Diamond-lonsdaleite-graphite micro-samples collected from peat after the 1908 catastrophic blast in the Tunguska area were studied with scanning (SEM) and transmission electron (TEM) microscopy, NanoSecondary Ion Mass Spectrometry (NanoSIMS) and Х-ray synchrotron technique. The high-pressure carbon allotropes in the Tunguska samples are being described for the first time Attributing this fact to the primary inhomogeneity, and considering the microstructural features such as cracks, deformation of the crystal lattices, etc coupled with high-pressure carbon allotropes association with metals, sulfides and phosphides, and the high ratio of Fe:Ni = 22:1 suggest that the studied samples are meteorite micro-remnants.

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internal morphologies of natural impact apographitic diamonds (paramorphoses) have been studied. The (0001) surface morphology of the paramorphoses reflects their phase composition and the structural relationship of their constituting phases. Growth and etch figures together with the elements of crystal symmetry of lonsdaleite and diamond are developed on these surfaces. The crystal size of lonsdaleite is up to 100 nm, and that of diamond is up to 300 nm. Two types of structural relations between graphite, lonsdaleite, and diamond in the paramorphoses are observed: the first type (black, black-gray, colorless and yellowish paramorphoses)-(0001) graphite is parallel to (10 10) lonsdaleite and parallel to (111) diamond; the second type (milky-white paramorphoses)-(0001) graphite is parallel to (10 10) lonsdaleite and parallel to (112) diamond. The first type of the paramorphoses contains lonsdaleite-diamond-graphite or diamond-lonsdaleite, the second type of the paramorphoses contains predominantly diamond. The direct phase transition of graphite → lonsdaleite and/or graphite → diamond occurred in the paramorphoses of the first type. A successive phase transition graphite → lonsdaleite → diamond was observed in the paramorphoses of the second type. The structure of the paramorphoses of this type shows characteristic features of recrystallization.

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