#Dark blue patina truck crack#

The surface corrosion was also examined in order to understand the diagenetic processes affecting the preservation of the finds and their condition. An interesting aspect is the implication of science for the recognition of forgeries, when analytical studies provide evidences able to prove or deny objects' authenticity.Ī technical study was conducted on a group of copper alloy artifacts excavated from the burial tumulus of Lofkënd (fourteenth–ninth century BCE) to identify the alloy compositions and methods of manufacture. Furthermore, analytical techniques play an important role in the characterisation and evaluation of the effectiveness of protective coatings and corrosion inhibitors before and after restoration procedures. It is also underlined how a non-invasive approach might be used whenever no sampling is allowed, though some limitation should be considered. Through their use, it is possible to identify the material constitution, to evaluate the degradation behaviour and the state of conservation of excavated bronze artefacts. Typically, methods that require the withdrawal of a sample, such as metallography, SEM-EDS, AAS, FTIR and Py-GC-MS are employed.

The present review intends to give an overview on the type of information that is possible to gather from the application of different non-invasive and micro-destructive analytical techniques. Using the SEM–EDS, XRD and XRF and micro-Raman spectroscopies allowed corrosion products in the fragments to be successfully characterized in microchemical and structural. Also, the results obtained suggest a Type I of corrosion structure.

These results testify to a strong interaction of the alloy elements with soil components. The fragments also contained chloride and trihydroxychloride compounds such as nantokite (CuCl) and atacamite, respectively, which make conservation of archaeological objects troublesome. Based on the results, being buried for a long time caused the main elements in the alloy to mineralize and form stratified layers consisting of various mineral phases including cuprite (Cu 2 O), malachite and cassiterite (Sn 2 O).

The fragments were analyzed by using various instrumental techniques including electron scanning mi-croscopy coupled to energy dispersive X-ray spectroscopy (SEM–EDS), X-ray fluorescence (XRF) spectroscopy, and also by X-ray diffraction (XRD) and micro-Raman spectroscopy. The fragments came from a large bronze cauldron used in an Iberian village that was devastated in the mid II century BCE - possibly around 141 BCE. Selected bronze fragments unearthed at Cerro de la Cruz (Almedinilla, southern Spain) were analyzed to determine the chemical composition of the corrosion products formed on their surface. The surface of the Osiris statuette was protected with a corrosion inhibitor and protected against further corrosion attack with a protective coating. Mechanical cleaning was applied so as to remove the superficial deposits / encrustations in a controlled and minimally obstructive way and then reaching a smooth layer which preserves the detail and shape. The high amounts of tin and lead affected on the mechanical properties of the bronze alloy and surely on its deterioration. Structural examination and the elemental analysis by scanning electron microscopy (SEM) equipped with dispersive spectrome-try (EDS) proved that the statuette was made of bronze material of Cu-Sn-Pb alloy. X-ray diffraction (XRD) analysis revealed that the main compositions of the corrosion layer are oxychlorides, carbonates and sulphates covering copper and tin oxides. Stereo-microscopic images revealed the Pseudomorph phenomenon on its surface.

Its style belongs to the Lower Egyptian style, and the direct solid lost-wax technique was used in the manufacturing process. Visual and stylistic examinations revealed that it is most probably dating to the Third Intermediate Period (1070-664 BC) or the Late Period (664-323 BC).

#Dark blue patina truck crack#

The statuette is an uncommon case it was heavily corroded, covered with a thick crust of green corrosion products, has textile impression, missing its head, and has an unusual deep crack into its feet. Its period, its specific burial place, and the certain excavation date were unknown. It was temporarily inventoried with number 31/12/26/11C at the Egyptian Museum in Cairo. An Egyptian bronze statuette of the god Osiris has been discovered along with other ritual dei-ties' statuettes and other metallic ritual equipment at Sais.