Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Montmorillonite

Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1025-2

Definition

Montmorillonite is a clay mineral of the smectite group, which also includes nontronite and saponite. It was first discovered in 1847 in Montmorillon in the Vienne region of France. It is usually white, gray, or pink with shades of green or yellow as a result of the metal oxide impurities it contains. It is often found in compact or lamellar masses, but never in large individual crystals. Its specific gravity varies between 1.7 and 3.0. It has a hardness of 1–2 in the Mohs scale (the Mohs scale ranges between 1 and 10, where 1 and 10 correspond to talc and diamond, respectively). Chemically, it is a hydrated aluminum silicate containing small amounts of magnesium, iron, sodium, calcium, and potassium as a result of isomorphic substitutions. The nature of these cations and their ratio within the mineral structure vary with the source of montmorillonite.

Overview

Montmorillonite (Grim 1968) has a layer structure with 2:1 arrangement: Each layer is composed of three sheets....

Keywords

Catalyst Cation exchange Clay minerals Oligomerization Origin of life 
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References and Further Reading

  1. Bernal JD (1949) The physical basis of life. Proc R Soc Lond A 62:537–558CrossRefGoogle Scholar
  2. Ertem G et al (2010) Correlation between the extent of catalytic activity and charge density of montmorillonites. Astrobiology 10:743–749, and references thereinADSCrossRefGoogle Scholar
  3. Grim RE (1968) Clay mineralogy. McGraw Hill, New YorkGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.National Institutes of HealthBethesdaUSA