Icosahedrite is the first known naturally occurring

quasicrystal A quasiperiodicity, quasiperiodic crystal, or quasicrystal, is a structure that is Order and disorder (physics), ordered but not Bravais lattice, periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks trans ...

phase. It has the composition Al₆₃Cu₂₄Fe₁₃ and is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

approved by the

International Mineralogical Association Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. ...

in 2010. Its discovery followed a 10-year-long systematic search by an international team of scientists led by

Luca Bindi Luca Bindi (born 1971) is an Italian geologist. He holds the Chair of Mineralogy and Crystallography and is the Head of the Department of Earth Sciences of the University of Florence. He is also a research associate at the Istituto di Geoscienze ...

and Paul J. Steinhardt to find the first natural quasicrystal. It occurs as tiny grains in a small sample labelled "

khatyrkite Khatyrkite ( ) is a rare mineral which is mostly composed of copper and aluminium, but may contain up to about 15% of zinc or iron. Its chemical structure is described by an approximate formula or . It was discovered in 1985 in a Placer deposit, ...

" (catalog number 46407/G, housed in The Museum of Natural History,

University of Florence The University of Florence ( Italian: ''Università degli Studi di Firenze'') (in acronym UNIFI) is an Italian public research university located in Florence, Italy. It comprises 12 schools and has around 50,000 students enrolled. History The f ...

, Italy), collected from an outcrop of weathered

serpentinite Serpentinite is a metamorphic rock composed predominantly of serpentine group minerals formed by serpentinization of mafic or ultramafic rocks. The ancient origin of the name is uncertain; it may be from the similarity of its texture or color ...

in the Khatyrka

ultramafic Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are usua ...

zone of the Koryak-Kamchatka area, Koryak Mountains, Russia. The rock sample also contains

spinel Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , a diminutive form of ''spine,'' in reference to its pointed crystals. Prop ...

, diopside,

forsterite Forsterite (Mg2SiO4; commonly abbreviated as Fo; also known as white olivine) is the magnesium-rich Endmember, end-member of the olivine solid solution series. It is Isomorphism (crystallography), isomorphous with the iron-rich end-member, fayalit ...

nepheline Nepheline, also called nephelite (), is a rock-forming mineral in the feldspathoid groupa silica-undersaturated aluminosilicate, Na3 K Al4 Si4 O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatit ...

sodalite Sodalite ( ) is a tectosilicate mineral with the formula , with royal blue varieties widely used as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite is a member of th ...

corundum Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium, and chromium. It is a rock (geology), rock-forming mineral. It is a naturally transparency and translucency, transparent material, but ...

stishovite Stishovite is an extremely hard, dense tetragonal form ( polymorph) of silicon dioxide. It is very rare on the Earth's surface; however, it may be a predominant form of silicon dioxide in the Earth, especially in the lower mantle. Stishovite w ...

, cupalite and an unnamed AlCuFe alloy. Evidence shows that the sample is actually extraterrestrial in origin, delivered to the Earth by a CV3

carbonaceous chondrite Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small propo ...

asteroid that dates back 4.5

Gya Gya or GYA may refer to: * Gya (unit), symbol for ''gigayears ago'', a unit of time equal to one billion (short-scale, i.e. 1,000,000,000) years before present. * Gya, symbol for the gray, a unit of radiation exposure, equal to 100 roentgen * Gy ...

. A geological expedition has identified the exact place of the original discovery and found more specimens of the meteorite. The same Al-Cu-Fe quasicrystal phase had previously been created in the laboratory by Japanese experimental metallurgists in the late 1980s. The concept of quasicrystals — along with the term — was first introduced in 1984 by Steinhardt and

Dov Levine Dov I. Levine (; born July 19, 1958) is an American-Israeli physicist, known for his research on quasicrystals, soft condensed matter physics (including granular materials, emulsions, and foams), and statistical mechanics out of equilibrium. Educa ...

, both then at the University of Pennsylvania. The first synthetic quasicrystal, a combination of aluminium and manganese, was reported in 1984 by Israeli materials scientist Dan Shechtman and colleagues at the U.S. National Institute of Standards and Technology, a finding for which Shechtman won the 2011

Nobel Prize for Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

."Impossible" crystal discovery
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References

{{Reflist Native element minerals Aluminium minerals Copper minerals Iron minerals Geology of Russia Quasicrystals Copper alloys Aluminium alloys