New Form of Ice Discovered

Water Ice, like many other elements, can produce a variety of solid solids depending on temperature and pressure. For example, carbon can form diamond or graphite under certain conditions. Water, on the other hand, is unique in this regard, as scientists have identified at least 20 solid types of Ice.

Zach Grande pioneered a new method for measuring the properties of water under high pressure. The sample was first squeezed between the tips of two opposite-facing diamonds — freezing into several jumbled Ice crystals. The was then subjected to a laser-heating technique that temporarily melted it before it quickly reformed into a powder-like collection of tiny crystals.

By incrementally raising the pressure and periodically blasting it with the laser beam, the physicists observed the transition from cubic Ice VII to a structure of tetragonal symmetry, VIIt. They also showed that the transition to X, when water stiffens aggressively, occurs at much lower pressures than previously thought.

The study was published in the journal Physical Review B. Ice VIIt could exist in abundance in the crust and upper mantle of expected water-rich planets outside of our Solar System, meaning they could have conditions habitable for life.