| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Scientific Methods in Art, Archeology, and Art Conservation Science
|
| Presentation Title |
The Egyptian Blues, Part 2: Quantitative Color Measurements |
| Author(s) |
Ed Vicenzi, Thomas Lam, Lisa Haney, Julia Esakoff, John Bussey, M. C. Dixon Wilkins, Sam Karcher, Travis Olds, Mostafa Sherif, John McCloy |
| On-Site Speaker (Planned) |
John McCloy |
| Abstract Scope |
Scientific investigation of Egyptian blue (EB) pigment is motivated by understanding material technology and conserving artifacts, and recently for its interesting and potentially useful optical properties. In this work, we made quantitative visible/near-infrared reflectance measurements on 12 synthesized EB samples, an artifact from the Carnegie, and 7 synthetic color standards. These measurements were deconstructed into their CIELAB color coordinates and compared to phases from X-ray diffraction. High fractions of cuprorivaite result in a lower b* (blue) and higher a* (red), whereas higher values of residual crystalline silica resulted in lower a* (green). Measured color values are found to be strongly affected by phase fractions, pigment particle size, and substrate white balance, particularly evident on the artifacts. Since EB artifacts are always heterogeneous, as are the materials produced in this study, heritage conservation efforts could use these recipes for color matching. |