A sample of a bizarre crystal once considered unnatural may have arrived on Earth 15,000 years ago, having hitched a ride on a meteorite, a new study suggests.
The research strengthens the evidence that this strange "quasicrystal" is extraterrestrial in origin.
The pattern of atoms in a quasicrystal falls short of the perfectly regular arrangement found in crystals. Until January, all known quasicrystals were man-made. "Many thought it had to be that way, because they thought quasicrystals are too delicate, too prone to crystallization, to form naturally," study researcher Paul Steinhardt of Princeton University told LiveScience at the time.
Then researchers announced the presence of a natural quasicrystal in a meteorite found in the Koryak Mountains of Russia. . That meteorite was being kept in a museum in Italy. Now, on an expedition to the site where it was found in Russia, Steinhardt and his colleagues now have found more natural samples of quasicrystals for analysis.
Quasicrystals were first synthesized in a lab in 1982 by Israeli chemist Dan Shechtman, whose work won the Nobel Prize for Chemistry in 2011. Regular crystals are made up of regular clusters of repeating atoms arranged in particular symmetries. Quasicrystals are orderly, too, but they do not exactly repeat themselves. If regular crystals are like boring bathroom tiles, quasicrystals are like complex tile mosaics.