Silver has been one of the most important metals in coinage throughout history. However, pure silver is too soft for practical use, so it is typically alloyed with other metals, primarily copper. This lesson explores how silver-copper alloys have been used in coins from ancient Rome to contemporary Italy, examining their composition and spectral characteristics.
Objectives
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Recognize different silver alloys used in historical coinage.
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Interpret XRF spectra to identify variations in silver and copper content.
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Compare compositional differences among coins from different periods.
Materials
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Silver 925 standard sample
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Silver 835 standard coin (500 Lire Centenario)
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Roman Denarius coin
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Medieval Denier coin (Lucca, 12th century)
Lesson Plan
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Introduce the concept of silver-copper alloys and why pure silver is unsuitable for coinage.
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Present the two silver standards (925 and 835) and discuss their compositions.
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Analyze the XRF spectra of both standards, identifying the silver and copper peaks.
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Examine and compare spectra of the Denarius and Denier coins, noting changes in alloy composition and the appearance of lead in the medieval coin.
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.
