Hyperfine Interactions

, Volume 195, Issue 1–3, pp 55–62 | Cite as

Mineralogical characterization of Greda clays and monitoring of their phase transformations on thermal treatment

  • E. Chavez PanduroEmail author
  • J. Bravo Cabrejos


The mineralogical characterization of two clay samples from the Central Andean Region of Peru, denominated White Greda and Red Greda, is reported. These clays contain the clay minerals mica and illite respectively. Both clays were treated thermally in an oxidising atmosphere under controlled conditions up to 1,100°C with the purpose of obtaining information about structural changes that may be useful for pottery manufacture. X-ray fluorescence was used for the elemental characterization of the samples and X-ray diffractometry was used to determine the collapse and formation of the mineral phases present in the samples caused by thermal treatment. At temperatures above 1,000°C it is observed the formation of spinel in the case of White Greda and of hematite, corundum and cristobalite in the case of Red Greda. Room temperature transmission Mössbauer spectroscopy allowed the monitoring of the variation of the hyperfine parameters with the thermal treatment temperature; In the case of the evolution of the quadruple splitting of the paramagnetic Fe3 +  sites with temperature, in both clays, the analyses reproduced results such as the “camel back” curve shape, found by other workers (Wagner and Wagner, Hyperfine Interact 154:35–82, 2004; Wagner and Kyek, Hyperfine Interact 154:5–33, 2004).


Greda Mica Illite X-ray diffractometry Transmission Mössbauer spectroscopy Thermal treatment 


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  1. 1.
    Yuanfu, H., Hongbo, H.: Mössbauer studies in Chinese archaeology. Hyperfine Interact. 150, 33–50 (2004)Google Scholar
  2. 2.
    Carrol, D.: Clay minerals: a guide to their X-ray identification. The Geological Society of America Special Paper 126 (1970)Google Scholar
  3. 3.
    Wagner, F.E., Wagner, U.: Mössbauer spectra of clays and ceramics. Hyperfine Interact. 154, 35–82 (2004)CrossRefADSGoogle Scholar
  4. 4.
    Wagner, F.E., Kyek, A.: Application of Mössbauer spectroscopy to archaeology: introduction and experimental considerations. Hyperfine Interact. 154, 5–33 (2004)CrossRefADSGoogle Scholar
  5. 5.
    Moore, D.M., Reynolds, R.C.: X-ray Diffraction and the Identification and Analysis of Clay Materials, 2nd edn. Oxford University Press, Oxford (1997)Google Scholar
  6. 6.
    Brown, G.: The X-ray Identification and Crystal of Clay Mineral. Mineralogical Society, London (1961)Google Scholar
  7. 7.
    Bravo, J.A., Cerón, M.L., Fabián, J.: Optimization criteria in Mössbauer spectroscopy. Hyperfine Interact. 148/149, 253–261 (2003)CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Facultad de Ciencias FísicasUniversidad Nacional Mayor de San MarcosLimaPerú

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