Electron Microscopy Studies of the Composition and Microstructure of the Niello of Objects of Personal Piety of the 11th–13th Centuries from Suzdal’skoe Opol’e

Abstract

The results of studying the following three types of crosses with niello decor are given: encolpions decorated with the Crucifixion and the Orant Mother of God, encolpions with a simple cross in the center, and crosses worn next to the skin. All the items are finds discovered in the ploughed layer of rural settlements in the vicinity of Suzdal’. Variations in the composition of the metal of products correlate with their classification into morphological types. The main group of niello masses observed in most crosses (Cu–Pb–S) and its variation with an admixture of zinc (Cu–Pb–S–Zn) are distinguished according to the elemental composition of the niello. A variant of a similar composition with the addition of tin and zinc (Cu–Pb–Sn–S–Zn) is revealed in one composition, and one niello composition is unique in that it contains a large amount of zinc and a small amount of lead (Cu–S–Zn–Pb). Niello samples in which the zinc content is associated with the influence of the metal of the base are identified. There is no correlation between the types of crosses and the compositions of the niello. Based on the microstructures of the niello masses, samples that have been subjected to intense short-term heating during blackening or, conversely, exposed to insufficiently high temperatures for a long time are identified.