AM_Protoanthophyllite Formula: Mg6.378 Fe.622 Si7.96 Al.048 O24 H2 Na.048 Name: Protoanthophyllite Unit cell: 9.3553 17.9308 5.3117 90.0 90.0 90.0 , V=891.03 Space group: PNMN (58)

Konishi H , Groy T L , Dodony I , Miyawaki R , Matsubara S , Buseck P R , American Mineralogist , 88 (2003) p.1718-1723, Crystal structure of protoanthophyllite: A new mineral from the Takese ultramafic, complex, Japan