Rebuilding of the Burial Environment from the Chemical Biography of Archeological Copper-Based Artifacts

Abstract

The long-term interaction between Cu-based alloys and environmental species gives rise to the formation of different and sometimes unusual compounds (i.e., the patina) with distinctive chemical and structural features as a function of the peculiar characteristics of the context. In this paper, we describe some representative case studies concerning degraded bronze Roman valuable or common use objects, and we show that an attentive study at a microscale level, as for forensic analysis, allows one to understand the chemical processes that underlie the formation of the surface alteration products. The achieved information describe fragments of chemical life and disclose the complex chemical changes suffered by the artifacts, allowing one to write their chemical biography. This challenging approach expands the panorama of available information and demonstrates that it is possible to reconstruct the different modes through which the bronze surfaces and interfaces have interacted with environmental species, organic matter, and microorganisms, opening up a new possibility to describe complex environmental chemical stories, in certain cases interrelated.

Non‐invasive surface analysis of ancient bronze arrowheads with scanning electron microscopy and X‐ray powder diffractometry

“…28 Metabolic activity of sulfate-reducing bacteria (SRBs) in the soil, producing copper and copper-iron sulfides in anaerobic conditions, could be another source of the element. 29,30 A noteworthy feature is the relatively high concentration of phosphorus in some cases. The element is sometimes present in iron-rich silicates mentioned above, but contact with decomposed organic matter like peat is also a possible source.…”

Removal of Copper Corrosion Products by Using Green Deep Eutectic Solvent and Bio-Derivative Cellulose Membrane

“…With technological and scientific progress, there is a strong expectation for greener and safer procedures for the removal of corrosion products such as from ancient metal artifacts. Copper was one of the first metals to be used by humans; copper-based artifacts have been the most frequently found objects in archaeological sites throughout history [ 1 ] and are generally found with a layer of naturally developed patina on their surfaces. Without any specific treatment, corrosion continuously spreads over the objects and destroys their fine structures.…”

Microstructure and phase composition of bronze Montefortino helmets discovered Mediterranean seabed to explain an unusual corrosion

“…There are several interesting cases studio about the possibility to reconstruct the history of a bronze artifact trough the analysis of patinas 14 i.e. Ingo et al identified by a turquoise crust the interaction of a roman coin with phosphorous released by animal bones discarded into the ancient sewer 15 or correlated the accumulation of metal on the Dancing Satyr with the marine context 16 .…”