Fortuna Silver Mines Inc. (NYSE: FSM) (TSX: FVI) is pleased to provide an update on its Yessi vein exploration program at the San Jose Mine in Mexico.

Paul Weedon, Senior Vice President of Exploration, commented, “Drilling on the Yessi vein, since the initial discovery hole in August 2023, has continued to establish a well-defined system, with recent results such as 1,327 g/t Ag Eq over an estimated true width of 3.0 meters from 604.85 meters in SJO-1444 and 1,036 g/t Ag Eq over an estimated true width of 8.1 meters including 2,910 g/t Ag Eq in SJO-1460 highlighting the potential for high-grade shoots. In addition, wide intervals such as the 179 g/t Ag Eq over an estimated true width of 17.5 meters in SJO-1455A highlight the potential for broad zones of mineralization”.

Yessi vein drilling highlights include:

Drilling on the Yessi vein has continued with the dual objectives of firstly testing for the limits of the Yessi vein and secondly infilling the drill spacing to support initial resource estimations and mining studies. The Yessi vein has now been successfully drill tested over a 350-meter strike and a 450-meter vertical profile where it remains open up- and down-dip, as well as along strike to the southeast. The current phase of the program consisted of 10 additional holes for a total of 6,622 meters.

Geological and structural logging of the drill core has confirmed the vein geometry as trending north-northwest, intersecting and merging with the north-south orientated Victoria Mineralized Zone towards the west. Evidence is also emerging of higher-grade shoots within the structure demonstrating a moderate south-easterly plunge and often associated with high gold grades. Vein development is consistently associated with extensive alteration and brecciation with veining characterised by fine veinlets and fragments suggesting several phases of emplacement.

Additional drilling with three drill rigs will continue to test the depth, strike and infill of the current Yessi vein extent. Refer to Appendix 1 for full details of the Yessi vein drill holes and assay results.

Figure 1: Yessi vein plan view

Figure 2: Yessi vein long section (looking south)

Quality Assurance & Quality Control

San Jose Mine, Mexico

All diamond drilling (DD) drill holes at the San Jose Mine were drilled with either NQ sized diameter 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 at the San Jose Mine. The laboratory at the mine 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.

Appendix 1: Yessi vein, San Jose Mine, Mexico

^{Notes:
1.  EOH: End of hole
2.  Ag Eq 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
3.  Vein: HW – Yessi vein hanging wall, Yv – Yessi vein main
4.  NSI: No significant interval
5.  All holes were drilled using diamond drilling tail
6.  Depths and widths reported to nearest significant decimal place}