A multimethodic approach for the characterization of manganiceladonite, a new member of the celadonite family from Cerchiara mine, Eastern Liguria, Italy

2017 ◽  
Vol 81 (1) ◽  
pp. 167-173
Author(s):  
G. O. Lepore ◽  
L. Bindi ◽  
F. Di Benedetto ◽  
E. Mugnaioli ◽  
C. Viti ◽  
...  

AbstractIn the manganesiferous ores associated with the metacherts of the ophiolitic sequences at the Cerchiara mine, Eastern Liguria (Italy), a new Mn-bearing mineral belonging to the mica group has been recently found and characterized. High resolution transmission electron microscopy and electron diffraction tomography studies confirm that the mineral belongs to the mica group. Unit-cell parameters from the powder diffraction pattern are:a= 5.149(1),b= 8.915(1),c= 10.304(1) Å, β = 102.03(1)°, space groupC2 orC2/m. On the basis of the electron paramagnetic resonance spectroscopic results, the Mn4+content represents a very subordinate fraction of the total Mn, the remaining occurring as Mn3+. The Raman spectrum clearly indicates the presence of OH groups in the structure. Laser-ablation inductively-coupled-plasma mass-spectrometry measurements assess the presence of considerable amounts of Li.Assuming all Mn as Mn3+and 22 negative charges, the empirical formula can be expressed as: (K0.83□0.17)(Mn1.143+Mg0.80Li0.20Fe0.023+)(Si3.89Al0.10)O10[(OH)1.92F0.08] with the sum of the octahedral cations indicating a 'transitional' character between a di- and a tri-octahedral structure. This formula corresponds ideally to the Mn3+analogue of celadonite, thus expanding the range of solid solution in the celadonite family. The ideal end-member formula KMn3+MgSi4O10(OH)2can be easily related to celadonite by the homovalent substitutionVIMn3+→VIFe3+. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association, (IMA 2015-052).

Archaeometry ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 35-46 ◽  
Author(s):  
D. J. Kennett ◽  
A. J. Anderson ◽  
M. J. Cruz ◽  
G. R. Clark ◽  
G. R. Summerhayes

2018 ◽  
Vol 82 (5) ◽  
pp. 1049-1055 ◽  
Author(s):  
Daniel Atencio ◽  
Marcelo B. Andrade ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Matteo Zoppi ◽  
...  

ABSTRACTThis study presents a complete characterization of kenoplumbomicrolite, (Pb,□)2Ta2O6[□,(OH),O], occurring in an amazonite pegmatite from Ploskaya Mountain, Western Keivy Massif, Kola Peninsula, Murmanskaja Oblast, Northern Region, Russia.Kenoplumbomicrolite occurs in yellowish brown octahedral, cuboctahedral and massive crystals, up to 20 cm, has a white streak, a greasy lustre and is translucent. The Mohs hardness is ~6. Attempts to measure density (7.310–7.832 g/cm3) were affected by the ubiquitous presence of uraninite inclusions. Reflectance values were measured in air and immersed in oil. Kenoplumbocrolite is optically isotropic. The empirical formula is (Pb1.30□0.30Ca0.29Na0.08U0.03)Σ2.00(Ta0.82Nb0.62Si0.23Sn4+0.15Ti0.07Fe3+0.10Al0.01)Σ2.00O6[□0.52(OH)0.25O0.23]Σ1.00 (from the crystal used for the structural study) and (Pb1.33□0.66Mn0.01)Σ2.00(Ta0.87Nb0.72Sn4+0.18Fe3+0.11W0.08Ti0.04)Σ2.00O6[□0.80(OH)0.10O0.10]Σ1.00 (average including additional fragments). The mineral is cubic, space group Fd$\overline 3 $m. The unit-cell parameters refined from powder X-ray diffraction data are a = 10.575(2) Å and V = 1182.6(8) Å3, which are in accord with those obtained previously from a single crystal of a = 10.571(1) Å, V = 1181.3(2) Å3 and Z = 8. The mineral description and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2015-007a).


Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1236
Author(s):  
Sylwia Svorová Pawełkowicz ◽  
Barbara Wagner ◽  
Jakub Kotowski ◽  
Grażyna Zofia Żukowska ◽  
Bożena Gołębiowska ◽  
...  

Impurities in paint layers executed with green and blue copper pigments, although relatively common, have been studied only little to date. Yet, their proper identification is a powerful tool for classification of paintings, and, potentially, for future provenance studies. In this paper, we present analyses of copper pigments layers from wall paintings situated in the vicinity of copper ore deposits (the palace in Kielce, the palace in Ciechanowice, and the parish church in Chotków) located within the contemporary borders of Poland. We compare the results with the analyses of copper minerals from three deposits, two local, and one historically important for the supply of copper in Europe, i.e., Miedzianka in the Holy Cross Mountains, Miedzianka in the Sudetes, and, as a reference, Špania Dolina in the Slovakian Low Tatra. Optical (OM) and electron microscopy (SEM-EDS), Raman spectroscopy, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been used for a detailed investigation of the minute grains. Special attention has been devoted to antimony and nickel phases, as more unusual than the commonly described iron oxides. Analyses of minerals from the deposits helped to interpret the results obtained from the paint samples. For the first time, quantitative analyses of copper pigments’ impurities have been described.


2020 ◽  
Vol 35 (3) ◽  
pp. 455-460 ◽  
Author(s):  
Eduardo Bolea-Fernandez ◽  
Ana Rua-Ibarz ◽  
Milica Velimirovic ◽  
Kristof Tirez ◽  
Frank Vanhaecke

The occurrence of microplastics (MPs) in the environment is a matter of increasing concern. In this work, it has been shown for the first time that ICP-MS operated in single-event mode can be used for the characterization of MPs relying on their C content.


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