AM_Shafranovskite Formula: Na9 K5.7 Mn10.86 Si26.72 O87.72 H35.72 Name: Shafranovskite Unit cell: 14.519 14.519 21.062 90.0 90.0 120.0 , V=3845.06 Space group: P31C (159)

Krivovichev S V , Yakovenchuk V N , Armbruster T , Pakhomovsky Y A , Weber H-P , Depmeier W , American Mineralogist , 89 (2004) p.1816-1821, Synchrotron X-ray diffraction study of the structure of shafranovskite,, K2Na3(Mn,Fe,Na)4[Si9(O,OH)27].nH2O, a rare manganese silicate from Kola peninsula, Russia