Dissolution of pentelic marble at alkaline pH

The kinetics of dissolution of powdered Pentelic marble from two different sites located on Mount Pentelicon of Attica, Dionysos and Cave, were investigated. The results were compared with those of synthetically precipitated calcite, the main inorganic constituent (>98%) of the tested marbles. The dissolution process at solution undersaturation near equilibrium in all cases showed a linear dependence. of the rates of dissolution on the relative solution undersaturation. The dissolution was found to be polynuclear, surface diffusion controlled. Morphological examination of the specimens showed that dissolution proceeds through formation of steps, cracks, pores, and layerwise disintegration, corroborating the conclusion from the kinetics results. Powdered marble is suggested to be an excellent model system for the investigation of marble dissolution as it exhibited remarkable similarities with the dissolution of whole marble blocks.