AM_Hennomartinite Formula: Sr Mn2 Si2 O10 H8 Name: Hennomartinite Unit cell: 6.247 9.034 13.401 90.0 90.0 90.0 , V=756.29 Space group: P21CN (33)

Libowitzky E , Armbruster T , American Mineralogist , 81 (1996) p.9-18, Lawsonite-type phase transitions in hennomartinite, SrMn2[Si2O7](OH)2.H2O, T = 22 C