Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Letter to editor

Jakub Plášil, Jiří Čejka

A note on the molecular water content in uranyl carbonate mineral andersonite

Journal of Geosciences, volume 60 (2015), issue 3, 181 - 187

DOI: http://doi.org/10.3190/jgeosci.193

The crystal structure of andersonite from Jáchymov (western Bohemia, Czech Republic) was refined from single-crystal X ray diffraction data to an R = 0.0286 against 1657 unique observed reflections. Andersonite from Jáchymov is trigonal, R-32/m, with a = 17.8589(6), c = 23.6935(8), V = 6544.4(4) ų and Z = 18. The structural formula derived from the refinement of X-ray data is Na₂Ca[(UO₂)(CO₃)₃](H₂O)_5.28. This formula confirms previous structure determination on synthetic material. The maximal H₂O content in andersonite is discussed also with regard to the published thermal analysis and vibration spectroscopy studies and disunities in chemical formula of andersonite in the literature.