Geologists recently unearthed a diamond that contained a mineral that had never been seen before on the Earth's surface, as it becomes unstable above a depth of 650 km (400 miles). Amazingly, the discovery was merely accidental, as Ice VII was found while the scientists were looking for evidence of carbon dioxide.
Accidental discoveries are by no means a super rare occurrence in science, and it drives home how much there is left to discover about the world around us. While most diamonds are formed at a depth of about 150 to 200 km, this one possibly formed at a depth of at least 700 km, notes the report.
In normal ice, known as ice-I, the oxygen atoms arrange themselves in a hexagonal shape.
There are actually multiple forms of water ice that form under different pressures and temperature conditions, and this new form of ice is far from the only different setup we've discovered thus far.
Thanks to their discovery, ice-VII has been recognized for the first time as a mineral by the International Mineralogical Association.
When a solid form of matter is subjected to more and more pressure, the space between the chemical bonds generally starts to decrease and the bonds tilt towards each other. In that very specific case, ice-VII can occur.
However, this new form of ice represents a finding greater than the results of a simple increase in pressure.
Rossman said that finding ice-VII, even by accident, was a thrill for the whole team.
Some diamonds, like the ones pictured, are for people who like jewelry; others are for scientists who want to know more about the Earth's interior. However, when it comes to us knowing the structure of what lies beneath the Earth's surface it seems that we know only very little. As you'll recall, the mantle is too warm for ice-VII to exist.
Tschauner candidly admits that he and his team did not intentionally set out to look for ice-VII in diamonds.
For the first time, scientists have found Earth's fourth most abundant mineral-calcium silicate perovskite-at Earth's surface. As they're forming, they will occasionally trap pieces of the environment around them in "inclusions".
Graham Pearson was quoted in an American online magazine Inverse saying, "This was very special because this mineral had been theoretically predicted, but it was not thought possible to see it preserved at the Earth's surface for observation and measurement".
In 2014, researchers including Pearson found a diamond containing ringwoodite, the planet's fifth-most abundant mineral, which showed there is a large amount of water in the mantle, chemically bound to silicate rocks.
However, as the authors discovered, diamonds can trap small bubbles of extremely dense pressurized water when they form. They crack and whatever inclusions they had in them are lost. He explained the mineral is found deep inside Earth's mantle, at 700 kilometres.