10. Grooved Spheres
There is a rock in South Africa known as Precambrian which is about 2.8 billion years old. Miners, while digging up, found some mysterious metal spheres in there. They are about 1 inch in diameter and have three parallel grooves etched around its equator. Some of them are solid bluish metal with flecks of white while others are hollowed filled with a spongy white substance. The origin and reason of these spheres is unknown.
9. Placebo Effect
Placebo Effect is when a patient take fake medicine, advised by a doctor, and get better. That fake medicine works because patient expect and believe it would work. Similar effect known as Nocebo Effect when a person take fake drugs and start experiencing problems which is caused by real drugs. This phenomena proves that there is some mysterious complicated mind-body connection which we still don't know.
8. Taos Hum
The residents of small town of Taos, New Mexico, continuously heard a mysterious sound which they call as "hum". It is a low pitched voice heard in a quiet environment and sounds like a distant diesel engine. Despite many investigation, the source of this sound is still unknown.
7. Shroud of Turin
It doesn't need any introduction. It is a linen cloth bearing the image of a man who had apparently died of crucifixion. Scientist failed to explain how the image has been imprinted. After many scientific research and experiments, no one has been able to replicate this. Some Catholics claim it to be the burial shroud of Jesus Christ. It is currently held in the Cathedral of St John the Baptist in Turin, Italy.
6. Sailing Stones
The stones in Racetrack Playa slowly move across the surface without human or animal intervention. While moving, these stones also leave a track before them. Some scientist believe it happen because of heavy wind while others claim that stones as heavy as human can't move with wind so easily. Since, no one has ever filmed the stones moving, it is still amongst top unsolved mysteries.