Rambergite is a manganese sulfide mineral with formula .
It has been found in anoxic marine sediments, rich in organic matter of the Gotland Deep, Baltic Sea and also in skarn in the Garpenberg area, Dalarna, Sweden. It was named after the mineralogist, Hans Ramberg (1917–1998).http://webmineral.com/data/Rambergite.shtml Webmineral data
It is a member of the wurtzite group and is chemically related to hauerite.
References