Unusual blue spots on the thousand-year-old iceman

A strange mineral can invade cadavers, turning the body green in damp, iron-rich environments.

Vivianite mineral on a bone fragment buried in sand. Photo: Terry O'Connor.

While studying Ötzi the Iceman, the 5,000-year-old mummy of a man frozen in the Alps, scientists discovered tiny specksgreenon the skin, according toScience Alert. These strange blue crystals are actually a mineral called vivianite (or green iron ore), which forms on corpses in iron-rich environments. In the case of Ötzi the Iceman, the vivianite spots were caused by the body lying near an iron-rich rock outcrop.

According to Atlas Obscura, a man named John White was buried in a cast-iron coffin in 1861. Each coffin usually had a glass window so that relatives could see inside, even though the lid was closed during the funeral. Some time after the burial, the window broke, allowing groundwater to enter the coffin and affect the body.

More than a century later, White's coffin was exhumed due to land development plans in the area. People were shocked to find that his body had turned completely green, with large green vivianite crystals on his body and in his coffin.

Vivianite crystals are formed from the chemical reaction of phosphate with iron and water. The human body is made up of many different molecules, but phosphate is the most important in the formation of vivianite, which is found throughout the body. Phosphate is found in hard bones and teeth, and binds DNA and RNA strands together, and is used by cells to store and metabolize energy to synthesize many types of proteins..

As a dead body begins to decompose, phosphate leaks into the surrounding environment. If the environment is moist and iron-rich, like White's coffin or Ötzi the Iceman's grave, the phosphate reacts with different molecules to form the mineral vivianite.

When first formed, these crystals are colorless, but when exposed to oxygen in the air, they quickly turn green and create a strange sight.

According to VNE