AM_Mg8(Mg2Al2)Al8Si12(O,OH)56 Formula: Mg4.76 Al5.01 Si6 O28 Name: Mg8(Mg2Al2)Al8Si12(O,OH)56 Unit cell: 8.5758 5.7295 18.5376 90.0 97.691 90.0 , V=902.65 Space group: P121/M1 (11)

Artioli G , Fumagalli P , Poli S , American Mineralogist , 84 (1999) p.1906-1914, The crystal structure of Mg8(Mg2Al2)Al8Si12(O,OH)56 pumpellyite and its, relevance in ultramafic systems at high pressure