This is a section of a “Rogue Vein” (an isolated inexplicable metal occurrence) that consists of collected from an Eastern Ontario. Boulangerite is a sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11. It was named in 1837 in honor of French mining engineer Charles Boulanger (1810–1849). It forms metallic grey monoclinic crystals. Sometimes the crystals form a fine feathery mass which has been called plumosite. Boulangerite is occasionally used as a lead ore.
This is one measures 3.5″ by 2.75″ by 0.75″ and weighs in at nine ounces, so shipping for should be $12.50 for locals within North America.