In the meteorite rock of the Koryak Highlands in Chukotka, scientists discovered a quasicrystal formed in natural conditions - a solid body with an irregular type of symmetry. In "real" crystals, the atoms are in an ordered repeating lattice. Quasicrystals have an ordered but not periodic structure. Since 1982, these have been successfully synthesized in laboratory conditions, but do not occur in nature.
American and Italian geophysicists investigating the Khatyrka meteorite, which fell about 10 thousand years ago into the basin of the river of the same name and was discovered in 2011, revealed a natural quasicrystal. It has the symmetry of an icosahedron - 20 faces, each of which is an equilateral triangle. The structure of the find is described in Scientific Reports.
The size of the mineral, designated "126A", is approximately 0.4 millimeters in diameter. It is dark gray in color with visible reflective metal components. It should be noted that "126A" is the third natural quasicrystal. The first two are also parts of the Khatyrka meteorite, but the current one has a number of features. It also consists of aluminum, copper and iron, but the ratio of these elements in each object is different. In addition, the find became the first sample found in nature even before synthesis in the laboratory. The specialized software used by the researchers was unable to index the mineral model in any existing crystalline system.
How a quasicrystal could have formed in a meteorite remains a mystery. Scientists suggest that the formation of unusual symmetry occurred when two celestial bodies collided, which caused an inhomogeneous distribution of pressures and temperatures. In some parts of the meteorite, these figures reached 5 gigapascals and 1200 degrees Celsius. The study of this issue will improve the technology for the production of synthetic crystals.
Timur Alimov