Independent Research: Where Chemistry and Art History Come Together

Today’s post comes from Julie MacDonald, class of 2012 and Art Center Student Docent.

While you may think of the Art Center as a place for quiet reflection or personal exploration, it is also a thriving educational center for Vassar students as well as the surrounding community. As a student docent I am frequently in contact with school groups and other visitors seeking to learn more about what hangs on our walls, and, as any student of art history can attest, Vassar professors frequently include objects in the collection in their syllabi.
 
However, investigation of the collection continues beyond the gallery visits, daily tours, and lectures. One of the most exciting features of a museum at an educational institution is the access available to objects not on view. Just because an object is not on display does not mean one must wait patiently to see it; researchers from the student body, the faculty, or general public can make an appointment to view objects in collection storage. This accessibility also makes the Art Center a welcoming and encouraging place to conduct independent research, and for the past semester I have been lucky enough to take full advantage of the opportunity.
 
What started as a conversation with art professor Eve D’Ambra about my interests with regard to Art History, due in part to my unusual presence in Taylor Hall as a Biology major, led to working as part of an interdisciplinary team investigating the elemental composition of the cartonnage covering a Ptolemaic mummy, Shep-en-min, in the collection of the Art Center. Under the guiding influence of Diane Butler, I worked not only with Professor D’Ambra to investigate the cartonnage as an art object, but also with chemistry professor Joseph Tanski to use a technique called X-ray fluorescence (XRF) spectroscopy. XRF allows you to analyze the elemental composition of an object without having to take a sample, thus making the procedure completely non-invasive. This is particularly important in research involving mummies—while the cartonnage, a plaster and paint covering placed over the wrappings of a mummy, may be considered an art object, it is important to remember the humanity of Shep-en-min himself.
 
Using this technique it was determined that the paints used in creating the highly detailed and colorful cartonnage are inorganic, derived from minerals rather than organic materials. The major components of the pigments include hematite, calcite, and gold. However, the pigment known as Egyptian blue, present in three shades on Shep-en-min’s cartonnage, was the most culturally valued pigment. Consisting of several component minerals that had to be ground and heated in a precise way, Egyptian blue was the most complex pigment to manufacture, especially when one integral mineral, malachite, may have been imported from as far as the Sinai peninsula, almost 500 miles away from Shep-en-min’s place of burial at Akhmim.
 
Detailed examination of the components of these pigments makes it evident that these materials were meticulously prepared, which allows the modern investigator to understand the importance of religious practices, like mummification, to the ancient Egyptian.