Abstract. An analysis of electron transmission and scanning micrographs of various types of dust deposit in tokamak T-10 is carried out for (a) analyzing the origin of non-trivial (e.g. cauliflower-like) structures in dust deposits, and (b) verifying the former hypothesis for possibility of self-assembling, during electric breakdown, of skeletal macrostructures from wildly formed carbon nanotubes. The results (Phys. Lett. A, 269 (2000) 363; 291 (2001) 447) show (i) presence of tubular structures in the range of diameters D 5 nm - 10 microns; (ii) trend of assembling bigger tubules from smaller ones (i.e., the self-similarity); (iii) ability of nanotubular structures to build up the skeletons of various topology, including the tubules, cartwheels, dendrites; (iv) presence of an amorphous component which may hide the internal skeleton either fully (to give a solitary dust particle) or partly (to give an agglomerate of visually separate particles); (v) similarity of structures in dust deposits, in the range D < 10 microns, and in the images taken during electric breakdown in various types of discharge (tokamak, plasma focus, Z-pinch), D 100 microns - 10 cm.