AM_Alunite
Formula: K S2 Al3 O14 H6
Name: Alunite
Unit cell: 6.96 6.96 17.35 90.0 90.0 120.0 , V=727.86
Space group: R-3M (166)

Hendricks S B , American Mineralogist , 22 (1937) p.773-784, The crystal structures of alunite and the jarosites