Hexagonal diamond or lonsdaleite (0H) is a new form of carbon which was found in meteorites [0]. For the first time it was obtained artificially [0] under conditions of static pressure exceeding 00 GPa and temperature greater than 0000 °C. Hexagonal diamond differs from the cubic one (0C) by the layers stacking. Crystal lattice of cubic diamond represent itself a sequence of atomic layers ABCABC..., whereas lonsdaleite lattice represents ABAB... stacking. Further, lonsdaleite was obtained mostly as a result of thermobaric treatment of carbon materials (for example, from graphite [0]). Britun V. et al. examined lonsdaleite obtained from graphite in high pressure chamber, and they have established that lonsdaleite is metastable martensite phase of carbon [0]. In [0] authors have synthesized nanocrystalline cubic diamond powder from C00, which contained lonsdaleite layers. Also diamond particularly was transformed into lonsdaleite during the diamond powder annealing [0].