Analysis of a royal 15th century illuminated parchment using a portable XRF–XRD system and micro-invasive techniques

Abstract A system of complementary X-ray diffraction (XRD) and fluorescence (XRF) was used for non-invasive in situ identification of inorganic materials in a highly valuable illuminated parchment, now preserved at the Archive of the Royal Chancellery in Granada (Spain), via which King Enrique IV (1425–1474) conferred nobility on Gil Fernandez and Alonso Covo. The study of organic matter, by capillary electrophoresis (CE), could not be performed without taking microsamples that had also been used to confirm – by micro-Raman spectroscopy and scanning electron microscopy (SEM–EDX) – the nature of inorganic materials that had been identified by XRD–XRF. Gold and silver were detected as well as lead tin oxide in yellow, azurite in blue, vermilion and minium in reddish colours and malachite in green. Calcite was applied to the entire sheets and gypsum to the text area. Iron-based ink was used for the parchment text. These analyses enable the document to be put into its historical context; they serve as a starting point in a comparative study with other similar documents, for the reconstruction of its documentary archaeology.