It's been centuries since a small, unassuming portrait was seen in its original detail.
Thanks to a multi-disciplinary network of archaeologists, art historians, and chemists, the nameless woman's image can be seen more clearly.
Found in the small town of Herculaneum was a small, circular image of a woman's face. Her portrait was found to the right of a door that opened into a network of rooms. Herculaneum suffered a fate similar to that of Pompeii when life was brought to a standstill when Mount Vesuvius erupted in 79 A.D. Until the early 20th century the house that contained the painting had been hidden by soot and ash. Ironically, the excavations that began 70 years ago may have begun the painting's decline, exposing it to changes in temperature, humidity, and human interference.
See a 360 view of the room here.
Presenting their findings at the 254th National Meeting and Exposition of the American Chemical Society, the researchers explained how they were able to see restoa delicate artifact. (This artist has made x-rays his medium.)
The effort was led by Eleonora Del Federico, a professor of chemistry at the Pratt Institute. Using a portable tool called Elio developed by XGLab, Del Federico and her team were able to scan the painting with macro X-ray fluorescence. Selecting one atom at a time, the data revealed maps of chemical compounds such as iron, lead, and copper. Lead, for example, indicates the presence of red compounds, while copper often indicates the presence of blue or green.
Speaking at an ACS press conference, Del Federico explained that certain colors have been misrepresented in paintings. For example iron-based yellow pigment will turn red from heat, and reconstructions have been made with incorrect colors. Chemists are now able to get a more exact picture of how Herculaneum and its artifacts must have looked in their own time.
"By unraveling the details of wall paintings that are no longer visible to the naked eye, we are in essence bringing these ancient people back to life," Del Federico said in a press release. She believes that by learning about the quality and sophistication of a painting, characteristics such as the aspects of social life could be revealed.
X-rays have been used to reveal hidden images in famous artworks before. In 2015, X-rays revealed a hidden figure in Rembrandt's An Old Man in Military Costume. Pablo Picasso's paintings have also yielded their secrets to x-ray machines. Scans of the abstract painter's famous pieces revealed he sometimes used common house paints, rather than more pricey art oils, making him one of the first artists to do so.
Del Federico's machine, however, is the first of its kind to be easily transported, meaning it can easily make its way down tattered, ancient roads.
Her work was done in partnership with the Herculaneum Conservation Project, which will use these chemical maps to choose safe conservation methods to clean and restore the painting.
When asked during a press conference how many ancient paintings could be uncovered using this technique, Del Federico answered emphatically—"countless."
Correction: A previous version of this article stated that lead indicates the presence of white paint. Lead indicates the presence of red paint.