High-resolution XANES S L_3,2 edge spectra collected from a series of iron-bearing sphalerite(Zn,Fe)S minerals

High-resolution S L_3,2-edge XANES spectra have been collected from a series of high-quality sphalerite samples. Each of the sphalerite samples examined has a characteristic iron concentration, and the range is from <0.01 to 14.79 wt% Fe. The structures of the S L_3,2-edges are investigated by comparing ab initio calculated spectra with experimentally measured S L_3,2-edge spectra collected from synthetic ZnS sphalerite. The theoretical and experimental data provide evidence that S 2p electron transitions to empty S 3s and S 3d states can occur across an energy range above the absorption edge. A chemical shift, associated with iron to sulphur bonds, is identified, and for the first time, a pre-edge feature associated with S-Fe bonding in sphalerite is observed.