Scientists have stumbled upon an entirely new type of water that they are calling Ice-VII, and they believe it is being caused by diamonds deep in the crust of the Earth. The extraordinary discovery could change our understanding of fluid pockets that reside hundreds of miles below the surface of the Earth.

This new type of ice is about 1.5 times as dense as the ice we’re familiar with, which is called Ice I. It has an entirely different atomic composition, and it is similar to what is found on ice moons that would orbit planets like Jupiter or Saturn. Ice VII has an entirely different structure than Ice I, with a cubic structure rather than a hexagonal one.

While it is possible to create Ice VII on Earth with enough pressure, scientists did not think it could be found on Earth because it is too warm to even form Ice VII, and even more unlikely that it could be stable. The scientists were looking for a rare type of carbon dioxide when they made the discovery.

“The discovery of Ice-VII in the diamonds is the first known natural occurrence of the aqueous fluid from the deep mantle,” reads a statement from the University of Nevada Las Vegas. “Ice-VII had been found in prior lab testing of materials under intense pressure. Tschauner also found that while under the confines of hardened diamonds found on the surface of the planet, Ice-VII is solid. But in the mantel, it is liquid.”