Technical Study of Ethiopian Copper Alloy Processional Crosses Using Non-Destructive Analysis

Abstract

ABSTRACT The materials and techniques used to make Ethiopian copper and copper alloy processional crosses from the twelfth to twentieth centuries were investigated through technical study including X-ray fluorescence analysis (XRF). All 20 crosses in this multi-collection study underwent XRF analysis while the eight crosses from the collection of the Virginia Museum of Fine Arts additionally underwent X-radiography and scanning micro-XRF. The documentation of fabrication methods and repairs was carried out using non-destructive methods, including the application of scanning micro-XRF, which in this study, proved to be especially valuable for identifying and mapping solder and cast-on repairs. Additionally, results from XRF analysis confirmed patterns in alloy type related to cross style and chronology. Specifically, bronze was identified as the alloy used to make the earliest (twelfth – fourteenth century) crosses, while the later crosses (post fifteenth century) were found to be made of brass and gunmetal. Crosses dating to what appears to be a transitional period during the fourteenth – fifteenth century were found to be made of a greater variety of materials including copper, bronze, and brass. While the difference in alloy types found in crosses from different time periods may be related to changing preferences or access to certain metals, the mass removal of religious art in the sixteenth century could have also impacted the types of crosses that remain.