IDENTIFICATION OF THE ENDANGERED PINK-TO-RED STYLASTER CORALS BY RAMAN SPECTROSCOPY

Research areas:
Year:
2009
Authors:
  • Stefanos Karampelas
  • Emmanuel Fritsch
  • Benjamin Rondeau
  • Aude Andouche
  • Bernard Metivier
Journal:
GEMS & GEMOLOGY
Volume:
45
Number:
1
Pages:
48-52
Month:
SPR
ISSN:
0016-626X
BibTex:
Abstract:
All corals within the Stylasteridae family (including the Stylaster
genus) are listed in Appendix II of CITES; this means they are protected
and their trade requires an export permit, unlike corals from the
Corallium genus, which include most pink-to-red corals used in jewelry.
Raman scattering demonstrates that corals from the Stylaster genus
contain carotenoid pigments (polyenic pigments substituted with methyl
groups), whereas those from the Corallium genus are colored by
unmethylated polyenic pigments. Additionally, Stylaster corals are made
of aragonite, whereas those from Corallium are composed of calcite.
Through Raman scattering analysis, the fully protected Stylaster
pink-to-red corals may be distinguished from this other type of gem
coral.