Silver mineralization of the deposit of Kanjol (Northern Tajikistan)

Abstract

The article gives information on the stages of mineralization and gives a description of some minerals from the Kanjol deposit.It is noted that the formation of minerals in the field occurred in 5 stages – quartz-arsenopyrite, polymetallic, copper-antimony, quartz-calcite with silver and carbonate. In the early quartzarsenopyrite stage, silver is found in very small quantities and ranges from 20 to 30 g/t. In the second polymetallic stage, silver is deposited together with galena and is in its crystal lattice as an isomorphic impurity. In galena, the average silver content is 4240 g/t. In the third copper-antimony stage, a silver-containing tetrahedrite is formed with a silver content of 5.7-20.20 wt.%. The concentration of silver in sulfides of this stage is (g/t): in galenites 2865, chalcopyrite 330 and pyrite 358,7. Then the most productive stage on silver is formed – quartz-calcite with silver. Here silver forms its own minerals – pyrargyrite, argentite, polybasite, native silver, matildite. Silver minerals are found in the form of monomineral veins, veinlets and inclusions. The carbonate stage with quartz, barite and ore minerals (galena, sphalerite) completes the process of mineral formation at the deposit. Here silver is found in small amounts in sulfides. In general, 2–4 stages of mineral formation are productive for silver. The main amount of silver (60-70%) is associated with the 3rd stage of mineralization. The article describes the silver minerals themselves – pyrargyrite, argentite, native silver, polybasite, myargyrite, sylvanite, argentoyarosite, arsenargentite, cerargyrite, matildite, as well as tetrahedrite and galena, bearing industrial concentration of silver. Matildite on the field is described for the first time.