GR Silver Mining (TSXV:GRSL) - Pitch Perfect, October 2025

Key Concepts

• GRCA Miner Mining: The company presenting the update.
• Pomosus Project (Sinaloa, Mexico): The primary project location.
• Summer Area: A specific drilling target within the Pomosus project.
• Plomos Mine: A historic mine being re-evaluated.
• Silver Equivalent (AgEq): A metric used to combine the value of silver and gold.
• Geophysical Anomaly: An area identified by geophysical surveys as potentially containing mineralization.
• High-Grade Silver: Mineralization with a significant concentration of silver.
• Wide Intersections: Drill core samples showing mineralization over substantial widths.
• Resource Estimation: The process of quantifying the amount of mineralized material.
• Book Sampling Test Mining: A method of extracting samples to assess the viability of mining.
• Pilot Plant: A small-scale processing facility used to test mining and metallurgical processes.
• Synergies: Potential benefits from integrating operations between different sites.
• Underground Development: Tunnels and other structures created within a mine.

Pomosus Project Update: Summer Area Drilling

GRCA Miner Mining is providing an update on its activities in Sinaloa, Mexico, specifically at the Pomosus project, with a focus on the Summer area. The company is currently drilling at the Summer area and has encountered significant high-grade silver mineralization with wide intersections.

• Drilling Progress: Two drill rigs are currently on-site, with plans to increase this number in the coming months and significantly expand the program next year, contingent on capital raising. The company is fully funded for the next 12 to 15 months.
• Geophysical Anomaly: The Summer area is characterized by a large geophysical anomaly, of which only 20% has been drilled to date.
• Discovery Magnitude: The discovery is notable for its width, averaging 25 meters in thickness.
• Mineralization Continuity: Extensive study of the rocks has confirmed the continuity of mineralization from the initial discovery hole.
  • Hole 9: Intersected 100 meters at 308 grams per ton (g/t) silver.
  • Step-down Hole: Located approximately 300 meters deeper, this hole intersected 75 meters at 260 g/t silver.
• Resource Expansion Potential: This expansion of the mineralization footprint is expected to lead to a significantly larger resource estimate in the upcoming resource update, a major catalyst for the company next year.
• Current Resource: The company currently holds 134 million ounces of silver equivalent, with 68 million ounces attributed to the Summer area.
• Silver Dominance: The Summer project is predominantly silver (85%), which is uncommon in Mexico where most deposits are polymetallic.
• Future Drilling:
  • Holes 11 and 12 are being prepared for laboratory analysis, representing further step-out drilling in the same concept as Hole 9. News on these holes is anticipated by mid-November.
  • Hole 13 and potentially one more hole are planned before the end of the year to continue expanding the mineralization footprint at Summer.
  • A significantly larger drilling program is planned for next year to at least double the mineralization footprint, in preparation for a resource estimation by mid-next year.

Plomos Mine Re-evaluation: Book Sampling Test Mining

GRCA Miner Mining has also initiated book sampling test mining at the historic Plomos mine, located just 5 kilometers from the Summer area.

• Strategic Location: The proximity of Plomos to Summer (5 km) allows for potential synergies and integration, facilitated by a good road connection.
• Historic Asset: The Plomos mine was shut down in 2001 and retains existing infrastructure, including underground development. The company possesses the necessary permits to operate.
• Underexplored Zones: The re-evaluation has identified high-grade silver and gold zones within the mine that were not fully captured in the 2023 resource estimation. This presents an opportunity to incorporate these into an updated resource and delineate them for future extraction.
• Access and Potential:
  • There are 21 accessible areas within the underground mine via tunnels.
  • The mine is described as wide and extensively developed.
  • Stockpiles of material have been encountered that could be attractive for feeding a future pilot plant.
• Infrastructure Investment: The historic mine represents a significant investment, with 7.44 kilometers of underground development.
• Data Utilization: The company plans to leverage existing drilling data and the established underground infrastructure to define material for a pilot plant, for which engineering studies are underway.
• Selective Mining Approach: The current intersections are yielding grades in the range of kilos of silver equivalent. The company is adopting a more selective approach, potentially starting with a 250 tons per day operation, with the capacity to increase to 600 tons per day as permitted.
• Attractive Grades: Intersections of 2,000, 3,000, and even 7,000 g/t silver equivalent are being encountered, making this a highly attractive scenario for capturing value in the current silver market.
• Metallurgical Testing: Methodological test work is in progress to confirm the viability of processing the extracted material.

Key Takeaways and Conclusion

The main takeaways from GRCA Miner Mining's update are:

1. Active Drilling and Discovery: The company is actively drilling at the Summer area of the Pomosus project, encountering wide, high-grade silver mineralization with significant potential to materially increase the existing resource.
2. Financial Stability: GRCA Miner Mining is fully funded for the next 12 to 15 months, providing the necessary capital for ongoing drilling at Summer and the development of the pilot plant and book sampling at Plomos.
3. Plomos Mine Potential: Book sampling and test mining at the historic Plomos mine are yielding attractive silver and gold grades, identifying new potential sources of material to feed a future pilot plant. The proximity to Summer offers synergistic opportunities.

The company is focused on expanding its resource base through aggressive drilling and exploring the value of its historic assets through targeted sampling and pilot plant development.