MULTI-ANALYTICAL TECHNIQUES OF A HISTORICAL VALUABLE OTTOMAN ENAMELED OFFICE CREW

This study aims to investigate enameled office crew collections from the Faculty of Applied Arts' Museum in Cairo, Egypt. It is a unique collection that is widely distributed in several international museums. Most recent studies have emphasized the importance of studying this type of metal and learning about ancient decoration techniques, causes, and common deterioration manifestations. The collection was embellished with various opaque and transparent enamel colors, as well as champlevé and painting enamel methods. This study explores a rare collection dating back to the Ottoman era, particularly the eras of Sultan Abdul Hamid II (1293-1327 AH/1876-1909 AD) and Khedive Abbas Hilmi II (1320-1333 AH/1892-1914 AD, which is characterized by a unique decorative style. Various analytical techniques were used to determine and investigate the office crew collection. The enamel, metal, and degradation properties were ascertained by analytical methods, such as visual assessment, portable digital microscope, portable X-ray fluorescence, and scanning electron microscope with energy-dispersive X-ray spectroscopy (SEM/EDX). The findings indicated that the metal substrate of each piece in the collection is an alloy of copper and silver, with iron making up a portion of two of the pieces. Also, gold remains were found on the obverse and in a few additional spots, which were not visible due to the black layer covering all parts of the pieces. Furthermore, the examination helped identify the deterioration manifestations of the office crew, including tarnish throughout the metal surface, enamel scratches, pits, fissures, and microcracks. The enamel investigation revealed the presence of silica, potassium, sodium, calcium, and lead; nevertheless, the color tone was attributed to the extremely low quantities of Cu and As and some special cases for each enamel color with the discovery of a unique technique for applying red enamel to the surface of the pieces. The results of the elemental analysis affirmed the authenticity of this collection.