Viboras Mine, Machacamarca, Machacamarca District (Colavi District), Cornelio Saavedra Province, Potosí Department, Bolivia
Matrix specimens of Bournonite from Machacamarca are hard to find, especially in the small cabinet to cabinet size range. Crude mining methods combined with brittle nature of the Bournonites (and sometimes their host rock) do not allow many crystals to leave the mine on matrix. This piece features a nice, sharp, lustrous, "chisel"-shaped crystal Bournonite on bladed Siderite matrix with minor micro Pyrite. The quality of the crystal itself is actually very good, and certainly worthwhile for somebody looking to purchase a nice Bournonite crystal on matrix. Better in person !