gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1984.048.348.15 Some Observations on the Properties of Dypingite, Mg5(CO3)4(OH)2·5H2O, and Related Minerals Canterford J. H. Tsambourakis G. CSIRO, Division of Mineral Chemistry, PO Box 124, Port Melbourne, Vic, 3207, Australia Lambert B. Causmag International (Devex Limited), PO Box 438, Young, NSW, 2594, Australia

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 9 1984 48 348 437 442 10 10 1983 28 11 1983 Copyright © 1984, The Mineralogical Society 1984 Abstract

Dypingite, Mg5(CO3)4(OH)2·5H2O, was found in materials obtained during the production of high purity magnesia from crude magnesite by the calcination/CO2-leaching process. The snow-white, finely crystalline dypingite contained 41.0% MgO; the theoretical value is 41.5%. The X-ray powder data revealed a long period structure with a strong peak at 31.0 Å. The five strongest reflections (Å) and their estimated intensities (I/I0) were 10.4 (100), 31.0 (40), 15.62 (40), 5.86 (30), and 6.34 (20). The DTA curve showed ten endothermic reactions with maxima at 43, 50, 77, 86, 105, 127, 180, 260, 420, and 514°C and an exothermic reaction at 495°C.