Unusual topological features related to the interface Dirac electrons [1, 2] have been revealed: the longitudinal Hall quasi-plateaus, along with minima in magnetoresistance; the manifestation of Umkehr effect, non- allowed by the crystal symmetry; two new harmonics of quantum transport from interface layers, which characterizes larger than cross-sectional areas of the FS of crystallites; the magnetoresistance peculiarities, indicating both the occurrence of a small group of the infinitely moving electrons and the electronic phase transitions of the semiconductor–semimetal type in magnetic field. A high-field behaviour of αii(B) has been identified (it linearly increases in magnetic field without saturation, the sign changes from negative to positive, the nontrivial π-Berry phase is observed, etc.) in CIs layers, specifying the signature of 3D topological semimetal at 3D Dirac point forming (x ~ 0.04). In addition, it has been found that the bicrystals of Bi1-xSbx (0.07 ≤ x ≤ 0.2) alloys exhibit peculiarities typical of 3D TI: αii(B) undergoes saturation in magnetic field or smoothly increase, the Landau level index n in all CIs layers linearly depend on 1/Bn and extrapolated to –0.5 if 1/Bn → 0.