Helmutwinklerite Krause W, Belendorff K, Bernhardt H J, McCammon C A, Effenberger H, Mikenda W European Journal of Mineralogy 10 (1998) 179-206 Crystal chemistry of the tsumcorite-group minerals. New data on ferrilotharmeyerite, tsumcorite, thometzekite, mounanaite, helmutwinklerite, and a redefinition of gartrellite Locality: Tsumeb mine, Namibia _database_code_amcsd 0006712 5.606 5.610 7.617 70.19 69.91 69.18 P-1 atom x y z Biso PbMe1 0 0 0 2.72 Zn1 0 .5 .5 1.82 Zn2 .5 0 .5 1.84 AsX .42101 .42320 .77763 1.74 OH1 .1554 .1572 .4059 3.10 O2 .3131 .3093 .6509 1.89 O3a .2495 .6831 .2581 2.56 O3b .6842 .2471 .2610 2.42 O4 .2786 .2874 .0085 5.03