Notes on Vestorius' Blue - New findings and investigations

Egyptian blue (EB) is amongst the first man-made pigments. Archaeological EB samples from Pozzuoli, Herculaneum and Pompei and modern EB mock-ups have been investigated by multianalytical approach: fibre optics reflectance spectroscopy (FORS), optical microscopy (OM), scanning electron microscopy with probe EDS (SEM-EDS) and particles induced X-ray emission (PIXE). To examine the effect of heating temperature and time on the properties of the produced pigment, modern EB samples were synthesized by varying firing temperature (850, 900, 950 degrees C) and time (tau = 1, 2 and 5 h). Some correlations, in terms of morphologic and colorimetric properties of produced material, related to the manufacturing temperature of firing are drawn. Moreover, the study confirms that there is a great variety of utilized substances linked to materials available for the manufacturer at the moment. (c) 2020 Elsevier Masson SAS. All rights reserved.