Boulangerite or antimonbleiblende is an uncommon monoclinic orthorhombic sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11.

Nowadays it is considered as an uncommon mineral, which is rather cheap, with a color of light blue to black to grey.

The strong subcell is orthorhombic, and has a halved c.[3] It forms small, elongated prismic or fine, needle-like crystals.

One of its unique properties is the parallel fibers to the direction of the elongation, although fibrous-radial, feathery masses are not uncommon as well.

[4] The latter is the so-called plumosite variant of the mineral, the name derived from the aggregates being plumose, though it can occur in felt-like fibrous or in thick granular clusters as well.

It is also usually found with other sulfides as well, like with arsenopyrite, pyrrhotite, galena or sphalerite, but is also can occur with siderites, dolomites and quartzes.

Usual finding places include Germany, Switzerland, Canada, the Czech republic, the old Yugoslavia, the Ural region in Russia, and from the british park city mines in Utah.

[5] At first glance, it is hard to differentiate boulangerite from zinkenite or jamesonite, so proper equipment is crucial for the identification.