scholarly journals Raman spectroscopy of the minerals boléite，cumengéite， diaboléte and phosgenite — implications for the analysis of cosmetics of antiquity

2003 ◽  
Vol 67 (1) ◽  
pp. 103-111 ◽  
Author(s):  
R. L. Frost ◽  
P. A. Williams ◽  
W. Martens
Keyword(s):  
Molecular Structure ◽  
Raman Spectroscopy ◽  
Molecular Structures ◽  
Carbonate Mineral ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Secondary Mineral Formation ◽  
Bending Modes ◽  
Wavenumber Region ◽  
Deformation Modes

AbstractThe application of Raman spectroscopy to the study of the mixed cationic Pb-Cu and Pb-Cu-Ag minerals: boleite, cumengeite and diaboleite has enabled their molecular structures to be compared. Each of these three minerals shows different hydroxyl-stretching vibrational patterns, but some similarity exists in the Raman spectra of the hydroxyl-deformation modes. The low-wavenumber region is characterized by the bands assigned to the cation-chloride stretching and bending modes. Phosgenite is also a mixed chloride-carbonate mineral and a comparison is made with the molecular structure of the aforementioned minerals. Raman spectroscopy lends itself to the study of these types of minerals in complex mineral systems of secondary mineral formation.

scholarly journals A record of Neogene seawater <i>δ</i><sup>11</sup>B reconstructed from paired <i>δ</i><sup>11</sup>B analyses on benthic and planktic foraminifera

2017 ◽  
Vol 13 (2) ◽  
pp. 149-170 ◽  
Author(s):  
Rosanna Greenop ◽  
Mathis P. Hain ◽  
Sindia M. Sosdian ◽  
Kevin I. C. Oliver ◽  
Philip Goodwin ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Middle Miocene ◽  
Isotope Composition ◽  
Boron Isotope ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Cycle Model ◽  
Planktic Foraminifera ◽  
Carbon Cycle Model ◽  
Secondary Mineral Formation

Abstract. The boron isotope composition (δ11B) of foraminiferal calcite reflects the pH and the boron isotope composition of the seawater the foraminifer grew in. For pH reconstructions, the δ11B of seawater must therefore be known, but information on this parameter is limited. Here we reconstruct Neogene seawater δ11B based on the δ11B difference between paired measurements of planktic and benthic foraminifera and an estimate of the coeval water column pH gradient from their δ13C values. Carbon cycle model simulations underscore that the ΔpH–Δδ13C relationship is relatively insensitive to ocean and carbon cycle changes, validating our approach. Our reconstructions suggest that δ11Bsw was  ∼  37.5 ‰ during the early and middle Miocene (roughly 23–12 Ma) and rapidly increased during the late Miocene (between 12 and 5 Ma) towards the modern value of 39.61 ‰. Strikingly, this pattern is similar to the evolution of the seawater isotope composition of Mg, Li and Ca, suggesting a common forcing mechanism. Based on the observed direction of change, we hypothesize that an increase in secondary mineral formation during continental weathering affected the isotope composition of riverine input to the ocean since 14 Ma.

The behaviour of Li and Mg isotopes during primary phase dissolution and secondary mineral formation in basalt

2010 ◽  
Vol 74 (18) ◽  
pp. 5259-5279 ◽  
Author(s):  
Josh Wimpenny ◽  
Sigurður R. Gíslason ◽  
Rachael H. James ◽  
Abdelmouhcine Gannoun ◽  
Philip A.E. Pogge Von Strandmann ◽  
...  
Keyword(s):  
Primary Phase ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Phase Dissolution ◽  
Mg Isotopes ◽  
Secondary Mineral Formation

Studies of secondary mineral formation in the PbO-H2O-HC1 system

1992 ◽  
Vol 56 (382) ◽  
pp. 53-65 ◽  
Author(s):  
R. Edwards ◽  
R. D. Gillard ◽  
P. A. Williams ◽  
A. M. Pollard
Keyword(s):  
Stability Constant ◽  
Metastable Phase ◽  
Metastable Phases ◽  
Corrosion Products ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Solid Phases ◽  
Secondary Mineral Formation

AbstractNew stability constant data are presented for the minerals blixite, mendipite and the compound Pb7O6Cl2.2H2O at 298.2 K and P = 105 Pa. Mendipite is in fact a metastable phase at this temperature, being thermodynamically stable under the appropriate conditions at temperatures above about 29°C Kinetic influences are of some significance with respect to the sequence of formation of solid phases in the PbO-HCl-HH2O system, and these have been elucidated for some important reactions. Penfieldite and fiedlerite appear to be metastable phases at all temperatures at 105 Pa. The results have been used to reassess the conditions of formation of the lead(II) oxy- and hydroxychloride phases that are known to form as minerals and as corrosion products of lead-containing artefacts. The effect of CO2 on the system is also described.

scholarly journals Investigations of Raman spectra Part I—The Raman spectra of sulphuric, nitric, and nitrosylsulphuric acids

1935 ◽  
Vol 149 (867) ◽  
pp. 327-340 ◽  
Keyword(s):  
Molecular Structure ◽  
Raman Spectroscopy ◽  
Sulphuric Acid ◽  
Raman Spectra ◽  
Intermediate Product ◽  
Empirical Formula ◽  
Molecular Structures ◽  
Chemical Data ◽  
Molecular Configuration

Apart from the large amount of research undertaken to prove the existence of nitrosylsulphuric acid as an intermediate product in the manufacture of sulphuric acid by the lead chamber process, many researches have been made to determine the composition and constitution of the molecule. Whilst it is universally agreed that the empirical formula is HNSO 5 there is diversity of opinion on the molecular configuration and four different molecular structures are to be found in the literature. The present work was undertaken in an endeavour to clarify the position and in the hope that, by correlating the results obtained by Raman spectroscopy with the large amount of existing chemical data, more definite conclusion could be drawn regarding the molecular structure.

scholarly journals Influence of Calcium Ion and pH on Oxidation Rates and Secondary Mineral Formation on Pyrite Surface

2020 ◽  
Author(s):  
Jifeng Xue ◽  
Sana Ishida ◽  
Tatsuya Kato ◽  
Shigeshi Fuchida ◽  
Shigeto Kuroiwa ◽  
...  
Keyword(s):  
Calcium Ion ◽  
Pyrite Surface ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Oxidation Rates ◽  
Secondary Mineral Formation
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