AM_Bassanite Formula: Ca2 S2 O9 H2 Name: Bassanite Unit cell: 12.035 6.9294 12.6705 90.0 90.266 90.0 , V=1056.65 Space group: I121 (5)

Ballirano P , Maras A , Meloni S , Caminiti R , European Journal of Mineralogy , 13 (2001) p.985-993, The monoclinic I2 structure of bassanite, calcium sulphate hemihydrate