January 4, 2012
Researchers Say Quasicrystals Come From Space
According to a new study, crystals found in Russia's Koryak mountains two years ago may have come from space.
Quasicrystals had only been created in the lab before geologists found them in rocks in Russia. These crystals are unusual and were first described in the 1980s by Israeli research Daniel Shechtman.Quasicrystals break rules of symmetry that apply to conventional crystalline structures, and they also exhibit different physical and electrical properties.
Luca Bindi from the University of Florence, Italy and colleagues reported in 2009 that they found quasicrystals in mineral samples from the Koryak mountains in Russia's far east.
The mineral showed that quasicrystals could form and remain stable under natural conditions.
Now, scientists wrote in the PNAS journal that the chemistry of the Russian crystals appear to have arrived in meteorites.
The researchers from Princeton University used mass spectrometry to measure different forms of the element oxygen contained in parts of the rock sample.
The pattern of oxygen isotopes was unlike any known minerals that originated on Earth, and was closer to minerals found in a type of meteorite known as carbonaceous chondrite.
The samples contained a type of silica that forms only at very high pressure, which suggest it either formed in Earth's mantle, or was formed in a high-velocity impact.
"Our evidence indicates that quasicrystals can form naturally under astrophysical conditions and remain stable over cosmic timescales," the team writes in PNAS.
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