Selenium incorporation into calcite and its effect on crystal growth: An atomic force microscopy study

A thermodynamic adsorption/entrapment model for selenium(IV) coprecipitation with calcite

“…In regard to the comparison of AFM and MFR growth rates, it is 1064 important to mention that a step density of 0.4 µm --1 has been arbitrarily chosen in order to transform 1065 AFM step velocities in nm/s to macroscopic growth rates in nmol/(m 2 s). According to AFM images 1066 (Renard et al, 2013) the average step density on the slopes of growth hillocks is about 10 µm --1 . 1067…”

“…Considering the large effect selenite has on the morphology of growth features (Renard et al, 2013) Gibbs free energy of a virtual endmember, which by definition makes an ideal solid solution with the 1098 host phase. In contrast to the experiment, our DFT result suggests a much lower stability of the virtual 1099 bulk endmember, log 10 (K SP (CaSeO 3_bulk )) = 0.5 ± 1.7.…”

Se(IV) uptake by Äspö diorite: Micro-scale distribution

“…However, carbonate is not expected to sorb significantly in the rock matrix or to influence the distribution of complex Se forms (Crawford, 2010). Selenium incorporation into calcite structure, in the form of oxyanions, by replacing the carbonate group has also been proposed (Renard et al, 2013).…”

Chemical Vapour Generation for Tin Determination in High-content Calcium Matrix by Inductively Coupled Plasma Atomic Emission Spectrometry

“…Fe, Mn, Cu and Zn) can easily be incorporated into calcite structure and ion with greater radius (Cd, Ba and Pb) can be incorporated into aragonite structure. 15,20 Consequently, radius of tin ion is slightly smaller than radius of lead and hence is prevalent in CESA sample rather than in PJSC sample.…”

“…19 Different mineralogical structure of shell layers implies incorporation of metals with different ionic radius into calcite or aragonite layer. 20 Therefore, for the control of tin presence in rhombohedra calcite and orthorhombic aragonite the analysis of two laboratory samples was performed. Samples were represented by powdered shells of Pecten jacobaeus Standard Calcite (PJSC) and Cerastoderma Standard Aragonite (CESA) which mineralogical purity was confirmed by X-ray diffraction.…”