Micro-Raman and portable raman spectroscopic investigation of blue pigments in selected Delft plates (17-20th century)

Abstract

The blue pigment as well as other materials in a blue, white and 'gold' 17th century Delft dish were analysed and compared to the blue pigment(s) used in a modern blue-and-white Delft dish, obtained from a tourist shop in Amsterdam in 2004. The ancient Delft blue pigment was compared to a commercial Delft blue powder identified as a cobalt-doped willemite, Zn2-xCoxSiO4. The 17th century Delft pigment showed a closer correspondence to the olivine, alpha-cobalt silicate. The pigment in the modern blue Delft dish was mainly a vanadium-doped zircon, ZrSiO4:V4+, with small amounts of cobalt, identified by EDX analysis. The cobalt compound could, however, not be characterisedherefor themodern dish. Thepigment in the'golden' rim was identified as pyrochlore yellow, PbSnSbO6.5. © 2009 John Wiley & Sons, Ltd.