Abstract: This study introduces a new type of manganese occurrence in Turkey. The occurrence is located near Zilan (Erciş, Van), associated with pumice tuffs cropping out in the region, and fills the spaces between thegalssy clasts in pumice tuff. It has a mono-mineralic composition containing 65-73 % MnO, 3-5.5 % K2O, 2.5-4 % BaO, 0.5-1 % SrO, 0.5-1 % CaO and 0.3-0.7 % Na2O. Accordingto such a chemical composition the mineral has been calculated to have a formulae of(Na, K, Ca, Ba, Sr, Mn+^)2 MngOjgxH2O.Such a composition is similar to but contains more Mn than romanecite. Zilan Mn occurence has a hydrogenetic-detrital origin based on the Al-Si diagram. Mg-Na plot indicates afresh water environment for its origin. These in turn suggets that manganese was dissolved by surficial waters from the basic to intermediate volcanicsin the region, transported as Mri*`"" or in the from of organo-metallic complexes, deposited within the pumice tuffs which provided alkaline-oxidising conditions.