Consummate classic metallic yellow Chalcopyrite coated Tetrahedrite crystal specimen, from the Herodsfoot Mine, Lanreath, Cornwall. Well developed tetrahedral crystals of Tetrahderite measuring to 1.2cm on edge are abundantly inter grown, on the characteristic crystallized white Quartz matrix. In close association with the Tetrahedrite are inter grown metallic lead grey crystals of Galena. A super specimen from the mine.