Conducting an X-Ray Fluorescence Investigation on Irish Chalices

A recent investigation from Ireland demonstrated how X-ray fluorescence (XRF) spectroscopy can be used to understand the composition and craftsmanship of ancient artifacts, according to a study published in Heritage Science (1). This study, led by Daniela Iacopino from the Tyndall National Institute in Cork, Ireland, examined three Irish chalices: the Ó Learghusa chalice, which was auctioned as medieval Irish in 2021 without confirmed provenance; the de Burgo-O'Malley chalice, dated 1494; and the TP-IEP chalice, dated 1589. These chalices are emblematic of the rich artistic and cultural heritage of medieval Ireland, and the findings from this study provide invaluable insights into their history and construction (1).

Coast of Northern Ireland | Image Credit: © stifos - stock.adobe.com

XRF analysis has long been used as a technique to study art and historical artifacts. From Jackson Pollock’s studio to Puebla ceramics, XRF is the technique of choice thanks to its noninvasive analysis (2,3). Here, the research team used XRF analysis to learn more about the construction of these three Irish chalices. They learned that both the Ó Learghusa and de Burgo-O'Malley chalices were crafted from a silver-copper (Ag/Cu) alloy and adorned using a fire-gilding technique, a method involving the application of a thin layer of gold to the surface of the silver (1). This technique not only enhanced the visual appeal of the chalices, but it also offered a degree of protection to the underlying metal.

Looking closely at the de Burgo-O’Malley chalice, the research team was able to determine that the blue and green enamels were made of cobalt (Co) and iron/copper (Fe/Cu) glasses, respectively (1). This discovery is particularly significant because it reveals the materials and methods used by medieval Irish artisans to achieve the vibrant colors and intricate designs that characterize this chalice.

In contrast, the TP-IEP chalice exhibited a more complex structure. It is a composite object featuring partial silver gilt and components made from a ternary alloy of silver, copper, and gold (Ag/Cu/Au) (1). The bowl and base of the chalice might not be contemporary with the rest of the chalice, suggesting that these parts could have been added or altered later (1). The chalice's knop, adorned with glass simulating gems in transparent, blue, and purple hues, was identified as being composed of lead-potash glass (1). Notably, lead-potash glass was not produced before 1674, indicating that the decorative elements of the TP-IEP chalice might have been added well after its initial creation (1).

Moreover, the analysis of the red glass on the TP-IEP chalice revealed a high iron content and identified it as soda-lime glass. This finding adds another layer of complexity to the chalice's composition and suggested the use of different types of glass, each with distinct properties and production methods (1).

As a result of their investigation, the researchers concluded that the de Burgo-O'Malley chalice had retained its original condition, including its original gilding and enamels. On the other hand, the Ó Learghusa and TP-IEP chalices appeared to have undergone refurbishment, with the latter showing evidence of later modifications to its decorative elements (1).

The research conducted by Daniela Iacopino and her team at the Tyndall National Institute represents a significant advancement in the field of heritage science. By employing XRF technology, they have opened new avenues for exploring and understanding the complex interplay of materials and techniques used by medieval artisans (1). This study not only enhances our knowledge of Irish medieval chalices, but it also reinforces the value of using XRF for analyzing historical artifacts.

References

(1) Biolcati, V.; McDonnell, R. K.; Hoffman, A. G.; et al. X-ray Fluorescence Analysis of Three Late Medieval Silver Chalices Associated with Ireland. Herit. Sci. 2024, 12, 130. DOI: 10.1186/s40494-024-01240-2

(2) Hroncich, C. Analyzing Puebla Ceramics Using X-Ray Fluorescence. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/analyzing-puebla-ceramics-using-x-ray-fluorescence (accessed 2024-06-30).

(3) Tague, Jr., T. J.; Hall, G.; Kelly, N. A Different Kind of Art Analysis. Spectroscopy 2022, 37 (9), 16–23. DOI: 10.56530/spectroscopy.he8774f8