gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1977.041.319.07 The Structure Of Chloroxiphite, Pb3CuO2 (OH)2 Cl2* Finney J. J. Department of Geology, Colorado School of Mines, Golden, Colorado 80401 Graeber E. J. Sandia Laboratories, Albuquerque, New Mexico 87115 Rosenzweig A. Department of Geology, Oberlin College, Oberlin, Ohio 44074 Hamilton R. D. Department of Geology, Colorado School of Mines, Golden, Colorado 80401

This work was supported by the U.S. Energy Research and Development Administration.

 9 1977 41 319 357 361 15 4 1976 6 9 1976 Copyright © 1977, The Mineralogical Society 1977 Summary

Chloroxiphite, Pb3CuO2(OH)2Cl2, is monoclinic, space group P21/m, with a = 10·458, b = 5·750, c = 6·693 Å, β = 97·79°, Z = 2. The structure has been refined by the method of least squares from three-dimensional Mo-Kα intensity data to a conventional R value of 0·115. The structure consists of sheets of composition [Pb3 CuO2(OH)3]2−, in themselves made up of the layer sequence Pb-(O, OH, Cu)-Pb, lying parallel to (1¯01). The structure contains eight-fold PbO4Cl4 and seven-fold PbO5Cl2 polyhedra common in other oxychlorides, Pb6 clusters and copper atoms in square planar, Cu(OH)4, coordination.