M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)

Analysis - KRISTON László, JÁRÓ Márta: Impact of acid treatment of pigment samples from wall paintings on the result of paint identification by X-ray diffraction

Papers at the 5th International Restorer Seminar, National Centre of Museums, Budapest, 1985. 83-88 . 4. Giovanoli decomposed the interfering calcium-carbonate by warm acetic acid in some paint samples: R. Giovanoli: Provincial Roman wall paintings investigated by electron microscope, Archaeometry, 11 (1969) 53-59. Lazzarini applied 3N hydrochloric acid for the same purpose: L. Lazzarini: The discovery of Egyptian blue in a Roman fresco of the madiaeyal period (ninth century A.D.), Studies in Conservation, 27 (1982) 84. We decided to use the latter acid since it was assumed that even if the pigments containing lead are transformed, the transformation product will be retained in the pigments and their m direct identification will still be possible. 5. X-ray fluorescence spectra were taken of the surface of mural fragments by the isotope induction method (I

125 isotope, high purity aluminium underplate, diameter of irradiated surface: about 8 mm, duration of irradiation: 800 s). Herewith we should like to express our gratitude to László Költő, chemical engineer, who kindly undertook the carrying out of the examinations. Photos see on page 229