"An internal review of the estimate identified a miscalculation made by an independent consultant in the conversion of lead and zinc grades into the silver-equivalent calculation," Vizsla's president and CEO Michael Konnert said.
"This, in-turn, lifted lower-grade zones above the economic cut-off, adding tonnes to the resource, but lowering the overall grade," he added.
The maiden resource estimate was announced on February 28.
Canaccord Genuity Capital Markets analyst Kevin MacKenzie said that CG expected the miscalculation will amount to "nothing more than a speed bump longer-term".
"While the optics of the restatement are admittedly not great, the results do not fundamentally change our project outlook," he said.
"This, in our view, is underscored by management's quick response in restating the estimate, and genuine commitment to resource transparency," he added.
MacKenzie noted that at the base-case 150 grammes of per tonne silver-equilvalent cut-off, the restated estimate outlines an indicated resource of 61 million ounces grading 383g/t AgEq and an inferred resource of 46Moz grading 345g/t AgEq.
Overall, this yields a global resource base of 107Moz grading 366g/t AgEq, he said.
Vizsla traded at C$2.41/share on March 2. The company had a market capitalisation of C$357.37 million.