The invention is for an ultrahard composite material comprising a diamond phase and a binder phase, the binder phase comprising a ternary carbide of the general formula Mx M'y C wherein; M is at least one metal selected from the group consisting of the transition metals and the rare earth metals, M' is a metal selected from the group consisting of the main group metals or metalloid elements and the transition metals Zn and Cd, x is from 2.5 to 5.0, y is from 0.5 to 3.0 and z is from 0.1 to 1. The invention extends to a diamond abrasive compact comprising such an ultrahard composite material and to a tool comprising such a diamond abrasive compact.