Preliminary data on the microrelief and surface topography of thallium-bearing minerals and supergene gold samples from the Khokhoy deposit, Aldan Shield

The ores of the Khokhoy gold deposit host associated thallium mineralization, a strategically important critical element widely used in high-tech industries, including electronics, optics, and scientific research. Thallium can be recovered as a coproduct during ore processing. Here, we present the first experimental data on the microrelief of samples of rare thallium minerals (avicennite, Sb-avicennite, and amgaite) and supergene gold from the Khokhoy deposit using a scanning probe microscope (СММ-2000). More specifically, surface topography was characterized by atomic force microscopy (AFM), and for the first time, the roughness and granularity parameters of these mineral phases were quantified at the nanoscale. Our analysis revealed that all studied samples exhibit a hierarchical structure, with micron-sized grains composed of subgrains 190–220 nm in size. In addition, granulometric analysis yielded a stable median particle diameter of 80–85 nm, suggesting a colloidal origin for the mineral aggregates formed in the supergene zone. Consequently, the presence of gold and thallium in submicroscopic and nanoscale forms within the ores must be considered when developing extraction technologies for complex ores. Overall, these findings expand the current understanding of the typomorphism of gold and thallium minerals and the mechanisms governing their secondary alteration.

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