Perseus Updates Mineral Resource and Reserve Estimates

perth, Aug. 21, 2025 (GLOBE NEWSWIRE) -- PERSEUS MINING UPDATES MINERAL RESOURCES AND

ORE RESERVE ESTIMATES

Executive Summary

Perth, Western Australia/August 21, 2025/Perseus Mining Limited (ASX/TSX: PRU) is pleased to update estimates of its Mineral Resources and Ore Reserves as of 30 June 2025. A summary of the release is included below. For the full release please refer to , or

The Perseus Group’s Measured and Indicated (M&I) Mineral Resources now total 7.8 Moz gold (Table 1) while Proved and Probable Ore Reserves total 5.0 Moz gold (Table 2). Not included in these estimates, is the Foreign/Historical Estimate for the Meyas Sand Gold Project (MSGP, formerly Block 14) including Indicated Mineral Resources¹ consisting of 3.3 Moz Au (Table 3) and a Probable Mineral Reserve¹ of 2.9 Moz gold (Table 4).

The sources of change underlying the 2.1 Moz gold increase in Perseus’s estimate of Ore Reserves against those reported at 30 June 2024 are presented in Error! Reference source not found.. As part of its annual planning cycle, the Company has reassessed the growth opportunities available within its portfolio with the approach of optimising the portfolio rather than focussing on fixed investment targets for each asset. In this way, the Company has sought to find the balance between investment in growth opportunities and the cash margin generated by the business.

Figure 1: Change in Perseus Group Ore Reserves by Project – June 2024 to June 2025

1. PERSEUS ESTIMATES

Table 1: Perseus Mining Mineral Resources^1,2,4,5

Table 2: Perseus Mining Ore Reserve^1,4,5

Notes for Table 1 and Table 2:

1        Refer to Notes to individual tables of Mineral Resources and Ore Reserves in respect of each project presented below.

2        Mineral Resources are inclusive of Ore Reserves.

3        Sissingué Mineral Resources and Ore Reserves include the Fimbiasso and Bagoé Projects in addition to the Sissingué Gold Mine.

4        The Company holds 90% of Edikan Gold Mine (EGM) and Yaouré Gold Mine (YGM), 86% of Sissingué Gold Mine (SGM) except Bagoé at 90%, and 80% of Nyanzaga Gold Project (NGP).

5        Excludes Foreign/Historical Estimates

Foreign/historical estimates

Table 3: Summary of Meyas Sand Gold Project Mineral Resource ^1,2,3,4,6

Notes for Table 3:

1. Based on September 2018 estimates of Galat Sufar South and Wadi Doum Mineral Resources by MPR Geological Consultants Pty Ltd.
2. 0.6 g/t cut-off grade applied to all material types.
3. Estimates are not depleted for artisanal mining, the impact of which is not considered material.
4. Galat Sufar South Mineral Resource estimates are truncated at 350 m depth, with around 90% of Indicated and Inferred resources occurring at depths of less than 240 and 300 m respectively. Wadi Doum estimates extend to around 255 m depth, with around 90% of Indicated and Inferred resources occurring at depths of less than 115 m and 190 m respectively. The depth limits imposed on the estimates are considered to largely confine the estimates to material with reasonable prospects of eventual economic extraction.
5. Indicated Mineral Resources are inclusive of Mineral Reserves.
6. Rounding of numbers to appropriate precisions may have resulted in apparent inconsistencies.

Table 4: Summary of Meyas Sand Gold Project Mineral Reserves^1,2,3,4,5

Notes for Table 4:

1. Based on Mineral Reserve Statement 7 November 2018.
2. CIM Definition Standards were followed for the classification of Mineral Reserves.
3. Mineral Reserves were optimised using a gold price of US$1,100/oz.
4. Mining Cut-off grades vary between 0.32 g/t and 0.90 g/t.
5. Rounding of numbers to appropriate precisions may have resulted in apparent inconsistencies.
   
   
   
   

Perseus’s Mineral Resource Estimates

The Perseus Group’s total M&I Mineral Resources reported as at 30 June 2025 are estimated to be 185.9 Mt grading 1.30 g/t gold, containing 7.8 Moz of gold, compared with the estimate of 30 June 2024 of 115.9 Mt grading at 1.31 g/t Au for 4.9 Moz of gold. The Mineral Resource Statement accounts for mining depletion of in-situ Mineral Resources and is reported inclusive of Ore Reserves. Inferred Resources are 39.9 Mt grading at 1.5 g/t Au for 1.9 Moz of gold, compared with the estimate of 30 June 2024 of 24.1 Mt grading at 1.6 g/t Au for 1.3 Moz of gold. Tonnes are reported as dry metric tonnes. All tabulated tonnes, grade and metal have been rounded to reflect appropriate precision in the estimate and may cause some discrepancies in totals.

The Foreign/Historical Estimate for the MSGP Mineral Resource in Northern Sudan, announced on 28 February 2022 (see news release titled “Perseus enters into agreement to acquire Orca Gold Inc.”) is stated in the ‘Foreign/Historical Estimate’ subsection of this report and is reported separately from the Group’s Mineral Resources detailed below.

The Group Mineral Resource estimates are reported in accordance with the 2012 Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code 2012). The classification categories of Measured, Indicated and Inferred under the JORC Code (2012) are equivalent to the CIM categories of the same names (CIM, 2014).

For the purpose of satisfying “reasonable prospects for eventual extraction” (JORC Code 2012), open pit Mineral Resources are reported above optimised open pit shells developed with actual and estimated operating costs and a long-term gold price assumption of US$2,100 per ounce, with the exception of Nyanzaga reported at US$2,000 per ounce. Underground Mineral Resources at CMA are constrained to below the CMA Stage 3 pit design and reported at a 1.5 g/t Au cut-off. Underground Mineral Resources at Edikan are constrained to a depth of 600 mRL at Esuajah South and are all exclusive of open pit Mineral Resources.

Technical Reports associated with these Mineral Resources, have been prepared in accordance with NI 43-101 for the following operations:

• Nyanzaga Gold Project, Tanzania, NI 43-101 Technical Report, dated 10 June 2025
• Yaouré Operations, Côte d’Ivoire, NI 43-101 Technical Report, dated 18 December 2023
• Sissingué Operations, Côte d’Ivoire, NI 43-101 Technical Report, dated 29 May 2015
• Edikan Operations, Ghana, NI 43-101 Technical Report, dated 6 April 2022

These reports can be found on Perseus’s website at and on the Canadian System for Electronic Document Analysis and Retrieval (SEDAR) website .

Perseus’s Ore Reserve Estimate

1. CRITERIA FOR ORE RESERVE CLASSIFICATION

All Ore Reserves are reported in accordance with the JORC Code (2012) and are reported by category, deposit and type, above variable cut-off grades. The classification categories of Proved and Probable under the JORC Code (2012) are equivalent to the CIM categories Proven and Probable respectively (CIM, 2010).

The Ore Reserve is classified as Proved and Probable corresponding to the Mineral Resource classifications of M&I and considering other factors where relevant. The deposits’ geological models are well constrained. The Ore Reserve classification is considered appropriate given the nature of the deposits, the moderate grade variability, drilling density, structural complexity, confidence in input parameters based on operational experience and mining history. It was therefore considered appropriate to use Measured Mineral Resources as a basis for Proved Ore Reserves and Indicated Mineral Resources as a basis for Probable Ore Reserves.

No Inferred Mineral Resources were included in Ore Reserve estimate with the exception of 2.8 koz of incidental Inferred which is included in the CMA underground development and is not considered material to the Ore Reserve.

Technical Disclosure:

All Mineral Reserves and Mineral Resources other than the Foreign/Historical Estimates were calculated as of 30 June 2025 and have been calculated and prepared in accordance with the standards set out in the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves dated December 2012 (the “JORC Code”) and in accordance with National Instrument 43-101 of the Canadian Securities Administrators (“NI 43-101”). The JORC Code is the accepted reporting standard for the Australian Stock Exchange Limited (“ASX”).

The definitions of Ore Reserves and Mineral Resources as set forth in the JORC Code (2012) have been reconciled to the definitions set forth in the CIM Definition Standards. If the Mineral Reserves and Mineral Resources were estimated in accordance with the definitions in the JORC Code, there would be no substantive difference in such Mineral Reserves and Mineral Resources.

Competent Person Statement:

The information in this report that relates to Mineral Resources is based on, and fairly represents, information and supporting documentation prepared by Daniel Saunders, a Competent Person who is a Fellow of The Australasian Institute of Mining and Metallurgy. Mr Saunders is a full-time employee of Perseus Mining Limited. Mr Saunders has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’” and to qualify as a “Qualified Person” under National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”). Mr Saunders consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

The information in this report that relates to Ore Reserves is based on information compiled by Mr Adrian Ralph, a Competent Person who is a Fellow of The Australasian Institute of Mining and Metallurgy. Mr Ralph is a full-time employee of Perseus Mining Limited. Mr Ralph has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activities which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves” and a Qualified Person as defined in NI 43-101. Mr Ralph consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.

The Company confirms that the material assumptions underpinning the estimates of Ore Reserves described in “Technical Report — Edikan Gold Mine, Ghana” dated 6 April 2022, “Technical Report — Yaouré Gold Project, Côte d’Ivoire” dated 18 December 2023, “Technical Report — Sissingué Gold Project, Côte d’Ivoire” dated 29 May 2015, and “Technical Report — Nyanzaga Gold Project, Tanzania” dated 10 June 2025 continue to apply.

Meyas Sand Gold (formerly Block 14) Project – Foreign/historical estimates

The information in this report that relates to the Mineral Resources and Probable Reserves of the Block 14 Project was first reported by the Company in a market announcement “Perseus Enters into Agreement to Acquire Orca Gold Inc.” released on 28 February 2022. The Company confirms it is not in possession of any new information or data relating to those estimates that materially impacts of the reliability of the estimate of the Company’s ability to verify the estimate as a Mineral Resource or Ore Reserve in accordance with Appendix 5A (JORC Code) and the information in that in that original market release continues to apply and have not materially changed. These estimates are prepared in accordance with Canadian National Instrument 43-101 standards and have not been reported in accordance with the JORC Code. A competent person has not done sufficient work to classify the resource in accordance with the JORC Code and it is uncertain that following evaluation and/or further exploration work that the estimate will be able to be reported as a Mineral Resource or Ore Reserve in accordance with the JORC Code. Mr Saunders and Mr Ralph have reviewed this press release and all technical information regarding Orca’s NI 43-101 Foreign/historical estimate and this information is approved by Adrian Ralph and Daniel Saunders, each a Qualified Person for the purposes of NI 43-101.

Caution Regarding Forward Looking Information:

This report contains forward-looking information which is based on the assumptions, estimates, analysis and opinions of management made in light of its experience and its perception of trends, current conditions and expected developments, as well as other factors that management of the Company believes to be relevant and reasonable in the circumstances at the date that such statements are made, but which may prove to be incorrect. Assumptions have been made by the Company regarding, among other things: the price of gold, continuing commercial production at the Yaouré Gold Mine, the Edikan Gold Mine and the Sissingué Gold Mine without any major disruption, development of a mine at Nyanzaga, the receipt of required governmental approvals, the accuracy of capital and operating cost estimates, the ability of the Company to operate in a safe, efficient and effective manner and the ability of the Company to obtain financing as and when required and on reasonable terms. Readers are cautioned that the foregoing list is not exhaustive of all factors and assumptions which may have been used by the Company. Although management believes that the assumptions made by the Company and the expectations represented by such information are reasonable, there can be no assurance that the forward-looking information will prove to be accurate. Forward-looking information involves known and unknown risks, uncertainties, and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any anticipated future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, the actual market price of gold, the actual results of current exploration, the actual results of future exploration, changes in project parameters as plans continue to be evaluated, as well as those factors disclosed in the Company's publicly filed documents. Readers should not place undue reliance on forward-looking information. Perseus does not undertake to update any forward-looking information, except in accordance with applicable securities laws.

¹ These estimates including the tables set out below have been prepared by Orca in accordance with Canadian National Instrument 43-101 standards and have not been reported in accordance with the JORC Code. A competent person has not done sufficient work to classify the resource in accordance with the JORC Code and it is uncertain that following evaluation and/or further exploration work that the estimate will be able to be reported as a mineral resource or ore reserve in accordance with the JORC Code. Orca Ore Reserve and Mineral Resource figures are stated on 100% basis.

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