These specimens are a classic from Las Herrerías mine, and they appeared many years ago. In this piece we can observe a cavity in the rock partially filled with silver foliaceous aggregates, kongsbergite variety, very brilliant and with a silver color with bronze reflections and bluish iridescence, characteristic for the species. This aesthetic and historical specimen has been analyzed and the result will be sent to the buyer. It belongs from the Rolando Gallina mineral collection (Italy).