URI | http://purl.tuc.gr/dl/dias/059658E4-2921-4B71-88AB-D8176BDD06CF | - |
Identifier | https://doi.org/10.1346/CCMN.2006.0540601 | - |
Language | en | - |
Title | A new ni-rich stevensite from the ophiolite complex of othrys, central Greece | en |
Creator | Christidis Georgios | en |
Creator | Χρηστιδης Γεωργιος | el |
Creator | Ioannis Mitsis | en |
Publisher | Clay Minerals Society | en |
Content Summary | The first occurrence of Ni-rich stevensite found in the ophiolite complex of Othrys, Central
Greece is described. The stevensite, which develops in cracks in a host serpentinite, formed at the expense
of serpentine. Two varieties of stevensite have been described: a Mg-rich, Ni-poorer variety with 0.41.2
octahedral Ni atoms per half formula unit (p.h.f.u.) and a Ni-rich variety with >2 Ni atoms p.h.f.u. The
layer charge in both varieties is 0.24 p.h.f.u.. Stevensite layers are completely separated when dispersed
in dilute polyvinylpyrrolidone (PVP) solutions and begin to convert to talc after heating at 250ºC for
90 min. Total conversion to talc is observed at 550ºC. Formation of Ni-rich stevensite took place at
ambient temperature during supergene processes. The scarcity of Ni-rich stevensite occurrences in nature
is attributed to the metastability of smectite and to the analytical procedures used in previous studies.
Stevensite is considered a phase containing domains with variable numbers of octahedral vacancies. A new
experimental protocol is proposed for the determination of Ni-rich stevensite, based on a combination of
XRD after solvation with various organic liquids and subsequent heating at 750ºC. | en |
Type of Item | Peer-Reviewed Journal Publication | en |
Type of Item | Δημοσίευση σε Περιοδικό με Κριτές | el |
License | http://creativecommons.org/licenses/by/4.0/ | en |
Date of Item | 2015-10-01 | - |
Date of Publication | 2006 | - |
Bibliographic Citation | G.E. Christidis , I. Mitsis ,"A New Ni-rich stevensite from the ophiolite
complex of Othrys, central Greece ",Cl. and Clay Min. ,vol. 54, no.6 ,pp.653-666 ,2006.doi :10.1346/CCMN.2006.0540601 | en |