Electric Spark Creates ‘Impossible Quasicrystal’ On Earth

A team of researchers has discovered a new mineral accidentally created by a lightning strike or a downed power line in a wind-created dune in the Sand Hills of north central Nebraska.

The discharge produced extreme temperatures (over 1,710 degrees) that led to the formation of a fulgurite, a tube of fused and melted sand along with traces of melted conductor metal from the power line.

Within the fulgurite was found a dodecagonal quasicrystal, an “impossible crystal” previously not found occurring naturally on Earth.

Until a few years ago quasicrystals were only hypothesized by physicist. Unlike classic crystals of minerals, quasicrystals are composed of equally spaced atomic layers, but the arrangement of the atoms doesn’t repeat like in a classic crystalline structure. While crystals, according to the classical crystallographic rules, can possess only two-, three-, four-, and six-fold symmetries, quasicrystals can display a higher symmetry.

Quasicrystals are formed in extreme environments that rarely exist on Earth. The first examples were found in meteorite fragments, as a result of the high temperatures and pressure experienced during an impact. In 2021, researchers described quasicrystals from trinitite sample collected in the desert of New Mexico. Trinitite is a “human-made” glassy material formed accidentally in the blast of the first atomic bomb test on July 16, 1945, which resulted in the fusion of surrounding sand, the test tower, and copper transmission lines.

In the now described fulgurite sample, composed mostly of molten quartz (silicate-dioxide) from a sand-dune, the researchers found traces of a manganese-chromium-nickel-aluminum-silicate showing a 12-fold symmetry and quasicrystalline order that is impossible for ordinary crystals. The silicate derives from the molten sand and the chromium and nickel likely derives from a partially molten power line, still engulfed in the rock.

Extreme temperatures of at least 1,710 degrees Celsius were reached, as indicated by the presence of quartz glass in the sample. The fulgurite may have been created by a lightning strike that combined sand with material from downed power line or from electrical discharges from the downed power line alone.

The discovery shows how quasicrystals could form naturally on Earth or other planets with an atmosphere and thunderstorms.

The study “Electrical discharge triggers quasicrystal formation in an eolian dune” is published in the journal PNAS.

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