Mysterious Quasicrystals May Have Fallen From Space, Study Says
A new study indicates that quasicrystals, a type of mineral once thought to be "impossible" in nature, is of extraterrestrial origin and probably around 4.5 billion years old.
Found in Russia's Koryak mountains,the quasicrystals may have fallen to Earth from space, according to a new study published this week in the Proceedings of the National Academy of Sciences.
The crystals had only been created in laboratories before geologists found them entertwined with a silica mineral that forms only at high pressures, and might have been created by a collision with chondrite body.
Scientists say that unlike conventional crystals, quasicrystals contain mathematically regular but unique units that never appear twice, unlike regular crystals which are made up of regular, repeating units.
Quasicrystals first became known to science in early 1980s when researcher Daniel Shechtman created them in his laboratory. Since then scientists replicated Schechtman's findings in labs. Two years ago, a fragment of rock from Russia's Koryak mountains which because the first example of a naturally-occuring quasicrystal.
A team of researchers carried out an analysis of the sample based on the theory that the quasicrystal is part of a meteorite that fell to Earth. According to a New Scientist report, the researchers say "the rock has experienced the extreme pressures and temperatures typical of the high-speed collisions that produce meteoroids in the asteroid belt."
In addition, the relative abundances of different oxygen isotopes in the rock matched those of other meteorites rather than the isotope levels of rocks from Earth, the report said.
The scientists added that the pattern of oxygen isotopes are typical of ancient meteorites called carnonaceous chondrites, which were formed at the birth of the Solar System, making the quasicrystal around 4.5 billion years old.
The findnigs of theoretical physicist Paul Steinhardt's study, who spent weeks tracing the origins of the world's only known natural example of a quasicrystal, was published in the Proceedings of the National Academy of Sciences.