Chukanov N. V., Kotel’nikov A. R., Pekov I. V., Van K. V.

To the question about conditions of the mineral-forming of cancrisilite Na7(Al5Si7O24)(CO3)·3H2O and “hydrocancrinite” Na6(Al6Si6O24)·4H2O (on the base of data of their synthesis)

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2019. V. 148. N 5. P. 135-144

Full text is available on

Full text is available on eLIBRARY.RU

Language: Russian 


Aluminosilicates with a cancrinite-type structure compositionally related to cancrisilite and a Ca-free and CO3 — deficient cancrinite analogue were synthesized and characterized by electron microprobe and HCN-analyses, IR spectroscopy, and powder X-ray diffraction. The empirical formulae of the compounds obtained are H0.05Na6.13[Al4.36Si7.64O24](CO3)0.91 · 2.85H2O and H0.07Na6.19[Al5.53Si6.47O24]·(CO3)0.365 · 3.915H2O, respectively. The latter compound is characterized by disordered chains (···Na···H2O) in the narrow channel and a high content of H2O in the wide channel. The conditions for the formation of cancrisilite and carbonate-deficient cancrinite varieties in nature are discussed. It was concluded that supercritical conditions and ultra-agpitic environment contribute to crystallization of cancrisilite.

Key words: cancrinite-group minerals, cancrinite, cancrisilite, hydrothermal synthesis, IR spectroscopy, powder X-ray diffraction