Posted by Carmen_Ting on July 01, 2020

Dr. Chris Vyhnal sat down remotely with SAS associate editor Roxanne Radpour to discuss how archaeological science can play an important role in teaching chemistry and experimental science to high school students. Vyhnal, the Science Department Chair at the Thacher School in Ojai, California, designed a 4-day course titled “Chemical Synthesis of Color in Art” for his students when he and the rest of his colleagues at Thacher were tasked to produce an emergency last minute short course in the 2017-2018 academic school year.

RR: “You chose to do ‘Chemical Synthesis of Color in Art’. Where did that inspiration come from?”

CV: “Well in part it was fueled by our move beyond APs… and I had just recently been to the ChemEd conference in Brooking, South Dakota, which is a major conference for chemical educators at the high school and college level and I had heard a talk from Mary Virginia Orna, who teaches at the College of New Rochelle, and she spoke on historic mineral pigments in general and Egyptian Blue in particular.

CV: “I just found that talk to be fascinating. A really compelling narrative. Here’s the first evidence of intentional chemical synthesis by humans and it was done not to make something functional but to make something beautiful and I just found that to be a really interesting story that I thought would resonate with my students.

CV: “It certainly resonated with me as a geologist and geochemist because the reaction’s a solid state reaction. It had me remembering my optical microscopy and solid state chemical reactions … Then I got the idea in my head that I could do this class and have the kids synthesize some pigments with the goal of trying to see if this idea would work as part of a bigger unit of what would eventually become a longer advanced chemistry class centered on chemical synthesis in art and archaeology and applications in materials science and principles.”

RR: “You feel that archaeological pigments and ancient materials can actually play a big role in teaching chemistry topics in the classroom and really advance their learning?”

CV: “It provides an overarching theme for their study of chemical topics and principles. Rather than studying chemistry as an end in and of itself … As teachers we’re always trying to find footholds for the kids to grab onto something that hopefully resonates with them in a way and engages their emotions so that it empowers them to really want to be interested to learn what it is they’re supposed to.

CV: “I think the human element in archaeology, anthropology, art… this theme will engage kids who might not have seen themselves as science/math students … Hopefully there’s something there for everybody to grab onto.”

The short course was held in both 2018 and 2019, and Vyhnal sought out various resources for its design and implementation, starting with Pigments Through the Ages website for recipes, which he tested and modified to make ready for the students, as well as reaching out to Professor Ioanna Kakoulli at the University of California, Los Angeles (UCLA) for insight on pigment selection and materials testing using her laboratory’s resources.

Vyhnal selected Egyptian blue, madder lake, cobalt green, cobalt yellow, carbon black, and barium sulfate for the students to work with during the short course. His reasoning for these pigments centered around the fact that they “provided some varied reaction types and different synthesis protocols so the kids were getting a lot of exposure to various types of chemical reactions and how you actually put these things together in a laboratory setting”. It also broadened the color palette the students would eventually paint with and, of course, they were responsible for mixing their pigments with binders to make the paint.

Vyhnal pointed out that the many of the students had different chemistry backgrounds - some were freshman students who had never even seen a beaker. So that preliminary exposure in the short course was important. However, he was ambitious with his goals: “I wanted to have them collect some gravimetric data for two reasons: one, for their own education, but two, I had in the back of my mind we would be working this up for publication and I wanted that quantitative data to be included into the paper, so the kids collected gravimetric data on all four synthesis reactions.”

With their produced pigments, the students created artworks, one of which was subsequently imaged with forensic photography with the help of Professor Kakoulli’s group at UCLA.

Vyhnal talked about his course preparation, testing and tweaking recipes, and making sure the process was accessible to students in a short time frame. Vyhnal and Radpour also discussed the course’s development over two years.

RR: “What were the students’ responses to the course? Were they apathetic or were they excited?”

CV: “It was really positive… the comments we got back on the short course both years were really enthusiastic and supportive and positive … I was really surprised that we could take kids covering the full range of chemistry experience… freshmen who’d never had any chemistry at all working alongside senior students who had taken two years of chemistry including AP… they all came away from that experience satisfied that they learned something interesting.”

The data collected from the short course and how its design and implementation can be transformed into a year-long course was published in the Journal of Chemical Education in March 2020*. Vyhnal says that though the paper has only been out a short while, he’s received positive feedback and interest from others to incorporate similar approaches into their classroom.

RR: “I’m really curious if you can tell us more about the year-long course. Are you planning on implementing this in this upcoming academic year?”

CV: “Yes, it’s ready to go this fall!”

RR: “I’m guessing this course won’t be just pigments. I’m sure you have a wide variety of topics included in this course.”

CV: “The class is basically on chemistry applications in art and archaeology … The whole first trimester is going to be on paintings, pigments, binders, and their analysis. Then I’m going to segue into the 2nd trimester which is all going to be on archaeological materials… I’ve got a short unit on pottery and ceramics, another one on metallic artifacts, and a third on glasses, and those are all going to incorporate archaeological case studies, chemical archaeometry of those artifacts. And then in the spring term we transition to a short unit on methods of chemical analysis, quantitative spectroscopy… which they will have read about in the case studies leading up to that.

CV: “Then we’re going to transition to chemistry of conservation and restoration from a conservator’s perspective, and the last [unit] is on forgery detection and provenance establishment. So we’ll use the chemistry of how we analyze those objects to determine if they’re authentic.”

Vyhnal is on sabbatical and currently in Cyprus, and has experienced some ups and downs from both visa administrative issues as well as attempting to do research abroad when the Covid-19 pandemic hit. When asked what it has been like managing this, especially with his whole family abroad with him, he laughed.

“It has been a wild ride. If you had told me ahead of time what our sabbatical was going to look like, I’m not sure I would have pursued it. Each tweak we’ve tried to make with a positive attitude and it’s just what we’ve got to do next!”

The full interview is in the video. Here's the link:


Editor’s notes:

The scientist at the Getty Conservation Institute mentioned at 35:58 is Giacomo Chiari, previous Chief Scientist at the GCI.

*Vyhnal, Christopher R., et al. "Pigment Synthesis and Analysis of Color in Art: An Example of Applied Science for High School and College Chemistry Students." Journal of Chemical Education 97.5 (2020): 1272-1282.