La Republica was reported to have been the highest grade silver producer in Mexico at the time of its closure in 1911 due to the advent of the Mexican Revolution. By 1908 the mine was reported to have produced more than 5,000,000 ounces of silver, at high grades. The average mill head grade of ore above the 166 foot (50.6 metre; "m") level, calculated in late 1906, was 132.6 ounces per ton silver (4.54 kg/ton Ag), trace gold, 4.0 percent (%) zinc, and 0.8% lead. Ore metal recoveries were good, presumably due to the coarse grain sizes of the contained argentite, native silver, silver-zinc sulfide minerals, and visible gold.

Engineering summaries and longitudinal sections dated January 15, 1907 and May 16, 1908 of this portion of the Republica Vein reported an average 12 foot (3.66 m) vein width on the 300 foot level that assayed an average of 175 ounces per ton silver (5.99 kg/tonne Ag) along a 111 foot (33.8 m) horizontal length of the north drift. This section indicates that the Republica vein thickened to that depth, from a vein width of 1.66 metres near the surface.

Local visible gold has been reported in the La Republica Mine, and veining at the surface appears to indicate 3 or 4 pulses of mineralization, with the high-grade silver event perhaps having been the last pulse. One early, brecciated phase of yellowish vein quartz looks similar to gold-mineralized vein quartz to the north at Mexivada's Yécora project. The property vendor reported that his two assay samples of the 5.5 foot (1.66 metre) wide vein on the 13 m level that he excavated in 1997, just north of the old mine workings, contained a) 497 g/tonne silver and b) 1 kg/ton silver and 1.0 g/ton gold in the latter sample.