AM_Brianroulstonite Formula: Ca3 Cl2 B5 O21 H23 Name: Brianroulstonite Unit cell: 17.367 8.079 8.693 90.0 121.56 90.0 , V=1039.30 Space group: P1A1 (7)

Grice J D , Gault R A , Van Velthuizen J , The Canadian Mineralogist , 35 (1997) p.751-758, Brianroulstonite: A new borate mineral with a sheet structure