An uncommon well formed specimen of Pearceite, a Silver Copper Sulfosalt, from the San Juan de Rayas Mine, Mexico. Crystals of lustrous metallic grey Pearceite are tabular hexagonal in form in a platy stacked-like habit, measuring to 1cm +. The crystals of Pearceite stand upright on edge from the matrix of metallic yellow Chalcopyrite coated 'Pearceite/Polybasite'. A fine small cabinet specimen of this uncommon species, from a mine reputed to have been discovered in the mid-17th century.