The mummified remains of a teenage boy, turned entirely green by a copper burial box, have been analyzed in Italy. Buried around three centuries ago in Bologna, the discovery provides new insights into copper's preservative effects on human tissue. The boy, aged 12 to 14, is the only near-complete green mummy known.
In 1987, the mummified body of an adolescent boy was discovered in the basement of an ancient villa in Bologna, northern Italy. Forensic analysis at the University of Bologna determined it belonged to a boy aged 12 to 14. Since then, the remains—complete except for the feet—have been stored at the university.
A multidisciplinary team, including geneticists, anthropologists, radiologists, mathematicians, physicists, and computer scientists, recently investigated the mummy. Annamaria Alabiso, a conservation scientist at the University of Rome Tor Vergata, was part of the effort. “It was a very remarkable multidisciplinary collaboration,” she says.
Radiocarbon dating places the boy's death between 1617 and 1814, with no clear signs of trauma or disease. The body was buried in a copper box, which preserved both hard and soft tissues due to copper's antimicrobial properties. However, acids leaking from the decomposing body reacted with the copper, corroding the box and producing copper ions that replaced calcium in the skeleton, tinting it green from skin to bone—except for the left leg.
The skin developed a crusty patina, the pale-green coating seen on copper statues, from reactions with water and carbon dioxide. “This completely changes our point of view on the role of heavy metals, as their effects on preservation are more complex than we might expect,” Alabiso says.
The box's bottom eventually cracked, possibly from the acids, spilling liquid and leaving the body in a cool, dry, low-oxygen chamber that slowed decomposition. The feet may have detached and been lost during this process. “It was just a very emotional experience for me to work with these unique human remains,” Alabiso adds.
Giulia Gallo at the Collège de France in Paris reviewed the findings and called them “incredible” and “so beautiful.” She praised the research for substantiating the chemical processes behind the mummification and coloration.