These acanthite crystals are from the San Juan de Rayas Mine in Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico. This is a gold and silver mine that contains 16 different minerals including acanthite. It is a silver sulfide containing the elements Ag and S. This piece Is a floater with intact, well defined, crystals on all sides. There is no apparent point of attachment or traces of remnant matrix present. It displays nicely from any side or angle.The crystals have pseudo-cubic habits with some skeletal growth. They have a silver-grey color, stair step crystal faces, and a metallic luster. This is a thumbnail sized piece and it measures 20 x 20 x 13 mm.