The deformation tracks distribution in a single crystal of the high melting FCC-metal iridium, which exhibits the cleavage after considerable elongation, is considered. The octahedral slip is the sole deformation mechanism in iridium single crystal at room temperature, and, therefore, its mechanical behavior is similar to the behavior of a FCC-metal. However, in contrast to other FCC-metals, the resource of plasticity of the iridium single crystalline samples is exhausted at the initial/early stages of plastic deformation, when the octahedral slip bands are homogeneously distributed on the working surface and the necking is absent in vicinity of the dangerous crack.