Londonite Gatta G D, Vignola P, McIntyre G J, Diella V American Mineralogist 95 (2010) 1467-1472 On the crystal chemistry of londonite [(Cs,K,Rb)Al4Be5B11O28]: a single-crystal neutron diffraction study at 300 and 20 K Locality: Antsongombato Gem mine, Betafo district, Madagascar Note: neutron diffraction study at T = 300 K _database_code_amcsd 0017717 7.3098 7.3098 7.3098 90 90 90 P-43m atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Cs 0 0 0 .34 .023 K 0 0 0 .34 .023 Rb 0 0 0 .17 .023 Al .3608 .3608 .3608 .0020 .0020 .0020 .0020 -.0001 -.0001 -.0001 Be1 .24835 .5 0 .12 .0028 .0031 .0030 .0022 0 0 -.0002 B1 .24835 .5 0 .88 .0028 .0031 .0030 .0022 0 0 -.0002 Be2 .25833 .74167 .25833 .97 .0036 .0036 .0036 .0036 .0001 -.0001 .0001 B2 .25833 .74167 .25833 .03 .0036 .0036 .0036 .0036 .0001 -.0001 .0001 O1 .38103 .61897 .38103 .0023 .0023 .0023 .0023 .0003 -.0003 .0003 O2 .36350 .36350 .09976 .0039 .0045 .0045 .0027 .0007 .0003 .0003 O3 .39923 .86485 .13515 .0040 .0046 .0037 .0037 -.0004 .0004 .0001