Archaeometry: Unveiling the Past with Future-Ready Tools

Thought LeadersMary Kate DonaisProfessor of ChemistrySaint Anselm College

In this interview, Mary Kate Donais discusses the portable analytical devices used to uncover the secrets of the past.

Can you tell us about how you came to work in archaeometry?

I arrived at this opportunity in a rather unexpected way. A faculty member who specializes in Latin and Greek in the Classics department where I teach reached out to me about incorporating chemistry into an introduction to archaeology course that he teaches. As an analytical chemist, I am always looking for opportunities to collaborate with others, and I make it known to my colleagues that such opportunities exist.

We began by designing a lab opportunity for students to come to our science building, and from there, we started considering how my work as a chemist could contribute to the College's archaeology program. My colleague suggested I attend College's field school to see if we could collect samples. That is when my analytical chemistry background started guiding my thinking. While bringing samples back was useful, taking an analyzer to the site could be even more beneficial.

What began as a one-summer experiment to see how it would go has now turned into multiple field school research trips. Everything just developed from there.

Can you describe archaeometry, what it entails, and the types of technologies you use? 

Archaeometry is a broad term. While the name suggests a connection to archaeology, it generally refers to cultural heritage analysis. The "metry" part of the word refers to measurement.

Archaeometry can include the analysis of objects in museums, not just those found at archaeological sites. It broadly encompasses the characterization and analysis of samples with cultural heritage significance.

We use spectroscopy and spectrometers in our work. The timing of my collaboration in this field was exceptionally fortunate because it coincided with the increasing availability of portable spectroscopy instruments, which is my primary focus. More broadly, portable instruments were becoming more advanced at that time.

Being at a small school with a limited budget for equipment, these portable devices provided an opportunity that might not have been otherwise available. While they are more straightforward and not identical to larger benchtop instruments, they often come at a lower price point, making them more accessible.

This allowed us to integrate techniques into our research that our students might not have had access to otherwise. Of course, taking an instrument to a sample—especially when that sample is in a place like Italy—adds an extra level of excitement to the work.

Another aspect of this research is that some artifacts may be too large to move, while others are too valuable to be taken out of a museum setting. In those cases, bringing the instrument to the sample is the best solution.

Image Credit: Anton Chalakov/Shutterstock.com

Many of these techniques are non-destructive. That is essential because it allows us to collect valuable information without causing any damage or detrimental impact on the artifact. We can analyze a unique object, gather the data we need, and bring that data back with us for further study, all while preserving the integrity of the sample.

Do you typically use more than one device at a time in your research? 

In my most recent work, we brought two portable devices. One is a portable X-ray fluorescence spectrometer, which is an elemental technique that provides information on specific elements present at detectable levels in a sample.

We also started incorporating a portable colorimeter, which analyzes the visible spectrum. This is another form of spectroscopy that allows us to objectively assess these objects' color. Many of them are visually stunning, so adding this new dimension helps us better understand their appearance in a more precise and less subjective way.

Are the samples you analyze primarily pottery and ceramics? 

The field school where I have done most of my work has allowed me to analyze a variety of objects. This has allowed me to learn about many new materials as an educator.

We started with construction materials and analyzed them in situ at the excavation site. These included mortars and cements, though I have also examined more contemporary plasters. From there, we moved on to glass, specifically small square tesserae used in mosaics. This opened up new questions, including how the glass was produced and what elements created different colors. These were especially exciting to study because, unlike mortars, which resemble cement, the tesserae are visually striking with their wide range of colors.

We have also worked on ceramics. Our most recent research involved analyzing weaving tools, which are fired ceramic shapes. Another fascinating material we have studied is fresco, which, like the tesserae, features vibrant colors. Each object is unique, and we are committed to analyzing it using non-destructive methods.

Can you tell us more about the weaving tools? Do these tools provide insight into the history of women and manufacturing? 

My most recent collaboration in Italy focuses on specific weaving tools used by the Etruscans. While weaving is a practice found across all cultures and regions, these particular tools belonged to the Etruscans, a civilization later conquered by the Romans. The artifacts date back to the 5^th to 8^th century BCE.

The site where we conducted this research had significant evidence of weaving activity. We have a general understanding of their weaving process, which involved wall looms—large wooden frames leaned against a wall.

Loom weights, which were ceramic, were used to hold the vertical strands of yarn or thread under tension, allowing the weaver to pass horizontal threads or yarns through them with a shuttle. We have collected and analyzed many of these loom weights from a specific archaeological site where I have collaborated with archaeologists.

We analyzed approximately 600 spindle whorls, which were used to spin fibers into threads or yarns, which were then used for weaving. They are shaped somewhat like a spinning top but have a hole through the center where a spindle—a thin stick—is inserted. When spun, the whorl twists fibers such as cotton or wool into either a heavier yarn, if the spindle is larger, or a fine thread, if the spindle is smaller and lighter.

By analyzing these artifacts chemically and considering their physical characteristics, such as color, we can better understand women’s roles in Etruscan society.

Spindles found in residential areas suggest weaving for household and utilitarian purposes, while those discovered in religious or votive spaces may indicate weaving for ritualistic or ceremonial use. Connecting the chemistry of these objects with their physical attributes helps us uncover more about their cultural significance.

What did your analysis reveal in this particular case? 

We are still in the early stages of analyzing the chemical data. However, we know that the spindle whorls were excavated in concentrated areas of the site, indicating their association with specific purposes. We are still determining whether chemistry and color are linked to those findings.

We have observed a range of colors among the spindle whorls, including yellow and brown, red, black, and gray. Our next step is to analyze whether specific colors correlate with excavation areas and whether we can establish a connection between chemistry and location.

Preliminary results suggest that there is not a significant amount of chemical variation among the spindle whorls, meaning we cannot yet definitively link certain chemical compositions to specific areas. However, we have identified a few outliers, which may indicate that those spindle whorls were produced in different geographic locations and later imported. This could provide insight into migration patterns and trade networks within Etruscan society.

The Cataract House hotel is a fascinating example of your work. Could you explain what the Cataract House was like, its historical significance, and your analysis of its building materials? 

This was a particularly unique opportunity where I could collaborate on a project that did not require traveling internationally with equipment. Instead, we were able to transport the instruments by car to Niagara, New York.

The Cataract House was a hotel located on the border between the United States and Canada. Historical records indicate that it played a crucial role in the Underground Railroad, helping enslaved individuals escape to freedom in Canada. The kitchen staff were known to have been instrumental in this effort. Unfortunately, the Cataract House burned down, and today its remains are buried beneath a park near the falls.

The University of Buffalo has conducted multiple excavations of the site's ruins. We were invited to assist with a recent excavation using our portable X-ray fluorescence (XRF) analyzer. We later conducted follow-up analyses in our laboratory using portable laser-induced breakdown spectroscopy (LIBS). Given its historical significance, the goal of the work was to help pinpoint the location of the kitchen.

The excavation involved digging several trenches to explore the hotel's multiple construction expansions. By analyzing plasters from different areas of the site, we were able to help establish distinct construction phases. We are confident that we successfully identified the location of the kitchen, allowing us to stand in the very space where these remarkable efforts to aid enslaved individuals took place.

Why are you so confident in your findings? What technology did you use, and what results led to your conclusion? 

We analyzed plasters from three trench areas; two had very similar elemental characteristics. Based on this data, we are confident that those sections were constructed during the same period. However, the plaster from the suspected kitchen area showed distinct elemental differences, indicating that it was built in a different, likely older, time period.

The combination of this chronological distinction, along with the room’s dimensions aligning with historical maps of the hotel, strongly supports our conclusion. These factors together provided a high level of confidence that we had correctly identified the location of the kitchen.

I understand you have also worked on Roman walls. Can you tell me more about that research? 

Much of this work has been conducted at a site that has been in use for a long time, leading to multiple layers of construction. Often, new structures were built on top of older ones, resulting in walls that do not always align in an immediately clear way. In some cases, one wall must be deconstructed to analyze the one beneath it or to understand how the structures fit into the overall layout of rooms or terraces, which was a focus of our latest research.

Because mortar is a man-made material, and its components are often geographically specific—such as clays sourced locally—builders would have followed a consistent recipe when producing it. By analyzing the elemental composition of the mortar using X-ray fluorescence (XRF) and laser-induced breakdown spectroscopy (LIBS), we can identify a sort of elemental fingerprint. This allows us to compare different mortars across various walls to determine whether they were likely constructed during the same period.

This analysis determined that three terrace walls were likely built at the same time, as their mortars had very similar chemical compositions. However, a fourth wall at the bottom of the hill showed distinct elemental differences, suggesting it was constructed later. Based on the overall arrangement, this last L-shaped section was probably an addition, possibly intended to enhance the function of the existing structures.

You have used portable devices in all your research work. What do you think is next for portable technology in this field? 

These devices are continuously becoming smaller and more affordable. One of the newer techniques still being developed, particularly in certain countries for cultural heritage applications, is portable LIBS—laser-induced breakdown spectroscopy. It is semi-disruptive, as it creates a tiny hole, but the instrument can be set so that the naked eye cannot detect where it was used.

However, there is still some concern about ensuring no damage is caused, particularly from the archaeology side. A key challenge is improving communication with archaeologists to reassure them that LIBS can be used without harming artifacts and that the information gained is valuable enough to justify trying new methods.

Beyond that, there is potential for even more advanced portable technologies, such as a truly portable, small, and affordable mass spectrometer. Another exciting development would be to make these instruments more accessible to researchers without extensive scientific training, allowing them to obtain accurate and precise data more easily. Techniques that were more complex or inaccessible 10 or 15 years ago are becoming more user-friendly, which will continue to advance the field.

We are here at Pittcon. How important is Pittcon for facilitating discussions that could advance this field? 

Pittcon has been incredibly valuable for me. The session I organized on the first day was instrumental in connecting me with colleagues, both the speakers and other attendees presenting in different sessions.

We have had fantastic discussions about standard materials, as well as instruments that I did not realize others were also using. For example, I thought I was unique in using a particular colorimeter for archaeometry, but others have already started integrating it into their research.

Pittcon is a great space for bringing together people from different backgrounds, whether from academia, government labs, or industry, who are working on cultural heritage research. I have not had a chance to walk the exhibit floor yet, but I look forward to seeing what other companies offer. There could be instruments I have not considered useful, whether for portable analysis or lab-based research.

How important is it for students to come to Pittcon and experience the show? 

It is very important for students to attend conferences, especially at an international conference like Pittcon. For me, this is in my backyard, so I am excited to bring students here for their first conference experience. And what a first experience—to be at a major event like this, where they can walk the exhibit floor, meet scientists, and see instruments they have only read about in textbooks.

It is also great for them to connect names they recognize from research articles or class discussions with real people. It helps make what they are learning feel more tangible and practical. It is not just theory in a book; it is something they will use when they go to graduate school or to work in industry. Maybe they will meet someone here who could help them land a job.

We have spoken a lot about the past, but what does the future hold for you? 

I plan to continue in this exciting field and look forward to working with new collaborators. It is always fascinating to see where those partnerships lead.

I have also taken on a new role this year—I started in January as the Editor-in-Chief for Applied Spectroscopy Practica, a sister journal to Applied Spectroscopy published by the Society for Applied Spectroscopy.

This is a new challenge for me outside of my work as a college professor. I am excited to learn more about the academic publishing industry, especially peer-reviewed publications. Over the next few years, I hope to help Practica grow and evolve, making it an even more valuable resource for the spectroscopy community.

About Mary Kate Donais

​Dr. Mary Kate Donais is a Professor of Chemistry at Saint Anselm College, specializing in analytical chemistry with a focus on applying spectroscopic techniques to archaeological and cultural heritage materials. She earned her B.S. in Chemistry from Bucknell University in 1991 and her Ph.D. in Analytical Chemistry from the University of Massachusetts in 1996. Dr. Donais has been recognized as a Fellow of the Society for Applied Spectroscopy (2014) and the Royal Society of Chemistry (2017). She served as the Barbara J. Stahl Fellow in Science and the Humanities from 2022 to 2025. 

This information has been sourced, reviewed and adapted from materials provided by Pittcon.

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