Plomosas

On February 5, 2026, GR Silver Mining Ltd. (“GR Silver”) announced positive results from its metallurgical test work studies conducted as part of the Bulk Sampling Test Mining (“BSTM”) program at Plomosas. Sampled and composite feed grades in zones targeted for the BSTM in the historical Plomosas Mine produced concentrates that were within acceptable commercial specifications with no concerns over potential penalties or deleterious elements. GR Silver stated that the key objective for these studies was to support basic engineering and design of a pilot plant as part of ongoing de-risking efforts to potentially bring the historical Plomosas Mine back into production. External independent engineers have been engaged to integrate the test work data into preliminary engineering, design and costing studies, which are being used to source alternatives for a range of pilot plant capacities. The external independent engineering team has initiated assessment of potential options to secure key equipment or a full modular pilot plant in Mexico.