This lesson explores billon, a copper–silver alloy widely used in coinage from antiquity to the medieval period. By examining coins from different eras, we will see how the silver content varied depending on the economic and political context, and how this variation can be studied through XRF analysis.
Objectives
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Understand the definition and characteristics of billon.
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Compare coins of different historical periods based on their silver content.
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Interpret XRF spectra to distinguish between high-, medium-, and low-silver billon.
Materials
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Selected coin samples:
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Tetradrachm of Hadrian, Alexandria (2nd century CE).
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Antoninianus of Gallienus (3rd century CE).
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Denaro picciolo of Perugia (14th century).
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Lesson Plan
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Introduce the concept of billon and its historical significance.
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Present the Hadrian tetradrachm as an example of high-silver billon.
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Discuss the Gallienus Antoninianus as a medium-silver billon coin, reflecting imperial decline.
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Examine the Perugian denaro picciolo as a low-silver billon coin of the medieval period.
To reinforce the concepts discussed here, we also provide a video lesson that visually walks through the key points of this topic. Watching the video alongside the text can help you better understand and apply these ideas in practice.
The course XRF Spectroscopy for Art Examination introduces conservators, art historians, and scientists with interest in Art to the principles and practical applications of X-ray fluorescence (XRF) spectroscopy in the examination of artworks. The course starts with basic principles of XRF and gradually explores its role in identifying materials and methods used in the creation and conservation of art.
Course Objectives
- Understand the fundamentals of XRF spectroscopy and how it applies to the analysis of art.
- Learn the key features and limitations of XRF for examining art and archaeology.
- Gain skills in interpreting XRF spectra to identify specific elements in paint layers, inks and metals.
