Classic Cornish Cogwheel Ore specimen from the Herodsfoot Mine, Lanreath. Excellent repeat twinned crystals of dark metallic grey Bournonite are intergrown and scattered over a sparkling druse of Quartz. A crystal druse of Quartz also having partly to completely enveloped tan crystals of Siderite, with areas of iridescent yellow Chalcopyrite. Fine small cabinet Bounonite from this famous mine.