Hermannjahnite is a rare sulfate mineral with the relatively simple formula CuZn(SO4)2. It is one of many fumarolic minerals discovered on the Tolbachik volcano.[2][3]
Relation to other minerals
Hermannjahnite is a zinc-analogue of dravertite – another mineral from prolific Tolbachik.[4] Minerals somewhat chemically similar to hermannjahnite include ktenasite and christelite.[5][6]