A sparkling metallic silvery-grey druse of Tennanite micro-crystals cover the botryoidal surface of Chalcopyrite variety Blister Copper Ore from the classic Cornish Tennantite location of Wheal Jewel, St. Day. The Blister Copper Ore has formed on a matrix of mixed white Quartz-Chalcopyrite and minor Bornite. The specimen comes with an old Arthur Kusche of Munich label circa 1920.