JOURNAL OF RAMAN SPECTROSCOPY J. Raman Spectrosc. 2008; 39: 289–294 Published online 21 January 2008 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/jrs.1892 Micro-Raman and particle-induced X-ray emission spectroscopy for the study of pigments and degradation products present in 17th century coloured maps Nuno Mendes, 1,2* C. Lofrumento, 1 A. Migliori 3 and E. M. Castellucci 1,2 1 Department of Chemistry, University of Florence, Polo Scientifico e Tecnologico, via della Lastruccia 3, I-50019, Firenze, Italy 2 European Laboratory for NonLinear Spectroscopy (LENS), University of Florence, Italy 3 Department of Physics, University of Florence and INFN, Sesto Fno. (FI), Italy Received 29 June 2007; Accepted 2 November 2007 Three different maps of the 17th century, two of them of Portugal and the third of the Iberian Peninsula, all of them hand coloured and of Dutch manufacture (copper engraving), were studied in this work. The study was carried out by using particle-induced X-ray emission (PIXE) and micro-Raman spectroscopy. These are two non-destructive techniques that provide complementary information on the composition of the materials: PIXE giving elemental information and Raman providing information at a molecular level. By means of the two techniques it has been possible to identify the inorganic pigments used in the three maps, as well as some products of degradation whose causes are not completely understood yet. This article contributes to a better knowledge of the techniques and palettes used for the colouring of maps of this period as well as the degradations of the pigments. Particular attention is given to the presence of a copper oxalate found in two different maps, its presence being associated with green coloured areas and indicating a degradation of a copper-based green pigment. Copyright  2008 John Wiley & Sons, Ltd. KEYWORDS: micro-Raman spectroscopy; PIXE; ancient maps; moolooite INTRODUCTION Raman spectroscopy and particle-induced X-ray emission (PIXE) are two well-established techniques for the study of a wide variety of materials of artistic interest 1–4 ; they have been used as a diagnostic tool for restoration and conservation and also for scientific studies on the nature of materials, their provenance and degradation. The fact that they provide complementary information, atomic for PIXE and structural or molecular for Raman spectroscopy, allows a rather complete characterization on the majority of inorganic materials. The difficulty of PIXE to detect low-Z elements (typically for Z < 12) due to the sample self absorptions limits its use for organic elements, also Raman spectroscopy has serious difficulties identifying many organic compounds due to fluorescence emission masking the weaker Raman bands. Of all the different materials that can be studied with these techniques, mineral pigments are the ones from which better and more specific answers can be expected. Furthermore, Raman spectroscopy and PIXE are essentially L Correspondence to: Nuno Mendes, Dipartimento Chimica, Universita di firenze Via della Lastruccia, 3 Sesto Fiorentino, 50019 Itally. E-mail: nuno@lens.unifi.it surface analysis techniques, and therefore are especially suited for the study of works on paper medium, such as miniatures, printings, watercolours and drawings, where the lack of protective varnish layers (as opposed to oil paintings) allows direct access to the pictorial materials without the need of any previous preparation of the works. The study of ancient maps Maps have been for long a rich source of geographical, historical and artistic information. The printing of a new map was usually done using the most updated techniques available and reflected the geographical and topographical know-how of that historical period. A particularly interesting characteristic of many maps is the aesthetic care taken in their presentation; the inclusion of animals or humans, fantastic and mythological creatures, coats of arms and compass roses served both to embellish the maps and provided practical information, increasing the commercial and artistic value of a map. 5 The use of colour in maps and town plans was another tool used to diminish the distance between art and technique: although the printing was done simply in black and white until the 18th century, many maps were hand coloured immediately before issue and map makers could Copyright  2008 John Wiley & Sons, Ltd.