AM_Hilgardite-3A Formula: Ca2 Cl B5 O10 H2 Name: Hilgardite-3A Unit cell: 17.495 6.487 6.313 60.77 79.56 83.96 , V=614.77 Space group: P1 (1)

Wan C , Ghose S , American Mineralogist , 68 (1983) p.604-613, Parahilgardite, Ca6[B5O9]3Cl3*3H2O: a triclinic piezoelectric, zeolite-type pentaborate