The acanthite crystals from this mine located near Guanajuato, Mexico, are world-renowned. The specimens we occasionally find for sale are usually aggregates of cubic-shaped crystals. This specimen we offer stands out for its centimeter-sized, highly defined crystal, with the usual cube faces truncated by the octahedron. The metallic luster is very good and it is arranged airily on a matrix formed by small, hyaline quartz crystals. An exceptional and ancient piece...