The peculiar emerald hue of a centuries-old, mummified teenager has puzzled archaeologists since his discovery in Bologna, Italy back in 1987. Now, groundbreaking research published in the Journal of Cultural Heritage has finally unraveled the chemical mystery behind this extraordinary preservation phenomenon. The teenage boy's remains, discovered in a copper-alloy coffin beneath an ancient villa, represent the most complete green mummy ever documented, offering unprecedented insights into the complex interactions between burial materials and human remains.
- 1200-Year-Old Mummies of Adult and Baby Found Cocooned in Copper, Fur and Bark
- Ten Incredible Mummy Discoveries That Shocked the World
The Discovery That Changed Everything
When construction workers uncovered the burial site in the basement of a Bologna villa, they stumbled upon something truly unique. The adolescent, estimated to be between 12 and 14 years old at the time of death, lay in a fetal position inside a copper box that had cracked open at some point during the centuries. Radiocarbon dating placed his death between 1617 and 1814, during a period when elite burial practices in northern Italy often involved elaborate preservation methods.
What immediately captured researchers' attention was the corpse's striking coloration. Almost the entire skeleton glowed with various shades of emerald green, from skin to bone, with only the left leg retaining a more natural appearance. The skeleton was nearly complete except for both feet, which likely detached when the copper container broke. According to Daily Mail, the preserved skin was covered by a pale green coating similar to the patina that develops on copper and bronze statues.
The Copper Connection: A Chemical Transformation
Led by conservation scientist Annamaria Alabiso from the University of Rome Tor Vergata, the research team employed sophisticated analytical techniques including Fourier Transform Infrared spectroscopy, Raman spectroscopy, and Scanning Electron Microscopy to decode the mummification process. Their findings revealed a fascinating chemical ballet that occurred over centuries.
- Mummy of a child warrior from lost medieval civilization unearthed near Arctic
- Are You My Mummy? DNA Tests to Seek Modern Relatives of 800-year-old Mummified Boy
The copper container's antimicrobial properties initially helped preserve both hard and soft tissues by inhibiting bacterial growth. However, as the body decomposed, acidic fluids leaked from the corpse and reacted with the metal, causing it to corrode. This process generated copper corrosion products, specifically malachite and pseudomalachite, which then infiltrated the teenager's remains. Over time, copper ions systematically replaced calcium in the boy's skeleton through a process called ionic substitution, simultaneously solidifying the bone structure while tinting affected areas in distinctive emerald shades.
"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 told New Scientist. The unique preservation resulted from multiple environmental factors working in concert: low temperatures in the basement, limited oxygen availability inside the sealed container, and the biocidal action of copper ions all contributed to this extraordinary mummification.
Graphical abstract depicting the full set of remains, which had all turned green except for one leg. (Alabiso et al. /Journal of Cultural Heritage)
Why Only One Leg Remained Natural
The mystery of why the left leg escaped the green transformation offers additional clues about the preservation conditions. When the copper box cracked at its base, decomposition fluids drained away, creating a cool, dry chamber with minimal oxygen. This enhanced the preservative effects but also meant different parts of the body experienced varying exposure to copper ions. The researchers believe the left leg's position may have protected it from direct contact with the corroding copper, explaining its more natural coloration.
The teenager's feet, which are entirely absent, likely detached and were lost when the container broke. In-depth chemical and physical analysis revealed no clear signs of disease or trauma, leaving the cause of death unknown. What remains certain is that this young person received a burial befitting someone of considerable social standing, given the expense of a copper coffin, which would have cost the equivalent of approximately $260,000 in today's currency.
Implications for Archaeological Science
This discovery at the University of Bologna is far more than solving a colorful curiosity. The Bologna green mummy stands as the most complete example of copper-induced mummification ever documented, surpassing previous partial findings such as the mummified hand of a newborn baby clutching a copper coin. Understanding these preservation mechanisms helps archaeologists better interpret burial practices, social hierarchies, and post-mortem changes in ancient remains.
The find of a baby’s hand turned green, clutching a copper coin. (János Balázs/Archaeological and Anthropological Sciences)
The research team noted that while copper compounds often cause superficial green coloration on human remains, the Bologna case demonstrates how soluble copper can penetrate deeply into soft tissues and bones. The flesh and discoloration extended from the copper-stained forearm down to the bone itself, with some vertebrae, hip bones, and leg bones showing copper levels several hundred times higher than average.
"It was a very emotional experience for me to work with these unique human remains," Alabiso reflected. The teenager's story, locked in his emerald bones for centuries, now illuminates the complex chemistry of death and preservation, reminding us that even in burial, the materials we choose continue to interact with our bodies in unexpected ways.
Top image: The mummified remains of the teenager, colored green. Source: Alabiso et al. /Journal of Cultural Heritage
By Gary Manners
References
Alabiso, A. et al. 2025. The curious case of the green-colored body: A multidisciplinary investigation of a mummy preserved in a copper-rich environment. Available at: https://www.sciencedirect.com/science/article/abs/pii/S1296207425002092
Leatham, X., 2025. Unravelling the mystery of the GREEN mummy: Mummified corpse turned bright emerald after being held in a copper box, study reveals. Available at: https://www.dailymail.co.uk/sciencetech/article-15245329/mystery-GREEN-mummy-corpse-emerald-copper.html
Lesté-Lasserre, C., 2025. Boy's body was mummified and turned green by a copper coffin. Available at: https://www.newscientist.com/article/2502176-boys-body-was-mummified-and-turned-green-by-a-copper-coffin/
