The first data about iodine and bromine mineralization in the black shales of the Far East <i>.</i>
Microaggregates of subnanocrystals of iodargirite – AgI and iodobromite – Ag (I, Br) with native silver, acantite – Ag <sub>2</sub>S, cerargyrite – AgCl were detected by scanning electronic microscope. This mineral assemblage indicates crystallization of silver halides from hydrothermal fluid. Besides, Br admixture up to 3.2 at.% was measured in pyrite, arsenopyrite, scorodite and native silver. Br admixture in ore minerals excepts isomorphic substitution and accounts for an endocryptic process (after V.L.Tauson). Analysis of I and Br content in metamorphic rocks allows evaluating sedimentary or magmatic genesis of a protolite owing to the well-defined tendency of I and Br to accumulate in marine sediments.