the basis of the mineral composition (Fe0.873±0.02S – Fe0.885±0.02S) and parageneses.The Fe0.873÷0.875S compositions close to Fe7S8 (Apy+Po+Rut+Qz), for which the estimated range of formation parameters is 486–465°С and log fS2-4.71 to -5.28, are typical for early pyrrhotite associated with rutile and quartz, in the form of …