This book provides an analysis of an actual problem of the evolution of deep matter under the conditions of the upper mantle, transition zone, and uppermost lower mantle. This issue has a fundamental importance in geochemistry, petrology, mineralogy, and crystalochemistry of the mantle, at different depths. The authors discuss new experimental research on the composition and conditions of the chromium-bearing minerals genesis and their associations in the Earth's mantle. The experimental data are compared with the natural mineral assemblages, allowing a refinement of the structure and composition of the deep Geospheres of the Earth. The results of the physicochemical experiments in the "MgO-SiO2-Cr2O3" model and the multicomponent systems play a major role in understanding the phase diagrams of these systems, the structural patterns of chromium-bearing phases and the influence of Cr on P-T parameters in the Earth's mantle.

"Highlights in Mineralogical Crystallography" presents a collection of review articles with the common topic: structural properties of minerals and synthetic analogues. It is a valuable resource for mineralogists, materials scientists, crystallographers, and earth scientists. This book includes: An introduction to the RRUFF database for structural, spectroscopic, and chemical mineral identification. A systematic evaluation of structural complexity of minerals. ab initio computer modelling of mineral surfaces. Natural quasicrystals of meteoritic origin. The potential role of terrestrial ringwoodite on the water content of the Earth's mantle. Structural characterization of nanocrystalline bio-related minerals by electron-diffraction tomography. The uniqueness of mayenite-type compounds as minerals and high-tech ceramics.

This book describes the discovery of quasicrystals (icosahedral and decagonal) in an extraterrestrial rock from the Koryak Mountains of Far Eastern Russia. After a decade-long search for a natural quasicrystal, this discovery opened a new avenue in mineralogy and crystallography that could lead to further discoveries in geoscience, astronomy, condensed matter physics, and materials engineering. For the first time, minerals have been discovered that violate the symmetry restrictions of conventional crystallography. The natural occurrence of such crystals was unexpected, involving previously unknown processes. The fact that the quasicrystals were found in a meteorite formed in the earliest moments of the solar system means these processes have been active for over 4.5 billion years and have influenced the composition of the first objects to condense around the Sun. Finding quasicrystals formed in these extreme environments also informed the longstanding debate concerning the stability and robustness of quasicrystals. Recent shock experiments lend support to the hypothesis that the extraterrestrial quasicrystals formed as a result of hypervelocity impacts between objects in the early Solar system, and that they are probably less rare in the Milky Way.