Mithril Silver and Gold Limited (TSX-V: MSG) (ASX: MTH) (OTCQB: MTIRF) is pleased to announce an upgraded Mineral Resource Estimate for the Target 1 deposit at its flagship Copalquin Project in Durango State, Mexico.

After approximately 60,000 metres of drilling, 204 drill holes for an overall Target 1 discovery cost of less than US$20 per ounce of gold equivalent, Mithril has developed a high quality and predictive geological model that clearly defines the controls on mineralisation, resulting in high resource confidence and continuity.

Unlike a purely geological estimate, the upgraded MRE has been constrained using preliminary mining shapes and incorporates expected mining dilution, providing a more realistic representation of the material that could ultimately form a mine plan. By accounting for practical mining conditions at the resource stage, the estimate provides a stronger foundation for future mine planning, engineering studies and economic evaluation, and represents an important step in de-risking the Target 1 as it advances toward development.

Highlights

• Significant resource upgrade with total constrained and diluted Indicated and Inferred resources of 343 koz gold + 8.479 Moz silver (464 koz AuEq) and 103 koz gold + 3.398 Moz silver (151 koz AuEq), respectively. Indicated totals 3.391 Mt grading 3.15 g/t gold and 77.8 g/t silver (diluted) and Inferred totals 1.436 Mt grading 2.23 g/t gold and 73.6 g/t silver (diluted). See Table 2 for full details
• 196% increase in higher-confidence indicated gold and silver compared to previous MRE.
• 75% of total gold and silver now classified as indicated
• Resource constrained within preliminary underground mining shapes and incorporates expected mining dilution, providing a more realistic basis for future engineering and economic studies
• High confidence resource, remains open along strike and at depth with multiple opportunities for expansion
• Overall Target 1 MRE discovery cost of less than US$20 per ounce AuEq from approximately 60,000 metres of drilling in 204 drill holes
• Geological insights from Target 1 are being applied across multiple high-grade targets within the broader Copalquin epithermal system

The following Table 1 provides the highlighted base case for undiluted mineralisation reporting within the underground mining shapes (mine stope optimiser – MSO) at a cut-off grade of 1.5 g/t AuEq plus sensitivities to gold prices.

The MRE for Target 1 (Table 2) was generated from the highlighted base case in Table 1 assuming bulk underground mining method (long hole open stoping – LHOS) with mining widths averaging approximately 4 metres as presented on a diluted basis in Table 2. The MSO work identified areas where more selective underground mining methods such as cut and fill (higher cost than LHOS) could be utilised to reduce dilution and increase mined grades. The difference between the undiluted grade of 6.85 g/t AuEq (Table 1 Indicated base case) and the diluted grade of 4.26 g/t AuEq (Table 2, Total Indicate Target 1 MRE) reflects this conservative mining dilution assumption whereby lower grade mineralisation surrounding the high grade core would be extracted within geometry of a minable shape adding more tonnes and ounces at a lower average grade. More detailed mining study work will fully assess the mining methods across the Target 1 MRE.

“This resource upgrade is about much more than adding ounces. We now have a resource where three-quarters of the contained metal sits in the higher-confidence Indicated category, constrained within practical underground mining shapes and incorporating expected mining dilution,” said John Skeet, Managing Director and CEO. “That gives us a resource that is directly applicable to mine planning rather than simply a geological inventory. Combined with a discovery cost of less than US$20 per gold equivalent ounce and an underlying predictive geological model that continues to identify new mineralisation, we believe Target 1 has become one of the highest-quality pre-development underground gold-silver resources in Mexico.”

Webinar – Join Mithril management for live online seminar reviewing the most recent MRE and company update.

Date and Time: Pacific Time June 30, 2026 3:30pm, Aust Eastern Time, July 1, 2026 8:30 am

Where: https://6ix.com/event/mithril-silver-and-gold-copalquin-project-update

Table 1 Gold price sensitivity to constraining shapes, reported at 1.5 g/t AuEq cut-off (constrained and undiluted)

Notes to Table 1:

• The Table presents the results of a sensitivity analysis by varying gold prices on AuEq block model values and reports an undiluted tonnage, grade and metal content contained within the mining shapes. The scenarios as presented are not considered statement of mineral resources or reserves, and do not have demonstrated economic viability.
• AuEq calculated using metal prices of USD $3,300/oz Au and $50/oz Ag where AuEq g/t = Au g/t + (Ag g/t x (Au price/Ag price) x (Ag recovery/Au recovery)) with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples¹. An AuEq cut-off grade of 1.5 g/t was selected after applying 95% mining recovery and 5% dilution factors to the metal price and recovery values.

Table 2 Upgraded Copalquin Target 1 Mineral Resource Estimate (underground mining shape constrained & diluted)

Notes to Table 2:

1. Numbers may not add due to rounding.
2. All dollar values in United States Dollars unless otherwise noted.
3. Mineral resources were prepared in accordance with the CIM Definition Standards (2014) and Estimation of Mineral Resource and Mineral Reserve Best Practice guidelines (2019), which are materially identical to the JORC Code (2012).
4. The preparation of the mineral resource estimate was supervised by John Sims, President of Sims Resources LLC, an independent contractor and Qualified Person, and Competent Person, as a Certified Professional Geologist member with the American Institute of Professional Geologists.
5. The effective date of the estimate is June 29, 2026.
6. Inferred Mineral Resources have been estimated from geological evidence and drill core sampling and have a lower level of confidence than Measured and Indicated Mineral Resources due distance between sampled drill holes. Mineral resources are not mineral reserves and do not have demonstrated economic viability.
7. Constrained and diluted Mineral resources for Copalquin Target 1 are based on underlying metal prices of $3,300/oz Au and $50/oz Ag, unless otherwise noted.
8. AuEq g/t = Au g/t + (Ag g/t x (Au price/Ag price) x (Ag recovery/Au recovery)), and is calculated using the underlying metals prices, along with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples.²
9. Underground Resource estimates are based on economically constrained mining shapes generated using Datamine’s Mineable Shape Optimizer (MSO) algorithm and the following optimization parameters:
   • Diluted to a minimum 2 m shape width with a 92% mining recovery.
   • Metallurgical recoveries of 96% for Au and 91% for Ag, from metallurgical test work on Target 1 composite samples ¹ Longhole Open Stope mining with a total Mining+Processing+General and Administration (G&A) cost of $97.00 per tonne of material processed.
10. Mineral resources may be materially affected by environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues.

Resource Update Details

The Copalquin Target 1 resource model was prepared under the supervision of Sims Resources LLC in accordance with the CIM Definition Standards (2014) and Estimation of Mineral Resource and Mineral Reserve Best Practice guidelines (2019), which are materially identical to the JORC Code (2012).

The estimate incorporates results from 204 diamond drill holes totaling approximately 60,568 metres, including 127 drill holes totalling approximately 42,861 metres completed since the previous resource estimate. The recent drilling was primarily focused on:

• Increasing drill density within the core of the deposit to improve resource confidence;
• Extending known mineralised shoots along strike and down plunge;
• Testing interpreted extensions of high-grade structures; and
• Improving the geological model through enhanced structural understanding and dyke mapping.

The resource estimate has been prepared as a major de-risking milestone to serve as a valuable stepping stone towards future development of a mineable resource supported by an economic study. Application of the mine stope optimization process to constrain the block model by mining shapes has achieved several goals including the evaluation of realistic minimum mining widths on the deposit, evaluation of the continuity of the mineralisation along potential underground development levels and has provided understanding of a potential extractable grade that incorporates the mineralised dilution envelope surrounding the high grade core of the deposit.

An evaluation of gold price sensitivity on the mining shape constraints, on a diluted basis indicates a narrow band of output scenarios across a wide range of metal prices (Table 3). Evaluating the sensitivity scenarios on an undiluted basis (Table 1) reveals the high-grade core of the deposit that is driving the mining shapes.

With 95% of the undiluted and high grade core of the block model being captured by the mining shape constraints, there is opportunity to drill the remaining 5% of the block model to refine mineralisation boundaries for potential inclusion to future constrained mineral resource estimates.

Table 3 Gold price sensitivity to constraining shapes, reported using all contained blocks (diluted)

Notes to Table 3:

1. MSO shapes were based on long hole stope configuration with a 2.5 m minimum width, and a USD $97/t operating cost comprised of $60/t incremental mining, $25/t processing, $10/t G&A, and $2/t sustaining. Blocks were evaluated using AuEq value, using variable gold prices according to the sensitivity scenario.
2. The scenarios as presented are not considered statement of mineral resources or reserves, and do not have demonstrated economic viability.

Geological Description of Copalquin Target 1

The Copalquin project is targeting low sulfidation epithermal silver-gold mineralisation hosted in volcanic and subvolcanic rocks of Mexico’s Sierra Madre Occidental. Mapping and diamond drilling activities have identified widespread quartz veining and stockworks surrounded by haloes of argillic (illite/smectite) alteration. Veins have formed as both low-angle semi-continuous lenses parallel to the contact between granodiorite and andesite and as tabular veins in high-angle normal faults with prominent east-west, and northwest-southeast orientations. Vein and breccia thickness has been observed locally up to 30 metres wide with average widths on the order of 0.5 to 4 metres. Semi-continuous mineralisation has been intersected by drilling along a northeast trending zone from El Gallo to Refugio, Cometa, Los Pinos, Los Reyes, La Montura to Constancia and Santa Cruz, totalling almost 7 kilometres in length. A sub-parallel trend in the southern area from southwest of Apomal (Target 5) to San Manuel and to Las Brujas-El Peru provides additional exploration potential up to 6km.

Drilling at the Target 1 area has been centred on the El Refugio and La Soledad areas. Channel sampling of two small historical mine workings in these areas confirmed high grade gold and silver mineralisation was contained in pillars and mine walls. Drilling activities initiated by Mithril in 2020 confirmed broad mineralisation in these zones.

A geological model for the Target 1 area, including mineralised veins, alteration haloes, non-mineralised host rock, and post-mineral dikes, was developed in Leapfrog Geo using interval selections completed on all core drillholes available. Interval selections consider qualitative logging data, gold and silver assays, and multi-element geochemistry. Surface and underground mapping, trench sampling, and soil samples were also used to validate the interpretation but were not used in estimation. High-grade mineralised domains were modelled using a 1 g/t AuEq cutoff and were restricted to modelled vein solids derived from the lithology model. A variable orientation search strategy was applied to accurately reflect undulations in modelled veins, with search orientations driven by the nearest vein midpoint surface. Post mineral dikes cut and displace mineralised veins in several areas, disrupting vein continuity and gold-silver mineralisation. These post-mineral dikes were assigned a grade of 0.0 g/t for both gold and silver to avoid over-estimation of mineralised material. An average bulk density of 2.56 t/m3 (+/- 0.014) has been applied to the mineralised volumes based on 247 measurements in quartz breccia collected by Mithril geologists.

Block Model Estimation Methodology

Geologic and estimation domains were constructed using Leapfrog Geo v.2026.1.1, including input from geochemical analyses completed in ioGAS v.8.3. Geostatistical evaluations and Exploratory Data Analysis, including topcut selection, declustering, and variography were completed using Snowden Supervisor v.9.2. Resource estimation was prepared using Leapfrog EDGE v.2026.1.1.

A single, non-rotated 2.5×2.5×2.5m block model was prepared for this resource estimate and for use in underground Mineable Shape Optimization. Gold and silver grades from diamond drill core samples were interpolated into the block model using inverse distance cubed (“ID3”) estimation techniques. Search ellipse orientation and radii were selected based on variogram models for mineralised estimation domains, with variable search orientation applied according to the nearest vein midpoint surface in the Target 1 mineralised quartz vein and breccia model. Blocks were classified under the categories of “Indicated” and “Inferred” mineral resources, in accordance with the 2014 Canadian Institute of Mining, Metallurgy and Petroleum Standards for Mineral Resources and Mineral Reserves, Definitions and Guidelines, May 2014, which are materially identical to those used in the JORC Code (2012). The “Measured” resource category was not used in this estimate because no modern mining has been undertaken at the Project and it is therefore not possible to reconcile the estimate against production or tightly spaced data such as grade control drilling.

Mineral resources were reported below the most recent light detection and ranging topographic surface and are contained within economically constrained stope shapes generated using Datamine’s Mineable Shape Optimizer. Historical mine workings were assigned a density of 0.0 g/cm³ to ensure exclusion of mined blocks from the Mineral Resource Estimate.

Figure 1: Series of plan view maps of the Mineral Resource Estimate showing: a) AuEq grade (g/t), b) block classification, and c) mining shapes used to constrain the block model

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/11657/303420_f43a72d644e83990_001full.jpg

Figure 2: Cross- section view of El Refugio, looking east, showing the mineralised block model and the mining shape constraints used in the Mineral Resource Estimate

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/11657/303420_f43a72d644e83990_002full.jpg

Figure 3: Cross- section view of La Soledad, looking northwest, showing the mineralised block model and the mining shape constraints used in the Mineral Resource Estimate

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/11657/303420_f43a72d644e83990_003full.jpg

Advancing the Copalquin District

Target 1 represents only one of numerous mineralised targets identified within the broader Copalquin District. The Company continues to advance exploration activities across the district, including ongoing drilling at Targets 3 and 5 (Figure 5), where recent results have demonstrated the potential for additional high-grade silver and gold discoveries.

With the updated Target 1 resource now completed, Mithril intends to continue advancing engineering, metallurgical and development studies while pursuing resource growth opportunities across the district.

Two drills are currently active: one following up at Target 5 area and one testing the priority structural targets, with Target 1 westerly step out drilling to follow. Fully funded for further 12,000 metres of drilling for the remainder of 2026 aiming to progress Target 5 to an initial resource, expand Target 1 and progress the district geology model.

Figure 4: Mithril’s Copalquin and La Dura property locations in Durango State, Mexico

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/11657/303420_303420mithrilfigurefour.jpg

Figure 5: LiDAR identified historic workings across the 70km² district. Current drilling locations at Target 1, Target 3 and Target 5 with ongoing mapping and sampling plus recently completed aerial magnetic survey (report pending)

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https://images.newsfilecorp.com/files/11657/303420_f43a72d644e83990_006full.jpg

ABOUT THE COPALQUIN SILVER GOLD PROJECT

The Copalquin mining district is located in Durango State, Mexico and covers an entire mining district of 70km² containing several dozen historic silver and gold mines and workings, ten of which had notable production. The district is within the Sierra Madre Gold Silver Trend which extends north-south along the western side of Mexico and hosts many gold and silver districts.

Multiple mineralisation events, young intrusives thought to be system-driving heat sources, widespread alteration together with extensive surface vein exposures and dozens of historic mine workings, identify the Copalquin mining district as a major epithermal centre for gold and silver mineralisation.

Within 15 months of drilling in the Copalquin District, Mithril delivered a maiden JORC mineral resource estimate (the “2021 MRE”, see ASX release 17 November 2021)) at the first of several target areas (Target 1), demonstrating the high-grade gold and silver resource potential for the district. The Upgraded Target 1 Mineral Resource Estimate (effective date June 29, 2026) presented in this release has completely revised and supersedes the 2021 MRE which may no longer be relied upon.

Mithril continues to advance exploration work on the Copalquin project with two active drill rigs, and field programs that are continuously expanding the mapping coverage from approximately 23 square kilometres completed to date of the 70 square kilometres of surfaces area within the concession.

A mining study (conceptual) and metallurgical test work supports the development of the El Refugio-La Soledad resource with conventional underground mining methods indicated as being appropriate and with high silver-gold recovery to produce metal on-site with conventional processing. The average vein width is approximately 4.0 metres.

Mithril is currently exploring in the Copalquin District to expand the resource footprint, to demonstrate its multi-million-ounce gold and silver potential. Mithril has an exclusive option to purchase 100% interest in the Copalquin mining concessions by paying US$10M on or any time before 7 August 2028.

-ENDS-

Released with the authority of the Board.

For further information contact: