Rare Extraterrestrial Crystal Found in Siberia is the Only Natural Quasicrystal on Earth
In a remote corner of the world, in the Koryak Mountains in Far-Eastern Siberia, scientists discovered a rare extraterrestrial crystal dating back to the birth of our solar system, 4.5 billion years ago, making it as old or even older than Earth itself. It is believed that the exotic mineral came to Earth on a meteorite.
An international team of researchers led by Princeton University scientists analysed the crystal and discovered that it has an extremely unique composition, so unusual in fact that it was thought impossible to exist. Although the crystal looks quite normal on the outside, the inner structure is unlike anything found on Earth, making it the world’s only known sample of naturally occurring quasicrystal .
A quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry. Instead of the regularly repeating clusters of atoms, quasicrystals contain more intricate atomic arrangements.
Until now, experts believed that quasicrystals could only be formed under laboratory conditions. However, the latest discovery in Siberia has turned this notion on its head. "The finding is important evidence that quasicrystals can form in nature under astrophysical conditions, and provides evidence that this phase of matter can remain stable over billions of years," said physicist Paul Steinhardt, the Albert Einstein Professor in Science at Princeton.
To uncover the origin of the natural quasicrystal sample, the team of scientists tested numerous possibilities, including the chance that the sample was actually a byproduct of industrial manufacturing. However, their analyses showed that the crystal was embedded in stishovite, a mineral found in meteorites, indicating that the quasicrystal and stishovite formed together through a natural high-pressure process.
The team of investigators then examined the rations of different isotopes of oxygen which vary according to whether the minerals formed on Earth or in space. The results clearly revealed that the ratio of oxygen isotopes is indicative of formation in space.
By John Black