Plate impact experiments have been performed on the igneous diamond‐bearing matrix kimberlite. Longitudinal and lateral stresses were measured in the uniaxial strain regime using manganin stress gauges. The shock Hugoniot of the kimberlite has been characterized at axial stresses between 1 and 9 GPa. The kimberlite has a low impedance response when compared with similar data for other geological materials. The data indicate that the rock behaves inelastically above shock stresses of 1 GPa. © 2004 American Institute of Physics