Ribbeite Freed R L, Rouse R C, Peacor D R American Mineralogist 78 (1993) 190-194 Ribbeite, a second example of edge-sharing silicate tetrahedra in the leucophoenicite group _database_code_amcsd 0001545 10.732 15.672 4.811 90 90 90 Pnma atom x y z occ Biso Mn1 .86850 .14501 .49334 1.11 Mn2 .59124 .25 .51449 1.11 Mn3 .64402 .06127 -.00408 1.24 Si1 .7779 .25 .0712 0.55 Si2 .4613 .0448 .5835 .5 0.65 O1 .4616 .0432 .2672 1.22 O2 .7778 .25 .7381 0.73 O3 .9179 .25 .2125 0.78 O4 .7101 .1681 .2123 0.75 O5 .5286 .1373 .7311 1.58 O6 .3109 .0439 .7344 1.37 H1 .555 .126 .569 .5 1.7 H2 .345 .034 .600 .5 2.0