December News from the Conservation Lab — X-Rays and Electron Beams!

By Caroline Roberts, Conservator

As an archaeological conservator I know that, sometimes, you need to travel to where the work is. This was on my mind last month when I found myself flying back and forth across central campus, between our lab at the Kelsey Museum and the Electron Microbeam Analysis Laboratory (or EMAL). EMAL is a shared access research space within the Earth and Environmental Science Department, and it’s home to a range of instruments used for materials analysis.

I had a clear mission: to identify the composition of modern architectural limes and mortars from Sudan. Suzanne acquired the samples during the 2019 El-Kurru field season, with the goal of determining whether they were safe for use in architectural conservation at the two Sudanese archaeological sites where a Kelsey team is working.

I used x-ray diffraction and scanning electron microscopy to identify the unknown materials, processes that involve careful sample preparation, instrument setup, and data interpretation. It was time well spent since we now know that some of these materials contain gypsum, which poses risks to archaeological stone. This kind of information is crucial for informed conservation decision-making in the field, and will help shape architectural treatment and preservation plans for the El-Kurru and Gebel Barkal heritage sites.

A large machine
Samples loaded into the Rigaku x-ray diffractometer.
Woman standing next to and looking into a large machine
Not-so-patiently awaiting XRD results!