An exceptional, stout, brilliant metallic crystal of bournonite from the famed Yaogangxian polymetallic deposit in China. This exceptional large, single crystal exhibits a combination of both almost mirror bright and striated prism faces along with dominant pinacoid and tiny pyramid faces that display subtle growth hillocks adding to its reflectivity. Another great attribute is that while looking at the top of the crystal (down the c-axis) it's apparent that it is a cogwheel twin! An impressive example of this copper-lead-antimony sulfosalt. It is huge and heavy, and seems a bargain for the price because if it were complete on the back, you could 5X the value. But alas, it has only a frontal display view and so it looks amazing on a shelf but should be valued less, as the back is broken. Contacting and local uneven fracture on the bottom and backside detract from value, but not from impact visually as an important example of large size. Before the big China finds, if this were from England it would have been among the best known, but China redefined your expectations on this species. Still, the heyday is probably over and this is the only location there that produced them. Sits perfectly for display in a custom engraved acrylic base. 460 grams, or about a pound in weight!