Morphology, Technical and Treatment Study of Leaded Bronze, Applied on Some Archaeological Statues from Dhamar Museum, Yemen

A group of leaded bronze statuesfound during the archaeological excavation of Yemeni mission 2002 A. D, in Gabal al- lawd, Jawf area, Yemen and dated back to Minaean period in Yemen [sixth century B. C 24 B. C], are now in the Dhamar regional museum. They suffered deterioration: three of these statues had a thick corrosion products of pale-green / black, the others had a rust-colored Black and Brown with the presence of small parts and scattered pale green. The aims of this paper are to study bronze alloy to get a deeper insight into the morphology and mineralogy of corrosion products. The cause and mechanism of corrosion process to control and stop it, and to identify the types of corrosion products of selected objects as well as their constituting metals in order to carry out scientific treatment and conservation to avoid any further deterioration. To achieve that specimens from the statues were examined by Metallographic Microscope (ME) and Scanning Electron Microscope (SEM), while the corrosion products were analyzed by X-ray diffraction (XRD). X-ray Fluorescence ( XRF) was used to determine the bulk elements of the objects. XRD data showed that the corrosion products are cuprite, atacamite and paratacamite, whereas XRF analysis pointed out that the statues are composed by a leaded bronze alloy. Microscopic examination reveals that the statues suffered deterioration mainly in spots. Exploiting the collected info, chemical cleaning was chosen for treating the objects. Finally the obtained results helped us in treatment and conservation the selected objects.