scholarly journals Chemical Characteristics of Freshwater and Saltwater Natural and Cultured Pearls from Different Bivalves

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 357 ◽  
Author(s):  
Stefanos Karampelas ◽  
Fatima Mohamed ◽  
Hasan Abdulla ◽  
Fatema Almahmood ◽  
Latifa Flamarzi ◽  
...  

The present study applied Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) on a large number of natural and cultured pearls from saltwater and freshwater environments, which revealed that freshwater (natural and cultured) pearls contain relatively higher quantities of manganese (Mn) and barium (Ba) and lower sodium (Na), magnesium (Mg) and strontium (Sr) than saltwater (natural and cultured) pearls. A few correlations between the host animal’s species and chemical elements were found; some samples from Pinctada maxima (P. maxima) are the only studied saltwater samples with 55Mn >20 ppmw, while some P. radiata are the only studied saltwater samples with 24Mg <65 ppmw and some of the P. imbricata are the only studied saltwater samples with 137Ba >4.5 ppmw. X-ray luminescence reactions of the studied samples has confirmed a correlation between its yellow-green intensity and manganese content in aragonite, where the higher Mn2+ content, the more intense the yellow-green luminescence becomes. Luminescence intensity in some cases is lower even if manganese increases, either because of pigments or because of manganese self-quenching. X-ray luminescence can be applied in most cases to separate saltwater from freshwater samples; only samples with low manganese content (55Mn <50 ppmw) might be challenging to identify. One of the studied natural freshwater pearls contained vaterite sections which react by turning orange under X-ray due to a different coordination of Mn2+ in vaterite than that in aragonite.

2015 ◽  
Vol 12 (6) ◽  
pp. 551-562 ◽  
Author(s):  
Yue Yuan ◽  
Yanheng Li ◽  
Jingsen Fan

In this paper, the geochemical characteristics of the trace elements of the No. 6 coal seam from Tanggongta mine, Jungar Coalfield, were studied using the methods of an energydispersive X-ray spectrometer (SEM-EDX) analysis, X-ray powder diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometric (XRF) techniques. The content of sulfur ranges from 0.09% to 2.83% (1.09% on average). The ash is from 11.70% to 31.47% (20.72% on average), and the moisture is from 2.72% to 6.82% (4.72% on average). The main minerals are kaolinite, carbonate minerals and pyrite. Compared with the average values of Chinese coal, the contents of Ga, Cd, Tl, Li, Sr, and Ag are high. Compared with the values of world coal, Li and Sr are found at high levels. The distribution mode of the REE shows that LREE is concentrated, but HREE is relatively low. The Yinshan Oldland should be the most likely source of the coal’s Li. The bauxite of the Benxi formation could be another source of the coal’s Li in the NE Jungar Coalfield.


2007 ◽  
Vol 361-363 ◽  
pp. 737-740 ◽  
Author(s):  
M.M. Sovar ◽  
C. Ducu ◽  
D. Iordachescu ◽  
Ioana Demetrescu

The present work is focused on the stability of bioactivated CoCr alloy in biological environment (buffered saline solution (PBS), lactic acid, citric acid). The chemical and electrochemical deposition was characterized by electrochemical methods (open circuit potential, cyclic voltametry), scanning electronic microscope (SEM), x-ray diffractometer (XRD), inductively coupled plasma/mass spectrometry (ICP/MS) and citotoxicity test. The results prove a good electrochemical stability in all cases.


Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 766
Author(s):  
Uxue Sanchez-Garmendia ◽  
Javier G. Iñañez ◽  
Gorka Arana

Ancient ceramics recovered after a long burial period have probably undergone several alterations and contaminations, introducing a chemical variability, affecting the ceramic’s natural variability. That is, the chemical and the mineralogical compositions of the ceramic pastes after their deposition will not be the same as they originally were. Therefore, it is known that the alteration and contamination processes, and the discrimination of some elements, should be considered when studying the ceramics to avoid incorrect interpretations about their provenance, technology and the use of the artefact, as well as its proper preservation. In the present work, the authors performed an experimental approach in order to study the alterations and contaminations that occurred in 60 ceramic cylinders buried in two different underwater environments. Once the pieces were taken out from the water environments, they were characterized by a multi-analytical approach. For this purpose, inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), scanning electron microscopy–energy dispersive spectrometry (SEM–EDS) and Raman spectroscopy were used. Newly formed minerals of different forms have been identified, with different crystallization grades. Some examples are the needles, flakes, sponges and long and short prisms composed of several elements such as Ca, F, S and O.


Author(s):  
M. P. Zykova ◽  
V. Yu. Krolevetskaya ◽  
E. N. Mozhevitina ◽  
E. M. Gavrishchuk ◽  
I. Сh. Avetissov

The problem of obtaining crystalline ZnSe doped with d-elements for obtaining high-efficiency laser materials with characteristics in a wide IR range don’t possible successfully solved without reliable data on phase equilibrium and solubility of the components entering the system. The theoretical and experimental analysis of the three-component Zn—Se—Fe system for obtaining new fundamental information on phase using X-ray analysis (XRD) and inductively coupled plasma mass spectrometry (ICP-MS) was carried out. New experimental data of isothermal annealing in the ternary Zn—Se—Fe system at the temperatures 730 K (I, II), 814 K (III, IV), 1073 K (V), as well as information on Fe solubility in bi- and monovariant conditions by X-ray studies have shown the existence of the coexistence of the following phases: Fe3Zn10-Fe11Zn40-Zn-ZnSe (I), ZnSe-FeSe2-Fe7Se8 (II), ZnSe-Fe3Zn10-Fe (III), FeSe2-Fe7Se8-Se (IV), ZnSe-FeSe- Fe3Se4 (V), ZnSe-FeSe (VI) and confirmed the reliability of theoretical isothermal sections.


Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1006 ◽  
Author(s):  
Krzysztof Kupczak ◽  
Rafał Warchulski ◽  
Mateusz Dulski ◽  
Dorota Środek

Slags from the historic metallurgy of Zn-Pb ores are known for unique chemical and phase compositions. The oxides, silicates, aluminosilicates, and amorphous phases present therein often contain in the structure elements that are rare in natural conditions, such as Zn, Pb, As. The study focuses on processes occurring on the contact of the melted batch and the refractory materials that build the furnace, which lead to the formation of these phases. To describe them, chemical (X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS)) and petrological ((X-ray diffraction (XRD), electron probe micro-analyses (EPMA), Raman spectroscopy) analyses were performed on refractory material, slag, and contact of both. Two main types of reactions have been distinguished: gas/fluid- refractories and liquid- refractories. The first of them enrich the refractories with elements that migrate with the gas (Pb, K, Na, As, Zn) and transport the components building it (Fe, Mg, Ca) inward. Reactions between melted batch and refractory materials through gravitational differentiation and the melting of refractories lead to the formation of an aluminosilicate liquid with a high content of heavy elements. Cooling of this melt causes crystallization of minerals characteristic for slag, but with a modified composition, such as Fe-rich pyroxenes, Pb-rich K-feldspar, or PbO-As2O3-SiO2 glass.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 724
Author(s):  
Giuseppa Di Bella ◽  
Angela Giorgia Potortì ◽  
Asma Beltifa ◽  
Hedi Ben Mansour ◽  
Vincenzo Nava ◽  
...  

The concentrations of 19 chemical elements have been determined in 36 honey samples of different botanical (wildflower, eucalyptus, eucalyptus red flowers, prickly pears, lemon blossom, thyme, almond, rosemary and jujube) honeys from the three geographical areas of Tunisia (Sidi Bouzid, Nabeul and Sfax) using inductively coupled plasma mass spectrometry (ICP-MS). The aim of this work was to use the multielement analysis together with chemometric tools to verify the botanical and the geographical origin of honeys. The correlation on the basis of mineral element content between the honey samples and their botanical and/or geographical origins was in some measure achieved. The data collected on the samples were also used to evaluate the nutritional quality and the potential health risks associated with elements via consumption of the Tunisian honey. According to the results obtained, the intake of essential elements was small, and the potential health risks associated with toxic or potentially toxic elements via consumption of this food were overall insignificant.


EKSPLORIUM ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 101 ◽  
Author(s):  
Ronaldo Irzon ◽  
Baharuddin Abdullah

ABSTRACTSoutheast Sulawesi is crosscutted by Lasolo Fault into two geological provinces: Tinondo and Hialu. Tinondo Geological Province is occupied largely by Ophiolite Complex in the northern part of Southeast Arm of Sulawesi. No study was conducted in relation to the geochemistry composition of Ophiolite Complex in North Konawe Regency. The aim of this study is to describe the ultramafic rock of the Ophiolite Complex in North Konawe Regency using field, geochemical, and petrographical analysis. Megascopically, the selected nine samples are described as greyish to blackish and fine to medium grains ultramafic rocks, which consist of pyroxene and olivine. Microscope, X-Ray Fluorescence (XRF), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) devices were used to obtain both petrography and geochemistry data. Major oxides data confirm that the selected samples are classified into ultramafic rocks as SiO2, MgO, and Fe2O3T are the most abundant oxides. The studied samples presumably came from arc tholeiitic environment tectonic setting. Ultramafic rocks often contain promising economic metals whereas the average numbers of Ni, Mn, Cr, and Co of this study are 2,675; 1,074; 2,386; and 117 ppm respectively. The rocks are generally enriched in high field strength elements whilst rare earth elements value are low, ranging from 2.11 to 7.10 ppm. Microscopically, samples can be classified into three groups: olivine-hornblende pyroxenite, lherzolite, and olivine websterite. Geochemical data describes more about the discriminant analysis of the groups. ABSTRAKWilayah Sulawesi Tenggara dipotong oleh Sesar Lasolo yang membagi daerah ini menjadi dua lajur: Tinondo dan Hialu. Lajur Tinondo diisi sebagian besar oleh Komplek Ophiolit, yang berada di bagian utara dari Lengan Tenggara Sulawesi. Belum ada studi yang terfokus kepada kandungan geokimia Komplek Ophiolit tersebut di wilayah Kabupaten Konawe Utara.Studi ini bertujuan untuk mempelajari karakter batuan ultramafik dari Komplek Ophiolit di Kabupaten Konawe Utara melalui kegiatan lapangan, analisis geokimia, dan analisis petrografi. Secara megaskopis, sembilan contoh batuan terpilih teridentifikasi sebagai batuan ultramafik berwarna kelabu hingga hitam, berukuran butir sedang hingga halus, dan mengandung piroksen maupun olivine. Perangkat mikroskop, X-Ray Fluorescence (XRF), dan Inductively Coupled Plasma Mass Spectrometry (ICP-MS) dimanfaatkan untuk memperoleh data geokimia maupun mikroskopis. Data oksida utama mengklasifikasikan contoh terpilih ke dalam batuan utramafik dengan SiO2, MgO, dan Fe2O3T sebagai oksida dengan kelimpahan tertinggi. Contoh terpilih mungkin terbentuk pada lingkungan busur tektonik tholeitik. Batuan ultramafik sering mengandung logam ekonomis dengan kadar rata-rata Ni, Mn, Cr, dan Co pada studi ini adalah: 2.675, 1.074, 2.386, dan 117 ppm secara berurutan. Batuan telah mengalami pengayaan unsur high field strength elements meskipun dengan kadar unsur tanah jarang yang rendah, berkisar dari 2,11 hingga 7,10 ppm. Secara petrografi, batuan terpilih dapat dibagi menjadi tiga kelompok: olivine-hornblende pyroxenite, lherzolite, and olivine websterite. Data geokimia menjelaskan lebih lanjut mengenai perbedaan dari kelompok-kelompok tersebut.


Antiquity ◽  
2017 ◽  
Vol 91 (356) ◽  
Author(s):  
Clive Bonsall ◽  
Nedko Elenski ◽  
Georgi Ganecovski ◽  
Maria Gurova ◽  
Georgi Ivanov ◽  
...  

Portable energy-dispersive X-ray fluorescence (pXRF) has become a widely used tool for the chemical characterisation (source identification) of obsidian found in archaeological contexts. While laboratory techniques such as neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP-MS) can analyse more elements and have lower detection limits, pXRF can provide quantitative data of sufficient resolution to be able to match obsidian artefacts with their volcanic sources. At the same time, pXRF offers several advantages for obsidian research: (i) it can be deployed ‘in the field’ (i.e. on site or in a museum) without the need to bring samples back to a laboratory for analysis; (ii) information on elemental composition can be obtained relatively quickly; and (iii) measurements require no special preparation of samples and cause no visible damage to materials.


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