coral, spectroscopy, raman spectroscopy, gems

Dele-Dubois and Merlin investigate the pigments responsible for the coloration of the calcareous skeleton of coral using Raman spectroscopy. The technique permits direct, non-destructive examination of the colored material and characterization of the pigments from their Raman spectra, helping distinguish coloration intrinsic to the coral skeleton from other causes of color. The study demonstrates the value of Raman spectroscopy for identifying organic pigments in gem coral and for investigating the relationship between skeletal composition and coloration, with potential application to the gemological examination of natural coral.