Harrisonite Grice J D, Roberts A C The Canadian Mineralogist 31 (1993) 781-785 Harrisonite, a well-ordered silico-phosphate with a layered crystal structure. Ca(Fe,Mg)6(SiO4)2(PO4)2 Locality: Arcedeckne Island, Artic Canada _database_code_amcsd 0005340 6.248 6.248 26.802 90 90 120 R-3m atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Ca 0 0 0 .0113 .0066 .0066 .0206 .0033 0 0 Fe .4969 .9938 .0950 .88 .0078 .0065 .0070 .0101 .0035 .0001 -.0002 Mg .4969 .9938 .0950 .12 .0078 .0065 .0070 .0101 .0035 .0001 -.0002 Si 0 0 .8623 .0058 .0056 .0056 .0062 .0028 0 0 P 0 0 .6802 .0062 .0066 .0066 .0054 .0033 0 0 O1 0 0 .1988 .009 .009 .009 .007 .0048 0 0 O2 0 0 .6224 .008 .009 .009 .008 .0043 0 0 O3 .1429 .2858 .1183 .0092 .008 .012 .012 .0038 .0011 .002 O4 .7979 .5958 .0362 .0104 .013 .008 .008 .0043 .0002 -.0000