Gold in art is mainly used for gilding. However, fake gilding materials, often made from cheaper metals, are commonly used. This lesson explores methods to identify real gold in gilding and differentiate it from imitations, focusing on the spectral characteristics of gold and common substitutes like copper and zinc.
Objectives:
- Identify genuine gold gilding based on spectral analysis.
- Differentiate fake gold gilding made from copper and zinc alloys.
- Analyze real-world examples to reinforce identification techniques.
Materials:
- Genuine gold leaf for reference.
- Sample of fake gold leaf made of copper and zinc.
- Manuscript with gilding for analysis.
- Modern panel painting with gilding.
Lesson Plan:
- Introduction to Gold in Gilding:
- Highlight the use of thin gold leaf and its application in decorative arts.
- Spectral Characteristics of Gold:
- Examine the L Alpha, L Beta, and L Gamma lines of gold and their expected intensity in genuine gilding.
- Identifying Real Gold:
- Analyze the spectrum of a balled-up gold leaf and compare it to a thin gold leaf to demonstrate expected spectral counts.
- Differentiating Fake Gold:
- Study the spectrum of a copper-zinc alloy used as a fake gilding material.
- Case Studies:
- Analyze a manuscript with gilding, identifying the spectral signature of fake gold.
- Examine a modern panel painting replica and observe variations in copper-to-zinc ratios in its fake gilding.
