Secret building materials: "space" minerals found in Russia
For the first time, scientists have discovered two minerals on Earth that were previously considered characteristic of meteorites that fell on the surface of our planet. The finds were made in the Norilsk ore region in the north of the Krasnoyarsk Territory and in rocks belonging to the Dead Sea basin. The results obtained indicate that the conditions necessary for the formation of "cosmic" minerals may occur in the Earth's crust. The discovery will allow for a better understanding of how iron-enriched asteroids and planetary cores form. In the future, unusual materials may help in the construction of extraterrestrial habitable stations and the creation of unique equipment, experts told Izvestia.
"Space" hardware on Earth
Scientists from St. Petersburg State University, the Institute of Diamond and Precious Metals Geology (Yakutsk) and Ben-Gurion University (Israel) have for the first time discovered two oxygen-free minerals typical of iron meteorites — haksonite and wakitite — in rocks of the upper crust.
High-temperature metamorphic rocks of the Hatrurim formation
The finds were made in the Norilsk ore region in the north of the Krasnoyarsk Territory and in rocks belonging to the Dead Sea basin in Israel — in the Hatrurim formation, that is, in geological formations that are also called the "Spotted Zone". Interestingly, uakitite was discovered relatively recently by other Russian researchers in an iron meteorite. It was found in the summer of 2016 on the territory of the Bauntovsky Evenki district in Buryatia. And khaksonite (iron and nickel carbide) was discovered, among other things, in the famous Chelyabinsk meteorite.
Meteorites are fragments of asteroids and planets that have reached the surface of a planet. As scientists explained to Izvestia, some of them mainly consist of an alloy of iron and nickel and contain oxygen-free minerals unusual for Earth, including carbides, phosphides and nitrides. The formation of minerals in which carbon, phosphorus, or nitrogen are negatively oxidized and bound to metals is not typical for rocks of the Earth's crust. Instead, oxygen-containing minerals are formed: iron oxides, as well as carbonates, phosphates, and nitrates.
Native iron was found on Earth back in the 19th century on Disko Island (Greenland). However, for a long time it was believed that in the upper shells of our modern planet there are no conditions in which its "space" satellites, typical of iron meteorites, could form. Finds of such minerals were almost always interpreted as an indicator of the extraterrestrial origin of the samples.
In the new work, scientists have discovered both minerals in the form of microscopic inclusions in the rock in association with native iron. According to experts, haxonite has the appearance of white-yellow shiny needle-like crystals fused with native iron. These are the structures this mineral forms in iron meteorites. Uakitite occurs as golden-yellow small grains among crystals of native iron, schreibersite (iron phosphide), troilite (iron sulfide) and dobreelite (chromium sulfide).
Native iron (bulk) and cogenite (iron carbide, yellow) in igneous rocks of Siberia
Scientists have analyzed the mineral association of terrestrial native iron and iron meteorites and found their significant similarities. The researchers suggested that the conditions for the formation of native iron on Earth and some iron meteorites coincide.
— Interest in the minerals that make up iron-rich meteorites and asteroids has increased significantly in recent years due to the launch of NASA's Psyche space mission. This is a program in which specialists will study the chemical and mineral composition of the metal-rich asteroid of the same name. Now it is extremely important to understand which mineral phases may be present in it and what conditions are needed for their formation, since the spacecraft is equipped with only a set of remote sensing devices, which limits the ability to analyze the substance of Psyche in detail," Oleg Vereshchagin, Candidate of Geological and Mineralogical Sciences, Associate professor of the Department of Mineralogy at the Institute of Earth Sciences of St. Petersburg State University, told Izvestia.
Previously, scientists described a new mineral they found in the rocks of the Norilsk ore region and named olgafrankite. It consists of nickel and germanium and was also found in the Rumuruchi meteorite, which may indicate its presence in other meteorites.
What does the discovery of "comic" minerals mean?
Asteroid iron is characterized by very high purity, and it is it that has greater corrosion resistance, Evgeny Alexandrov, director of the NTI Center for Digital Materials Science: New Materials and Substances at Bauman Moscow State Technical University, told Izvestia. They are present in too small a volume on Earth, but their research is promising for subsequent use directly in space for the construction of habitable stations.
Native iron (bulk), cogenite (iron carbide, yellow) and native copper (red) in igneous rocks of Siberia
— It is difficult to obtain similar minerals in the laboratory and in production, since this requires reproducing the processes occurring in the earth's crust or in space. However, if valuable characteristics of such materials are discovered, for example, to create unique tools (machine tools) or reliable chemical reactors for aggressive environments, one should know the conditions for obtaining such minerals and the technological possibilities for their production and processing," the expert noted.
The form of iron's location or state in this case is interesting for astronomers and astrophysicists from the point of view of the history and processes of the formation of the Universe, says Vladislav Ivanenko, CEO of Sputnix, expert of the Aeronet NTI working group.
It is difficult to say about any practical application of these studies, Mikhail Vinnik, a leading researcher at the Moscow State University Museum of Earth Sciences, told Izvestia.
— Colleagues have made an important step in understanding the solar system. They have once again confirmed that the solar system and the universe as a whole are built of the same bricks," the expert emphasized.
Currently, about 500 minerals found in meteorites are known, which is ten times less than the total number of mineral phases well studied on Earth, said Viktor Grokhovsky, head of the UrFU Extra terra Consortium laboratory.
— But what is the interest of space minerals? They were formed in extreme space conditions (temperature, pressure, radiation, time), which are unattainable in terrestrial technologies, which gives earthlings hints about the influence of these conditions and processes on materials and the possibility of creating new technologies," the scientist said.
According to him, the fate of minerals found on Earth is different. The mineral haxonite, an iron and nickel carbide named after the metallologist Howard Exxon, is still not possible to obtain in terrestrial conditions.
— Another compound, vanadium nitride, is well known to metallurgists and machine builders. Having a high melting point and wear resistance, it is sprayed in vacuum onto the surface of critical parts. In steels, it increases strength and prevents the structure from changing when exposed to temperature," the scientist noted.
The results of the study, supported by a grant from the Russian Science Foundation (RSF), are published in the Journal of Geophysical Research: Planets.
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