This bournonite is from the Yaogangxian Mine, Xaogangxian W-Sn Ore Field, Tizhang, Chenzhou Prefecture, Hunan Province of China. Tungsten and tin are the primary minerals extracted from multiple ore bodies in an area spanning 4 x 2.5 km. Seventy-eight different species of minerals are found there Including bornonite. It is a lead sulfide that contains the elements Pb, Cu, Sb and S. This specimen is a cluster of complex bournonite crystals. They have a silver grey color and a sub-metallic luster with a faint iridescence on some surfaces. This piece measures 20 x 19 x 14 mm.