Boulangerite

Boulangerite is a sulfosalt mineral, lead antimony sulfide, formula Pb₅Sb₄S₁₁. It was named in 1837 honor of French mining engineer Charles Boulanger. It forms metallic grey monoclinic crystals.[1][2] Sometimes the crystals form a fine feathery mass which has been called plumosite.

References

1. ^ http://webmineral.com/data/Boulangerite.shtml Webmineral data
2. ^ http://www.mindat.org/min-738.html Mindat

List of minerals