Fortuna intersects 88 g/t Au over 3.5m at the Séguéla Mine and provides exploration update

VANCOUVER, Dec. 12, 2023 - Fortuna Silver Mines Inc. (NYSE: FSM) (TSX: FVI) is pleased to provide an update on its exploration programs at the Séguéla Mine in Côte d'Ivoire, the recently acquired Diamba Sud Gold Project in Senegal, and the San Jose Mine in Mexico.

Exploration program highlights

Badior prospect, Séguéla Mine, Côte d'Ivoire:

Ancien deposit, Séguéla Mine, Côte d'Ivoire:

Sunbird deposit, Séguéla Mine, Côte d'Ivoire:

Paul Weedon, Senior Vice President of Exploration at Fortuna, commented, "With the successful commissioning and ramp-up of the Séguéla Mine, the exploration focus has been directed towards the regional potential, featuring the emerging Badior prospect. Recent results include drill hole SGRC1683 intersecting 17.3 g/t Au over an estimated true width of 6.3 meters. In addition, the exploration teams are building the foundation for potential long term underground mining at the Ancien and Sunbird deposits, encouraged by results such as drill hole SGRD1661 intersecting 22.9 g/t Au over an estimated true width of 15.4 meters at Ancien."

Diamba Sud Gold Project, Senegal:

Mr. Weedon continued, "Exploration drilling at the recently acquired Diamba Sud Gold Project has returned very encouraging results from the initial confirmatory drilling at Area A, with results such as drill hole DSR490 intersecting 3.1 g/t Au over an estimated true width of 29.7 meters from 7 meters, while hole DSR487 highlights the potential to increase the overall footprint of the Area A prospect with an interval of 2.3 g/t Au over an interval of 15.3 meters, extending beyond the historic mine design limit. With the team on the ground operating well after the conclusion of the Diamba Sud acquisition, I am very happy with the progress as we look forward to advancing the project in 2024."

Yessi vein, San Jose Mine, Mexico:

Mr. Weedon also highlighted the continuing work at the San Jose Mine where drilling to define the recently discovered Yessi vein has provided further insights into the regional structural controls with encouraging results, including 1,431 g/t Ag Eq over an estimated true width of 1.1 meters and a further 250 g/t Ag Eq over an estimated true width of 4 meters from SJO-1430, and 545 g/t Ag Eq over an estimated true width of 17.0 meters from SJOM-1428. "The structural complexity of the Yessi vein helps validate the wider regional structural understanding and highlights opportunities for additional near-mine exploration targets."

Séguéla Mine, Côte d'Ivoire

Drilling for increased geologic confidence and understanding of key high-grade controls at the Badior prospect was recently concluded, with 8 holes drilled totalling 1,691 meters (refer to Figure 1). Drilling has broadly outlined a gently northerly plunging high-grade lode which remains open at depth, with drill hole SGRD1689 intersecting 10.7 g/t Au over 2.1 meters from 159 meters downhole. The interpreted northerly plunge is unusual for mineralization at Séguéla which typically demonstrates a shallow to moderate southerly plunge, and which may represent a new or antithetic structural control. Further work is planned for 2024.

Figure 1: Badior long-section showing select recent results (looking west)

At Ancien, 9 holes for a total of 3,258 meters were completed (refer to Figure 2). This short program was designed to improve the understanding of the structural controls on the high-grade lodes hosting multiple intervals such as those intersected in drill holes SGRD1661 and SGRD1663. This increased geological confidence and understanding will help support an evaluation of the underground mining potential at Ancien, where the deposit remains open at depth. Further work is planned for 2024.

Figure 2: Ancien long-section showing select recent results (looking west)

At Sunbird, a comprehensive infill drilling program consisting of 47 holes totaling 11,075 meters, was completed in August 2023 (refer to Fortuna news release dated August 8, 2023). The infill drilling was followed by a program to continue testing the extent of mineralization. Results were received for 8 holes totalling 2,100 meters completed in the southern section of the deposit (refer to Figure 3). This short program was designed to improve the understanding of the structural controls projected a further 200 meters down-plunge from the last drilling sections with encouraging results including SGRD1695 intersecting 5.0 g/t Au over an estimated true width of 14.7 meters from 341 meters downhole. This increased geological confidence and understanding will help support an evaluation of the underground mining potential at Sunbird, where the deposit remains open at depth. Further work is planned for 2024.

Refer to Appendix 1 for full details of the Séguéla drill holes and assay results.

Figure 3: Sunbird long-section showing select recent results (looking west)

Diamba Sud Gold Project, Senegal

At Diamba Sud, a 10,945-meter, three-drill rig drilling program started on October 8, 2023, with 34 holes completed for 4,976 total meters drilled to date. The objectives of the program are as follows:

• Selected confirmatory drilling of Area A, Area D, and Karakara to improve resource confidence
• Drilling to test for extensions to the existing historic resource in support of project development and advancing further studies in 2024
• Advancing prospective areas such as Gamba Gamba North, Southern Arc, Western Splay,
  Area A North, and others
• Improved understanding of key geological controls including controlling structures, favorable lithologies, alteration and secondary enrichment zones

The Area A prospect is structurally complex with interpreted supergene mineralization overlaying primary mineralization preferentially hosted in a broad sedimentary package, which has been intersected by steeper mineralized structures and folding. Mineralization remains open along strike and at depth, as demonstrated by drill hole DSR490 intersecting 1.3 g/t Au over an estimated true width of 7.2 meters from 176 meters, and an additional 1.0 g/t Au over an estimated true width of 18.9 meters from 188 meters, extending mineralization beyond the historic pit design (refer to Figures 4 - 6).

This program will continue for the remainder of 2023 with additional drilling programs, including regional exploration and target generation budgeted for 2024.

Refer to Appendix 2 for full details of the Diamba Sud Gold Project drill holes and assay results.

Figure 4: Diamba Sud Gold Project location plan

Figure 5: Area A drilling location plan

Figure 6: Area A cross section A - A'; refer to Figure 5 for location

Figure 7: Area A cross section B - B'; refer to Figure 5 for location

San Jose Mine, Mexico

Drilling of the recently discovered Yessi vein (refer to Fortuna news release filed on SEDAR+ on September 5, 2023) has continued with the objective of defining the structural relationship between the Yessi vein and the various systems at the San Jose Mine with 13 additional holes completed for a total of 7,444 meters.

Initially interpreted as an approximately north-south trending vein, recent drilling has highlighted the likelihood of the Yessi vein forming a north-northwest orientated link structure between the Victoria Mineralized Zone and an as yet undefined structure further eastwards, an interpretation supported by regional geophysical data. Drilling has been re-orientated to better target this revised orientation, with drilling continuing.

Mineralization remains open along strike to the southeast, whereas to the northwest the Yessi vein intersects the Victoria Mineralized Zone.

Refer to Appendix 3 for full details of the Yessi vein drill holes and assay results.

Figure 8: Plan view of the Yessi vein, San Jose Mine. Refer Figure 9 for the long-section view (A-A').


Figure 9: Long section view (A-A') of the Yessi vein, San Jose Mine

Quality Assurance & Quality Control (QA - QC)

Séguéla Mine, Côte d'Ivoire and Diamba Sud Gold Project, Senegal

All drilling data completed by the Company utilized the following procedures and methodologies. All drilling was carried out under the supervision of the Company's personnel.

All RC drilling used a 5.25-inch face sampling pneumatic hammer with samples collected into 60-liter plastic bags. Samples were kept dry by maintaining enough air pressure to exclude groundwater inflow. If water ingress exceeded the air pressure, RC drilling was stopped, and drilling converted to diamond core tails. Once collected, RC samples were riffle split through a three-tier splitter to yield a
12.5% representative sample for submission to the analytical laboratory. The residual 87.5% samples were stored at the drill site until assay results were received and validated. Coarse reject samples for all mineralized samples corresponding to significant intervals are retained and stored on-site at the
Company-controlled core yard.

All diamond drilling (DD) drill holes at Séguéla were drilled with HQ sized diamond drill bits, whereas DD holes at Diamba Sud started with HQ sized diameter, before reducing to NQ diameter diamond drill bits on intersecting fresh rock. The core was logged, marked up for sampling using standard lengths of one meter or to a geological boundary. Samples were then cut into equal halves using a diamond saw. One half of the core was left in the original core box and stored in a secure location at the Company core yard at the project site. The other half was sampled, catalogued, and placed into sealed bags and securely stored at the site until shipment.

All Séguéla RC and DD core samples were shipped to ALS Laboratories' preparation laboratory in Yamoussoukro for preparation and then, via commercial courier, to ALS's facility in Ouagadougou, Burkina Faso for finishing. All Diamba Sud RC and DD samples were transported to ALS's preparation laboratory in Kedougou, before also being transported via commercial courier, to ALS's facility in Ouagadougou. Routine gold analysis using a 50-gram charge and fire assay with an atomic absorption finish was completed for all samples. Quality control procedures included the systematic insertion of blanks, duplicates, and sample standards into the sample stream. In addition, the ALS laboratory inserted its own quality control samples.

San Jose Mine, Mexico

All diamond drilling (DD) drill holes at San Jose were drilled with either NQ sized diameter (drilled from underground) or HQ sized diamond drill bits reducing to NQ sized diameter with greater depth. Following detailed geological and geotechnical logging, all diamond drill core samples are split on-site by diamond sawing. One half of the core is submitted to the internal laboratory located in the CMC facilities. The CMC laboratory has been accredited by the Standard Council of Canada (ISO 17025: 2017) for preparation, drying, gravimetry, fire assay, Inductively Coupled Plasma and Atomic Absorption processes. The remaining half core is retained on-site for verification and reference purposes. Following preparation, the samples are assayed for gold and silver by standard fire assay methods and for silver and base metals by Inductively Coupled Plasma and as well as three acid digestion at the same internal laboratory. The QA - QC program includes the blind insertion of certified reference standards and assay blanks at a frequency of approximately 1 per 20 normal samples as well as the inclusion of duplicate samples for verification of sampling and assay precision levels.

Qualified Person

Paul Weedon, Senior Vice President of Exploration for Fortuna Silver Mines Inc., is a Qualified Person as defined by National Instrument 43-101 being a member of the Australian Institute of Geoscientists (Membership #6001). Mr. Weedon has reviewed and approved the scientific and technical information contained in this news release. Mr. Weedon has verified the data disclosed, including the sampling, analytical and test data underlying the information or opinions contained herein by reviewing geochemical and geological databases and reviewing diamond drill core. There were no limitations to the verification process.

About Fortuna Silver Mines Inc.

Fortuna Silver Mines Inc. is a Canadian precious metals mining company with five operating mines in Argentina, Burkina Faso, Côte d'Ivoire, Mexico, and Peru. Sustainability is integral to all our operations and relationships. We produce gold and silver and generate shared value over the long-term for our stakeholders through efficient production, environmental protection, and social responsibility. For more information, please visit our website.

ON BEHALF OF THE BOARD

Jorge A. Ganoza
President, CEO, and Director
Fortuna Silver Mines Inc.

Investor Relations:

Carlos Baca | info@fortunasilver.com | www.fortunasilver.com | X | LinkedIn | YouTube

Forward-looking Statements

This news release contains forward-looking statements which constitute "forward-looking information" within the meaning of applicable Canadian securities legislation and "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995 (collectively, "Forward-looking Statements"). All statements included herein, other than statements of historical fact, are Forward-looking Statements and are subject to a variety of known and unknown risks and uncertainties which could cause actual events or results to differ materially from those reflected in the Forward-looking Statements. The Forward-looking Statements in this news release include, without limitation, statements about the potential to increase the overall footprint of the Area A prospect and the Company's plans for the Diamba Sud Gold Project in 2024; statements regarding potential long term underground development at Ancien and at Sunbird at the Séguéla Mine; the Company's plans to conduct further work at Ancien and at Sunbird during 2024; the Company's objectives for the current drilling program at the Diamba Sud Gold Project and expectations regarding additional drilling programs budgeted for 2024; the Company's business strategy, plans and outlook; the merit of the Company's mines and mineral properties; mineral resource and reserve estimates; timelines; the future financial or operating performance of the Company; expenditures; approvals and other matters. Often, but not always, these Forward-looking Statements can be identified by the use of words such as "estimated", "potential", "open", "future", "assumed", "projected", "used", "detailed", "has been", "gain", "planned", "reflecting", "will", "containing", "remaining", "to be", or statements that events, "could" or "should" occur or be achieved and similar expressions, including negative variations. Forward-looking Statements involve 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 results, performance or achievements expressed or implied by the Forward-looking Statements. Such uncertainties and factors include, among others, changes in general economic conditions and financial markets; changes in prices for silver, gold and other metals; the timing and success of the Company's proposed exploration programs; technological and operational hazards in Fortuna's mining and mine development activities; risks inherent in mineral exploration; fluctuations in prices for energy, labour, materials, supplies and services; fluctuations in currencies; uncertainties inherent in the estimation of mineral reserves, mineral resources, and metal recoveries; the possibility that the ruling in favor of Compañia Minera Cuzcatlan S.A. de C.V. to reinstate the environmental impact authorization at the San Jose Mine will be successfully appealed; the Company's ability to obtain all necessary permits, licenses and regulatory approvals in a timely manner; governmental and other approvals; political unrest or instability in countries where Fortuna is active; labor relations issues; as well as those factors discussed under "Risk Factors" in the Company's Annual Information Form for the financial year ended December 31, 2022. Although the Company has attempted to identify important factors that could cause actual actions, events, or results to differ materially from those described in Forward-looking Statements, there may be other factors that cause actions, events or results to differ from those anticipated, estimated or intended. Forward-looking Statements contained herein are based on the assumptions, beliefs, expectations and opinions of management, including but not limited to expectations regarding the results from the exploration programs conducted at the Séguéla Mine, the San Jose Mine, and the Diamba Sud Gold Project; expected trends in mineral prices and currency exchange rates; the accuracy of the Company's information derived from its exploration programs at the Company's mineral properties; current mineral resource and reserve estimates; the presence and continuity of mineralization at the Company's properties; that the Company's activities will be in accordance with the Company's public statements and stated goals; that there will be no material adverse change affecting the Company or its properties; that all required approvals will be obtained; that there will be no significant disruptions affecting operations and such other assumptions as set out herein. Forward-looking Statements are made as of the date hereof and the Company disclaims any obligation to update any Forward-looking Statements, whether as a result of new information, future events or results or otherwise, except as required by law. There can be no assurance that Forward-looking Statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, investors should not place undue reliance on Forward-looking Statements.

Cautionary Note to United States Investors Concerning Estimates of Reserves and Resources

Reserve and resource estimates included in this news release have been prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") and the Canadian Institute of Mining, Metallurgy, and Petroleum Definition Standards on Mineral Resources and Mineral Reserves. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for public disclosure by a Canadian company of scientific and technical information concerning mineral projects. Unless otherwise indicated, all mineral reserve and mineral resource estimates contained in the technical disclosure have been prepared in accordance with NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards on Mineral Resources and Reserves. Canadian standards, including NI 43-101, differ significantly from the requirements of the Securities and Exchange Commission, and mineral reserve and resource information included in this news release may not be comparable to similar information disclosed by U.S. companies.

Appendix 1: Séguéla Mine, Côte d'Ivoire

Notes:

1. EOH: End of hole
2. NSI: No significant intercepts
3. ETW: Estimated true width
4. Depths and widths reported to nearest significant decimal place

Appendix 2: Diamba Sud Gold Project, Senegal

Notes:

1. EOH: End of hole
2. NSI: No significant intercepts
3. ETW: Estimated true width
4. Depths and widths reported to nearest significant figure

Appendix 3: Yessi vein, San Jose Mine, Mexico

Notes:

1. EOH: End of hole
2. NSI: No significant intercepts
3. ETW: Estimated true width
4. Ag Eq is calculated using a factor of 80:1 using metal prices of US$1,950/oz for gold with 90% metallurgical recovery and US$24.5/oz for silver with 91% metallurgical recovery
5. Depths and widths reported to nearest significant decimal place