Vol 148, No 3 (2019)

The paper generalizes data on symmetry of minerals in different Earth’s envelops as a function of temperature, pressure and combined effect of both these parameters. It is shown that distribution of mineral species in the symmetry hierarchy, in particular — existence of the monoclinic maximum and the triclinic minimum in the symmetry statistics of the world of minerals and non-organic compounds, is determined, first of all, by two diversified factors: dynamic properties of the crystal lattice (quantity of the unit cell parameters not fixed by the symmetry) and the crystal structure efficiency (maximum multiplicity of atomic positions allowed by the given point-to-point group). With increase of temperature the symmetry of the substance becomes usually higher, the permanently increasing pressure makes it lower, but rising again with its reconstruction. Mutual increase of temperature and pressure with depth inside the Earth provides the stable elevation of the average symmetry of rock — from single units up to the maximum value 48 of the Dolivo-Dobrovolsky index. Multiparametricity of the minerals symmetry statistics allows to leave without comments some fluctuations of this function until their verification by time.

Belogubite, ideally CuZn(SO₄)₂·10H₂O, has been found in the supergene zone uncovered by the open pit at the Gayskoe massive sulfide Zn-Cu deposit (Orenburgskaya region, the South Urals, Russia). It is associated with dietrichite and may contain relics of quartz. Belogubite forms aggregates of blue grains up to 1 mm in size. The mineral is transparent with vitreous luster and white streak. Its color varies from pale equant to light blue. Cleavage and parting were not observed. The new mineral is brittle and has Mohsʼ hardness ca. 2½. Its density measured by floatation in bromoform+ethanol is 2.27(2) g/cm^–3, its calculated density is 2.249 g/cm^–3. Belogubite is biaxial (–), α = 1.512(2), β = 1.525(2), γ = 1.531(2); 2V (meas.) = 70(10)°, 2V (calc.) = 67.9°. Dispersion is noticeable, r < v. The mineral is nonpleochroic. Chemical composition of the holotype sample is (wt %, electron microprobe data, H₂O determined by thermogravimetry): MgO 1.12, MnO 0.10, FeO 3.15, CuO 8.98, ZnO 18.02, SO₃ 32.49, H₂O 36.75, total 100.61. Its empirical formula calculated on the basis of 18 O apfu is: (Cu_0.55Zn0_.45)_Σ1.00(Zn_0.64Fe_0.22Mg_0.14Mn_0.01)_Σ1.01S_1.99O_7.98·10.02H₂O. The structure was solved by direct methods and refined on the basis of 1797 independent reflections to R = 0.016. Belogubite is triclinic, P1̅ . Unit cell parameters are: a = 6.2548(1), b = 10.6112(2), c = 6.0439(1) Å, α = 82.587(1), β = 109.625(1), γ = 104.848(1)°, V = 364.81(1) ų, Z = 1. The strongest reflections of the powder XRD pattern are [d_obs, Å (I) (hkl)]: 5.73 (35) (100), 5.576 (47) (–110), 4.873 (100) (–111), 3.907 (31) (021), 3.719 (45) (0 –21), 3.229 (27) (111), 2.915 (25) (–221), 2.684 (26) (130). Belogubite is a new, CuZn-ordered member of the chalcanthite group having M1 cationic site preferentially occupied by Cu whereas M2 site is dominated by Zn with subordinate substitution of Fe²⁺ and Mg. The mineral is named in honor of Elena Vitalievna Belogub (born 1963), major researcher of the Institute of Mineralogy of the Urals Branch of Russian Academy of Sciences, Miass, Chelyabinsk Oblast, Russia, a well-known expert in the mineralogy of volcanic-hosted massive sulfide copper deposits of South Urals.

For the first time, lithium-fluoric granites and ongonites of the Arga-Ynnakh-Khaysky massif (East Yakutia) have been revealed to contain an accessory complex of tungsten-bearing tantalum-niobates (columbite-(Fe), columbite-(Mn), tantalite-(Mn), minerals of microlite group, tantalic rutile) including «wolframoixiolite». These rocks containing wolframoixiolite, their composition and typomorphic features are described: they are highly ferriferous, with major geochemical role of niobium and wide variations of tungsten and tantalum concentrations. Wolframoixiolite occurs there in paragenesis with tungsten-bearing columbite-(Mn), tantalum-niobium ferberite, lepidolite and topaz. Wolframoixiolite of the Arga-Ynnakh-Khaysky massif was formed on a late-magmatic stage of lithium-fluoric granites crystallization by polymorphic transformation of columbite-(Fe). The study of accessory mineralization in rare-metal granites of Eurasia allows, taking into account a new find, to draw a conclusion, that wolframoixiolite is typomorphic accessory mineral in lithium-fluoric granites and may be looked as the indicator of rare-metal-granite magmatism with accompanying tin-rare-metal ore mineralization.

The paper reports, for the first time, on cryogenic minerals and flowstones in the Starateley cave on the River Sosʼva (the Northern Urals). The cave was found and explored in 2011; presently it is one of the largest, in terms of its volume, underground caverns in the Sverdlovsk Region. Upon our visit in 2016 in addition to «common»speleothems, such as cryogenic flour and flowstone, we have found peculiar aggregates of yellowish calcite as well as cave pearls. The depleted O and enriched C isotope signatures indicate cryogenic origin of this calcite and its formation from slowly freezing solution. Dating cryogenic calcite with ²³⁰Th/²³⁴U method allow to constraint the time of climate warming-related thawing of permafrost on the eastern slope of the Northern Ural Mountains to 85.4 ± 0.5 ka BP. The age of cave pearls is Holocene (7.4 ± 2.1 ka BP). Stalagmite sample has not been dated due to low U contents and inferred «open system» behavior of U and Th isotopes.

In situ high-temperature powder X-ray diffraction (HTPXRD) and differential scanning calorimetry (DSC) of three natural borosilicates have been performed in the temperature range of 25—1200 °С. Axinite-(Mn) melts incongruently at 900 °С forming anorthite and bustamite. Leucosphenite decomposes at 850 °С to fresnoite and cristobalite. According to DSC data, kornerupine decomposes at 1177 °С and sapphirine, indialite, and spinel were observed as the products of kornerupine heating. The calculation and orientation of thermal expansion tensor have been performed using HTPXRD data. The study showed that the borosilicates expand weakly and almost isotropically. The average volumetric thermal expansion coefficients are 21.3, 22.7, and 32.9 ∙ 10^–6 °C^–1 for axinite-(Mn), kornerupine, and leucosphenite, respectively. Leucosphenite has a maximum volumetric expansion most likely due to the pronounced layered character of the crystal structure. The least symmetric structure of axinite-(Mn) has the maximal anisotropy of thermal expansion in the temperature range of 600—900 °C. 

«Compact» quartz of the Oka-Urik block is a new source of ultra-pure quartz raw materials. Large bodies of «compact» quartz are located in the south-western part of the block. The samples are opaque, gray-white, but translucent in thin chips and have the form of a clouded single crystal of quartz. Quartz grains are slightly elongated in one direction. There are two generations of quartz grains. There are single needles and scales of sericite. A distinctive feature of the «compact» quartz from other quartzites of the Oka-Urik block is that fluid inclusions were widely distributed here inside the quartz grains, and only rarely within intergranular spaces. Size of fluid inclusions is to 40 microns. Three types of fluid inclusions by composition were found in the sample of «compact» quartz: water-salt, water and carbon-containing-water. The concentration of salts in fluid inclusions of water-salt composition corresponds to 7—9 wt % NaCl equiv. Chemical enrichment of quartz concentrates showed that the main part of high-temperature water, carbon dioxide and sodium is in fluid inclusions. Based on the data obtained, an enrichment scheme was proposed. Calcination of quartz grits in vacuum at a temperature of 1450 °C for three hours led to a decrease in sodium concentration, as there is an opening of the fluid inclusions inside the grain.

The article is devoted to the consideration of new interpretations of the Curie dissymmetry principle in the book by V. P. Afanasyev (2018) and the article by B. S. Levin (2018). It is shown that correct understanding of the symmetry and dissymmetry categories, and the Curie principle as a whole does not need the nature perception to be divided into the logical and ontological levels. It is noticed that Curieʼs principle relates to superpositions of homogeneous phenomena. Superpositions of heterogeneous phenomena should be preliminary divided into homogeneous parts using the methods of relative or absolute geochronology. Directions for further research on the Curie principle are suggested.

In 2019, February 6, there was a presentation of the book «Stone-cut Items in the Fersman Mineralogical Museum Collection» by Marianna B. Chistyakova in the Fersman Mineralogical Museum and in the Gokhran of Russia. This book is the first full description of the unique gem and art stones collection of the Museum. The book presentation is a big cultural event in Moscow and in Russia.

Nadezhda N. Mozgova — an outstanding mineralogist, Professor, doctor of geological and mineralogical Sciences, honorary member of the all-Russian mineralogical society passed away at the age of 88, after a severe and long illness. Nadezhda Nikolaevna will forever remain in the memory and in the hearts of friends, colleagues and students as an excellent specialist and a wise tutor.