Home – Home – Jornals – Russian Geology and Geophysics 2002 number 2

The mode of occurrence of cadmium in stoichiometric pyrrhotite synthesized hydrothermally at 450^oC and 1 kbar was studied by combined atomic absorption spectroscopy and thermal analysis. The results, along with the available data on relatively highly fugitive elements (Cd, Pb) in solid phases, show that sorption may play a key role in the intake of incompatible elements during crystal growth under the PT-conditions of endogenic mineral formation. Incompatible elements in a growing crystal form an adsorbed surface compound or a complex if their concentration is relatively low or a surface nonautonomous phase if their concentration approaches the saturation limit. Of this concentration, only a small portion may be in the structural form, and special techniques are thus required to separate it if the occurrence limit of the elements is estimated by routine methods.