مجله بلور شناسی و کانی شناسی ایران
سال بیست و پنجم شماره 3 (پیاپی 69، پاییز 1396)

The Mashhad ultramafic complex with a Permo-Triassic stratigraphic age is exposed at the NE of Binaloud Mountain and the SW to NW of Mashhad city. This area is mainly composed of mafic and ultramafic rocks, metamorphosed carbonate and pelitic rocks and granitoids in a NW- SE trend. Serpentinized amphibole-peridotites are the main types of ultramafic rocks in this area. Minerals in these rocks include olivine, orthopyroxene, clinopyroxene, brown amphibole and opaque minerals as the original minerals and serpentinite group minerals, tremolite, actinolite, chlorite, talc and carbonate minerals are the secondary minerals. The amphiboles are commonly of two types. One comprises brown to red-brown subhedral pargasites. The second type is seen as colorless or pale green unhedral tremolite-actinolite. Variations in the cation proportions of Al, Fe, Cr and Ti in structure of amphiboles are strongly influenced by adjacent minerals (e.g. olivine and pyroxene, especially iron-bearing phases such as chromite). Petrographic (textural relationships between minerals) and mineral chemistry data indicate that the pargasites in amphibole-peridotite in the study area compatible with metasomatized mantle peridotites in a subduction zone.

The Beshgaz manganese-bearing veins are located in ~45 km northeast of Birdjand, South-Khorasan, and east of Iran. These veins with 0.1-1.5 m thickness and 4-7 m length are engulfed discordantly within Paleocene (Eocene-Oligocene) volcanic-pyroclastic rocks. The host of Mn-bearing veins are dacite to rhyo-dacite tuff, lapilli tuff with andesitic and andsi-basaltic fragments in shear zones. The Mn grade reaches up to 45% in the vein/veinlets. The major Mn ore minerals are pyrolusite, cryptomelane, and psilomelane. Ore minerals showing colloform and open-space filling textures. Amorphous silica is the principal gangue mineral in the Mn ores and the SiO2 content of these veins vary from 2.41 in Mn-bearing veins to 20.98 % in silicic zone. Based on mineralographic and geochemical data, the Mn ores were preliminarily precipitated as amorphous Mn-oxide and hydroxide gels, and gradually psilomelane and then pyrolusite were developed in expense of the primary amorphous minerals. The average ratio of Mn/Fe in Beshgaz manganese-bearing veins is 26.31 and positive correlation of manages with Ba, Sr, U, and Zn in Mn-bearing veins indicate that these veins have formed as epigenetic by hydrothermal fluids.

The Upper Cretaceous volcanic and subvolcanic rocks from the Nageleh Sar, south of Mahmood Abad town in north Iran are dolerite, olivine basalt, trachyandesite and alkali trachyte. These units in an ordered stratification are set in a way that creates a syncline with WNW-ESE axial trend. The chemical data and discrimination diagrams represent medium alkaline bimodal series for the studied samples. REE and incompatible trace elements patterns indicate that they mostly originated from a mantle source similar to OIB with orthopyroxene, clinopyroxene, and olivine in terms of mineralogical content. Variation diagrams and patterns on spider diagrams imply that the parental magma evolved by dominant process of fractional crystallization. The diagrams of major and trace elements ratios clearly show that fractionated phases are often clinopyroxene, amphibole, iron, and titanium oxides. The generating magma of these rocks has been contaminated by crustal materials to some extent and emplaced in an intercontinental rift setting.

Considering the high resistance of quartz against stress and alteration, this mineral was chosen for Geothermobarometry in Almogholagh intrusive masses. To determine the temperature and pressure of crystallization of quartz, the amount of Ti contained in the quartz was measured by Electron Microprobe –Analyzer method and then, the pressure and temperature of crystallization of analyzed points were calculated. The growth and crystallization temperature range of quartz was determined using the P-T diagrams were drawn and contoured. The results show that the negative effects of stress and active fluids on the calculated crystallization temperature can be reduced by contouring. Moreover, in this study, it was found that quartz crystals of intermediate-to-basic rocks and the acidic rocks have been crystallized in a temperature range of 683 to 757 °C and 667 to 741 °C respectively. The examination of fluid inclusions in quartz veins by heating and freezing stage microscope showed that silicic veins in intrusive masses and in the immediate adjacent rock have been formed at temperatures between 134 to 255 °C.

The Gazanjeh bauxite deposit (SE Mahabad, West-Azarbaidjan province) is a typical residual sedimentary deposit with dolomitic limestone host rock of Permian age in northwestern Iran. Calculations of normative values of minerals using obtained results from XRD and XRF analyses in a selected profile indicate that diaspore, hematite, and pyrophyllite were major mineralogical phases of this deposit and include 71.73 to 94.66 % of mineralogical composition of ores, approximately. Based on normative values of minerals, this deposit was formed from two-type ores, (1) clayey bauxite and (2) iron-rich bauxite. Based upon chemical analyses, REE values vary in the ores from 30.14 to 379.55 ppm. Values of La/Y, Eu/Eu*, and Ce/Ce* in the ores are within the ranges of 0.33-3.16, 0.57-1.36, and 0.87-7.05, respectively. Combination of the obtained results from investigation of trend of lanthanides changes and elemental ratios in the selected profile suggest that factors such as change in physico-chemical conditions of depositional environment (pH and Eh), fluctuations in level of groundwaters table, degree of complexation with carbonatic lighands, difference in the stability of lanthanides-bearing minerals, and mineral control have played the important role in distribution and mobilization of REEs during formation and development of the studied bauxitic ores.

Dehzaman iron deposit is located southwest of Bardaskan, Khorasan Razavi province, and northeast of Kashmar-Kerman Tectonic Zone. Geology of the study area consists of late-Neoprotrozoic-lower Cambrian metamorphsed volcano-sedimentary units, including slate- phyllite, sericite schist, recrystallized carbonate rocks, metarhyolite-metarhyodacite and granitic intrusions. Mineralization is hosted by metarhyolite-metarhyodacite as vein-veinlet, massive, brecciate, and dessiminated forms. Magnetite, specularite (low Ti and V), apatite micrograins associated with chlorite, calcite, and quartz are the most important minerals at deposit. Minor chalcopyrite is present. Hematite and malachite are the main secondary minerals. The main alterations of the area are chloritic, carbonate, silicification, potassic and tourmalinization. Tectonic setting, host rock, mineralogy, alteration, and structure and texture of this part of Dehzaman deposit have the most similarity with the Kiruna type iron deposits

Regarding the growing uses of the nanoclay for different applications nanoclay characterization has become highly important. However, there is not enough information about a developed characterization methodology of nanoclay materials. In this study the montmorillonite was purified using different physical or chemical methods and the purity of montmorillonite in the nanoclay samples were characterized using different methods such as XRD, SEM/EDX, FTIR, TG/DTA, and CEC. Results indicated that parallel comparison of results of different characterization methods would provide important information about the type of clay mineral, type of non-clay mineral in the samples, semi-quantification of minerals in produced nanoclay, and change in the nanometric characteristics of the nanoclay. Combination of XRD and SEM/EDX results provided interesting information about the amount of impurities in the nanoclay samples in addition to their structural morphology. Comparison of the CEC with the XRD results of the treated nanoclay samples provided information about type of clay in the nanoclay samples. And finally combination of XRD and TG results provided information about the type of other clay minerals (non-montmorillonite ones) in addition to existence of organic impurities in the nanoclay samples.

The Beshgaz manganese-bearing veins are located in ~45 km northeast of Birdjand, South-Khorasan, and east of Iran. These veins with 0.1-1.5 m thickness and 4-7 m length are engulfed discordantly within Paleocene (Eocene-Oligocene) volcanic-pyroclastic rocks. The host of Mn-bearing veins are dacite to rhyo-dacite tuff, lapilli tuff with andesitic and andsi-basaltic fragments in shear zones. The Mn grade reaches up to 45% in the vein/veinlets. The major Mn ore minerals are pyrolusite, cryptomelane, and psilomelane. Ore minerals showing colloform and open-space filling textures. Amorphous silica is the principal gangue mineral in the Mn ores and the SiO2 content of these veins vary from 2.41 in Mn-bearing veins to 20.98 % in silicic zone. Based on mineralographic and geochemical data, the Mn ores were preliminarily precipitated as amorphous Mn-oxide and hydroxide gels, and gradually psilomelane and then pyrolusite were developed in expense of the primary amorphous minerals. The average ratio of Mn/Fe in Beshgaz manganese-bearing veins is 26.31 and positive correlation of manages with Ba, Sr, U, and Zn in Mn-bearing veins indicate that these veins have formed as epigenetic by hydrothermal fluids.

The Byarjomand Batholith with Pre-cambrian age in the north Semnan, north-central Iran, consists of granite, granodiorite, quartz monzodiorite and gabbrodiorite. These rocks have granular texture and occasionally granophyric, pertite and poicelitic textures. Crystal size distribution (CSD) studies can reveal magmatic processes. In order to determine volometric proportion, growth time and nucleation rate of feldspar crystals and magma crystallization rate, feldspar crystals from 8 samples of granite, granodiorite and quartz monzodiorite rocks have been studied to quantitative analysis by JMicrovision and CSD Corrections softwares and then the results of the analysis of various samples were compared together. The calculated volumetric proportion indicates that percent of these minerals vary from 10.95 (in quartz monzodiorite) to 39.2 (in granites). According to growth rate (10-10 mm/s) and CSD graphs slope (-3.93 ­- -6.88), samples have grown in different time ranges, and growth time in the granodiorite and granites is more than quartz monzodiorite as growth time procure 54.29 to 81.93 years in granite rocks and 46.08 years in quartz monzodiorite rocks. Also nucleation rate in quartz monzodiorite is maximum and granites and granodiorite have minimum amounts. So crystal presence in the granodiorite and granites are larger than crystals of quartz monzodiorites and it is compatible with petrographic observations and indicates the important of different physical conditions prevailing in the magma solidification. In the some of the frequency distribution curves observed fractures and curvature that is due to contamination and magma mixing and fractionation process.

The influence of firing conditions on the mineralogical composition of clay base ceramics is studied. Experimental samples fired in oxidation atmosphere at temperature rates 850, 900, 950, 1000 and 1050AWT IMAGE with respect to high amount of CaO in raw materials (Ave. 18.76 %), these samples classified in Ca-rich clay group. The determination of chemical composition, phase structure and mineralogy were carried out by thin section petrography through Pol. Microscopy, XRF, XRD with Rietveld refinement method, TGA and mercury immersion porosimetry. The results show that the amount of quartz and the percentage of porosity are diminished with increasing of temperature. The presence of gehlenite, diopside, augite and wollastonite at 850AWT IMAGE and fassaite (at 950AWT IMAGE) are demonstrated formation of firing products. The results suggest that quantitative investigation on mineralogical changes and the co-existence of phases in experimental specimens, can provide appropriate pattern for estimating firing temperature and technology of archaeological potteries.

The Kamyaran ophiolite complex as a part of the Kermanshah ophiolite is located in western Iran, along the Zagros orogeny and Neotethys suture zone. The Kamyaran ophiolite complex includes serpentinized harzburgites, isotropic and layered gabbros, diabasic dykes and pillow basalts. The diabasic dykes have experienced upper green schist facies metamorphism. Based on mineral chemistry of the diabasic dykes, plagioclases are oligoclase to andesine and clinopyroxenes are diopside in these rocks. Tetrahedral site is occupied completely by Si and partially by Al (AlIV) in the clinopyroxenes. Oxygen fugacity during crystallization of the diabasic dykes magma, calculated using crystallization composition, points to effects of subduction process on diabasic dykes of the Kamyaran ophiolite complex. Clinopyroxene crystallized at less than 5 Kbar pressure in the presence of almost 2.5 percent H2O. Chemistry of clinopyroxenes indicates IAT characteristics for the original magmas, showing a supra-subduction environment for generation of the Kamyaran ophiolites.

Kaolin deposits in the Nivasht and Kabudkamar areas are located in ~25 km northwest of Saveh, Central province. Field observations along with petrographic examinations revealed that genetically these deposits are alteration products of igneous rocks such as andesi-basalt, trachy-andesite, and andesitic tuff of upper Eocene age. In this study, the physical, chemical, and mineralogical properties of the kaolin deposits in Nivasht and Kabudkamar were investigated on the basis of industrial applications. Based upon mineralogical data, the principal constituent minerals in both deposits are quartz, kaolinite, halloysite, muscovite-illite, Montmorillonite, pyrophyllite, plagioclase, hematite, goethite, anatase, akermanite, alunite and/ or natroalunite, and talc. Further investigations in the studied areas showed that the kaolinitic clays have mostly firing color within the range of milky white to dark gray. Consideration of parameters such as capability of water absorption, resistance in dry state, firing contraction, low thermal efficiency, and the values of major oxides demonstrated that the kaolins at Nivasht and Kabudkamar possess suitable standard conditions for application in ceramic (for floor and wall) industries, however, their application in other industries requires further processing.

The structural, morphological and magnetic properties of Co0.5Zn0.5Fe2O4 nanoferrite thin films on glass substrates were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM), respectively. These thin films were deposited by spray pyrolysis method and subsequently calcined at 500 and 600 ˚C. The XRD results reveal that the calcined samples have a single-phase, and their crystallite size and lattice parameter increase as the calcination temperature increases. FE-SEM images exhibit a homogeneous grain size distribution for calcined thin films, and the grains size of samples calcined at 500 and 600 ˚C are ~ 20 and 35 nm respectively. The room temperature magnetic measurements indicate that the magnetization and coercivity of the samples in both parallel and perpendicular direction to applied magnetic field increase with calcination temperature. These can be attributed to the migration of non-magnetic Zn2 ions from octahedral to tetrahedral sites.

In this study Cu2ZnSnS4 (CZTS) thin films were deposited by sol–gel spin coating on glass substrates and the effect of metal salts ratio, annealing treatment with and without sulfur vapor on structural, morphological and optical properties of CZTS films were investigated. Our results were showed that all CZTS thin films have kesterite structure. Moreover increasing of zinc concentration and decreasing of copper content in deposition solution and annealing treatment improved crystallite quality and destructed secondary phases. The band gap energy of the annealed samples was in the range of 1.40 to 1.50 eV, which is convenient for application in solar-cells as an absorber layer. Comparison of the results showed that the morphology, structural and optical properties of annealed CZTS thin films in presence of sulfur are better than other samples.

In this research, lead-free piezoelectric Sodium potassium niobate nanopowders (K0.5Na0.5)NbO3 were synthesized using a modified sol–gel method. Nitrate sodium, nitrate potassium, and ammonium niobate oxalate were used as starting materials. Gelatin which is natural polymer was used as polymerization agent and distilled water was used as solvent. The crystal structure of the prepared powders is characterized using X-ray diffraction (XRD) and crystallite size, lattice strain and stress were estimated using Scherrer formula, Williamson-Hall (W-H), and Size-strain Plot (SSP) methods. TEM images showed that the morphology of the prepared particles is cubic, with the average size of about 100 to 200 nm. Selected area electron diffraction (SEAD) image of the samples were confirmed that the prepared particles have good crystallinity.

In this research, PbFe11Co1O19 with annealing temperatures of 600, 700, 750, 800, 850 and 900 ˚C at annealing time of 3 h were synthesized by sol-gel method. The structural, microstructure properties and morphology of the samples have been studied by XRD, FT-IR and FESEM. Also, magnetic and dielectric properties of samples were characterized by VSM and LCR meter. The results of measurements of structural show that phase percentage of lead hexaferrite by increasing annealing temperature up to 800 ˚C increase and at annealing temperatures more than 800˚C percentage this phase decreases. The results of the magnetic measurements of samples reveal that by increasing annealing temperature and by eliminating the second phases, the saturation magnetization increases. Also, the results of dielectric reveal that by increasing frequency, dielectric constant and dielectric loss decreases which indicates that samples could be suitable for use in devices. The result measurements show that the best sample is PbFe11Co1 O19 with annealing temperature of 800 °C and 3 h.

A nickel complex with pyridine-2,6-dicarboxylic acid formulated as [Ni(pydcH)2].3H2O was synthesized and its crystal structure determined with single-crystal X-ray at diffraction temperatures (296 K and 120 K). Pyridine-2,6-dicarboxyli acid deprotonated on one group of COOH and two pydcH- anion is coordinated to Ni(II) atom as a tridentate ligand forming a distorted octahedral environment. The phase transition in crystal system is obtained with differ in temperature. The title compound is crystallized in monoclinic system with P21/c space group at 296 K, while it is crystallized in triclinic system with CAWT IMAGE space group at 120 K.

The compound of (Htmb)2[Ni(pydc)­2)].H2O (1) (In that tmb and pydc are 3,3¢,5,5¢-tetramethyl benzidine and pyridine -2,6- dicarboxylic acid, respectively) was synthesized via the proton transfer method and the structure was determined by single crystal X-ray diffraction. This compound crystalized in monoclinic crystal system and C2/c space group. In the asymmetry unit of compound 1, there are half molecule of the [Ni(pydc)­2)]2- anionic complex, one protonated molecule of 3,3¢,5,5¢-tetramethyl benzidine as a counter ion and half of an uncoordinated water molecule. Extensive intermolecular N-H…O and O-H…N, hydrogen bonds along with π… π and C-H …π interactions contribute in self-assembly and formation of a novel supramolecular structure.