In collaboration with the California Institute of Technology, a research group led by Tohoku University Graduate School of Science, Department of Geography, discovered a new species of mineral from the oldest material in the solar system in meteorite samples.The mineral was named Rubinite after Dr. Alan E. Rubin of the University of California, Los Angeles, who is famous for his research on meteorites, and was recognized as a new mineral by the International Mineralogical Association.
Immediately after the birth of the solar system about 46 billion years ago, solid substances of about 1 mm to 1 cm condensed from high-temperature nebula gas near the primitive sun are difficult to volatilize because they are rich in non-volatile elements such as Ca, Al, and Ti. It is called a sexual inclusion.It is contained in a meteorite called chondrite that came from an asteroid that did not undergo melting or differentiation during the evolution of the solar system.Refractory inclusions are said to record information immediately after the birth of the solar system as the oldest solid substance in the solar system, and have been considered important for understanding the formation and evolution process of the solar system.
The research group conducted scanning electron microscopic observations of the Allende meteorite, which is a type of primitive chondrite meteorite, and discovered minute minerals consisting of elements such as Ca, Ti, Si, and O.As a result of detailed analysis of the chemical composition and crystal structure, this mineral was found to be a new species of garnet with the chemical formula Ca3Ti3 + 2Si3O12.Substances with the same chemical formula have already been artificially synthesized, but this is the first time they have been discovered as natural minerals.A similar mineral was discovered at the same time by another chondrite meteorite (Vigarano meteorite) by Dr. Chi Ma of the California Institute of Technology.
In the future, we will conduct detailed mineralogical, petrological, and isotopic cosmochemical analyzes of rubinite, and consider under what conditions this mineral was formed by combining the results of thermodynamic calculations. , It is expected that new constraints will be given to the physicochemical conditions in the primordial solar system nebula.
