Transformation of Vaterite into Cubic Calcite in the Presence of Copper(II) Species

Abstract

By a simple washing of vaterite with ultrapure water, it transforms rapidly into cubic calcite. When the solid is washed with Cu2+ solutions, the transformation depends on the concentrations of the copper solutions applied in the process. For concentrations of 10-4 mol dm-3, a certain delay in the transformation process is detected, and the obtained cubic calcite seems to be in the form of CuxCa1-xCO3. For concentrations of 10-3 mol dm-3, the vaterite structure remains stable with time, and this stability seems to be correlated with the saturation of the surface by Cu2+ in place of Ca2+. For concentrations of 10-2 mol dm-3, a mixture of vaterite, aragonite, cubic calcite, and malachite is obtained during the transformation process.