AM_Montgomeryite Formula: Ca2 Mg.5 Al2 P3 O20 H14 Name: Montgomeryite Unit cell: 10.023 24.121 6.243 90.0 91.55 90.0 , V=1508.79 Space group: C12/C1 (15)

Moore P B , Araki T , American Mineralogist , 59 (1974) p.843-850, Montgomeryite, Ca4Mg(H2O)12[Al4(OH)4(PO4)6]:. Its crystal structure and, relation to Vauxite, Fe2(H2O)4[Al4(OH)4(H2O)4(PO4)4].4H2O