineral Resource classification envelope. These areas are considered prospective for mineralisation; however, the available drilling density, geological confidence, and grade continuity are insufficient to support classification as an Inferred Mineral Resource in accordance with the JORC Code (2012). The Exploration Target tonnage and grade estimates have been derived using the existing geological model, but they are conceptual in nature and should not be interpreted as Mineral Resources. Further drilling, geological confirmation, and additional sampling are required before any portion of this material could be upgraded to an Inferred Mineral Resource. There is no certainty that further exploration will result in the delineation of a Mineral Resource. In accordance with the JORC Code (2012), an Exploration Target must be reported as a range of tonnage and grade. Between 1.8 Mt and 3.4 Mt has been classified as an Exploration Target, based on the criteria outlined above. Classification The Mineral Resource has been classified following the guidelines of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, 2012 (the JORC Code). The Mineral Resource has been classified as Inferred on the basis of confidence in geological and grade continuity, by taking into account the quality of the sampling and assay data, and confidence in estimation of WO3, tin and copper. The classification criteria were assigned on an individual domain basis and were based on the robustness of the grade estimate as determined from the drillhole spacing, geological confidence and grade continuity and reflects the confidence and uncertainty in the model. Inferred: All domains below the designated blast safety buffer, supported by drilling intersections at spacings of approximately 100-200 m along strike and 60-120 m down dip. Classification is further supported by appropriate quality assurance and quality control (QAQC) procedures and the overall quality and integrity of the assay dataset. Reasonable Prospect for Eventual Economic Extraction ("RPEEE") Assessment The Redmoor Mineral Resource has been assessed for RPEEE in accordance with the JORC Code. Underground RPEEE The underground 2026 MRE was reported within Datamine MSO optimised stope shapes to satisfy the requirement for RPEEE. The assumed mining method is sublevel open stoping and this was assumed as a mining method for the Redmoor 2020 Scoping Study.