Search

The study was carried out in order to estimate reliability of EDS analysis for identification of various naturaland anthropogenic metal-bearing phases in polished and rough particle samples of stream sediments. For thispurpose, the accuracy and precision of EDS analysis were assessed. Results of the precision measurements showedthat the overall relative standard deviation of EDS measurements was 8 % for polished samples and 24 % for roughparticle samples and was within acceptable limits for most of major elements and some of the elements present inminor or trace contents in the analysed metal-bearing phases. The random analytical fluctuations were considerednegligible and phase compositions could be determined with sufficient reliability in individual grains of each phase.The overall average relative error for all elements amounted to about 12 %, which was within acceptable limits foraccuracy in EDS analysis of polished samples. Chemical formulae and identification of mineral species of metalbearingphases were thus calculated from atomic ratios between constituent elements with sufficient accuracy. Acomparison between EDS measurements in polished and rough particle samples using the Welch’s t-test showedthat about 38 % of studied metal-bearing phases could be identified with sufficient reliability by EDS analysis ofrough particle samples. The results of this study demonstrated that elemental composition of metal-bearing phasesin polished and rough particle samples was mostly determined with sufficient precision and accuracy using EDSanalyses.

The composition of the well-preserved fusion crust of the meteorite Jesenice was characterised by means ofoptical and scanning electron microscopy (SEM). The SEM investigations revealed three structurally distinct layerswithin the crust. The features of the first layer on the surface are precipitates, enriched in metal elements (iron,nickel), and the partial melting of silicate grains, which continues deeper into the second layer. The second layerbeneath has veins with a heterogeneous composition that indicates a different source of melting minerals. The thirdlayer, which is located deeper within the fusion crust, has not undergone any structural changes and its features aresimilar to the interior of the meteorite. This is additionally confirmed by the presence of cracks, which are a consequenceof shock metamorphism, and irregularly shaped metal and sulphide grains. The structural changes of thethin fusion crust on the surface of this stony meteorite indicate high temperatures (more than 1500 °C) accompaniedby high pressures.

The study was carried out in order to estimate reliability of EDS analysis for identification of various natural and anthropogenic metal-bearing phases in polished and rough particle samples of stream sediments. For this purpose, the accuracy and precision of EDS analysis were assessed. Results of the precision measurements showed that the overall relative standard deviation of EDS measurements was 8 % for polished samples and 24 % for rough particle samples and was within acceptable limits for most of major elements and some of the elements present in minor or trace contents in the analysed metal-bearing phases. The random analytical fluctuations were considered negligible and phase compositions could be determined with sufficient reliability in individual grains of each phase. The overall average relative error for all elements amounted to about 12 %, which was within acceptable limits for accuracy in EDS analysis of polished samples. Chemical formulae and identification of mineral species of metalbearing phases were thus calculated from atomic ratios between constituent elements with sufficient accuracy. A comparison between EDS measurements in polished and rough particle samples using the Welch's t-test showed that about 38 % of studied metal-bearing phases could be identified with sufficient reliability by EDS analysis of rough particle samples. The results of this study demonstrated that elemental composition of metal-bearing phases in polished and rough particle samples was mostly determined with sufficient precision and accuracy using EDS analyses. [ABSTRACT FROM AUTHOR]