Analyzing Raman - Infrared spectral correlation in the recently found meteorite Csátalja

Shock-induced olivine-ringwoodite and plagioclase-maskelynite transformations in Bursa L6 chondrite: A Raman and ATR-FTIR spectroscopic study

Olivine-ringwoodite and plagioclase-maskelynite transformation mechanisms in the Bursa L6 chondrite were determined by Raman and Attenuated Total Reflectance (ATR)-Fourier Transform Infrared (FTIR) spectroscopic techniques. Forsterite composition was estimated to be 75% by using Raman and IR correlation data. Possible high impact shock pressure for Bursa meteorite was found to be at least 64.9 GPa. Besides, based on the olivine doublet (820 and 852 cm^-1) and Full Width at Half Maximum data (~20 and ~60 cm^-1, respectively) for maskelynite (509 and 580 cm^-1) observed in the Raman spectrum, we assigned the shock stage of this meteorite as at least S5, for the first time. Moreover, previously reported hypervelocity impact experiments also supported this assignment.

A scoping study of component-specific toxicity of mercury in urban road dusts from three international locations

This scoping study presents an investigation of the total and bioaccessible mercury concentrations in road dust (RD) from three international urban sites, where a one-off sampling campaign was conducted at each. This was done to address the hypothesis that the matrix in which mercury is found influences its ability to become accessible to the body once inhaled. For that purpose, the samples were analysed for total and pulmonary bioaccessible mercury and the data compared to the chemical structure of individual particles by SEM. The results obtained from this study suggest that a high mercury content does not necessarily equate to high bioaccessibility, a phenomenon which could be ascribed to the chemical character of the individual particles. It was found that the Manchester samples contained more pulmonary soluble mercury species (as determined by elemental associations of Hg and Cl) in comparison to the other two samples, Curitiba, Brazil, and Johannesburg, South Africa. This finding ultimately underlines the necessity to conduct a site-specific in-depth analysis of RD, to determine the concentration, chemical structure and molecular speciation of the materials within the complex matrix of RD. Therefore, rather than simply assuming that higher bulk concentrations equate to more significant potential human health concerns, the leaching potential of the metal/element in its specific form (for example as a mineral) should be ascertained. The importance of individual particle behaviour in the determination of human health risk is therefore highlighted.

Spatially-resolved mineral identification and depth profiling on chondrules from the primitive chondrite Elephant Moraine 14017 with confocal Raman spectroscopy

Confocal Raman spectroscopy is effective in unveiling structures of minerals without destruction from surface to certain depth. In this study, we introduce an application of confocal Raman spectroscopy on minerals in a primitive chondritic meteorite. The experimental lateral resolution on silicate minerals in this study is ~1.0 μm. Raman spectrum of mesostasis in a named "Tear Drop" chondrule, a spherule object from a primitive chondrite, of Elephant Moraine 14017 (EET 14017) shows a broad feature indicating amorphous phase, which is a common characteristic of primitive chondrule mesostasis. Weak intensities of 825 and 858 cm^-1 peaks were observed in the glassy mesostasis, probably originated from olivine below the surface. A plagioclase-rich chondrule (PRC-1) of EET 14017 was investigated with Raman spectroscopy, which contains two different occurrences of plagioclase: lath-shaped and interstitial grains. The strong intensity of 488 and 505 cm^-1 (plagioclase) and weak intensity of 461 cm^-1 band were observed on the lath-shaped plagioclase. The weak 461 cm^-1 peak from the plagioclase is probably from the subsurface quartz. Raman spectrum of interstital plagioclase in PRC-1 shows 488 and 505 cm^-1 bands and weak pyroxene bands. Depth profiling conducted on the interstitial plagioclase clearly shows that pyroxene exists below the surface. High-lateral resolution and well-resolved depth profiling with the confocal Raman spectroscopy allows us to identify tiny grains and investigate hidden phases underneath the surface without destruction of extraterrestrial materials.