Interview with Marcio Fonseca, CEO of GR Silver Mining Ltd.

Our previous interview: https://www.cruxinvestor.com/posts/gr-silver-mining-tsxvgrsl-138m-raise-powers-near-term-revenue-plan-7713

Recording date: 5th September 2025

GR Silver Mining Ltd. (TSXV: GRSL) has delivered a breakthrough discovery at its San Marcial project in Sinaloa, Mexico, with drill hole SMS25-09 intersecting 75 meters at 293 g/t silver equivalent, including a bonanza-grade core of 6.4 meters at 1,915 g/t AgEq. The results extend high-grade mineralization 100 meters below the current resource area, confirming continuity of what appears to be a large, well-preserved epithermal silver system.

The discovery represents a significant geological milestone, with CEO Marcio Fonseca explaining that the company believes it is "scratching the upper portion of the system" with potential for 500+ meters of additional depth. The presence of boiling textures—a critical indicator in epithermal systems—provides confidence that high-grade mineralization continues at depth. Structural analysis reveals intersecting northwest-northeast fault systems creating 25-meter-wide mineralized shoots in porous volcanic rocks, with only 20% of the identified geophysical anomaly currently tested.

GR Silver Mining is pursuing a dual development strategy that balances near-term production potential with long-term exploration upside. The company's permitted Plomosas underground mine, which operated from 1985 to 2000, offers existing infrastructure and regulatory approvals for potential pilot-scale production within 12 months. Meanwhile, San Marcial represents substantial blue-sky potential, with the epithermal system remaining open both down-dip and laterally.

Recent financing of C$13.8 million provides 12-15 months of operational funding, with 40% allocated to bulk sampling and test mining at Plomosas and the remainder focused on resource expansion drilling at San Marcial. The company maintains three drill rigs on site and has a 52-hole drilling program pending regulatory approval, targeting a new resource model for 2026 that incorporates the expanded mineralization footprint discovered through systematic step-out drilling.

View GR Silver Mining's company profile: https://www.cruxinvestor.com/companies/gr-silver-mining

Sign up for Crux Investor: https://cruxinvestor.com