RT Journal Article
T1 On the chemical composition of sepiolite and palygorskite
A1 García Romero, Emilia
A1 Súarez Barrios, Mercedes
AB Many studies of the chemical composition of sepiolite and palygorskite have been carried outusing analytical electron microscopy (AEM). According to the literature, a compositional gap existsbetween sepiolites and palygorskites, but the results presented here show that they may all be intermediatecompositions between two extremes. The results of >1000 AEM analyses and structural formulae havebeen obtained for the samples studied (22 samples of sepiolite and 21 samples of palygorskite) and indicatethat no compositional gap exists between sepiolite and palygorskite. Sepiolite occupies the most magnesicand trioctahedral extreme and palygorskite the most aluminic-magnesic and dioctahedral extreme.Sepiolite and palygorskite with intermediate compositions exist between the two pure extremes:(1) sepiolite with a small proportion of octahedral substitution; (2) palygorskite with a very wide range ofsubstitution (the pure dioctahedral extreme is unusual); and (3) intermediate forms, Al-sepiolite and Mgpalygorskitewith similar or the same chemical composition. The chemical compositions of theintermediate forms can be so similar that a certain degree of polymorphism exists between Al-sepiolite andMg-palygorskite.
PB Clay Minerals Society
SN 0009-8604
YR 2010
FD 2010
LK https://hdl.handle.net/20.500.14352/41987
UL https://hdl.handle.net/20.500.14352/41987
LA eng
DS Docta Complutense
RD 7 abr 2025