- © The Mineralogical Society Of America
When two solutes crystallize simultaneously from an aqueous phase and have similar crystal structures, a solid solution is likely to form. Indeed, although often disregarded, solid solution-aqueous solution (SS-AS) effects are ubiquitous in both natural and industrial crystallization processes. In nature, and particularly on the Earth’s surface environments, the crystallization of minerals from multicomponent aqueous solutions provokes in most cases the formation of solids with more or less wide compositional ranges, i.e., solid solutions. Moreover, the interaction between existing minerals and water frequently leads to surface precipitation and dissolution-recrystallization processes, in which a number of substituting ions (major, minor, or trace) redistribute to adapt to the new conditions.
The study of SS-AS relationships between minerals and solutions can provide very valuable information about natural waters, contamination of soils and aquifers, and global element cycles. For instance, in diagenetic studies of sedimentary rocks, the minor and trace element concentrations are commonly used to infer the composition of the crystallizing fluids and have been demonstrated to play a major role in the dissolution-recrystallization processes that lead to the formation of authigenic minerals (e.g., Böttcher 1997b; Rimstidt et al. 1998; Kulik et al. 2000; Mucci 2004). Likewise, the concentrations of specific minor and trace elements in calcite and aragonite precipitated by marine organisms have been shown to correlate with various parameters of the growth environment, including temperature, salinity, nutrient levels, carbonate concentration, and water chemistry. These findings suggest that compositional signatures recorded in biogenic carbonates can be powerful tools in reconstruction of the past from the fossil record (e.g., Rosenthal et al. 1997; Stoll et al. 2002; Rickaby et al. 2002). Obviously, for these proxies to be effective, it is essential to rigorously investigate the underlying physical and chemical mechanisms both in the absence and in the presence …