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EMU Notes in Mineralogy - volume 10
Ion partitioning in ambient-temperature aqueous systems

Chapter 2: Effects of kinetics and mechanisms of crystal growth on ion-partitioning in solid solution–aqueous solution (SS–AS) systems

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Andrew Putnis

Ion-partitioning between aqueous solutions and growing crystals is controlled by both the equilibrium thermodynamics of the solid solution–aqueous solution system and departures from equilibrium. In this chapter the various factors which influence ion distribution coefficients are reviewed with specific emphasis on the role of supersaturation on crystal-growth mechanisms and growth rate, the role of the surface chemistry and structure of the crystal in controlling ion incorporation and finally on the role of organic molecules and background electrolytes in modifying the dynamics of water exchange around the ions which are potentially incorporated into a growing crystal. Examples to illustrate the general principles involved are taken from room-temperature experimental studies of crystal growth in solid solution–aqueous solution systems.

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