Synthetic arsenic sulfides in Japanese prints of the Meiji period

A multi-analytical investigation of Japanese woodblock prints ranging in date from 1864 to 1895 and covering essentially the time span between the very end of the Edo period and the middle of the Meiji period showed a widespread use of arsenic sulfides for yellow and green colored areas (the latter obtained by mixing Prussian blue to the yellow arsenic sulfides). Analysis by optical microscopy, X-ray fluorescence spectroscopy, Raman microscopy, and Scanning Electron Microscopy confirmed that the yellow pigment is usually a compound belonging to the solid solution series (As8S8)-(As8S9). The poor crystallinity of the pigment as shown by Raman microscopy, the non-stoichiometric As/S ratio, as well as the presence of excess uncombined sulfur point to a synthetic origin for the pigment. Period literary sources suggest that synthetic arsenic sulfide pigments manufacture might have started in the Iwashiro province in 1846. This is to our knowledge the first conclusive evidence for the use of synthetic arsenic sulfides in woodblock prints in Japan.