African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12191

Full Length Research Paper

Traditional mining and mineralogy of geophagic clays from Limpopo and Free State provinces, South Africa

  G-I. E. Ekosse1*, L de Jager2 and V. Ngole3  
  1Directorate of Research Development, Walter Sisulu University, Eastern Cape, South Africa. 2School of Health Technology, Central University of Technology, Bloemfontein, South Africa. 3Faculty of Science, Engineering and Technology, Walter Sisulu University, Eastern Cape, South Africa.  
Email: [email protected]

  •  Accepted: 28 June 2010
  •  Published: 22 November 2010

Abstract

 

This paper is based on responses to questionnaires administered to 226 representative geophagic adults in Limpopo (Polokwane and Sekhukhune) and Free State (Qwaqwa and Mangaung) Provinces in South Africa, and semi-quantitative mineral identification of 40 geophagic clay samples from the same areas. Geophagic clays consumed were whitish, yellowish, khaki and black; mined from hills and mountains, river beds, valleys, excavation sites and termitaria. Geophagic individuals from Free State preferred whitish geophagic clays; and sometimes khaki. Yellowish clays were preferred mostly by geophagic individuals from Limpopo. The clays are mined using selective digging, hand grabbing and picking techniques. The clays are processed through sieving, slurrying, grinding and pounding. Baking, burning and boiling are some beneficiation techniques used to render the clays more palatable and to reduce their microbial load. Mineral phases identified in the clay samples were quartz, kaolinite, mica, feldspar, smectite, goethite, calcite, and dolomite. The properties of kaolinite and smectite were found to have a dominant influence on the nature of geophagic clays and hence on the health of those who consumed the clays. Further details regarding the potential of geophagic clays to provide medicinal benefits to the consumer were examined in this study. Geophagic practice is very deep rooted, globally distributed, and has spanned over several centuries. Renewed interest and study by the scientific research community has continued to generate new knowledge on this somewhat enigmatic practice. Further efforts to address and regulate geophagic clay consumption should be strongly advocated.

 

Key words: Colour, heat treatment, kaolinite, pounding, sieving.