A peculiar Bolivian sulfide/sulfosalt pseudomorph! This curious small cabinet piece features a myriad of knobby, stacked, malformed clusters of what were stephanite crystals are now almost completely replaced by dark gray, sooty acanthite. This really is a unique specimen from the silver mines in Bolivia and an interesting pseudomorph. Ex. Dr. Werner Paar collection with label that indicates the presence of polybasite, argyrodite, greenockite(?), and galena.