Spheroidal formations of ore and non-metallic matter in nature and experiment

Research subject . Spheroidal formations from technogenic placers, paleoplacers, and granitoids of the Nizhneselemdzhinsky gold-bearing node; from the placer of the Urkimi gold-bearing node; spheroidal nano-sized gold of the Oktyabrsky gold-bearing node; gold balls resulted from experiments on the concentration and consolidation of precious metals; as well as metallosilicate spheroids from the gastrointestinal tract of the flat sea urchin. Methods. Spheroids were studied by raster electron microscopy; their composition was determined using atomic absorption spectrometry. Results. The mor phology and chemical composition of spheroids were studied. The following types were established: metal spheroids – gold, lead, iron, spheroids consisting of Fe-based alloys; metal-alloyed (Sb); metal oxides (Fe, O) and (Cu, O); silicates (Si, O) and metalolylic (Ag and others, Si, О). Depending on the environment in which the studied spheroids were formed, different factors determined the formation of round forms of mineral matter, including the following. (1) Gas metamorphism – natural hydrothermal-metallurgical process leading to the formation of spherical forms of minerals. (2) Cluster formation of aggregated (polycrystalline) balls under conditions of an unbalanced process of self-organization of particles of matter. (3) Geochemical barriers that became the centers of origin of spheroid nanoparticles. (4) Secondary processes affecting the surface layer of the spheroid particles after the formation of their main composition: (a) hypergenesis leading to the destruction of some and formation of other minerals and (b) mechanical processing of hard materials in the splits. (5) Non-equilibrium biogenesis (for bio-organisms).