AM_Offretite Formula: (Si12.78 Al5.22) Ca1.4 K Mg O49.52 H25.678 Name: Offretite Unit cell: 13.293 13.293 7.608 90.0 90.0 120.0 , V=1164.25 Space group: P-6M2 (187)

Gualtieri A , Artioli G , Passaglia E , Bigi S , Viani A , Hanson J C , American Mineralogist , 83 (1998) p.590-606, Crystal structure-crystal chemistry relationships in the zeolites erionite, and offretite, Sample from Mt. Semiol