AM_Garrelsite Formula: Na Ba3 Si2 B7 O20 H4 Name: Garrelsite Unit cell: 14.639 8.466 13.438 90.0 114.21 90.0 , V=1518.95 Space group: C12/C1 (15)

Ghose S , Wan C , Ulbrich H H , Acta Crystallographica, Section B , 32 (1976) p.824-832, Structural chemistry of borosilicates. I. Garrelsite, NaBa3Si2B7O16(OH)4, a, silicoborate with the pentaborate [B5O12]9- polyanion, Locality: South Ouray, Utah