The unexplained faces of Belmez

https://coolinterestingstuff.com/the-mystery-of-the-belmez-faces

There's a small town in Spain called Belmez, with a small population of under 2000 people. In August of 1971 a strange occurrence appeared, in a private house owned by the Pereira family. Maria Gomez Pereira noticed an unusual stain on her kitchen floor. It was getting bigger over a period of time, but what was odd, is that the mould grew to look like a face. While the mould was growing it was said to have moved places several times. Understandably terrified by this, Pereira tried repeatedly to clean and removed the mould to no avail. She asked for assistance from her husband Juan. He came to the conclusion to pick axe at the floor, with their son then lay new cement. After a week things returned to normal but then the faces began to reappear again.

Of course Pereira wanted the face removed permanently but when local gossip reached the Mayor, he made sure they didn't destroy it. He had some investigators cut out the floor to study it. Surveyors also came to dig up the family's floor. Workmen found ten feet beneath the floor, skeletons over 700 years old and some, with no skulls. With a bit of research, it was found that the house was built above a Christian cemetery in the 1830's. Before that, it was thought to be a Muslim burial site and the Romans lain their dead.

The bodies were moved into a catholic cemetery and the holes were filled. Weeks passed and another face appeared, different than the one before. If anything it made it worse, as several faces appeared. It was said one face might appear in the morning for it to be a different a few hours later.

Word had soon spread to other countries and visitors from around the world including student, researchers, priest etc came to solve the case. A well-known paranormal investigator Dr. Hans Bender from Germany said 'without doubt the most important paranormal phenomenon this century.'

A full investigation included testing of the concrete which found no evidence of dyes or pigments being used. A German TV crew sealed off the area so no one could tamper with it for three months. They reopened the room to find the faces had moved and changed.

Theories
Some researchers hypothesized the cause is a process called thoughtgraphic, which is when an image is consciously, or subconsciously, projected onto the floor. Maria Pereira was thought to have this psychic power. This was debunked as the faces still appeared after her passing in 2004.

Luis Ruiz-Noguez hypothesized that the explanation for the faces is an oxidizing chemical. Nitric, sulfuric, muriatic or acetic acid could be used to create this effect. Another explanation might be the use of agents sensitive to light, for example silver nitrate. Which is known to darken when exposed to ultraviolet sunligh

Source
http://news.bbc.co.uk/1/hi/world/from_our_own_correspondent/476045.stm
http://www.mysterious-planet.com/belmez-faces.php![]