A note on the characterization of bismuth black by Raman microspectroscopy

Abstract Inspired by the discovery of bismuth metal used as a pigment in a fifteenth century illuminated manuscript, the identification of bismuth compounds by Raman spectroscopy is investigated. Raman spectra of bismuth metal powder, bismuth (III) sulfide (Bi 2 S 3 ) and bismuth (III) oxide (α‐Bi 2 O 3 ) are presented. The influence of excitation laser wavelength is explored, along with the laser‐induced oxidation of bismuth to α‐Bi 2 O 3 and β‐Bi 2 O 3 . The implication of these results with respect to the selection of appropriate analytical protocols in the investigation of bismuth pigments in works of art is discussed. Copyright © 2009 John Wiley & Sons, Ltd.