AM_Bertrandite_3 Formula: Be4 Si2 O9 H2 Name: Bertrandite Unit cell: 8.587 14.912 4.5901 90.0 90.0 90.0 , V=587.76 Space group: CMC21 (36)

Hazen R M , Au A Y , Physics and Chemistry of Minerals , 13 (1986) p.69-78, High-pressure crystal chemistry of phenakite (Be2SiO4), and bertrandite (Be4Si2O7(OH)2), Sample: P = 41 kbar, Note: y-coordinate of O3 altered