Sphaerobertrandite Pekov I V, Chukanov N V, Larsen A O, Merlino S, Pasero M, Pushcharovsky D Y, Ivaldi G, Zadov A E, Grishin V G, Asheim A, Tafto J, Chistyakova N I European Journal of Mineralogy 15 (2003) 157-166 Sphaerobertrandite, Be3SiO4(OH)2: new data, crystal structure and genesis _database_code_amcsd 0006960 5.082 4.640 17.696 90 106.13 90 P2_1/c atom x y z Uiso Be1 .290 .416 .1198 .006 Be2 .629 .089 .9604 .007 Be3 .110 .917 .2924 .006 Si .0274 .4195 .3755 .0073 O1 .023 .574 .1430 .008 O2 .045 .571 .2933 .008 O3 .228 .069 .0990 .001 O4 .697 .974 .0540 .008 OH5 .307 .575 .0413 .011 OH6 .557 .465 .1939 .013