AM_Howlite_1
Formula: Ca2 Si B5 O14 H5
Name: Howlite
Unit cell: 12.82 9.351 8.608 90.0 104.84 90.0 , V=997.51
Space group: P121/C1 (14)

Griffen D T , American Mineralogist , 73 (1988) p.1138-1144, Howlite, Ca2SiB5O9(OH)5: Structure refinement and hydrogen bonding