Cathodoluminescence for Geosciences and Archaeology

Session AAP :

AAP 2023-1

Scientific responsibility :

  • Laurence Le Callonnec
  • Jean-Baptiste Houal
  • Karim Benzerara
  • Jocelyn Barbarand

Partnership :

Funding :

  • ISTeP
  • AOrOc

Project ID : IDF-DIM-PAMIR-2023-1-006

Summary :

Cathodoluminescence microscopy is a rapid and effective method for detecting chemical variations in minerals and identifying different generations of crystallisation. The current installation available at Sorbonne University is moe than 25 years old cathodyne coupled with an optical microscope and a Nikon digital reflex camera. The new equipment will significantly improve the ease of use ot this technique, analytical conditions and performance. The production of a mosaic image of the sample analysed will be easier and more accurate in terms of analytical conditions.
The cathodoluminescence phenomenon makes it possible to observe an object differently from the cross polarised light optical microscope or the binocular magnifying glass by highlighting (i) the presence of defects or impurities in the structure of the solid; (ii) the presence of exciting chemical elements called activators, crystallographic or biological growth streaks, zonations, dissolution/recrystallisation processes, distinguishing polymorphic crystals (e.g. calcite/aragonite) etc… This analytical technique provides additional information about the structure and composition of a natural or man-made object. It is also a key prerequisite for chemical determinations and radiometric dating.
The objects analysed are in the form of thin uncovered slides, but the analysis chamber can also be used to introduce samples with a surface area of centimetres and a thickness of millimetres. The technique is therefore non-destructive. Long used in the geosciences, this technique has shown great potential in archaeometry, particularly for characterising original materials such as ancient marble and for identifying the manufacturing processes of ceramics and glass.