Mandalay Resources Corporation updated Mineral Reserves and Resources for the Costerfield mine in Victoria, Australia and an Interim Mineral Reserve update for its Bjorkdal mine in Vasterbotten County, Sweden as at December 31, 2023. The ongoing exploration efforts have generated significant value over time, and the Company remains steadfast in its commitment to exploring both near the mine and regionally to unlock even further value at Costerfield with increased exploration spend for 2024. Costerfield Mineral Resource and Mineral Reserve Summary.

All samples were submitted to Onsite Laboratory Services in Bendigo, Victoria, Australia for sample preparation and assay. Site geological and metallurgical personnel have implemented a QA/QC process that includes the regular submission of site specific and externally sourced standard reference materials, duplicates and blanks with drill and face samples submitted for assay. Site specific standard reference materials were both produced and certified by Geostats Pty Ltd. or ORE Research and Exploration Pty Ltd. (OREAS).

This method is considered most applicable for the narrow veins of Costerfield. The Datamine? Studio RM platform supports 2D accumulation estimation and was used to complete the Mineral Resource Estimation.

Validated drilling and mine sampling data were imported into Datamine and composited to full intersection width. Gold accumulation, antimony accumulation (accumulation = vein true width x vein grade) and true vein width were estimated into a 2D block model for each lode using ordinary kriging interpolation. Mr. Gniel fulfils the requirements to be a "Qualified Person" for the purposes of NI 43-101, and is the Qualified Person under NI 43-101 for the Mineral Resource Estimate.

The Measured and Indicated categories of Mineral Resources were used to update the mine plan using predominantly a long-hole stoping mining method with cemented rock fill. An operational cut-off grade of 6.0 g/t AuEq was determined from Costerfield's 2023 production costs, and minimum stoping widths of 1.5 metres were used, with planned and unplanned dilution at zero grade for both Au and Sb. Owing to the longevity of the Bjorkdal Mine and consistency of Mineral Resources replacement, Mandalay chose not to complete and report a full 2023 year end Mineral Resources and Mineral Reserves estimate reported in First Quarter 2024.

Grade and tonnage scientific factoring has been applied in areas characterised by a high potential for discovery of new veins not predicted in the initial models but observed once mining faces intersect the veins. No new drilling, mapping, or sampling data acquired subsequent to that cut-off date has been included as yet. The remainder, approximately 34,000 gold ounces, is due to capping losses in developed areas of the underground mine, and losses due to removal of development and stopes containing a high proportion of Inferred gold ounces.

An updated Long-Term Block Model, that will include drilling up to the end of September 2024, is currently in the process of being developed in preparation for the filing of an updated Mineral Resource estimate and NI 43-101 Technical Report in March 2025. All Qualified Persons listed below have read and approved the contents of this news release as it pertains to the Mineral Resource and Mineral Reserve estimates.