Publication: Trace elements and mineral chemistry of silicified wood from Thailand: colours and elemental distribution
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Issued Date
2016
Resource Type
File Type
application/pdf
ISSN
8120099
Other identifier(s)
2-s2.0-84999622168
Rights Holder(s)
Scopus
Bibliographic Citation
Australian Journal of Earth Sciences. Vol 63, No.7 (2016), p.873-884
Suggested Citation
Saminpanya S. Trace elements and mineral chemistry of silicified wood from Thailand: colours and elemental distribution. Australian Journal of Earth Sciences. Vol 63, No.7 (2016), p.873-884. doi:10.1080/08120099.2016.1251492 Retrieved from: https://hdl.handle.net/20.500.14740/5067
Author(s)
Abstract
Thai silicified woods were examined using electron probe microanalysis, yielding chemical data that characterised the samples into two groups: low and high silica contents (82—94 wt% and 94—98 wt%). The elements analysed in order of abundance include Si > Fe > Ca > Na > Al > Ti > K > Mg > Mn > Zr. Iron plays a major role in the colour range (red, orange, yellow, brown, grey and black) of the samples. Calcium is associated with Fe in the darker colours of the wood. Pseudo-crystallochemistry has been used for the substitution of trace elements for Si4+ in silica polymorphs. The atomic channels that run parallel to the c-axis of silica polymorphs or lattice defects, or even the charge balance for trivalent-ion substitution for Si4+, can accommodate monovalent ions (K+ and Na+). Vacant and atomic cavities, which are charged balanced by trivalent ions [Al3+ or Fe3+ substituting for Si4+], are commonly occupied by divalent ions (Ca2+, Mg2+ and Mn2+). Quadrivalent ions, Ti4+ and Zr4+ are non-structurally incorporated but form clusters of mineral inclusions in the samples. Several other trace-element contents are also in the form of mineral/fluid inclusions hosted in the woods. © 2016 Geological Society of Australia.