- It is unclean.
There is a mineral hidden in the diamond, which was formed with water, says researcher Tingting Gu.
It is already known that water can be stored in the interior of the earth, but we do not know how much water is down there.
The new diamond reveals that there may be more water, in more places, and deeper down than scientists previously thought.
The mineral in the diamond can hold 10 percent water, which is a record amount.
This is what the diamond looks like Photo: Tingting Gu
Mineralized water could be from space
It happens that seawater gets stuck in minerals and accompanies them underground, but this mineral's water could just as well have come directly from outer space.
- I would very much like to study the diamond again to understand whether the water came from the sea or asteroids that struck during the birth of the earth, says Tingting Gu, who is a researcher in mineralogy.
The diamond was found in the Karowe mine in Botswana Photo: Tingting Gu
Diamond mine on the lava
The diamond is likely hundreds of millions of years old and comes from the Karowe mine in Botswana.
The mine is located in rocks with a volcanic rock known as kimberlite.
The kimberlite comes from a volcanic eruption that happened a long time ago.
The eruption must have been fast and gas-rich to force a diamond up from a depth of 660 kilometers with the mineral intact.
In a slow eruption, the mineral had instead been destroyed.
660 kilometers down is the hard lower mantle, and diamonds from it are very rare.
Tingting Gu is one of the few who has been allowed to examine the diamond.
- We can only drill just over 12 kilometers down, so the diamond is priceless to research.
It is a great privilege, she says.
The article was published in Nature Geoscience