Samsonite is a silver manganese antimony sulfosalt mineral with formula Ag<sub>4</sub>MnSb<sub>2</sub>S<sub>6</sub>. It crystallizes in the monoclinic crystal system with a typical slender radiating prismatic habit. It is metallic black to steel black with no cleavage and a brittle to conchoidal fracture. In thin fragments it appears reddish brown in transmitted light and also leaves a red streak. It is soft, Mohs hardness of 2.5, and has a specific gravity of 5.51.
It was first named in 1910 after an occurrence in the Samson Vein of the Sankt Andreasberg silver mines, Harz Mountains, Germany.