San Marcial Data Package

Data Verification

GR Silver Mining 2019-2025 diamond drill core logging and sampling programs were conducted following strict quality assurance and quality control protocols in accordance with industry’s best practices. GR Silver Mining drillhole sizes are HQ, NQ and BQ with most drill holes reporting good recoveries. In the footwall and hanging wall of the mineralized zones, recoveries averaged 96%, while within the mineralized zones, recoveries were 92% to 94%. All the core was taken to the Plomosas Camp where GR Silver Mining geologists cleaned the core, collected geotechnical data and logged alteration, lithology, mineralization and structural data. The GR Silver Mining geologist’s mark all sampling intervals for assay analyses, and inserted QA/QC samples (Certified Reference Material [CRM], coarse blanks and field duplicates) at regular intervals along the core, using geological and structural features as a guide. In the absence of zones of interest, QC samples were inserted every six samples. The average sample length for the diamond drill-hole samples was 1.0 m, with 95% of the samples ≤2.0m. The core was photographed both wet and dry once geologists completed core logging and sample markings. After taking pictures of the core, it is transferred to the core cutting technician, who cuts it lengthwise in half with a diamond disc cutter. One half of the core is placed in a plastic bag duly labelled for shipment to a certified laboratory for geochemical analysis and the other part is kept back in the core box for future reference with the purpose that the half sent and the half preserved are representative, if the core is oriented, the reference line a is preserved for future reference. Finally, the specific weight is measured in a 15 cm sample, every 10 m of the nucleus.

The QA/QC protocols include the use of blanks, standards and duplicates (pulp and coarse) in each batch of 50 samples GR Silver includes 3 targets, 2 Certified Reference Materials and 5 duplicate samples, thus representing 20% of control sample input. QP is of the opinion that the safety, sample preparation, and analysis procedures used comply with the standards for Mineral Resource Estimation.

GR Silver Mining samples between 2020 and 2025 were sent to SGS de Mexico, S.A. de C.V. laboratory facilities in Durango, Mexico. There, gold, silver and 32 elements were analyzed by ICP-AES and the values above the limits were retested by fire test and gravimetric finishing. SGS is an internationally recognized laboratory for its high standards of quality control and management, and both its laboratories in Durango and Burnaby are ISO/IEC 17025 certified. Refer to the NI 43-101 Technical Report dated May 3^rd, 2023, filed under GR Silver Mining on SEDAR+ at www.sedarplus.ca for full disclosure of the sample preparation process.

The database contains all the exploration drillholes that have been used for the San Marcial 2023 resource and surrounding area of which includes the relevant historical drill holes. All historical diamond drill holes are of HQ and NQ sizes. Throughout the different exploration programs, the samples have been processed and analyzed by different laboratories of recognized international prestige. In 2002, all samples were sent to Chemex's preparation facility in Guadalajara. For the 2008 drilling program, samples were sent to International Plasma Labs (IPL) in Hermosillo for crushing and pulverization, and subsequently to the IPL laboratory in Richmond, Canada, for analysis. Subsequently, all samples have been sent for preparation and analysis to the SGS laboratory in Durango.

In 2022, GR Silver Silver Mining resampled 15 holes that had originally been sampled by Gold-Ore Resources Ltd. Initial sampling used longer intervals that did not adequately represent variability within the mineralized unit at San Marcial. GR Silver Mining reduced the length of the intervals to 1 meter, replacing the previous intervals of 3 meters. In total, 448 new samples replaced the original 157 Gold-Ore Resources Ltd samples.

Collar location and GPS location of historic drill holes were first collected by company geologists using a hand-held GPS unit for initial localization. Additionally, an independent surveyor was used to validate the location of all the drill holes. GR Silver Mining was able to confirm all the historic drill hole locations. The collar locations of the drill holes are given relative to WGS 84 / UTM Zone 13N.

Historic QA/QC data have been verified wherever possible by reviewing original sources and running re-sampling programs to ensure accuracy for the database. For additional details or information regarding the exploration results, interpretations, drilling results, QA/QC measures, analytical procedures, please refer to GR Silver Mining news releases between 2019 to 2025 filed on SEDAR+ at www.sedarplus.com.