Research press release


Scientific Reports

Mineralogy: A new quasicrystal from outer space



今回、Paul Steinhardtの研究チームは、ハトゥイルカ隕石に含まれる鉱物粒子において新たな組成を同定した。なお、この鉱物粒子には、天然鉱物のイコサヘドライトも含まれている。Steinhardtたちは、この新しい準結晶がイコサヘドライトのように正二十面体対称(60回回転対称)を持つことを指摘し、衝撃(例えば、宇宙における天体との衝突)による融解を経て、高圧下で結晶化したという考えを示している。また、Steinhardtたちは、この新しい準結晶が、地球上でわずか3例目の天然の準結晶の発見であり、いずれもハトゥイルカ隕石から見つかっていることも指摘している。

The discovery of a new quasicrystal is detailed in an article published online in Scientific Reports this week. The mineral was identified in a fragment from a meteor which landed in Khatyrka in eastern Russia, and is the first quasicrystal to be discovered in nature prior to being synthesized in the lab.

Quasicrystals are crystal-like structures, in which the atoms are arranged in orderly patterns that never exactly repeat and have an infinite number of possible symmetries. The new crystal was found in a fragment from the Khatyrka meteorite, which was recovered during an expedition to the Koryak Mountains in far eastern Russia in 2011.

Paul Steinhardt and colleagues identified the new composition on a grain from the meteorite that also contains the naturally occurring mineral icosahedrite. The authors note that like icosahedrite, the new quasicrystal has icosahedral symmetry (i.e. it has 60 points of rotational symmetry). The authors suggest that the newly identified quasicrystal may have crystallized under high pressure following a period of melting induced by a shock, such as an impact with another object in outer space. The authors note that this is only the third example of a natural quasicrystal to be found anywhere in the world, all of which come from the Khatyrka meteorite.

doi: 10.1038/srep38117


メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週各ジャーナルからの最新の「注目のハイライト」をまとめて皆様にお届けいたします。