Falkmanite is a mineral closely related to Boulangerite but with less lead. Mindat reports that: "A solution of the crystal structure of falkmanite is necessary for its definite classification." The XRD patterns of boulangerite and falkmanite are similar. Indeed some textbooks equate it to Boulangerite. Most recent Hrysl's "Minerals and their Localities" it is listed as a unique mineral.
This specimen's splendid habit is a metallic compact fibrous mass with a beautiful silky finish.