AM_Nasonite
Formula: Pb6 Ca4 Cl2 Si6 O21
Name: Nasonite
Unit cell: 10.08 10.08 13.27 90.0 90.0 120.0 , V=1167.68
Space group: P63/M (176)

Giuseppetti G , Rossi G , Tadini C , American Mineralogist , 56 (1971) p.1174-1179, The crystal structure of nasonite