ACANTHITE (ARGENTITE)

A vuggy mass of intergrown, crude, metallic silvery-black Acanthite crystals on a thin granular matrix of sandy-tan quartz.  Acanthite is the low-temperature paramorph of the silver sulphide Argentite; at ambient room temperature, only Acanthite can exist.  By convention, the crude crystals resembling Argentite in this specimen may be more properly named “Acanthite after the octahedral high-temperature phase Argentite”, although this may require a longer label!  This is a great specimen from Schlema in Erzgebirge, Saxony, Germany.