Extended Defects and Vacancy Non-Stoichiometry in Rock-Forming Minerals

  1. Robert N. Schock
  1. David R. Veblen

Published Online: 18 MAR 2013

DOI: 10.1029/GM031p0122

Point Defects in Minerals

Point Defects in Minerals

How to Cite

Veblen, D. R. (1985) Extended Defects and Vacancy Non-Stoichiometry in Rock-Forming Minerals, in Point Defects in Minerals (ed R. N. Schock), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM031p0122

Author Information

  1. Department of Earth and Planetary Sciences, The Johns Hopkins University Baltimore, Maryland 21218

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1985

ISBN Information

Print ISBN: 9780875900568

Online ISBN: 9781118664070

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Keywords:

  • Mineralogical chemistry—Congresses;
  • Crystals—Defects—Congresses

Summary

Extended defects in minerals, both linear and planar, can have geochemically and geophysically important consequences. Whereas point defects can be investigated fruitfully with theoretical methods, transmission electron microscopy provides an important experimental tool for studying extended defects. In at least some cases, there may be a dynamic chemical relationship between point defect concentrations and the length or area of dislocations or planar defects in a crystal. Many solid-state reactions take place by mechanisms involving the nucleation and propagation of dislocations or planar defects. Extended defects also may alter the diffusion properties of minerals, especially important in the case of replacement reactions. Substantial non-stoichiometry resulting from the substitution of large proportions of vacancies on cation sites is a common feature in a wide variety of important rock-forming minerals and may provide an opportunity for studying the detailed structural properties of vacancies.