AM_Serandite_4 Formula: Mn2 Na Si3 O9 H Name: Serandite Unit cell: 7.683 6.889 6.747 90.53 94.12 102.75 , V=347.29 Space group: P-1 (2)

Takeuchi Y , Kudoh Y , Haga N , Zeitschrift fur Kristallographie , 138 (1973) p.313-336, The interpretation of partial Patterson functions and its application, to structure analyses of serandite Mn2NaHSi3O9 and banalsite BaNa2Al4Si4O16, Locality: Tanohata mine, Japan