Isothermal crystallization of szomolnokit from metastable synthetic pyrrhotites

The crystal structure and the phase composition of synthesized pyrrhotites after their endurance in the atmosphere of the Earth for 29 years at the temperature about 20ºС have been studied using the methods of X-ray structural analysis. Samples contain szomolnokit which was absent in initial samples. The analysis of experimental facts allows assuming that szomolnokit was formed from pyrrhotites in a metastable phase. The regularity of szomolnokit formation depending on the percentage of pyrrhotites and also on the sulfur to iron ratio in samples has been investigated. The diagram of pyrrhotites - szomolnokit phase ratio has been built. The theoretical model of phase pyrrhotite transition into szomolnokit is offered. As the result of quantum-mechanical calculations good conformity of the calculated diagram of pyrrhotite - szomolnokit phase ratio curve with the experimental one has been obtained. The calculations performed in the offered model of secondary quantization cohere well with similar calculations done within the model of a molecular field.