{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["108(52)"],"submitter":["Spektor K"],"pubmed_abstract":["Stishovite (SiO(2) with the rutile structure and octahedrally coordinated silicon) is an important high-pressure mineral. It has previously been considered to be essentially anhydrous. In this study, hydrothermal treatment of silica glass and coesite at 350-550 °C near 10 GPa produces stishovite with significant amounts of H(2)O in its structure. A combination of methodologies (X-ray diffraction, thermal analysis, oxide melt solution calorimetry, secondary ion mass spectrometry, infrared and nuclear magnetic resonance spectroscopy) indicate the presence of 1.3 ± 0.2 wt % H(2)O and NMR suggests that the primary mechanism for the H(2)O uptake is a direct hydrogarnet-like substitution of 4H(+) for Si(4+), with the protons clustered as hydroxyls around a silicon vacancy. This substitution is accompanied by a substantial volume decrease for the system (SiO(2) + H(2)O), although the stishovite expands slightly, and it is only slightly unfavorable in energy. Stishovite could thus be a host for H(2)O at convergent plate boundaries, and in other relatively cool high-pressure environments."],"journal":["Proceedings of the National Academy of Sciences of the United States of America"],"pagination":["20918-22"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC3248481"],"repository":["biostudies-literature"],"pubmed_title":["Ultrahydrous stishovite from high-pressure hydrothermal treatment of SiO2."],"pmcid":["PMC3248481"],"pubmed_authors":["Haussermann U","Hervig RL","Nylen J","Spektor K","Leinenweber K","Stoyanov E","Navrotsky A","Holland GP"],"additional_accession":[]},"is_claimable":false,"name":"Ultrahydrous stishovite from high-pressure hydrothermal treatment of SiO2.","description":"Stishovite (SiO(2) with the rutile structure and octahedrally coordinated silicon) is an important high-pressure mineral. It has previously been considered to be essentially anhydrous. In this study, hydrothermal treatment of silica glass and coesite at 350-550 °C near 10 GPa produces stishovite with significant amounts of H(2)O in its structure. A combination of methodologies (X-ray diffraction, thermal analysis, oxide melt solution calorimetry, secondary ion mass spectrometry, infrared and nuclear magnetic resonance spectroscopy) indicate the presence of 1.3 ± 0.2 wt % H(2)O and NMR suggests that the primary mechanism for the H(2)O uptake is a direct hydrogarnet-like substitution of 4H(+) for Si(4+), with the protons clustered as hydroxyls around a silicon vacancy. This substitution is accompanied by a substantial volume decrease for the system (SiO(2) + H(2)O), although the stishovite expands slightly, and it is only slightly unfavorable in energy. Stishovite could thus be a host for H(2)O at convergent plate boundaries, and in other relatively cool high-pressure environments.","dates":{"release":"2011-01-01T00:00:00Z","publication":"2011 Dec","modification":"2024-11-14T08:23:37.008Z","creation":"2019-03-27T00:47:28Z"},"accession":"S-EPMC3248481","cross_references":{"pubmed":["22160677"],"doi":["10.1073/pnas.1117152108"]}}