Application of synchrotron radiation to the study of the internal structure of natural regular and irregular diamonds

The internal structure of regular and irregular diamond crystals of the Snap Lake deposit of the Slave province (Canada) is studied using the Laue-SR synchrotron method. The crystals under study were classified into regular and irregular diamonds according to IR spectroscopy data. It is shown that irregular diamonds, in contrast to regular, underwent plastic deformation during the postgrowth period. Plastic deformation by slip or spinel-law twinning is observed for diamonds with insignificant nitrogen concentrations. For most studied crystals with high concentrations of platelets (B' defects), irregular misorientations of local regions of a deformed crystal, such as faults and kinks, are characteristic. The interaction of dislocations formed during plastic deformation, with the dislocations surrounding the platelets, causes destruction of the latter at high P-T parameters typical of the upper mantle.