The yellow seal stone from northern Laos is one possible substitute for the Tianhuang Stone, most famous Chinese stone, because of its similar to orange-yellow appearance and same main mineral composition. colour causation was studied. samples’ phase, micro-morphology chemical components were studied by Raman spectroscopy, scanning electron microscopy (SEM) with energy disperse spectroscopy (ED...

The distribution of Ga and A1 atoms within the octahedral sheets of synthetic goethites has been investigated by XRD and Ga K-edge XANES and EXAFS spectroscopies. XRD results indic te a solid solution between goethite (aFeOOH) and GaGoe4 (40 mol% of Ga). The XANES data indicate the presence of &a in the solid solution. The fitting procedures for EXAFS spectra show no evidence of preferential oc...

and anatase, but it does not sorb significantly to pure clay minerals or soil organic matter (Fordham and NorIn order to make sound decisions regarding arsenate contamination rish, 1979, 1983; Jacobs et al., 1970). Arsenate sorption in soil and water environments, it is necessary to have a thorough understanding of the mechanisms of arsenate sorption and desorption on soils and soil components ...