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Fortuna Establishes Presence in the Guyana Shield Through Quartzstone Earn-In Agreement

Mergers & Acquisitions Property Options & Staking

NEWS RELEASE

Fortuna Establishes Presence in the Guyana Shield Through

Quartzstone Earn-In Agreement

Vancouver, British Columbia, April 20, 2026: Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is

pleased to announce it has entered into an earn -in agreement with Qstone Inc., a private Guyanese

company, pursuant to which Fortuna may earn up to a 70% interest in the Quartzstone Project, a large

land package comprising 29,600 hectares located in the greenstone belt of north central Guyana.

Jorge A. Ganoza, President and CEO of Fortuna, commented, “We are excited to establish a presence

in the Guyana Shield, a highly prospective region with a strong history of gold discoveries.” Mr. Ganoza

continued, “The Quartzstone Project, where historical drilling has identified multiple high grade zones

of near -surface gold mineralization, is located in a prolific exploration camp, and this transaction

provides Fortuna with a staged path to unlock its potential through systematic exploration and drilling.”

Previous Drill Highlights

A total of 183 diamond core drill holes, comprising 23,190 meters, were completed between 2010 and

2017. Drilling along a five-kilometer corridor identified multiple zones of high grade near-surface gold

mineralization. Drill highlights include:

DQS-016: 27.78 g/t Au

41.10 g/t Au

89.90 g/t Au

over a width of 5.6 meters from 23.0 meters, including

over a width of 1.1 meters from 25.6 meters and

over a width of 1.0 meter from 26.7 meters

DQS-043: 4.31 g/t Au

15.58 g/t Au

12.45 g/t Au

over a width of 12.7 meters from 42.7 meters, including

over a width of 1.6 meters from 44.6 meters and

over a width of 1.3 meters from 54.1 meters

DQS-052: 12.65 g/t Au over a width of 4.0 meters from 51.6 meters

DQS-057: 15.93 g/t Au

74.72 g/t Au

81.96 g/t Au

over a width of 13.2 meters from 92.2 meters, including

over a width of 1.0 meter from 94.9 meters and

over a width of 1.0 meter from 95.9 meters

DQS-070: 10.13 g/t Au

19.33 g/t Au

16.63 g/t Au

over a width of 5.0 meters from 105 meters, including

over a width of 2.0 meters from 105 meters, and

over a width of 1.0 meter from 108 meters

DQS-071: 10.82 g/t Au

37.84 g/t Au

over a width of 6.7 meters from 89.2 meters, including

over a width of 0.8 meters from 94.2 meters

DQS-088: 9.91 g/t Au

101.58 g/t Au

over a width of 13.1 meters from 242.7 meters, including

over a width of 1.0 meter from 246.7 meters

Refer to Appendix 1 for full details of the drill holes and assay results for this historical program.

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Project location and geological setting

Figure 1: Location of Quartzstone Project, Guyana

The Quartzstone Project is located approximately 120 kilometers west of Georgetown and 35

kilometers northwest of G Mining’s Oko West project (refer to Figure 1). The Project hosts an orogenic

gold system along the contact between a granitoid complex and Lower Proterozoi c greenstone rocks

within the Guyana Shield, a geological setting known for significant gold deposits.

Local geology comprises granitoids, metavolcanic, and metasedimentary rocks, cut by a west-dipping,

north-south striking thrust and shear zone that extends over 26 k ilometers. Gold mineralization is

hosted in quartz-tourmaline-carbonate veins and breccias within a high-strain corridor up to 100 meters

wide along the principal north -south shear and associated northeast -trending structures. Drilling to

date has tested only approximately 5 kilometers of the 26 kilometer shear zone within the concession

area. Several geochemical anomalies along northeast-southwest trending cross -structures also

remain untested and will be prioritized by the exploration program.

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Planned Exploration

Fortuna’s initial exploration program, budgeted at approximately US$5.5 million, will focus on

advancing priority targets already defined at Quartzstone, while generating additional targets along

the highly prospective 26 kilometer main shear zone. Planned work includes airborne magnetic

surveys to develop a detailed structural framework, supported by high-resolution satellite imagery and

digital elevation modelling. Field programs will include infill geochemical sampling, auger drilling, and

detailed geological and regolith mapping over prospective geophysical targets and known anomalous

areas. An initial 5,000 meter diamond drilling program is planned to test historical targets and workings,

as well as priority structural corridors along the main contact and northeast-trending intersections.

Earn-in Agreement Terms

Fortuna may earn an initial 51% interest in the Quartzstone Project by completing a minimum of 60,000

meters of drilling within four years, while paying all license fees and fund ing all related expenditures.

Upon exercise of the first option, Fortuna will form a joint venture with Qstone.

Fortuna may earn an additional 19% interest in the Quartzstone Project, for an aggregate 70% interest,

by solely funding a feasibility study within three years of exercising the first option and continuing to

pay all license fees. Upon signing the Earn-In Agreement, the Company paid Qstone a non-refundable

cash option premium of US$5 million.

In addition to royalties payable to the State on gold production, the Quartzstone Project is subject to a

4.5% net smelter returns royalty in favour of a prior owner, which may be repurchased at a price to be

determined by the parties at any time.

Quality Assurance & Quality Control for previous exploration drill program

All diamond drilling (DD) drill holes started with PQ sized diameter (85 mm core), before reducing to

HQ diameter (63.5 mm core) 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 or iginal core box and

stored in a secure location at the 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 DD samples were prepared by WBDG at the in-house sample preparation facility at the Quartzstone

camp where samples were dried and crushed to 95% passing a 10-mesh screen. Following crushing,

samples were riffled to 500 gram and pulverised to 80% passing a 150-mesh screen to produce a final

50-gram pulp sample.

Prior to 2013, pulps were securely transported to either Loring Laboratories Ltd. , in Georgetown ,

Guyana, or Acme laboratory located in Santiago , Chile, for assay analysis. Samples were analy zed

by fire assay using 50 gram sample charge with atomic absorption spectroscopy finish. If the result

was >1.0 g/t Au the sample was re-assayed by fire assay with gravimetric finish.

The 2013 exploration program used the Acme Laboratory in Abidjan, Ivory Coast, and ALS Laboratory

in Lima, Peru. Acme assayed samples using the bulk leach extractable gold method with solvent

residue assayed using a standard fire assay with atomic absorption spectroscopy finish using 50 gram

sample charges. ALS used gold by bulk extended leach cyanide using 1 kilogram sample charges.

Since 2015 Activation Laboratories Canada (Actlabs), with a laboratory in Georgetown, Guyana, used

for analysis by fire assay with gravimetric finish and leachwell 500 gram sample charges . In 2016

Actlabs were used for re-analysis of rejects by leachwell 500 gram sample charges. The 2017 drilling

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was analyzed at Actlabs in Georgetown, Guyana, by metallic screens and fire assay with gravimetric

finish.

Quality control procedures included the systematic insertion of blanks, duplicates and sample

standards into the sample stream. In addition, the laborator ies inserted their own quality control

samples.

Qualified Person

Paul Weedon, Senior Vice President, Exploration for Fortuna Mining Corp., 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 conducted a site visit to the Quartzstone Project in June

2025, where mineralized intervals of drill core were examined; surface exposures of mineralization

were visited, and discussions held with geolog y staff regarding historical sampling and analytical

techniques underlying the drilling data. To further verify the data, original assay certificates were

compared to the database and independent sampl ing of core was performed that confirmed the

presence of gold in randomly selected mineralized intervals. There were no limitations to the

verification process.

About Fortuna Mining Corp.

Fortuna Mining Corp. is a Canadian precious metals mining company with three operating mines and

a portfolio of exploration projects in Argentina, Côte d’Ivoire, Mexico, and Peru, as well as the Diamba

Sud Gold Project in Senegal. Sustainability is at the core of our operations and stakeholder

relationships. We produce gold and silver while creating long -term shared value through efficient

production, environmental stewardship, and social responsibility. For more information, please visit

our website at www.fortunamining.com.

ON BEHALF OF THE BOARD

Jorge A. Ganoza

President, CEO, and Director

Fortuna Mining Corp.

Investor Relations:

Carlos Baca | [email protected] | fortunamining.com | X | LinkedIn | YouTube | Instagram | TikTok

-5-

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 pertaining to the ability of Fortuna to satisfy

the conditions to earn an initial 51% interest, and an additional 19% interest, in the Quartzstone Project;

statements regarding the ability to acquire the 4.5% NSR; statements regarding the Company’s proposed initial

exploration program, including planned drilling, camp and access upgrades , and other work ; statements about

the Company’s business strategies, plans and outlook; the Company’s plans for its mines and mineral properties;

changes in general economic conditions and financial markets; the impact of inflationary pressures on the

Company’s business and operations; the future results of exploration activities; expectations with respect to metal

grade estimates and the impact of any variations relative to metals grades experienced; assumed and future

metal prices; the merit of the Company’s mines and m ineral properties; and the future financial or operating

performance of the Company. Often, but not always, these Forward-looking Statements can be identified by the

use of words such as “estimated”, “potential”, “open”, “future”, “assumed”, “projected”, “proposed”, “used”,

“detailed”, “has been”, “gain”, “planned”, “reflecting”, “will”, “anticipated”, “estimated” “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 o r implied by the Forward-looking Statements. Such uncertainties and

factors include, among others, operational risks associated with mining and mineral processing; uncertainty

relating to Mineral Resource and Mineral Reserve estimates; uncertainty relating to capital and operating costs,

production schedules and economic returns; risks relating to the Company’s ability to replace its Mineral

Reserves; risks related to the conversion of Mineral Resources to Mineral Reserves; risks associated with mineral

exploration and project development; uncertainty relating to the repatriation of funds as a result of currency

controls; environmental matters including obtaining or renewing environmental permits and potential liability

claims; uncertainty relating to nature and climate conditions; laws and regulations regarding the protection of the

environment (including greenhouse gas emission reduction and other decarbonization requirements and the

uncertainty surrounding the interpretation of omnibus Bill C -59 and the related amendments to the C ompetition

Act (Canada); risks associated with political instability and changes to the regulations governing the Company’s

business operations; changes in national and local government legislation, taxation, controls, regulations and

political or economic developments in countries in which the Company does or may carry on business; risks

associated with war, hostilities or other conflicts, such as the Ukrainian - Russian, Iran - Israel and US, I srael -

Hamas conflicts, and the impacts they may have on global economic activity; risks relating to the termination of

the Company’s mining concessions in certain circumstances; developing and maintaining relationships with local

communities and stakeholders; risks associated with losing control of public perception as a result of social media

and other web -based applications; potential opposition to the Company’s exploration, development and

operational activities; risks related to the Company’s ability to obt ain adequate financing for planned exploration

and development activities; property title matters; risks related to the ability to retain or extend title to the

Company’s mineral properties; risks relating to the integration of businesses and assets acquired by the Company;

impairments; risks associated with climate change legislation; reliance on key personnel; adequacy of insurance

coverage; operational safety and security risks; legal proceedings and potential legal proceedings; uncertainties

relating to general economic conditions; risks relating to a global pandemic, which could impact the Company’s

business, operations, financial condition and share price; competition; fluctuations in metal prices; risks

associated with entering into commodity forward and option contracts for base metals production; fluctuations in

currency exchange rates and interest rates; tax audits and reassessments; risks related to hedging; uncertainty

relating to concentrate treatment charges and transportation costs; sufficiency of monies allotted by the Company

-6-

for land reclamation; risks associated with dependence upon information technology systems, which are subject

to disruption, damage, failure and risks with implementation and integration; labor relations issues; as well as

those factors discussed under “Risk Factors” in the Company's Annual Information Form for the fiscal year ended

December 31, 2025. 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, the accuracy of the Company’s current Mineral Resource and Mineral

Reserve estimates; that the Compan y’s activities will be conducted in accordance with the Company’s public

statements and stated goals; that there will be no material adverse change affecting the Company, its properties

or its production estimates (which assume accuracy of projected ore gr ade, mining rates, recovery timing, and

recovery rate estimates and may be impacted by unscheduled maintenance, labor and contractor availability and

other operating or technical difficulties); the duration and effect of global and local inflation; the dur ation and

impacts of geo-political uncertainties on the Company’s production, workforce, business, operations and financial

condition; the expected trends in mineral prices, inflation and currency exchange rates; that all required approvals

and permits will be obtained for the Company’s business and operations on acceptable terms; that there will be

no significant disruptions affecting the Company's 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 these 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

All 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 m ineral projects. 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 Resourc es

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.

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Appendix 1: Quartzstone historical program drill holes and assay results

HoleID Easting

(PSAD56_21N)

Northing

(PSAD56_21N)

Elev.

(m)

EOH1,2

Depth

(m)

UTM

Azimuth Dip

Depth2

From

(m)

Depth2,3

To

(m)

Drilled2,4

Width

(m)

Au

(g/t)

Hole

Type5 Area

1-1 248485.93 727799.3 97.15 160.6 132 -60 46.30 47.10 0.80 6.00 DD South West

1-1 72.30 77.80 5.50 0.81 DD South West

1-2 248435.21 727842.85 112.02 160.8 132 -60 NSI DD South West

124-1 251490.52 731180.19 151.17 170 90 -60 NSI DD Soddam

North

1-3 248545.58 727747.63 101.86 160.6 132 -60 62.80 65.80 3.00 0.67 DD South West

162-1 251706.09 734956.64 105.01 200 90 -60 NSI DD Zone 164

164-1 251677.76 735185.91 122.91 64 60 -60 NSI DD Zone 164

164-2 251853.97 735258.29 92.74 61.6 270 -60 NSI DD Zone 164

164-3 251909.89 735258.04 90.29 113 270 -60 NSI DD Zone 164

164-4 251562.46 735188.93 132.63 50 90 -60 20.50 21.50 1.00 7.84 DD Zone 164

164-5 251540.36 735188.44 134.01 180 90 -60 42.00 50.60 8.60 0.92 DD Zone 164

164-5 80.60 81.60 1.00 6.50 DD Zone 164

164-5 134.00 134.70 0.70 5.28 DD Zone 164

164-5 156.60 166.60 10.00 1.67 DD Zone 164

164-5 including 163.50 164.20 0.70 10.44 DD Zone 164

164-6 251907.73 735088.1 98.01 210 270 -60 NSI DD Zone 164

168-1 250712.52 734737.25 190.14 150 0 -90 NSI DD Regional

168-2 251271.39 734940.91 210.36 150 0 -90 NSI DD Regional

169-1 251296.38 735680.67 162.03 133.5 0 -90 NSI DD Main Pit

169-2 251225.56 735675.85 184.98 81.9 90 -60 NSI DD Main Pit

169-3 251477.76 735665.07 105.07 120 90 -60 NSI DD Main Pit

169-4 251319.08 735660.89 155.55 200 93 -60 NSI DD Main Pit

169-5 251310.67 735717.12 151.35 210 105 -60 131.60 134.60 3.00 0.62 DD Main Pit

172-1 251934.1 735934.22 101.05 100 270 -60 NSI DD Regional

172-2 251218.81 735942.28 165.48 211.5 90 -60 NSI DD Main Pit

180-1 251603.27 736764.44 119.42 176.3 90 -60 66.90 74.00 7.10 0.87 DD Blue South

180-2 251453.3 736759.74 130.53 210 90 -60 NSI DD Blue South

180-3 251719.28 736776.34 104.74 150.7 270 -60 NSI DD Blue South

184-1 251812.35 737168.4 101.78 227 90 -60 NSI DD Blue Pit

184-2 251892.61 737159.57 109.2 150 90 -60 0.00 6.50 6.50 3.87 DD Blue Pit

184-2 including 3.50 4.20 0.70 20.70 DD Blue Pit

184-3 251629.92 737171.91 106.07 182 90 -60 NSI DD Blue Pit

184-4 251704.07 737171.11 86.27 180.2 90 -60 NSI DD Blue Pit

184-6 251992.22 737168.7 90.42 110 270 -60 NSI DD Blue Pit

190-1 252090.47 737729.98 89.76 205 90 -60 NSI DD Intermediate

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HoleID Easting

(PSAD56_21N)

Northing

(PSAD56_21N)

Elev.

(m)

EOH1,2

Depth

(m)

UTM

Azimuth Dip

Depth2

From

(m)

Depth2,3

To

(m)

Drilled2,4

Width

(m)

Au

(g/t)

Hole

Type5 Area

192-1 252345.49 737965.12 90.92 201 260 -60 NSI DD Intermediate

196-1 251798.66 738367.11 88.81 161 90 -60 NSI DD Eikle

196-2 251710.39 738367.34 112.11 209 90 -60 NSI DD Eikle

196-3 252144.73 738368.56 103.71 239 270 -60 6.50 9.50 3.00 2.32 DD Eikle

196-3 117.00 122.50 5.50 0.83 DD Eikle

196-3 including 117.00 117.50 0.50 5.13 DD Eikle

196-4 252223.95 738367.21 93.46 167 270 -60 NSI DD Eikle

196-5 252063.75 738365.43 121.3 185 270 -60 3.00 4.00 1.00 8.20 DD Eikle

196-5 52.50 53.00 0.50 28.40 DD Eikle

196-5 127.50 128.00 0.50 6.63 DD Eikle

197-1 251845.41 738474.78 87.23 95 90 -60 NSI DD Eikle

197-2 252077.65 738430.53 104.85 130 260 -60 4.00 7.00 3.00 0.95 DD Eikle

197-3 252149.1 738435.35 102.82 245 260 -60 63.80 65.00 1.20 5.20 DD Eikle

197-3 207.50 208.80 1.30 6.10 DD Eikle

198-1 251844.59 738556.69 90.46 179 90 -60 NSI DD Eikle

198-10 251902.05 738553.15 106.2 40.1 90 -60 NSI DD Eikle

198-11 251894.77 738590.02 107.19 50.4 90 -60 NSI DD Eikle

198-2 251769.13 738548.84 98.61 200 90 -60 87.00 90.00 3.00 1.22 DD Eikle

198-2 103.00 106.00 3.00 10.63 DD Eikle

198-2 including 105.00 106.00 1.00 15.90 DD Eikle

198-2 117.00 121.00 4.00 4.09 DD Eikle

198-2 including 120.00 121.00 1.00 15.10 DD Eikle

198-3 251691.33 738540.79 84.34 221 90 -60 NSI DD Eikle

198-4 251622.14 738539.51 84.93 260 90 -60 NSI DD Eikle

198-5 252131.79 738548.22 98.14 200 270 -60 NSI DD Eikle

198-6 252049.57 738551.3 89.1 179 270 -60 NSI DD Eikle

198-7 251535.84 738548.09 98.1 130 90 -60 NSI DD Eikle

198-8 251449.61 738555.44 109.37 190 90 -60 NSI DD Eikle

198-9 251893.31 738507.63 105.66 45.1 90 -60 NSI DD Eikle

199-1 251874.94 738644.74 118.26 89 90 -60 NSI DD Eikle

199-2 251907.45 738644.86 119.08 145 90 -60 NSI DD Eikle

200-1 251865.58 738771.43 91.14 152 90 -60 59.00 64.25 5.25 0.76 DD Eikle

200-2 251784.8 738765.72 96.85 167 90 -60 145.60 146.10 0.50 9.77 DD Eikle

200-3 251650.63 738763.53 121.69 248 90 -60 235.00 236.50 1.50 8.54 DD Eikle

200-4 252010.14 738771.06 99.79 148 270 -60 NSI DD Eikle

2-1 248662.96 727975.56 127.22 160.6 132 -60 NSI DD South West