Polyakovite-(Ce) Popov V A, Pautov L A, Sokolova E V, Hawthorne F C, McCammon C A, Bazhenova L F The Canadian Mineralogist 39 (2001) 1095-1104 Polyakovite-(Ce), (REE,Ca)4(Mg,Fe)(Cr,Fe)2(Ti,Nb)2Si4O22, a new metamict mineral species from the Ilmen Mountains, Southern Urals, Russia: Mineral discription and crystal chemistry Locality: Ilmen Mountains, Southern Urals, Russia _database_code_amcsd 0005725 13.398 5.6974 11.042 90 100.539 90 C2/m atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) CeA1 .35606 0 .73540 .46 .0152 .0122 .0194 .0139 0 .0020 0 LaA1 .35606 0 .73540 .31 .0152 .0122 .0194 .0139 0 .0020 0 NdA1 .35606 0 .73540 .09 .0152 .0122 .0194 .0139 0 .0020 0 PrA1 .35606 0 .73540 .04 .0152 .0122 .0194 .0139 0 .0020 0 YA1 .35606 0 .73540 .01 .0152 .0122 .0194 .0139 0 .0020 0 CaA1 .35606 0 .73540 .06 .0152 .0122 .0194 .0139 0 .0020 0 ThA1 .35606 0 .73540 .03 .0152 .0122 .0194 .0139 0 .0020 0 CeA2 .07041 0 .74116 .46 .0199 .0122 .0338 .0136 0 .0018 0 LaA2 .07041 0 .74116 .31 .0199 .0122 .0338 .0136 0 .0018 0 NdA2 .07041 0 .74116 .09 .0199 .0122 .0338 .0136 0 .0018 0 PrA2 .07041 0 .74116 .04 .0199 .0122 .0338 .0136 0 .0018 0 YA1 .07041 0 .74116 .01 .0199 .0122 .0338 .0136 0 .0018 0 CaA2 .07041 0 .74116 .06 .0199 .0122 .0338 .0136 0 .0018 0 ThA2 .07041 0 .74116 .03 .0199 .0122 .0338 .0136 0 .0018 0 Mg1 1/2 0 1/2 .80 .0169 .0200 .0143 .0161 0 .0022 0 Fe1 1/2 0 1/2 .20 .0169 .0200 .0143 .0161 0 .0022 0 Ti2 1/4 1/4 0 .76 .0093 .0113 .0101 .0061 .0002 .0003 .0002 Nb2 1/4 1/4 0 .16 .0093 .0113 .0101 .0061 .0002 .0003 .0002 Cr3 0 0 0 .64 .0120 .0135 .0156 .0067 0 .0017 0 Fe3 0 0 0 .36 .0120 .0135 .0156 .0067 0 .0017 0 Cr4 1/2 0 0 .64 .0133 .0150 .0169 .0071 0 -.0003 0 Fe4 1/2 0 0 .36 .0133 .0150 .0169 .0071 0 -.0003 0 Si(1) .2022 -1/2 .7327 .0105 .0180 .0076 .0054 0 .0009 0 Si(2) .3582 -1/2 .5452 .0123 .0128 .0135 .0103 0 .0017 0 O(1) .4785 .252 .8726 .0108 .0114 .0107 .0097 -.0005 .0004 .0005 O(2) .1472 0 .9782 .0109 .0138 .0090 .0107 0 .0042 0 O(3) .1888 0 .5982 .0146 .0193 .0189 .0046 0 -.0004 0 O(4) .3495 0 .9887 .0090 .0076 .0084 .0094 0 -.0026 0 O(5) .4283 .2689 .5915 .0254 .0340 .0247 .0159 .0120 .0003 .0021 O(6) .2279 -.736 .8147 .0132 .0220 .0109 .0060 .0028 .0010 -.0003 O(7) .0869 -1/2 .669 .0302 .0201 .0576 .0117 0 -.0005 0 O(8) .2750 -1/2 .632 .0354 .0345 .0619 .0151 0 .0185 0