An old classic chalcocite from one of the most famous copper mines in Africa, one from which few copper-rich specimens survived. Well crystallized, this specimen is highlighted by intergrown drill-bit twins, many to 1 cm. The color varies from dark gray to brownish gray and the crystals exhibit some luster with this natural patina variation. This is a superb, sharp miniature of chalcocite from a highly desirable locality, and in pristine condition, complete 360 degrees around, except only 2 tiny dings on back. From an old European collection.