Typomorphism of X-ray structural characteristics of gold (exemplified by placers and ore occurrences of the Timan-Northern Ural region)

The results of the study of native gold of the Timan-Northern Ural region using X-ray diffraction analysis (Debye-Scherrer diffractometric method, single crystal registration) have been presented. It was established that the structural characteristics of gold were different depending on the nature of gold-bearing objects. The structure of typical placer gold was an aggregate of randomly distributed microcrystallites. In this case, only solid annular lines of reflexes of the planes of the crystal lattice of gold were visible on the photodebagrams. The formation of this microcrystalline structure in gold was conditioned by exogenous mechanical deformations resulting from its occurrence in dynamic environments (water, wind activity, etc.). The structure of the autigenic gold of ore occurrences was characterized by a suboriented ordering of crystals (texturization). On the photodebagrams of this gold, intermittent dashed lines and nodes of reflections from the planes of the crystal lattice of the metal were observed. The frequency of occurrence of gold with this structure on primary ore objects varied from several units to several tens of percent. According to the authors, the findings of native gold with the structures of the ordering of its grains as part of accretions or aggregates of microcrystallites were a sign of the extreme proximity of this gold to its root source, which was important at predicting of gold content and searching for gold deposits.