%0 Journal Article
%A García Romero, Emilia
%A Súarez Barrios, Mercedes
%A Bustillo Revuelta, María Ángeles
%T Characteristics of a Mg-Paylorskite in Miocene rocks, Madrid basin (Spain)
%D 2004
%@ 0009-8604
%U https://hdl.handle.net/20.500.14352/49736
%X Palygorskite in Miocene mudstones, palustrine limestones and calcretes from the Esquiviaslocality (Madrid Basin, Spain) has been analyzed by X-ray diffraction, infrared spectroscopy, scanningelectron microscopy, transmission electron microscopy and analytical electron microscopy to determine itscharacteristics and chemical composition. Other palygorskites from the literature are used as references.The mean structural formula obtained from the analysis of isolated particles is(Si7.87ALO.13)O20(Al1.04Fe3+0.20Mg3.11&0.65)(OH)2(OH2)4(Ca0.02K0.05Na0.08). This palygorskite has thelargest Mg content reported in the literature, and it seems that, chemically, it fills the ‘compositionalgap’ existing between sepiolite and palygorskite. Infrared spectroscopy reveals the absence of trioctahedralMg and therefore the possibility of the existence of magnesic clusters in the ribbons is discounted. Anhomogeneous distribution of the octahedral cations (Al, Fe3+ and Mg) along the ribbons is proposed.
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