A powder mixture of copper and graphite was dynamically shock‐compressed by a rod‐in‐cylinder method. Structural characterization of the recovered specimen by transmission electron microscopy (TEM) showed the development of fine spherical diamond particles through shock‐induced nuclei formation in the high pressure state and shock‐assisted nuclei growth during unloading to ambient pressure via a solid–liquid–solid (SLS) phase transformation. A 2 &mgr;m large diamond particle was formed via a shock‐induced martensitic path. Quantitative numerical simulation applying the two‐dimensional computation code AUTODYN 2D was conducted to evaluate the pressure conditions during shock loading. ©1995 American Institute of Physics.