Internal structure of some diamond polycrystals from the Botuobinskaya tube

The article presents the results of study of four polycrystals of diamond with a zonal structure from the Botuobinskaya tube. Plates about 0.4 mm in thickness were cut out from the crystals. The registration of the absorption spectra in the IR range was carried out by a Bruker VERTEX-70 Fourier spectrometer with a Hyperion1000 microscope. In addition to the concentration of defects A and B1, the absorption coefficient in the B2 band, the position of its maximum, and the absorption coefficient in the 3107 cm-1 band were determined. Three types of low-temperature and polycrystalline shells were distinguished in accordance with its structural features. The shell of the first type consisted of oriented microblocks, contained a large number of carbonate and sulfide inclusions. The shell of the second type had a uniform structure with less inclusions. The transparent shell of the third type consisted of lamellas with a tangential growth mechanism, the space between them was filled with a diamond without clear structural features.