Influence of Gamma Ray Irradiation on the Optical Properties of Calcite and Dolomite

Appl Spectrosc. 2020 May;74(5):507-514. doi: 10.1177/0003702819865935.

Abstract

The class of carbonaceous chondrite meteorites has carbon in their structures, similarly to the terrestrial calcite and dolomite rocks, and contains the group =CO3 linked to Ca and/or Mg, which may be, in principle, more susceptible to the action of the spatial gamma radiation (γ-R) due to the presence of these light-atom elements. On the present work, we used a variety of optical techniques to investigate the possible effects of γ-R produced by an artificial 192Ir source in terrestrial calcite and dolomite, which may allow to understand the effect of the spatial radiation in that celestial bodies of the solar system. As a result, we verified that the γ-R irradiation caused the effect of untrapping of electrons from deep color centers, that spatially migrate to other color centers on the samples, resulting on the change of the electron energetic configuration.

Keywords: Calcite; Raman scattering spectroscopy; X-ray diffraction; XRD; dolomite; meteorite; optical transmittance; photoluminescence; reflectance.