Cuspidine Bellezza M, Merlino S, Perchiazzi N European Journal of Mineralogy 16 (2004) 957-969 Chemical and structural study of the Zr,Ti-disilicates in the venanzite from Pian di Celle, Umbria, Italy Locality: Pian di Celle, Umbria, Italy _database_code_amcsd 0007083 10.919 10.485 7.485 90 109.55 90 P2_1/a atom x y z occ Uiso Ca1 .3125 .0879 .0290 .86 .016 Zr1 .3125 .0879 .0290 .14 .016 Ca2 .4198 .3682 .8399 .016 Ca3 .3061 .0950 .5307 .016 Ca4 .4235 .3684 .3310 .83 .015 Na4 .4235 .3684 .3310 .17 .015 Si1 .6309 .1893 .2260 .014 Si2 .6226 .1874 .6545 .013 O1 .6221 .2197 .4376 .038 O2 .7525 .2781 .2303 .021 O3 .7421 .2748 .7783 .024 O4 .6687 .0430 .2104 .028 O5 .6556 .0403 .7042 .033 O6 .4906 .2344 .0921 .023 O7 .4801 .2355 .6412 .021 F1 .6049 .4962 .9292 .019 F2 .3955 .4985 .5744 .020