A very large, lustrous cogwheel type Bournonite (over 5 CM across) that is complete sitting on Fluorite and Quartz crystals one of which penetrates the Bournonite. A exceptional example from Yaogangxian, recognized as the worlds best location for this specie. Some of the fluorite and quartz have damage especially at the edges of the piece, but overall the condition is superb. This sits upright and perfectly without assistance, and the esthetics are top shelf. Given the fragility of large bournonite, the quality and completeness of this crystal is even more remarkable. Add the Fluorite for a color accent (and an uncommon association) the whole is highly desirable.