Bournonite is a sulfo-antimonite of lead and copper (PbCuSbS3). The crystal system is orthorhombic and crystals display a short prismatic to tabular habit, the fringes are often coarsely striated. It is a mineral formed in medium temperature hydrothermal veins, often associated with other metalliferous minerals. This specimen is from Neudorf in the Harz area of southern Germany. Actual width of sample is 120 mm.