Scientists of the RAS SB Institute of the Earth Crust have discovered a new mineral--chrome-aluminum-povondraite. The International Mineralogical Association registered it in October of 2013, which was reported in the Science in Siberia newspaper by the journalist Galina Kiselyova. Leonid Reznitsky, Cand. Sc. (Geol. & Mineral.), is an author of the discovery. He is in the list of discoverers of 14 out of 25 mineral species found and studied at the RAS SB Institute of the Earth Crust. These rare samples are exhibited at the Mineralogical Museum of the institute. "The samples occupy several shelves" noted Larisa Ivanova, Cand. Sc. (Geol. & Mineral.), supervisor of studies of the museum. "Many minerals were named in honor of prominent explorers of the Baikal area and Eastern Siberia." For instance, nataliite was named after the outstanding researcher of the Precambrian Nataliya Frolova, kalininite--in commemoration of the remarkable mineralogist Pavel Kalinin who made an invaluable contribution to mineralogical studies in the Southern Baikal area. The minerals like florensovite, odintsovite, tausonite, and pavlovskiite were named in honor of geologists Nikolai Florensov, Mikhail Odintsov, Lev Tauson, and Yevgeny Pavlovsky who were active participants of initiation and development of academic science in Eastern Siberia. Names of some other minerals are based on local geography, for example, olkhonskite discovered in the metamorphic rocks of the Western Baikal area, and olekminskite found in the Murunsky alkaline massif in the Western Aldan rich in unusual mineralogical associations.

Among discoverers, Alexei Konev, Dr. Sc. (Geol. & Mineral.), plays one of the leading roles. In the Western Baikal area within the limits of Tazheransky alkaline massif, he discovered two new species--tazheranite and azoproite; their specimens are exhibited at the Mineralogical Museum. According to Ivanova, the first sample has a number of specific characteristics: it contains trivalent titanium (in place of typical tetravalent natural titanium) and has a low oxygen content with regard to the theoretical quantity. This mineral has high refraction and hardness properties. Its synthetic analogues--phianite and djevalite--are widely used as imitation of precious stones. The other mineral azoproite, classified as titanium-containing borate, was named in honor of the International Geological Association for Studies of Deep Layers of the Earth Crust.

One more interesting finding of Konev and his colleagues--a blue stone discovered in 2011 in the territory of the Murunsky alkaline massif--is worth mentioning here. First, scientists took it for a blue nephrite. After detailed studies, it turned out that the mineral was a variety of amphibole of unusual composition (a group of minerals incorporating also nephrite). Results of the studies and a description of the mineral were sent to the Russian and international committees for new minerals; scientists proposed to name it dianite in commemoration of the British Princess Di, who was then in the center of attention of mass media. However, this name was not approved, and the blue amphibole received a name of "magnesia-strontium-potassium richterite". But museum employees and stonecutters of Irkutsk still call this wonderful ornamental material dianite.

Experts of the RAS SB Institute of the Earth Crust made a series of important discoveries within the Slyudyansky mining center (southern littoral part of Baikal). This complex is rightfully called a global mineralogical reserve. Indeed, it is rich in highly interesting crystallographic materials, rare mineralogical species, big and well preserved samples; this territory is characterized by intricate and diverse mineral processes and geochemical combinations and, finally, has valuable and rare mineral deposits--all this makes this area highly interesting for specialists.

Rocks of the Slyudyansky complex keep a unique variety of chrome and vanadium minerals, including chrome- and vanadium-containing compounds of different classes, for example, nataliite, chromephillite, vanadiodravite, magnesiokulsonite, kalininite, florensovite, batisivite, oksivanite, and kuprokalininite, discovered by employees of the RAS SB Institute of the Earth Crust. These minerals often form new and most complete isomorphic series and rows known in the nature. Normally, the findings have peculiar composition and structure. According to Ivanova, the samples exhibited at the museum--kalininite, florensovite, and kuprokalininite discovered by Leonid Reznitsky, Yevgeny Sklyarov, and Zoya Ushchapovskaya in association with the colleagues, belong to a rather rare class of minerals--sulphides structured as regular oxygen spinels but with sulphur in place of oxygen. Compounds of chrome and sulphur have become a rare thing in the natural environment. Sulphospinels, as Ivanona states, are interesting for a combination of optic, magnetic, and dielectric properties, which makes these materials highly promising in terms of industrial application. For example, florensovite synthesized soon after the discovery, turned out to be a new compound in demand in semiconductor engineering.

The Slyudyansky complex is famous for its lazurite deposits of unusual color all over the world. The color of this mineral varies from light blue to dark indigo. There are samples of greenish and reddish violet shades. It was there, on the lazurite deposits, where employees of the RAS SB Institute of Geochemistry have recently discovered a new mineral--a polymorphic (rhombic) analogue of lazurite vladimirivanovite. The sample is also exhibited at the museum.

Iron-free wollastonite and diopside were found in the Slyudyansky crystal complex: they are typical industrial materials used as fillers to produce almost weightless dishware (its roasting temperature is decreased by 100-150 °C). Ceramic plates containing such compounds have a very long service life. Wollastonite is usually synthesized. Our country has a unique natural reserve of this material. Unfortunately, it has not been commercialized yet.

G. Kiselyova, Irkutsk Scientists Discovered a New Mineral.--"Science in Siberia", No. 50, 2013

Illustrations from the web-site of the RAS SB Institute of the Earth Crust

Prepared by Marina KHALIZEVA