Features of production and study of the process of silver alloy complex liquation on the example of Imperial rubles of 1899

The materials presented in the article are aimed at supplementing and clarifying the historical patterns of the domestic coinage development, including establishing the characteristics of the composition and structure of the original silver coins, which allows usage of these indicators to confirm the authenticity of silver products of the late XIX – early XX centuries. In this case, methods of historical and scientific analysis were used, as well as modern physico-chemical methods of scanning electron microscopy with secondary electron and scattered electron detectors and the method of energy dispersion spectrometry. It is shown that silver coins were produced at the Saint Petersburg Mint for a long historical period as a measure of the financial market stabilization, reflecting the general patterns of European coin production. At the same time, the shortage of Russia's own sources of silver was covered by the re-minting of foreign coins with the release of domestic silver rubles based on an alloy with fineness 900 copper containing impurities of lead, zinc, sulfur, etc. It is these impurities and their distribution in the silver matrix that are characteristic markers of the authenticity of silver products. The role of the mintmasters in observing the quality control of production and final products at the Mint has been established. The receipt of the same type of products was not guaranteed; the product was certified by the personal mark of the mintmaster on the reverse and/or obverse of the coin, which was a sign of quality compliance. It has been experimentally established that the technologies of melting silver alloys and minting coins of the late XIX – early XX centuries allowed for a noticeable and determined by modern instrument methods liquation of impurity elements in the silver matrix, which reflects the technological stages of coin production and is a characteristic feature of silver coins. This makes it possible to use the considered feature to identify the authenticity of the relevant products. The research was conducted within the framework of the scientific direction “Historical and cultural heritage of Russia and the development of scientific knowledge” of the Saint Petersburg Mining University.