W0015

Structure and Composition of Naples Yellow. Joris Dik^*, Frans Tichelaar^**, Kees Goubitz^*, Rene Peschar^* and Henk Schenk^*, ^*Laboratory for Crystallography, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, the Netherlands, ^**Delft Technical University, National Center for HREM, Rotterdamseweg 137, 2628 AL Delft, the Netherlands.

The pigment Naples Yellow, or lead antimonate yellow, is ubiquitous in Western visual art. Naples yellow was used mainly as a painting pigment in the period from 1500 to 1900 AD. The composition and structure of this synthetic pigment, nominally consisting of lead antimony oxide (Pb₂Sb₂O₇), varies significantly due to differences in production methods. This opens the possibility to date and locate paintings when the variation of composition over time and place is known.

Authentic pigment material was collected by sampling a number of historical paintings of known origin. Paintings sampled include works from the Rijksmuseum, Amsterdam and the Getty Museum, Los Angeles. In addition samples were taken from various historical pigment collections, including the Hafkenscheidt Collection at the Teylers Museum (Haarlem, the Netherlands) and the Turner Pigment collection at the Tate Gallery (London, UK). Lead antimonate samples of these and other collections were studied using a variety of analytical techniques, such as Transmission Electron Microscopy (TEM), combined with Energy Dispersive Spectroscopy (EDS) and X-ray and synchrotron radiation Powder Diffraction (XRDP).

The results show interesting characteristics of lead antimonate yellows from different periods and geographical origins.