In Western Sayan, researchers from the Tuva Institute and the Siberian Federal university made a sensational discovery. They found authigenic gold – a rare type of metal that is formed not in the depths of the Earth, but directly in river sediments.
Discovered gold has bizarre shapes: scales, hair-like growths and tangled fibrous structures. Scientists suggest that bacteria and electrochemical processes occurring in the waters of gold-bearing formations are involved in its formation. The results of the study were published in the journal Geosphere Research.
Of particular interest are technogenic varieties of the metal that appeared due to the use of mercury in mining. Traces of gold-silver amalgam were found in the dumps, which proves that even years after the development of deposits, gold continues to change.
Using electron microscopy, it was established that authigenic gold has a high fineness – from 937 to 1000 ‰. It is formed on the surface of already enriched metal particles due to the activity of gold-phile bacteria capable of precipitating gold from water.
Although the share of such gold in placers does not exceed tenths of a percent, its study is important for understanding the behavior of the metal in nature. This discovery may help in the search for new deposits and improving extraction methods.
The research was supported by the electron microscopy laboratory of the Norilsk Nickel R&D center. Scientists intend to continue working to uncover all the secrets of the formation of authigenic gold. Their discovery can revolutionize ideas about the origin of precious metals.
The material was prepared with the support of the Russian Ministry of Education and Science as part of the Decade of Science and Technology.
Source: @zolteh
