Patterns in the compositions, properties, and geochemistry of carbonate minerals

摘要: The diversity of carbonate minerals is remarkable, if largely unappreciated. For example, 277 carbonate-bearing have been recognized, and among them are 158 pure carbonates cations with valences from 1+ to 6+. other 119 additionally contain chloride, fluoride, borate, sulfate, phosphate, arsenate, arsenite, antimonate, or silicate groups, combinations those anions. However, anions not uniformly distributed, so that there no bicarbonates simple highly-charged cations, few hydrated OH-bearing monovalent U-bearing than CO3 2, OH−, O2−. On the hand, divalent Al carbonates, fluoride-bearing rare-earth elements remarkably numerous. Many these trends can be related coordination chemistry in solutions which form. Among nearly all minerals, ionic potential a major control on extent hydration. Degree hydration turn hardness, density, solubility. positions spectroscopic peaks vary linearly cation radius mass, although such usually exist only within crystallographic groups defined by periodic table. In contrast, geochemical parameters, as solubility fractionation oxygen isotopes, degree ofcation fit 6-fold 9-fold site rhombohedral orthorhombic linear variation size. same true for distribution coefficients calcite aragonite. Patterns thus emerge compositions, properties, geochemistry cationic type influence composition, mass physical but parameters. These patterns allow qualitative prediction mineral properties help explain origins some problems petrology.