Researchers find ‘impossible’ crystal in a meteorite: It features a symmetry not seen naturally
It’s as if the crystal was created artificially. The crystal features a kind of symmetry not seen naturally, called icosahedral symmetry. The crystal originated in space. Experts say the crystal has exceptional resistance characteristics.
Experts have come across a fascinating, unusual type of crystal, long believed impossible to exist, in a piece of meteorite in Siberia, Russia.
The crystal has an unusual, repeating structure. Experts believe that the so-called quasicrystals could have only been made artificially. However, the discovery which was detailed in a new study marks the third discovery of the bizarre material in what is believed to be a natural form.
The research was published in Scientific Reports. The object was analyzed by scientists at the University of Florence, Caltech and Princeton.
Experts found the tiny sample –just a few micrometers wide— after studying the meteorite which crashed in Siberia with electron microscopy. Experts concluded that the quasicrystal features a kind of symmetry not seen naturally before, called icosahedral symmetry.
The crystal offers 60 points or rotational symmetry composed of aluminum copper and iron.
‘Quasicrystals’ are short for quasi-periodic crystals. They defy the symmetrical rules that define crystals – they are ordered, but not periodic.
Co-author Paul Steinhardt from Princeton University told Motherboard;
“What is encouraging is that we have already found three different types of quasicrystals in the same meteorite, and this new one has a chemical composition that has never been seen for a quasicrystal. If you want to cover your bathroom floor, your tiles can be rectangles or triangles or squares or hexagons,’ said Patricia Thiel, a chemistry and materials science expert at Iowa State University.”
“Any other simple shape won’t work, because it will leave a gap. In a quasicrystal, imagine atoms are at the points of the objects you’re using.”
The first naturally occurring quasicrystals were discovered in the early 2000’s after experts tried manufacturing them for years.
As detailed on Princeton.edu, quasicrystals are solid minerals that look quite normal on the outside, their inner structure makes them fascinating to scientists. Instead of the regularly repeating clusters of atoms seen in most crystals, quasicrystals contain a more subtle and intricate atomic arrangement involving two or more repeating clusters. As a result, a quasicrystal’s atoms can be arranged in ways that are not commonly found in crystals, such as the shape of a 20-sided icosahedron with the symmetry of a soccer ball.
“Quasicrystals are a peculiar form of solid in which atoms are set in a non-periodic structure,” said Dr. Bindi, who led the study.
“Up until a few years ago it was thought that these compounds could only be artificial,” Dr. Bindi said.
Experts from Caltech discovered earliers this year a mechanism how quasycrystals form in space. Professor Paul Asimow believes that Tte ‘impossible’ structure may have been created through a cycle of compression, heating, decompression and cooling.
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