Sugilite Armbruster T, Oberhansli R American Mineralogist 73 (1988) 595-600 Crystal chemistry of double-ring silicates: Structures of sugilite and brannockite Note: x-coordinate of Na has been corrected _database_code_amcsd 0001157 10.009 10.009 14.006 90 90 120 P6/mcc atom x y z occ U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) K 0 0 .25 .0164 .0164 .0196 .0082 0 0 Fe 1/3 2/3 .25 .83 .0047 .0047 .0046 .00235 0 0 Al 1/3 2/3 .25 .17 .0047 .0047 .0046 .00235 0 0 Li .5 .5 .25 .017 .017 .016 .011 0 0 Si .23633 .35620 .38678 .0066 .0071 .0057 .0036 .0005 .0006 O1 .1383 .3972 0 .019 .019 .0062 .0081 0 0 O2 .2232 .2774 .1377 .0130 .0155 .0161 .0104 .0005 .0007 O3 .1665 .5091 .17032 .0106 .0091 .0117 .0045 -.0013 -.0035 Na 1/3 2/3 .0134 .49 .0175 .0175 .026 .00875 0 0