Interview with Eric Zaunscherb, President & CEO of GR Silver Mining Ltd.
Our previous interview: https://www.cruxinvestor.com/posts/gr-silver-mining-tsxvgrsl-drilling-and-pilot-plant-strategy-support-growth-10136
Recording date: 23rd September 2026
GR Silver Mining Ltd. (TSXV:GRSL, OTCQX:GRSLF) is a Mexico-focused silver explorer that owns 100% of the Plomosas Project on the Sinaloa-Durango border. The project combines two assets with different roles. San Marcial is a silver discovery that hosts 46 Moz of indicated and 14 Moz of inferred silver under the 2023 resource estimate. The Plomosas Mine is a past producer that operated from 1986 to 2000 and now serves as a potential bulk sampling site. President and CEO Eric Zaunscherb has taken on direct responsibility for the Mexican business following the death of founder Marcio Fonseca.
The central development in 2026 is hole SMS26-04, which returned 45.1 m true width at 1,623 g/t silver, including 8.25 m at 8,579 g/t silver. Zaunscherb said the result matters most because it confirms the company's geological model. Mineralising fluids from an intrusive body broke up an overlying breccia. Metal was deposited in dilation zones where cross-cutting structures intersect it. The hole was 99.8% silver by value, compared with roughly 90% for the 2023 resource.
Rather than rushing out an early resource to showcase the hole, the company is tightening drill spacing around it from 100 m to 45 m. That aims to bring the zone into the indicated category for the resource update targeted for the first half of 2027. The 20,000 m programme is behind plan, with about 7,000 m completed after security issues and a difficult rainy season. GR Silver is spending about $1 million upgrading road access from Durango and plans to add rigs.
At Plomosas, SEMARNAT has ruled that no new environmental impact authorisation is required. Zaunscherb prefers toll milling or selling material at the mine gate over building a pilot plant, citing lower capital, a shorter timeline and lower execution risk. Pilot plant engineering nonetheless remains among the company's listed catalysts. Output would be limited to 60 to 100 tonnes per day by available power. The strategic value is social licence. Restoring local employment in a very poor area could build goodwill that carries over to San Marcial, 5 kilometres to the south. Management believes this could shorten San Marcial's five-to-seven-year path to potential cash flow by one or two years.
The company held C$26 million in cash and expects further proceeds from in-the-money warrants averaging C$0.26. Zaunscherb noted that the stock trades as a silver proxy. Longer term, GR Silver plans to permit an access tunnel at San Marcial, which could enable underground drilling from later 2028. Plomosas would produce lead and zinc concentrates, while San Marcial points to a Merrill-Crowe circuit producing doré.
On corporate strategy, parties are in the data room, and management is also reviewing acquisitions that could diversify risk within Mexico. Key risks are security, access, development capital and silver price sensitivity. Key watch-items are pending assays, drilling pace and the H1 2027 resource update.
View GR Silver Mining's company profile: https://www.cruxinvestor.com/companies/gr-silver-mining
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