AM_Wherryite Formula: Pb7 Cu2 S4 Si2 O26 Name: Wherryite Unit cell: 20.789 5.787 9.142 90.0 91.24 90.0 , V=1099.58 Space group: C12/M1 (12)

Cooper M A , Hawthorne F C , The Canadian Mineralogist , 32 (1994) p.373-380, The crystal structure of wherryite, Pb7Cu2(SO4)4(SiO4)2(OH)2, a mixed, sulfate-silicate with [M(TO4)2] chains