GR Silver Reports Its Best Ever Drill Results at San Marcial: 45.1 m at 1,623 g/t Ag, Including 8.25 m at 8,579 g/t Ag, in Hole SMS26-04

GR Silver reported assay results from drill hole SMS26-04, part of the 20,000-metre step-out campaign at the San Marcial deposit within the Plomosas Project. The hole returned a true-width intercept of 45.1 metres grading 1,623 g/t silver, including an exceptional high-grade sub-interval of 8.25 metres at 8,579 g/t silver, with associated lead and zinc. Mineralization is hosted in chlorite-hematite breccias at the contact of volcanic and volcano-sedimentary units, confirming a boiling zone that plunges to the southeast. The company called it the best drill results ever reported on the project, demonstrating strong continuity and validating the geological model for further resource growth.

The May 19 drill results represent a significant escalation in grade and width compared to all previous releases. Earlier step-out holes in 2026 (SMS26-03: 15.6 m at 351 g/t Ag; SMS26-01: 6.45 m at 498 g/t Ag) already indicated high-grade continuity, but SMS26-04’s 45.1 m at 1,623 g/t Ag, with sub-intervals exceeding 8,500 g/t Ag, far surpasses those grades and any historical intercepts. This confirms an exceptionally rich mineralized shoot within the broader epithermal system, with the potential to add substantial high-grade ounces to the resource base. The news materially de-risks the geological model and strengthens the case for a much larger, economically attractive deposit. The announcement comes when the stock had declined to $0.31, suggesting the market had not priced in such outstanding results. Against a market cap of ~C$158 M, a high-grade discovery of this magnitude can be a game-changer for resource growth and project economics.

GR Silver Mining is a silver-focused exploration and development company with the Plomosas Project in Mexico. The project comprises the San Marcial area (68 Moz AgEq resource) and the past-producing Plomosas Mine (66 Moz AgEq), for a combined 134 Moz AgEq. The flagship San Marcial deposit hosts epithermal silver-gold mineralization with significant grades near surface and at depth. The company holds a five‑year drilling permit and is conducting a 20,000 m step-out drilling program to expand the resource. Concurrently, it is advancing metallurgical test work and engineering studies for a Bulk Sampling Test Mining program at the permitted Plomosas underground mine, targeting a potential restart of production.