Classic, old-time material from the famous mines at Cavnic, Romania. The steel-gray Tetrahedrite crystals (to 9 mm) are highly lustrous and sharp, and rest on a layer of intergrown Sphalerite. The underlying matrix is composed of well-formed, 4 mm Quartz crystals. There are even clusters of small, sparkling, Pyrite pyritohedrons that accent the piece quite nicely. Ex. Isaac Walker and Reinhard Wuster before entering Kay's collection at #5110. Isaac Walker was a famous English collector from the early 1800's (1794-1853), and his handwritten label is included here. For more on him: https://mineralogicalrecord.com/labels.asp?colid=1856