In 1990, a strange type of blue stone was found in Sierra Leone, West Africa, by Italian geologist and archaeologist Angelo Pitoni while he was exploring a geological extract dating back to 12,000 BC.
The mysterious stone that resembles pure turquoise, similar to those found on the breastplates of Egyptian priests, soon became known as the “Blue Sky Stone” as the strange object proved to be very different from anything known by mankind.
After returning to Europe, Pitoni took the stone to the Institute of Natural Sciences in Geneva and then sent samples that were tested in research laboratories at the Universities of Rome, Utrecht, Tokyo and Freiberg, in Germany.
Tests revealed that it was not turquoise or any other gemstone that could be officially identified, nor did it match any known mineral.
At Utrecht University, the stone underwent several tests. Strong acids did not affect the stone. When heated to over 3,000 degrees Celsius, its composition was not changed and when a small piece of the stone was pulverized and viewed through a microscope, it curiously lost its color.
According to the analysis carried out, 77% of the stone is made of pure oxygen and the rest is made up of carbon, calcium, sodium and another unknown element.
Carbon dating suggested the stones are between 12,500 and 17,000 years old.
Despite countless tests at universities and laboratories, researchers have never been able to understand how the stone acquired or maintained its blue color and its coloring remains a mystery.
The Blue Sky Stone appears to have been artificially colored by an unknown, highly advanced civilization.
The natives who live in the area where the stone was found already knew about its existence because this artifact often appears in excavations in the region, which is famous for diamond mining.
According to local legend, it is believed that the Blue Sky Stones were living beings that resided in the sky and were cast to Earth by the gods as punishment for their crimes.
