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 invest igated. The results were compared with those of synthetically precipitated calcite, the main inorganic constituent (>98%) of the tested marbles. The d issolution process at solution undersaturation near equilibrium in all case s showed a linear dependence. of the rates of dissolution on the relative s olution undersaturation. The dissolution was found to be polynuclear, surfa ce diffusion controlled. Morphological examination of the specimens showed that dissolution proceeds through formation of steps, cracks, pores, and la yerwise disintegration, corroborating the conclusion from the kinetics resu lts. Powdered marble is suggested to be an excellent model system for the i nvestigation of marble dissolution as it exhibited remarkable similarities with the dissolution of whole marble blocks.