Identification of antique silver jewelries by microstructure

Abstract

Background. The high cost of silver jewelries, including art and antiques, causes increasing role in the identification of any assessment activities, primarily commodity expertise. An important identification indicator characterizing time of creation of silver items is microstructure.
The aim of the article is to define the microstructure and chemical composition of antique silver jewelries.
Material and methods. Objects of the research were silver jewelries made in different chronological periods. Determination of the microstructure of silver jewelry items was carried on scanning electron microscope. The study of the chemical composition of antique silver jewelries was made by X-ray microanalysis.
Results. The obtained images of Sarmatian glass of I century BC, the cup of the end of XVII century, coffee spoon production in 2004 indicate differences in the microstructure of silver alloys, which is an important feature for their identification. Along with this the study sample was analyzed by chemical composition by X-ray microanalysis, which revealed light elements Ca, P, Cl in the alloy of silver of I century BC. Modern jewelries contain mostly other chemical admixture elements: Fe, Pb, Sb, Bi, O. For the most part they are modifying.
Conclusion. Research of microstructure of silver jewelries of various chronological periods has shown its heterogeneity, particularly in antiques. The presence of larger grains compared to modern products indicates slow cooling during production. The presence in silver alloys of I century BC light admixtures shows the hallmarks of a manufacturing technology, the use of other raw materials.