The behavior of zeolites wairakite and phillipsite at high P-T parameters

Ulyana Borodina; Sergey Goryainov; Svetlana Krylova; Alexander Vtyurin; Alexander Krylov

doi:10.1016/j.saa.2022.120979

The behavior of zeolites wairakite and phillipsite at high P-T parameters

Spectrochim Acta A Mol Biomol Spectrosc. 2022 May 15:273:120979. doi: 10.1016/j.saa.2022.120979. Epub 2022 Feb 2.

Authors

Ulyana Borodina¹, Sergey Goryainov², Svetlana Krylova³, Alexander Vtyurin³, Alexander Krylov³

Affiliations

¹ Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, pr. Acad. Koptyug 3, 630090 Novosibirsk, Russia. Electronic address: borodinauo@igm.nsc.ru.
² Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, pr. Acad. Koptyug 3, 630090 Novosibirsk, Russia.
³ Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Academgorodok 50/38, 660036 Krasnoyarsk, Russia.

PMID: 35183854
DOI: 10.1016/j.saa.2022.120979

Abstract

In situ investigation of mineral behavior in water medium at simultaneously high P-T parameters can be applied to modelling of mineral transformation processes in lithospheric plates. The behavior of zeolites wairakite and phillipsite under the P-T conditions of «cold» slab subduction, corresponding to the start of oceanic plate diving or ocean floor near geothermal sources, was studied by in situ Raman spectroscopy. During compression in water medium, phillipsite initial phase is stable up to T = 350 °C, P = 1.7 GPa and with further increase of P-T parameters, phillipsite undergoes amorphization and partially dissolves in water. Wairakite compressed in water medium has a polymorphic transformation at T ≈ 300 °C and P ≈ 0.4 GPa. At 300-450 °C and P = 1 GPa the Raman spectrum almost disappears due to the amorphization of wairakite. Zeolite wairakite partially dissolves, and other zeolite phillipsite grows out of the fluid at T = 450 °C and P = 1 GPa. This transformation indicates the higher stability of phillipsite in comparison to wairakite. The in situ observed high P-T stability of phillipsite, which does not transform to other zeolites, and its formation from wairakite may indicate ф possible widespread distribution of this zeolite in marine sediments. By using the plane-wave pseudo-potential method, ab initio DFT calculations of Raman and FTIR spectra of wairakite were carried out. Comparing theoretical and experimental spectra, interpretation of the vibrational spectra of both zeolites was suggested.

Keywords: High pressure; High temperature; Phillipsite; Raman; Wairakite; Zeolites.