Subjects -> MINES AND MINING INDUSTRY (Total: 82 journals)
Showing 1 - 42 of 42 Journals sorted by number of followers
Stainless Steel World     Full-text available via subscription   (Followers: 18)
Journal of Applied Geophysics     Hybrid Journal   (Followers: 16)
Journal of Metamorphic Geology     Hybrid Journal   (Followers: 15)
International Journal of Hospitality & Tourism Administration     Hybrid Journal   (Followers: 14)
European Journal of Mineralogy     Hybrid Journal   (Followers: 12)
Journal of Geology and Mining Research     Open Access   (Followers: 11)
Contributions to Mineralogy and Petrology     Hybrid Journal   (Followers: 11)
Mineral Processing and Extractive Metallurgy : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 11)
Transactions of Nonferrous Metals Society of China     Hybrid Journal   (Followers: 10)
Journal of Human Resources in Hospitality & Tourism     Hybrid Journal   (Followers: 9)
Clay Minerals     Hybrid Journal   (Followers: 9)
Minerals Engineering     Hybrid Journal   (Followers: 9)
Lithos     Hybrid Journal   (Followers: 9)
International Journal of Minerals, Metallurgy, and Materials     Hybrid Journal   (Followers: 9)
Natural Resources Research     Hybrid Journal   (Followers: 8)
Geotechnical and Geological Engineering     Hybrid Journal   (Followers: 8)
Rock Mechanics and Rock Engineering     Hybrid Journal   (Followers: 7)
International Journal of Rock Mechanics and Mining Sciences     Hybrid Journal   (Followers: 6)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
International Journal of Mining Engineering and Mineral Processing     Open Access   (Followers: 5)
Journal of Quality Assurance in Hospitality & Tourism     Hybrid Journal   (Followers: 5)
Mine Water and the Environment     Hybrid Journal   (Followers: 5)
International Journal of Mining and Mineral Engineering     Hybrid Journal   (Followers: 5)
Journal of the Southern African Institute of Mining and Metallurgy     Open Access   (Followers: 5)
Mining Engineering     Full-text available via subscription   (Followers: 5)
Resources Policy     Hybrid Journal   (Followers: 4)
International Journal of Mining Science and Technology     Open Access   (Followers: 4)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Mineral Processing and Extractive Metallurgy Review     Hybrid Journal   (Followers: 4)
Applied Earth Science : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 4)
International Journal of Mining, Reclamation and Environment     Hybrid Journal   (Followers: 4)
International Journal of Coal Geology     Hybrid Journal   (Followers: 4)
Physics and Chemistry of Minerals     Hybrid Journal   (Followers: 4)
Journal of Convention & Event Tourism     Hybrid Journal   (Followers: 4)
Mineralium Deposita     Hybrid Journal   (Followers: 4)
Lithology and Mineral Resources     Hybrid Journal   (Followers: 3)
Journal of Sustainable Mining     Open Access   (Followers: 3)
International Journal of Coal Science & Technology     Open Access   (Followers: 3)
Mining Journal     Full-text available via subscription   (Followers: 3)
Ghana Mining Journal     Full-text available via subscription   (Followers: 3)
Geology of Ore Deposits     Hybrid Journal   (Followers: 3)
Rocks & Minerals     Hybrid Journal   (Followers: 3)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 2)
Journal of Mining Science     Hybrid Journal   (Followers: 2)
Geomaterials     Open Access   (Followers: 2)
Mineralogia     Open Access   (Followers: 2)
BHM Berg- und Hüttenmännische Monatshefte     Hybrid Journal   (Followers: 2)
Mining Technology : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 2)
Extractive Industries and Society     Hybrid Journal   (Followers: 2)
International Journal of Coal Preparation and Utilization     Hybrid Journal   (Followers: 2)
Mineralogy and Petrology     Hybrid Journal   (Followers: 2)
Mining Report     Hybrid Journal   (Followers: 2)
Neues Jahrbuch für Mineralogie - Abhandlungen     Full-text available via subscription   (Followers: 2)
Archives of Mining Sciences     Open Access   (Followers: 2)
Journal of Materials Research and Technology     Open Access   (Followers: 2)
Gems & Gemology     Full-text available via subscription   (Followers: 1)
Journal of Analytical and Numerical Methods in Mining Engineering     Open Access   (Followers: 1)
Rangeland Journal     Hybrid Journal   (Followers: 1)
Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica     Open Access   (Followers: 1)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Mineralogical Magazine     Hybrid Journal   (Followers: 1)
CIM Journal     Hybrid Journal  
Natural Resources & Engineering     Hybrid Journal  
Mining, Metallurgy & Exploration     Hybrid Journal  
Podzemni Radovi     Open Access  
Rudarsko-geološko-naftni Zbornik     Open Access  
Journal of Mining Institute     Open Access  
International Journal of Mining and Geo-Engineering     Open Access  
Journal of China Coal Society     Open Access  
Réalités industrielles     Full-text available via subscription  
Mineral Economics     Hybrid Journal  
Minerals     Open Access  
Gold Bulletin     Hybrid Journal  
Minerals & Energy - Raw Materials Report     Hybrid Journal  
Similar Journals
Journal Cover
Canadian Mineralogist
Journal Prestige (SJR): 0.565
Citation Impact (citeScore): 1
Number of Followers: 6  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 0008-4476 - ISSN (Online) 1499-1276
Published by GeoScienceWorld Homepage  [17 journals]
  • From Structure Topology to Chemical Composition. XXXI. Refinement of the
           Crystal Structure and Chemical Formula of Selivanovaite, NaFe 3+ Ti 4 (Si
           2 O 7 ) 2 O 4 (H 2 O) 4 , a Murmanite-Group (Seidozerite Supergroup)
           TS-Block Mineral from the Lovozero Massif, Kola Peninsula, Russia

    • Free pre-print version: Loading...

      Authors: Sokolova E; Day MC, Hawthorne FC, et al.
      Abstract: ABSTRACTSelivanovaite, ideally NaFe3+Ti4(Si2O7)2O4(H2O)4, is a murmanite-group (seidozerite supergroup) TS-block mineral from the Lovozero massif, Kola Peninsula, Russia. The crystal structure of selivanovaite was refined in space group C, a 10.524(6), b 13.815(6), c 12.213(14) Å, α 99.74(6), β 107.45(8), γ 90.15(10)°, V 1666.8(26) Å3, R1 = 21.40%. The previously given chemical analysis has been modified to better fit the crystal structure: Nb2O5 8.51, ZrO2 2.94, TiO2 31.96, SiO2 30.62, Al2O3 0.05, Fe2O3 5.08, FeO 3.23, MnO 3.36, CaO 2.14, MgO 0.75, Na2O 2.47, H2O 8.88, sum 99.99 wt.%; H2O was determined from structure-refinement results: H2O = 3.34 pfu, OH = 1.05 pfu. The empirical formula calculated on 22 O apfu is: (Na0.63Ca0.30Mn0.36)Σ1.29(Fe3+0.50Fe2+0.35)Σ0.85(Ti3.14Nb0.50Zr0.19Mg0.15Mn0.01Al0.01)Σ4.00Si3.99O22.00H7.73, Z = 4. The crystal structure of selivanovaite [basic structure type B1(MG)] is an array of TS blocks (Titanium Silicate) connected via hydrogen bonds. The TS block consists of HOH sheets (H = heteropolyhedral, O = octahedral) parallel to (001). In the O sheet, the Ti-dominant MO(1,2) sites, Na-dominant MO(3) site, and □-dominant MO(4) sites give ideally Na□Ti2pfu. In the H sheet, the Ti-dominant MH(1,2) sites, Fe3+-dominant AP(1) site, and vacant AP(2) sites give ideally Fe3+□Ti2pfu. The MH and AP(1) polyhedra and Si2O7 groups constitute the H sheet. The ideal structural formula of selivanovaite of the form AP2MH2MO4(Si2O7)2(XOM,A)4(XPM,A)4 is Fe3+□Ti2Na□Ti2(Si2O7)2O4(H2O)4. Selivanovaite is a Fe3+-bearing and OH-poor analogue of vigrishinite, ideally Zn□Ti2Na□Ti2(Si2O7)2O2O(OH)(H2O)4. Vigrishinite and selivanovaite are related by the following substitution: O(OH)–vig + H(Zn2+)vig ↔ O(O2–)sel + H(Fe3+)sel. Selivanovaite is a Fe3+-bearing and Na-poor analogue of murmanite, ideally Na2Ti2Na2Ti2(Si2O7)2O4(H2O)4. Murmanite and selivanovaite are related by the following substitution: O(Na+)mur + H(Na+2)mur ↔ O(□)sel + H(Fe3+)sel + H(□)sel. The doubling of the t1 and t2 translations of selivanovaite compared to those of murmanite is due to the ordering of Fe3+ and □ in the H sheet and Na and □ in the O sheet of selivanovaite.
      PubDate: Fri, 27 May 2022 00:00:00 GMT
       
  • Stable and Radiogenic Isotopes in the Exploration for Volcanogenic Massive
           Sulfide Deposits

    • Free pre-print version: Loading...

      Authors: Leybourne MI; Peter JM, Kidder JA, et al.
      Abstract: ABSTRACTRadiogenic (e.g., U-Th-Pb, Rb-Sr, Sm-Nd, Lu-Hf), traditional stable (e.g., S, O, H, C, He, B, and Li), and non-traditional metal stable (e.g., Se, Fe, Zn, Cu, Mo, and Tl) isotopes are increasingly being recognized as powerful geochemical tools for understanding metal and sulfur sources, depositional ages, ambient basin redox, area selection, and vectoring in the exploration for volcanogenic massive sulfide (VMS) deposits.Volcanogenic massive sulfide deposits are metal sulfide deposits that are globally economically important sources of base metals (Zn, Cu, Pb), and, in some deposits, precious (Au, Ag) and by-product critical (e.g., As, Bi, Co, Ge, In, Sn, Sb, Ga, Se, and Te) metals. These deposits are closely associated in space and time with submarine volcanism. Seawater is drawn down into the subsurface, magmatically heated by magma chambers and/or subvolcanic intrusions, and chemically modified during hydrothermal circulation; metals and other solutes in the rocks are leached along the flow path and precipitated at or near the seafloor in response to strong physicochemical gradients between the mineralizing fluid and cold, ambient seawater at the depositional site.Isotope data are not routinely used in mineral exploration due to perceived cost and complexity in interpretation; however, advances in analytical technologies and techniques, refinements to VMS deposit genetic and exploration models, and data integration and reduction algorithms have facilitated the practical potential application of isotope data in exploration for many mineral deposits, including VMS. New technologies have resulted in lower cost, facile analysis, and better understanding of the processes that govern isotopic fractionation, in particular for non-traditional (metal) isotope systems.Radiogenic isotopes are primarily used to date the lithologies (e.g., U-Pb, Ar-Ar) that host the VMS mineralization or the mineralization itself (e.g., Re-Os, Rb-Sr), or hydrothermal alteration products (clays, white micas) (e.g., Ar/Ar). Radiogenic isotopes (e.g., Pb, Sr, Nd, Hf) are also used as tracers to understand metal and solute sources (e.g., mantle versus crust) and processes. Stable isotopes are also used to elucidate metal and solute sources such as seawater, igneous, sedimentary (e.g., S, C, O, H, He), mineralizing processes such as boiling/phase separation (e.g., O, H), and to track hydrothermal fluid-rock interaction (e.g., O). Non-traditional metal isotopes (e.g., Fe, Cu, Zn, Se, Mo, Ni, Hg) have only been applied to studies of VMS deposition for the last decade or so. For these isotope systems, there are still only limited data for ancient VMS. However, most VMS deposits have isotopic values that are essentially similar to mantle values, only rarely showing more extreme fractionation.Several isotope systems (e.g., O, H, C, Sr) are commonly used to recognize and quantify water-rock interactions attendant with hydrothermal alteration associated with VMS mineralizing processes. The most well-studied isotope system in this regard is O, with large isotopic exchange occurring as a function of increasing temperature and water/rock interaction. Strontium isotopes are also useful for understanding alteration around VMS deposits, with potentially significant differences in 87Sr/86Sr as a function of composition of the magma feeding the hydrothermal system, the isotopic composition of extant seawater, and the age and composition of the footwall lithologies.
      PubDate: Fri, 27 May 2022 00:00:00 GMT
       
  • Origin of the Sokoman Iron Formation, Labrador Trough, Canada

    • Free pre-print version: Loading...

      Authors: Zajac I; Peter JM.
      Abstract: ABSTRACTThe Lower Proterozoic, Lake Superior-type Sokoman Iron Formation of the Labrador Trough is one of the world's largest iron formations. It represents a unique, major event in the history of the Trough. Originally a largely irregularly bedded, intraclastic, granular, locally oolitic, conglomeratic iron formation, it is highly variable in its stratigraphy, mineralogy, and textures, which are the consequence of sedimentology, diagenesis, metamorphism, structural deformation, and magmatic overprint. Despite its complexity, the regional characteristics of the iron formation within the 1200 km length of the Labrador Trough indicate three main stratigraphic units, defined by their dominant iron minerals: the lower and upper parts of the formation are characterized by the abundance of iron silicates and carbonates (silicate-carbonate facies), and the middle part is characterized by the dominance of iron oxides (oxide facies). The origin of these lithostratigraphic units of the iron formation is attributed to three main sea-level changes which changed the chemistry (oxidation–reduction potential) and the physical energy (wave and current action) of the sedimentary environment.The vast amount of iron and some of the silica required for deposition of the Sokoman Formation is inferred to be the consequence of intense hydrothermal activity within a major rift created by the eastward extension of the Labrador Trough ca 1.88 Ga. The hydrothermal fluids venting within the rift saturated the deep and likely anoxic sea of the Trough with ferrous iron and some silica which then upwelled onto its oxygenated shallow waters to deposit the iron formation.The end of the processes involved in creating the iron formation ca. 1.82 Ga is attributed to the westward contraction of the Trough induced by the Hudsonian (Trans-Hudson) orogeny, which closed the iron- and silica-generating rift and at the same time ended all magmatic activities and related sedimentation coeval with the deposition of the iron formation.
      PubDate: Fri, 27 May 2022 00:00:00 GMT
       
  • Erratum Genesis of the Jinbaoshan PGE-(Cu)-(Ni) Deposit: Distribution of
           Chalcophile Elements and Platinum-Group Minerals

    • Free pre-print version: Loading...

      Authors: Lu Y; Lesher C, Yang L, et al.
      PubDate: Thu, 19 May 2022 00:00:00 GMT
       
  • Fluorite Mineralization at the Dwyer Mine, Wilberforce Area, Ontario,
           Canada: Microtextural Indications of a Fluor-Calciocarbonatite

    • Free pre-print version: Loading...

      Authors: Martin RF; Schumann D.
      Abstract: ABSTRACTThe ore at the Dwyer fluorite mine, near Wilberforce, Ontario, consists of calcite–fluorite dikes that show clear signs of flowage. Those dikes and the large-scale development of fenites at the expense of a granite–monzonite pluton can only be explained by the existence of a subjacent body of carbonatite. The dikes consist of ribbons of calcite and fluorite and contain subhedral crystals of fluorapatite aligned with the ribbons. The dikes also carry crystals of aegirine-augite, titanite, and bastnäsite-(Ce). Both the fluorapatite and aegirine-augite contain micrometric globules of boundary-layer melt that crystallized in situ to calcite, fluorite, quartz, bastnäsite-(Ce), hematite, and titanite. Fragments of the REE-enriched fenite show signs of incipient rheomorphism at a temperature estimated to be at least 725 °C. The large-scale alkali metasomatism occurred toward the end of the Grenville orogenic cycle, at a time of crustal relaxation, roughly 200 million years after emplacement of a granite–monzonite pluton. By analogy with occurrences elsewhere, it is likely that the carbonatitic melt separated immiscibly from a nepheline syenitic parental melt. Fluor-calciocarbonatitic magmatism likely is genetically linked to the U and Th mineralization in the area and contributed to the unusual geological complexity of the Bancroft–Haliburton region.
      PubDate: Thu, 05 May 2022 00:00:00 GMT
       
  • Donowensite, Ca(H 2 O) 3 Fe 3+ 2 (V 2 O 7 ) 2 , and Mikehowardite, Fe 3+ 4
           (VO 4 ) 4 (H 2 O) 2 ·H 2 O, Two New Vanadium Minerals from the Wilson
           Springs Vanadium Mine, Wilson Springs, Arkansas, USA

    • Free pre-print version: Loading...

      Authors: Kampf AR; Hughes JM, Nash BP, et al.
      Abstract: ABSTRACTDonowensite (IMA2020-067), Ca(H2O)3Fe3+2(V2O7)2, and mikehowardite (IMA2020-068), Fe3+4(VO4)4(H2O)2·H2O, are intimately associated new secondary minerals from the Wilson Springs vanadium mine, Wilson Springs, Arkansas, USA. Donowensite has the following properties: needles up to 1 mm in length; yellow color; orange streak; subadamantine luster; brittle; Mohs hardness 3; splintery fracture; three cleavages ({001} perfect, {100} and {010} very good); density 2.97(2) g/cm3; biaxial (+), α > 1.95, β > 1.95, γ > 1.95; 2V = 72(2)°; moderate r > v dispersion; orientation X ^ b = 7°, Z ≈ c; pleochroism X brown orange, Y orange yellow, Z yellow. Mikehowardite has the following properties: equant prisms up to 0.15 mm in length; very dark brown color; yellow-orange streak; subadamantine luster; Mohs hardness 3½; irregular, stepped fracture; three cleavages ({100} very good, two undetermined good cleavages); density 3.19(2) g/cm3; biaxial with slight pleochroism in shades of brown-orange; Gladstone-Dale nav = 2.034. Electron probe microanalyses provided the empirical formulae Ca0.93Fe3+1.92Mn3+0.01V4.06P0.01O17H6.00 for donowensite and K0.11Ca0.02Fe3+3.78Mn3+0.03V3.67P0.33O18.87H6.18 for mikehowardite. Donowensite is triclinic, P with a = 7.3452(4), b = 9.9291(4), c = 10.0151(7) Å, α = 94.455(7), β = 98.476(7), γ = 100.779(7)°, V = 705.52(7) Å3, and Z = 2. Mikehowardite is triclinic, P with a = 6.6546(17), b = 6.6689(14), c = 9.003(2) Å, α = 76.515(5), β = 84.400(6), γ = 75.058(5)°, V = 375.11(15) Å3, and Z = 1. The structure of donowensite (R1 = 0.0561 for 2615 I > 2σI reflections) contains zig-zag chains of edge-sharing FeO6 octahedra that are linked to one another by V2O7 pyrovanadate groups to form sheets between which are Ca2+ cations and H2O groups. The structure of mikehowardite (R1 = 0.0678 for 1098 I > 2σI reflections) has similarities to the structure of schubnelite. In both mikehowardite and schubnelite, edge-sharing dimers of Fe3+O6 octahedra are linked by distorted VO4 tetrahedra.
      PubDate: Thu, 05 May 2022 00:00:00 GMT
       
  • Zero-Valent-Dominant Pyrochlores: Endmember Formula Calculation and
           Petrogenetic Significance

    • Free pre-print version: Loading...

      Authors: Bhattacharjee S; Dey M, Chakrabarty A, et al.
      Abstract: ABSTRACTThe existing classification of pyrochlore group minerals is essentially based on the dominant valence rule. However, coupled heterovalent-homovalent substitutions at the A-, B-, and Y-sites commonly result in charge-imbalanced endmember formulae. The application of the site total charge (STC) method permits the determination of a charge-balanced endmember. Species names are assigned by using the dominant constituent rule. According to the current IMA nomenclature scheme, some previously established pyrochlore species, such as kalipyrochlore, strontiopyrochlore, bariopyrochlore, plumbopyrochlore, ceriopyrochlore, yttropyrochlore, bismutopyrochlore, and uranpyrochlore, are all grouped as zero-valent-dominant pyrochlores, resulting in the loss of petrogenetic information. In this work, the zero-valent-dominant pyrochlores of the pyrochlore group (sensu stricto) are classified into R+-, R2+-, R3+-, and R4+-pyrochlores where the respective cations (R) are the dominant valencies at the A- and Y-sites (for R+-pyrochlores) after vacancies (□) and H2O. The endmember charge arrangements are determined by the STC method to obtain charge-balanced endmember formulae for all possible zero-valent pyrochlore species. It is recommended that suitable adjectival modifiers be used along with the species name to emphasize the abundance of certain cations, which may or may not be reflected in the endmember formula. This approach would facilitate the usage of pyrochlore group minerals for all practical petrological and exploration purposes. It is considered that pyrochlores with significant A-site vacancies do not necessarily reflect formation in a supergene environment, as such pyrochlores can also form in hydrothermal parageneses.
      PubDate: Thu, 05 May 2022 00:00:00 GMT
       
  • Effects of Grain Size, Cooling Rate, and Sample Preparation on the Phase
           Transition from Protoenstatite to Clinoenstatite

    • Free pre-print version: Loading...

      Authors: Ohi S; Osako T, Miyake A.
      Abstract: ABSTRACTX-ray diffraction experiments were carried out with protoenstatite, chemical composition Mg2Si2O6, in order to clarify the conditions under which protoenstatite can be retained at room temperature. Our results show that grain size, cooling rate, and shear stress during sample preparation clearly affect the transition from protoenstatite to clinoenstatite. Smaller protoenstatite grains were more likely to be retained, and the relationship between the retained volume ratio of the protoenstatite and grain size was statistically consistent with martensitic nucleation. The most protoenstatite was retained in the experiment using a cooling rate of 3 °C/min; the retained volume ratio decreased in experiments with both faster and slower cooling rates. The martensitic transformation of protoenstatite to clinoenstatite is promoted by shear stress caused by a fast cooling rate. Shear stress caused by grinding and polishing also promotes the transformation, but ion milling, used to prepare samples for transmission electron microscope observation, leaves the protoenstatite unchanged. Therefore, samples including protoenstatite should be prepared without producing shear stress so that the protoenstatite can be observed.
      PubDate: Thu, 05 May 2022 00:00:00 GMT
       
  • From Structure Topology to Chemical Composition. XXX. Refinement of the
           Crystal Structure and Chemical Formula of Shkatulkalite, Na 2 Nb 2 Na 3
           Ti(Si 2 O 7 ) 2 O 2 (FO)(H 2 O) 4 (H 2 O) 3 , a Lamprophyllite-Group
           (Seidozerite Supergroup) TS-Block Mineral from the Lovozero Massif, Kola
           Peninsula, Russia

    • Free pre-print version: Loading...

      Authors: Sokolova E; Day MC, Hawthorne FC, et al.
      Abstract: ABSTRACTShkatulkalite, ideally Na5TiNb2(Si2O7)2O3F(H2O)7, is a lamprophyllite-group (seidozerite supergroup) TS-block mineral from the Lovozero massif, Kola Peninsula, Russia. The crystal structure of shkatulkalite was refined as triclinic, space group P, a 5.464(1), b 7.161(1), c 15.573(1) Å, α 90.00(3), β 95.75(3), γ 90.00(3)°, V 606.3(4) Å3, R1 = 7.26%. The previously given chemical analysis has been modified to better fit the crystal structure: Nb2O5 24.15, TiO2 11.35, SiO2 27.22, BaO 1.15, SrO 2.20, MnO 1.68, CaO 0.46, K2O 0.29, Na2O 14.78, H2O 15.27, F 1.61, O = F −0.68, sum 99.48 wt.%; H2O was determined from structure-refinement results. The empirical formula was calculated on 25.27 (O + F) apfu (in accord with the crystal structure): (Na1.40Sr0.19Ba0.07K0.05)Σ1.71(Na2.86Mn0.10Ca0.07)Σ3.03(Nb1.62Ti1.27Mn0.11)Σ3Si4.03O24.52H15.11F0.75, Z = 1. The ideal structural formula is as follows: Na2Nb2Na3Ti(Si2O7)2O2(FO)(H2O)4(H2O)3. The crystal structure of shkatulkalite [basic structure type B5(LG)] is a combination of a TS (titanium-silicate) block and an I (intermediate) block. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for the lamprophyllite group where Ti (+ Nb + Fe3+ + Mg) = 3 apfu. The O sheet is composed of Ti-dominant MO(1) and Na-dominant MO(2,3) octahedra. In the H sheet in shkatulkalite, Si2O7 groups link to Nb-dominant MH octahedra. The AP site occurs in the plane of the H sheet and splits into AP(1) and AP(2) sites, occupied by Na at 70% and Sr (less Ba and K) at 11%. The I block consists of H2O groups. The I block of shkatulkalite is topologically identical to those in the derivative structures of kazanskyite and nechelyustovite. The structure of the lamprophyllite-group mineral shkatulkalite has a counterpart structure in the murmanite group (Ti = 4 apfu): kolskyite, ideally Na2CaTi4(Si2O7)2O4(H2O)7 [basic structure type B7(MG)]: the two structures have TS blocks of different topology and similar I blocks, mainly occupied by H2O groups.
      PubDate: Tue, 19 Apr 2022 00:00:00 GMT
       
  • The Crystal Structure of Malhmoodite from Custer, South Dakota, USA

    • Free pre-print version: Loading...

      Authors: Yang H; Gu X, Loomis T, et al.
      Abstract: ABSTRACTAn occurrence of malhmoodite, Fe2+Zr(PO4)2·4H2O, from the Scott's Rose Quartz mine, Custer County, South Dakota, USA, has been identified. It occurs as divergent groups of yellowish, flat-lying platy crystals on football-size masses of altered löllingite with scorodite, parasymplesite, karibibite, schneiderhöhnite, kahlerite, and zircon. An electron probe microanalysis of malhmoodite yielded an empirical formula (based on 12 O apfu) of Fe1.06(Zr1.10Hf0.03)Σ1.13[(P0.93As0.01)Σ0.94O4]2·4H2O.Single-crystal X-ray structure analysis shows that malhmoodite is the Fe-analogue of zigrasite, MgZr(PO4)2·4H2O. Malhmoodite is triclinic with space group P and unit-cell parameters a = 5.31200(10), b = 9.3419(3), c = 9.7062(3) Å, α = 97.6111(13), β = 91.9796(11), γ = 90.3628(12)°, V = 477.10(2) Å3, Z = 2, in contrast to the previously reported monoclinic symmetry with space group P21/c and unit-cell parameters a = 9.12(2), b = 5.42(1), c = 19.17(2) Å, β = 94.8(1)°, V = 944.26 Å3, Z = 4. The crystal structure of malhmoodite is characterized by sheets composed of ZrO6 octahedra sharing all vertices with PO4 tetrahedra. These sheets are parallel to (001) and are joined together by the FeO2(H2O)4 octahedra. The structure determination of malhmoodite, along with that of zigrasite, warrants a re-investigation of synthetic compounds M2+Zr(PO4)2·4H2O (M = Mn, Ni, Co, Cu, or Zn) that have been assumed previously to be monoclinic.
      PubDate: Tue, 19 Apr 2022 00:00:00 GMT
       
  • Crystal Structure of Tengchongite with a Revised Chemical Formula Ca(UO 2
           ) 6 (MoO 4 OH) 2 O 2 (OH) 4 ·9H 2 O

    • Free pre-print version: Loading...

      Authors: Li T; Fan G, Ge X, et al.
      Abstract: ABSTRACTTengchongite, a uranyl molybdate mineral from Tengchong County, Yunnan Province, China, was originally described as orthorhombic, with space group A2122, unit-cell parameters a = 15.616(4) Å, b = 13.043(6) Å, c = 17.716(14) Å, V = 3608 Å3, and an ideal chemistry CaO·6UO2·2MO3·12H2O. Its ideal chemical formula is given as Ca(UO2)6(MoO4)2O5·12H2O in the current IMA-CNMNC List of Mineral Names. Tengchongite is the only mineral with a U:Mo ratio of 3:1, the second-highest ratio of all natural and synthetic uranyl molybdate materials, but its crystal structure remained undetermined until now. This study reports the structure determination of tengchongite from the type sample and a revision of its chemical formula to Ca(UO2)6(MoO4OH)2O2(OH)4·9H2O. Tengchongite is orthorhombic, with space group C2221, Z = 4, a = 13.0866(8) Å, b = 17.6794(12) Å, c = 15.6800(9) Å, and V = 3627.8(4) Å3. Its crystal structure was refined from single-crystal X-ray diffraction data to R1 = 0.0323 for 6055 unique observed reflections. The fundamental building blocks of the tengchongite structure are sheets consisting of six-membered clusters of edge-sharing UO7 pentagonal bipyramids, which are connected by sharing vertices among them, as well as edges and vertices with MoO5 trigonal bipyramids. These sheets, parallel to [010], are linked together by Ca2+ and H2O groups. Tengchongite represents a new type of structural connectivity between U- and Mo-polyhedra for uranyl molybdate minerals.
      PubDate: Mon, 18 Apr 2022 00:00:00 GMT
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.235.140.84
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-