The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
... Phase-contrast TEM micrographs (HR-TEM) reveal
a coherent crystal structure with subtle moirć superlattice fringes in (211), manifested as an
enhanced contrast ridges separated for #2 nm (Figure 3b). The chemical composition of
the arsenopyrite crystal was analysed inside the TEM chamber by ene ...
... from the vacuum chamber to the TEM, with air exposure <5 min.
Figure 6. (a) Edge of arsenopyrite grain with marked regions for FFT patterns (I-III) and magnified
(b) HR-TEM micrograph of the surface layer with corresponding, FFT power spectra. (c) Overview
TEM micrograph with corresponding, FFT ...
... from this locality are composed of crystals large enough for
the conventional preparation of the oriented thin foils for TEM analyses.
3.2. Transmission Electroh Microscopy (TEM)
The arsenopyrite samples are stable under an electron beam, allowing, prolonged
exposure without noticeable deterioration ...
Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik. "Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)" in Crystals, MDPI AG (2023). https://doi.org/10.3390/cryst13020278
