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In antiquity, Pb was a common element added in the production of large bronze artifacts, especially large statues, to impart fluidity to the casting process. As Pb does not form a solid solution with pure Cu or with the Sn–Cu alloy phases, it is normally observed in the metal matrix as globular droplets embedded within or in interstitial positions among the crystals of Sn‐bronze (normally the α phase) as the last crystallizing phase during the cooling process of the Cu–Sn–Pb ternary melt. The disequilibrium Sn content of the Pb droplets has recently been suggested as a viable parameter to detect modern materials [Shilstein, Berner, Feldman, Shalev & Rosenberg (2019). STAR Sci. Tech. Archaeol. Res.5, 29–35]. The application assumes a time‐dependent process, with a timescale of hundreds of years, estimated on the basis of the diffusion coefficient of Sn in Pb over a length of a few micrometres [Oberschmidt, Kim & Gupta (1982). J. Appl. Phys.53, 5672–5677]. Therefore, Pb inclusions in recent Sn‐bronze artifacts are actually a metastable solid solution of Pb–Sn containing ∼3% atomic Sn. In contrast, in ancient artifacts, unmixing processes and diffusion of Sn from the micro‐ and nano‐inclusions of Pb to the matrix occur, resulting in the Pb inclusions containing a substantially lower or negligible amount of Sn. The Sn content in the Pb inclusions relies on accurate measurement of the lattice parameter of the phase in the Pb–Sn solid solution, since for low Sn values it closely follows Vegard's law. Here, several new measurements on modern and ancient samples are presented and discussed in order to verify the applicability of the method to the detection of modern artwork pretending to be ancient. [ABSTRACT FROM AUTHOR]

A systematic and extensive analytical study was carried out on the loose inlays discovered in the Ptolemaic workshop of Tebtynis (Fayum oasis, Egypt). This paper presents data derived from the multi‐methodological archaeometric investigations (optical microscopy, scanning electron microscopy–energy‐dispersive spectroscopy, electron probe microanalysis, micro‐Raman spectroscopy) performed on a set of intentionally colored and opacified glasses. In particular, we will discuss the textural, chemical, and mineralogical results related to the study of the yellow, yellowish‐orange, red, and brown inlays and semi‐finished/waste products now preserved at the Museo Egizio, Torino. The results highlight the presence of natron (low‐magnesium glasses, LMG) and plant ash (high‐magnesium glasses, HMG) base glass, coexisting with intermediate composition. Yellow samples are opacified using lead antimonates doped with iron and sometimes tin; conversely, yellowish‐orange specimens and the only brown sample are characterized by nanocrystals of cuprite. Red glasses are found in two variants: Dull reds are HMG with colloidal metallic copper particles, while sealing‐wax reds show LMG composition, associated with dendritic cuprite dispersed in a transparent, greenish matrix. [ABSTRACT FROM AUTHOR]

Inlays range among the most aesthetically pleasing and technically challenging glasses produced in the Ptolemaic period. Despite the central role of this phase in the history of glass technology, little is known about the recipes and the technological knowledge of the Egyptian artisans. This paper will thus focus on the study of the materials from the secondary workshop of Tebtynis (Fayum oasis, Egypt). We report the first multi‐methodological study comprising textural, chemical, and mineralogical analyses (optical microscopy, scanning electron microscopy coupled with energy‐dispersive system, electron probe microanalysis, and μ‐Raman spectroscopy) on a set of 81 colorless, white, blue, and green samples carefully selected among the 800+ glasses from the craft area now stored at the Museo Egizio, Turin (Italy). Our study offers the biggest compositional database of well‐dated Ptolemaic glasses currently available in the literature, highlighting some interesting novelties regarding the silica and alkali sources, and the coloring and opacifying techniques employed. The results suggest a specialized craft of traditional origin, but open to innovation and experimentation, as expected from transitional phases. [ABSTRACT FROM AUTHOR]